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1.
Environ Monit Assess ; 195(7): 820, 2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37289326

RESUMO

With increasing anthropic activities, a myriad of typical contaminants from industries, hospitals, and municipal discharges have been found which fail to be categorized under regulatory standards and are hence considered contaminants of "emerging concern". Since these pollutants are not removed effectively even by the conventional treatment systems, they tend to inflict potential threats to both human and aquatic life. However, microalgae-mediated remediation strategies have recently gained worldwide importance owing to their role in carbon fixation, low operational cost, and production of high-value products. In this study, centric diatom Chaetoceros neogracilis was exposed to different concentrations of estradiol (E2)-induced synthetic media ranging from 0 to 2 mg L-1, and its impact on the antioxidative system of algae was investigated. The results demonstrate that the nutrient stress caused a strong oxidative response elevating the superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in the 2 mg L-1 E2-treated diatom cultures. However, the specific activity of the H2O2 radical scavenging enzymes like catalase (CAT) was inhibited by the E2 treatment, while that of ascorbate peroxidase (APX) remained comparable to the control (0 mg L-1 of E2). Thus, the study reveals the scope of diatoms as potential indicators of environmental stress even under the varying concentration of a single contaminant (E2).


Assuntos
Antioxidantes , Diatomáceas , Humanos , Antioxidantes/metabolismo , Diatomáceas/metabolismo , Superóxido Dismutase/metabolismo , Peróxido de Hidrogênio , Monitoramento Ambiental , Catalase/metabolismo , Ascorbato Peroxidases/metabolismo , Estresse Oxidativo
2.
Environ Res ; 192: 110277, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33069701

RESUMO

The present study discusses the genomic analysis of Bacillus sp. ISTL8 along with the production of EPS (Extracellular polymeric substances) using carbofuran, a toxic carbamate pesticide. Bacillus strain was isolated from landfill soil and evaluated for high growth rates and EPS production. One strain, renamed ISTL8 grew on a broad range of carbon sources, including toxic carbofuran, while producing copious EPS. Growth assays verified the strain to be thermophilic, low salt tolerant, and with a preference for neutral pH. SEM (Scanning Electron Microscopy) was used for morphological characterization of the EPS while the monomeric composition, bonding patterns and functional groups were deduced by GC-MS (Gas Chromatography-Mass Spectrometry), 1H and 13C NMR (Nuclear Magnetic Resonance) and FTIR (Fourier Transform Infrared Spectroscopy). The production of EPS using carbofuran (carbamate pesticide) as a carbon source was found to be 6.20 ± 0.29 g L-1 containing 61.17% w/w carbohydrates, 29.72% w/w proteins and 6.11% w/w lipids (of dry EPS). The potential cytotoxicity of EPS was evaluated with 3- (4,5-dimethyl thiazol-2-Yl) -2,5-diphenyl tetrazolium bromide (MTT) assay and found non-toxic (2.25%). WGS (Whole genome sequencing) was performed for the strain Bacillus sp. ISTL8 producing EPS; an array of genes putatively involved in the EPS production were identified in several different genomic locations, guiding potential genetic manipulation studies in the future. The results highlight the potency of a bacterial isolate Bacillus sp. ISTL8 to produce non-cytotoxic EPS using carbofuran that can be further harnessed for environmental and commercial applications. Additionally, WGS revealed an array of EPS specific genes which can be effectively engineered for much enhanced production.


