Microbiology Lab Bio 231 اﻷﺣﯾﺎء اﻟدﻗﯾﻘﺔ اﻟﺟزء اﻟﻌﻣﻟﻲ

Home , Inoculation needle

المملكة العربية السعودية Kingdom of Saudi Arabia Ministry of Higher Education وزارة التعليم العالي KING ABDULAZIZ جامعة الملك عبد العزيزUNIVERSITY Supervised فرع كلية العلوم للبنات Faculty of Sciences قسم األحياء Dept. of Biological Sciences

Microbiology Lab Bio 231

األحياء الدقيقة الجزء العملي

إعداد: إشراف: أ.االء النهاري أ.د. رقية قشقري أ.أهله جمال د.هدى الشيخ أ.أروى زهيري د.منال قطان

Weeks # Date The Subjects

 Introduction to Microbiology 1 11-2-2013 28-3-1434  Health and Safety in microbiology laboratories

 Controlling of Microbial 18-2-2013 2 Growth 8-4-1434  Microbial Culture Media

Bacterial isolation and purification 25-2-2013 3 techniques 15-4-1434

 Bacterial Morphology 4-3-2013 4  Staining and Description 22-4-1434  Simple Stain

5 11-3-2013 29-4-1434 Gram Stain The quantitative measurement of 6 18-3-2013 6-5-1434 bacterial growth

7 Holiday

8 1-4-2013 Introduction to Mycology 20-5-1434 8-4-2013 9 Introduction to phycology 27-5-1434

15-4-2013 10 Introduction to Protozoa 5-6-1434

Introduction to virology and Immunology 11 22-4-2013 12-4-1434 29-4-2013 12 Revision 19-4-1434

Lecture 1

INTRODUCTION TO MICROBIOLOGY

 Microbiology is the study of living organisms of microscopic size, which include bacteria, fungi, algae and protozoa and the infectious agents at the borderline of life that are called viruses.

 It is concerned with their form, structure, reproduction, physiology ,metabolism and classification. It includes the study of their distribution in nature, their relationship to each other and other living organisms, their effects on human beings and on other animals and plants, their abilities to make

physical and chemical changes in our environment and their reactions to physical and chemical agents.

Health and Safety in microbiology laboratories األمن والسالمة في مختبرات االحياء الدقيقة

Dont Do

• Wear lab coat. • Do not play in the laboratory. • Wear gloves. • Do not use any laboratory. • Tie long hair neatly at the back of equipment until you are told to do the neck so. • Wear shoes that enclose your entire • Do not perform any laboratory feet. procedure until you are told to do • Wash your hands with disinfectant so. soap when you arrive at the lab and • Do not bring food or drinks into the again before you leave. laboratory. • Disinfect work areas before and • do not take cultures out of the after use laboratory. • Label everything clearly. • Never pipette by mouth. • Inoculating loops and needles should be flame sterilized in a Bunsen burner before you lay them down. • Sterilize equipment and materials. • Dispose of all solid waste material in a biohazard bag and container.

Laboratory Safety Signs

Instruments and tools used in microbiology laboratories االجهزة واالدوات المستخدمة في معامل االحياء الدقيقة

Compound Microscope .1

 أول من صنع المجاهر هو العالم الهولندي Antonyvan Leuwenhoek فان لوفينهوك عام )1632( والذي اخترع المجهر البسيط والمكون من عدسة واحدة.

 المجهر المركب من اهم المجاهر المستخدمة في الفحص االولي في معمل االحياء الدقيقة.

 السبب في تسمية هذه المجاهر بالمجاهر المركبة الحتوائها على عدستي تكبير أحداهما موجودة في العدسة العينية Ocular Lenses والثانية موجودة في العدسة الشيئية .Objective Lenses

اجزاء المجهر الضوئي المركب Parts and Uses of Compound Microscope

Part Functions

eyepiece lens Ocular A series of lenses that magnify 10 times.

