活性污泥中细菌对聚丙烯酰胺的生物降解研究

聚丙烯酰胺（Polyacrylamide，PAM）是一类重要的水溶性高分子聚合物，已广泛应用到工农业生产的各个领域和人们的日常生活中。同时，PAM在环境中的残留、迁移和降解对环境的污染也日趋严重，尤其是降解后的单体丙烯酰胺对人类的神经系统有很大的危害。本文从胜利油田的活性污泥中筛选出3株聚丙烯酰胺降解菌，通过比较筛选出一株降解效果较好的菌，命名为AS－2。根据生理生化特性分析，初步鉴定为海球菌属。采用室内培养方法，研究了AS－2对聚丙烯酰胺生物降解的最佳条件。结果表明，当降解时间为5d，pH=8，温度为40℃，碳源为原油，氮源为NaNO3，原油和NaNO3的含量分别为2．5，1．4g·L^-1时，AS-2对聚丙烯酰胺的降解率达到45．23％。通过对聚丙烯酰胺生物降解前后的红外谱图比较，推断出AS-2主要降解了聚丙烯酰胺侧链的酰胺基，将酰胺基降解为羧酸和游离的氡基。用高效液相色谱检测生化后的PAM溶液，未检测出单体丙烯酰胺。

Biodegradation of Polyacrylamide by Bacteria Isolated from Sewage Sludge

Polyacrylamide （ PAM ） is a group of water-soluble high-molecular polymer and has been widely applied in different fields of industry, agriculture and peoples＇ daily life. At the same time, the remain, migration and degradation of PAM are potentially dangerous to environment. Especially, the acrylamide monomer produced from polyacrylamide degradation is harmful to nervous system of human. In this paper, three strain bacteria which degraded polyacrylamide were screened from activated sludge of Shengli Oilfield. One of the three strains, which could degrade polyacrylamide efficiently, named AS-2. According to its physiological and biochemical characteristics, AS-2 bacterium was identified as Marinococcus Genus sp. The optimal conditions for degradation of PAM by AS-2 were obtained as follows：the degradation time was 5 days, the initial pH value was 4, the temperature was 40℃, the carbon source was crude oil and its content was 2.5g·L^-1, the optimal nitrogen source was NaNO3 and its content was 1.4 g·L^-1 . Under the above conditions, the removal ratio of PAM was 45.23%. Tire side chain of PAM was mainly degraded by AS-2 through analyzing the IR spectra of PAM before and after biodegradation. Amido in the side chain of PAM was degraded into carboxylic acid and free amino nitrogen. The acrylamide monomer was not detected in PAM solution after biodegradation by high performance liquid chromatography（ HPLC ）.