Pulp paper mill effluent has high pollution load due to presence of lignin and its derivatives as major colouring and polluting constituents. In this study, two lignin degrading bacteria IITRL1 and ...IITRSU7 were isolated and identified as Citrobacter freundii (FJ581026) and Citrobacter sp. (FJ581023), respectively. In degradation study by axenic and mixed culture, mixed bacterial culture was found more effective compared to axenic culture as it decolourized 85 and 62% of synthetic and kraft lignin whereas in axenic conditions, bacterium IITRL1 and IITRSU7 decolourized 61 and 64% synthetic and 49 and 54% kraft lignin, respectively. Further, the mixed bacterial culture also showed the removal of 71, 58% TOC; 78, 53% AOX; 70, 58% COD and 74, 58% lignin from synthetic and kraft lignin, respectively. The ligninolytic enzyme was characterized as manganese peroxidase by SDS-PAGE yielding a single band of 43 KDa. The HPLC analysis of degraded samples showed reduction as well as shifting of peaks compared to control indicating the degradation as well as transformation of compounds. Further, in GC-MS analysis of synthetic and kraft lignin degraded samples, hexadecanoic acid was found as recalcitrant compounds while 2,4,6-trichloro-phenol, 2,3,4,5-tetrachloro-phenol and pentachloro-phenol were detected as new metabolites.
Distillery industry generates a huge amount of wastewater, which contains a high strength of organic and inorganic load. Accordingly, this study aims to analyze the physico-chemical pollution ...parameters and the occurrence of phytotoxic, cytotoxic and genotoxic pollutants in wastewater. The result revealed that values of wastewater parameters were recorded as 13268 mg l−1 (BOD), 25144 mg l−1 (COD), 25144 mg l−1 (TS), and 6634 mg l−1 (phosphate), while pH was alkaline. The organic compounds detected by GC-MS were quercetin 7,3′,4′-trimethoxy, octadecadienoic acid, propanoic acid, glycocholic acid methyl ester, cantaxanthin, etc. The Allium cepa was used for the toxicity test with different concentrations of wastewater showed a significant level of reduction in root growth and length after exposure and the maximum reduction was at 25% and 20%. Phytotoxicity studies were performed using Cicer arietinum L. with different concentrations of wastewater, which showed adverse effects on seed germination, root length, and the effect was associated with the increasing concentration of wastewater. A. cepa root tips were used for the analysis of mitotic index (MI), nuclear abnormalities (NA), and chromosomal aberrations (CA). MI was decreasing significantly from 72% (control) to 33%, 22%, 23%, 21%, and 18% at 5%, 10%, 15%, 20%, and 25% wastewater concentration, respectively. The A. cepa root tip cells showed chromosomal aberrations and nuclear abnormalities like vagrant, stickiness, chromosomal loss, c-mitosis, binucleated, micronuclei, and aberrant cell. This study concluded that the wastewater treatment process is insufficient and the discharged waste needs a proper assessment to know the associated health risk.
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•Treated/partially treated DWW contains many toxic organic and inorganic pollutants.•Wastewaters contain high physico-chemical values and inorganic pollutants.•Phytotoxicity of DWW was evaluated by Allium cepa and Cicer arietinum L.•Hazardous organic pollutants were characterized by GC-MS analysis.•Chromosomal and nuclear abnormalities observed in meristematic cell of A. cepa root.
Distillery wastewater has significant amount of coloring compounds and organic substances even after the secondary treatment process, which poses many severe environmental and health threats. ...However, the recalcitrant coloured compounds have not yet been clearly identified. In this study, two bacterial strains DS3 and DS5 capable to decolorize distillery wastewater (DWW) pollutants were isolated and characterized as Staphylococcus saprophyticus (MF182113) and Alcaligenaceae sp. (MF182114), respectively. Results showed that mixed bacterial culture was found more effective decolorizing 71.83% DWW compared to axenic culture DS3 and DS5 resulting only 47.94% and 50.67% decolorization, respectively. The FT-IR and LC-MS/MS analysis of untreated DWW showed the presence of many recalcitrant compounds having different functional groups, but after bacterial treatment, most of compounds get diminished and the toxicity of DWW was reduced significantly. Further, the Nile red staining of Caenorhabditis elegans exposed to untreated and bacteria treated DWW for evaluation of toxicity assay and results revealed that the worms exposed to untreated DWW showed sharp reduction in total fat content having more profound effects, suggesting the diminished nAchR signaling as compare to bacterial treated DWW. Hence, this study revealed that inadequate disposal of untreated DWW may cause transfer of toxic substances into the environment and receiving water bodies.
