Characterization of activated biomass carbon from tea leaf for supercapacitor applications.

In this study, a facile synthesis of chemical and thermal activation of biomass tea-waste materials was explored. A tea-waste biosource carbon was explored by chemical vapor deposition (CVD) method at 700 °C. The KOH-treated carbon (AC-KH) and H3PO4-treated carbon (AC-HP) were systematically studied for morphological characteristics and showed good morphological structures and a few transparent focused layered nanosheets. The elemental analysis done by scanning electron microscopy with energy-dispersive X-ray spectroscopy confirmed the presence of activated carbon. Fourier transform infrared spectroscopy (FT-IR) showed carbon-containing functional groups. The electrochemical analysis showed cyclic voltammetry (CV) curves for electric double layer capacitance (EDLC) with 3 M KOH electrolyte. The Nyquist plot obtained using electrochemical impedance spectroscopy (EIS) showed charge transfer resistance value (Rct) of 6.08 Ω. The electrochemical galvanostatic charge-discharge (GCD) study was conducted to obtain the specific capacitance (Scp) values of AC-KH, which were found to be 131.95 F/g at 0.5 A/g and also AC-HP active material was observed 55.76 F/g at 1 A/g. The AC-KH showed superior electrochemical performance when compared to AC-HP material. Hence, AC-KH is a promising active material for high-energy supercapacitor applications.

Antimicrobial activities of a promising glycolipid biosurfactant from a novel marine Staphylococcus saprophyticus SBPS 15.

Biosurfactants have gained a renewed interest in the recent years for their commercial application in diverse research areas. Recent evidences suggest that the antimicrobial activities exhibited by biosurfactants make them promising molecules for the application in the field of therapeutics. Marine microbes are well known for their unique metabolic and functional properties; however, few reports are available till date regarding their biosurfactant production and antimicrobial potential. In an ongoing survey for bioactive microbial metabolites from microbes isolated from diverse ecological niches, a marine Staphylococcus saprophyticus SBPS 15 isolated from the petroleum hydrocarbon contaminated coastal site, Puducherry, India, was identified as a promising biosurfactant producer based on multiple screening methods. This bacterium exhibited growth-dependent biosurfactant production and the recorded yield was 1.345 ± 0.056 g/L (on dry weight basis). The biosurfactant was purified and chemically characterized as a glycolipid with a molecular mass of 606.7 Da, based on TLC, biochemical estimation methods, FT-IR spectrum and MALDI-TOF-MS analysis. Further, the estimated molecular mass was different from the earlier reports on biosurfactants. This new glycolipid biosurfactant exhibited a board range of pH and temperature stability. Furthermore, it revealed a promising antimicrobial activity against many tested human pathogenic bacterial and fungal clinical isolates. Based on these observations, the isolated biosurfactant from the marine S. saprophyticus revealed board physicochemical stabilities and possess excellent antimicrobial activities which proves its significance for possible use in various therapeutic and biomedical applications. To the best of our knowledge, this is the first report of a biosurfactant from the bacterium, S. saprophyticus.