Resumen de Heterologously expressed carbonic anhydrase from bacillus mucilaginosus promoting CaCO3 formation by capturing atmospheric CO2
Carbonic anhydrase (CA) can catalyse the reversible hydration of CO2. However, whether the single CA of Bacillus mucilaginosus is helpful to the capture of CO2 and the induction of CaCO3 formation is still ambiguous. To answer that question and foster a better understanding of the function of CAs in bio-geological processes, we cloned five CA genes of B. mucilaginosus into Escherichia coli to form engineering bacteria. Heterologously expressed CA (CA4) was used to test whether or not it can promote carbonate formation with CaCl2 and CO2 as the substrates. Experimental results showed that CA4 can help crystal formation in a relatively short period of time. EDS data confirmed that these crystals are CaCO3. It suggests that CO2 may be more easily captured by CA. Moreover, the differences were significant in both the size and morphology of CaCO3 crystals between treatments with or without CA. The results provide new insights into carbonate-induced synthesis by microorganisms.
