實驗二十三

細菌 (Bacteria)

徐馨怡syshyu@ntu.edu.tw

Bacteria

Prokaryotes

Unicellular or associate in characteristic

patterns

ubiquitous, mostly free-living organisms

Reproduction: binary fission

Bacteria can be classified according to cell

shape, mode of nutrition, mode of respiration,

etc.

Fimbriae

Cell wall

Circular

chromosome

Sex pilus

Flagella

Internal organization

Capsule

Peptidoglycan

No nucleus

Movement

DNA transfer

No membrane-bound organelles

Attachment

Shape: cocci (spherical), bacilli (rod), spirilla (spiral)

Other structures

Endospore – dormant structure

Capsule – can be the cause of various diseases.

Flagella – movement

Sex pilus – DNA transfer

Fimbriae – attachment

The difference of the cell wall between G+ and G-bacteria

Gram stain

Antibiotic susceptibility test

Materials:

• Escherichia coli , G−

• Bacillus subtilis, G+

Method:

Dip the bacteria liquid with a sterile cotton swab

Spread the bacteria liquid evenly on the agar plate

Add the antibiotic discs

37℃ overnight

Record the result

Antibiotic disc:

• Penicillin

• Polymyxin B

• Streptomycin

Fume Hood:

protect the user from inhaling toxic gases

protect sample or experiment

protect the environment

Laminar Flow Cabinet

protect the sample from the user

Biological Safety Cabinets (BSCs)

Class I: provide personnel and environmental

protection but no sample protection

Class II: provide both kinds of protection (of the user,

samples and the environment)

Class III: only installed in maximum containment

laboratories, is specifically designed for work with

BSL-4 pathogenic agents, providing maximum

protection. It is a gas-tight enclosure with a non-

opening, completely sealed, viewing window.

Usage guideline for BSC

Preparing BSC for work

Turn off the UV light prior to starting work

Operate cabinet blowers at least 3-5

minutes before beginning work

Use 70% ethanol to clean work surface of

BSC

Working in the BSC

Minimize movement into and out of the

BSC

Work at least 10 cm from the inside edge

of the front vent

Bunsen burners, other continuous flame

devices are prohibited in biosafety

cabinets.

Finishing Work in the BSC

Clean the BSC after each use. Wipe the

interior surfaces with 70% ethanol.

Leave the fan blower on in the cabinet for

5-10 minutes after finishing work.

Bacteria report (group)

Penicillin Polymyxin B Streptomycin G+ or G- Species

A

B

Title

Results:

Photos of plates (mark the bacteria & antibiotic discs)

Measure the inhibition zone, and finish the table

Discussion:

Find out the mechanism of the 3 antibiotics and explain how to determine

the bacterial species.

Reference

Dept, group, members, the author

12 point, Times New Roman

Upload the pdf file to NTU COOL before 9pm on 12/7 (Wed)

Algae do not include a common ancestor

Most are phototrophic, some are

mixotrophic

Belong to 4 supergroups

實驗二十四、二十五

藻類 (Algae)

囊泡蟲類 原生藻菌類

有孔蟲類

古蟲類

後鞭毛生物

變形蟲類

Algal characteristics to classification

Photosynthetic pigments

Chemical nature of stored food materials

Chemical composition of cell wall

Number point of insertion and relative length of the flagella

Details of cell structure

Morphology

DNA sequences

Materials:

Blue-green algae (cyanobacteria)

藍鼓藻 (Gloeocapsa sp.)；色球藻 (Chroococcus sp.)

念珠藻 (Anabaena sp.)；顫藻 (Ocillatoria sp.)

Green algae

盤星藻 (Pediastrum sp.)；水綿 (Spirogyra sp.)

新月藻 (Closterium sp.)；鼓藻 (Cosmarium sp.)

Charophyta: 輪藻 (Chara sp.)

Euglenoids: 眼蟲 (Euglena sp.)

Diatoms:矽藻 (diatom)

Dinoflagellates: 角甲藻 (Ceratium sp.)；多甲藻

(Peridinium sp.)

Brown algae: 昆布 (Laminaria sp.)

Red algae: 石花菜 (Gelidium sp.)

Cyanophyta 藍綠菌

Prokaryotes, and have the peptidoglycan layer in their cell wall.

