Biofilm-forming bacteria play a key role in the removal of heavy metals including hexavalent chro... more Biofilm-forming bacteria play a key role in the removal of heavy metals including hexavalent chromium [Cr(VI)] from contaminated sites. In this study, biofilm-forming B. haynesii was examined for extracellular polymeric substances (EPS) production and hexavalent chromium [Cr(VI)] reduction potential. Exposure of B. haynesii with Cr(VI) (12.5-100 mg L-1) for 48 h enhanced pellicle dry weight (20-24%), cell-size (5.1-23.2%) and cell granularity (8.5-19.2%). Also, EPS production was increased by 10-35% by promoting the synthesis of protein (94-119%) and polysaccharide (2-33%) components in EPS. Further, the reduction (27.7 %) and distribution (15.87%) of Cr(VI) were mainly mediated by EPS than the other cellular fractions. Findings of the study suggest that the EPS from B. haynesii was efficiently reduced to Cr(VI) present in aqueous medium and the potential of the organism can be further explored for the mitigation of Cr(VI) contamination.
The effective degradation of lignin from paper mill effluent is an important for environmental sa... more The effective degradation of lignin from paper mill effluent is an important for environmental safety. This research is primarily concerned with the identification of lignin-degrading Bacillus cereus from activated sludge and their possible use for the degradation of Kraft lignin (KL). This strain was involved in the production of lignin peroxidase-LiP (3.20 U/mL), manganese peroxidase-MnP (20.36 U/mL), and laccase (21.35 U/mL) enzymes, which were responsible for high KL degradation (89%) and decolorization (40%) at 1000 mg/L KL in 3 days. The SEM-EDS, UV-Vis, FTIR, and GC-MS analysis were used to analyze the bacterial cell and KL interactions to trace the KL degradation process. The significant reduction of pollutants (KL-72.5%, color-62.0%, COD-45.05%) and reduction in toxicity (80%) of bacterial-treated effluent indicated that B. cereus has the potential to be used in the degradation of pollutants from paper mill effluents.
Microorganisms for Sustainable Environment and Health, 2020
Abstract The ligninolytic enzymes (laccase, manganese peroxidase, lignin peroxidase) have a wide ... more Abstract The ligninolytic enzymes (laccase, manganese peroxidase, lignin peroxidase) have a wide range of applications, including in the industrial and environmental sectors. Lignin peroxidase (LiP; EC 1.11.1.14) is a heme-containing key enzyme of lignin degradation, and it is known as diaryl propane oxygenase. Being an oxidoreductase in chemical nature, LiP is an H2O2-dependent enzyme and catalyzes various phenolic and nonphenolic compounds. The diverse variety of microbes are known for LiP production in the environment. However, fungal-mediated ligninolytic enzymes have been studied extensively with its even greater advantages due to their thermostability, a wide range of pH values, fewer by-products, and high specificity. In the presenting chapter, we explore the ligninolytic enzymes, specially dedicated to lignin peroxidase. The broad and detailed information has dedicated to lignin peroxidases, like; the sources, production, mode of action, and various applications in industrial sectors. The potential use of this enzyme extends through many industries, including; pulp and paper, cosmetics, textile, bioremediation, energy, and cosmetics. Besides, this chapter also provides recent updates on lignin peroxidase production along with their current applications.
Biodegradation of environmentally hazardous synthetic dyes by enzymes has been achieved the highe... more Biodegradation of environmentally hazardous synthetic dyes by enzymes has been achieved the highest interest in recent years. In this work, we optimized Remazol Brilliant Blue R (RBBR) dye biodegradation by Arthrographis kalrae derived laccase via the Box-Behnken design (BBD) approach of the surface response methodology (RSM). Optimization of dye decolourisation by one variable at a time (OVAT) approach resulted in optimal dye decolourisation at laccase dose (2 IU mL-1), pH (7.0), temperature (35 °C), incubation time (240 min), and initial dye concentration (100 mg L-1). The optimized process through BBD enhanced dye decolourisation (97.18%). Fourier Transform Infrared Spectroscopy and UV-Visible Spectrophotometry have proven biodegradation. In addition, in comparison to untreated samples, the laccase-treated dye sample showed relatively less phyto- and cytotoxic effect on Allium cepa L. Extra Precision Glide docking exhibited the binding affinity score of -5.355 kcal mol-1, between laccase-RBBR complex.
