Azoreductase and dye detoxification activities of Bacillus velezensis strain AB.

Azo dyes are known to be a very important and widely used class of toxic and carcinogenic compounds. Although lot of research has been carried out for their removal from industrial effluents, very little attention is given to changes in their toxicity and mutagenicity during the treatment processes. Present investigation describes isolation of a Bacillus velezensis culture capable of degrading azo dye Direct Red 28 (DR28). Azoreductase enzyme was isolated from it, and its molecular weight was found to be 60 kDa. The enzyme required NADH as cofactor and was oxygen-insensitive. Toxicity and mutagenicity of the dye during biodegradation was monitored by using a battery of carefully selected in vitro tests. The culture was found to degrade DR28 to benzidine and 4-aminobiphenyl, both of which are potent mutagens. However, on longer incubation, both the compounds were degraded further, resulting in reduction in toxicity and mutagenicity of the dye. Thus, the culture seems to be a suitable candidate for further study for both decolourization and detoxification of azo dyes, resulting in their safe disposal

Biodiversity and dye decolourization ability of an acclimatized textile sludge.

In the present study, sludge sample from biological treatment plant of a textile industry was acclimatized for decolourization of azo dye Direct Black 38 (DB38). A continuous culture experiment showed that the acclimatized sludge could decolourize 76% of 100mg/l DB38. Bacterial community in the sludge was analyzed using culture-independent molecular approach to get the complete picture of its diversity. RFLP analysis of its 16S rRNA gene library divided the clones into 14 distinct groups. Phylogenetic analysis of these groups showed that they belonged to five different bacterial lineages: beta- and gamma-Proteobacteria (3 and 4 respectively), Bacteroidetes (2), Firmicutes (4) and Actinobacteria (1). The largest number of clones was found to cluster in the gamma-Proteobacteria (54%), followed by Firmicutes (19%), beta-Proteobacteria (14%), Bacteroidetes (10%) and Actinobacteria (3%)

Biological decolourization of C.I. Direct Black 38 by E. gallinarum.

In the present study, an Enterococcus gallinarum strain was isolated from effluent treatment plant of a textile industry based on its ability to decolourize C.I. Direct Black 38 (DB38), a benzidine-based azo dye. Effects of dye concentration and medium composition on dye decolourization were studied. The strain was found to decolourize DB38 even under aerobic conditions. Kinetics of DB38 decolourization was also examined, and V(max) and K(s) of decolourization were found to be higher in Luria broth (12.8 mg l(-1)h(-1) and 490.6 mg l(-1)) than in minimal medium (4.09 mg l(-1)h(-1) and 161.84 mg l(-1)). However, decolourization rate/biomass was found to be higher in minimal medium than in Luria broth, indicating greater decolourization efficiency of biomass in the former. The study also revealed biodegradation of DB38 to benzidine and its further deamination to 4-aminobiphenyl (4-ABP) by the culture. Ammonia released during this process was used as nitrogen source for growth of the culture

Kinetics of decolourisation and biotransformation of direct black 38 by C. hominis and P. stutzeri.

In the present study, a consortium of Cardiobacterium hominis and Pseudomonas stutzeri was isolated from an effluent treatment plant of a textile industry, based on its ability to decolourise azo dyes including direct black 38 (DB38), a benzidine-based azo dye. The role of each culture in the decolourisation process was elucidated, and C. hominis was found to decolourise the dye. Although P. stutzeri could not decolourise the dye, it was found to synergistically enhance dye decolourisation activity of C. hominis by scavenging oxygen in the medium and creating an anaerobic condition (oxidation/reduction potential -440 mV), which is known to be necessary for azo dye decolourisation. Together, the cultures could decolourise 90.5% of 100 mg l(-1) DB38 within 24 h. Kinetics of DB38 decolourisation was also examined, and P. stutzeri was found to increase V (max) and K (m) of decolourisation activity of C. hominis by 3.6- and 3-fold, respectively. The study also revealed a pathway of DB38 degradation with the release of benzidine from DB38 and subsequent degradation of benzidine to 4-aminobiphenyl by the cultures

Biomass and lipid enhancement in Chlorella sp. with emphasis on biodiesel quality assessment through detailed {FAME} signature

