| The research was conducted to reveal the effects of epiphytic microbiota from legume and grass on fermentation quality and microbial community dynamics during the ensiling of alfalfa,red clover,Italian ryegrass and oat.The y-ray irradiation was used to obtain sterile substrates and eliminated the influence of epiphytic microorganism on forages.High throughput sequencing was used to monitor the reconstitution mechanism of exogenous microbiota on the same substrate and their contributions on fermentation quality and microbial community during the forage of ensiling.The difference in fermentation quality between legume and grass were analyzed from the view of microbiology.It also provides a theoretical basis for regulating the silage fermentation in practical production.1 Effect of microbiota derived from Italian ryegrass and red clover on fermentation quality and microbial community structure in alfalfa silageThe research was conducted to reveal the effects of Italian ryegrass（IR）and red clover（RC）microbiota on fermentation quality and microbial community dynamics during the ensiling of alfalfa（AL）.Italian ryegrass was treated with the following:y-ray irradiation AL（STAL）,untreated alfalfa（ALNF）,y-ray radiation AL+IR microbiota（ALIR）,y-ray radiation AL+RC microbiota（ALRC）.The fermentation products and microbial community structure in alfalfa silage were significantly affected by the IR and RC microbiota.The ALIR group had higher lactic acid content,ratio of lactic acid to acetic acid and lower pH than those of ALNF group during ensiling.The higher acetic acid and ammonia nitrogen contents were observed in ALRC group compared with ALIR group.Lactobacillus and Enterococcus were dominant in ALNF group at 3 d.Lactobacillus,Enterococcus,Weissella and Lactococcus became the predominant genus in ALIR at 3 d.Hafnia-Obesumbacterium and Pedicoccus were dominant in ALRC group at 3 d.After 60 days of ensiling,Lactobacillus promptly became prevailing the genus in ALIR.Lactobacillus,Enterobacteriaceae and Weissella comprised the multitude of microbial community in ALNF group.In ALRC group,Pediococcus,Lactobacillus,and Hafnia-Obesumbacterium were dominant.The IR and RC microbiota could promote the transformation of alfalfa silage from acetic acid fermentation to lactic acid fermentation.Results suggested that the fermentation characteristics of alfalfa could be controlled through manipulation of the fermentation-associated microbiota.2 Effect of microbiota derived from Italian ryegrass and alfalfa on fermentation quality and microbial community structure in red clover silageThe research was conducted to reveal the effects of Italian ryegrass（IR）and alfalfa（AL）microbiota on fermentation quality and microbial community structure during the ensiling of red clover（RC）.Red clover was treated with the following:y-ray irradiation RC（STRC）,untreated red clover（RCNF）,y-ray radiation RC+IR microbiota（RCIR）,y-ray radiation RC+AL microbiota（RCAL）.The fermentation products and microbial community structure in alfalfa silage were significantly affected by the IR and RC microbiota.The RCIR had highest lactic acid,acetic acid contents and lowest pH than those of RCNF and RCAL during ensiling.After 60 days of ensiling,the highest pH,ammonia nitrogen content and ratio of lactic acid to acetic acid were observed in RCNF.The highest ethanol content was observed in RCAL.Lactococcus and Lactobacillus were dominant in RCNF group at 3 d.Lactobacillus and Weissella became the predominant genus in RCIR group at 3 d.Lactobacillus,Lactococcus and Weissella were dominant in RCAL group at 3 d.Lactobacillus promptly became the predominant genus in RCIR and RCAL groups after 60 days.Lactobacillus,Pediococuss,Lactococcus and Enterococcus comprised the multitude of microbial community in RCNF.Results suggested that IR and AL microbiota could promote the transformation of the microbial community to lactobacillus during red clover ensiling.3 Effect of microbiota derived from oat and red clover on fermentation quality and microbial community structure in Italian ryegrass silageThe research was conducted to reveal the effects of oat（OT）and red clover（RC）microbiota on fermentation quality and microbial community structure during the ensiling of Italian ryegrass（IR）.Italian ryegrass was treated with the following:y-ray irradiation IR（STIR）,untreated Italian ryegrass（IRNF）,y-ray radiation IR+OT microbiota（IROT）,y-ray radiation IR+RC microbiota（IRRC）.The fermentation products and microbial community structure in Italian ryegrass silage were significantly affected by the OT and RC microbiota.The IROT had higher lactic acid content,ratio of lactic acid to acetic acid and lower pH,acetic acid and ammonia nitrogen contents than those of IRNF and IRRC after 60 days.The IRRC had higher pH,acetic acid and ammonia nitrogen contents and lower ratio of lactic acid to acetic acid.After 3 days of ensiling,Lactobacillus,Enterobacteriaceae and Weissella were the dominant microbes in IRNF group.Lactobacillus,Lactococcus and Enterobacteriaceae became the predominant genus in IROT group.Hafnia-Obesumbacterium and Lactococcus were the dominant microbes in IRRC group.Lactobacillus promptly became the dominating genus in IROT group after 60 days.Lactobacillus,Weissella and Enterobacteriaceae comprised the multitude of microbial community in IRNF.In IRRC,Lactobacillus and Hafnia-Obesumbacterium were the dominant microbes.OT microbiota could promote lactic acid fermentation in Italian ryegrass silage;however,the RC microbiota could promote the acetic acid fermentation in Italian ryegrass silage.4 Effect of microbiota derived from Italian ryegrass and red clover on fermentation quality and microbial community structure in oat silageThe research was conducted to reveal the effects of Italian ryegrass（IR）and red clover microbiota（RC）on fermentation quality and microbial community structure during the ensiling of oat（RC）.Oat was treated with the following:y-ray irradiation OT（STOT）,untreated oat（OTNF）,y-ray radiation OT+IR microbiota（OTIR）,y-ray radiation OT+RC microbiota（OTRC）.The fermentation products and microbial community structure in oat silage were significantly affected by the IR and RC microbiota.The higher lactic acid and lower acetic acid contents were observed in OTIR and OTRC groups.The OTIR group had higher ratio of lactic acid to acetic acid and lower pH than those of OTNF and OTRC group.Ammonia nitrogen was significantly increased with red clover microbiota during the ensiling.After 3 days of ensiling,Lactobacillus,Enterobacteriaceae and Lactococcus were dominant in OTNF group.Lactobacillus and Lactococcus became the predominant genus in OTIR group.Hafnia-Obesumbacterium,Lactococcus and Pediococuss were the dominant microbes in OTRC group.After 60 days of ensiling,Lactobacillus and Acetobacter comprised the multitude of microbial community in OTIR group.Lactobacillus,Enterococcus,and Weissella became the predominant genus in OTNF group.In OTRC group,Lactobacillus and Hafnia-Obesumbacterium were the dominant microbes.The IR microbiota could promote the lactic acid fermentation in oat silage. |
