Strategy for Remediation of Polychlorinated Biphenyls-Contaminated Soil Through Redox Management Based on Electronegativity of the Contaminants.

Literature review reveals that Persistent Organic Pollutants (POPs), such as polychlorinated biphenyls (PCBs), are electron deficient compounds due to the presence of highly electronegative groups. Hence, they are more amenable to anaerobic biodegradation rather than oxidative metabolism. However, the studies on PCBs bioremediation are more inclined towards aerobic treatment. Besides, the past studies are mainly centered on screening and application of PCB-degrading microorganisms. In our opinion the degradative capacity is already present in the native microflora, and choice of electron donor is of paramount importance for faster reductive metabolism of PCBs. In this study, the use of methanol as electron donor with cow dung as the general microbial inoculum resulted in high specific rate of degradation (0.0542-0.0637 /day) for high-chlorinated biphenyls. The % removal of PCBs ranged between 67.7 and 71.7%. It may be the first study on the application of methanol as a cheap electron donor for PCBs biodegradation without bioaugmentation with specifically selected microorganisms.

Simultaneous quantitative monitoring of four indicator contaminants of emerging concern (CEC) in different water sources of Central India using SPE/LC-(ESI)MS-MS.

Environmental occurrence of CECs poses a great threat to both aquatic life and human health. The aim of this study was to optimize and validate SPE/LC-(ESI)MS-MS method for simultaneous quantitative monitoring of two sub-classes of CECs (pharmaceuticals and hormones) and to estimate the concentrations of select CECs in environmental water samples. For all the tested analytes, recoveries in laboratory reagent water were greater than 81%. Average percent (relative standard deviation) RSD of the analytes in recovery, repeatability, and reproducibility experiments were ≤ 10%. Determination coefficients (r2) of primidone, diclofenac, testosterone, and progesterone were estimated to be 0.9979, 0.9972, 0.9968, and 0.9962, respectively. Limits of detection (LOD) for primidone, diclofenac, testosterone, and progesterone were 4.63 ng/L, 5.36 ng/L, 0.55 ng/L, and 0.88 ng/L, respectively. Limits of quantification (LOQ) for primidone, diclofenac, testosterone, and progesterone were 14.72 ng/L, 17.06 ng/L, 1.766 ng/L, and 2.813 ng/L, respectively. Average recoveries in environmental water and wastewater samples were greater than 74% and RSD were ≤ 7%. Trace levels (68.33-125.70 ng/L) of primidone were detected in four environmental water samples, whereas diclofenac was not detected in any of the tested sample. Trace levels of progesterone were observed in two environmental samples (16.64 -203.73 ng/L), whereas testosterone was detected in STP inlet sample (178.16 ng/L).

Transformation Products of Carbamazepine (CBZ) After Ozonation and their Toxicity Evaluation Using Pseudomonas sp. Strain KSH-1 in Aqueous Matrices.

Carbamazepine (CBZ) is an anti-epileptic and anti-convulsant drug widely used for the treatment of epilepsy and other bipolar disorders. Ozone as an advanced oxidation process has been widely used for the degradation of CBZ resulting in the formation of transformation products (ozonides). The present research aims to isolate and identify potential microorganism, capable of degradation of CBZ and its transformation products. The cell viability and cytotoxicity of pure CBZ and their ozone transformation products were evaluated using the cells of Pseudomonas sp. strain KSH-1 through cell viability assay tests. The cells metabolic activity was assessed at varying CBZ concentrations (~ 10-25 ppm, pure CBZ) and cumulatively for ozone transformation products. For pure CBZ, % cell viability decreases as CBZ concentration increases, while, in case of post-ozonated CBZ transformation products, the viability decreases initially and then increases upon exposure of ozone with a maximum cell viability of 97 ± 2.8% evaluated for 2 h post-ozonated samples.

Manganese exposure: Linking down-regulation of miRNA-7 and miRNA-433 with α-synuclein overexpression and risk of idiopathic Parkinson's disease.