Abstract In this study, the concentrations of MgSO4, salinity and light intensity were optimised for maximum biomass productivity and lipid content in Chlorella sp. Lipid synthesized at varied experimental conditions was also assessed in detail for biodiesel properties through {FAME} analysis. {FAMEs} mainly composed of C16:0, C16:1(9), C16:3(7, 10, 13), C18:0, C18:1(11), C18:2(9, 12), C18:3(9, 12, 15). The optimum biomass productivity (372.50 mg L−1 d−1) and lipid content (32.57) was obtained at MgSO4-150 ppm; salinity-12.5 ppm, and light intensity-25 μmol m−2 s−1. However, at this condition the cetane number, a major biodiesel property was not complying with worldwide biodiesel standard. Therefore, further optimisations were done to check the suitability of biodiesel fuel. The optimum biomass productivity (348.47 mg L−1 d−1) and lipid content (12.43) with suitable biodiesel fuel properties was obtained at MgSO4-50 ppm, salinity-25 ppm and light intensity-100 μmol m−2 s−1. The validation experiments confirmed the closeness of predicted and measured response values

Prioritizing hazardous pollutants in two Nigerian water supply schemes: a risk-based approach

Objective To rank pollutants in two Nigerian water supply schemes according to their effect on human health using a risk-based approach. Methods Hazardous pollutants in drinking-water in the study area were identified from a literature search and selected pollutants were monitored from April 2010 to December 2011 in catchments, treatment works and consumer taps. The disease burden due to each pollutant was estimated in disability-adjusted life years (DALYs) using data on the pollutant’s concentration, exposure to the pollutant, the severity of its health effects and the consumer population. Findings The pollutants identified were microbial organisms, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead and zinc. All were detected in the catchments but only cadmium, cobalt, chromium, manganese and lead exceeded World Health Organization (WHO) guideline values after water treatment. Post-treatment contamination was observed. The estimated disease burden was greatest for chromium in both schemes, followed in decrea

Cellular alterations and modulation of protein expression in bitumen-challenged human osteoblast cells

Purpose There are many arguments on the carcinogenic potential of bitumen extract. The mechanism of bitumen-induced damage is not well understood at the molecular level. Therefore, in the present study, cell-transforming and tumor-inducing potential of bitumen extract was studied using in vitro [human osteosarcoma (HOS) cells] and in vivo [nude and severe combined immunodeficiency (SCID) mice] models. Methods Gas chromatography/mass spectrometry (GC/MS) analysis was carried out to find out the existence of carcinogenic compounds in the bitumen extract. Cell transformation test, anchorage independence assay, karyotyping assay, tumorigenicity assay, and 2-DE analysis were used to find out the effect of bitumen using the in vitro and in vivo models. Results GC/MS analysis showed the existence of carcinogenic compounds in the bitumen extract. HOS cells were treated with different concentrations (25, 50, and 100 μl/ml) of bitumen extract. Compared to the parental HOS cells, bitumen transformants (HOS T1 and HOS T2) showed the characteristics of anchorage independency, chromosomal anomaly, and cellular transformation. Interestingly, bitumen transformants were not able to form tumor in nude/SCID mice. Proteomic analysis revealed the existence of 19 differentially expressed proteins involved in progression of cancer, angiogenesis, cell adhesion, etc. Conclusions Exposure of bitumen extract to HOS cells results in the cellular transformation similar to cancer cells and can modulate proteins involved in the progression of cancer. We state that the non-tumorogenic potential of bitumen transformant in nude/SCID mice can be attributed to the downregulation of galectin-1, chromodomain helicase DNA-binding protein 1-like gene, and membrane-associated guanylate kinase 2 protein

Associations of polymorphisms in the cytokine genes IL1 beta (rs16944), IL6 (rs1800795), IL12b (rs3212227) and growth factor VEGFA (rs2010963) with anthracosilicosis in coal miners in Russia and related genotoxic effects

