Annual Research & Review in Biology

This study aimed to isolate and identify a novel bacterial isolate potential resistant to Mn²⁺ as well as to investigate the biosorption isotherms of Mn²⁺ removal from aqueous solutions by the freeze-dried biomass of this bacterium. Sixty three manganese resistant bacterial isolates were recovered from 20 industrial wastewater samples. Interestingly, among them, the isolate number 2120 was able to resist up to 140 ppm of Mn²⁺ and was selected for the further processes. This isolate was phenotypically characterized and identified by 16S rRNA gene sequencing as Proteus penneri and assigned accession number KY712431 in the GenBank database. The effects of pH and contact time on the biosorption process were studied and optimum pH for biosorption equilibrium was 6 while the optimum contact time was 30 min at room temperature. The maximum adsorption capacity (q_max) of Mn²⁺ removal from aqueous solutions by the freeze-dried biomass of Proteus penneri 2120 was 175.4 mg/g. According to Freundlich and Langmuir models, the correlation coefficients (R²) were 0.9977 and 0.5525, respectively. Therefore the studied biosorption isotherms are fit well with Freundlich model rather than the Langmuir model. Our findings suggest that the dried biomass of the isolate Proteus penneri 2120 is potentially applicable for manganese metal ion removal from the industrial waste water.