[Advances in synthesis of polyhydroxyalkanoates by using residual activated sludge]

Pure microbial fermentation is the primary means of polyhydroxyalkanoates (PHA) production at present, but high cost limits its large-scale application. In recent years, the synthesis of PHA by mixed microbial culture of activated sludge has been extensively studied. Combining the residual sludge treatment with PHA synthesis not only eliminates the sterilization process necessary for pure culture, but also utilizes residual sludge as resource. The hydrolysis and acidification of the residual sludge, the enrichment and acclimation of the consortium and the PHA synthesis are affected by environmental factors. The intensive biosynthesis mechanism study is helpful for the application of mixed culture to synthesize PHA. This paper introduces the feasibility of using residual sludge to synthesize PHA, the factors affecting the hydrolysis and acidification of residual sludge, the accumulation and domestication of PHA by sludge microbial consortium and its mechanism.