Evaluation of lactic acid bacteria isolates for silage fermentation inoculant in Thailand by using a modified pouch method

A modified pouch method was used to evaluate 13 strains of lactic acid bacteria (LAB) for silage fermentation inoculants to make good-quality silage in Thailand. Among them, strain SP 1-3, isolated from corn silage and tentatively assigned to Lac tobacillus plantarum, exhibited an inherent tolerance for high incubation temperature and lactic acid. Strains CS 5-5 and KS 1-9, tentatively assigned to Pediococcus sp., also exhibited similar properties to strain SP 1-3, but their levels of lactate tolerance were weaker than that of strain SP 1-3. Strain CS 1-8, isolated from TMR silage and assigned to Pediococcus sp., grew well at the early stage of silage fermentation (within 24-h), but did not accumulate a large amount of lactate during the long-term fermentation (21 days). Based on these results, laboratory-scale silage of napiergrass inoculated with strain SP 1-3 or CS 1-8 was prepared. The fermention quality of silage inoculated with both strains obviously improved the amount of lactate produced and reduced the counts of coliform bacteria and yeast. From these results, both strains, SP 1-3 and CS 1-8, were evaluated as favorable silage fermentation inoculants in tropical regions such as Thailand.