Body tube Raised and lowered in focusing

Base supports entire microscope

Arm supports upper half of microscope

Objective Lenses Usually four magnifications: 4x lower power, 10x low power, 40x high power and 100x oil immersion.

Revolving Nose Piece can be rotated to change from one objective to another

Stage Support the mechanical stage and microscopic slides.

Iris diaphragm Control the amount of light striking the object

Condenser Condenses the light waves

Coarse adjustment moves body tube up and down rapidly for propose of approximate focusing

Fine adjustment moves body tube up and very slowly for propose of definitive focusing

Parts of Compound Microscope

Safety Cabinet .2 غرف عزل الميكروبات المجهزة بنظام دفع الهواء واالشعة الفوق بنفسجية لتحد من عملية التلوث او االصابة خالل عزل الميكروبات الممرضه. Autoclave .3 جهاز للتعقيم ويتم فيه التسخين بواسطة الضغط. Hot air oven .4 األفران التي تسمح بتسخين الهواء إلى درجات حرارة مختلفة وعادة ما يستخدم هذا الجهاز في تعقيم األدوات التي ال تتأثر بالحرارة العالية مثل الزجاجيات بأنواعها. Incubator .5 جهاز يستخدم لتحضين الميكروبات في درجات حرارة مناسبة , حيث يحتوي على جدار عازل يوفر منطقة معقمة ومعزولة لتنمية الميكروبات مع القدرة على التحكم في درجة الحرارة, غالبا ما يحتوي على باب خارجي بداخله باب اخر زجاجي يسمح بمراقبة نمو الميكروبات داخل البيئات بدون تلوثها. Water bath .6 الحمام المائي يستخدم للتسخين الغير مباشر باستخدام الماء, يستخدم عادة في اذابة البيئات واجراء التفاعالت المختلفة. Centrifuge .7 جهاز الطرد المركزي يستخدم لفصل العينات المختلفة اعتمادا على سرعة الدوران واختالف تراكيز وكثافة المواد, وتختلف انواعه وأشكاله وأحجامه. Balance .8 و يستخدم لقياس كتلة المواد المختلفة وله أشكال مختلفة فمنها ما يقيس لرقمين عشريين وهو األكثر شيوعا ومنها ما يصل لقراءة خمس أرقام وأكثر. Inoculation loop or Inoculation needle .9 ادوات التلقيح تختلف انواعها وأشكالها حسب استخداماتها. بعضها لالستخدام المتكرر ويمكن تعقيمها وبعضها االخر يستخدم مره واحدة فقط ويتم التخلص منها. Petri-dishes .01 طبق بتري عبارة عن وعاء مسطح دائري الشكل وشفاف مع غطاء، يصنع اما من الزجاج او البالستيك، لها اغراض مختلفة ولكن اهمها تستخدم كأوعية للبيئات التي تستخدم لتنمية الميكروبات. Glass Ware .11 مختلفة االشكال ومتعددة االستخدامات

Some Glassware Used in Microbiology Lab

Pipettes .12 الماصات متعددة االشكال واالستخدامات واالحجام, منها الزجاجية او البالستيكية, متكررة االستخدام او التي تستخدم لمرة واحدة فقط. Slides and cover slips .11 الشرائح واغطيتها الزجاجية تستخدم لفحص العينات بواسطة المجهر الضوئي Cork borers .11 الثاقب الفليني يستخدم غالبا لقطع دسك دائري من االنسجة والبيئات المختلفة Bunsen flame .11 اللهب

Lecture 2

Controlling of Microbial Growth

Methods of destroy, remove or inhibit the growth of microorganisms.

Definitions Sterilization:

The process to destroy all viable microbes (bacteria, viruses, fungi) including endospores. Sterilant: Material or method used to remove or kill all microbes. Disinfection: The process to destroy vegetative pathogens, not endospores and resistant organisms or bacterium spores.

 Disinfection Reducing the number of pathogenic microorganisms to the point where they no longer cause diseases.

