Vignesh Venkatasamy

Bio: Vignesh Venkatasamy is an academic researcher from Bharathidasan University. The author has contributed to research in topics: Microbial fuel cell & Aerolysin. The author has an hindex of 1, co-authored 2 publications receiving 1 citations. Previous affiliations of Vignesh Venkatasamy include Government of India.

An Overview of Current Trends in Emergence of Nanomaterials for Sustainable Microbial Fuel Cells

Abstract: Microbial fuel cell (MFC) technologies have been globally noticed as one of the most promising sources for alternative renewable energy, due to its capability of transforming the organics in the wastewater directly into electricity through catalytic reactions of microorganisms under anaerobic conditions. In this chapter, the state of the art of review on the various emerging technological aspects of nanotechnology for the development of nanomaterials to make the existing microbial fuel cell technology as more sustainable and reliable in order to serve the growing energy demand. Initially, a brief history of the development and the current trends of the microbial fuel cells along with its basic working mechanism, basic designs, components, fascinating derivative forms, performance evaluation, challenges and synergetic applications have been presented. Then the focus is shifted to the importance of incorporation of the nanomaterials for the sustainable development of MFC technology by means of advancements through anode, cathode, and proton exchange membranes modifications along with the various ultimate doping methods. The possibilities of applied nanomaterials and its derivatives in various places in MFCs are discussed. The nanomaterials in MFCs have a significant contribution to the increased power density, treatment efficiency, durability, and product recovery due to its higher electrochemical surface area phenomenon, depending on the fuel cell components to get modified. The promising research results open the way for the usage of nanomaterials as a prospective material for application and development of sustainable microbial fuel cells. Though the advances in nanomaterials have opened up new promises to overcome several limitations, but challenges still remain for the real-time and large-scale applications. Finally, an outlook for the future development and scaling up of sustainable MFCs with the nanotechnology is presented with some suggestions and limitations.

An In Silico Evaluation of Molecular Interaction Between Antimicrobial Peptide Subtilosin A of Bacillus subtilis with Virulent Proteins of Aeromonas hydrophila

Abstract: Subtilosin A, a cyclic peptide from Bacillus subtilis is known for its antimicrobial activity against a diverse range of bacteria. Herein, we report the specific interaction between subtilosin A against virulent proteins of Aeromonas hydrophila through in silico analysis. Aeromonas toxic proteins such as aerolysin and hemolysin were selected from the non-redundant database. The hemolysin protein was designed by homology modelling tool, and it was validated using Ramachandran plot. Then subtilosin A and target toxin proteins were energy minimized for further docking study. The whole docking experiments were done using antibody mode in Cluspro. Subtilosin A building an active interaction with Aeromonas toxins through H-bonds and protein–protein docking analysis revealed that the hemolysin has 6 H-bond interaction towards the antimicrobial target protein subtilosin A than aerolysin, which has 9 H-bonds. The most favourable interacting residues of subtilosin A are Thr6, Cys13, Ile19, Pro20, Asp21, Phe22, Glu23 and Gly35 involving in the strong H-bond formation and proceeds to inhibition of toxin. Hence, the study confirmed that the subtilosin A has more antimicrobial activity to inhibit the Aeromonas toxins by interacting with their binding site residues for preventing extracellular cleavage.

Electrochemical Losses and Its Role in Power Generation of Microbial Fuel Cells

Abstract: Microbial fuel cells (MFC) is an emergent source of renewable energy technology, where the microbes are incorporated in an electrochemical system with organic loads, for controlled production of electricity from wastewater due to the catalytic action of anode respiring microbes under the anaerobic condition. Considering the redox potential of electrochemical reactions, MFC with oxygen as terminal electron acceptor is capable to produce the potential of 1.2 V theoretically However, in real practice, the obtained voltage from MFC is too low s(500–650 mV) due to various electrochemical losses encountered in the MFC, which further affects the power density. The state of the art review focused in this chapter is on the electrochemical losses related hurdles and its role in power generation in the MFCs, which is limiting this technology to be adopted widely and considerably efficient. Though the power production from MFC is being impelled by various governing aspects such as the selection of microbial strains, substrate conditions, electrodes materials, and operating conditions, researchers have attempted various studies to overcome the electrochemical losses thus making MFCs ideal for real-time applications.