Manganese is an essential trace element however elevated environmental and occupational exposure to this element has been correlated with neurotoxicity symptoms clinically identical to idiopathic Parkinson's disease. In the present study we chronically exposed human neuroblastoma SH-SY5Y cells to manganese (100µM) and carried out expression profiling of miRNAs known to modulate neuronal differentiation and neurodegeneration. The miRNA PCR array results reveal alterations in expression levels of miRNAs, which have previously been associated with the regulation of synaptic transmission and apoptosis. The expressions of miR-7 and miR-433 significantly reduced upon manganese exposure. By in silico homology analysis we identified SNCA and FGF-20as targets of miR-7 and miR-433. We demonstrate an inverse correlation in expression levels where reduction in these two miRNAs causes increases in SNCA and FGF-20. Transient transfection of SH-SY5Y cells with miR-7 and miR-433 mimics resulted in down regulation of SNCA and FGF-20 mRNA levels. Our study is the first to uncover the potential link between manganese exposure, altered miRNA expression and parkinsonism: manganese exposure causes overexpression of SNCA and FGF-20 by diminishing miR-7 and miR-433 levels. These miRNAs may be considered critical for protection from manganese induced neurotoxic mechanism and hence as potential therapeutic targets.

Application of cell-based assays for toxicity characterization of complex wastewater matrices: Possible applications in wastewater recycle and reuse.

Exposure to pre-concentrated inlet or outlet STP wastewater extracts at different concentrations (0.001% to 1%) induced dose-dependent toxicity in MCF-7 cells, whereas drinking water extracts did not induce cytotoxicity in cells treated. GC-MS analysis revealed the occurrence of xenobiotic compounds (Benzene, Phthalate, etc.) in inlet/outlet wastewater extracts. Cells exposed to inlet/outlet extract showed elevated levels of reactive oxygen species (ROS: inlet: 186.58%, p<0.05, outlet, 147.8%, p<0.01) and loss of mitochondrial membrane potential (Δψm: inlet, 74.91%, p<0.01; outlet, 86.70%, p<0.05) compared to the control. These concentrations induced DNA damage (Tail length: inlet: 34.4%, p<0.05, outlet, 26.7%, p<0.05) in treated cells compared to the control (Tail length: 7.5%). Cell cycle analysis displayed drastic reduction in the G1 phase in treated cells (inlet, G1:45.0%; outlet, G1:58.3%) compared to the control (G1:67.3%). Treated cells showed 45.18% and 28.0% apoptosis compared to the control (1.2%). Drinking water extracts did not show any significant alterations with respect to ROS, Δψm, DNA damage, cell cycle and apoptosis compared to the control. Genes involved in cell cycle and apoptosis were found to be differentially expressed in cells exposed to inlet/outlet extracts. Herein, we propose cell-based toxicity assays to evaluate the efficacies of wastewater treatment and recycling processes.

Global DNA methylation profiling of manganese-exposed human neuroblastoma SH-SY5Y cells reveals epigenetic alterations in Parkinson's disease-associated genes.

Manganese (Mn) is an essential trace element required for optimal functioning of cellular biochemical pathways in the central nervous system. Elevated exposure to Mn through environmental and occupational exposure can cause neurotoxic effects resulting in manganism, a condition with clinical symptoms identical to idiopathic Parkinson's disease. Epigenetics is now recognized as a biological mechanism involved in the etiology of various diseases. Here, we investigated the role of DNA methylation alterations induced by chronic Mn (100 µM) exposure in human neuroblastoma (SH-SY5Y) cells in relevance to Parkinson's disease. A combined analysis of DNA methylation and gene expression data for Parkinson's disease-associated genes was carried out. Whole-genome bisulfite conversion and sequencing indicate epigenetic perturbation of key genes involved in biological processes associated with neuronal cell health. Integration of DNA methylation data with gene expression reveals epigenetic alterations to PINK1, PARK2 and TH genes that play critical roles in the onset of Parkinsonism. The present study suggests that Mn-induced alteration of DNA methylation of PINK1-PARK2 may influence mitochondrial function and promote Parkinsonism. Our findings provide a basis to further explore and validate the epigenetic basis of Mn-induced neurotoxicity .

Potential Role of Epigenetic Mechanism in Manganese Induced Neurotoxicity.

