(808e) A Green Approach to Mitigate CO2 Using Mixed Microbial Culture

Carbon dioxide is one of the GHG’s (Green House Gases) & responsible for Global warming.. As of July 2011, CO₂ in the earth's atmosphere is at a concentration of 392 ppm by volume which is 35% higher as compared to the mid-1800s. Carbon dioxide, which is estimated to contribute 50-60% of the Global warming in the last century, is majorly released during the combustion of fossil fuel. The CO₂ concentration in earth atmosphere can be reduced by biological, chemical and technological techniques available through either mitigating or sequestering emissions. In the recent years, biological route has been identified as one of the most viable options available for the mitigation of CO₂. There are six carbon fixing pathway’s.  Out of which, the Calvin cycle (Calvin-Benson-Bassham) is used by photoautotroph’s to fix CO₂. There are microbes which are ubiquitous in nature and thrive in extreme environment classified as chemoautotrops. They also classified as Extremophiles. The requirement of industries is to develop a economic, efficient and effective system which not only fix CO₂ but also capable to withstand in the severe industrial environment. Mixed culture is proved to be a superior candidate, as the consortium of different engineered species develop a symbiotic relationship which helps each other not only to survive in harsh conditions but also curb down CO₂. The another possibilities are simultaneous waste water treatment, production of Methane,  and bio-hydrogen production. The present work deals in identification of microbes present in sludge of waste water treatment plant having CO₂ fixation capabilities. It also gives the insight of  the relation which exists between natural selected mixed culture and to understand the capabilities of CO₂ fixation. The batch study has been conducted to measure the capabilities of mixed culture to mitigate CO₂ for five different V/V % concentration of CO₂ 4, 12, 16, 22 and 25. It was observed that CO₂ is completed consumed by microorganisms in 4 days. Mitigation rate for different concentration of CO₂, bio-mass growth rate and resulting product has been analyzed on per hour basis and per day basis. Mixed culture is found to be superior candidate than photoautotrophic organisms for CO₂ mitigation. They show a promising future to develop a low cost, compact size closed system for in-situ CO₂ mitigation.