Assuntos
Bacillus , Matriz Extracelular de Substâncias Poliméricas , Bacillus/genética , Genômica , Solo , Espectroscopia de Infravermelho com Transformada de Fourier
3.
Environ Res ; 191: 110064, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32846180

RESUMO

In the current study, EPS producing strain Parapedobacter sp. ISTM3 was isolated from Mawsmai cave, Meghalaya, India. The strain ISTM3 showed enhanced EPS production (4.65 ± 0.10 g L-1) at optimized parameters, i.e., pH 8 and 3% molasses as a carbon source. The extracted EPS was structurally characterized by GC-MS, NMR, and FTIR analysis to investigate its monomer compositions, functional groups, and linkage analysis. GC-MS study confirmed the heteropolymeric nature of EPS, whereas the FTIR study confirmed the presence of an aliphatic group, amine group, uronic acid, and saccharides group in the EPS structure. Biosorption of heavy metals by EPS from an aqueous solution was investigated by using heavy metals mixture (Zn2+, Cu2+, Pb2+, Cr6+, Fe2+, and Cd2+) with 20 mg L-1 concentration of each metal. EPS showed the highest removal efficiency and metal adsorption capability for Cr6+ as compared to other heavy metals studied. Also, metal adsorption capability (19.032 mg g-1) and removal efficiency (95.10%) of Cr6+ by EPS were further increased in acidic conditions (pH 5.0). FTIR and SEM-EDX analysis confirmed the biosorption mechanism of EPS. The Freundlich and Langmuir adsorption isotherms were employed to discover the biosorption parameters for Cr6+ uptake with a concentration range of 10-200 mg L-1 by EPS (1 g L-1). The Langmuir model was found to better fit the Cr6+ adsorption by EPS having a maximum adsorption capacity of 33.783 mg g-1. With this, the present study highlights the EPS production potential of Parapedobacter sp. ISTM3, as well as the potential of extracted EPS for heavy metals removals via adsorption.


Assuntos
Matriz Extracelular de Substâncias Poliméricas , Metais Pesados , Adsorção , Matriz Extracelular de Substâncias Poliméricas/química , Concentração de Íons de Hidrogênio , Índia , Cinética , Metais Pesados/análise
4.
Int J Mol Sci ; 21(14)2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32664313

RESUMO

Most of environment-related diseases often result from multiple exposures of abiotic and/or biotic stressors across various life stages. The application of environmental DNA/RNA (eDNA/eRNA) to advance ecological understanding has been very successfully used. However, the eminent extension of eDNA/eRNA-based approaches to estimate human exposure to biotic and/or abiotic environmental stressors to understand the environmental causes of chronic diseases has yet to start. Here, we introduce the potential of eDNA/eRNA for bio-monitoring of human exposome and health effects in the real environmental or occupational settings. This review is the first of its kind to discuss how eDNA/eRNA-based approaches can be applied for assessing the human exposome. eDNA-based exposome assessment is expected to rely on our ability to capture the genome- and epigenome-wide signatures left behind by individuals in the indoor and outdoor physical spaces through shedding, excreting, etc. Records of eDNA/eRNA exposome may reflect the early appearance, persistence, and presence of biotic and/or abiotic-exposure-mediated modifications in these nucleic acid molecules. Functional genome- and epigenome-wide mapping of eDNA offer great promise to help elucidate the human exposome. Assessment of longitudinal exposure to physical, biological, and chemical agents present in the environment through eDNA/eRNA may enable the building of an integrative causal dynamic stochastic model to estimate environmental causes of human health deficits. This model is expected to incorporate key biological pathways and gene networks linking individuals, their geographic locations, and random multi-hits of environmental factors. Development and validation of monitoring of eDNA/eRNA exposome should seriously be considered to introduce into safety and risk assessment and as surrogates of chronic exposure to environmental stressors. Here we highlight that eDNA/eRNA reflecting longitudinal exposure of both biotic and abiotic environmental stressors may serve as records of human exposome and discuss its application as molecular tools for understanding the toxicogenomics basis of environment-related health deficits.


Assuntos
DNA Ambiental/genética , Monitoramento Ambiental/métodos , RNA/genética , Estresse Fisiológico/genética , Animais , Doença Crônica , Meio Ambiente , Expossoma , Humanos , Medição de Risco
5.
J Environ Manage ; 241: 619-630, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30885564

RESUMO

Food and kitchen waste - omnipresent in every corner of the world serve as an excellent source of value added products owing to high organic content. Regardless of existence of various traditional methods of land filling or biogas production used to harness food waste energy, effective conversion of food to valuable resources is often challenged by its heterogenous nature and high moisture content. The current paper tries to lay down the prospects and consequences associated with food waste management. The various social, economical and environmental concerns associated with food waste management especially in terms of green house gas emission and extended rate of leachate generation also has been discussed. The difficulties in proper collection, storage and bioconversion of food waste to valuable by-products are pointed as a big hurdle in proper waste management. Finally, the wide array of value added products developed from food waste after pretreatment are also enlisted to emphasis the prospects of food waste management.