Treatment of tannery effluent (TE) using bacterial biofilm is a trending approach in the current ... more Treatment of tannery effluent (TE) using bacterial biofilm is a trending approach in the current scenario, due to greater survival and adaptation in stress conditions. The present study is concerned with the characterization of biofilm-forming bacterium Enterococcus faecium from tannery sludge and the investigation of their activity under different physiological conditions. Biofilm formation by E. faecium was strongly affected by variable physiological conditions. The optimum conditions were pH 7.5, temperature 28 °C, incubation time up to 96 h, glucose 1%, yeast extract 0.1-0.5%, NaCl 0.1-0.5%, tannery effluent-TE up to 50% v/v and Cd, Cr (VI) and Ni from 0.25 to 0.5 mM. Further, E. faecium treated TE was less phytotoxic on the fenugreek plant than the TE treated by non-biofilm forming isolate. The toxicity of TE could be reduced by the potentially biofilm-forming bacteria, which may be used in the bioremediation process.
Microorganisms for Sustainable Environment and Health, 2020
Abstract The release of organic and inorganic pollutants into the environment due to domestic, ag... more Abstract The release of organic and inorganic pollutants into the environment due to domestic, agricultural, and industrial activities poses serious threats to the environment and public health. The existing conventional wastewater treatment plants are insufficient to remove contaminants altogether and therefore more productive and innovative treatment approaches are being explored widely. Among the emerging biological processes, bacterial biofilm-mediated wastewater treatment has shown many advantages compared with other emerging technologies. Biofilm in various bioremediation systems such as biofilters, aerobic, and anaerobic granular sludge reactors, and rotating disk contractors are being explored for treating wastewaters. However, the development of a robust and reliable biofilm-mediated remediation technology with feasibility for implementation at a massive scale remains challenging. Therefore an in-depth understanding of the biofilm formation processes and specific mechanisms are necessary to improve biofilm-mediated bioremediation. In this chapter we discuss the various aspects such as the nature and role of biofilm for various prospective bioremediations. Various topics related to biofilm formation for applications such as the biofilm life cycle, microbes involved, factors affecting the biofilm formation and biofilm properties, associated extracellular polysaccharide, spatial heterogeneity, and microbial interaction have been discussed with updated information. Besides, the emerging scope and miscellaneous use of biofilms with their adverse impacts on the environment have been discussed. Most of the aspects covered are unique with detailed description of the properties and processes which are likely to help in the improvement and further development of the biofilm-mediated bioremediation.
Biodegradation of Azure-B dye by Serratia liquefaciens and its validation by phytotoxicity, genot... more Biodegradation of Azure-B dye by Serratia liquefaciens and its validation by phytotoxicity, genotoxicity and cytotoxicity studies
INTERNATIONAL JOURNAL OF PLANT AND ENVIRONMENT, 2016
In this study, an enterobacterium was isolated from treated tannery wastewater and characterized ... more In this study, an enterobacterium was isolated from treated tannery wastewater and characterized as gram-negative, rod shaped, motile, and lactose fermenting bacterium. Further, based on the 16S rRNA gene sequence analysis, the bacterium was identified as Pantoea sp. with accession number The antibiotic and heavy KJ576899. metal resistant property of isolated bacterium was investigated by the disk diffusion method on Muller-Hinton and nutrient agar medium amended with the increasing concentrations of various toxic metal ions, respectively. Results showed that the isolated bacterium was sensitive for amikacin, ampicillin, cefepime, cetriaxone, chloramphenicol, levofloxacin, meropenem, nalidixic acid, piperacillin and tobramycin, resistant for aztreonam, carbenicillin, cefotaxime, ceftazidime, ciprofloxacin, cotrimoxazole, imepenam, moxifloxacin, streptomycin and tetracycline, but intermediate for amoxicillin and gentamicin. In addition, the bacterium also showed the Minimum Inhibitor...
