Isolation and description of keratinase producing marine actinobacteria from South Indian Coastal Region

A unique standard starch casein medium has been implemented for the isolation of actinobacteria from the south Indian marine sediments. A combination of techniques, morphological, physiological and biochemical tests provided the evidence for the isolated actinobacteria. All the 56 isolates were inoculated on milk agar and soya meal agar plates for the primary proteolytic screening and the proportional study was made by ANOVA. Among the 56 isolates, nine showed proteolytic activity in terms of making clear zone around their colony on the plates. Then, nine isolates were subjected to the secondary screening on feather broth where three isolates (IS -1, 2 and 18) showed degradation of feather between seven and ten days. The keratinolytic characters of crude enzymes were scrutinized by feather keratin as substrate and the protein concentration was determined. Then, the isolates were identified at molecular level by 16S rRNA gene amplification technique.Key words: Actinobacteria, keratinase, milk agar, soya meal agar, 16S rRNA gene amplification

Efficient utilization of xylanase and lipase producing thermophilic marine actinomycetes (Streptomyces albus and Streptomyces hygroscopicus) in the production of ecofriendly alternative energy from waste

The marine actinomycetes strain MAC 6 and MAC 14 were used in the production of xylanase and lipase enzyme using wheat bran as an inducer with oats, soy meal and ground nut oil cake. Two strains showed higher xylanase and lipase activity at pH 10.0 and 50°C among 30 actinomycetes screened from sediments of Tiruchendhur coastal areas of Tamil Nadu. The enzymes were produced by solid state fermentation by using 70% of moisture content. More biogas production was observed in oil cake and straw waste with the pretreatment of xylanase and lipase producing strains within short hydraulic retention time.Key words: Biogas, groundnut oilcake, lipase, marine actinomycete, rice straw, solid state fermentation, thermophilic, wheat bran, xylanase

Ecofriendly application of cellulase and xylanase producing marine Streptomyces clavuligerus as enhancer in biogas production from waste

The marine actinomycete strain MAC 9 was used for the production of cellulase and xylanase from wheat bran with inducers oats and soy meal as substrate. Out of 30 actinomycetes screened from sediments of Tiruchendhur coastal areas of Tamil Nadu, India only 8 strains showed both cellulase and xylanase activity. The marine actinomycete exhibited highest enzyme activity at alkaline pH 8-9 with temperature ranging from 40-55°C. The enzymes were used in pretreatment of rice and wheat straw waste for biogas  production. More biogas production was observed in the agricultural waste with the pretreatment of  cellulase, xylanase and the combination of enzymes.Key words: Biogas, cellulase, energy, marine actinomycete, solid state fermentation, thermophilic, wheat bran, xylanase

Indolicidin – Antibacterial activity against bacterial pathogens isolated from ocular infections

Indolicidin is a novel/ promising antimicrobial peptide (a 13 amino acid cationic antimicrobial residue present in the form of cytoplasmic granules of bovine neutrophils) and observed with a broad spectrum of antimicrobial activity against bacteria, fungi, protozoa & even viruses. In the present study, Escherichia coli was transformed with pET 21a+ plasmid carrying indolicidin gene and was expressed. The crude extracts of indolicidin samples induced with varying IPTG concentrations (5mM and 20 mM/ ml of the medium) in Min A medium were checked for antibacterial activities against clinically important ocular bacterial pathogens such as E. coli, Klebsiella sp,, Pseudomonas sp., Acenitobacter sp., Staphylococcus aureus, coagulase negative Staphylococcus aureus, Streptococcus viridans, S. pneumoniae and S. pyogens and its activity was evaluated.&nbsp

