NOVELTY - Producing bio-fuel involves providing feed stock (1) into pre-fermentation system; directing amended feed stock from pre-fermentation system to fermentation system that comprises two bio-reactors comprising at least one bio-carrier medium disposed within bio-reactor, where at least one microorganism preselected for fermentation capability, is immobilized on medium surface by chitin, and microorganism propagates on the surface; and oxygen source to provide oxygen to first bio-reactor; generating effluent from fermentation system; and distilling effluent from fermentation system.    USE - For producing bio-fuel (claimed), e.g. ethanol.    ADVANTAGE - The process provides continuous flow system for production of bio-fuels using microbial cultures. The present method does not utilizes batch type production, but follows a continuous flow protocol that eliminates much downtime inherent in conventional bio-fuel production systems while greatly reducing space and equipment requirements. Production is enhanced via controlled program of aeration for microbial growth and anaerobic conditions to ensure fermentation efficiency. As the system becomes more tolerant of alcohol content, efficiency increases. Feedstock include, but are not limited to, material normally discarded from food production facilities including drink syrups, juices or waste water from corn or sugar processing plants. By promoting in-situ growth of desired yeast and/or other microbial populations, the method promotes microbial growth and acclimation within the fermentation tanks, piping and associated elements of the present method. Over time, the microbial growth results in spread of yeast and/or other beneficial microbial agents, and improves fermentation process and overall system efficiency.    DETAILED DESCRIPTION - Producing bio-fuel involves: providing feed stock (1) into pre-fermentation system comprising mixing tank, nutrient source and an antibiotic source; directing amended feed stock from the pre-fermentation system to fermentation system that comprises first and second bio-reactors comprising at least one bio-carrier medium disposed within the bio-reactor, where at least one microorganism, preselected for fermentation capability, is immobilized on the surface of the medium using chitin, and the microorganism propagates on the surface of the medium; and an oxygen source for providing oxygen to the first bio-reactor; generating effluent from fermentation system; and distilling effluent from fermentation system.    DESCRIPTION OF DRAWING(S) - The figure shows schematic layout of pre-fermentation stage of the continuous flow ethanol production system.    Raw feed stock (1)    Centrifuge (2)    Solid collection vessel (3)    Line (4, 9, 12, 14, 18)    pre-fermentation nutrient amendment/antibiotic tank (5)    Mixer (6, 17)    Water supply line (7)    Nutrient supply tank (8)    Metering pump (10, 13)    Antibiotic supply tank (11)    Transfer pump (15, 19)    Pre-fermentation holing tank (16)