Evaluation of antimicrobials on spores germination and outgrowth of bacteria isolated from alcohol fermentation process

Abstract

The increase of the contamination level of sugar-cane-juice after heat treatment has been one of the main problems faced by alcohol industry today. One of the most probable sources of it is the spore’s germination which are activated by the heating of the sugar-cane-juice. Basing in the assumptions, this work was undertaken to evaluate the activity of some antimicrobials on the bacterial spore’s germination and outgrowth. Spores suspensions having 107-lO> spores/ml of Bacillus subtilis, Bacillus coagulans. Bacillus megaterium. Bacillus brevis, Bacillus stearothermopbiius and Sporolactobaciltus sp. were tested. After activated by heating at 80°C for 10 minutes they were cultivated in sugarcane-juice and tested against Virgrniamycin 1,0; 2,0 and 3,0 ppm, Penicillin V Potassic 1.0; 2,0 and 3.0 ppm, Kamoran HJ 1;0; 2,0 and 3.0 ppm. Tetraciciin 55,0; 50,0 and 100,0 ppm and Quaternary Ammonium (Bactol Q, Adesol A-207) 20,0; 30,0 and 40,0 ppm. Higher spore germination and outgrowth percentage of inhibition occurred for all antimicrobials at the higher concentrations and 6 hours of incubation. The most effective antimicrobial for spore germination and outgrowth inhibition was Bactol Q, pointing out that it could be a useful! antimicrobial for controlling the increase of contamination after sugar-cane-juice heat treatment