Department of Bioenvironmental Engineering and R&D Center for Membrane Technology, Chung Yuan Christian University, Chung-Li 32023, Taiwan.
J Microbiol Biotechnol. 2012 Aug;22(8):1141-7. doi: 10.4014/jmb.1111.11040.
Polyhydroxyalkanoate (PHA) is a class of biodegradable plastics that have great potential applications in the near future. In this study, the micro-biodiversity and productivity of PHA-accumulating bacteria in activated sludge from a domestic wastewater treatment plant were investigated. A previously reported primer set and a selfdesigned primer set (phaCF1BO/phaCR2BO) were both used to amplify the PHA synthase (phaC) gene of isolated colonies. The new primers demonstrated higher sensitivity for phaC, and combining the PCR results of the two primer sets was able to widen the range of detected genera and raise the sensitivity to nearly 90%. Results showed that 85.3% of the identified bacteria were Gram-negative, with Ralstonia as the dominant genus, and 14.7% were Gram-positive. In addition, Zoogloea and Rhizobium contained the highest amounts of intracellular PHA. It is apparent that glucose was a better carbon source than pentone or tryptone for promoting PHA production in Micrococcus. Two different classes, class I and class II, of phaC were detected from alphaproteobacteria, betaproteobacteria, and gammaproteobacteria, indicating the wide diversity of PHA-accumulating bacteria in this particular sampling site. Simultaneous wastewater treatment and PHA production is promising by adopting the high PHAaccumulating bacteria isolated from activated sludge.
聚羟基脂肪酸酯（PHA）是一类可生物降解塑料，具有很大的应用潜力。本研究考察了生活污水处理厂活性污泥中聚羟基脂肪酸酯（PHA）积累菌的微生物多样性和生产力。使用先前报道的引物组和自行设计的引物组（phaCF1BO/phaCR2BO）对分离菌的 PHA 合酶（phaC）基因进行扩增。新引物对 phaC 的灵敏度更高，将两种引物组的 PCR 结果结合使用可以扩大检测属的范围，并将灵敏度提高到近 90%。结果表明，85.3%鉴定出的细菌为革兰氏阴性菌，以罗尔斯通氏菌为优势属，14.7%为革兰氏阳性菌。此外，动胶菌和根瘤菌体内的 PHA 含量最高。很明显，葡萄糖是促进微球菌中 PHA 生产的比戊酮或色氨酸更好的碳源。从α变形菌、β变形菌和γ变形菌中检测到两类 phaC，分别为 I 类和 II 类，表明该特定采样点中 PHA 积累菌具有广泛的多样性。通过采用从活性污泥中分离出的高 PHA 积累菌，可以实现同时处理废水和生产 PHA。
