ISSN-0974-1550
ENVIS NEWSLETTER
MICROORGANISMS AND ENVIRONMENT MANGEMENT (Sponsored by Ministry of Environment, Forest & Climate Change, Government of India)
VOLUME 15 ISSUE 3 Jul. - Sep. 2017
ENVIS CENTRE Department of Zoology
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Cover page : Honey mushroom fungus Armillaria sp. The largest organism in the world, when
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ISSN - 0974 - 1550
Volume 15 | Issue 3 | Jul. - Sep. 2017
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ENVIS Newsletter Vol.15/ Issue 3/ Jul. - Sep. 2017
1
CONTENTS Page
No. From the Coordinator’s Desk!
Dear Readers,
Greetings!
Search for new compounds in biotechnological and
biomedical sectors has increased. Even alternate sources for
the existing compounds are in demand as the current
production of some compounds is insufficient. Of the various
sources explored, the eukaryotic microorganisms fungi, offer
promising solutions. The fungi in the environment are utilized
mainly for bioremediation, bio fertilizers, food crops
development etc. The bioactive compounds of fungi are used
in treatment of infectious disease, cancer and antibiotic
development etc. The diversity of fungi in ecosystem is vast
and to understand their interaction with other microorganisms,
plants and animals is essential for innovative and effective
developments.
In this context, the present issue contains a research
article that explains about stimulation and production of taxol
from a fungus with other interesting topics such as alternative
antimicrobial compounds from wastewater, how microbes may
influence our behavior, use of fungi for assessing radioactivity
of environment and many more. Hope this issue would bring
an awareness on the importance of the fungi and their
associated studies.
Dr. C. Arulvasu
Kindly send your feedback @
www.envismadrasuniv.org/send_feedback.php
For further details, visit our website.
www.dzumenvis.nic.in: www.envismadrasuniv.org
SCIENTIFIC ARTICLE
Stimulation of taxol production by
Pestalotiopsis breviseta (sacc.) Steyaert using
biotic and abiotic elicitors Kathiravan*. G, Arulvasu. C, Meenashree. B and
Manickamoorthi. N
2
RESEARCH REPORTS
Alternative antimicrobial compounds could
come from wastewater
6
Fungi that evolved to eat wood offer new
biomass conversion tool
7
How microbes may influence our behavior 8
ONLINE REPORTS
Storming the cellular barricades to fight
fungi
9
Hunt is over for one of the top 50 most-
wanted fungi
9
NEWS
Fungi are key players of the deep biosphere 11
Fungi can be used as biomonitors for
assessing radioactivity in our environment
11
ABSTRACT OF RECENT
PUBLICATIONS
12
E - RESOURCES
EVENTS
SCIENTIFIC ARTICLE
Stimulation of taxol production by Pestalotiopsis breviseta (sacc.) Steyaert using
biotic and abiotic elicitors Kathiravan. G1*, Arulvasu. C2, Meenashree. B3 and Manickamoorthi. N3
1Department of Botany, Ramakrishna Mission Vivekanandha College, Chennai. 2 Department of Zoology, University of Madras, Chennai. 3Department of Biotechnology, Vels University,
VISTAS, Chennai
Keywords:
Fungal Taxol
Elicitors
Anticancer Drug
Biosynthesis
2
ABSTRACT
Coelomycetous fungi Pesalotiopsis breviseta (Sacc.) Steyaert was screened for the production of taxol an
anticancer drug. Taxol production was confirmed by Ultra Violet (UV) spectroscopy, Infra-Red (IR) spectroscopy,
High Performance Liquid Chromatography (HPLC) and Liquid Chromatography Mass Spectrum (LC - MS)
analysis. The compound produced by the fungus with and without elicitors was compared with authentic taxol,
identified and confirmed as taxol. Minimum of 150 µg/L taxol was produced with biotic fungal elicitor, while 160
µg/L was produced without any elicitors. Maximum of 250 µg/L taxol was produced with abiotic elicitor, copper
sulphate (CuSO4). The tested fungus P. breviseta, has a great potential for commercial exploitation in the future, for
better taxol production.
Introduction
Taxol is the commercial trade name used by Bristal-
Myers Squibb for the compound, paclitaxel. It has poor
water solubility and a complex chemical structure. Taxol
along with a chemically similar analogue, Taxotere
(Docetaxel) (Guenard et al., 1993) has unique anti-tumour
mechanism of action. The drugs are believed to block cell
cycle progression during mitosis by binding to and
stabilizing microtubules (Schiff et al., 1979, Nicolaou et al.,
1994). During cell division, taxol interferes with the
development of the microtubules needed for cell duplication
thus inhibiting the faster growing tumor cells. This is
different from other anti-cancer agents that work by
interfering with the DNA of tumor cells.
Clinical development of taxol progressed slowly
because of the extremely small amount of drug obtained
from the crude bark extract of the tree Pacific yew. Taxol
was approved for the treatment of ovarian cancer by the
Food and Drug Administration (FDA) in 1992 and
subsequently in the same year was used for treatment of
breast cancer. Since then clinical use of taxol had increased
and its use has been extended for treatment of lung cancer,
squamous cancers of the head and neck and various other
cancers (Eisenhaver and Vermorken, 1998). Naturally
Pacific yew grows slow but under intensive nursery culture,
can grow quite quickly. The tree lives 200-300 years with
some species 400 years or more and Taxol is found in small
quantities (0.001 to 0.01% of the dry bark weight) and the
content can vary in them. It is generally
considered to take 3 to 10 trees per patient. Based on the
year 1992 data from the US Forest Service, 36000 trees are
required to provide 327200 kg of bark (about 9 kg/tree)
from which only 24 kg of taxol can be extracted (about 0.66
g/tree). Hence there is an urgent need to search for the
alternative sources for this promising anticancer drug.
