Biomimetic Sequestration of CO2 Using Carbonic Anhydrase from Calcite Encrust Forming Marine Actinomycetes

Abstract

Background: CO 2 in the environment has been a burning issue and aggravated the threats of global warming. Various strategies are being used to decrease the level of releasing CO 2 . Biosequestration is a one of the available nontoxic, robust and eco-friendly approaches but still less evaluated. This study reports the role of microbial Carbonic Anhydrase (CA) in the formation of calcite by utilizing CO 2 . Methods: The marine Nocardiopsis lucentensis was studied for intracellular microbial CA. Isolate grown optimally at 2.5% CO 2 saturated environment and procedure the calcium carbonate encrust in the presence of CaCl 2 . Results: The enzyme was found to catalyze the reaction in a wide range of pH and temperature with an optimum at 7.0 pH and 25°C. The 50 mM NaCl, KCl and MgCl 2 were found to support the enzyme activity and 50 mM ZnCl 2 increases activity 1.5 fold. CA was able to withstand against sulphanilamide inhibitor and stable over prolonged incubation at 4 and 37°C. Conclusion: Calcite formation was evaluated with and without enzyme using marine water as a source of calcium ions. The result of SEM and EDX indicated the formation of larger flower-shaped particles compare to the small cubic particles formed without enzyme. The results suggest that the robustness of enzyme and suitability in the CO 2 capture reactor.

Biomineralization of calcium carbonate by marine bacterial strains isolated from calcareous deposits

“…Using p-NPA as a colour indicator during its hydrolysis, we have determined that all isolated marine strains could exhibit carbonic anhydrase activity. This later has been found to have a great potential for production of carbonates [20,21]. Carbonic anhydrase is a major enzyme that plays an important role in carbon concentrating mechanism and sequestration of CO 2 into calcium carbonate [29].…”

“…À and H + , which under certain conditions can capture atmospheric CO 2 [20,21]. In the context of coastal protection, our purpose is to design ecomaterials that mimic naturally-formed rock structures at the seaside and to accelerate their growth kinetics by coupling electrochemical processes with microbial mechanisms of biomineralization.…”

New Biocalcifying Marine Bacterial Strains Isolated from Calcareous Deposits and Immediate Surroundings

“…Bacteria produce enzymes belonging to three distinct classes of CA, α, β, and γ, which have no significant sequence or structural identity [69]. CA are major enzymes that play a significant role in the carbon-concentrating mechanism and sequestration of CO 2 into calcium carbonate [70][71][72]. It has been reported that this enzyme alone can accelerate the rate of CaCO 3 formation by releasing carbonate and bicarbonate ions in large quantities [73,74].…”

Nanoscale Construction Biotechnology for Cementitious Materials: A Prospectus

“…To remove CO 2 , MICP that converts CO 2 into carbonate minerals has been shown to be an effective method (Anbu et al, 2016). As a safe and environment-friendly technique, carbonicanhydrase-enzyme mediated MICP catalyzes reversible hydration of CO 2 to formations of bicarbonates and calcite crystals (Liu et al, 2005;Kim et al, 2012). The carbonic anhydrase enzyme when purified deposits 15 times more carbonates than its crude counterpart (i.e., cells washed and resuspended in lysis buffer) (Ramanan et al, 2009).…”