Disinfectant: A substance or method used to kill microbes on surfaces. Antiseptic agents: Use of chemical agents on skin or living tissues to inhibit or eliminate microbes. Bacteriostatic Agent: An agent that inhibits the growth of bacteria, but does not necessarily kill them. Bactericide: An agent that kills bacteria (Most do not kill Endospores).

Microbial Control Methods

Physical Chemical Mechanical Methods Methods Methods

 Physical methods 1. Heat Sterilization: Heat sterilization is the most widely used and reliable method of sterilization, involving destruction of enzymes and other essential cell constituents

There are 2 procedures depending on the tolerance of the material used:

a) Dry heat  Dry oven: Time and Temperatures:

170⁰C for 1 hour or 160⁰C for 2 hours

Note:

Exposure time begins only after the sterilizer has reached the target temperature.

Do not overload the sterilizer.

Uses:

To sterilize Forceps, Scissors, Scalpels, Swabs.

Disadvantages:

Plastic and rubber items cannot be dry-heat sterilized because temperatures used (160–170 C) are too high for these materials.

 Flaming Holding Inoculation loop, Forceps and spatulas in a Bunsen flame till they are red hot.

b) Moist heat: • Temp below 100oC: Pasteurization

• Temperature at 100oC: Boiling.

• Steam under pressure: Autoclave. Uses:

• Serum or body fluids. • Liquids and Drinks • Media Autoclave: Autoclave works on the principle of Steam under pressure; it was invented by Charles Chamberland in 1879. Time and Temperatures: 121oC/10-40min Disadvantages: -Non stainless steel metal items corrode. -May damage plastic and rubber items.

2. Radiation: Two types of radiations are used

 NON –IONISING Electromagnetic rays with longer wavelength, Used in rapid mass sterilization of Syringes and catheters such as UV.

 IONISING High penetrative power rays, Used to Sterilize plastics Syringes, catheters, grease fabrics metal foils. Such as X- rays, gamma rays. Note:

No appreciable increase in the temperature – COLD STERILISATION

 Chemical Methods  The chemical compounds used can be: 1. Liquid Sterilization 2. Gas Sterilization

 Disadvantages: Generally, chemical sterilization procedures have the disadvantages of presenting health hazards to users (e.g. poisonous, flammable).

1. Liquid Sterilization  Alcohol: Act as surfactants dissolving membrane coagulating proteins of vegetative bacterial cells and fungi, Such as 70% aqueous solution of ethyl alcohol and isopropyl alcohol.

Uses

– Disinfection of clinical thermometer. – Disinfection of the skin and Venupuncture.

 Phenol: Phenol and phenolic compounds (e.g. lysol) lyse the cell membrane and denature proteins at 1-2% (aqueous solution). Uses:

– Various combinations are used in the control of pyogenic cocci in surgical & neonatal units in hospitals. – Aqueous solutions are used in treatment of wounds.

 ALDEHYDES: Formaldehyde is bactericidal, sporocidal & has a lethal effect on viruses.

Glutaraldehyde is effective against Tubercle bacilli, fungi and viruses

Uses:

To treat corrugated rubber anesthetic tubes, Face masks, Plastic endotracheal tubes, Metal instruments and polythene tubing.

2. Gas Sterilization:

Primary gas used in hospitals and clinics, such as Ethylene oxide and propylene oxide

Uses: Sterilize and disinfect plastics and prepackaged devices, foods.

Disadvantage:

Vapors are hazardous to people.

 Mechanical Methods:

Filtration:

Physical removal of microbes by passing a gas or liquid through filter, this process does not destroy but removes the microorganisms.

The pore size for filtering bacteria, yeasts, and fungi is in the range of 0.22- 0.45 mm

Uses:

Used to sterilize heat sensitive liquids and air in hospital isolation units and industrial clean rooms.

Microbial Culture Media

االوساط الزراعية لألحياء الدقيقة

Bacteria and other microbes have particular requirements for growth.

