title: Enrichment, isolation, and characterization of 4-chlorophenol-degrading bacterium Rhizobium sp. 4-CP-20.
abstract: The objectives of this research were to monitor the variations of species in mixed cultures during the enrichment period, isolate species and identify and characterize the pure 4-chlorophenol (4-CP) degrading strains from enriched mixed cultures. Strain Rhizobium sp. 4-CP-20 was isolated from the acclimated mixed culture. The DGGE result indicated that strain Rhizobium sp. 4-CP-20 was undetectable at the beginning but detectable after 2 weeks of enrichment. The optimum growth temperatures for Rhizobium sp. 4-CP-20 were both 36 degrees C using 350 mg l(-1) glucose or sodium acetate as the substrate. The optimum pH range for degrading 100 mg l(-1) 4-CP was between 6.89 and 8.20. Strain Rhizobium sp. 4-CP-20 could degrade 4-CP completely within 3.95 days, as the initial 4-CP concentration was 100 mg l(-1). If the initial 4-CP concentration was higher than 240 mg l(-1), the growth of bacterial cells and the activity of degrading 4-CP were both inhibited.
authors.affiliation: Department of Environmental Engineering, National Chung Hsing University, Taichung 402, Taiwan. maine_ycf@yahoo.com.tw
authors.forename: Chu-Fang
authors.initials: CF
authors.lastname: Yang
authors.forename: Chi-Mei
authors.initials: CM
authors.lastname: Lee
mesh_terms: D002733:Chlorophenols / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012231:Rhizobium / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D002733:Chlorophenols; D012336:RNA, Ribosomal, 16S