ABSTRACT
Trichoderma reesei produces various saccharification enzymes required for biomass degradation. However, the lack of an effective lignin-degrading enzyme system reduces the species' efficiency in producing fermentable sugars and increases the pre-treatment costs for biofuel production. In this study, we heterologously expressed the Ganoderma lucidum RMK1 versatile peroxidase gene (vp1) in the Rut-C30 strain of T. reesei. The expression of purified 6×His-tag-containing recombinant G. lucidum-derived protein (rVP1) was confirmed through western blot, which exhibited a single band with a relative molecular weight of 39 kDa. In saccharification and delignification studies using rice straw, the transformant (tVP7, T. reesei Rut-C30 expressing G. lucidum-derived rVP1) showed significant improvement in the yield of total reducing sugar and delignification, compared with that of the parent T. reesei Rut-C30 strain. Scanning electron microscopy (SEM) of tVP7-treated paddy straw showed extensive degradation of several layers of its surface compared with the parent strain due to the presence of G. lucidum-derived rVP1. Our results suggest that the expression of ligninolytic enzymes in cellulase hyperproducing systems helps to integrate the pre-treatment and saccharification steps that may ultimately reduce the costs of bioethanol production.
ABSTRACT
Chitosan composite material has been used as an efficient drug carrier for potential drug delivery systems in specific cases of wound dressing management. In the present study, 0.5â¯g/L of the antibiotic tetracycline hydrochloride (TCH) was loaded into 1% fungal chitosan (FCS) incorporated with 0.2% of Aloe vera extract (AVE). Two types of sponges were prepared, with and without AVE, such as FCS-AVE-TCH and FCS-TCH, respectively. They were characterized by UV-Visible spectrophotometer, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy (SEM). A constant amount of cumulative TCH release was observed from FCS-AVE-TCH composite sponges at the phosphate buffer saline (pH 7.4), they exhibited good antibacterial activity against both Gram-positive and Gram-negative bacteria. Furthermore, the Vero cells (African green monkey kidney cell line) treated by the composites showed augmented cell viability, which suggests that it could be used as a cost-effective, potential wound dressing material.
ABSTRACT
Silver nanoparticles (AgNPs) have been known for their inhibitory and bactericidal effects. In the present study, less toxic AgNPs using Cunninghamella echinulata is reported for the first time. The obtained AgNPs were characterized using UV-Visible spectrophotometer, XRD, FT-IR, FE-SEM with EDAX and HR-TEM. AgNPs showed the maximum absorbance at 420-430 nm. The transmission electron micrograph revealed the formation of considerably uniform-sized AgNPs with an average size of 20-50 nm. The reducing and capping agents responsible for AgNP synthesis were identified by FT-IR. AgNP-incorporated cotton fabrics exhibited promising antibacterial activity against pathogenic bacteria. In addition, the in vitro cell viability of Vero cells (African green monkey kidney cells) was analyzed and the IC50 value of AgNPs was found to be 62.8 µg/mL. Taken together, these results clearly reveal less toxic AgNPs which could be exploited for various biomedical applications.
ABSTRACT
The wild weed Cyperus rotundus is commonly used as traditional medicine in different parts of the world. Sequential extraction of C. rotundus rhizome with solvents of different polarity namely hexane, chloroform, ethyl acetate, methanol and water were prepared and the free radical scavenging activity was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Based on high antioxidant activity of methanolic extract of C. rotundus rhizome (MRCr) was further investigated for its cytotoxic effect on different human cancer cell lines-breast (MCF-7), cervical (HeLa), liver (Hep G2), prostate (PC-3), colorectal (HT-29) and normal cell line (MCF-12A) by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay evaluated as 50% inhibition of growth (IC50). Apoptosis cells were analysed by flow cytometry stained with annexin V-Fluorescein isothiocyanate conjugate (AF) and propidium iodide (PI). The cellular and nuclear changes were examined under light and fluorescent microscope using 4', 6' diamino-2-phenylindole (DAPI) stain, dual stains of AF/PI and acridine orange/ethidium bromide (AO/EB). The cytotoxic effects on the tested cancer cell lines ranged from 4.52±0.57 to 9.85±0.68µgml-1. The migration assay was showed the inhibitory effect with MRCr. The MRCr showed significant anticancer activity against all the tested cancer cell lines and also protected the non-cancer cells. The anticancer activity suggests further elucidation for the formulation of natural pharmaceutical products in the treatment of cancer.