A bacterial strain producing extracellular alkaline thermostable laccase has been isolated from sawdust effluents and identified as Micrococcus species. The laccase was partially purified and characterized. The isolate showed maximum laccase production after 120 h, at 30ºC with an optimum pH of 9.0. The specific activity was 127.94 U/mg with a purification fold of 5.54 was obtained with DEAE-cellulose anion exchange chromatography. The molecular weight of purified laccase was 23 kDa. A temperature of 40ºC and pH of 9.0 was found to be optimum for laccase activity. Laccase was stable at 50ºC and at a pH of 9.0 after 1 h incubation. Laccase retained 70-80% of its activity in the presence of 5% DMSO, butanol, acetone and isopropanol. The laccase activity was inhibited by 10 mM SDS (90%), mercuric chloride (80%) and p-CMB (80%). However, only 30% of the enzyme activity was inhibited by sodium azide and EDTA. The characteristics of partially purified laccase with respect to inhibitors and metal ions contribute towards the understanding for the use of bacterial laccases for industrial applications. Keywords: ABTS, alkaline, laccase, Micrococcus, thermo-stable.
Frankincense (Boswellia sacra oleo gum resin) is reported to possess antimicrobial activity against several pathogens in-vitro. The antimicrobial effects of frankincense oil and its interaction with imipenem and gentamicin against methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant P. aeruginosa were determined through in-vitro methods and an in-vivo study using a rat pneumonia model. Frankincense oil was subjected to GC-MS analysis to determine the different volatile components. Antibacterial effects against MRSA and MDR-P. aeruginosa was evaluated and its MIC and MBC were determined. For the rat pneumonia model (in-vivo), oil was administered at a dose of 500 mg/kg and 1000 mg/kg followed by determination of CFU in lung tissue and histological studies. Frankincense oil did not show a very potent inhibitory effect against MRSA or MDR-P. aeruginosa; the oil did not affect the zone of inhibition or FIC when combined with imipenem or gentamicin indicating a lack of interaction between the oil and the antibiotics. Furthermore, there was no interaction between the antibiotics and the frankincense oil in the in-vivo model. The result of the study revealed that frankincense oil has a weak inhibitory effect against MRSA and MDR-P. aeruginosa, and it did not show any interaction with imipenem or gentamicin.
Phytochemicals are effective and are gaining attention in fighting against drug-resistant bacterial strains. In the present study, rutin and quercetin were tested for antibacterial, antibiofilm, and wound healing activities on excision wounds infected with MDR-
Moringa oleifera is known to possess wound healing activity. The present study evaluated the healing properties of methanolic extract of M. oleifera leaves in excision wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) or P. aeruginosa in diabetic rats. An in vitro study was also carried out to determine the gene expression of VEGF and TGF-β1. Preliminary phytochemical and GC-MS analyses were carried out to determine different chemical constituents present in the extract. M. oleifera was applied locally as an ointment at two different concentrations. Wound contraction, period of epithelization, antioxidant enzyme activities and histological changes were determined. For the gene expression study, HaCaT cell lines were used. The formulation of M. oleifera extract improved wound contraction and decreased the period of epithelization, which was associated with an increase in antioxidant enzyme activities, epithelization, capillary density and collagen formation in MRSA-infected diabetic rats. However, this effect was reduced in diabetic animals infected with P. aeruginosa. An increase in the expression of VEGF and TGF-β1 was observed in HaCaT cell lines. M. oleifera extract promotes the healing of infected wounds in MRSA-infected diabetic rats but is less effective in the healing of wounds infected with P. aeruginosa in diabetic rats.
Human G protein-coupled receptor 35 is regulated by agonist-mediated phosphorylation of a set of five phospho-acceptor amino acids within its C-terminal tail. Alteration of both Ser300 and Ser303 to alanine in the GPR35a isoform greatly reduces the ability of receptor agonists to promote interactions with arrestin adapter proteins. Here, we have integrated the use of cell lines genome edited to lack expression of combinations of G protein receptor kinases (GRKs), selective small molecule inhibitors of subsets of these kinases, and antisera able to specifically identify either human GPR35a or mouse GPR35 only when Ser300 and Ser303 (orce; the equivalent residues in mouse GPR35) have become phosphorylated to demonstrate that GRK5 and GRK6 cause agonist-dependent phosphorylation of these residues. Extensions of these studies demonstrated the importance of the GRK5/6-mediated phosphorylation of these amino acids for agonist-induced internalization of the receptor. Homology and predictive modeling of the interaction of human GPR35 with GRKs showed that the N terminus of GRK5 is likely to dock in the same methionine pocket on the intracellular face of GPR35 as the C terminus of the α5 helix of Gα13 and, that while this is also the case for GRK6, GRK2 and GRK3 are unable to do so effectively. These studies provide unique and wide-ranging insights into modes of regulation of GPR35, a receptor that is currently attracting considerable interest as a novel therapeutic target in diseases including ulcerative colitis.
Abstract Nitriles are organic compounds bearing a CN group; they are frequently known to occur naturally in both fauna and flora and are also synthesized chemically. They have wide applicability in the fields of medicine, industry, and environmental monitoring. However, the majority of nitrile compounds are considered to be lethal, mutagenic, and carcinogenic in nature and are known to cause potential health problems such as nausea, bronchial irritation, respiratory distress, convulsions, coma, and skeletal deformities in humans. Nitrile‐converting enzymes, which are extracted from microorganisms, are commonly termed nitrilases and have drawn the attention of researchers all over the world to combat the toxicity of nitrile compounds. The present review focuses on the utility of nitrile‐converting enzymes, sources, classification, structure, properties, and applications, as well as the future perspective on nitrilases.
Wilt is an important disease of brinjal crop causing significant reduction in yield. In present study, the pathogenic fungus was isolated from infected plant parts and identified based on morphological and cultural characters as Fusarium solani f. sp. melongenae. The in vitro efficacy of different plant extracts viz., Azardiachta indica, Artemessia annua, Eucalyptus globulus; Ocimum sanctum and Rheum emodi were tested to control brinjal wilt pathogen. Different concentrations 5, 10, 15 and 20% of plant extracts was used in the study. All the plant extracts showed significant reduction in the growth of pathogen. Among the different extracts 20% of Azardiachta indica was found most effective followed by Rheum emodi, Eucalyptus globulus, Artemessia annua and Ocimum sanctum. Application of plant extract which are easily available for controlling plant diseases are non-pollutive, cost effective non hazardous and do not disturb ecological balance. Investigations are in progress to test the efficacy of these extracts in field applications.
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