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•Distillery wastewater has a variety of chemical pollutants.•Bacteria Staphylococcus saprophyticus and Alcaligenaceae sp. were used to treat DWW.•FT-IR and LC-MS used to characterize the DWW pollutants and their metabolites.•Toxicity of DWW pollutants and metabolites was evaluated by Caenorhabditis elegans.•Study showed disposal of untreated DWW may cause severe environmental pollution.
In recent years, lignocellulosic wastes have gathered much attention due to increasing economic, social, environmental apprehensions, global climate change and depleted fossil fuel reserves. The ...unsuitable management of lignocellulosic materials and related organic wastes poses serious environmental burden and causes pollution. On the other hand, lignocellulosic wastes hold significant economic potential and can be employed as promising catalytic supports because of impressing traits such as surface area, porous structure, and occurrence of many chemical moieties (i.e., carboxyl, amino, thiol, hydroxyl, and phosphate groups). In the current literature, scarce information is available on this important and highly valuable aspect of lignocellulosic wastes as smart carriers for immobilization. Thus, to fulfill this literature gap, herein, an effort has been made to signify the value generation aspects of lignocellulosic wastes. Literature assessment spotlighted that all these waste materials display high potential for immobilizing enzyme because of their low cost, bio-renewable, and sustainable nature. Enzyme immobilization has gained recognition as a highly useful technology to improve enzyme properties such as catalytic stability, performance, and repeatability. The application of carrier-supported biocatalysts has been a theme of considerable research, for the past three decades, in the bio-catalysis field. Nonetheless, the type of support matrix plays a key role in the immobilization process due to its influential impact on the physicochemical characteristics of the as-synthesized biocatalytic system. In the past, an array of various organic, inorganic, and composite materials has been used as carriers to formulate efficient and stable biocatalysts. This review is envisioned to provide recent progress and development on the use of different agricultural wastes (such as coconut fiber, sugarcane bagasse, corn and rice wastes, and Brewers' spent grain) as support materials for enzyme immobilization. In summary, the effective utilization of lignocellulosic wastes to develop multi-functional biocatalysts is not only economical but also reduce environmental problems of unsuitable management of organic wastes and drive up the application of biocatalytic technology in the industry.
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•Increasing socio-economic, and environmental apprehensions stresses on valorizing lignocellulosic wastes.•Various lignocellulosic wastes as promising immobilization supports are discussed.•Research gaps – beyond our notice are discussed from the future considerations' viewpoint.
This study deals with the optimization of bacterial degradation of pyridine raffinate by previously isolated two aerobic bacteria ITRCEM1 (Bacillus cereus) and ITRCEM2 (Alcaligens faecalis) with ...accession number DQ4335020 and DQ435021, respectively. The degradation of pyridine raffinate was studied by axenic and mixed bacterial consortium at different nutritional and environmental conditions after the removal of formaldehyde from pyridine raffinate (FPPR). Results revealed that the optimum degradation of pyridine raffinate was observed by mixed bacterial culture in presence of glucose (1% w/v) and peptone (0.2% w/v) at 20% FPPR, pH 7.0, temperature 30°C and 120 rpm at 168 h incubation period . The HPLC analysis of degraded pyridine raffinate samples has indicated the complete removal of α, β and γ picoline. Further, the GC-MS analysis of FPPR pyridine raffinate has shown the presence of pyrazine acetonitrile (6.74), 1,3-dioxepin (8.68), 2-pyridine carboxaldehyde (11.26), propiolactone (12.06), 2-butanol (13.10), benzenesulfonic acid (16.22) and 1,4-dimethyl pyperadine while phenol (17.64) and 3,4-dimethyl benzaldehyde as metabolic products of FPPR.