Biofilm formation ability of bacteria makes them potential in the field of tannery effluent treat... more Biofilm formation ability of bacteria makes them potential in the field of tannery effluent treatment. However, the hazardous nature of effluent and environmental conditions may disturb the biofilm formation ability of bacteria which ultimately affects their effluent treatment efficiency. Accordingly, we isolated and characterized biofilm-forming bacteria Bacillus vallismortis (MT027009), Bacillus haynesii (MT027008), and Alcaligenes aquatilis (MT027005) from tannery sludge and examined them for biofilm formation under variable environmental conditions. Biofilm formation in tryptic soy broth (TSB) at different incubation times (24-120 h) revealed that the biofilm formation activity of the strain B. haynesii was not affected by incubation time, whereas the increase in biofilm formation was observed in the case of B. vallismortis (28 %) and A. aquatilis (52 %) after 48 h. The medium pH (pH 5.0-9.0) had a limited effect on biofilm formation except in the case of A. aquatilis at pH 5.0 (94 %) and pH 9.0 (80 %). Furthermore, compared to the controls (only TSB), the strains B. vallismortis, B. haynesii, and A. aquatilis showed enhanced biofilm formation in undiluted tannery effluent (28, 33, and 21 %) and 25 mg L-1 Cr(VI) (23 %, 48 % 32 %). The biofilm structure was influenced by Cr(VI) as revealed by scanning electron microscopy (SEM) analysis. The results of Cr(VI) bioreduction studies suggest that bacterial biofilm (60-99 %) has a greater potential to remove Cr(VI) than planktonic cells (43-94 %). The results of the study provide important data on biofilm formation by indigenous bacteria in effluent environment conditions, making them potential isolates for tannery effluent treatment.
The tannery industries have greatly improved their treatment system; treated effluents still need... more The tannery industries have greatly improved their treatment system; treated effluents still need to be properly delineated for contaminants and toxicity. In this study, the analysis of both raw and treated tannery effluents (TEs) revealed the maximum reduction of chromium (91%), followed by chemical oxygen demand (COD) (76.7%), total dissolved solids (TDSs) (43.3%), oil and grease (37.2%), and biological oxygen demand (BOD) (33.3%) after common effluent treatment plant (CETP) treatment. Further, the concentration of TDS (13,317 ± 2.7 mg/l), BOD (280 ± 4.47 mg/l), COD (409 ± 2.4 mg/l), sulfate (3773 ± 7.3 mg/l), nitrate (734.86 ± 0.4 mg/l), chloride (8053.59 ± 18.7 mg/l), and chromium (7.153 ± 0.02 mg/l) in treated TE was 6.3-, 9.3-, 1.6-, 3.8-, 73.4-, 13.4-, and 3.6-fold higher than the permissible limit fixed by Central Pollution Control Board. Gas chromatography-mass spectrometry analysis revealed the presence of recalcitrant organic pollutants such as furan, phthalate, and fatty acid in CETP-treated TE. Phytotoxicity investigation of TE on fenugreek (Trigonella foenum-graecum L.) and mung bean (Vigna radiata L.) seeds germination shows that both raw and CETP-treated TEs were inhibitory for seed germination and plant growth. Further, treated TE inhibited seed germination (30%), root length (97.3%), and shoot length (88.7%) in T. foenum-graecum and at 50% concentration, respectively. However, CETP-treated TE was less toxic than the raw TE. Further, fenugreek seeds were more sensitive to TE, as they could not be germinated in both undiluted raw and treated TEs. The finding of the present study reveals that CETP-treated effluents contain a complex mixture of toxic contaminants, indicating that it is not safe to discharge these effluents into the environment.
Microalgae are recognized as cell factories enriched with biochemicals suitable as feedstock for ... more Microalgae are recognized as cell factories enriched with biochemicals suitable as feedstock for bio-energy, food, feed, pharmaceuticals, and nutraceuticals applications. The industrial application of microalgae is challenging due to hurdles associated with mass cultivation and biomass recovery. The scaleup production of microalgal biomass in freshwater is not a sustainable solution due to the projected increase of freshwater demands in the coming years. Microalgae cultivation in wastewater is encouraged in recent years for sustainable bioeconomy from biorefinery processes. Wastewater from the food industry is a less-toxic growth medium for microalgal biomass production. Traditional wastewater treatment and management processes are expensive; hence it is highly relevant to use low-cost wastewater treatment processes with revenue generation through different products. Microalgae are accepted as potential biocatalysts for the bioremediation of wastewater. Microalgae based purification of wastewater technology could be a universal alternative solution for the recovery of resources from wastewater for low-cost biomass feedstock for industry. This review highlights the importance of microalgal biomass production in food processing wastewater, their characteristics, and different microalgal cultivation methods, followed by nutrient absorption mechanisms. Towards the end of the review, different microalgae biomass harvesting processes with biorefinery products, and void gaps that Sabeela Beevi Ummalyma, Ranjna Sirohi have contributed equally and share co-first authors.