Klebsiella pneumoniae Volatile Organic Compounds (VOCs) Protect Artemia salina from Fish Pathogen Aeromonas sp.: A Combined In Vitro, In Vivo, and In Silico Approach

Abstract: Antibiotic resistance is an alarming threat all over the world, and the biofilm formation efficacy of bacteria is making the situation worse. The antagonistic efficacy of Klebsiella pneumoniae against one of the known fish pathogens, Aeromonas sp., is examined in this study. Moreover, Aeromonas sp.’s biofilm formation ability and in vivo pathogenicity on Artemia salina are also justified here. Firstly, six selected bacterial strains were used to obtain antimicrobial compounds against this pathogenic strain. Among those, Klebsiella pneumoniae, another pathogenic bacterium, surprisingly demonstrated remarkable antagonistic activity against Aeromonas sp. in both in vitro and in vivo assays. The biofilm distrusting potentiality of Klebsiella pneumoniae’s cell-free supernatants (CFSs) was likewise found to be around 56%. Furthermore, the volatile compounds of Klebsiella pneumoniae were identified by GC-MS in order to explore compounds with antibacterial efficacy against Aeromonas sp. through an in silico study, where 5′-methylthioadenosine/S-adenosylhomocysteine nucleosidase (MTAN) (PDB: 5B7P) was chosen as a target protein for its unique characteristics and pathogenicity. Several volatile compounds, such as oxime- methoxy-phenyl-, fluoren-9-ol, 3,6-dimethoxy-9-(2-phenylethynyl)-, and 2H-indol-2-one, 1,3-dihydro- showed a strong binding affinity, with free energy of −6.7, −7.1, and −6.4 Kcal/mol, respectively, in complexes with the protein MTAN. Moreover, the root-mean-square deviation, solvent-accessible surface area, radius of gyration, root-mean-square fluctuations, and hydrogen bonds were used to ensure the binding stability of the docked complexes in the atomistic simulation. Thus, Klebsiella pneumoniae and its potential compounds can be employed as an alternative to antibiotics for aquaculture, demonstrating their effectiveness in suppressing Aeromonas sp.

Complete genome sequencing of Bacillus cabrialesii TE3T: A plant growth-promoting and biological control agent isolated from wheat (Triticum turgidum subsp. durum) in the Yaqui Valley

Abstract: Bacillus cabrialesii TE3T is a strictly aerobic and Gram-stain-positive plant growth-promoting bacterium, motile and catalase-positive. In addition, strain TE3T was also recently described as a biological control agent. Here, we present the complete circularized genome of this type strain, as well as a whole genome analysis identifying genes of agricultural interest. Thus, a hybrid assembly method was performed using short-read sequencing through the Illumina MiSeq platform, and long-read sequencing through the MinION sequencing technology by Oxford Nanopore Technology (ONT). This assembly method showed a closed circular chromosome of 4,125,766 bp and 44.2% G + C content. The strain TE3T genome annotation, based on the RAST platform, presented 4,282 Coding DNA sequences (CDS) distributed in 335 subsystems, from which 4 CDS are related to the promotion of plant growth and 28 CDS to biological control. Also, Prokka (Rapid Prokaryotic Genome Annotation) predicted a total of 119 RNAs composed of 87 tRNAs, 31 rRNA, and 1 tmRNA; and the PGAP (Prokaryotic Genome Annotation Pipeline) predicted a total of 4,212 genes (3,991 CDS). Additionally, seven putative biosynthetic gene clusters were identified by antiSMASH, such as Fengycin, Bacilysin, Subtilosin A, Bacillibactin, Bacillaene, Surfactin, and Rizocticin A, which are related to antimicrobial and antifungal properties, whose gene presence was further supported by the Prokaryotic Genome Annotation Pipeline (PGAP) annotation. Thus, the complete genome of Bacillus cabrialesii TE3T showed promising bioactivities for the use of this type strain to bioformulate bacterial inoculants for sustainable agriculture.