Characteristics of lactic acid bacteria isolated from forage crops and their effects on silage fermentation

Enterococcus faecalis CA 6, E faecium CA 10, E casseliflavus CA 13, Weissel la paramesenteroides CA 14, Leuconostoc pseudomesenteroides CA 17, Pediococ cus pentosaceus CA 21, P acidilactici CA 25 and Lactobacilus plantarum CA 2 8 isolated from forage crops were characterised and their effects on silage fermentation were studied. Strains CA 6, CA 10 and CA 13 grew only at rela tively high pH (above 5.0), while strains CA 21, CA 25 and CA 28 were able to grow at pH values below 4.0. Strain CA 25 grew at 50 degrees C, but the others did not grow at above 45 degrees C. These strains were used as inocu lants for perennial ryegrass silage ensiled at 25 or 45 degrees C. At 25 de grees C all strains significantly (P<0.01) reduced the pH value and butyric acid content and greatly increased the lactic acid content compared with t he control, particularly strains CA 21, CA 25 and CA 28. At 45 degrees C st rain CA 25 markedly improved the fermentation quality of silage, but the ot hers did not. These silages had a lower lactic acid content and a higher pr oportion of L(+)- to total lactic acid than equivalent silages kept at 25 d egrees C. The results confirmed that at 25 degrees C P pentosaceus CA 21, P acidilactici CA 25 and L plantarum CA 28 were the most effective, whereas at 45 degrees C only P acidilactici CA 25 had a beneficial effect on silage fermentation quality. (C) 2000 Society of Chemical Industry.