Among all three pretreatment methods described here MCons is thebest because mixed microbial source are used in this process whichreduces chances of contamination and also the cost of maintenance. Enzhave high operation costs due to additional care should be taken at thetime of pretreatment. In fungal pretreatment much care is requirepreventing the contamination of one species of fungi from the otherbecause contamination may result in lower amount of biofuel production.