Alcoholic fermentation in the presence of microwaves

Bioethanol is the world's leader biofuel and it is produced by fermentation from glucose feedstocks. The fermentation rate is quite low and any method of increasing the reaction rate is welcome. The main goal of our research is to identify the domain for microwave Specific Absorption Ratio (SAR) which leads to an increase in fermentation rate of Saccharomyces cerevisiae without affecting its viability. For this purpose, an installation was setup which allows for glucose fermentation to be carried out in the presence of microwave, with good control on SAR and on temperature of the fermentative medium. An optimum SAR domain, between 15 and 25 W kg(-1), was determined, in which a significant boost of glucose fermentation manifests, with an increase in fermentation rates of up to 20%. Based on the observations made through electron and optical microscopy on cell growth and viability, we have noticed that microwave irradiation favours ethanol production of the cells, against their growth.