The cells are often enclosed in slime or gelatinous sheath.

Unicellular and colonial to filamentous forms. Flagella are not

formed at any stage of the life cycle.

Photosynthetic pigments: Chlorophyll a and various forms of

chlorophyll, carotenoid, phycobilin

exhibit functional cell differentiation such as heterocysts (for

nitrogen fixation), akinetes (resting stage cells).

Reproduction (unsexual): fission, fragmentation, exospore.

Chroococcus sp.色球藻

Gloeocapsa sp. 藍鼓藻Gelatinous sheath

Cell wall

• The shape, color of cells.

• Major characteristics？

• How to distinguish these 2 algae？

Microcystis via fmp.conncoll.edu

Microcystis sp. 微囊藻

M. Lorenz: 2016-08-18, CC BY 4.0,

via Wikimedia Commons

• The shape of cells and the filaments.

• The color and characteristics of the filament.

• Find heterocyst and akinete

Anabaena sp. 念珠藻(forms a symbiotic relationship with

the fern Azolla sp.)

Akinete

Heterocyst

Oscillatoria sp. 顫藻

Chlorophyta 綠藻

Green algae contain the same carotenoids and chlorophyll a

and b as land plants and store food as starch in their plastids.

Their cell walls are made of cellulose. Hence green algae have

a close relationship with land plants.

All members of the clade have motile flagellated swimming

cells.

They are diverse in structure and life history and are found in a

wide variety of habitats.

盤星藻Pediastrum sp.

Scenedesmus sp. 柵藻

Desmids 鼓藻類 (slide) Closterium sp. 新月藻Semi-cell

Cosmarium sp.

Micrasterias sp. Euastrum sp.

Xanthidium sp.

Spirogyra sp. 水綿 (slide)

• The shape of chloroplasts.

• The nucleus, vacuole, pyrenoid.

• The sexual reproduction

cytoplasm

strand of cytoplasm pyrenoid

cell wall

chloroplast vacuole

nucleus

(Zygote)

• Unsexual – fragmetaion

• Sexual – conjugation

Pyrenoid

Nucleus

Ulva sp. 石蓴

Charophyta 輪藻

Chara sp. 輪藻 (slide)

Charophyta contains chlorophyll a and b as

land plants and green algae. They store food

as starch and cell walls are made of cellulose

as well. Hence green algae have a close

relationship with land plants.

The charophytes and embryophytes share

several traits in certain enzymes, flagella, and

mitosis. Thus Charophyta and Embryophyta

together form the clade Streptophyta,

They superficially resemble land plants

because of stem-like and leaf-like structures.

Crown cell

Tube cell

1 egg cell

Appendage

cell

Oogonium

藏卵器

Antheridium

藏精器

Long flagellum

Eyespot

Short flagellum

Nucleus

Chloroplast

Plasma membranePellicle

Euglena (LM) 5 µm

Euglenophyta 裸藻

Autotrophic or heterotrophic

Photosynthetic pigment: chl a, chl b, carotenoids

Carbohydrate food reserve: paramylon

Morphology: no cell wall, have the stigma, have pellicle

(proteinaceous strips) underneath the cell membrane.

Euglena sp. 眼蟲

Main characteristics of cells

The movement

The stigma and flagella

Phacus sp. 扁眼蟲Euglena sp. 眼蟲Lepocinclis sp.

鱗孔藻

Bacillariophyta 矽藻

Photosynthetic pigment: chl a,

chl c, carotenoids, and

fucoxanthin.

Carbohydrate food reserve:

chrysolaminarin

Morphology: unicellular, non-

flagellate.

Their cell wall made of silica

(hydrated silicon dioxide),

called a frustule. The frustule

is made up of two, overlapping

half-shells termed the epitheca

and hypotheca.

兩側對稱矽藻Pennate diatoms

輻射對稱矽藻Centric diatoms

A. 輻射對稱矽藻(Centric diatoms)

B. 兩側對稱矽藻(Pennate diatoms)

A

B

Diatom 矽藻 (玻片)

Girdle band

Oil drop

Nucleus

Chloroplast

Epitheca

Hypotheca

腰帶面 Girdle view

腰帶面 Girdle view

殼面 Valve view

Girdle band

Dinophyta 渦鞭毛藻

Photosynthetic pigment: chl a, chl c,

carotenoids, and peridinin.