Anthracosilicosis (AS), a prevalent form of pneumoconiosis among coal miners, results from the accumulation of carbon and silica in the lungs from inhaled coal dust. This study investigated genotoxic effects and certain cytokine genes polymorphic variants in Russian coal miners with.S. Peripheral leukocytes were sampled from 129 patients with AS confirmed by X-ray and tissue biopsy and from 164 asymptomatic coal miners. Four single-nucleotide polymorphisms were genotyped in the extracted DNA samples: IL1 beta T-511C (rs16944), IL6 C-174G (rs1800795), IL12b A1188C (rs3212227) and VEGFA C634G (rs2010963). Genotoxic effects were assessed by the analysis of chromosome aberrations in cultured peripheral lymphocytes. The mean frequency of chromatid-type aberrations and chromosome-type aberrations, namely, chromatid-type breaks and dicentric chromosomes, was found to be higher in AS patients [3.70 (95% confidence interval {CI}, 3.29-4.10) and 0.28 (95% CI, 0.17-0.38)] compared to the control group [2.41 (95% CI, 2.00-2.82) and 0.09 (95% CI, 0.03-0.15)], respectively. IL1 beta gene T/T genotype (rs16944) was associated with AS [17.83% in AS patients against 4.35% in healthy donors, odds ratio = 4.77 (1.88-12.15), P < 0.01]. A significant increase in the level of certain chromosome interchanges among AS donors is of interest because such effects are typical for radiation damage and caused by acute oxidative stress. IL1 beta T allele probably may be considered as an AS susceptibility factor among coal miners.Russian Foundation for Basic ResearchKemerovo State Univ, Dept Genet, Soviet Ave 73, Kemerovo 650000, RussiaKemerovo State Univ, Dept Bionanotechnol, Blvd Stroiteley 47, Kemerovo 650056, RussiaKemerovo Reg Clin Hosp, Dept Occupat Pathol, Ave October 22, Kemerovo 650066, RussiaReg Clin Ctr Miners Hlth, Dept Occupat Pathol, 7th Microdist 9, Kemerovo Region 652509, RussiaRes Inst Complex Problems Hyg & Occupat Dis, St Kutuzova 23, Novokuznetsk 654041, RussiaRussian Acad Sci, Siberian Branch, Fed Res Ctr Coal & Coal Chem, Soviet Ave 18, Kemerovo 650000, RussiaNatl Environm Engn Res Inst, CSIR, Nagpur 440020, Maharashtra, IndiaLutheran Univ Brazil ULBRA, Postgrad Program Mol & Cellular Biol Appl Hlth, Lab Genet Toxicol, BR-92425900 Canoas, BrazilUniv Fed Sao Paulo, Inst Hlth & Soc, Dept Biosci, Rua Silva Jardim 136, BR-11015020 Sao Paulo, BrazilUniv Fed Sao Paulo, Inst Hlth & Soc, Dept Biosci, Rua Silva Jardim 136, BR-11015020 Sao Paulo, BrazilRFBR: 16-44-420926 r_aRFBR: 16-44-420087 r_aRFBR: 16-34-00441 mol_aWeb of Scienc

Associations of polymorphisms in the cytokine genes IL1β (rs16944), IL6 (rs1800795), IL12b (rs3212227) and growth factor VEGFA (rs2010963) with anthracosilicosis in coal miners in Russia and related genotoxic effects

Anthracosilicosis (AS), a prevalent form of pneumoconiosis among coal miners, results from the accumulation of carbon and silica in the lungs from inhaled coal dust. This study investigated genotoxic effects and certain cytokine genes polymorphic variants in Russian coal miners with АS. Peripheral leukocytes were sampled from 129 patients with AS confirmed by X-ray and tissue biopsy and from 164 asymptomatic coal miners. Four single-nucleotide polymorphisms were genotyped in the extracted DNA samples: IL1β T-511C (rs16944), IL6 C-174G (rs1800795), IL12b A1188C (rs3212227) and VEGFA C634G (rs2010963). Genotoxic effects were assessed by the analysis of chromosome aberrations in cultured peripheral lymphocytes. The mean frequency of chromatid-type aberrations and chromosome-type aberrations, namely, chromatid-type breaks and dicentric chromosomes, was found to be higher in AS patients [3.70 (95% confidence interval {CI}, 3.29–4.10) and 0.28 (95% CI, 0.17–0.38)] compared to the control group [2.41 (95% CI, 2.00–2.82)and 0.09 (95% CI, 0.03–0.15)], respectively. IL1β gene T/T genotype (rs16944) was associated with AS [17.83% in AS patients against 4.35% in healthy donors, odds ratio = 4.77 (1.88–12.15), P < 0.01]. A significant increase in the level of certain chromosome interchanges among AS donors is of interest because such effects are typical for radiation damage and caused by acute oxidative stress. IL1β T allele probably may be considered as an AS susceptibility factor among coal miners