In order to successfully grow bacteria in lab, we must provide an environment suitable for growth.

Growth media (singular = medium):

Mixtures of nutrients that the microbes need to live, also provides a surface and the necessary moisture and pH to support microbial growth

Uses:

Media are used to cultivate microbial growth for the purpose of identifying and studying.

Classification of culture media Bacterial culture media can be classified based on

Nutritional Functional Consistency component use

 Based on consistency Culture media can be classified into:

1- Liquid media: Liquid media does not contain any solidifying agents. Liquid media are sometimes referred as “broths” (e.g. nutrient broth). Culturing in liquid medium can be used to obtain viable count (dilution methods). These media are available for use in test-tubes, bottles or flasks.

Nutrient broth media in test tube

2- Solid media: Containing 1-3% solidifying agent. Agar is the most commonly used solidifying agent, it is a polysaccharide derived from red algae, Agar also cannot metabolize by microbes. (e.g. nutrient Agar).

Nutrient Agar medium

3- Semi solid media: Containing 0.2-0.5% Solidifying agent, this media are useful in demonstrating bacterial motility and separating motile from non- motile strains.

 Based on nutritional composition, culture media can be classified as:

1. Simple media: Media that provide the minimal requirements for microbes to (e.g. Peptone water, nutrient agar).

2. Complex media: The complex media are Enriched media with that often prepared from very complex materials such as body fluids; tissue extracts (e.g. blood agar and Chocolate agar). The exact chemical composition is not known in complex media.

3. Chemically defined media (synthetic Media): If all the chemical composition of a culture medium is known, both qualitatively and quantitatively, the medium is called a chemically-defined medium. These media are use in studying the nutritional requirements of microorganisms or in studying their metabolic activities.

 Based on functional use culture media can be classified into:

1. Selective Media: Selective medium supports the growth of desired organisms while inhibiting the growth of other organisms which may be commensals or contaminants. This is accomplished by adding one or more selective agents that inhibit the unwanted organisms or by adding certain specific nutrients to support the growth of the required organism. This medium helps in isolating the desired organism from a mixed culture.  For example: - Eosin methylene blue (EMB) that contains methylene blue – toxic to Gram-positive bacteria, allowing only the growth of Gram negative bacteria. - MacConkey agar for Gram-negative bacteria

2. Differential media: Differential media are used to differentiate between two or more types of organisms based on their colony characteristics and color. This medium is done by incorporating certain dyes or other components which are utilized by different bacteria to produce a variety of end products or effects.

 For example: - Eosin methylene blue (EMB), which is differential for lactose and sucrose fermentation. - MacConkey (MCK), which is differential for lactose fermentation

MCK Agar EMB Agar

The main microbial growth media used in the laboratory:

- Nutrient Agar medium: Nutrient agar is commonly used for the routine cultivation of bacteria and it is a base of other selective and enriched media. It consists of nutrient broth with 2-3% agar.

Agar plate

agar slant tubes

Agar tubes

- Potato Dextrose Broth and agar (PDA:

Used for the cultivation of yeasts and molds especially Fusarium specie

Preparation of microbial media تحضير البيئات الميكروبية The basic requirements in microbial media preparation:

 Energy source - Carbon source - Nitrogen source Mineral salts.  PH (PH= 6-7 for most Fungi, PH= 7-8 for most bacteria). PH meter can be used to adjust pH in media.

 Sterilization (media are sterilized by autoclaving at 1210C and 2 atmosphere for 15-20 minutes).  The ratio of oxygen and moisture (Depend on the type of microbes).

The Materials:

1000ml distilled water – peptone - measuring cylinder – Agar as a powder – Balance – Water bath - HCl or NaOH – PH meter – Autoclave - Petri-dish – Bunsen Flame – cotton - beef extract.