The plant cell culture of Taxus species appeared to be
promising to obtain taxol and related taxane compounds.
Ketchum and Gibson (1996) investigated this using free and
immobilized cells of Taxus cuspidata using perfusion
culture reactors and achieved continuous taxol production at
a rate of 0.3 mg/g DCW (dry cell weight) per day for 40
days.
The presence of various microorganisms from the bark
of the yew tree was found to be capable of producing taxol.
The fungi Taxomyces andreanae (Stierle et al., 1993)
isolated from the inner bark of a yew tree growing in North-
western Montana was able to produce taxol and other
taxanes in denovo fashion when grown in semi-synthetic
liquid media but the yield was very low (24-50 ng/L).
Pestalotiopsis microspora, a coelomycetous endophyte in
Taxus brevefolia was observed to produce taxol (Stroebel et
al., 1996) in considerable amount more than the Taxus sp.
There are atleast 12 distinct enzymatic reactions involved in
taxol biosynthesis (Croteau et al., 1995; Floss and Mocek,
1995). The genetic manipulation of fungi could be achieved
more easily than that of plants and it may be possible to
improve the production significantly with the help of
genetic engineering. Keeping this in mind there is an urgent *Corresponding author.
E-Mail address: [email protected]
3
Thin layer chromatography (TLC):
Chromatography was done on 0.25 mm Merck precoated
silica gel plates. The plates were developed successively in each
of the following solvent systems as follows; A - Chloroform/
Methanol 7:1 v/v, B - Chloroform/ Acetonitrile 7:3 v/v, C - Ethyl
acetate/2-Propanol 95:5 v/v, D- Methylene chloride/ Tetra hydro
furan 6:2 v/v and E- Methylene chloride/ Methanol/
Dimethylformamide 90:9:1 v/v/v. Taxol was detected with 1%
w/v vanillin/sulphuric acid (H2SO4) reagent after gentle heating
(Cardellina, 1991). It appeared as a bluish spot fading to dark
grey after 24 hours.
Ultra Violet (UV) spectroscopy
The sample containing taxol was analysed
spectroscopically. After chromatography, the area of plate
containing putative taxol was carefully removed by scrapping
off the silica at the appropriate Rf and exhaustively eluted with
methanol. The UV spectral analysis of fungal sample was
superimposed on authentic taxol at 273 nm.
High Pressure Liquid Chromatography (HPLC)
Isolated samples were analysed by HPLC (Shimadzu 9A
model) using a reverse phase C18 column with a UV detector.
Sample (20 µl) was injected each time and detected at 232 nm.
The mobile phase was methanol/acetonitrile/water (25:35:40
v/v) at flow rate of 1.0 ml min-1. Taxol was quantified by
comparing the peak area of the samples with that of the standard
using the formula,
Taxol Content = Standard concentration × Total area of the sample
Total area of the standard
Infra-Red (IR) spectroscopy
The IR spectra of the compound were recorded on
Shimadzu FT IR 8000 series instrument. The purified taxol was
ground with spectra grade potassium bromide (KBr) (1:10)
pressed in to pellets under vacuum using spectra lab Pelletiser
and compared with authentic Taxol. The IR spectrum was
recorded in the region 4000 – 500 cm-1nm.
Liquid Chromatography - Mass Spectrometry
The sample from Pesalotiopsis breviseta was subjected to
electron spray mass spectroscopic analysis for the confirmation
of presence of taxol. The sample was dissolved in
methanol:water:acetic acid (50:50:1 v/v). It was injected with a
spray of 2 µL and spray voltage of 50 V by the loop injection
method.
need to search for the alternative sources for this
promising anticancer drug. The present study deals with
the stimulation of selected endophytic fungi Pesalotiopsis
breviseta for the production of taxol.
Materials and methods
Experimental designing
Biotic and abiotic elicitors were used for enhancement
of taxol production from the fungus. The taxol produced
without any elicitors by the fungus served as control. One
week after the inoculation of fungi in M1D broth media,
the abiotic elicitor copper sulphate (CuSO4) 50 mg/L was
added. Later after two weeks another dose of the abiotic
elicitor of same concentration was elicitated. For biotic,
fungal elicitors was used. Initially the fungi were
inoculated in M1D broth media without sucrose for a week
after which it was elicitated using 50 mg/L of fungal
carbohydrate.
Extraction of taxol
The extraction procedure was followed by the
method of Strobel et al. (1996). The fungus was grown
in 2 litre Erlenmeyer flasks containing 500 ml of M1D
medium as described in experimental setup and
supplemented with 1g soytone L-1 (Pinkerton and
Strobel, 1976). After incubation for 21 days at 26 ± 1°C
the culture filtrate was obtained by passing through
four-layered cheesecloth. To avoid fatty acid
contamination 0.25 g of sodium carbonate (NaCO3) was
added to the filtrate and extracted with equal volumes of
solvent dichloromethane twice. The organic phase was
collected and evaporated to dryness under reduced
pressure at 35ºC. The dry solid residue was re-dissolved
in methanol and loaded on a 1.5 X 30 cm column of
silica gel (Baker 40 micron). Elution of the column was
performed in a stepwise manner starting with 70 mL of
100% methylene chloride followed by mixtures of
organic solvents methylene chloride:ethyl acetate at
different proportions 20:1, 10:1, 6:1, 3:1 and 1:1 v/v.
Fractions were subjected to TLC and those having same
mobility as the authentic taxol were combined and
evaporated to dryness. The compound obtained was
analysed further for the presence of taxol in the fungal
samples.