Carbohydrate food reserve: starch

Morphology: unicellular biflagellates,

with cellulose forming the theca.

A rapid accumulation of certain

dinoflagellates can result in a visible

coloration of the water, colloquially

known as red tide (a harmful algal

bloom).

The term “red tide” is somewhat

misleading. It is better to use the term

“Harmful algal blooms” (or HABs) to

present the phenomenon when

colonies of algae grow out of control

and produce toxic or harmful effects

on people, fish, shellfish, marine

mammals and birds.

groove

Ceratium sp. 角甲藻 (slide)

Peridinium sp. 多甲藻 (slide)

The various color of the red tides caused by sea sparkle (Noctiluca scintillans).

Phaeophyta 褐藻 Photosynthetic pigment: chl a, chl

c, carotenoids, and fucoxanthin.

Carbohydrate food reserve:

laminarin, mannitol

Morphology: are a large group of

multicellular algae and exist in a

wide range of sizes and forms.

Brown algae have specialized

structures of thallus, stipe, and

holdfast.

Brown algae are unique in

developing into multicellular forms

with differentiated tissues, but

they reproduce by means of

flagellated spores and gametes .

Fucus sp.

石衣藻

Sargassum sp. 馬尾藻

Laminaria sp. 昆布 (slide)

Blade

Stipe

Holdfast

ZoosporangiumParaphysis

Rhodophyta 紅藻

Photosynthetic pigment: chl a, phycobilin, carotenoids.

Carbohydrate food reserve: floridean starch

Morphology: unicellular, microscopic filaments, multicellular and no

flagella.

The cell walls of most red algae contain sulfated polygalactans which are

the major component of agar.

Porphyra sp. 紫菜

Gelidium sp. 石花菜

Cryptophyta 隱藻

Photosynthetic pigment: chl a, chl c, phycobilin,

carotenoids.

Carbohydrate food reserve: starch

Morphology: unicellular, two slightly unequal flagella.

Their chloroplasts have 4 surrounding membranes,

which indicate a secondary endosymbiosis.

Cryptomonas sp. (隱藻)

Homework (group)

Finish the form

Group report (photos with ocular micrometer)

Title

The photos

Fresh materials: scientific name, photographer, magnification

Water sample:

list (sample location, species, photographer)

photos: 6 species (or 3 species/sample); note the location,

scientific name, photographer, magnification.

Dept. group, members, author

Upload the pdf file to NTU COOL before 9pm on 12/7 (Wed)

Title

Photo assignments example

念珠藻 Anabaena sp.，王小明，400X

Fresh materials

Photo: Photos should be trimmed properly

the focus should be clear

appropriate magnification power

9 photos at most in 1 page

Figure legend: Below the photos

scientific name, photographer,

magnification.

Others: the proportion, position of the photos

Title and the list

The water smaple

水樣 中名 學名 拍攝者

生態池 眼蟲 Euglena sp. 王小明

xxx

xxx

醉月湖 xxx

Table 1: lists of algae

生態池

眼蟲 Euglena sp. ，王小明，400X 鼓藻 Cosmarium sp.

王小明，400X

多甲藻 Peridinium sp.

王小明，400X

Figure legend: Below the photos

scientific name, photographer,

magnification.

加分作業 Bonus assignment

找到 Paulinella sp. Find Paulinella sp.

拍照，非本人拍攝請列出拍攝者

Take pictures, please list the photographer

在葉綠體演化上有何意義

What is the significance of this species in the evolution

of chloroplasts?

pdf 檔於2022/1/5 (三)晚上9點前上傳完畢

Upload the pdf file before 9pm on 2022/1/5 (Wed)

Slide Fresh material Water Sample

Anabaena sp. (念珠藻) Gloeocapsa sp. (藍鼓藻) 生態池 綠藻

Spirogyra sp. (水綿) Chroococcus sp. (色球藻) 醉月湖 褐藻

Desmid (鼓藻) Anabaena sp. (念珠藻) 紅藻

Chara sp. (輪藻) Ocillatoria sp. (顫藻)

Diatom (矽藻) Spirogyra sp. (水綿)

Ceratium sp. (角甲藻) Chara sp. (輪藻)

Peridinium sp. (多甲藻)

Laminaria sp. (昆布)