The feasibility of in-silico techniques, together with the computational framework, has been appl... more The feasibility of in-silico techniques, together with the computational framework, has been applied to predictive bioremediation aiming to clean-up contaminants, toxicity evaluation, and possibilities for the degradation of complex recalcitrant compounds. Emerging contaminants from different industries have posed a significant hazard to the environment and public health. Given current bioremediation strategies, it is often a failure or inadequate for sustainable mitigation of hazardous pollutants. However, clear-cut vital information about biodegradation is quite incomplete from a conventional remediation techniques perspective. Lacking complete information on bio-transformed compounds leads to seeking alternative methods. Only scarce information about the transformed products and toxicity profile is available in the published literature. To fulfill this literature gap, various computational or in-silico technologies have emerged as alternating techniques, which are being recognized as in-silico approaches for bioremediation. Molecular docking, molecular dynamics simulation, and biodegradation pathways predictions are the vital part of predictive biodegradation, including the Quantitative Structure-Activity Relationship (QSAR), Quantitative structure-biodegradation relationship (QSBR) model system. Furthermore, machine learning (ML), artificial neural network (ANN), genetic algorithm (GA) based programs offer simultaneous biodegradation prediction along with toxicity and environmental fate prediction. Herein, we spotlight the feasibility of in-silico remediation approaches for various persistent, recalcitrant contaminants while traditional bioremediation fails to mitigate such pollutants. Such could be addressed by exploiting described model systems and algorithm-based programs. Furthermore, recent advances in QSAR modeling, algorithm, and dedicated biodegradation prediction system have been summarized with unique attributes.
Two PCP-degrading bacterial strains, Bacillus cereus (ITRC-S6) and Serratia marcescens (ITRC-S7) ... more Two PCP-degrading bacterial strains, Bacillus cereus (ITRC-S6) and Serratia marcescens (ITRC-S7) were used for the treatment of pulp and paper mill effluent at conditions; 1.0% glucose and 0.5% peptone at 30 +/- 1 degrees C at 120 rpm for 168 h of incubation. These two bacterial strains effectively reduced colour (45-52%), lignin (30-42%), BOD (40-70%), COD (50-60%), total phenol (32-40%) and PCP (85-90%) within 168 h of incubation. However, the highest reduction in colour (62%), lignin (54%), BOD (70%), COD (90%), total phenol (90%) and PCP (100%) was recorded by mixed culture treatment. The bacterial mechanism for the degradation of pulp and paper mill effluent may be explained by an increase in the cells biomass using added co-substrates resulting liberation of significant amount of chloride due to bacterial dechlorination of chlorolignins and chlorophenols this showed reduction in colour, lignin and toxicity in the effluent. Further, GC-MS analysis of ethyl acetate-extractable compounds from treated pulp paper mill effluent reinforces the bacterium capability for the degradation of lignin and pentachlorophenol, as many aromatic compounds such as 2-chlorophenol, 2, 4, 6-trichlorophenol and tetrachlorohydroquinone, 6-chlorohydroxyquinol and tetrachlorohydroquinone detected which were not present in the untreated effluent.
The seasonal physico-chemical and microbial quality of Gola river water has been analyzed after c... more The seasonal physico-chemical and microbial quality of Gola river water has been analyzed after confluence of pulp paper mill waste. The study revealed that it has enhanced 20-30 times pollution load of BOD, COD, TDS, TSS, sulphate, chloride, sodium, nitrate, potassium, lignin and phenol after mixing of pulp paper mill waste with river water in all season. Further, it induced the bacterial growth by increasing most probable number value of E.
Distillery industry generates a huge amount of wastewater, which contains a high strength of orga... more 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.
