Mucor.

Life history of Mucor

CLASSIFICATION

Division. – mycota

Sub-Division. – Eumycotina

Class. – zygomycates

Order. – mucorales

Family. – mucoraceae

INTRODUCTION

Mucor, the most common member of the Mucoracene, has more than 100 species. It is saprophytic fungus.

OCCURRENCE

Mucor is found throughout the world. Out of 100 species 17 species of Mucor are found in India. Some Indian species are Mucor hiemalis, Mucor indicus, Mucor mucedo, Mucar praine.Most of the species of Mucorare saprophytic on a variety of materials including foodstuffs rich in sugar and starch. In damp conditions they spoil organic materials such as bread, jams, jellies, over ripe fruits, syrups, etc. Mucor emits a musty smell and honce it is called Muss (foul-smell). It is also found on leather. Some species of Mucor are coprophilous (dung-inhabiting) and few are strictly terrestrial Mucor mucedo and Mucor racemosus are common air contaminants.

Mucor also grows well on moist bread. Thus, it is commonly known as bread mould. It can be grown in laboratory by placing bread slices in a moist chamber at room temperature. The fungus appears in the form of white cottony or woolly growth within 2-3 days. This is also called pin muuld or blackmould because of its black spores.

Species of Mucor are known to cause mucoromycosis in domestic animals d

and human beings. It infect organ like lungs, brain etc, which may cause even death of the organism.Many species of Mucor are responsible for causing rotting of fruits and vegetables. Some species of Mucor, g, Mucor javanicus are used industrially for alcoholic fermentation.

VEGETATIVE STRUCTURE

Mucor is haploid plant. The thallus of Mucor consists of highly branched course coenocytic mycelium which forms white, grey or brownish cottony growth on the substratum. It appears as a loose fluffy mass of cotton. Mycelium differentiated into aerial and prostrate hyphae. The branches of mycelium are usually tapering to fine points. The prostrate hyphae serve as function of absorption and sometime serve as fixative. Young hyphae are without septa but they appear in older hyphae, when reproductive structures are developed.

In annerobic liquid cultures, especially in the presence of carbon dioxide, the hyphae break to form yeast-like bodies. This state of fungus is referred to as torula condition. If oxygen is made available it reverts to filamentous stage.

Hyphae consist of cell wall, plasma-membrane and protoplasm. The wall of hyphae is made up of chitin mycofibrils and chitosan. Besides these, polysaccharides, proteins, lipids, purines, pyrimidines and a few minerals (calcium, Magnesium etc.,) are also present in the cell wall.The cell wall is lines internally by a thin plasma-membrane which encloses the protoplasm. The cytoplasm is granular and contains numerous vacuoles of small size. Numerous nuciai are present and are distributed all over the cytoplasm. The food reserve is in the form of glycogen and oil droplets.