4
Results and Discussion
In the present study the test fungus Pestalotiopsis
breviseta a Coelomycete, was tested for production and
enhancement of taxol by biotic and abiotic elicitors in a
semi-synthetic medium M1D, for its growth. The taxol
was extracted using dichloromethane and the solvent
was removed by evaporation under vacuum, the
resulting residue was re-dissolved in methanol and
treated as the sample containing taxol to further studies
for its confirmation.
Thin layer chromatography (TLC) was developed
on a 0.25 mm (10 x 20 cm) silica gel plate in different
solvent system with authentic taxol (Sigma, Cat. No. T-
7402) as standard. The sample showed identical Rf and
UV characteristics with the standard and reacted
positively with Vanillin/H2SO4 spray reagent, yielding a
blue spot which turned grey after 12 - 24 h. After
chromatography the taxol was eluted with methanol.
The UV spectral analysis of samples were
superimposed on that of authentic taxol with two
maxima at 273 nm and 235 nm which showed that the
purified sample might to be a taxol (Fig.1a-d).
amount of taxol produced by the fungus was quantified by
comparing the peak area of the samples (Fig. 2a-d) with that of
the taxol standard using the methods and formula described
earlier. The effect of biotic and abiotic elicitors on the fungus
Pestalotiopsis breviseta for taxol production was quantified.
The maximum taxol production was observed in the medium
containing chemical elicitor CuSO4 (250 μg/l) and minimal of
150 μg/L of taxol in medium containing fungal elicitor. The
cultures grown without any elicitors i.e. control produced 160
µg/L. Thus further convincing evidence for the identity of taxol
was obtained by High Pressure Liquid Chromatography.
Fig. 1: Ultra Violet (UV) Absorption of standard taxol
against taxol isolated from the fungus under different
conditions (control, biotic and abiotic elicitors)
The sample containing taxol was analysed by HPLC
using a reverse phase C18 column with a UV detector for the
quantification using the authentic taxol as standard. The
Fig. 2: High Pressure Liquid Chromatography (HPLC) analysis
of standard taxol against taxol isolated from the fungus under
different conditions (control, biotic and abiotic elicitors)
The presence of taxol was further confirmed by using
Infra-Red analysis of the compound isolated from the fungus.
The appearances of bands convincingly illustrated the identical
feature of the taxol isolated from the fungus without any
elicitor (Control) (Fig. 3b) and taxol isolated from the fungus
treated with abiotic elicitor (Fig. 3c) with the authentic taxol
used as standard (Fig. 3a). Infra-Red analysis showed that the
presence of alcoholic O - group in the sample is evident by its
OH stretching vibration at 3448 cm-1. The aliphatic CH -
stretch at 2931 cm-1, the C=O stretch positioned 1724 cm-1
and the amide C=O stretch is shifted to lower value at 1652 cm-
1. The intense peak
at 1247.16 cm-1 is due to COO stretch. The alkyl C-O stretch of
ester is observed at 1072 cm-1. The peak at 707 cm-1 is due to
aromatic C, H bond. In extracted sample though the intensity of
the bands are very much diminished in the fingerprinting region,
appearance of overtone 2362 cm-1 convincingly illustrates the
identical nature of the extracted sample with authentic taxol. The
taxol isolated from fungus treated with biotic elicitor was not
subjected to further analysis as its yield was very low
comparatively.
Fig. 3a&b: (a) IR spectrum of Authentic Taxol and (b) taxol
produced by Pestalotiopsis breviseta without elicitors (Control).
Fig. 3c: IR spectrum of Taxol extracted from Pestalotiopsis
breviseta using abiotic elicitor.
The fungal compound produced an identical LC mass
spectrum when compared with the standard. Characteristically,
authentic taxol yielded both an (M+H)+ peak at 855 and an
(M+Na)+ peak at 856 (Fig. 4a) and by comparison, fungal taxol
produced in the presence of abiotic elicitor also had these
characteristics peak (Fig. 4b). Based on these results it was
confirmed that the compound produced by the fungus
Pestalotiopsis breviseta was taxol.
Fig. 4a: Liquid Chromatography-Mass Spectrometry (LC-MS)
analysis of standard taxol
Fig. 4b: Liquid Chromatography-Mass Spectrometry (LC-MS)
analysis of taxol isolated from Pestalotiopsis breviseta treated
with abiotic elicitor.
The amount of taxol produced by the fungus could be
increased by improving culture techniques, addition of various
elicitors, application of genetic engineering and gene
expression studies. This would lead to improved production of
taxol and overrule its production from plant source.
References
Cardellina, J. H. (1991). HPLC separation of taxol and
cephalomannine. J. Liq. Chromatogr. 14 (4): 659 - 665.
Croteau R, Hefner J, Hezari M , Lewis NG: Flores, H. E. and
Gustine. D. I. (Eds.) (1995). American society of plant
physiology. Phytochemicals and Health.
Eisenhauer, E. A. and Vermorken, J. B. (1998). The taxoids.
Drugs. 55 (1): 5 - 30.
Floss, H. G. and Mocek, U. (1995). Biosynthesis of taxol. In
Taxol: science and applications. CRC Press, Boca Raton,
Florida. pp. 191-208.
Guenard, D., Gueritte-Voegelein, F. and Potier, P. (1993).
Taxol and taxotere: discovery, chemistry, and structure-
activity relationships. Acc. Chem. Res. 26 (4): 160 - 167.
Ketchum, R. E. B. and Gibson, D. M. (1996). Paclitaxel
production in suspension cell cultures of Taxus. Plant Cell,
Tissue Organ Cult. 46 (1): 9 - 16. 5
Nicolaou, K. C., Yang, Z., Liu, J. J., Ueno, H., Nantermet, P. G.,
Guy, R. K. and Sorensen, E. J. (1994). Total synthesis of
taxol. Nature. 367 (6464): 630 - 634.
