Isolation and Identification of Dominant Lactic Acid Bacteria from Brassica napus and Their Effects on Fermentation Quality and Aerobic Stability of Silage
The aim of this study was to screen the naturally dominant lactic acid bacteria in Brassica napus si-lage,and determine their effects on fermentation quality and aerobic stability of forage rape silage,so as to provide guidance for efficient feed utilization of Brassica napus resources.Firstly,the isolated lactic acid bacte-ria were identified by molecular biology method(16S rDNA sequencing),and the identified lactic acid bacte-ria strains were analyzed for acid production and growth characteristics.Further,the selected dominant lactic acid bacteria were inoculated into Brassica napus for silage,and the wrapped silage method was adopted.Four treatments were set up in the experiment:the control(CK)treatment was inoculated no bacterial strains;the Lactobacillus buchneri(LB)treatment was inoculated the Lactobacillus buchneri,and the inoculation amount was 2×108 CFU/g;the Enterococcus faecium(EF)treatment was inoculated the Enterococcus faecium,and the inoculation amount was 2×108 CFU/g;the Lactobacillus buchneri+Enterococcus faecium(LBEF)treat-ment was inoculated the Lactobacillus buchneri+Enterococcus faecium,and the inoculation amount was all 1× 108 CFU/g.The results showed as follows:1)26 lactic acid bacteria were isolated in this experiment,of which 25 strains were identified as Lactobacillus buchneri and 1 strain was Enterococcus faecium.Two of them showed the strongest acid production and growth characteristics.2)On 60 days of fermentation,the contents of neutral detergent fiber and propionic acid in LBEF treatment were significantly lower than those in CK and EF treatments(P＜0.05);the content of acid detergent fiber in EF and LBEF treatments was significantly lower than that in CK treatment(P＜0.05),and the content of lactic acid was significantly higher than that of CK and LB treatments(P＜0.05);the pH,ammonia nitrogen content and mold number in LB,EF and LBEF treat-ments were significantly lower than those in CK treatment(P＜0.05).3)On 5 days of unpacking,the lactic acid content and lactic acid bacteria number in EF and LBEF treatments were significantly higher than those in CK and LB treatments(P＜0.05),the content of propionic acid in LBEF treatment was significantly lower than that in other treatments(P＜0.05),the content of ammonia nitrogen in LB and LBEF treatments was sig-nificantly lower than that in other treatments(P＜0.05),the numbers of yeast and mold in LBEF and LB treat-ments were significantly lower than those in CK and EF treatments(P＜0.05).In conclusion,the co-inocula-tion of Lactobacillus buchneri and Enterococcus faecium in Brassica napus silage can use nutrients with less substrate to produce lactic acid,reduce the pH of fermentation system,inhibit protein spoilage and mold growth,and improve the aerobic stability of Brassica napus.[Chinese Journal of Animal Nutrition,2024,36(8):5411-5421]
万方数据
维普