Assuntos
Eliminação de Resíduos , Gerenciamento de Resíduos , Biocombustíveis , Alimentos , Resíduos
6.
Ecotoxicol Environ Saf ; 143: 120-128, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28525815

RESUMO

In the present study, landfill soil of three municipal solid waste landfill sites of Delhi, India were toxico-chemically analyzed for human risk assessment as inadequate information is available on the possible health effects of the contaminants present in landfill soil. The landfill soil samples were prepared for analyzing heavy metal concentration, organic contaminants and toxicity analysis separately. Composite soil sample collected from three landfill sites were analyzed for heavy metal by ICP-AES. Metal concentration so obtained was below the permissible limit of soil but higher than the set limits for effluent. Some of the persistent organic contaminants like phthalates, benzene derivatives, halogenated aliphatic compounds and PAHs derivatives were detected by scan mode GC-MS. Further, concentration of 17 polycyclic aromatic hydrocarbons (PAHs) in landfill soil of Delhi was evaluated by selective ion monitoring GC-MS in order to ascertain their contamination levels and potential health risk. The concentration of total PAHs in the samples ranged from 192 to 348µg/kg. The maximum concentrations of PAHs were found in Ghazipur landfill site followed by Okhla and Bhalswa landfills. Cancer risk (CR) values of sampling sites were within the acceptable range for adults, adolescents and children (both male and female) suggesting that PAHs present in landfill soil are unlikely to pose any cancer risk for population based on dermal contact, ingestion and inhalation exposure pathways. However, landfill soil organic extract showed significant cytotoxic and genotoxic effects on HepG2 cell line as revealed by MTT and Comet assays respectively. The observed MTT EC50 values ranged from 7.58 to 12.9g SedEq/Lalong with statistically significant DNA damage. Thus, although the soil organic extract contained low concentrations of PAHs with negligible carcinogenic potential, but the mixture of organic pollutants present in soil were found to be toxic enough to affect human health due to their synergistic or additive actions.


Assuntos
Derivados de Benzeno/análise , Metais Pesados/análise , Ácidos Ftálicos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/análise , Adolescente , Adulto , Derivados de Benzeno/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Criança , Ensaio Cometa , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Células Hep G2 , Humanos , Índia , Masculino , Metais Pesados/toxicidade , Ácidos Ftálicos/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Medição de Risco , Solo , Poluentes do Solo/toxicidade , Resíduos Sólidos , Instalações de Eliminação de Resíduos
7.
Ecotoxicol Environ Saf ; 141: 259-270, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28359992

RESUMO

Landfilling is the most common solid waste management practice. However, there exist a potential environmental risk to the surface and ground waters due to the possible leaching of contaminants from the landfill leachates. Current municipal solid waste landfill regulatory approaches consider physicochemical characterization of the leachate and do not assess their potential toxicity. However, assessment of toxic effects of the leachates using rapid, sensitive and cost-effective biological assays is more useful in assessing the risks as they measure the overall toxicity of the chemicals in the leachate. Nevertheless, more research is needed to develop an appropriate matrix of bioassays based on their sensitivity to various toxicants in order to evaluate leachate toxicity. There is a need for a multispecies approach using organisms representing different trophic levels so as to understand the potential impacts of leachate on different trophic organisms. The article reviews different bioassays available for assessing the hazard posed by landfill leachates. From the review it appears that there is a need for a multispecies approach to evaluate leachate toxicity.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Eliminação de Resíduos/métodos , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/toxicidade , Aliivibrio fischeri/efeitos dos fármacos , Animais , Bioensaio , Clorófitas/efeitos dos fármacos , Peixes/crescimento & desenvolvimento , Invertebrados/efeitos dos fármacos , Medição de Risco
8.
Ecotoxicol Environ Saf ; 128: 44-51, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26890189

