Succession of lactic acid bacteria in wilted rhodesgrass silage assessed by plate culture and denaturing gradient gel electrophoresis

Lactic acid bacteria (LAB) in low-moisture rhodesgrass (Chrolis gayana Kunth) silage, involved in the fermentation process, were determined by plate culture and denaturing gradient gel electrophoresis (DGGE). The first harvest of rhodesgrass was wilted (581 g dry matter kg-1) and stored in laboratory silos for 15, 30, 90 and 180 days. The concentration of acetic acid was found to be more than that of lactic acid until day 30, while lactic acid was the major fermentation product after day 90. Both plate culture and DGGE analyses indicated that Lactobacillus plantarum, Lactobacillus brevis and Lactococcus lactis were the principal LAB present during the period of ensiling. Similar results were obtained with the two methods with respect to the LAB species, but neither of the methods could account for the change in the fermentation products over the period of ensiling.