Microbial Potential for Carbon Fixation and Stabilization

Research on microbial diversity, interaction between microbes and soil physiochemical properties, role of microbes in biogeochemical cycles, and climate change have guided the scientific community to understand the soil and environmental health. Carbon is one of the essential elements of the soil, oceans, atmosphere, crustal rocks, kerogen (solid hydrocarbon for the formation of fuels), and reserve in various forms called carbon sink. Carbon-containing organic molecules flux between all these ecosystems (reservoirs) for the balance and sustainable function of the ecosystems via active carbon cycle. Carbon is the prime element for building a life on Earth which is fixed in various forms in the terrestrial and marine plants through photosynthesis. Microorganisms play regulatory role in biogeochemical cycles and shaping any kind of ecosystems. There are huge diversity of soil and aquatic microbes like Acetobacterium woodii, Aquifex aeolicus, Archaebacteria brierleyi, Ignicoccus hospitalis, Chlorobium limicola, C. tepidum, C. thiosulfatophilum, C. phaeobacteroides, Chloroflexus aurantiacus, C. aggregans, Chromatium vinosum, Clostridium thermoaceticum, Crenarchaeota, Desulfobacter hydrogenophilus, Desulfurobacterium crinifex, D. thermolithotrophum, Halobacterium salinarum, Thiobacillus ferrooxidans, Hydrogenobacter hydrogenophilus, H. thermophilus, Metallosphaera sedula, Moorella thermoacetica, Pyrobaculum aerophilum, Pyrobaculum islandicum, Pyrolobus fumarii, Rhodobacter sphaeroides, Rhodopseudomonas viridis, Rhodospirillum rubrum, Stygiolobusa zoricus, Sulfolobus metallicus, Sulfurihydrogenibium subterraneum, Thermocrinis ruber, Thermoproteus neutrophilus, Thermovibrio ammonificans, T. ruber, and Thiomicrospira denitrificans, and also order Rhizobiales are able to fix the various forms of carbon through numerous pathways such as Calvin cycle, reductive acetyl-coenzyme A pathway, reductive citric acid cycle, dicarboxylate/4-hydroxybutyrate cycle (DC/HB), hydroxypropionate/4-hydroxybutyrate cycle (HP/HB), and 3-hydroxypropionate bicycle. The fixed carbon is used by these microbes for their growth and development and also to make it available for other organisms. The carbon sequestration efficiency of plants and microbes by biotic (photosynthesis and respiration) processes plays key crucial role in mitigation of global climate change and environmental stability. In spite of the use of modern biotechnologies in research, huge information of microbial diversity and role in balancing of biogeochemical cycle are still not fully known. Therefore, it is crucial to discuss in-depth the scientific knowledge of microbial carbon fixation processes and its role in the mitigation of global climate change in present era.