EFFECT OF MICROORGANISMS ON THE FERMENTATION OF FUSARIUM SPP. CONTAMINATED BARLEY AND ITS DETOXIFICATION

Abstract

The work is dedicated to increase the efficiency of the processing of Fusarium contaminated barley biomass by using pretreatment of grains with antimicrobial lactic acid bacteria in combination with special selected strains of yeast for alcoholic fermentation. Bacteriocins producing lactic acid bacteria (LAB) have been isolated from Lithuanian spontanious rye sourdoughs. These LAB’s were attributing to Lactobacillus and Pediococcus genotypes and Lactobacillus sakei KTU05-06, Pediococcus acidilactici KTU05-07 and P. pentosaceus KTU05-08 species, PCR detection of LAB structural genes has been carried out. The contamination of barley with Fusarium spp. decrease the amount of ethanol during fermentation processes (R² = 0.868) and, contrary, increase the concentrations of higher alkohols (R² = 0.867). The efficiency of fermentation process could be increased by selecting yeast strains: a higher ethanol yield and a lower amount of higher alkohols was observed by using K. marxianus var. Bulgaricus. Other yeast strains – K. Marxianus show the same effect on fermentation processes as S. cerevisae. The treatment of contaminated barley with selected LAB has not a significant influence on bioethanol yield. But by using some LAB strains such as P. acidilactici and P. pentosaceus a higher amount of higher alkohols has been developed. Furthermore in all cases this biotechnological solution has positive influence on dried grains with solubles (DDGS) detoxification by decreasing the amount of DON in important raw material for feed production. The best detoxification effect has been achieved by using P. acidilactici or L. sakei for contaminated barley treatment and S. cerevisiae – for fermentation processes. So, by selecting LAB with antimicrobial activity in combiantion with yeast, the efficiency of the processing of Fusarium cantaminated barley can be significantly increased: biomass could be used for bioethanol production and DDGS – for feed.

DOI: http://dx.doi.org/10.5755/j01.ct.60.2.1617