Pinkerton, R. and, Strobel, G (1976).: Serinol as an activator of
toxin production in attenuated cultures of H. sacchari. Proc.
Natl. Acad. Sci. USA. 1976; 73: 4007 - 4011.
Schiff, P. B., Fant, J. and Horwitz, S. B. (1979). Promotion of
microtubule assembly in vitro by taxol. Nature. 277 (5698):
665 - 667.
Stierle, A., Strobel, G. and Stierle, D. (1993). Taxol and taxane
production by Taxomyces andreanae, an endophytic fungus of
Pacific yew. SCIENCE-NEW YORK THEN
WASHINGTON, 260: 214 - 214.
Strobel, G., Yang, X., Sears, J., Kramer, R., Sidhu, R. S. and Hess,
W. M. (1996). Taxol from Pestalotiopsis microspora, an
endophytic fungus of Taxus wallachiana. Microbiol. 142 (2):
435 - 440.
RESEARCH REPORTS
Municipal wastewater may become a key ally in the fight
against antibiotic-resistant disease-causing bacteria and fungi, a
new study has found.
According to Dr Thando Ndlovu, a postdoctoral researcher in
the Department of Microbiology at Stellenbosch University,
certain bacteria present in municipal wastewater produce
antimicrobial compounds or biosurfactants that can help to
prevent the growth of antibiotic-resistant microorganisms which
cause serious infections in humans. Ndlovu had recently obtained
his doctorate in Microbiology at Stellenbosch University under the
supervision of Prof. Wesaal Khan from the same department.
He said that the rapid increase in the emergence of antibiotic-
resistant bacteria was a major reason behind his search for new
antimicrobial compounds. As part of his research, Ndlovu
collected wastewater samples and also carried out molecular and
microbiological tests in a laboratory on various biosurfactants-
producing bacteria found in these samples. He isolated two
bacterial strains whose biosurfactants proved effective against
antibiotic-resistant disease-causing bacteria. Biosurfactants are
compounds produced naturally by bacteria, fungi or yeasts and
they have been commercially utilized in shampoos, shower gels,
and household cleaning products. They are also used in food,
agriculture, cosmetic and medical industries as well as in
environmental bioremediation to prevent the spread of
spoilage and disease-causing bacteria.
The biosurfactants produced by two bacteria in his study
prevented the growth of major disease-causing bacteria such
as methicillin-resistant Staphylococcus aureus and
gentamicin-resistant E. coli which can lead to life-threatening
infections in humans. This finding is promising as worldwide
reports on the number of deaths caused by antimicrobial
resistant microorganisms that are becoming increasingly
difficult to treat with currently available drugs.
The discovery of novel antimicrobial compounds is a
priority and biosurfactant compounds could be used to
develop new antibiotics for treatment of various infections
caused by antibiotic resistant bacteria and eventually replace
ineffective antibiotics in future. Ndlovu showed in his study
that municipal wastewater is ideal for the isolation of diverse
biosurfactant-producing bacteria that could be utilized in the
production of such compounds for commercial use.
While numerous studies have reported on the isolation of
biosurfactant-producing bacteria from contaminated soil and
terrestrial environments, the current study indicated that
municipal wastewater could be exploited for the isolation of
diverse biosurfactant-producing bacterial strains.
Biosurfactant-producing bacteria thrive in polluted
environments such as contaminated soil or water. These
bacteria also have the ability to outcompete other bacteria in
the same environment because the biosurfactant compounds
help them to absorb nutrients and to protect them from toxic
materials.
Fig. South African microbiologist, Dr. Thando Ndlovu in his
laboratory in the Department of Microbiology, Stellenbosch
University.
Image credit: Stefan Els
6
Alternative antimicrobial compounds
could come from wastewater
Ndlovu adds that biosurfactant compounds can be used to
reduce the use of synthetic antimicrobial agents for various
purposes such as cleaning and coating agents to prevent the
build-up of disease-causing and spoilage bacteria. As far as
future research is concerned, Ndlovu said that he is now focusing
on the application of biosurfactant compounds with antimicrobial
properties.
Source: www.sciencedaily.com.
Twenty years ago, a microbiologist and his colleagues
discovered a unique system that some microorganisms use to
digest and recycle wood. Three orders of brown rot fungi have
now been identified that can break down biomass, but details of
the mechanism were not known. Using several complementary
research tools, Goodell and colleagues reported new details of
this unexpected mechanism at work, one that surprisingly does
not involve enzymes, the usual accelerators of chemical
reactions. Basidiomycota brown rot fungi use a non-enzymatic,
chelator-mediated biocatalysis method that is very different than
that used by any other microorganism studied. Chelators are
organic compounds that bind metal ions and in this case they also
generate hydroxyl radicals to break down wood and produce
simple building-block chemicals.
Described by collaborators at Oak Ridge National
Laboratory as a paradigm shift in understanding fungal
biocatalysis for biomass conversion the findings appear in the
journal of Biotechnology for Biofuels. Goodell said their research
on fungal bioconversion systems looks at a novel mechanism that
has potential use in bio-refineries to deconstruct woody biomass
for conversion into platform chemicals for biopolymers or energy
products.
Brown rot fungi appear in both the northern and southern
hemispheres and are some of the most common decay fungi in
North America. Because they evolved relatively recently, there
are fewer brown rot species compared to older white rot species.
Goodell said that because of their rich efficiency in degrading
wood particularly in degrading softwoods. Brown rot fungi have
now dominated by recycling approximately 80 percent of the
softwood biomass carbon in the world, found mostly in the great
forests of the northern hemisphere.
