Isolation and Characterization of Novosphingobium sp. Strain MT1, a Dominant Polychlorophenol-Degrading Strain in a Groundwater Bioremediation System

• DOI: 10.1128/aem.68.1.173-180.2002
• Publication Date: 2002-07-27T09:56:57Z
• Authors: Marja A. Tiirola; Minna K. Männistö; Jaakko A. Puhakka; Markku S. Kulomaa
• Keywords: Strain (injury)

ABSTRACT A high-rate fluidized-bed bioreactor has been treating polychlorophenol-contaminated groundwater in southern Finland at 5 to 8°C for over 6 years. We examined the microbial diversity of using three 16S ribosomal DNA (rDNA)-based methods: denaturing gradient gel electrophoresis, length heterogeneity-PCR analysis, and restriction fragment polymorphism analysis. The molecular study revealed that process was dependent on a stable bacterial community with low species diversity. dominant organism, Novosphingobium sp. strain MT1, isolated characterized. MT1 degraded main contaminants groundwater, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, pentachlorophenol, 8°C. carried homolog pcpB gene, coding pentachlorophenol-4-monooxygenase Sphingobium chlorophenolicum . Spontaneous deletion gene resulted loss degradation ability. Phenotypic dimorphism (planktonic sessile phenotypes), growth rate (0.14 0.15 h −1 ), low-copy-number rDNA genes (single copy) were characteristic other MT1-like organisms from bioreactor.