ABSTRACT
A bioreactor is a vessel in which a biological reaction or change takes place. The biological system may include enzymes, micro-organisms, animal cells, plant cells, and tissues. The bioreactor is a place where an optimum environment is provided to meet the needs of the biological system so that a high productivity of the bioprocess is achieved. Bioreactors are also considered as crude models of natural ecosystems since they are used to study, under controlled laboratory conditions, the different types of interactions that arise between micro-organisms inhabiting the same environment [375]. Bioreactors of various types are used extensively for the manufacture of useful bioproducts and in the biological treatment of wastes. Bioproducts are used directly as drugs or food or are used indirectly as materials in pharmaceutical, food, and chemical industries. Biological treatment processes, on the other hand, when properly designed and operated, have the potential to be a relatively cost-effective method for hazardous substance removal.
