Potential of biological sulphur recovery from thiosulphate by haloalkaliphilic <i>Thioalkalivibrio denitrificans</i>
Creators: name: Hajdu-Rahkama, Réka
name: Özkaya, Bestamin
name: Lakaniemi, Aino-Maija
name: Puhakka, Jaakko A.
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified
subject: Marine Biology
subject: Inorganic Chemistry
subject: Science Policy
subject: Computational Biology

description: The aim of this study was to investigate the potential for elemental sulphur recovery from sulphurous solutions under aerobic and anoxic conditions by haloalkalophilic <i>Thioalkalivibrio denitrificans</i> at 0.8–19.6 g S<sub>2</sub>O<sub>3</sub><sup>2−</sup>-S L<sup>−1</sup> and 0.2–0.58 g NO<sub>2</sub> L<sup>−1</sup>, respectively. The experiments were conducted as batch assays with haloalkaline (pH 10 and ≥ 14 g Na<sup>+</sup> L<sup>−1</sup>) thiosulphate solution. Aerobically, the highest biotransformation rate of thiosulphate obtained was 0.03 h<sup>−1</sup> at 8.5 g L S<sub>2</sub>O<sub>3</sub><sup>2−</sup>-S. Based on Monod model, the maximum substrate utilisation rate (q<sub>m</sub>) was 0.024 h<sup>−1</sup> with half saturation constant (K<sub>s</sub>) 0.42 g S<sub>2</sub>O<sub>3</sub><sup>2−</sup>-S L<sup>−1</sup> at initial [S<sub>2</sub>O<sub>3</sub><sup>2-</sup>-S] of 14 g L<sup>−1</sup>. S<sup>0</sup> accumulated at [S<sub>2</sub>O<sub>3</sub><sup>2−</sup>-S] ≥ 1.5 g L<sup>−1</sup> (10% yield at initial 9.5 g S<sub>2</sub>O<sub>3</sub><sup>2−</sup>-S L<sup>−1</sup>) and the highest S<sup>0</sup> yield estimated with the model was 61% with initial [S<sub>2</sub>O<sub>3</sub><sup>2-</sup>-S] of 16.5 g L<sup>−1</sup>. Anoxically, the maximum nitrite removal rate based on Monod modelling was 0.011 h<sup>−1</sup> with K<sub>s </sub>= 0.84 g NO<sub>2</sub><sup>−</sup> L<sup>−1</sup>. Aerobically and anoxically the maximum specific growth rates (µ<sub>m</sub>) were 0.046 and 0.022 h<sup>−1</sup>, respectively. In summary, high-rate aerobic biotransformation kinetics of thiosulphate were demonstrated, whereas the rates were slower and no S<sup>0</sup> accumulated under anoxic conditions. Thus, future developments of biotechnical applications for the recovery of S<sup>0</sup> from haloalkaline streams from the process industry should focus on aerobic treatment. Haloalkaline S<sub>2</sub>O<sub>3</sub><sup>2−</sup> biotransformations kinetics by <i>Thioalkalivibrio denitrificans</i> Aerobic thiosulphate-S bioconversion up to 0.024 h<sup>−1</sup> with K<sub>s</sub> = 0.42 g S<sub>2</sub>O<sub>3</sub><sup>2−</sup>-S L<sup>−1</sup> 10% S<sup>0</sup> yield with initial 9.5 g S<sub>2</sub>O<sub>3</sub><sup>2-</sup>-S L<sup>−1</sup> in aerobic condition Anoxic NO<sub>2</sub> removal up to 0.01 h<sup>−1</sup> with K<sub>s</sub> = 0.84 g NO<sub>2</sub><sup>−</sup> L<sup>−1</sup>