Hydrogen sulfide oxidation under anoxic conditions by a nitrate-reducing, sulfide-oxidizing bacterium isolated from the Mae Um Long Luang hot spring, Thailand

• Published in: International biodeterioration & biodegradation Vol. 124; pp. 196 - 205
• Main Authors: Watsuntorn, Wannapawn, Ruangchainikom, Chalermchai, Rene, Eldon R., Lens, Piet N.L., Chulalaksananukul, Warawut
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01.10.2017; Elsevier BV
• Subjects: Anoxic biodegradation; Anoxic conditions; Biodegradation; Hydrogen sulfide; Hydrogen sulfide removal; Kinetics; NR-SOB; Nucleotide sequence; Oxidation; pH effects; rRNA 16S; Sodium chloride; SoxB protein; Strain; Sulfide; Thailand; Anoxic biodegradation; Kinetics; Hydrogen sulfide removal; NR-SOB
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/j.ibiod.2017.06.013

Biological removal of hydrogen sulfide (H2S) has been widely practiced across the world because it overcomes the drawbacks associated with physico-chemical processes. In this study, the role of a novel MAL 1HM19 strain of a nitrate-reducing, sulfide-oxidizing bacterium (NR-SOB) isolated from the Mae Um Long Luang hot spring (Thailand) was investigated in batch systems for H2S removal under different initial N-NO3− concentrations (60, 120 and 240 mg N-NO3−/L) at 35 °C. The strain MAL 1HM19 was capable of removing 100% of the gas-phase H2S within 10 h of incubation. In the liquid-phase, the final products depended on the initial N-NO3− concentration: at 120 and 240 mg N-NO3−/L, 15% and 18% SO42− formation was detected, while no SO42− was detected at an initial N-NO3− concentration of 60 mg N-NO3−/L. The identification of strain MAL 1HM19, based on the 16S rDNA nucleotide sequence, revealed it was closely related to Paracoccus sp. (99.93% similarity). The soxB gene was present in strain MAL 1HM19. In addition, strain MAL 1HM19 showed a good capacity to grow at several NaCl concentrations (0.03–7% w/v), at temperatures varying between 20 and 50 °C and within the pH range of 7.0–9.0. [Display omitted] •100% H2S was removed completely within 10 h by strain MAL 1HM19.•The end-products via H2S oxidation relied on the initial nitrate concentration.•Strain MAL 1HM19 is closely related to Paracoccus sp. (99.93% similarity).•soxB gene was detected in strain MAL 1HM19.•MAL 1HM19 tolerated high NaCl concentrations, pH 7.0–9.0 and temperatures 20–50 °C.