ABSTRACT
Sub-seafloor methane hydrate deposits have attracted attention in recent times as an enormous and yet untapped source of alternate energy. It is interesting to note that methane in sub-seafloor methane hydrate deposits is of biogenic origin. The sub-seafloor environment is mostly anoxic and characterized by high pressure and the presence of complex organic matter. Microorganisms adapted to such extreme sub-seafloor environmental conditions may serve as source of novel taxa and industrially valuable biomolecules. Microbial metabolism is responsible for the degradation of complex organic matter and subsequent formation of methane. Various ecophysiological and nutrient conditions have a significant influence on the rate of methane formation and on the conversion of methane into methane hydrate deposits. Understanding the kinetics of methanogenesis is of utmost importance in predicting the rate and extent of methane hydrate deposits in sub-seafloor environments. This review illustrates the diversity of anaerobes in deep-sea sediments associated with methane hydrates and their metabolism leading to methane generation.
Subject(s)
Bacteria, Anaerobic/physiology , Geologic Sediments/chemistry , Geologic Sediments/microbiology , Hydrogen/metabolism , Methane/metabolism , Microbial Consortia/physiology , Bacteria, Anaerobic/classification , Bacterial Proteins/metabolism , Hydrogen/chemistry , Methane/chemistry , Microbiota/physiology , Models, Biological , Oceans and Seas , Species SpecificityABSTRACT
Clostridium sulfidigenes 113A is a strictly anaerobic, rod shaped, gram positive bacterium isolated from sub-seafloor sediments associated with methane hydrates. Here, we report the first draft genome of C. sulfidigenes strain 113A, which comprises 3,717,420 bp in 96 contigs with the G+C content of 30.1%. A total of 3148 protein coding sequences were predicted. The genome annotation revealed that 113A could play an important role in biogeochemical cycles and have potential biotechnological applications such as production of organic acids and butanol.
Subject(s)
Clostridium/genetics , Genome Components/genetics , Genome, Bacterial/genetics , Geologic Sediments/microbiology , Base Composition , Base Sequence , Geologic Sediments/chemistry , Methane/analysis , Molecular Sequence Data , Sequence Analysis, DNAABSTRACT
Clostridium celerecrescens 152B is an obligate anaerobic, Gram positive rod shaped bacterium isolated from sub-seafloor methane hydrate sediments of Krishna Godavari basin, India. Here, we report the first draft genome sequence of C. celerecrescens 152B, which comprises 5,050,495bp in 92 contigs with the G+C content of 43.5%. The whole genome of C. celerecrescens 152B was sequenced for further biotechnological exploitation of its genome features especially regarding the production of secondary metabolites as well as for environmental bioremediation and production of industrially valuable enzymes.
Subject(s)
Clostridium/genetics , Genome, Bacterial , Clostridium/classification , Gene Expression Regulation, Bacterial/physiology , Geologic Sediments , Methane , Molecular Sequence DataABSTRACT
Members of the genus Methanoculleus are among the most prevalent methanogens in biomethanation processes especially in marine and brackish environments. A methanogen, identified as a novel species of the genus Methanoculleus, was isolated from deep sub-seafloor sediment obtained from the Krishna Godavari Basin off the eastern coast of India. This methanogen is thought to be the supplier of the methane in the submarine methane hydrate deposits. Further study of this microorganism could possibly help to revolutionize the energy industry. The draft genome of Methanoculleus sp. MH98A is presented.
