Fungi: Introduction.

 

Introduction:

• Fungi is a group of eukaryotic organisms which exist as Saprophytic, parasitic as well as in symbiotic form.

• Study of fungi is called “Mycology”.

• They have rigid cell walls made up of “Chitin”.

• The fungal cells contain well differentiated nuclei surrounded with a nuclear membrane.

• They have simple oval cells or tubular cells showing branching.

• The vegetative body of the fungi may be unicellular or composed of microscopic threads called hyphae.

• Hyphae can grow and form a network called a mycelium.

• Yeasts are unicellular fungi that do not produce hyphae.

• All fungi are chemoautotrophs and require organic compounds for energy and carbon source.

• They are aerobic or facultative anaerobic in nature.

• They divide by asexual, sexual or both types of reproduction, they are known to form spores.

• There are sexual and asexual spores. Sexual spores e.g. Oospores, Zygospores, Ascospores, Basidiospores, etc. and Asexual spores are Sporangiospores, Aplanospores, Zoospores, Conidia, etc.

Difference Between Bacteria and Fungi

Sr No.	Characteristic	Fungi	Bacteria
1	Cell Type	Eukaryotic	Prokaryotic
2	Optimum pH	4 to 6	6.5 to 7.5
3	Cell membrane	Sterols present	Sterols absent (Exception: Mycoplasma)
4	Optimum Temperature	25 to 30°C (Saprophytes) 32 to 37°C (Parasites)	32 to 37°C  (mesophilic)
5	Oxygen Requirement	Strict Aerobe (Some Moulds) Facultative Anaerobe (Some Yeasts)	Aerobic to Anaerobic
6	Photosynthesis	None.	Some.
7	Source of Carbon	Organic	Organic and Inorganic
8	Concentration of Sugar required in the lab. media	4 t0 5%	0.5 to 1%
9	Cell wall component	CHitin, Cellulose or Hemicellulose.	Peptidoglycan
10	Antibiotic susceptibility	Sensitive towards Antifungal antibiotics like Griseofulvin. Resistant toward Penicillin and most of other broad spectrum antibiotics like Chloramphenicol	Sensitive to Penicillin and other broad spectrum antibiotics. Resistant to Griseofulvin.