The Change Of Microorganism Community In Piggery Waster Composting And The Isolation And Identification Of Bacillus

With the rapid development of animal husbandry,a lot of animal manure has become the source of environment pollution and prohibited the stable development of animal raise.Animal manure is rich of fertility,if we handle it in a scientific method,we can not only control the pollution but also make use of it.Among the methods to handle animal manure,aerobic composting is the main method in use.Because of its advantage of economy,simplify,aerobic composting has become more popular in the field of handing animal manure.According to the Pile composting system's principle,we mixed fresh piggery wastes and adjuvant which contained saw-dust and rice-bran in the Huazhong agricultural university pig farm.Because fermentation is the process of biology transform which is performed by the related microbe community,Microbial dynamics of microbial community during the composting process was investigated with the methods of denaturing gradient gel electrophoresis(DGGE) and plating in this trial.The compost results showed that the most microorganism count was bacterium,the second was actinomycete,and the least was fungi.Fungi included yeast and mold.At the same time,the count of the thermophilic microorganism was always less than that of the mesophilic during the composting process.The count of mesophilic microorganism at later stage was less than that at the initial stage.And also the count of thermophilic antinomycete and fungi at later stage were less than that at initial stage.However the count of thermophilic bacterium was stable throughout the composting process.The bands pattern of DGGE and professional quantity one analyses indicated that:the genera of Bacillus,Clostridium and Ureibacillus were dominant species at initial stage; Clostridium,Bacillus and Pseudomonas were dominant species at middle and later stage. Moreover,Clostridium,Bacillus and Pseudomonas were found throughout the process. We also found the different adjuvant in composting has no influence on microorganism community.The variance curve of physical and chemical parameters indicated that the two piles had experienced an integrity course of fermentation in composting prophase, while the results of DGGE detection manifested that the microorganism populations, composed of bacterial,changed greatly.The number of bacterial groups descended in the 0～30 days composting process.I took the basic research of dominant species in composting pile,including isolating,purifying,screening,counting and 16S rRNA identifying.The 16S rRNA identification became the most important molecule method and technology in bacterial identification which has based on the genetic information in procaryotic ribosome small subunit.I got 7 Bacillus strains in saw-dust and rice-bran composting piles.Through the colony characteristics,physiological and biochemical identification,and the hydrolytic test with the spices of organic molecular-starch,protein,cellulose,and fat.I chose 4 trains which had powerful ability to degrade macromolecular,and the results of 16S rRNA identification indicated they were Bacillus thuringiensis,Bacillus cereus, Bacillus megaterium,Bacillus subtilis.Those strains not only were dominant species in composting but also have great activity.We hope that these strains could make up serials biological preparation and inocula which have efficiency to shorten composting cycle and raise the composting quality in future.