Efficiently Accumulate PHB Bacteria And Yeast Community Tamed And The Diversity Investigate

Polyhydroxybutyrate (PHB) are natural polyesters that accumulate in numerous microorganisms as intracellular carbon and energy storage materials under nutrient and carbon imbalance conditions. Owing to the mechanical properties of PHB is similar to traditional petrochemical synthesis plastic, While it with the advantage of biodegradable andbiocompatible polyesters and so on. PHB is a novel and friendly material with widely application prospect and potential value. Sewage sludge contains different types of accumulated PHB microbial which way can instead of pure strain produc PHB. Using sewage sludge to produce PHB can decrease the cost. In order to improve the capabilities of synthesizing PHB, We adjust the culture condictions. Additionally, denaturing gradient gel electrophoresis (DGGE) was used to analyze the population dynamic shifts and structural characteristics during the optimization process and culture period.In this study, we used sodium acetate as the single carbon and anaerobic/aerobic (A/O) SBR to domestic the microbial community synthesizing PHB. To help improve PHB production, the culture medium COD increased gradually, simultaneously decreased nitrogen. established imbalance cultured environment.The research results showed that with the concentration of COD increased, but the concentration of nitrogen and phosphorus decreased, the PHB content increased gradually. When the COD increased to1200mg/L, COD/N=80, COD/P=200. PHB accumulation reached to a maximum value is about74.2%of the dry weight. This research results also proved that improved COD concentration, and simultaneously reduced the concentration of nitrogen and phosphorus is an effective way of domestication high efficiently bacteria community. The conceration of COD, nitrogen, phosphorus and PHB were detected in different period to find the dynamic changes of production. There are large amount of white granules PHB intracellular showed by scanning electron microscope.Additionally, PCR-DGGE was used to analyze community diversity and structural. The electrophoresis picture results showed that the diversity of bacteria community is quite rich and structure is complex. Among them16strains were detected they belong to10genera. Zoogloea sp. and Rhizobiales bacterium as dominant species. Many researches showed that Zoogloea sp. and Rhizobiales bacterium with high efficiently synthesis of PHB ability, which maybe the reason why the flora with high-yielding PHB ability. Analyze the main bands of DGGE profiles during the process of domestication and COD1200phase. Research results showed that, the community had high-efficiency synthesis PHB ability, which associated with the Methylobacteriaceae bacterium, Zoogloea sp.， Hydrogenophaga sp. and Rhizobiales bacterium.Compared with the bacteria community, the diversity of the yeast community is relatively simple, respectively belong to Geotrichum klebahnii, Trichosporon montevideense, Candida intermedia, Pichia guilliermondii and Galactomyces Geotrichum five genera, they are the common yeast in sewage treatment system, especially the strain of Candid sp. has been reported with the synthesis of PHB ability, may be associated with PHB synthesis in community.Yeast acid-resistant, resistant to high osmotic pressure, suitable for high COD of wastewater treatment, it could be the reasons of the existence of it in COD1200phase.