Biofilm-forming bacteria play a key role in the removal of heavy metals including hexavalent chro... more Biofilm-forming bacteria play a key role in the removal of heavy metals including hexavalent chromium [Cr(VI)] from contaminated sites. In this study, biofilm-forming B. haynesii was examined for extracellular polymeric substances (EPS) production and hexavalent chromium [Cr(VI)] reduction potential. Exposure of B. haynesii with Cr(VI) (12.5-100 mg L-1) for 48 h enhanced pellicle dry weight (20-24%), cell-size (5.1-23.2%) and cell granularity (8.5-19.2%). Also, EPS production was increased by 10-35% by promoting the synthesis of protein (94-119%) and polysaccharide (2-33%) components in EPS. Further, the reduction (27.7 %) and distribution (15.87%) of Cr(VI) were mainly mediated by EPS than the other cellular fractions. Findings of the study suggest that the EPS from B. haynesii was efficiently reduced to Cr(VI) present in aqueous medium and the potential of the organism can be further explored for the mitigation of Cr(VI) contamination.
The effective degradation of lignin from paper mill effluent is an important for environmental sa... more The effective degradation of lignin from paper mill effluent is an important for environmental safety. This research is primarily concerned with the identification of lignin-degrading Bacillus cereus from activated sludge and their possible use for the degradation of Kraft lignin (KL). This strain was involved in the production of lignin peroxidase-LiP (3.20 U/mL), manganese peroxidase-MnP (20.36 U/mL), and laccase (21.35 U/mL) enzymes, which were responsible for high KL degradation (89%) and decolorization (40%) at 1000 mg/L KL in 3 days. The SEM-EDS, UV-Vis, FTIR, and GC-MS analysis were used to analyze the bacterial cell and KL interactions to trace the KL degradation process. The significant reduction of pollutants (KL-72.5%, color-62.0%, COD-45.05%) and reduction in toxicity (80%) of bacterial-treated effluent indicated that B. cereus has the potential to be used in the degradation of pollutants from paper mill effluents.
Microorganisms for Sustainable Environment and Health, 2020
Abstract The ligninolytic enzymes (laccase, manganese peroxidase, lignin peroxidase) have a wide ... more Abstract The ligninolytic enzymes (laccase, manganese peroxidase, lignin peroxidase) have a wide range of applications, including in the industrial and environmental sectors. Lignin peroxidase (LiP; EC 1.11.1.14) is a heme-containing key enzyme of lignin degradation, and it is known as diaryl propane oxygenase. Being an oxidoreductase in chemical nature, LiP is an H2O2-dependent enzyme and catalyzes various phenolic and nonphenolic compounds. The diverse variety of microbes are known for LiP production in the environment. However, fungal-mediated ligninolytic enzymes have been studied extensively with its even greater advantages due to their thermostability, a wide range of pH values, fewer by-products, and high specificity. In the presenting chapter, we explore the ligninolytic enzymes, specially dedicated to lignin peroxidase. The broad and detailed information has dedicated to lignin peroxidases, like; the sources, production, mode of action, and various applications in industrial sectors. The potential use of this enzyme extends through many industries, including; pulp and paper, cosmetics, textile, bioremediation, energy, and cosmetics. Besides, this chapter also provides recent updates on lignin peroxidase production along with their current applications.
Biodegradation of environmentally hazardous synthetic dyes by enzymes has been achieved the highe... more Biodegradation of environmentally hazardous synthetic dyes by enzymes has been achieved the highest interest in recent years. In this work, we optimized Remazol Brilliant Blue R (RBBR) dye biodegradation by Arthrographis kalrae derived laccase via the Box-Behnken design (BBD) approach of the surface response methodology (RSM). Optimization of dye decolourisation by one variable at a time (OVAT) approach resulted in optimal dye decolourisation at laccase dose (2 IU mL-1), pH (7.0), temperature (35 °C), incubation time (240 min), and initial dye concentration (100 mg L-1). The optimized process through BBD enhanced dye decolourisation (97.18%). Fourier Transform Infrared Spectroscopy and UV-Visible Spectrophotometry have proven biodegradation. In addition, in comparison to untreated samples, the laccase-treated dye sample showed relatively less phyto- and cytotoxic effect on Allium cepa L. Extra Precision Glide docking exhibited the binding affinity score of -5.355 kcal mol-1, between laccase-RBBR complex.
