*4.3.2 Solid state fermentation*

When fermentation is performed on nonsoluble materials in the absence of free flowing nutrient media, so that the material used can serve as a platform for support as well as nutrients; it is termed as solid state fermentation. While compared for their potential it was found SSF offers various opportunities over SmF because they are eco-friendly on account of lower energy requirements, produce lesser wastewater and they are based on employment of waste solid biomass [90]. Further advantages of SSF over SmF include prevalence of nonaseptic conditions, a wide variety of substrate are available, low capital cost, inexpensive downstream processing [91], higher product concentration, high reproducibility, lesser space requirements (compact fermenters), easy contamination management [92]. It is observed that production cost was decreased about 10 fold in SSF over SmF.