Neuropilin 1 Involvement in Choroidal and Retinal Neovascularisation

Purpose Inhibiting VEGF is the gold standard treatment for neovascular age-related macular degeneration (AMD). It is also effective in preventing retinal oedema and neovascularisation (NV) in diabetic retinopathy (DR) and retinal vein occlusions (RVO). Neuropilin 1 (Nrp1) is a co-receptor for VEGF and many other growth factors, and therefore a possible alternative drug target in intra ocular neovascular disease. Here we assessed choroidal and retinal NV in an inducible, endothelial specific knock out model for Nrp1. Methods Crossing Nrp1 floxed mice with Pdgfb-CreERT2 mice produced tamoxifen-inducible, endothelial specific Nrp1 knock out mice (Nrp1ΔEC) and Cre-negative, control littermates. Cre-recombinase activity was confirmed in the Ai3(RCL-EYFP) reporter strain. Animals were subjected to laser-induced CNV (532 nm) and spectral domain-optical coherence tomography (SD-OCT) was performed immediately after laser and at day 7. Fluorescein angiography (FA) evaluated leakage and postmortem lectin staining in flat mounted RPE/choroid complexes was also used to measure CNV. Furthermore, retinal neovascularisation in the oxygen induced retinopathy (OIR) model was assessed by immunohistochemistry in retinal flatmounts. Results In vivo FA, OCT and post-mortem lectin staining showed a statistically significant reduction in leakage (p<0.05), CNV volume (p<0.05) and CNV area (p<0.05) in the Nrp1ΔEC mice compared to their Cre-negative littermates. Also the OIR model showed reduced retinal NV in the mutant animals compared to wild types (p<0.001). Conclusion We have demonstrated reduced choroidal and retinal NV in animals that lack endothelial Nrp1, confirming a role of Nrp1 in those processes. Therefore, Nrp1 may be a promising drug target for neovascular diseases in the eye

Imidacloprid and thiacloprid neonicotinoids bind more favourably to cockroach than to honeybee alpha6 nicotinic acetylcholine receptor: insights from computational studies

The binding interactions of two neonicotinoids, imidacloprid (IMI) and thiacloprid (THI) with the extracellular domains of cockroach and honeybee alpha6 nicotinic acetylcholine receptor (nAChR) subunits in an homomeric receptor have been studied through docking and molecular dynamics (MD) simulations. The binding mode predicted for the two neonicotinoids is validated through the good agreement observed between the theoretical results with the crystal structures of the corresponding complexes with Ac-AChBP, the recognized structural surrogate for insects nAChR extracellular ligand binding domain. The binding site of the two insect alpha6 receptors differs by only one residue of loop D, a serine residue (Ser83) in cockroach being replaced by a lysine residue (Lys108) in honeybee. The docking results show very close interactions for the two neonicotinoids with both alpha6 nAChR models, in correspondence to the trends observed in the experimental neonicotinoid-Ac-AChBP complexes. However, the docking parameters (scores and energies) are not significantly different between the two insect alpha6 nAChRs to draw clear conclusions. The MD results bring distinct trends. The analysis of the average interaction energies in the two insects alpha6 nAChRs shows indeed better affinity of neonicotinoids bound to alpha6 cockroach compared to honeybee nAChR. This preference is explained by tighter contacts with aromatic residues (Trp and Tyr) of the binding pocket. Interestingly, the non-conserved residue Lys108 of loop D of alpha6 honeybee nAChR interacts through van der Waals contacts with neonicotinoids, which appear more favourable than the direct or water mediated hydrogen-bond interaction between the OH group of Ser83 of alpha6 cockroach nAChR and the electronegative terminal group of the two neonicotinoids (nitro in IMI and cyano in THI). Finally, in both insects nAChRs, THI is consistently found to bind more favourably than IMI

Renoprotective effect of tectorigenin glycosides isolated from Iris spuria L. (Zeal) against hyperoxaluria and hyperglycemia in NRK-49Fcells

Oxidative stress has been identified as an underlying factor in the development of insulin resistance, β-cell dysfunction, impaired glucose tolerance and type 2 diabetes mellitus and it also play major role in kidney stone formation. The present study is aimed to elucidate the in vitro nephroprotective activity of two isoflavonoid glycosides, tectorigenin 7-O-β-D-glucosyl-(1→6)-β-D-glucoside (1) and tectorigenin 7-O-β-D-glucosyl-4'-O-β-D-glucoside (2) isolated from the n-BuOH fraction of Iris spuria L. (Zeal) rhizome MeOH extract against oxalate and high glucose-induced oxidative stress in NRK-49F cells. The results revealed that compounds 1 and 2 significantly increased the antioxidant enzyme activities and decreased MDA levels in both oxalate and high glucose stress. Treatment with these phytochemicals effectively down-regulated expression of crystal modulator genes and pro-fibrotic genes in oxalate and high glucose-mediated stress respectively. This study indicates cytoprotective, antioxidant, anti-urolithic and anti-diabetic effects of compounds 1 and 2 against oxalate and high glucose stress