Premium
Characteristics of lactic acid bacteria isolates and their inoculating effects on the silage fermentation at high temperature
Author(s) -
Chen M.M.,
Liu Q.H.,
Xin G.R.,
Zhang J.G.
Publication year - 2013
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/lam.12018
Subject(s) - silage , microbial inoculant , pediococcus acidilactici , lactobacillus rhamnosus , wilting , fermentation , lactic acid , biology , food science , lactobacillus plantarum , lactobacillaceae , bacteria , lactobacillus , agronomy , genetics
Thermotolerant strains of lactic acid bacteria (LAB) were screened for their suitability for silage making at high temperatures. Four selected strains were identified by 16S rRNA sequencing analyses and added to unwilted and wilted Italian ryegrass for ensiling at 45°C. All four strains (HT1, HT2, HT3 and HT4) grew at 50°C and pH 4·0. Strains HT1 and HT2 were identified as L actobacillus rhamnosus ; HT3 and HT4 were identified as L act. fermentum . Strains HT1 and HT2 were the most effective at improving the fermentation quality of Italian ryegrass silage, irrespective of wilting, as indicated by lower pH values, less NH 3 –N, and more lactic acid. In contrast, strains HT3, HT4 and a commercial inoculant consisting of L act. plantarum and P ediococcus acidilactici conferred no or reduced benefits. Wilting alone did not improve the fermentation quality of I talian ryegrass at 45°C. Inoculating with thermotolerant L act. rhamnosus HT1 and HT2 could improve the fermentation quality of silage at high temperatures. Lactobacillus rhamnosus HT1 and HT2 can be used as inoculants for silage making in the tropics and subtropics and could play an important role in developing silage production in such regions. Significance and Impact of the Study Grasses are often difficult to ensile in the tropics and subtropicsbecause of the high temperatures there. To solve this problem, we screened for thermotolerant lactic acid bacteria and obtained two valuable strains of Lactobacillus rhamnosus , HT1 and HT2, which proved to be beneficial to silage fermentation at high temperatures. Lactobacillus rhamnosus HT1 and HT2 can be used as inoculants for silage making in the tropics and subtropics, and will play an important role in developing silage production in such regions.