Treatment of tannery effluent (TE) using bacterial biofilm is a trending approach in the current ... more Treatment of tannery effluent (TE) using bacterial biofilm is a trending approach in the current scenario, due to greater survival and adaptation in stress conditions. The present study is concerned with the characterization of biofilm-forming bacterium Enterococcus faecium from tannery sludge and the investigation of their activity under different physiological conditions. Biofilm formation by E. faecium was strongly affected by variable physiological conditions. The optimum conditions were pH 7.5, temperature 28 °C, incubation time up to 96 h, glucose 1%, yeast extract 0.1-0.5%, NaCl 0.1-0.5%, tannery effluent-TE up to 50% v/v and Cd, Cr (VI) and Ni from 0.25 to 0.5 mM. Further, E. faecium treated TE was less phytotoxic on the fenugreek plant than the TE treated by non-biofilm forming isolate. The toxicity of TE could be reduced by the potentially biofilm-forming bacteria, which may be used in the bioremediation process.
Microorganisms for Sustainable Environment and Health, 2020
Abstract The release of organic and inorganic pollutants into the environment due to domestic, ag... more Abstract The release of organic and inorganic pollutants into the environment due to domestic, agricultural, and industrial activities poses serious threats to the environment and public health. The existing conventional wastewater treatment plants are insufficient to remove contaminants altogether and therefore more productive and innovative treatment approaches are being explored widely. Among the emerging biological processes, bacterial biofilm-mediated wastewater treatment has shown many advantages compared with other emerging technologies. Biofilm in various bioremediation systems such as biofilters, aerobic, and anaerobic granular sludge reactors, and rotating disk contractors are being explored for treating wastewaters. However, the development of a robust and reliable biofilm-mediated remediation technology with feasibility for implementation at a massive scale remains challenging. Therefore an in-depth understanding of the biofilm formation processes and specific mechanisms are necessary to improve biofilm-mediated bioremediation. In this chapter we discuss the various aspects such as the nature and role of biofilm for various prospective bioremediations. Various topics related to biofilm formation for applications such as the biofilm life cycle, microbes involved, factors affecting the biofilm formation and biofilm properties, associated extracellular polysaccharide, spatial heterogeneity, and microbial interaction have been discussed with updated information. Besides, the emerging scope and miscellaneous use of biofilms with their adverse impacts on the environment have been discussed. Most of the aspects covered are unique with detailed description of the properties and processes which are likely to help in the improvement and further development of the biofilm-mediated bioremediation.
Biodegradation of Azure-B dye by Serratia liquefaciens and its validation by phytotoxicity, genot... more Biodegradation of Azure-B dye by Serratia liquefaciens and its validation by phytotoxicity, genotoxicity and cytotoxicity studies
INTERNATIONAL JOURNAL OF PLANT AND ENVIRONMENT, 2016
In this study, an enterobacterium was isolated from treated tannery wastewater and characterized ... more In this study, an enterobacterium was isolated from treated tannery wastewater and characterized as gram-negative, rod shaped, motile, and lactose fermenting bacterium. Further, based on the 16S rRNA gene sequence analysis, the bacterium was identified as Pantoea sp. with accession number The antibiotic and heavy KJ576899. metal resistant property of isolated bacterium was investigated by the disk diffusion method on Muller-Hinton and nutrient agar medium amended with the increasing concentrations of various toxic metal ions, respectively. Results showed that the isolated bacterium was sensitive for amikacin, ampicillin, cefepime, cetriaxone, chloramphenicol, levofloxacin, meropenem, nalidixic acid, piperacillin and tobramycin, resistant for aztreonam, carbenicillin, cefotaxime, ceftazidime, ciprofloxacin, cotrimoxazole, imepenam, moxifloxacin, streptomycin and tetracycline, but intermediate for amoxicillin and gentamicin. In addition, the bacterium also showed the Minimum Inhibitor...