Goodell points out that most microorganisms use enzymes
to break down compounds, but enzymes are huge molecules
and physiologically expensive to produce because they contain
so much nitrogen. He noted that scientists used to think that
these fungi would make holes in the cell wall that would let in
the big enzymes a sort of pretreatment model. But now they
have explained how it works. The fungi in their study used a
non-enzymatic, catalytic chelator-mediated Fenton system, a
very simple process that makes use of hydrogen peroxide
which is also generated by the fungal system and iron found in
the environment. He adds that he and his colleagues believe the
brown rot fungi's efficiency comes from their use of the
chelator-mediated Fenton system rather than the use of
enzymes exclusively, as white rot fungi do.
Goodell noted that this group of brown rot fungi generates
hydroxyl radicals at a distance that is away from the fungus so
the radicals won't damage themselves while breaking down
wood. Hydroxyl radicals are very damaging to cells, the most
potent oxidizing agents known in biological systems.
For this work, Goodell and his colleagues including his
collaborator Jody Jellison, now director of the Center for
Agriculture, Food and the Environment at UMass Amherst,
used a suite of investigative methods including Small Angle
Neutron Scattering (SANS), Sum Frequency Generation (SFG)
Spectroscopy, Fourier Transform Infra-Red (FTIR) analysis,
X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM)
and Transmission Electron Microscopy (TEM) to fully
describe the process.
Goodell said that these fungi do produce a limited number
of enzymes but they come into play after the non-enzymatic
action conversion by the fungi using chelators. The chelators
are secondary metabolites, whose function is not easily
followed using omics techniques such as genomics. Using
many advanced techniques they found some very small, low-
molecular-weight compounds working their way into the cell
wall.
Goodell and Jellison relate a process that begins with the
fungi in the lumen - the hollow space found inside plant cells.
Using their hyphae, thread-like growth filaments, the fungi
then mount a biochemical attack on the wood cell components.
They explained that this group of fungi evolved a way to
break down the wood substrate by first diffusing chelators into
the cell wall. The fungus makes the chelator and produces 7
Fungi that evolved to eat wood offer
new biomass conversion tool
hydrogen peroxide from oxygen and together they start to digest
the cell wall into the sugar found in the basic building block of
wood, glucose, which the fungus uses as food. This is how these
fungi are eating the wood.
Source: www.sciencedaily.com.
Stress, anxiety and depression are emotions we all feel at
some point in our lives and some people feel them to a greater
degree than others. Part of the human experience, right?
In a recent study, John Cryan, a researcher at the APC
Microbiome Institute at University College Cork in Ireland and
his colleagues reported a link between the microbiome and fear.
By examining mice with and without gut bacteria, they
discovered that the germ-free mice had blunted fear responses
(Mol. Psychiatr. doi:10.1038/mp.2017.100, 2017). Their findings
may pave the way for the development of novel treatments for
anxiety-related illnesses, including posttraumatic stress disorder.
“It may seem odd that my research focuses on the gut if I‟m
interested in the brain. But when we think of how we express
emotion in language, through sayings like „butterflies in your
tummy‟ and „gut feeling,‟ it isn‟t surprising that they‟re
connected” says John.
Researchers at Kyushu University in Japan were the first to
show in 2004, that bacteria in the gut can influence stress
responses, prompting many subsequent investigations. Yet
despite mounting research scientists remained uncertain about
exactly how the gut microbiome affects the brain. While some
bacteria influence the brain through the vagus nerve other strains
seem to use different pathways. It is known that the population of
the gut microbiome begins in early life, and recent research
suggests that disruptions to its normal development may
influence future physical and mental health (Nat. Commun.
6:7735, 2015).
Researchers are finding that this gut-brain connection could
have clinical implications as influencing the gut microbiome
through diet may serve to ameliorate some psychiatric disorders.
Together with University College Cork colleague Ted Dinan,
Cryan coined the term “psychobiotics” in 2013 to describe live
organisms that when ingested produce health benefits in patients
with psychiatric illness. These include foods containing
probiotics and live strains of gut-friendly bacteria.
While there are many rodent studies linking probiotics and
mental health, UCLA biologist Emeran Mayer and his
colleagues were the first to test them in humans, using
functional magnetic resonance imaging (fMRI) scans to assess
the results. After administering probiotic yogurt to a group of
healthy women twice a day for four weeks, the researchers
found that the women had a reduced brain response to negative
images (Gastroenterology, 144:1394-401, 2013). Having
conducted this study on healthy participants, Mayer is reluctant
to conclude that probiotics can cure mental illnesses such as
anxiety. He said it to be a complex emotion, not just a reflex
behavior like in the mouse. However, Mayer told he is very
supportive of the potential of prebiotics, fiber-rich foods that
promote the growth of beneficial bacteria in the gut.
Researchers at Deakin University in Australia recently
trialed a Mediterranean-style diet, which is predominately
plant-based and fiber-rich in a group of adults with major
depression. They found that one-third of the participants
reported a significant improvement in symptoms after 12
weeks on the diet (BMC Medicine, 15:23, 2017).
Just as activity in the gut seems to affect the brain, mental
stress can lead to intestinal problems. Scientists have
demonstrated this in research on irritable bowel syndrome. For
example, a study by Mayer and colleagues linked early-life
emotional trauma to an increased risk of developing the bowel
disorder (Clin. Gastroenterol. Hepatol. 10:385-90, 2012).
As data on the brain-gut axis accumulates, many scientists
are taking notice. Trinity College Dublin researcher Shane
O‟Mara said that there is a great potential in this area but
cautioned that it is too early to say whether targeting the
microbiome will play a role in psychiatric treatment.
University of Manitoba gastroenterologist Charles Bernstein
also feels the research is promising but believes that we are far
from manipulating the microbiome to treat mental health
disorders. Those spearheading this research are equally aware
of the need for more studies, particularly in human subjects,
but they are hopeful that change lies ahead.