Manganese is a vital nutrient and is maintained at an optimal level (2.5-5 mg/day) in human body. Chronic exposure to manganese is associated with neurotoxicity and correlated with the development of various neurological disorders such as Parkinson's disease. Oxidative stress mediated apoptotic cell death has been well established mechanism in manganese induced toxicity. Oxidative stress has a potential to alter the epigenetic mechanism of gene regulation. Epigenetic insight of manganese neurotoxicity in context of its correlation with the development of parkinsonism is poorly understood. Parkinson's disease is characterized by the α-synuclein aggregation in the form of Lewy bodies in neuronal cells. Recent findings illustrate that manganese can cause overexpression of α-synuclein. α-Synuclein acts epigenetically via interaction with histone proteins in regulating apoptosis. α-Synuclein also causes global DNA hypomethylation through sequestration of DNA methyltransferase in cytoplasm. An individual genetic difference may also have an influence on epigenetic susceptibility to manganese neurotoxicity and the development of Parkinson's disease. This review presents the current state of findings in relation to role of epigenetic mechanism in manganese induced neurotoxicity, with a special emphasis on the development of Parkinson's disease.

Polymorphisms in DNA repair and multidrug resistance genes among Sindhis of Central India.

Polymorphisms in DNA repair and multidrug resistance genes might contribute to interindividual and interethnic differences in DNA repair capacity and drug disposition respectively. In the present study, we determined the allele and genotype frequencies of four single nucleotide polymorphisms (SNPs) located in the DNA repair genes, XRCC1, XRCC3, XPD, OGG1, namely XRCC1 Arg399Gln, XRCC3 Thr241Met, XPD Lys751Gln, and OGG1 Ser326Cys, respectively and two SNPs located in the multidrug resistance gene, ABCB1, namely ABCB1 C3435T and ABCB1 C1236T, in 33-35 healthy and unrelated Sindhi individuals, residing in the Vidarbha region of Central India and compared them with the Maharashtrian population from the same geographical region and some other HapMap populations from the HapMap database. The study findings reveal that the Indian Sindhis are closely related to the Maharashtrians as well as Utah residents with Northern and Western European ancestry and Gujarati Indians in Houston, Texas in the HapMap database.

Assessment of honking impact on traffic noise in urban traffic environment of Nagpur, India.

BACKGROUND: In context of increasing traffic noise in urban India, the objective of the research study is to assess noise due to heterogeneous traffic conditions and the impact of honking on it. METHOD: Traffic volume, noise levels, honking, road geometry and vehicular speed were measured on national highway, major and minor roads in Nagpur, India. RESULTS: Initial study showed lack of correlation between traffic volume and equivalent noise due to some factors, later identified as honking, road geometry and vehicular speed. Further, frequency analysis of traffic noise showed that honking contributed an additional 2 to 5 dB (A) noise, which is quite significant. Vehicular speed was also found to increase traffic noise. Statistical method of analysis of variance (ANOVA) confirms that frequent honking (p < 0.01) and vehicular speed (p < 0.05) have substantial impact on traffic noise apart from traffic volume and type of road. CONCLUSIONS: The study suggests that honking must also be a component in traffic noise assessment and to identify and monitor "No Honking" zones in urban agglomerations.

Chemotaxis-based endosulfan biotransformation: enrichment and isolation of endosulfan-degrading bacteria.

The study was conducted to isolate endosulfan biotransforming or biodegrading microbes based on chemotaxis. Pseudomonas aeruginosa strain KKc3, Ochrobactrum sp. strain KKc4, Achromobacter xylosoxidans strain KKc6 and Bacillus megaterium KKc7 were isolated based on their migration towards endosulfan in a soil column. Out of the four bacteria, B. megaterium converted endosulfan into toxic metabolite endosulfan sulphate, while the other three bacteria followed the non-toxic endosulfan diol pathway. The mixed culture system consisting of P. aeruginosa, Ochrobactrum sp and A. xylosoxidans could remove 94% of total endosulfan by using endosulfan as the sole source of sulphur.

Mercuric reductase activity of multiple heavy metal-resistant Lysinibacillus sphaericus G1.

A culture was isolated from an industrial mercuric salt-contaminated soil, which could tolerate Cd, Co, Zn, Cr, and Hg up to 190, 525, 350, 935, and 370 µM, respectively. The isolate was identified as Lysinibacillus sphaericus by 16S rRNA gene sequencing. It bioaccumulated Cd, Co, and Zn, and reductively detoxified Cr and Hg. Chromate reductase and mercuric reductase (MerA) activities in the cell extract were 2.4 and 0.13 units mg(-1) protein, respectively. The study also describes designing of broad-specificity primers based on firmicute merA genes. These primers were successfully used to amplify a 440 bp merA fragment from the current isolate. Based on the partial sequence, complete merA ORF of 1641 bp was amplified. It showed 99% similarity to a putative merA gene from distantly related Streptococcus agalactiae, but only 72% identity with the well-characterized merA from a more closely related Bacillus cereus RC607. The gene sequence possessed all the features required for the functioning of MerA enzyme, and its function was confirmed by recombinant expression in E. coli. To the best of our knowledge, this is the first report of full length merA gene from L. sphaericus.