Biofilm formation ability of bacteria makes them potential in the field of tannery effluent treat... more Biofilm formation ability of bacteria makes them potential in the field of tannery effluent treatment. However, the hazardous nature of effluent and environmental conditions may disturb the biofilm formation ability of bacteria which ultimately affects their effluent treatment efficiency. Accordingly, we isolated and characterized biofilm-forming bacteria Bacillus vallismortis (MT027009), Bacillus haynesii (MT027008), and Alcaligenes aquatilis (MT027005) from tannery sludge and examined them for biofilm formation under variable environmental conditions. Biofilm formation in tryptic soy broth (TSB) at different incubation times (24-120 h) revealed that the biofilm formation activity of the strain B. haynesii was not affected by incubation time, whereas the increase in biofilm formation was observed in the case of B. vallismortis (28 %) and A. aquatilis (52 %) after 48 h. The medium pH (pH 5.0-9.0) had a limited effect on biofilm formation except in the case of A. aquatilis at pH 5.0 (94 %) and pH 9.0 (80 %). Furthermore, compared to the controls (only TSB), the strains B. vallismortis, B. haynesii, and A. aquatilis showed enhanced biofilm formation in undiluted tannery effluent (28, 33, and 21 %) and 25 mg L-1 Cr(VI) (23 %, 48 % 32 %). The biofilm structure was influenced by Cr(VI) as revealed by scanning electron microscopy (SEM) analysis. The results of Cr(VI) bioreduction studies suggest that bacterial biofilm (60-99 %) has a greater potential to remove Cr(VI) than planktonic cells (43-94 %). The results of the study provide important data on biofilm formation by indigenous bacteria in effluent environment conditions, making them potential isolates for tannery effluent treatment.
The tannery industries have greatly improved their treatment system; treated effluents still need... more The tannery industries have greatly improved their treatment system; treated effluents still need to be properly delineated for contaminants and toxicity. In this study, the analysis of both raw and treated tannery effluents (TEs) revealed the maximum reduction of chromium (91%), followed by chemical oxygen demand (COD) (76.7%), total dissolved solids (TDSs) (43.3%), oil and grease (37.2%), and biological oxygen demand (BOD) (33.3%) after common effluent treatment plant (CETP) treatment. Further, the concentration of TDS (13,317 ± 2.7 mg/l), BOD (280 ± 4.47 mg/l), COD (409 ± 2.4 mg/l), sulfate (3773 ± 7.3 mg/l), nitrate (734.86 ± 0.4 mg/l), chloride (8053.59 ± 18.7 mg/l), and chromium (7.153 ± 0.02 mg/l) in treated TE was 6.3-, 9.3-, 1.6-, 3.8-, 73.4-, 13.4-, and 3.6-fold higher than the permissible limit fixed by Central Pollution Control Board. Gas chromatography-mass spectrometry analysis revealed the presence of recalcitrant organic pollutants such as furan, phthalate, and fatty acid in CETP-treated TE. Phytotoxicity investigation of TE on fenugreek (Trigonella foenum-graecum L.) and mung bean (Vigna radiata L.) seeds germination shows that both raw and CETP-treated TEs were inhibitory for seed germination and plant growth. Further, treated TE inhibited seed germination (30%), root length (97.3%), and shoot length (88.7%) in T. foenum-graecum and at 50% concentration, respectively. However, CETP-treated TE was less toxic than the raw TE. Further, fenugreek seeds were more sensitive to TE, as they could not be germinated in both undiluted raw and treated TEs. The finding of the present study reveals that CETP-treated effluents contain a complex mixture of toxic contaminants, indicating that it is not safe to discharge these effluents into the environment.
Microalgae are recognized as cell factories enriched with biochemicals suitable as feedstock for ... more Microalgae are recognized as cell factories enriched with biochemicals suitable as feedstock for bio-energy, food, feed, pharmaceuticals, and nutraceuticals applications. The industrial application of microalgae is challenging due to hurdles associated with mass cultivation and biomass recovery. The scaleup production of microalgal biomass in freshwater is not a sustainable solution due to the projected increase of freshwater demands in the coming years. Microalgae cultivation in wastewater is encouraged in recent years for sustainable bioeconomy from biorefinery processes. Wastewater from the food industry is a less-toxic growth medium for microalgal biomass production. Traditional wastewater treatment and management processes are expensive; hence it is highly relevant to use low-cost wastewater treatment processes with revenue generation through different products. Microalgae are accepted as potential biocatalysts for the bioremediation of wastewater. Microalgae based purification of wastewater technology could be a universal alternative solution for the recovery of resources from wastewater for low-cost biomass feedstock for industry. This review highlights the importance of microalgal biomass production in food processing wastewater, their characteristics, and different microalgal cultivation methods, followed by nutrient absorption mechanisms. Towards the end of the review, different microalgae biomass harvesting processes with biorefinery products, and void gaps that Sabeela Beevi Ummalyma, Ranjna Sirohi have contributed equally and share co-first authors.
