The aim of this study was to investigate the potential for elemental sulphur recovery from sulphurous solutions under aerobic and anoxic conditions by haloalkalophilic Thioalkalivibrio denitrificans at 0.8-19.6 g S2O32--S L-1 and 0.2-0.58 g NO2 L-1, respectively. The experiments were conducted as batch assays with haloalkaline (pH 10 and >= 14 g Na+ L-1) thiosulphate solution. Aerobically, the highest biotransformation rate of thiosulphate obtained was 0.03 h(-1) at 8.5 g L S2O32--S. Based on Monod model, the maximum substrate utilisation rate (q(m)) was 0.024 h(-1) with half saturation constant (K-s) 0.42 g S2O32--S L-1 at initial [S2O32--S] of 14 g L-1. S-0 accumulated at [S2O32--S] >= 1.5 g L-1 (10% yield at initial 9.5 g S2O32--S L-1) and the highest S-0 yield estimated with the model was 61% with initial [S2O32--S] of 16.5 g L-1. Anoxically, the maximum nitrite removal rate based on Monod modelling was 0.011 h(-1) with K-s = 0.84 g NO2- L-1. Aerobically and anoxically the maximum specific growth rates (mu(m)) were 0.046 and 0.022 h(-1), respectively. In summary, high-rate aerobic biotransformation kinetics of thiosulphate were demonstrated, whereas the rates were slower and no S-0 accumulated under anoxic conditions. Thus, future developments of biotechnical applications for the recovery of S-0 from haloalkaline streams from the process industry should focus on aerobic treatment.