Life Sciences & Biotechnology
Title : | Extracellular electron transfer (EET) in extremophiles: Unraveling the EET pathway of a metabolically versatile novel haloalkaliphilic Geoalkalibacter halelectricus strain capable of respiring on insoluble electron acceptors |
Area of research : | Life Sciences & Biotechnology |
Focus area : | Microbial Electron Transfer, Extremophiles |
Principal Investigator : | Dr. Sunil Anil Patil, Indian Institute Of Science Education And Research (IISER) Mohali, Punjab |
Timeline Start Year : | 2023 |
Timeline End Year : | 2026 |
Contact info : | sunil@iisermohali.ac.in |
Details
Executive Summary : | Electromicrobiology pertains to studying microorganisms capable of respiring on insoluble or solid-state electron donors or acceptors via extracellular electron transfer (EET). The EET-capable microbes are known as electroactive microorganisms (EAMs). EAMs play key roles in the biogeochemical cycling of various minerals and direct interspecies electron transfer in natural environments and are exploited as catalysts in microbial electrochemical technologies (METs) such as microbial fuel and electrolysis cells for energy-efficient wastewater treatment and chemicals production besides bioelectronics and biosensing applications. Understanding the EET pathways of microorganisms is crucial to advancing the electromicrobiology discipline and improving microbial EET-based biotechnologies. The EET pathways have been well studied for two microbes, namely Shewanella oneidensis and Geobacter sulfurreducens, which are inhabitants of non-extreme habitats. The EAMs from extreme habitats are of immense interest for understanding their unique lifestyle and use in niche-specific applications. However, they are scarcely explored, and importantly, understanding their EET components and pathways has been barely attempted. Recently, our lab isolated a novel metabolically-versatile strict anaerobic gram-negative EET-capable bacterium named Geoalkalibacter halelectricus SAP-1 from a highly saline-alkaline environment in a SERB-SRG project. Its electrochemical characterization revealed two redox-active moieties with a high positive reduction potential of ~0.386 and 0.570 V (vs. SHE) putatively involved in respiration on the insoluble electron acceptor via direct EET. Redox-active components or cytochromes with such a high formal potential have not been reported for any known EAMs. Based on these experimental observations, I hypothesize the presence of novel membrane components and EET pathway in haloalkaliphilic Geoalkalibacter halelectricus. To test this hypothesis, I propose a multidisciplinary experimental approach involving tools and techniques from anaerobic microbiology, molecular biology, bioinformatics, analytical science, and electrochemistry. It will involve the identification of EET-relevant genetic markers followed by a detailed characterization of the membrane proteins involved in EET. First, the strain will be cultivated with various soluble and insoluble electron acceptors, followed by annotating the whole genome for various metabolic processes and subsystems, particularly for respiration and electron transport components. The target genes will be cloned and amplified in a suitable model organism to overexpress the desired proteins. Finally, the proteins will be isolated and purified through chromatography procedures and characterized through mass spectroscopy and sequencing techniques. Based on this understanding, the ultimate aim is to propose an EET pathway in G. halelectricus and establish it as a model strain for studying EET in extreme microbes. |
Total Budget (INR): | 71,45,339 |
Organizations involved