Investigation of the Role of Carbonic Anhydrase in Mineral Formation and Magnesium Incorporation by Bacteria from Qatari Sabkhas and Marine Sediments

Abstract

Mineral-forming bacteria are of great interest in arid environments specifically. These environments are favorable for enhancing the microbial carbonate deposition that is thought to largely influence the sedimentary structure years ago and continue to do so. Qatar’s ecosystem serves as an attractive area for such investigation. In this work, microbial biodiversity in living mats of Dohat Faishakh sabkha was studied using MALDI-TOF mass spectrometry and categorized by identifying characteristic mass peaks and principle component analysis (PCA). Coral sedimentary marine sites were also investigated and carbonate precipitating strains were identified; Vibrio alginolyticus and Psychrobacter sp. The precipitated crystals were examined using SEM/EDS and XRD analysis. This study also investigated 2 enzymatic activities of Carbonic Anhydrase (CA) claimed to be responsible for catalyzing the reversible reaction converting CO2 to HCO3-; esterase and hydration. Both enzymatic assays showed high activity in mineral-forming strains and almost no activity in non-mineral forming bacteria. In this work, it was demonstrated that the presence of an active CA enzyme is strongly correlated to the ability of mineral-forming bacteria to deposit carbonates and incorporate Mg