Cytochrome P450 BM3 of Bacillus megaterium - a possible endosulfan biotransforming gene.

Computing chemistry was applied to understand biotransformation mechanism of an organochlorine pesticide, endosulfan. The stereo specific metabolic activity of human CYP-2B6 (cytochrome P450) on endosulfan has been well demonstrated. Sequence and structural similarity search revealed that the bacterium Bacillus megaterium encodes CYP-BM3, which is similar to CYP-2B6. The functional similarity was studied at organism level by batch-scale studies and it was proved that B. megaterium could metabolize endosulfan to endosulfan sulfate, as CYP-2B6 does in human system. The gene expression analyses also confirmed the possible role of CYP-BM3 in endosulfan metabolism. Thus, our results show that the protein structure based in-silico approach can help us to understand and identify microbes for remediation strategy development. To the best of our knowledge this is the first report which has extrapolated the bacterial gene for endosulfan biotransformation through in silico prediction approach for metabolic gene identification.

Carbonic anhydrase mediated carbon dioxide sequestration: promises, challenges and future prospects.

Anthropogenic activities have substantially increased the level of greenhouse gases (GHGs) in the atmosphere and are contributing significantly to the global warming. Carbon dioxide (CO2 ) is one of the major GHGs which plays a key role in the climate change. Various approaches and methodologies are under investigation to address CO2 capture and sequestration worldwide. Carbonic anhydrase (CA) mediated CO2 sequestration is one of the promising options. Therefore, the present review elaborates recent developments in CA, its immobilization and bioreactor methodologies towards CO2 sequestration using the CA enzyme. The promises and challenges associated with the efficient utilization of CA for CO2 sequestration and scale up from flask to lab-scale bioreactor are critically discussed. Finally, the current review also recommends the possible future needs and directions to utilize CA for CO2 sequestration.

Frequency and genotype distribution of ABCB1 gene polymorphisms among Maharashtrian population of Central India.

1. Apart from conferring multidrug resistance to cancer cells, P-glycoprotein (P-gp) encoded by the gene ABCB1 (also, known as Multidrug resistance gene, MDR1), plays a major role in drug disposition. Single nucleotide polymorphisms (SNPs) in the ABCB1 gene might contribute to inter-individual and ethnic differences in drug disposition and thereby, could influence the outcome and prognosis of certain diseases. 2. India is one of the most ethnically and genetically diverse regions of the world. This study was undertaken with a view to determine the allele and genotype frequencies of C3435T and C1236T polymorphisms in the ABCB1 gene among the Maharashtrian population, residing in the Vidarbha region of central India and compare them with HapMap and other Indian populations. The common synonymous C3435T polymorphism has been found to be associated with lower P-gp functional expression and drug uptake, alone or in conjunction with a few other linked SNPs like C1236T. 3. The genotypes of C3435T and C1236T SNPs were determined by PCR-RFLP in 222 healthy and unrelated Maharashtrian individuals. 4. According to the findings of this study, the Maharashtrians were found to be not significantly different from the Gujarati Indians in Houston, Texas in the HapMap database.

Stress-induced lipids are unsuitable as a direct biodiesel feedstock: a case study with Chlorella pyrenoidosa.

The effects of various stresses on the suitability of lipid synthesized by Chlorella pyrenoidosa for biodiesel production were investigated. Lipids were characterized for detailed fatty acid methyl ester profiling and biodiesel properties like cetane number (CN), iodine value, cold filter plugging point (CFPP). Maximum biomass productivity (106.63 mgL(-1)d(-1)) and lipid content (29.68%) were obtained at indoor cultivation (nitrate sufficient, pH 8-10, 24h illumination). However, compared to this condition, other nitrate sufficient cultures [pH 6-8 and 10-12 (24h illumination), and at ambient CO2 and 16:8h light:dark photoperiod (pH unadjusted)] showed ∼12-14% lower lipid productivity. Upon 50% nitrate depletion (at indoor and outdoor; pH unadjusted) lipid content has increased by 7.62% and 17%, respectively. Though stress conditions helped enhancing lipid accumulation, there was two-fold increase in PUFA content compared to that observed at pH 8-10. This resulted in fuel properties which did not comply with the biodiesel standards.