“I‟m almost certain that in several years, diet will be
considered one branch of therapy for many mental illnesses,
alongside medication and psychiatric treatments,” says Mayer.
“People with severe mental illness will still need something
very strong, but this is a useful adjunctive,” agrees Cryan. “I
think when we go to our GP in future, we will not only have 8
How microbes may influence our
behavior
blood tests, we will have the microbiome tested.”
“Within five years, I hope to see more clinical trials that
demonstrate the efficacy of prebiotics and probiotics on mental
health disorders,” says University of Chicago microbial ecologist
Jack Gilbert. “There needs to be a revolution in how we deal with
mental illness in our society.”
Source: www.the-scientist.com
ONLINE REPORTS
Yale scientists have developed a new class of small
molecules that attack fungal cell wall of pathogenic fungi and
signaling antibodies to join the process. The discovery offers a
potential new therapeutic approach to treat fungal illnesses that
affect thousands of people each year, including patients whose
immune systems are compromised by organ transplants, cancer
treatment and HIV infections.
The new compounds are called antibody-recruiting
molecules targeting fungi (ARM-Fs). These small molecules
have two main features: a target-binding terminus that latches
onto the fungal cell wall and an antibody-binding terminus that
recognizes and recruits antibodies already present in the human
bloodstream. Using the human immune system as the effector
arm this strategy was found to be incredibly versatile said Yale
chemistry and pharmacology professor David Spiegel and senior
author of the study describing the discovery in the German
science journal Angewandte Chemie. This is the first time they
have shown this strategy to work in treating a fungal disease.
Over the past decade, Spiegel's lab has explored small-
molecule approaches in treating a range of diseases, including
cancer and HIV. Spiegel said that not only are such molecules
effective against drug-resistant strains of diseases but also may
be used in combination with existing treatments.
Fig. The design showing antifungal antibody-recruiting small
molecules (ARM-F) targeting chitin, a fibrous substance in the
cell walls of fungi.
Image credit: Yale University
Source: www.sciencedaily.com
In a step toward bridging the gap between fungal
taxonomy and molecular ecology, scientists have characterized
a sample of mystery fungus collected in North Carolina and
found its home in the fungal tree of life.
"Working estimates tell us that there should be more than
5 million species of fungi," said Cheryl Kuske, a Los Alamos
scientist on the project. They have identified and fully
described 100,000 of them, though new DNA sequencing
capabilities showed that many specimens in their research
collections are uncharacterized. Solving this particular mystery
would reveal the potential value of using environmental
sequencing to guide taxonomic and ecological discovery.
The fungal sample was interesting as it partly represented
a major component of the observed fungal population in a pine
forest and it responded positively to elevated CO2 and nitrogen
amendment treatments that mimic future environmental
conditions yet the sample's exact placement in the taxonomic
order was unknown. The sample was eventually given a new
name, Bifiguratus adelaidae as reported recently in the journal
Mycologia.
Why was this hard? In times when a simple cheek swab
mailed off with a check can produce a human DNA report
listing thousands of ancestors, a sample identification would
seem a simple task. But as an editorial in the journal pointed
out, this sample represented one of many dark matter fungi that
populate unknown regions of the fungal tree of life. We can
detect their DNA in environmental samples, but their culture
has been elusive.
As noted in the journal's editorial, "This placement is
particularly exciting because of the increased understanding of
the mycorrhizal role (ability to form symbiotic, nutrient-
transfer relationships) for this part of the phylogeny and the
fact that very little is known about the species diversity and
distribution in this part of the tree. Bifiguratus adelaidae may
have a symbiotic function in roots, having been detected in 9
Storming the cellular barricades
to fight fungi
Hunt is over for one of the 'top 50
most-wanted fungi'
orchid and chestnut roots, but it is also well-documented in soils
from north temperate zones."
Interestingly, the collected sample had been cultured
successfully in the laboratory only when it was allowed to grow
in the company of a species of bacteria, Methylobacterium,
which antibiotics were unable to kill. Normally the fungal sample
would have been cleared of such contaminants, but this one
resisted their attempts. The authors posit that the symbiotic or
commensal microbes presence may be part of the culturing
success. Understanding complex microbial and fungal
communities is progressing, Kuske noted, by allowing organisms
to grow as defined mixtures.
The Bifiguratus adelaidae was named in honor of Adelaida
Chaverri Polini. Dr. Chaverri was a world-recognized tropical
biologist and role model for women in Latin America in science,
technology, engineering, and mathematics. Her major
contributions were in the study and conservation of tropical
montane forests and treeless alpine grasslands (páramos). As a
biologist, she recognized the importance of mycorrhizal fungi
and contributed to the description of a fungus in the
Acaulosporaceae, a fungus in the same phylum as the species
described in this paper. She supported the creation of Costa
Rica's National Park Service, providing the basis for extensive
conservation of biological diversity. In 2013, she was included in
the Galería de la Mujer, one of the highest honors given to Costa
Rican women for their dedication to defending and improving
women human rights.
Fig. Researchers at Los Alamos National Laboratory and several
other institutions have characterized a sample of mystery fungus
and found its home in the fungal tree of life. The fungus's exact
placement among the taxonomic order was unknown until now.
Los Alamos National Laboratory conducts a wide range of
biological research efforts as part of its national security science
mission, with such research as phylogenetic analysis helping to
determine safe pathogens and disease transmission pathways.