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•First attempt to utilize kenaf biomass (KB) for cost effective, sustainable PHB production.•Studied various pretreatment methods to utilize KB as feedstock for PHB ...production.•Pretreatment process enhanced saccharification of KB without fermentation inhibitors.•PHB produced exhibited similar structural and thermal properties alike standard PHB.•PHA accumulation, PHB yield using KB hydrolsates was similar to the synthetic sugars mixture.
Kenaf biomass (KB) was employed as feedstock for the synthesis of polyhydroxybutyrate (PHB) using Ralstonia eutropha to replace conventional petroleum-derived polymers. Various pretreatments followed by enzymatic saccharification were applied to release monomeric sugars from KB for PHB production. The effects of increasing concentration of Na2CO3 + Na2SO3 (NaC + NaS) pretreated KB hydrolysates (20–40 g/L) on PHB production were investigated. NaC + NaS pretreated KB hydrolysates (30 g/L) exhibited maximum 70.0% PHA accumulation, with PHB titers of 10.10 g/L and PHB yields of about 0.488 g/g of reducing sugar produced within 36 h of fermentation. PHA accumulation, PHB yield and R. eutropha growth performance using KB hydrolysates were found to be comparable with those of synthetic sugar mixture. Characterization of the produced PHB in terms of crystalline structure, and thermal properties was done using various analytical techniques and results coincide with standard PHB. Thus, green liquor pretreated KB hydrolysates deliver a promising and economically feasible carbon substrate for PHB production.
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•Methylene blue (MB) dye is widely used in cotton, wool and silk industry.•MB dye causes severe effects in water/soil ecologies and public health.•Bacillus albus was able to ...decolorized 99.27 % MB dye and removed 83.87 % COD.•Degradation products of MB dye were analyzed by FT-IR and LC–MS analysis.•Toxicity of untreated and treated MB dye was tested by seed germination test.
In present work, a LiP enzyme producing bacterium was isolated form textile wastewater and sludge sample and identified as Bacillus albus by 16S rRNA gene sequencing analysis. This bacterium decolorized 99.27 % MB dye and removed 83.87 % COD within 6 h at 30 °C, pH 7, 100 rpm and 100 mg/l of dye concentration in presence of glucose and yeast extract as carbon and nitrogen source, respectively. The bacterium also produced LiP enzyme of molecular weight ∼48 kDa, characterized by SDS-PAGE analysis. Different metabolites like monomethylthionine, thionin, (E)-2-(3-Oxopropylidene)-2H-benzob1,4 thiozine-3-carboxylic acid, N-(3,4-dihydroxyphenyl)-N-methylformamide, ethylamine, water and carbon dioxide produced during treatment process were characterized by FT-IR and LC–MS analysis. Further, the toxicity assessment results showed that the toxicity of bacteria treated dye solution was reduced significantly allowing 90 % seed germination indicating that the isolated bacterium B. albus has high potential to decolorize and detoxify MB dye for environmental safety.
An unprecedented rise in population growth and rapid worldwide industrial development are associated with the increasing discharge of a range of toxic and baleful compounds. These toxic pollutants ...including dyes, endocrine-disrupters, heavy metals, personal care products, and pharmaceuticals are destructing nature’s balance and intensifying environmental toxicity at a disquieting rate. Therefore, finding better, novel and more environmentally sound approaches for wastewater remediation are of great importance. Nanoscale materials have opened up some new horizons in various fields of science and technology. Among a range of treatment technologies, nanostructured materials have recently received incredible interest as an emerging platform for wastewater remediation owing to their exceptional surface-area-to-volume ratio, unique electrical and chemical properties, quantum size effects, high scalability, and tunable surface functionalities. An array of nanomaterials including noble metal-based nanostructures, transition metal oxide nanomaterials, carbon-based nanomaterials, carbon nanotubes, and graphene/graphene oxide nanomaterials to their novel nanocomposites and nanoconjugates have been attempted as the promising catalysts to overcome environmental dilemmas. In this review, we summarized recent advances in nanostructured materials that are particularly engineered for the remediation of environmental contaminants. The toxicity of various classes of relevant tailored nanomaterials towards human health and the ecosystem along with perspectives is also presented. In our opinion, an overview of the up-to-date advancements on this emerging topic may provide new ideas and thoughts for engineering low-cost and highly-efficient nanostructured materials for the abatement of recalcitrant pollutants for a sustainable environment.
