Isolation and Identification of a Manganese-Oxidizing Bacterium from Produced Water: Growth and Manganese-Oxidation Ability of Bacillus zhangzhouensis in Different Manganese Concentrations

Manganese-oxidizing bacteria (MOB) may be found in produced water (PW) due to its manganese (Mn) content and may survive by oxidizing Mn. Additionally, different Mn concentrations can alter the growth of MOB, their growth phases, and their ability to produce MnOx. To investigate these aspects, the presence of MOB was investigated in PW. The MOB isolate was identified by molecular and biochemical methods. Its ability to oxidize Mn was also evaluated using Mn-oxidation agar medium with different Mn concentrations (0.15, 0.5, 1, 2, and 3 g/L). The strain was identified as Bacillus zhangzhouensis. The results showed that the Mn concentrations affected both the strain's growth and its ability to oxidize Mn. Triauxic growth was observed at the concentrations of 0.5 g/L and 1 g/L where the bacterium showed the most intensive growth and Mn-oxidation. In contrast, the concentrations of 2 and 3 g/L inhibited bacterial growth. This is the first study reporting the isolation of Mn-oxidizing B. zhangzhouensis from oil environment. The oil industry should consider the presence of this bacterium as it might be a potential risk for microbiologically influenced corrosion.