CHAPTER   ONE
INTRODUCTION
Rhizopus nigricans belongs to a group of fungi known as the “black moulds”.  It is also known commonly as the “read mould” because if grows freely on moist, state bread.  It appears as a delicate black mass.  It is a common mould, which is widespread in occurrence.  Rhizopus forms a mass of soft, closely woven white silky threads.  This mass, which is known as a mycelium is the vegetative part of the Fungs.  Each silky thread like structure is a hypha.  The ‘mycelium grows not only on the surface of the bread but into it as well.   The bread is known as the substrate.
The mycelium consists of three sorts of hyphae.  These three sorts of hyphae as stolons which grow horizontally on the substrate (bread), rhizoid or root like hyphae which arise at points where the stolons come into contact with the substrate and sport-angiophores.  The rhizoids are much branched hyphae which penetrate into the substrate.  They are able to digest and absorb organic food.  The sporangiophores are erect unbranched hyphae arising from the stolons at the same points where rhizoids are formal.
They grow vertically upwards and give rise to the reproductive structures called sporangia.  (Sargini et al, 1979).
The common bread mould (Rhizopus) finds new bakery items by means of air-born spores.  Once the baked good is invaded, it won’t be long before black sporangia full of spores are formed.  Rhizopus stolonifera (black mould) causes the black bread mould that forms cottony masses on the surface of moist