Image credit: Los Alamos National Laboratory
Source: www.sciencedaily.com
10
Peroxisomes identified as 'fighters' in
the battle against bacterial infections
A new addition to the fight against bacteria comes in
the unlikely form of an organelle that previously had no link
to the immune response. University of Alberta researchers
have found that peroxisomes are required for the cells in the
innate immune response against bacteria and fungi. The
discovery was first made in fruit flies. Research Associate
Francesca Di Cara, together with Richard Rachubinski,
Professor and Chair of the Department of Cell Biology and
Andrew Simmonds, Cell Biology Associate Professor,
partnered to create fruit flies that could be used specifically
for studying peroxisomal disorders, which are rare genetic
diseases affecting humans.
Di Cara found that peroxisomes are necessary for
proper functioning of the innate immune system, the body's
first line of defense against microorganisms. The innate
immune system is an ancient system of immunity that
identifies, captures and processes a pathogen and then
presents it to the acquired immune system. The peroxisomes
also communicate to other organs that there is an infection.
The team discovered that when the organelle's basic
function is altered, this communication is lost and the
organism does not fight the bacteria.
"Understanding how the body fights infection has an
impact on human health," says Di Cara. "We have to
understand who the fighters in the organism are before we
can identify what's failing in the battle against bacterial
infections.“
Peroxisomes are chemical factories that process
complex fat molecules into simple forms and modify
reactive oxygen molecules, which together act to signal cells
and tissues to respond appropriately for the changes in their
environment. Along with their collaborator Nancy
Braverman from McGill University, the researchers used a
mouse model to confirm that what they observed in the flies
also occurred in a mammalian system.
"To find organelles like peroxisomes that had no link
whatsoever to fighting bacterial infections was a critical
discovery, it will help expand the roles of what this
important organelle does in innate immunity against
bacterial and fungi and its involvement in viral signaling and
the lethal peroxisome genetic diseases," says Rachubinski.
As the threat of bacterial infections continues to grow, this
discovery can help move our understanding of immunity
forward.
Source: www.sciencedaily.com
research. This new finding proposes that they may be key
players in this globally vast realm. Studies of subterranean life-
forms have implications for early life on our planet and for life
on other planets, where hostile conditions may have inhibited
colonization of the surface.
Source: www.sciencedaily.com
Radioactive contamination is the unwanted presence of
radioactive substances in the environment. Our environment is
contaminated by naturally-occurring and anthropogenic
radionuclides, unstable isotopes of an element that releases
radiation and as it decomposes it becomes more stable which
are present in the air, soil, rain, etc. These radionuclides can be
transferred throughout the food chain until reaching humans
and this could lead for a potential health risk.
Until now, to study the presence of radionuclides in
different products for human consumption and their subsequent
transfer, research has been based fundamentally on foods such
as meats, fish or milk, without considering a foodstuff like
fungi which are well known for accumulating concentrations of
some radionuclides in their fruiting bodies. As a result, the
Environmental Radioactivity Laboratory of the University of
Extremadura (LARUEX) had carried out a study to quantify
radioactive presence in this foodstuff. The author of the study
Javier Guillén explained that the quantification was made using
transfer coefficients that compare the radioactive content in the
receptor compartment of the radioactive contamination (that is
to say in the fungi) to that existing in the transmitter
compartment (which in this case would be the soil).
To conduct this research the authors considered the base
level of radionuclides established in ecosystems with low
radioactive content and then used the software called the
ERICA Tool which allows one to enter the transfer coefficient
from the soil to the organism thus calculating the dose of
radionuclides a non-human organism receives.
From the study, it may be concluded that the estimated
dose rates for fungi are similar to those determined for other
animals (animals and plants) and therefore this species can be
used when assessing for the presence or absence of radioactive
contamination in the soil. As a result, the researcher asserted
that even though it is not strictly necessary to include
11
NEWS
In addition to the life on the surface of the Earth and in
its oceans, ecosystems have evolved deep under the earth
coined by the term “deep biosphere” which stretches several
kilometers down into the bedrock. The conditions are harsh
without oxygen and other favorable conditions present in the
earth surface. The knowledge about ancient life in this deep
environment is extremely scarce and most studies so far have
focused on the prokaryotes. A new study by an international
team of researchers led by Dr. Henrik Drake of the Linnaeus
University and Dr. Magnus Ivarsson of the Swedish Museum
of Natural History sheds light on eukaryotes in this deep
setting. They present the first in situ finding of fungi at great
depth in the bedrock. This ancient life is found at 740 m
below the ground surface. It represents a new piece in the
deep biosphere puzzle.
Henrik Drake, lead author of the study discovered the
fungi in a cavity hidden within a vein in a drill core he was
examining. They were beautiful like mineral crystals and
abundant in mycelium of fungal hyphae. To him it was like
observing a small community frozen in time.
Magnus Ivarsson another author explained more about
the fungi. Their detailed synchrotron-based investigations
clearly proved that it is fungi adapted to anaerobic conditions.
The fungi are partly mineralized and partly organically
preserved, which a rare find is revealing how organisms in
that environment are fossilized and preserved.
High spatial resolution isotope analysis within the
minerals that occur along with the fungi revealed that a
variety of microbial processes had occurred in the caveat,
including methane consumption and sulfate reduction. The
fungi could not be dated precisely but there are proxies
pointing to an age of tens of millions of years.
The study confirms a previously hypothesized
consortium between fungi and sulfate reducing bacteria, a
coupling that has yet been unsupported by direct evidence in
nature. As fungi provide hydrogen gas that fuel prokaryotes,
the findings suggest a re-evaluation of the energy cycling
within the energy-poor deep continental biosphere.
Eukaryotes have been neglected in the deep biosphere
Fungi are key players of the deep
biosphere
Fungi can be used as biomonitors
for assessing radioactivity in our
environment
fungi amongst the existing instruments and frameworks of
assessment, they can be used in ecosystems which may require
them based on criteria such as biodiversity.
