Purification and characterization of chitinase from Alcaligenes faecalis AU02 by utilizing marine wastes and its antioxidant activity

Marine waste is an abundant renewable source for the recovery of several value added metabolites with potential industrial applications. This study describes the production of chitinase on marine waste, with the subsequent use of the same marine waste for the extraction of antioxidants. A chitinase-producing bacterium isolated from seafood effluent was identified as Alcaligenes faecalis AU02. Optimal chitinase production was obtained in culture conditions of 37°C for 72 h in 100 ml medium containing 1% shrimp and crab shell powder (1:1) (w/v), 0.1% K2HPO4, and 0.05% MgSO4·7H2O. The molecular weight of chitinase was determined by SDS-PAGE to be 36 kDa. The optimum pH, temperature, pH stability, and thermal stability of chitinase were about 8, 37°C, 5–12, and 40–80°C, respectively. The antioxidant activity of A. faecalis AU02 culture supernatant was determined through scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) as 84%, and the antioxidant compound was characterized by TLC and its FT-IR spectrum. The present study proposed that marine wastes can be utilized to generate a high-value-added product and that pharmacological studies can extend its use to the field of medicine

Effect of orange peel derived activated carbon as a negative additive for lead-acid battery under high rate discharge condition.

In the present study, the effect of orange peel derived activated carbon (OPAC) as an additive to the negative active material in lead acid battery cell was investigated and compared with control cell containing carbon black (CB). The electrochemical performance of negative electrodes is measured by cyclic voltammetry, impedance spectroscopy, galvanostatic charge-discharge. The surface area, crystal structure and morphology are characterized by Brunauer–Emmett–Teller, X-ray diffraction, Raman spectroscopy, transmission electron microscopy and scanning electron microscopy, respectively. OPAC carbon with high surface area (2160 m2/g) and meso/microporous structure exhibits significant influence on the electrochemical kinetics of the negative electrode. The lead acid cells containing OPAC show enhanced discharge performance under high rate discharge conditions, and charge acceptance, when compared to CB containing control cell. The optimum composition for the best electrochemical performance is determined at 0.1 wt% for OPAC. Cell with 0.1 wt.% OPAC show better discharge characteristics (with ~ 20% increase in average discharge capacity) than cell with 0.25 wt.% CB at C2 discharge rate. Oxygen and hydrogen gassing potential delayed by 31 and 37 minutes, respectively, in a cell comprising 0.1 wt.% OPAC, indicating the efficient charging process (PbSO4 to Pb conversion) at C2 rate. Lead acid cell infused with 0.1 wt.% OPAC showed ~ 89% increase in charge acceptance, over control cell containing CB. The inclusion of high specific surface area OPAC linearly increases the redox activity (Pb/PbSO4) especially at high discharge rates, and suppress the sulfation of negative active material

Self-organization, interfacial interaction and photophysical properties of gold nanoparticle complexes derived from resilin-mimetic fluorescent protein rec1-resilin

In this investigation we report the synthesis of optically coupled hybrid architectures based on a new biomimetic fluorescent protein rec1- resilin and nanometer-scale gold nanoparticles (AuNPs) in a one-step method using a non-covalent mode of binding protocol. The presence of uniformly distributed fluorophore sequences, -Ser(Thr)-Tyr-Gly- along the molecular structure of rec1- resilin provides signnificant opportunity to synthesize fluorophore-modified AuNPs bioconjugates with unique photophysical properties. The detailed analyses of the AuNP-bioconjugates, synthesized under different experimental conditions using spectroscopic, microscopic and scattering techniques demonstrate the organizational pathways and the electronic and photophysical properties of the developed AuNP- rec1- resilin bioconjugates. The calculation of the bimolecular quenching constant using the Stern-Volmer equation confirms that the dominant mechanism involved in quenching of fluorescence of rec1- resilin in the presence of AuNP is static. Photoacoustic infrared spectroscopy was employed to understand the nature of the interfacial interaction between the AuNP and rec1- resilin and its evolution with pH. In such bioconjugates the quenched emission of fluorescence by AuNP on the fluorophore moiety of rec1- resilin in the immediate vicinity of the AuNP has significant potential for fluorescence-based detection schemes, sensors and also can be incorporated into nanoparticle-based devices

Zinc Oxide-Containing Porous Boron–Carbon–Nitrogen Sheets from Glycine–Nitrate Combustion: Synthesis, Self-Cleaning, and Sunlight-Driven Photocatalytic Activity

We developed a single-step thermal method that enables successful inclusion of ZnO components in the porous boron–carbon–nitrogen (BCN) framework to form a new class of functional hybrid. ZnO-containing BCN hybrids were prepared by treating a mixture of B₂O₃, glycine, and zinc nitrate at 500 °C. Glycine–nitrate decomposition along with B₂O₃ acts as a source for ZnO-BCN formation. The incorporation of ZnO onto BCN has extended the photoresponse of ZnO in the visible region, which makes ZnO-BCN a preferable photocatalyst relative to ZnO upon sunlight exposure. It is interesting to note that as-prepared 2D ZnO-BCN sheets dispersed in PDMS form a stable coating over aluminum alloys. The surface exhibited a water contact angle (CA) of 157.6° with 66.6 wt % ZnO-BCN in polydimethylsiloxane (PDMS) and a water droplet (7 μL) roll-off angle of <6° and also demonstrates oil fouling resistant superhydrophobicity. In brief, the present study focuses on the gram scale synthesis of a new class of sunlight-driven photocatalyst and also its application toward the development of superhydrophobic and oleophobic coating