Rhizopus

Class: Zygomycetes

Order: Mucorales

Family: Mucoraceae

Genus: Rhizopus

Rhizopus is commonly called bread molds. It is a saprophytic fungus found growing on bread, jam, pickles, decaying vegetables and fruits etc. the plant body consists of white cottony mycelium growing over the substratum. The young mycelium consists of long aseptate coenocytic hyphae. The older mycelium has three types of hyphae

1. Stolons : they are staut cylindrical creeping hyphae . They are differentiated in to nodes and inter nodes.

2. Rhizoidal hyphae: it produces at the node of the stolon .they are highly branched and penetrated into substratum .they provide courage and absorb food.

3. Sporangiopore: they are Arial staut hyphae which arise from substratum from the time of asexual reproduction. They develop from the node in clusters. Initially the hyphae have the cell wall made up of fugal cellulose. It encloses the cytoplasm. Hyphae are asepetate coenocytic, small vacuoles, oil droplets and glycogens are distributed in the cytoplasm.

ASEXUAL REPRODUCTION

It is by the formation of spore. The sporangiopore are short staut and arise at the node of stolon in clusters. A single sporangium is developed at the apex of each sporangiopore. Each sporangium is spherical in shape with the columella in the centre. The space between the columella and the sporangial wall is filled with uni- nuclei, non-motile aplanospore. The spores are liberated by breaking of the sporangial wall they germinate to form new mycelium.

SEXUAL REPRODUCTION

It is isogamous bind gematangial copulation. The sex organs develop when two mating strands + and - comes close to each other. The two gametangia on the opposite strands are formed as protruebalance. The nuclei moves to the tip and separated from the remaining pro-gametangia by a septum. The remaining part forms the suspensor. The wall of the gametangia meets, dissole and the nuclei fuses to form coenozygospore , which develops a thick wall and form a zygospore . On germination it produces a pro-mycelium and a terminal sporangium.

Posted in: Microbiology