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Microbial fuel cells (MFCs) use microorganisms to break down organic matter and generate power, which is an exciting new field of research. MFCs' power generation relies on oxygen reduction (ORR) at the cathode. However, the slow kinetics of the ORR can severely limit the performance of MFCs. Additionally, the growth of biofilm on the cathode hampers the ORR process. In order to ensure the sustainability of MFCs over time, it is crucial to employ bifunctional catalysts that can address these issues. Biogenic titanium dioxide (TiO2) nanoparticles (NPs) were synthesized and applied to a graphite sheet cathode in this study. Cyanobacteria, Phormidium species NCCU-104, was used to bio-fabricate titanium dioxide (TiO2) nanoparticles. NPs were characterized using SEM and TEM analysis to determine their size, shape, surface morphology, and XRD. The particles had an average size of 18.11 nm, were spherical, and were well-dispersed, according to the results of the physicochemical characterization. TiO2 NPs were evaluated in MFC using different concentrations (0.5–2.5 mg/cm2) in the cathode to generate electricity and coulombic efficiency. MFC with a cathode impregnated with 2.0 mg/cm2 TiO2 NP produced maximum power density (15.2 W/m3), which was 38% more than 0.5 mg/cm2 TiO2 NP. The overall study results indicated that biogenic TiO2 nanoparticles (NPs) could be an effective and low-cost catalyst in the oxygen reduction reaction (ORR) and significantly improve biofouling. Due to its efficient and affordable contribution to the ORR, these results imply that biogenic TiO2 NPs might be a feasible alternative for improving the performance of MFCs. [ABSTRACT FROM AUTHOR]

Phaeodactylum tricornutum is a marine diatom rich in omega-3 fatty acids, a nutraceutical-relevant product. Long chain-polyunsaturated fatty acids (LC-PUFAs) are crucial dietary components for human development and growth. With the availability of genome information and genetic engineering tools, the productivities of OMEGAs have improved, but the functional and organizational relationship of such protein-encoding genes associated with LC-PUFAs biosynthesis is still not clear. Henceforth, our study highlights the conservation pattern, functionality and interaction of LC-PUFAs protein-encoding genes via in silico analysis. The transcriptome and quantitative PCR analysis demonstrates downregulation of ACS4, ELO6b, PTD5a, and MYB106 genes associated with LC-PUFAs synthesis and upregulation of ECoAH and ACAT1 genes associated with β-oxidation in nitrogen-depleted conditions in P. tricornutum. Phylogenomics studies of LC-PUFAs protein-encoding genes show a highly conserved evolutionary pattern in various microalgal lineages. Further, for elucidating the interaction of LC-PUFA metabolic genes, subcellular networks were predicted and pathway enrichment analysis was performed, providing new insights on the crosstalk between LC-PUFA protein-encoding genes (ELO6, PTD5, ACS, and ACL1), regulatory elements (LEC2, MYB, WIN) and transporters (ABCD1). In conclusion, such extensive functional enrichment analysis will undoubtedly aid in the development of genetically engineered algal strains with enhanced production of biomolecules i.e., LC-PUFAs. [ABSTRACT FROM AUTHOR]

The present study was aimed at exploring 37 strains of cyanobacteria for the biofabrication of TiO2 NP and evaluation of their antioxidant, antifungal, antibacterial and hemolytic activity. Screening of cyanobacterial strains was done via SEM, followed by optimisation and characterisation of the best strain. Synechocystis NCCU-370 appeared as the best strain for the synthesis of TiO2 NP in terms of size (73.39 nm) and time (24 h) after screening. Following optimisation, nanoparticles were synthesised in 12 h having an average grain size of 16 nm. The aqueous extract preparation required heating of 5 mg/ml of powdered biomass to 60 °C for 10 min. Optimum conditions for the synthesis of TiO2 NP were found to be pH 7, 30 °C and 12-h cell extract exposure to 0.1 mM of salt. Antioxidant activity was evaluated via DPPH, ABTS and FRAP assay. Antifungal potential was explored against Candida albicans (MIC = 125 µg/ml), Candida glabrata (MIC = 500 µg/ml) and Candida tropicalis (MIC = 250 µg/ml), whereas antibacterial potential was gauged for Bacillus cereus (MIC = 31.25 µg/ml), Escherichia coli (MIC = 31.25 µg/ml) and Klebsiella pneumoniae (MIC = 500 µg/ml) strains. Biogenic TiO2 NP demonstrated partial synergistic effect and excellent biocompatibility. [ABSTRACT FROM AUTHOR]

Biofilms are microbial colonies that are encased in an organic polymeric matrix and are resistant to antimicrobial treatments. Biofilms can adhere to both biotic and abiotic surfaces, allowing them to colonize medical equipment such as urinary and intravenous catheters, mechanical heart valves, endotracheal tubes, and prosthetic joints. Candida albicans biofilm is the major etiological cause of the pathogenesis of candidiasis in which its unobstructed growth occurs in the oral cavity; trachea, and catheters that progress to systemic infections in the worst scenarios. There is an urgent need to discover novel biofilm preventive and curative agents. In the present investigation, an effort is made to observe the role of cyanobacteria-derived AgNPs as a new antibiofilm agent with special reference to candidiasis. AgNPs synthesized through the green route using Anabaena variabilis cell extract were characterized by UV–visible spectroscopy. The nanoparticles were spherical in shape with 11–15 nm size and were monodispersed. The minimum inhibitory concentration (MIC) of AgNPs was obtained at 12.5 μg/mL against C. albicans. AgNPs 25 μg/mL showed 79% fungal cell membrane permeability and 22.2% ROS production. AgNPs (25 μg/mL) also facilitated 62.5% of biofilm inhibition and degradation. Therefore, AgNPs could be considered as a promising antifungal agent to control biofilm produced by C. albicans. [ABSTRACT FROM AUTHOR]

Byline: Mahender. Kyadari, Tasneem. Fatma, Rajvardhan. Azad, Thirumurthy. Velpandian Objective: algae isolates obtained from fresh and marine resources could be one of the richest sources of novel bioactive secondary metabolites [...]