The procedure:

1- Dissolve the weighed amounts of peptone (10g) and beef extract (3g) into 1000 ml of water. 2- Weigh 20g agar and add to the mixture. 3- Adjust the pH of medium to 7 by adding 2 drops of HCl or NaOH. 4- Heat and dissolve the mixture by using a water bath (100 0C).

5- Dispense the mixture into conical flasks and Plug the flask with cotton. 6- Sterilize the mixture by Autoclave at 1210C for 15-20 minutes. 7- Allow the cooker to cool by putting the conical flask in water bath (450C) ?? (This is to prevent them from solidifying). 8- Prepare agar plates by pouring media (15-20ml) into Petri-dish under aseptic condition; allow the media with Petri-dish to solidify. 9- Incubate the Petri dishes in an inverted position?? at 37 C for 42h?? for examine any contamination.

Note:

 Pouring should be performed near the flame.

 Incubate the Petri dishes in an inverted position to prevent the condensation from dropping on the agar surface.  Storage of culture media is necessary by using domestic refrigerators?? (To prevent contaminated),  In order to prepare nutrient broth media you can follow the same

procedure except adding of agar?? and pouring in petri-dish.

POURING PLATES

Lecture 3

Bacterial isolation and purification techniques Bacteria are found almost everywhere on the planet from miles high in the atmosphere to miles below the surface of the planet. Different species of microbes can live together in some habitats. The human mouth, for example, is extremely rich in bacteria of many different genera.

Isolation of bacteria from different sources:

Materials: Nutrient agar medium. Cotton swap.

Method: 1) Isolate bacteria from different sources water, soil, air and mouth. 2) Use cotton swap to pick up the bacteria. 3) Open Petri dish and use the lid as a shield to prevent contamination. 4) Gently rub the swab in a zigzag pattern across the agar. 5) Replace lid and dispose the cotton swap.

6) Label the base of the plate with your name, date, and sample.

7) Incubate plate upside down for the 48 hours 37oC.

8) On your next class you will observe the diversity of types and morphology of colonies and record it.

Methods of isolation of pure culture

 Isolation of a pure culture is to insure the growth of a single strain, free from mixture and contamination with other bacteria.  It is important in all bacteriological studies.  Usually solid medium poured in plates is used to isolate pure culture to ensure the growth of separated colonies far from each other.  The main purpose of pure cultures is to isolate individual bacterial cells (colony-forming units) on the medium.

Techniques of isolation pure culture:

1) Streak plate 2) Spread plate methods: method:

a) Zigzag streaking (simple streaking)

b) Quadran streaking (continuous)

Techniques of isolation pure culture:

1) Streak plate methods:

In this method we streak the bacteria over the surface of plated agar medium. The density of the cells will gradually decrease until single cells will be placed on agar surface at the end of streaking. And each single cell will form a colony.

Material:

Mixed bacterial Cultures - Nutrient agar plates - Inoculating loop or cotton swap. a) Zigzag streaking (simple streaking): Method:

1- Obtain sample of mixed culture with a sterile loop or cotton swap.

2- Hold the loop or cotton swap comfortably in one hand and lift the lid of the Petri dish with the other hand. Use the lid as shield to protect from airborne bacteria.

3- Lightly drag the cotton swap on agar surface in a zigzag pattern. Be careful not to cut agar surface.

4- Replace the lid and dispose the swap.

29 b) Quadrant streaking (continuous):

Method:

1- Flame your loop, let it cool, and then remove one colony from the mixed culture.

2- Hold the loop comfortably in one hand and lift the lid of the Petri dish with the other hand. Use the lid as shield to protect from airborne bacteria.

3- Start at the edge of the plate and lightly drag the loop back and forth across the agar surface as shown in the figure. Be careful not to cut agar surface.

4- Flame your loop and let it cool then rotate the plate and cool the loop by touching a clear part on the agar.

5- Do another streaking by the sterile loop starting from the end of the first streak as shown in the figure.

6- Flame your loop and let it cool then repeat with a third streak staring fron the second streak and extend it to the center of the plate.

