The Relationship Between The Degradation Of Synthetic Musk And Microbial Community Succession In Sludge Composting

Polycyclic musk, especially galaxolide (HHCB) and tonalide (AHTN) musk, are widespread used as fragrance materials in detergent, soap, cosmetic, perfume, shampoo, body lotion, personal care products, etc. These compounds enter domestic sewage after application. A small amount of polycyclic musk is degradated by microbial oxidation. Researchers in environmental field have detected synthetic musk in almost every apartment of environmental, such as surface water, seawater, sediment, air, biota samples, human adipose tissues, blood and breast milk. The study of the extraction and quantification of PCMs is universally, but microbial degradation rarely. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) based on16S rDNA sequence is widely used to analyze the microbial diversity in activated sludge compost and discuss the relationship between the succession of microbial community and the PCMs degradation of the composting. The main cotext is as follows:1. In this paper, on the basis of consult lots of reports, this study built three groups of properly river sludge composting system in which the microbe could reproduce smoothly, and we found a much suitable external condition for the propagation of microorganisms. Straw mixture and sludge’s volume cooperation ration were2:1. Initial moisture content of piles was maintained to55%-60%during the composting. When PH is6.7and C/N is30.59, the composting fermentation could work normally. The bacterium agent was used as the auxiliary organic materials in the river sludge composting experiment, and in which time-temperature control windrow method composting process was adopted. Three trial groups were set respectively, composting process of about15days and recording the compost temperature everyday. Approximately15g composting sample should be collected on time, which was used to measure the concentration of HHCB and AHTN, and another approximaterly1g composting sample should be frozen at-20℃, which was used to extract microbial DNA and PCR-DGGE. After15days, the compost reached maturity and set a comlete conventional fermentation composting process.2. Used microwave-assisted extraction method to extract musk of the sludge sample after they were dried at room temperature and pulverized to60mesh sieve and use gas chromatography-mass spectrometry (GC-MS) to analyze the HHCB and AHTN concentrations of the sludge.3. Used E.Z.N.ATM Soil DNA Kit to extract microbial DNA of the frozen sludge sample and used PCR-DGGE printing techniques and Quantity one software to analyze the structure of the microbial communities, and then studied the reproduce rule of the microbe with the analytic method and the mathematic method, trying to learn the microbe’s ecological characteristic which could be the reference for the study of how to improve the composting course. Using the biological technique of Denaturing Gradient Gel Electrophoresis understands the development and variation of the microbial structures during the composting, the relationship between the succession of microbial communities and the degradation of HHCB and AHTN, further studies the mechanism of thermopile fermentation during sludge composting. The experiment aims to find microbial community that may degrade polycyclic musk, and it is significance to understand the mechanism of degradation and the transformation pathway of synthetic musk.