Anindita Hazarika, Chinmoy Bhuyan, Meera Yadav *

https://doi.org/10.1016/j.bcab.2023.102855

CO₂ the main cause of global warming is a topic of concern for present as well as future generations. For mitigating CO₂, various on-site and off-site carbon capture, and sequestration processes are used. Majority of research is focused on non-biological techniques such geological sequestration, deep ocean sequestration, and pre/post-combustion. However, due to environmental restrictions and related high operational costs, the adoption of non-biological methods for CO₂ reduction is limited. To replace such methods of CO₂ mitigation, sequestration of CO₂ into mineral carbonates by mineralization is a permanent and safe method of storing CO₂. CO₂ sequestration by biomineralization has certain advantages over other existing methods but there are limitations as well. One such limitation is that it is very slow in ambient conditions. The enzymatic method for CO₂ sequestration by carbonic anhydrase, CA is very promising. Keeping these points in view, the present work lead to the investigation of a new source of CA from Azadirachta indica (Neem) leaves. The work focuses on determining the CO₂ sequestration efficiency of both free Neem CA and immobilized Neem CA through CaCO₃ precipitation. The precipitation reaction was faster in the presence of Neem CA. From the results it was quite notable that both free and immobilized Neem leaves CA acted as efficient catalyst in CaCO₃ precipitation.

The reported method of CO₂ sequestration is more affordable, sustainable, and environmental friendly than other methods. In the process of converting CO₂ into carbonate minerals, CA has emerged as an effective biocatalyst. Research work are being initiated in this area, and thus making it an intriguing research topic for future researchers.

*Corresponding Author, Dept. of Chemistry, NERIST, Nirjuli, Itanagar-791109 (AR)