Note

After you finish streaking remembers to …

1- Replace the lid and flame the loop

2- Label the base of the plate with your name, date,

and sample. 3- Incubate plate upside down for the assigned time and temperature.

Which plate gave the best isolation according to your results?

1 2

Lecture 4

Bacterial Morphology

Staining and Description

Bacteria cannot be visualized by naked eye, to understand their morphology it becomes necessary to make them more easily visible.

 Basic techniques to Study bacterial morphology:

1. Studying of Bacterial Colony Morphology: ]

2. Bacterial Staining:

A procedure in which colored chemicals called dyes are added to bacterial film. Dyes color the cells or cell parts by becoming affixed to them through a chemical reaction.

 The Basic types of staining

 Simple Stain: By using a single dye.

 Allows determining cell shape and arrangement under a microscope.  Can be done with methylene blue, safranin and crystal violet.

 Differential Stain: By using two or more dyes.

 Allows differentiating between bacteria close to each other and between the different parts of bacterial cells.

Examples: Gram Stains and Ziel-Neelsen Acid-Fast Stain.

Preparation of Bacterial smear And Simple Stain Procedure:

 Preparation of Bacterial smear:

To go for staining procedure the first thing you should have to do, is to prepare a thin bacterial film.

In order To prepare bacterial smear from broth medium follow the following steps:

2 - 1- Sterilize the

loop and then allow to cool in air.

Note: In solid media just place small water drop on the middle of the slide then spread the culture.

 Simple Stain Procedure:

2- Cover the 4- Use paper towel smear with the to remove excess 1- preaper stain. water then let it air Bacterial 3- Let the stain sit dry. smear. for 1 minute then 5- View your slide Rinse till the under oil water runs clear. immersion lens.

3. Microscopic Examinations: The procedure:

1. Place the slide on the stage and Switch the lamp on. 2. Rotate the revolving nose until the x100. 3. Carefully place large drop of immerse oil on the Smear. 4. Use the Coarse adjustment immerses the objective into the oil while looking from the side. 5. Gently lower the objective until the slide contact has been made. 6. Looking through the ocular and slowly turn the coarse adjustment back until the object comes into focus. 7. Use the fine adjustment for definitive focus.

 Common Shapes and Arrangement of bacterial cells:

Observations and results:

Description of Cell The name of plate # Description of Colony Shape Bacteria

Lecture 5

Bacterial Morphology

Staining and Description  Gram stain  The most important differential stain used for diagnostic identification of bacteria, its developed by Christian Gram in 1884.  By this stain bacteria can be divided into two large groups of bacteria Based on their different cell wall constituents.

Gram Stain

Gram positive

bacteria stain violet due to the presence of a thick layer of peptidoglycan in their cell walls.

Gram negative bacteria stain red, due to a thinner peptidoglycan layer in cell wall.

Gram staining consists of four components:

 Primary stain (Crystal violet).

 Mordant (Gram's Iodine):

Crystal violet binds to the iodine mordant causing this large molecule to become trapped in the layers of peptidoglycan of Gram+ cells.

 Decolourizer (95% alcohol):

Does not remove the crystal-violet stain trapped within the Gram- positive cell wall, but does remove the stain from the thin layer of peptidoglycan of Gram-negative bacteria.

 Counter stain (safranin):

Imparts pink color to the colorless Gram- bacteria, but doesn't change the color of Gram+ cells.

Observations and results:

Cells Gram’s Bacterial Cells Shape Cells Color Arrangement reaction name

Gram staining procedure:

Lecture 6

Introduction to Mycology

 The study of fungi is called mycology, and fungal diseases are called mycoses.  The fungi (singular, fungus) include several thousand species of eukaryotic.

