© 2008, YCMOU. All Rights Reserved.1 Online Counseling Resource YCMOU ELearning Drive… School of Architecture, Science and Technology Yashwantrao Chavan

© 2008, YCMOU. All Rights Reserved. 1

Online Counseling ResourceYCMOU ELearning Drive…

School of Architecture, Science and TechnologyYashwantrao Chavan Maharashtra

Open University, Nashik – 422222, India


OC-SBT081-CP01-05

Introduction

Programmes and Courses SEP – SBT081 – Unit 01

School of Science and Technology, Online Counseling Resource…


Credits

Academic Inputs by Arun Punaji More.

M.Sc. (Microbiology) Experience: 11 Years [email protected]



How to Use This Resource

Counselor at each study center should use this presentation to deliver

lecture of 40-60 minutes during Face-To-Face counseling.

Discussion about students difficulties or tutorial with assignments should

follow the lecture for about 40-60 minutes.

Handouts (with 6 slides on each A4 size page) of this presentation should

be provided to each student.

Each student should discuss on the discussion forum all the terms which

could not be understood. This will improve his writing skills and enhance

knowledge level about topics, which shall be immensely useful for end

exam.

Appear several times, for all the Self-Tests, available for this course.

Student can use handouts for last minutes preparation just before end

exam.



Learning Objectives

After studying this module, you should be able to:

Describe characteristics of fungi.

Describe the characteristics of slime mould.

Describe the differentiating features of moulds and slime

mould.



Introduction-1 We have observed many a times breads with

fine green or black lawn fibrous growth of organism or spoiling of pickles by whitish fibrous growth of organisms on the surface layer of pickle.

Many times you might have enjoyed the delicious mushroom pulao and mushroom pizza that your mother have prepared for you.

By the time you finished reading the above sentence you might have guessed that the fibrous growth spoiling the pickles and breads and the mushroom in your pizza are nothing but members of fungi.

Let us see more interesting characteristics and their feats of fungi in more details.



Fungi-1 The members of fungi share many

common features with plant, animal cells and protozoa.

For example animal cells, plant cells and fungi are grouped as eukaryotic cells.

Like protozoa, fungi are chemoheterotrophic.

However the fungi differ from plant cells in that that the plant cells contain chlorophylls whereas the fungi do not contain chlorophylls.



Fungi-2 Many fungi are used as foods. For

example mushroom and truffles. Many fungi are used to prepare foods such

as breads, some cheese and beverages such as soy sauce, citric acid and alcoholic drinks.

Many fungi are utilized as research tools. For example the Saccharomyces

cerevisiae is used in genetic engineering to produce recombinant strains of this yeast to manufacture many human proteins and some viral vaccine such Hepatitis B vaccine.



Characteristics of Fungi-1 The kingdom fungi is classified under the

domain Eukarya. The members of fungi are eukaryotic cells. The fungi differ from animal cells in that

that they possess cell wall. The characteristic feature of fungi is that

their cell wall contain chitin, a nitrogenous complex polysaccharides.

Being heterotrophs, fungi play crucial role in the maintaining ecological balance by decomposing dead plant and animals recycling their nutrients.



Characteristics of Fungi-2 They differ from plant cells in that that they do

not possess chlorophyll pigments. The unicellular members of fungi differ from

prokaryotes in that that they lack peptidoglycan in their cell walls; but their cell wall contain chitin, a nitrogenous polysaccharide.

Some members of fungi are unicellular; whereas some members of fungi are multicellular present in mycelial forms.

Some members of fungi, for example, can be present in more that one forms; such fungi are called as dimorphic fungi.

Yeast is example of dimorphic fungi.



Characteristics of Fungi-3 Reproduction of Fungi:- Unicellular fungi reproduce by budding. Mycelial fungi reproduce asexual as well as

sexually by forming spores. Asexual spores depending upon their mode of

development are classified as follow: Sporangiospores:- developed inside the sac called

as sporagium. Chlamydospores:- developed inside the thick cell

of hypae. Conidiospore:- developed on the tip of hypae.

Types of conidiospores: Arthrospores – developed by fragmentation of hypae. Blastoconidia-- developed as buds on tips of hypae.



Characteristics of Fungi-4 Reproduction of Fungi:- Sexual spores formation occur when

positive and negative hypae fuse together forming dikaryon, cell containing two positive and negative nuclei.

