铜绿假单胞菌NY3及突变株代谢油污泥同步产胞外聚合物的特性

油污泥属危险性固体废弃物,大量排放已成为石化企业可持续发展的障碍。利用铜绿假单胞菌NY3及突变株,将油污泥转化为生物质,并研究了其特性。研究表明,NY3、NB1D、 NB2D及NB12DD均能降解油污泥中烷烃,但NY3、NB1D和NB2D菌对分子量较高烷烃(从C17~C32)的降解率比双突变菌NB12DD分别平均提高19.68%、28.76%和24.04%。铜绿假单胞菌NY3及突变株能直接将油污泥中烃类转化为胞外聚合物。与未加共代谢碳源相比,葡萄糖作为共代谢碳源时(培养液中表观油浓度达15 g·L-1),培养120 h后,NY3 、NB1D、NB2D、NB12DD菌胞外聚合物产量分别提高83.3%、79.8%、20.6%和62.9%,且碱性条件有利于各菌株高效降解油转化为生物质,pH为8~9时,其胞外聚合物产量均最高,分别达到8.1、4.34、4.94和7.15 g·L-1,野生菌NY3转化碳源为生物质转化率最高,为52.75%。结构和组成分析表明,胞外聚合物主要为糖蛋白,蛋白4.4%,总糖44.1%,蛋白与糖的连接方式为O-糖苷键链接,91.1%大分子粒径分布在33.0~716.9 μm范围。

Characterizations of degradation of oil sludge and synchronous production of extracellular polymers by Pseudomonas aeruginosa NY3 and its mutants

Massive discharge of oil sludge(a hazardous solid waste) has become an obstacle for the sustainable development of petrochemical enterprises.In this study,the decomposition and transformation of oil sludge into microbial extracellular polymers by Pseudomonas aeruginosa NY3 and its genetic mutants were characterized.Alkanes in oil sludge could be degraded by P.aeruginosa NY3 and its genetic mutants.The average degradation rates of high-molecular-weight alkanes(from C17 to C32) by strain NY3,NB1D(alkB1 mutant),and NB2D(alkB2 mutant) were 19.68%,28.76%,and 24.04% higher than that of strain NB12DD(a double alkB1 and alkB2 mutant).During degradation,the four strains transformed the oil sludge into extracellular polymers.The oil sludge(15 g·L-1) was the main carbon source,and glucose that was supplemented as a co-metabolic carbon improved the production of extracellular polymers by approximately 83.3%,79.8%,20.6%,and 62.9% during the 120 h incubation period for strain NY3,NB1D,NB2D,and NB12DD,respectively.For pH 8 to 9 and glucose as a co-metabolic carbon source,the highest yields of the extracellular polymer secreted by the strains were 8.1,4.34,4.94,and 7.15 g·L-1,respectively.The transformation rate of the carbon source by the wild-type strain NY3 was 52.75%.Additionally,the secreted polymer was composed of approximately 4.4% proteins and 44.1% sugars,which were connected by O-glycoside bonds.With respect to polymer molecular size,91.1% were in the range of 33.0 to 716.9 μm.