The fermentation processes towards production of both the acids and solvents involves two phases, acidogenic and solventogenic phases. Acids like acetic acid, butyric acid are the major products obtained during the first acidogenic phase, which are then re-assimilated and converted to solvents like Biobutanol, Ethanol and Acetone. Initially, Clostridium species was isolated and inoculated into a production media containing microbial growth requirements, including Liquid Pineapple waste used as carbon source . Samples withdrawn at 4 hour intervals were subjected to analysis using Gas Chromatography (GC). Kinetic evaluations of the data obtained were performed accordingly. The bacteria displayed a long-lag phase during the fermentation period with aspecific growth rate of 0.02 h-1, maximum specific growth rate of 0.04 h-1, and a generation time (td) of 33 h. The cell productivity was achieved as 0.02 g/L/h with a biomass yield of 4.81 g/g. The study further recorded significant yield of acids (Acetic acid 15.3 g/g and butyric acid 13.7 g/g) as compared to that of the solvents (Ethanol 5.58 g/g, Acetone 1.56 and biobutanol 1.29 g/g), based on substrate utilization. The yields in terms of cell biomass formation also revealed higher values of acids (Acetic acid 3.27 g/g and butyric acid 2.67 g/g) compared to solvents (Ethanol 1.09 g/g, Acetone 0.37 and Biobutanol 0.31 g/g). Subsequently, the productivity of acids (Acetic acid 0.23 g/L/h and butyric acid 0.09g/L/h) was recorded higher as equated to the solvents (Ethanol 0.04 g/L/h, Acetone and Biobutanol 0.01 g/L/h). This study ultimately demonstrated that liquid pineapple waste can be greatly utilized as a carbon source for microbial growth during biological process, and the bacteria used can be an apposite producer of Acetic and Butyric acids.
Key words: Clostridium, Kinetic Assessment, Solvents
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