Microwave as a pre-treatment of triticale for bioethanol fermentation and utilization of the stillage for lactic acid fermentation

Abstract

The aims of this research were to investigate the potential for improvement of bioethanol fermentation by microwave pre-treatment of triticale, as well as the possibility of using triticale stillage (a by-product of bioethanol fermentation) as a suitable medium for lactic acid fermentation, either without or with the optimal addition of CaCO3. The results showed that an adequate microwave pre-treatment (270 and 450W) marginally improved bioethanol production, giving a slightly higher yield of the bioethanol produced (by 3.95%). Lactobacillus fermentum PL-1 was used for subsequent lactic acid fermentation of the stillage that remained after bioethanol fermentation. Results showed higher pH decrease and higher acidity in the samples without the addition of CaCO3. Consequently, higher concentrations of l- and d-lactic acid were determined in the samples with the addition of CaCO3, as well as better viability of cells and the complete glucose utilization. © 2014 Elsevier B.V.