Moreover, in the cases of the fungi analyzed, which are
concentrated in the Mediterranean area it should also highlight
the fact that they do not contain a high dose of radionuclides,
meaning there is no environmental contamination and they are
therefore perfectly suitable for consumption by humans.
Fig. Fungi can be used when assessing the presence or absence
of radioactive contamination in the soil.
Image Credit: Uex
Source: www.sciencedaily.com
01Applied Soil Ecology, 2017
Biochar chemistry defined by 13C-CPMAS NMR
explains opposite effects on soilborne microbes and crop
plants.
GiulianoBonanomi, Francesca Ippolito, Gaspare Cesarano,
Francesco Vinale, Nadia Lombardi, Antonio Crasto, Sheridan
L.Woob, Felice Scala.
Department of Agricultural Sciences, University of Naples
Federico II, Via Università 100, 80055, Portici, NA, Italy.
Numerous recent studies have demonstrated that biochar
may significantly reduce the incidence of plant diseases caused
by airborne and soilborne pathogens, although contrasting
results have also been reported. In this work, we investigated
how biochar affects crop plant and soilborne microbe growth.
Aims of this study were: i) to analyze the chemical changes
occurring in four organic feedstocks (e.g. wood chips, organic
urban waste, Zea mays residues, and Medicago sativa hay)
when pyrolyzed at 300 °C and 550 °C by using 13C NMR
spectroscopy and SEM (Scanning Electron Microscopy); ii) to
assess how biochar affects growth of five bacteria, nine fungi,
and three crop plants; and iii) clarify the relationships
between biochar chemistry and its effect on target species.
As pyrolyzation temperature increased, organic matter
chemistry of all products changed significantly, with a
progressive loss of O-alkyl C, di-O-alkyl C, and methoxyl
and N-alkyl C, coupled with an enrichment in aromatic C
types. Untreated urban waste and Medicago hay severely
inhibited Lepidium, Lactuca and Solanum root growth,
whereas no inhibitory effects were found for the other
feedstocks. However, these phytotoxic effects largely
decreased after pyrolyzation. In contrast to the crop plants,
fungi and bacteria thrive on most of the unprocessed organic
materials but showed reduced growth and development or
complete growth inhibition on biochars obtained at 300 °C
and 550 °C. Soilborne microbes demonstrated remarkably
similar correlation patterns between their growth to the
organic feedstock and biochar chemical components. This
work demonstrates that defining organic matter quality by
13C NMR extends our understanding of the impact of biochar
on crop plants and key components of the soil food-web.
Keywords: Beneficial microbes; C/N and H/C ratios;
13C CPMAS NMR; Disease suppression; Organic
amendment; Phytotoxicity; Rhizoctonia solani; Soilborne
pathogens.
12
Abstract of Recent Publications
NATIONAL
Cental Institute of Freshwater Aquaculture (CIFA)
http://cifa.nic.in
Patent facilitating centre for microorganisms
http://www.pfc.org.in/ach/micro.htm
National Centre for Biological Sciences
https://www.ncbs.res.in
National Collection of Industrial Microorganisms
http://www.ncl-india.org/ncim
INTERNATIONAL
American Society for Microbiology
https://www.asm.org
Center for Microbial Ecology
http://www.cme.msu.edu
International Society for Molecular Plant-Microbe Interactions
https://www.ismpmi.org/Pages/default.aspx
Japan Collection of Microorganisms (JCM)
http://jcm.brc.riken.jp/en/
E - Resources
EVENTS
Conferences / Seminars / Meetings 2017-18
4th International Conference on Microbial Diversity 2017. October 24 - 26, 2017. Venue: Bari, ITALY. Website:
https://www.md2017.it/about/
International Society for Subsurface Microbiology (ISSM) 2017. November 06 - 10, 2017. Venue: Rotorua, New
Zealand. Website: http://www.subsurfacemicrobiology.com
SMi's Pharmaceutical Microbiology East Coast Conference. November 13 - 14, 2017. Venue: Iselin, NJ, USA.
Website: https://www.smi-online.co.uk/pharmaceuticals/northamerica/conference/Pharmaceutical-Microbiology-East-
Coast
International Conference on Fungal & Infectious Diseases. December 04 - 05, 2017. Venue: Dubai, UAE.
Website: https://fungalinfections.conferenceseries.com
Pharmaceutical Microbiology UK. January 22 - 23, 2018. Venue: London, UK. Website: https://www.smi-
online.co.uk/pharmaceuticals/uk/pharmaceutical-microbiology
Pause to read the traffic sign: Regulation of DNA transcription in bacteria
Source: www.Phys.org
One of the central tenets of biology is that information flows from DNA to RNA in order to encode proteins,
which function in the cell. Arguably just as critical as the genetic code is the timing of this information flow. By
producing the right RNA and right proteins at the right time, a cell can effectively strategize its survival and
success. One such regulatory element, the riboswitch, has excited interest as a potential target for antibiotics. After
over 10 years of research, Scientists of Goethe University together with colleagues from other universities have
put together the puzzle pieces of a riboswitch-based regulatory process in the bacterium Bacillus subtilis,
presenting the most extensive model of the timing of riboswitch action to date.
A riboswitch is a short piece of RNA that can fold into different
structures, depending on whether or not a small messenger molecule is
binds to it. In transcriptional riboswitches, these different structures
signal the nearby RNA polymerase to continue producing RNA or to
stop. In their recent publication in ELife, the Schwalbe group and their
collaborators released molecular structures of the xpt-pbuX riboswitch
in the off-position after synthesis and in the on-position upon binding by
the small messenger molecule guanine. They also demonstrated that this
switch to the on-position takes a certain amount of time. This sets a
certain requirement on this regulatory process.
World Ozone Day Celebrations – Workshop on “Caring for all
under the sun” held on September 16, 2017.
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