In the dikaryon the positive and negative nuclei recombine to form a single diploid nucleus after some time.

The diploid cells then undergo meiosis forming haploid nuclei which are surrounded by cytoplasm forming spores.



Classification of Fungi-1 The fungi are divided into four divisions.

Zygomycota Ascomycota Basidiomycota Deuteromycetes

The first three divisions are on the basis types of sexual spores produced by the fungi; whereas the fourth division has no known sexual stage.



Classification of Fungi-2 Zygomycota:-

Example of zygomycota is black bread molds such as Rhizopus and Nigricans.

The members of zygomycota reproduce by sexual as well as asexual mode.

In asexual mode of reproduction, asexual spores are produced called as sporangiospores.

In sexual mode of reproduction, sexual spores are produced called as zygospores.



Classification of Fungi-3 Ascomycota:-

Examples of ascomycota are penicillium which produces antibiotic called as penicillin and saccharomyces which produces alcohols from sugars.

Truffle, the edible underground mushroom and pink bread molds, Neurospora are another examples of ascomycota.

The Neurospora is used as genetic tool in genetic engineering technology.

The members of ascomycota fungi produce sexual spores in sac called as asci.



Classification of Fungi-4 Following figure show budding yeasts of

saccharomyces.

Fig: saccharomyces



Classification of Fungi-5 Aspergillus, One of the member of

ascomycota produce conidiospores on the tip of hypae as shown below.

Fig: Conidiospores of Aspergillus



Classification of Fungi-6 Basidiomycota:-

The edible and poisonous mushrooms are member of basidiomycota.

Cryptococcus neoformans, the important fungal species pathogenic to humans, is also one of the members of basidiomycota.

The basidiomycetes fungi reproduce by producing sexual spores called as basidiospores.



Classification of Fungi-7 Deuteromycetes:-

The sexual stage of these fungi is unknown. However the rRNA analysis of these fungi

shows that they are genetically similar to the members of ascomycota.

Trichophyton, one of the members of deuteromycetes is medically important pathogenic fungi which causes ringworms to humans.



Slime Molds-1 Slime molds are organism which look very

similar to the mycelial fungi but differ from the true fungi in two ways.

The slime molds do not possess cell wall like true fungi.

The slime molds up- take their foods by the process of phagocytosis or endocytosis.

The members of slime molds are excellent tools used in the study of molecular biology and developmental biology.



Slime Molds-2 Two major groups of slime molds are:

Acellular slime molds Cellular slime molds

Acellular slime molds:- They are also called as plasmodial slime

molds. They can move like amoeba. They feed on bacteria and organic debris by

phagocytosing them. Plasmmodium is example of acellular slime

mold. Plasmodium produce haploid spores in

sporangium. The haploid spore germinate to produce

swimming myxamoebae in water.



Slime Molds-3 Cellular molds:-

The cellular molds are all haploid organism. Cellular molds live as haploid individual cell

called as myxamoeba. Myxamoebae feed themselves by

phagocytosing yeast, bacteria and dead organic matter.

The myxamoebae reproduce by mitosis and cytokinesis.

Dictyostelium is example of cellular mold.



Slime Molds-4 The picture of plasmodial slime mold is

shown below. This slime mold do not possess cell wall;

they can form the mass of protoplasm having numerous nuclei in it called as plasmodium.

Fig: Plasmodium of slime mold, Physarum



Slime Molds-5 In the sexual life cycle of plasmodial

slime mold, diploid adult cells form sporangia in which haploid spores are produced; during the favorable condition the spore germinate into amoeboid or flagellated cells.

Fig: sporangia containing haploid spores of slime mold Stemonitis



What We learn... Definition of Fungi General characteristics of fungi. Classification of fungi. General characteristics of slime molds.



Critical Thinking Questions Why the slime molds are not called as true

fungi?



Hints for Critical Thinking Questions

Definition of fungi not completely applicable to slime molds.



Study Tips Book

Title:Title: Microbiology Author:Author: Robert W Bauman Publication:Publication: Benjamin Cummings, San Francisco

Book Title:Title: Microbiology, An Introduction Author:Author: Tortora and et al. Publication:Publication: Pearson education, Singapore


End of the Presentation

Thank You!

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© 2008, YCMOU. All Rights Reserved.1 Online Counseling Resource YCMOU ELearning Drive… School of Architecture, Science and Technology Yashwantrao Chavan