Fungal Structure and Morphology Fungi can be divided into two basic morphological forms

Molds Yeast Filamentous fungi consist of Microscopic, unicellular long, branching filaments of cells called hyphae fungi with a single nucleus (singular, hypha). and eukaryotic organelles. A mass of hyphal elements is For example termed to mycelium (plural, Saccharomyces mycelia) For example, Penicillium, Aspergillus and Rhizopus.

hypha hypha

Vegetative septate (regular hyphae grow on crosswalls) or in media (absorb nutrients)

Aerial hyphae nonseptate contain structures (coenocytic) for production of spores

Note

 The mycelium can organize to form complex fruiting

bodies such as mushrooms.

 Some species of fungi have the ability to shift from the yeast form to the mold form and vice versa. These fungi are dimorphic.

 Many fungal pathogens exist in the body in the yeast form but revert to the mold form in the laboratory when cultiva ted.

Isolation and microscopic examination of Fungi

 Isolation of plant pathogenic fungi from diseased plant material: Materials:

Potato dextrose agar (PDA) medium, a sterile cork borer, inoculation needle, Plant samples showing infected tissue (tomato, orange), alcohol, Forceps, burner/spirit lamp, 1 % sodium hypochlorite solution

Procedure: 1. Select infected tissue and Cut into small pieces (2-5 mm) then and keep in sterile Petri dishes

2. Dip the pieces into 1 % sodium hypochlorite solution for about one minute then wash It by sterile water to free them from the chemicals

3. Lit the burner then near the flame Transfer the pieces in the center of PDA plate.

4. Incubate the Petri dishes at 25° C and examine for 3-5 days and observe the incubated plates from the second day onwards for the growth of the fungus.

 microscopic examination of Fungi:

Materials:

Compound microscope, slides and cover slips, dropper bottle with water, , inoculation needle.

Procedure:

Transfer small part from infected tissue and place it on a microscopic slide, add a drop of water and put cover slip and observe it under microscope.

Observations and results

Sample 1 Sample 2 The sample The color and description of the colonies in medium

Observations under

microscope

Lecture 7

Introduction to Algae

 Algae are usually photosynthetic and aquatic, but do not have true roots, stems, leaves, vascular tissue and have simple reproductive structures.

 They are distributed worldwide in the sea, in freshwater and in wastewater.

 Most are microscopic, but some are quite large, e.g. some marine seaweeds that can exceed 50 m in length.

 The study of Algae is called Phycology.

 Algae body called Thallus.

 Algae can be divided depending on the structure in to six types:

Unicellular Colonial algae Filamentous algae alga

Such as: Such as: Such as: Chlamydomonas Volvox Spirogyra

coenocytic Membraneous Parenchymatous algae algae algae

Such as: Such as: Such as:

Vaucheria Ulva Sargassum

Chlamydomonas

Volvox

Spirogyra

Vaucheria

Ulva

Sargassum

Lecture 8

Introduction to Protozoa

 Protozoa (proto – primitive; zoa – animal) are free-living organisms that inhabit water and soil. Some live in association with other organisms as parasites.  The study of Protozoa is called Protozoology.

 Characteristics of Protozoa are:

- Eukaryotic

- Single-celled (unicellular)

- No cell wall

- Motility (nearly all are able to move due to cilia, flagella and pseudopodia).

- Motile feeding stage called trophozoite and many have hardy resting stage called cyst.

Some organisms to be studied in lab:

 Amoeba Sp.

Amorphous structure changing shape due to formation of pseudopodia.

 Euglena Sp.

Elongated shape with flagella protruding out of one end; green due to presence of chloroplast.

 Paramecium Sp.

Slipper shaped cell with many cilia distributed over the entire surface of the organism.

References: 1. A Textbook of Microbiology, R.C. Dubey and D.K. Maheshwari, 2009 2. Manual of Practical Microbiology, Abla M. EL- Mishad, 2006. 3. Hand book of microbiology, P.S. Bise and Kavita Verma, 2004. 4. Microbiology in Practice, Samira Shoeb and Omer EL-Dali, 1986.

Study Hard & Good Luck 