RESUMO

The present study aims to evaluate the feasibility of leachate treatment using a synergistic approach by microalgae and bacteria. Leachate from one of the landfill of Northern India showed the presence of various toxic organic contaminants like naphthalene, benzene, phenol and their derivatives, napthols, pesticides, epoxides, phthalates and halogenated organic compounds. ICP-AES analysis revealed high concentrations of Zn, Cr, Fe, Ni, and Pb beyond the maximum permissible limit of discharge. Bacto-algal co-culture was found to be the most efficient in removal of toxic organic contaminants and heavy metals. Further, detoxification efficiency of bacto-algal treatment was evaluated by Methyl tetrazolium (MTT) assay for cytotoxicity and alkaline comet assay for genotoxicity using hepatoma HepG2 cells. Reduction in toxicity was confirmed by an increase in LC50 by 1.9 fold and reduction in Olive Tail Moment by 40.6 fold after 10 days of treatment. Results of the study indicate bioremediation and detoxification potency of bacto-algal co-culture for leachate treatment.


Assuntos
Bactérias/metabolismo , Metais Pesados/metabolismo , Microalgas/metabolismo , Compostos Orgânicos/metabolismo , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Ensaio Cometa , Células Hep G2 , Humanos , Índia , Metais Pesados/análise , Metais Pesados/toxicidade , Compostos Orgânicos/análise , Compostos Orgânicos/toxicidade , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
9.
Biochim Biophys Acta ; 1830(11): 5193-203, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23876294

RESUMO

BACKGROUND: Three de novo designed low molecular weight cationic peptides (IJ2, IJ3 and IJ4) containing an unnatural amino acid α,ß-didehydrophenylalanine (∆Phe) exhibited potent antifungal activity against fluconazole (FLC) sensitive and resistant clinical isolates of Candida albicans as well as non-albicans and other yeast and filamentous pathogenic fungi. In the present study, their synthesis, susceptibility of different fungi and the mechanism of anti-candidal action have been elucidated. METHODS: The antimicrobial peptides (AMPs) were synthesized by solid-phase method and checked for antifungal activity against different yeasts and fungi by broth microdilution method. Anti-candidal mode of action of the peptides was investigated through detecting membrane permeabilization by confocal microscopy, Reactive Oxygen Species (ROS) generation by fluorometry, apoptosis and necrosis by flow cytometry and cell wall damage using Scanning and Transmission Electron Microscopy. RESULTS AND CONCLUSIONS: The MIC of the peptides against C. albicans and other yeast and filamentous fungal pathogens ranged between 3.91 and 250µM. All three peptides exhibited effect on multiple targets in C. albicans including disruption of cell wall structures, compromised cell membrane permeability leading to their enhanced entry into the cells, accumulation of ROS and induction of apoptosis. The peptides also showed synergistic effect when used in combination with fluconazole (FLC) and caspofungin (CAS) against C. albicans. GENERAL SIGNIFICANCE: The study suggests that the AMPs alone or in combination with conventional antifungals hold promise for the control of fungal pathogens, and need to be further explored for treatment of fungal infections.


