Abstract:
Biobutanol and bioethanol are liquid biofuels that can be produced from biomass by group of anaerobic bacteria. The objective of this study is to screen anaerobic bacteria especially Clostridium spp. from agricultural waste and dung in Thailand for biofuel production. The modified synthetic MS media are 30 g L⁻¹ of sucrose mixed with 30 g L⁻¹ of glucose were used to isolation. Para-aminobenzoic acid and biotin were added as additional vitamin. Modified MS media was supplemented with 1% butanol. Fermentation products were determined first. Morphology and biochemical reaction in each isolate were analyzed. Sixteen and twenty two isolates of anaerobic bacteria were screened from sweet sorghum bagasse and cow dung that were collected from Saraburi and Pathumthani provinces in Thailand, respectively. But twenty five of them showed Clostridium spp. characteristics are gram positive, rod-shape, sub-terminal spore-forming, motile, sulfite-reducing and produce solvent. They cant reduce nitrate, not produce lecithinase activity and non-haemolysis were identified as primary criteria to non pathogen. From all isolates, isolate CG1 from cow dung was produce the highest concentrations of butanol ethanol and acetone reaches 3.61, 2.11 and 0.02 g L⁻¹ respectively and tolerant to butanol concentration of 12 g L⁻¹. In bioreactor 5 L, isolate CG1 has produced the highest concentrations of butanol ethanol and acetone reaches to 9.9 g L⁻¹ and 4.28 and 0.27 g L⁻¹ at 144 hrs respectively.