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•Environmental remediation potentialities of nanostructured materials are reviewed.•Smart mitigation approaches for wastewater remediation are of great importance.•Occurrence and ecotoxicity of pollutants in the environment are described.
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•A novel bacterial consortium GS-TE1310 was used to degrade real tannery effluent.•Consortial treatment showed noticeable reduction in all the pollution parameters.•HP-LC, FT-IR and ...GC–MS analysis confirmed the degradation of organic pollutants.•Consortial treatment also led to substantial amelioration of phytotoxic effects.•Bacterial consortium showed astounding potential for tannery effluent treatment.
The untreated/partially treated effluent discharged from leather tanning industries is heavily polluting our water and soil resources. Hence, the adequate treatment/detoxification of tannery effluent (TE) is required before its safe disposal into the environment. In the present study, an effective degradation of real TE was attained by a newly developed bacterial consortium GS-TE1310 within 120 h with 76.12, 85.32, 71.89, 48.59, 78.81, 69.53, 71.22, and 88.70 % reduction in pollution parameters such as COD, BOD, TDS, phosphate, sulphate, nitrate, Cr, and phenol, respectively. The HP-LC, FT-IR, and GC–MS study showed that most of the organic contaminants identified in the untreated TE were completely mineralized/degraded into new degradation products in the treated TE by the newly developed bacterial consortium GS-TE1310 at 7 pH, 0.5 % glucose and ammonium chloride, 120 rpm, and 20 mL inoculum volume. Further, the bacterially treated TE was used for the phytotoxicity evaluation using Phaseolus aureus L as a terrestrial model organism. Results revealed that the toxicity of bacterially treated TE was significantly reduced, allowing the 70 % germination of seeds, and thus, confirmed the detoxification of leather TE. Overall, the newly developed bacterial consortium GS-TE1310 demonstrated a remarkable potential to efficiently treat/detoxify leather TE for environmental safety.
Currently, scarcity/security of clean water and energy resources are the most serious problems worldwide. Industries use large volume of ground water and a variety of chemicals to manufacture the ...products and discharge large volume of wastewater into environment, which causes severe impacts on environment and public health. Fossil fuels are considered as major energy resources for electricity and transportation sectors, which release large amount of CO2 and micro/macro pollutants, leading to cause the global warming and public health hazards. Therefore, algae-bacterial consortium (A-BC) may be eco-friendly, cost-effective and sustainable alternative way to treat the industrial wastewaters (IWWs) with Bio-H2 production. A-BC has potential to reduce the global warming and eutrophication. It also protects environment and public health as it converts toxic IWWs into non or less toxic (biomass). It also reduces 94%, 90% and 50% input costs of nutrients, freshwater and energy, respectively during IWWs treatment and Bio-H2 production. Most importantly, it produce sustainable alternative (Bio-H2) to replace use of fossil fuels and fill the world's energy demand in eco-friendly manner. Thus, this review paper provides a detailed knowledge on industrial wastewaters, their pollutants and toxic effects on water/soil/plant/humans and animals. It also provides an overview on A-BC, IWWs treatment, Bio-H2 production, fermentation process and its enhancement methods. Further, various molecular and analytical techniques are also discussed to characterize the A-BC structure, interactions, metabolites and Bio-H2 yield. The significance of A-BC, recent update, challenges and future prospects are also discussed.
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•Scarcity and security of clean water and energy resources are the most critical today's problem.•IWWs are rich in color, nutrients, organic pollutants and heavy metals.•IWWs are highly toxic to human/animal/plant/soil/water and microbes.•A-BC is cost-effective and eco-friendly methods of IWWs treatment with Bio-H2 production.•Bio-H2 is a future fuel to fulfil the world's energy demand in eco-friendly manner.
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