Assuntos
Antifúngicos/síntese química , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Peptídeos/síntese química , Peptídeos/farmacologia , Apoptose/efeitos dos fármacos , Caspofungina , Permeabilidade da Membrana Celular/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Sinergismo Farmacológico , Equinocandinas/farmacologia , Fluconazol/farmacologia , Hemólise/efeitos dos fármacos , Lipopeptídeos , Necrose/tratamento farmacológico , Necrose/metabolismo , Espécies Reativas de Oxigênio/metabolismo
10.
Artigo em Inglês | MEDLINE | ID: mdl-24525376

RESUMO

The present study compares in vitro toxicity of electroplating effluent after the batch treatment process with that obtained after the sequential treatment process. Activated charcoal prepared from sugarcane bagasse through chemical carbonization, and tolerant indigenous bacteria, Bacillus sp. strain IST105, were used individually and sequentially for the treatment of electroplating effluent. The sequential treatment involving activated charcoal followed by bacterial treatment removed 99% of Cr(VI) compared with the batch processes, which removed 40% (charcoal) and 75% (bacteria), respectively. Post-treatment in vitro cyto/genotoxicity was evaluated by the MTT test and the comet assay in human HuH-7 hepatocarcinoma cells. The sequentially treated sample showed an increase in LC50 value with a 6-fold decrease in comet-assay DNA migration compared with that of untreated samples. A significant decrease in DNA migration and an increase in LC50 value of treated effluent proved the higher effectiveness of the sequential treatment process over the individual batch processes.


Assuntos
Dano ao DNA , Galvanoplastia , Poluentes Ambientais/toxicidade , Resíduos Industriais/efeitos adversos , Metais Pesados/toxicidade , Mutagênicos/toxicidade , Purificação da Água/métodos , Biodegradação Ambiental , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Carvão Vegetal/química , Ensaio Cometa , Poluentes Ambientais/química , Humanos , Resíduos Industriais/análise , Metais Pesados/química , Mutagênicos/química
11.
Indian J Exp Biol ; 52(11): 1052-61, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25434100

RESUMO

Wide spread use of Di-(2-ethylhexyl) phthalate (DEHP) has made it a ubiquitous contaminant in today's environment, responsible for possible carcinogenic and endocrine disrupting effects. In the present investigation an integrative toxicoproteomic approach was made to study the estrogenic potential of DEHP. In vitro experiments carried out with DEHP (0.1-100 microM) induced proliferations (E-screen assay) in human estrogen receptors-alpha (ERalpha) positive MCF-7 and ERalpha negative MDA-MB-231 breast cancer cells irrespective of their ERa status. Further, DEHP suppressed tamoxifen (a potent anti-breast cancer drug) induced apoptosis in both cell types as shown by flowcytometric cell cycle analysis. Label-free quantitative proteomics analysis of the cell secretome of both the cell lines indicated a wide array of stress related, structural and receptor binding proteins that were affected due to DEHP exposure. The secretome of DEHP treated MCF-7 cells revealed the down regulation of lactotransferrin, an ERalpha responsive iron transport protein. The results indicated that toxicological effects of DEHP did not follow an ERa signaling pathway. However, the differential effects in MCF-7 and MDA-MB-231 cell lines indicate that ERa might have an indirect modulating effect on DEHP induced toxicity.


Assuntos
Neoplasias da Mama/patologia , Dietilexilftalato/toxicidade , Poluentes Ambientais/toxicidade , Receptor alfa de Estrogênio/fisiologia , Estrogênios , Proteínas de Neoplasias/fisiologia , Neoplasias Hormônio-Dependentes/patologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/metabolismo , Receptor alfa de Estrogênio/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Lactoferrina/biossíntese , Lactoferrina/genética , Lactoferrina/metabolismo , Células MCF-7/efeitos dos fármacos , Células MCF-7/metabolismo , Espectrometria de Massas/instrumentação , Microquímica/instrumentação , Proteínas de Neoplasias/efeitos dos fármacos , Proteínas de Neoplasias/metabolismo , Proteômica , Tamoxifeno/antagonistas & inibidores , Tamoxifeno/farmacologia
12.
Prep Biochem Biotechnol ; 43(8): 735-49, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23876135

