关键词: 发酵产物, 有氧稳定性, 乳酸菌, 青贮

Abstract:

To understand the effects of lactic acid bacteria (LAB) inoculation on the fermentation products, aerobic stability and microbial communities of silage, wilted Italian ryegrass and whole crop corn were stored in laboratory silos with and without inoculations of Lactobacillus rhamnosus and Lactobacillus buchneri. The silos were opened after 14, 56 and 120 days and then subjected to aerobic deterioration for 7 days. Intensive alcoholic fermentation was found in untreated Italian ryegrass silage; the sum of ethanol and 2,3-butanediol contents at day 14 was about 7 times higher than that of lactic and volatile fatty acids. Alcoholic fermentation was suppressed by L. rhamnosus and L. buchneri inoculation, and lactic acid and acetic acid became the dominant fermentation products. Italian ryegrass silages were deteriorated in untreated and L. rhamnosus-inoculated silages, whereas spoilage was not found in L. buchneri-inoculated Italian ryegrass silage. In whole crop corn silage, L. rhamnosus did not affect the fermentation, while L. buchneri decreased the lactic acid content and increased the acetic acid content. Aerobic stability was enhanced in whole crop corn silage stored for a long period (120 days), with the increase of acetic acid content even without L. buchneri inoculation. A higher aerobic stability was achieved with a shorter ensiling period (56 days) in L. buchneri-inoculated whole crop corn silage.

Key words: Fermentation product, Aerobic deterioration, Lactic acid bacteria, Silage