• Corpus ID: 3132933

Hop acids as natural antibacterials can efficiently replace antibiotics in ethanol production

@inproceedings{Rckle2010HopAA,
  title={Hop acids as natural antibacterials can efficiently replace antibiotics in ethanol production},
  author={L. R{\"u}ckle and Thomas Senn},
  year={2010}
}

• L. Rückle, T. Senn
• Published 2010

This study was carried out at the Fermentation Tech nology Institute of the University of Hohenheim. The aim of the study was to evaluate the potential of hop acids as natural anti bacterials in distillery mashes for alcoholic fermentation. LactoStabTM and IsoStabTM were investigated for their effect on growth and lactic acid production by two selected strains of lac tobacilli. The potential of improving ethanol yields by use of LactoStabTM and IsoStabTM du ring alcoholic fermentation of wheat mash and sugar beet molasses mash was monitored. Penicillin G and Virginiamycin were used as referential substances for comparison of antiba cterial activity. LactoStabTM and IsoStabTM prevented growth of lactobacilli and production of lactic acid at ppm levels. Production of l actic acid and acetic acid was blocked at inhibitory concentrations of LactoStabTM and IsoStabTM. Both substances acted bactericidal wh en inhibitory concentrations were doubled. Of all tested antibacterials, Virgini amycin was most effective and acted bactericidal at a concentration of only 0.5 ppm. However, ethanol yields obtained at inhibitory/ bactericidal concentrations of hop acids were comparab le to those obtained with inhibitory/ bactericidal concentrations of antibiotics. Penicillin G, at a concentration of only 0.25 ppm, inhibited bacteria growth in most trials, but induced resistance in L. fermentum in wheat mash fermentation. IsoStabTM and LactoStab TM are available to the ethanol industry through BetaTec Hop Products GmbH. They consist of components contained in beer and spent hop s and bear no risk for human or animal health . Thus, they provide an exce llent, safe alternative to control bacteria in ethanol fermentations.