CO is one of the toxic components of syngas, which is the major source of air pollution. Syngas
fermentation technology has the ability to convert toxic gases into valuable biofuels, such as ethanol.
Fermentative ethanol production is an important method that can be used to promote environmental
protection. CO can be converted into ethanol, via the WoodeLjungdahl pathway, using Clostridium
ljungdahlii. The components of the growing mediumeeespecially the trace-element solution and yeast
extracteeare the main reasons for the high costs associated with this process, however, and this
especially impacts scaled-up operations. In this study, cheaper substitutes for these components were
used in order to determine their effect on ethanol production. The study comprised three main parts
eethe optimization of CO concentration, and the substitution of corn syrup and whey powder in the
process. The optimum volume of CO for ethanol production was found to be 10 mL. Corn syrup can be
used instead of trace-element solution, but the use of yeast extract with the corn syrup was determined
to be essential. Up to 1.4 g/L ethanol production was observed with the addition of 15 mL corn syrup.
Whey powder had the advantage of being usable without yeast extract, with up to 2.5 g/L ethanol being
produced from a 30-g/L concentration. The main finding was that either corn syrup or whey powder can
be used as substitutes for expensive basal-medium components.