Enrichment and characterization of a highly efficient tetrahydrofuran-degrading bacterial culture.

Abstract

Tetrahydrofuran (THF) is a ubiquitous toxic and carcinogenic pollutant. Screening for pure or mixed-culture microorganisms that can efficiently degrade THF is difficult due to its chemical stability. In this study, an enrichment culture, H-1, with a stable THF-degrading ability and microbial community structure was enriched from activated sludge and could efficiently degrade 95% of 40mM THF within 6days. The optimal THF degradation conditions for H-1 were an initial pH of 7.0-8.0 and a temperature of 30°C. The substrate tolerance concentration of H-1 reached 200mM. Heavy metals tolerance concentrations of Cu2+, Cd2+ and Pb2+ of H-1 was 0.5mM, 0.4mM and 0.03mM, and 4mM Mn2+ did not significantly influence the THF degradation ratio or biomass of H-1. H-1 might be a good material for actual wastewater treatment because of its efficient THF degradation performance and ability to resist various stressful conditions. In addition, the THF-degrading efficiency of H-1 was enhanced by the addition of moderate carbon sources. High-throughput sequencing of the 16S rRNA gene showed that Rhodococcus sp. (a potential THF-degrading strain) and Hydrogenophaga sp. (a potential non-THF-degrading strain) were the dominant microorganisms in the H-1 culture. These results indicate the potential coexistence of cooperation and competition between THF-degrading bacteria and nondegrading bacteria in this enrichment culture.