Fermentation types are classified into different classes based on various aspects like based on feeding substrate to fermenter, based on need of supply of aeration, based on need of light etc. Based on feeding substrate to fermenter, Batch fermentation, Continuous fermentation and Fed-batch fermentation are the key modes. In batch fermentation, every material for process of fermentation including substrate, inoculum and all the process parameters are set and filled in a fermenter and the process is set on and until the total process comes to an end neither substrate is added into fermenter nor product is taken out of fermenter. In fed-batch mode we find both modes of operations of batch and continuous modes, where substrate is added at fixed time intervals during the fermentation process.