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.

Alkaline peroxide assisted wet air oxidation pretreatment approach to enhance enzymatic convertibility of rice husk.

Pretreatment of rice husk by alkaline peroxide assisted wet air oxidation (APAWAO) approach was investigated with the aim to enhance the enzymatic convertibility of cellulose in pretreated rice husk. Rice husk was presoaked overnight in 1% (w/v) H(2)O(2) solution (pH adjusted to 11.5 using NaOH) (equivalent to 16.67 g H(2)O(2) and 3.63 g NaOH per 100 g dry, untreated rice husk) at room temperature, followed by wet air oxidation (WAO). APAWAO pretreatment resulted in solubilization of 67 wt % of hemicellulose and 88 wt % of lignin initially present in raw rice husk. Some amount of oligomeric glucose (˜8.3 g/L) was also observed in the APAWAO liquid fraction. APAWAO pretreatment resulted in 13-fold increase in the amount of glucose that could be obtained from otherwise untreated rice husk. Up to 86 wt % of cellulose in the pretreated rice husk (solid fraction) could be converted into glucose within 24 hours, yielding over 21 g glucose per 100 g original rice husk. Scanning electron microscopy was performed to visualize changes in biomass structure following the APAWAO pretreatment. Enzymatic cellulose convertibility of the pretreated slurry at high dry matter loadings was also investigated.

Analysis of bacterial community composition of a spring water from the Western Ghats, India using culture dependent and molecular approaches.

Cultivation based and culture independent molecular approaches were used to characterize the composition and structure of bacterial community from a natural warm spring in the Western Ghats, a biodiversity 'hotspot'. Dilution plating was done on three types of media with varying nutrient levels. Relatively nutritionally poor medium supported growth of highest number of bacteria (4.98 × 10(3) ml(-1)) compared to nutritionally rich media. On the basis of different morphological features on the plate, 62 aerobic and heterotrophic bacterial strains were isolated and their 16S rRNA genes were sequenced and analyzed. On the basis of sequence similarity these isolates were found to be distributed in 21 different genera belonging to Proteobacteria (58%) followed by Firmicutes (26%), Actinobacteria (13%) and Bacteroidetes (3%). Amplification of 16S rRNA gene of the community DNA using eubacterial primers, followed by cloning and sequencing revealed that predominant members of the habitat belong to the phylum Cyanobacteria (60%) followed by Proteobacteria (19.5%), Bacteroidetes (6.67%), Actinobacteria (4.4%) and Firmicutes (2.2%) and small ribosomal subunit of a plastid (of Chlorophyta, 2.2%).

DNA repair gene polymorphisms at XRCC1, XRCC3, XPD, and OGG1 loci in Maharashtrian population of central India.

Reduction in DNA repair capacity is associated with increased rates of birth defects, cancer, and accelerated ageing. Genetic polymorphisms in DNA repair genes might influence the repair activities of the enzymes predisposing individuals to cancer risk. Owing to the presence of these genetic variants, inter-individual and ethnic differences in DNA repair capacity have been observed in various populations. India harbors enormous genetic, cultural and linguistic diversity. The present study was undertaken to determine the allele and genotype frequencies of four non-synonymous SNPs, XRCC1 Arg399Gln (C>T, rs25487), XRCC3 Thr241Met (G>A, rs861539), XPD Lys751Gln (T>G, rs13181), and OGG1 Ser326Cys (C>G, rs1052133) in the Maharashtrian population, residing in the Vidarbha region of central India and to compare them with HapMap and other Indian populations. The variant alleles of these polymorphisms have been found to be positively associated with different forms of cancer in several genetic epidemiological studies. The basic prevalence of these polymorphisms in the general population must be known to evaluate their significance in risk assessment in cancer and other phenotypes. About 215 healthy and unrelated individuals from the Maharashtrian population were genotyped for each of these four polymorphisms using PCR-RFLP. The allele and genotype frequency distribution at the four DNA repair gene loci among Maharashtrians revealed a characteristic pattern. To the best of our knowledge, this is the first report of these DNA repair gene polymorphisms in a central Indian population.