RESUMO

Cryptococcus albidus shows delignification activity in nature. It was used for the biopulping of eucalyptus wood (Eucalyptus grandis) to access its potential for industrial application in the pulp and paper industry. Enzyme analysis on days 15, 30, and 60 showed the presence of laccase and xylanase as key enzymes. The production of endo-glucanase (CMCase) and exo-glucanase (FPase) was very low. Scanning electron microscopy (SEM) showed the surface colonization of wood and loosening of wood fibers in C. albidus-treated samples. Fourier-transformation infrared spectroscopy (FT-IR) indicated the chemical modification of eucalyptus wood. Denaturing gradient gel electrophoresis (DGGE) analysis on days 15, 30, and 60 confirmed the presence of C. albidus throughout the experiments. Cryptococcu albidus was able to suppress the growth of a native population. Further, after 60 days both the control and treated eucalyptus wood chips were given kraft pulping treatment. The kappa number of pulp of control wood was 21 and for treated wood was 17. Kappa number is considered a measure of lignin content in wood; hence the treatment of eucalyptus by C. albidus (biopulping) was effective in reducing its lignin content and can be used for biopulping in the pulp and paper industry.


Assuntos
Cryptococcus/química , Endo-1,4-beta-Xilanases/química , Eucalyptus/química , Proteínas Fúngicas/química , Lacase/química , Lignina/metabolismo , Madeira/metabolismo , Cryptococcus/enzimologia , Hidrólise , Microscopia Eletrônica de Varredura , Papel , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Prep Biochem Biotechnol ; 42(2): 113-24, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22394061

RESUMO

This study deals with the characterization of laccase enzyme activity produced by Cryptococcus albidus. Industrial wastes like effluent and sludge are complex mixtures of a number of chemicals. These chemicals can interfere with the proper functioning of the enzymes used for bioremediation. Thus, it is important to study the effect of such interfering solvents, detergents, metal chelators, and other chemicals on enzyme activity before industrial applications. Laccase showed maximum activity at pH 2.5 and temperature 20-30°C when ABTS was used as a substrate. The enzyme followed Michaelis-Menten kinetics: K(m) was 0.8158 mM and V(max) was 1527.74 U/mg. Laccase showed good thermostability with a half-life of 81 min at 25°C, 77 min at 35°C, 64 min at 45°C, 36 min at 55°C, and 21 min at 65°C. There was no effect of sodium dodceyl sulfate (SDS) (0.1-1.0%) and EDTA (0.1-0.5%) on laccase activity. Sodium azide and 2-mercaptoethanol showed complete inhibition of laccase activity at 0.1% concentration. At lower concentrations of acetone and acetonitrile, laccase was able to maintain its activity. However, the activity was completely inhibited at a concentration of 50% or above of acetone, methanol, 1,4-dioxan, and acetonitrile.


Assuntos
Cryptococcus/enzimologia , Microbiologia Industrial , Lacase/metabolismo , Benzotiazóis/metabolismo , Biodegradação Ambiental , Detergentes/metabolismo , Ácido Edético/metabolismo , Concentração de Íons de Hidrogênio , Lacase/antagonistas & inibidores , Mercaptoetanol/metabolismo , Azida Sódica/metabolismo , Dodecilsulfato de Sódio/metabolismo , Solventes/metabolismo , Ácidos Sulfônicos/metabolismo , Temperatura
14.
Environ Technol ; 33(1-3): 113-22, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22519094

RESUMO

A bacterium isolated from soil and sediment ofa leather tanning mill's effluent was identified as Serratia sp. by the analysis of 16S rDNA. Scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) and transmission electron microscopy (TEM) were used to assess morphological changes and confirm chromium biosorption in Serratia sp. both in a shake-flask culture containing chromium and in a tannery wastewater. The SEMEDX and the elemental analysis of the chromate-containing samples confirmed the binding of chromium with the bacterial biomass. The TEM exhibited chromium accumulation throughout the bacterial cell, with some granular deposits in the cell periphery and in the cytoplasm. X-ray diffraction analysis (XRD) was used to quantify the chromium and to determine the chemical nature of the metal-microbe interaction. The XRD data showed the crystalline character of the precipitates, which consisted of mainly calcium chromium oxide, chromium fluoride phosphate and related organo-Cr(III) complex crystals. The XRD data also revealed a strong involvement of cellular carboxyl and phosphate groups in chromium binding by the bacterial biomass. The results of the study indicated that a combined mechanism of ion-exchange, complexation, croprecipitation and immobilization was involved in the biosorption of chromium by bacterial cells in contaminated environments.


