Use of a glass bead-containing liquid medium for efficient production of a soil-free culture with polychlorinated biphenyl-dechlorination activity

Abstract

We established a soil-free culture capable of dechlorinating polychlorinated biphenyls (PCBs) in Kanechlor-300 and Kanechlor-400 by establishing a PCB-dechlorinating soil culture in liquid medium containing 0.5 mm glass beads. PCB-dechlorination activity in liquid cultures with glass beads appeared to depend on the size of the glass beads, and soil-free cultures with 0.05-, 1.0- or 2.0 mm glass beads did not dechlorinate PCBs. Soil-free culture without glass beads also failed to dechlorinate PCBs. The soil-free culture containing 0.5 mm glass beads dechlorinated 42.6 ± 12.0 mol% in total PCBs. This soil-free culture was more effective than soil culture for dechlorinating PCBs ranging from dichlorinated PCBs to tetrachlorinated PCBs. Clone analysis of the 16S rRNA gene sequences showed that one of the predominant groups of microorganisms in the soil-free culture comprised heat-tolerant and spore-forming bacteria from the phylum Firmicutes. Heat treatment (100 °C, 10 min) did not destroy the PCB-dechlorination activity of the soil-free culture with glass beads. These results suggest that unknown species of the phylum Firmicutes were involved in PCB dechlorination in the soil-free culture. In this study, we succeeded in using a liquid medium containing glass beads as an inorganic soil substitute and showed that such a medium enhances PCB-dechlorination activity. Our study provides valuable information for developing PCB-bioremediation techniques using dechlorinating bacteria in anoxic contaminated soils and sediments.

Atrazine biodegradation efficiency, metabolite detection, and trzD gene expression by enrichment bacterial cultures from agricultural soil

“…Prolonged exposure of microbial communities to the xenobiotic compounds facilitated the biodegradation and thereby reduced toxicity in the contaminated sites (Zhang et al, 2011;Ganesh-Kumar et al, 2013;Suzuki et al, 2013) and applications of sustainable The tree was constructed with Trabulsiella guamensis as an out group and the tree topology was analyzed by parsimony analysis (DNAPARS) with bootstrapping over 1000 replicates using PHYLIP package. Scale bar 0.01 represents the nucleotide substitution level at 0.01% and economically feasible various remediation technologies maintain the quality of soils and waters (Lone et al, 2008).…”

Considering ecosystem modeling by examining the creation of microcosms for Daphnia coexistence using an inorganic medium

“…In addition, 16s rRNA gene sequencing analysis showed the presence of species different from the previously reported PCB-degrading bacteria. Furthermore, the degradation activity remained unchanged even after heating to 100°C, suggesting that the constituent species of the GB0.5 mm culture are formed from species that are not yet well known (Suzuki 2013). Based on these results and the results of the preliminary experiments, spaces constructed by particles with diameters from ≥ 0.05 mm to ≤ 2 mm are considered suitable spaces for the survival of anaerobic bacteria.…”

Microbial Community and Atrazine-Degrading Genetic Potential in Deep Zones of a Hypersaline Lake-Aquifer System

“…Nowadays, it is known that the acceleration of the biodegradation process is mainly due to the enzymatic-degrading pathway dispersed among a wide range of microorganisms. As a response to prolonged exposure of atrazine, microbial communities might be able to adapt to metabolize the compound, facilitating the biodegradation and thereby reducing toxicity in the contaminated sites [58,59]. The microbial degradation pathways play the primary role in the reduction of toxic chemicals from contaminated aquatic environments.…”