Effects Of Swine Manure Compost With Inoculation Of Different Microorganism Agents And Research On Microbial Community Changes By PCR-DGGE

To research on effects of defferent inoculants used in pig manure,changes of bacterias in compost,and to approach the feasibility of animal microecological bacteria agents used in composting.In this experiment,ascendant microbials were screened from decomposed pig manure and were made into compound bacteria agents.Effects of inoculating different microorganism agents on composting of swine manure and research on microbial community changes by PCR-DGGE were done.Screening from decomposed pig manure compost by using selective plate and high temperature,10 composting microbes were used to making inoculants,3 Bacillus strains which could endure 80℃high temperature and a bacilli,3 Actinomycosis,3 mould and 1 yeast fungus.Complex microorganism agents were made with these metioned above.The agents were inoculated in swine manure by 0.1%respectively,divided into 4 groups:T1 was group of isolated bacterias of compost,T2 was microecological bacteria group,T3 was microecological bacteria too(add a concentration of bacteria one times of the T2),a group without adding bacteria as the control group.The effects of compost was evaluated by determination of index in 30d of composting:temperature,pH,moisture,the entire carbon,nitrogen and C/N.The results showed that:The maximum temperature of T1,T2 and T3 were higher than control group,and sustained period of high-temperature were longer than control group.Time of compost temperature which was above 50℃,T2 and T3 were 23 days which were the longest,T1 for 21 days,while the control group C only 10 days.Water changes of this fout groups were similar trend,with the compost, compost moisture gradually decline,pH value trends were consistent with each group, early were gradually rising trend and later gradually decline.Carbon utilization of T1,T2 and T3 were higher than the control group,at the end of composting,T1 carbon content dropped by 11.88%,T2 dropped by 5.75%,T3 dropped by 12.96%,while the control group only dropped by 4.73%.At the end of composting,C/N of T1 and T3 Group declined the most.When the physical and chemical indicators were integrated considered,the treatment group(T1)which microbial from compost were added was the best,followed by the groups treated addition of animal microecological bacterias(T2 and T3).T2 was better than T3,it showed that how much the addition quantity affected composting effects,but taking into account the actual cost of production,0.1%of bacteria content was feasible.DNA of bacterias in different periods of compost was extracted,and 16 S rDNA V3 District of bacterias were got by PCR amplification.DGGE patterns showed that:the composting process in the quantities and types of bacteria change in the trend was "higher-lower-higher." Initial composting,the flora of composition of each groups were highly similar,93%-100%;compared to other periods of composting,the similarity was only 50%,the flora changes in the control group was faster than inoculated bacterias Groups.In 3-9 days,composition of flora of the control group and the other three groups were very different,the similarity of PCR-DGGE DNA profiles was 68%.The bacteria community of composting changed greatly,when composting was in a high temperature period,dominant flora and flora which tolerate high temperatures appeared in the stage, and some flora which can not tolerate the high temperature would disappear or weakened. In 21-30 days,it was cooling-maturity period of composting,composition of bacteria in compost gradually became stable and the similarity was 93%-100%,the diversity was higher than high-temperature period,the control group with the diversity of the group emerged early than inoculated bacterias groups.As composting experienced warming period,the maintenance of high temperature,cooling down period and the maturity period, the various stages of composting environment adapted to different microbial survival and growth.Initial composting the variety of bacterias were mainly indigenous bacterias which were larger quantities and types,and the presence of pathogens,such as Treponema brennaborense and Escherichia coli which could cause pig dysentery.In high temperature phase,the bands reduced and advantage zone emerged,which was mainly Bacillus sp.The pathogens bands which could detected in the early composting gradually weakened or disappeared.Bands increased in cooling down period also.Microorganisms and bacterias from compost and animal microecological agents were detected in DGGE profiles. Bacillus was correspondence with the predominant band appeared in high-temperature phase,and the existence of the band was longer than the control goup.The results showed that inculated bacterias could adapt to composting environment, and became the predominant flora.They could made composting temperature increased significantly and prolonged the duration of high temperature and reduce the smelly odor of compost,and accelerated the decomposition.Animal microecological agents used in composting were feasible.