O'Malley L P, Shaw C H, Collins A N
Arch Biocides, Blackley, Manchester, UK. LO'
J Appl Microbiol. 2007 Oct;103(4):1158-69. doi: 10.1111/j.1365-2672.2007.03354.x.
To isolate micro-organisms capable of utilizing polyhexamethylene biguanide (PHMB) as a sole source of nitrogen, and to demonstrate biodegradation of the biocide.
Two consortia of bacteria were successfully enriched at the expense of PHMB, using sand from PHMB-treated swimming pools as inoculum. Both consortia were shown to contain bacteria belonging to the genera Sphingomonas, Azospirillum and Mesorhizobium. It was shown that the presence of both Sphingomonas and Azospirillum spp. was required for extensive growth of the consortia. In addition, the Sphingomonads were the only isolates capable of growth in axenic cultures dosed with PHMB. Using a stable isotope (15N)-labelled PHMB, metabolism of the biocide by both consortia was demonstrated. By comparing the level of 15N atom incorporation into bacterial DNA after growth on either 15N-PHMB or 15N-labelled NH4Cl, it was possible to estimate the percentage of PHMB biodegradation.
The microbial metabolism of nitrogen from the biguanide moiety of PHMB has been demonstrated. It was revealed that Sphingomonas and Azospirillum spp. are the principal organisms responsible for growth at the expense of PHMB.
This is the first study to demonstrate the microbial metabolism of PHMB.
分离能够以聚六亚甲基双胍（PHMB）作为唯一氮源的微生物，并证明该杀菌剂的生物降解情况。
以经PHMB处理的游泳池中的沙子为接种物，成功富集了两个细菌群落，其生长以消耗PHMB为代价。两个群落均显示含有鞘氨醇单胞菌属、固氮螺菌属和中生根瘤菌属的细菌。结果表明，鞘氨醇单胞菌属和固氮螺菌属的存在都是群落大量生长所必需的。此外，鞘氨醇单胞菌是唯一能够在添加了PHMB的无菌培养物中生长的分离菌株。使用稳定同位素（15N）标记的PHMB，证明了两个群落对该杀菌剂的代谢情况。通过比较在15N-PHMB或15N标记的NH4Cl上生长后15N原子掺入细菌DNA的水平，可以估算出PHMB生物降解的百分比。
已证明PHMB双胍部分中的氮的微生物代谢情况。结果表明，鞘氨醇单胞菌属和固氮螺菌属是消耗PHMB进行生长的主要微生物。
这是第一项证明PHMB微生物代谢的研究。
