Bioethanol production from C1 gases using alternative media by syngas fermentation

The main aim of the present study was to evaluate the effects of the presence or absence of trace elements and yeast extract on growth and ethanol production by Clostridium ragsdalei grown on C1 gas dominated syngas (60% CO, 10% CO2, 10% CH4, 10% H-2, 10% N-2). Comparison of whey powder and glucose syrup as low-cost substitutes helped develop a more cost-effective medium formulation to produce ethanol from syngas with significantly higher yields, achieving up to a 3.8-fold improvement with co-utilisation of syngas and glucose syrup. In addition, the results provided further insights into medium manipulation and possible modifications to decrease total costs for increased ethanol production by solventogenic acetogens via syngas fermentation by achieving a 15.6% reduction in the cost of fermentation medium.