The feasibility of in-silico techniques, together with the computational framework, has been appl... more The feasibility of in-silico techniques, together with the computational framework, has been applied to predictive bioremediation aiming to clean-up contaminants, toxicity evaluation, and possibilities for the degradation of complex recalcitrant compounds. Emerging contaminants from different industries have posed a significant hazard to the environment and public health. Given current bioremediation strategies, it is often a failure or inadequate for sustainable mitigation of hazardous pollutants. However, clear-cut vital information about biodegradation is quite incomplete from a conventional remediation techniques perspective. Lacking complete information on bio-transformed compounds leads to seeking alternative methods. Only scarce information about the transformed products and toxicity profile is available in the published literature. To fulfill this literature gap, various computational or in-silico technologies have emerged as alternating techniques, which are being recognized as in-silico approaches for bioremediation. Molecular docking, molecular dynamics simulation, and biodegradation pathways predictions are the vital part of predictive biodegradation, including the Quantitative Structure-Activity Relationship (QSAR), Quantitative structure-biodegradation relationship (QSBR) model system. Furthermore, machine learning (ML), artificial neural network (ANN), genetic algorithm (GA) based programs offer simultaneous biodegradation prediction along with toxicity and environmental fate prediction. Herein, we spotlight the feasibility of in-silico remediation approaches for various persistent, recalcitrant contaminants while traditional bioremediation fails to mitigate such pollutants. Such could be addressed by exploiting described model systems and algorithm-based programs. Furthermore, recent advances in QSAR modeling, algorithm, and dedicated biodegradation prediction system have been summarized with unique attributes.
Two PCP-degrading bacterial strains, Bacillus cereus (ITRC-S6) and Serratia marcescens (ITRC-S7) ... more Two PCP-degrading bacterial strains, Bacillus cereus (ITRC-S6) and Serratia marcescens (ITRC-S7) were used for the treatment of pulp and paper mill effluent at conditions; 1.0% glucose and 0.5% peptone at 30 +/- 1 degrees C at 120 rpm for 168 h of incubation. These two bacterial strains effectively reduced colour (45-52%), lignin (30-42%), BOD (40-70%), COD (50-60%), total phenol (32-40%) and PCP (85-90%) within 168 h of incubation. However, the highest reduction in colour (62%), lignin (54%), BOD (70%), COD (90%), total phenol (90%) and PCP (100%) was recorded by mixed culture treatment. The bacterial mechanism for the degradation of pulp and paper mill effluent may be explained by an increase in the cells biomass using added co-substrates resulting liberation of significant amount of chloride due to bacterial dechlorination of chlorolignins and chlorophenols this showed reduction in colour, lignin and toxicity in the effluent. Further, GC-MS analysis of ethyl acetate-extractable compounds from treated pulp paper mill effluent reinforces the bacterium capability for the degradation of lignin and pentachlorophenol, as many aromatic compounds such as 2-chlorophenol, 2, 4, 6-trichlorophenol and tetrachlorohydroquinone, 6-chlorohydroxyquinol and tetrachlorohydroquinone detected which were not present in the untreated effluent.
The seasonal physico-chemical and microbial quality of Gola river water has been analyzed after c... more The seasonal physico-chemical and microbial quality of Gola river water has been analyzed after confluence of pulp paper mill waste. The study revealed that it has enhanced 20-30 times pollution load of BOD, COD, TDS, TSS, sulphate, chloride, sodium, nitrate, potassium, lignin and phenol after mixing of pulp paper mill waste with river water in all season. Further, it induced the bacterial growth by increasing most probable number value of E.
Distillery industry generates a huge amount of wastewater, which contains a high strength of orga... more 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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Papers by Dr. Abhay Raj