Microbial Biotechnology Lecture:7 Microbial Biotechnology

3- Fungi

Fungi (singular: fungus) are Eukaryotes They may be unicellular (yeast)- are oval in shape larger than bacteria OR multicellular (mold)- form visible masses called mycelia compose of long filaments ( hyphae) cottony growths on bread&fruit). Large multicellular like mushroom look somewhat like plant but they are not photosynthesis Cell wall compose of chitin Fungi reproduce sexually or asexually They absorbing solution of organic materials to get their nourishements

These are saprophytic or parasitic organisms possessing relatively rigid cell walls. The largest and most versatile of all microbes Fungi can be very helpful and humans have used them in The food industry - brewing beer, making bread rise Medicine – making antibiotics

Fungal Structure Sporangia: Spore producing body. Sporangiophore: Rhizoids Sporangia: Spore producing body.  Sporangiophore: Filamentous stalk on which the sporangium forms. Rhizoids: The sub-surface hyphae are specialized for food absorption.

Yeasts are classified in the Fungus kingdom Over 1.5 million species estimated to exist Only 10% identified & classified Fungi are important sources of antibiotics and blood cholesterol-lowering drugs.

Saccharomyces (yeast) Ferments carbohydrates in flour or malt and gain energy from this digestion. Carbon dioxide gas (in bread) and ethanol (in beer) are by-products of Fungi. Have chitin in cell wall Yeast cells are generally larger in size and have larger genomes than most bacteria Mechanisms of gene expression in yeast resemble those in human cells (valuable model organism) Several human disease genes have been discovered in yeast. Many can grow in aerobic or anaerobic conditions Many different types of yeast mutants are available

Saccharomyces cerevisiae Commonly studied strain of yeast Microorganism behind the most common form of fermentation 1st eukaryotic organism to have its complete genome sequenced 16 linear chromosomes 12 million base pairs ~ 6,300 genes

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4- Protozoa

Protozoa Protozoa are unicellular Eukaryotic microbes Move by flagella, cilia, pseudopods Have variety of shapes, Lives free or as parasite They absorb or ingest organic compounds from their environment They reproduce by sexually or asexually Diameters in the range of 2-100 μm.

C- Ciliophora: motile by cilia. Example: Balantidium coli. The most important groups of medical protozoa are: A-Amoeba: Entamoeba species. Mode of Motility: pseudopodia. B- Mastigophora: Mode of Motility: the Flagella. Gastrointestinal flagellates: Giardia intestinalis Urogenital flagellates: Trichomonas vaginalis Tissue and blood flagellates: Trypanosoma, Leishmania . C- Ciliophora: motile by cilia. Example: Balantidium coli. D- Sporozoa: intracellular infection. Example: Plasmodium that cause Malaria.

Amoeba Fluid state of cytoplasm enables it to change its shape easily Pseudopodia wrap around a prey in order to trap it in a food vacuole for intracellular digestion

Plasmodium Parasitic heterotroph Mosquitoes carry and infect humans causing malaria

Algae are also Microbes Algae photosynthesise – taking their energy from the sun, and producing oxygen in the process. Algae are thought to produce over 50% of the oxygen in the world.

Algae Are photosynthesis Eukaryotes with wide variety of shapes Reproduce sexually or asexually Cell wall like plants are compose of cellulose Algae are abundant in fresh water and salt Play an important role in the balance of nature (produce Oxygen& carbohydrates). Major food source of small aquatic animals

Chlorella Single-celled green algae Non-motile Cell wall of cellulose