Production of biobutanol by clostridium beijerinki sr1 using sea water medium

Abstract

Biobutanol produced by Clostridium sp. via acetone-butanol-ethanol fermentation (ABE) under strict anaerobic condition served as the most promising biofuel. During ABE fermentation, culture undergoes a metabolic shift from acidogenic phase to solventogenic phase for the formation of solvents. In this preliminary study, production of biobutanol using locally isolated strain using sea water was performed in batch culture. Analysis of filtered sea water from Bakar Batu, Johor showed total carbon and nitrogen of 0.1629% (w/v) and 0.003% (w/v), respectively with C/N ratio of 0.0016. The sodium, calcium, magnesium and potassium concentration were 176.60, 21.92, 23.63 and 58.96 ppm, respectively. The strain used was isolated from contaminated lake sediment in Port Klang, Selangor was further identified as Clostridium beijerinckii SR1 using 16S rRNA studies with accession number of KJ934638. Application of complete Reinforced Clostridium Medium (RCM) with sea water resulted in highest butanol production and productivity of 0.416 g/L and 0.009 g/L/h, respectively with yield of 15.46%. The Yp/s and Yp/x value obtained were 0.15 g/g and 2.10 g/g, respectively. Total cell concentration (X) obtained was 0.23 g/L with µmax and doubling time (td) of 0.090 h-1 and 15.47 h-1, respectively. Application RCM medium without an addition of vitamin solutions (thiamine and biotin) resulted in biobutanol production and productivity of 0.398 g/L and 0.008 g/L/h with yield of 15.48%. Total cell concentration was 0.27 g/L with µmax and doubling time (td) of 0.100 h-1and 14.06 h-1, respectively. Thus, sea water which contains essential minerals in acceptable concentration was successfully utilized for potential biobutanol production in future.