不同乳酸菌添加剂对青贮黑麦草和青贮玉米微生物群集的影响

Microbial Communities of Whole Crop Corn and Wilted Italian Ryegrass Silage Inoculated with and without Different Lactic Acid Bacteria Inoculants

在青贮黑麦草(Lolium perenne)和青贮玉米(Zeamays)中添加鼠李糖乳杆菌和布氏乳杆菌,研究其对微生物群集的影响,青贮饲料贮藏时间为14,56,120 d。结果表明:添加布氏乳杆菌的青贮黑麦草组细菌与真菌群集都很稳定,大肠菌中的Erwinia persicina,Pantoea agglomerans和Rahnella aquatilis在青贮黑麦草对照组中被发现,鼠李糖乳杆菌组没有发现。Saccharomyces cerevisiae和Pichia anomala是对照组与鼠李糖乳杆菌组青贮黑麦草中的主要真菌;P.anomala在布氏乳杆菌组未检测到。Candida magnolia,Cryptococcusflavus和Candida inter media在青贮玉米原料与发酵过程中均检测到,Candida glabrata和Candida quercitrusa只在发酵过程检测到。有氧腐败发生时,青贮玉米真菌菌群发生明显变化,Sacharomyces exiguus,Saccharomyces martiniae,Pichia fermentans,Pichia deserticola和Pichia kudriavzevii可在腐败的青贮玉米中检测到。这表明添加乳酸菌制剂可以改变青贮黑麦草的菌群,但是对青贮玉米菌群影响较小,发生腐败时真菌菌群与细菌菌群均发生变化。

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 Lactobacillus rhamnosus and Lactobacillus buchneri inoculants. The silos were opened after 14, 56 and 120 days and then subjected to aerobic deterioration for 7 days. Enterobacteria such as Erwinia persici- ha, Pantoea agglomerans and Rahnella aquatilis were detected in untreated grass silage, whereas some of these bacteria disappeared or became faint with L. rhamnosus grass treatment. Both Saccharomyces cerevisiae and Pichia anomala were the main fungi in untreated and L. rhamnosus-inoculated grass silages however, P. anomala was not visibly seen in L. buchneri inoculated grass silage either at silo opening or after exposure to air. Candida mag- nolia, Cryptococcus flavus and Candida interrnedia were detected in the pre-ensiled corn crop and the silage, whereas Candida glabrata and Candida quercitrusa were identified exclusively in the corn silage. The marked change of fungal community was seen after aerobic spoilage; Saccharomyces exiguus, Saccharomyces martiniae, Pichia fermentans, Pichia deserticola and Pichia kudriavzevii appeared in the spoiled corn silage. These results indicated that LAB inoculation induced the few change of bacterial and fungal communities in corn silage, and the substantial changes of fungal community and bacterial community occurred when the silage was spoiled.