Assuntos
Cromo/metabolismo , Serratia/metabolismo , Biodegradação Ambiental , Biotransformação , Resíduos Industriais/análise , Filogenia , Serratia/genética , Serratia/isolamento & purificação , Curtume
15.
Environ Sci Pollut Res Int ; 29(26): 38950-38971, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35304714

RESUMO

The increase in demand of fossil fuel uses for developmental activity and manufacturing of goods have resulted a huge emission of global warming gases (GWGs) in the atmosphere. Among all GWGs, CO2 is the major contributor that inevitably causes global warming and climate change. Mitigation strategies like biological CO2 capture through sequestration and their storage into biological organic form are used to minimize the concentration of atmospheric CO2 with the goal to control climate change. Since increasing atmospheric CO2 level supports microbial growth and productivity thus microbial-based CO2 sequestration has remarkable advantages as compared to plant-based sequestration. This review focuses on CO2 sequestration mechanism in bacteria through different carbon fixation pathways, involved enzymes, their role in calcite, and other environmentally friendly biomaterials such as biofuel, bioplastic, and biosurfactant.


Assuntos
Dióxido de Carbono , Combustíveis Fósseis , Bactérias/metabolismo , Carbono/metabolismo , Dióxido de Carbono/análise , Sequestro de Carbono , Estudos Prospectivos
16.
Chemosphere ; 287(Pt 3): 132321, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34563778

RESUMO

Agroforestry, an integration of farming system with woody perennials leads to the generation of potential agroforestry residues. The conventional treatment of agroforestry waste includes landfilling, thermal management, and decomposition which is accompanied with their own share of disadvantages. The ample amount of residues and products needs effective management to reap the economic and environmental benefits. The channel of waste collection, transportation, and recycle or valorization into products like biofuel, fertilizers, biochar, industrial chemicals is essential to maintain a circular sustainable bioeconomy. Global market value of biowaste to bioenergy (BtB) technology is roughly US $25.32 billion and is projected to enhance to US $40 billion by 2023. Employment of an appropriate pretreatment technology such as fermentation, hydrolysis, gasification etc. is going to elevate the degree of valorization along with surpassing the mobilization barrier. The sustainability assessment of the management process can be achieved with multiple models including technoeconomic analysis, life cycle assessment and multi criteria approach which are dependent on both hard and soft indices. Additionally, the loopholes of the agroforestry sectors would be managed by the introduction of appropriate policies which are undertaken globally by the Orlando and Lugo declarations, food and agriculture organization, Millennium Development Goals, Global Research Alliance and Guidelines for Sustainable Agriculture and Rural Development. The present review envisaged the agroforestry waste management strategy and its sustainability assessment primarily based upon Social, Economic and Environmental parameters without tormenting the future generations.


Assuntos
Agricultura Florestal , Gerenciamento de Resíduos , Agricultura , Biocombustíveis , Reciclagem
17.
J Ind Microbiol Biotechnol ; 38(4): 503-11, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20686914

RESUMO

An alkalotolerant Pseudomonas strain was enriched and isolated from effluent of the pulp and paper industry. This strain was able to degrade dibenzofuran and utilize it as a sole source of energy and carbon. The GC-MS based detection of various intermediary metabolites of biodegradation suggested the involvement of angular as well as lateral pathway of dibenzofuran biodegradation. The GC-MS based detection of various intermediary metabolites of biodegradation suggested the involvement of angular as well as lateral pathway of dibenzofuran biodegradation. This diverse dioxygenation property of the strain allowed it to utilize various recalcitrant chlorinated xenobiotics and PAHs compounds. This strain showed optimum utilization (~85%) of dibenzofuran (200 mg l⁻¹) within 36 h at pH 10 at 40 °C. The growth of the strain was supported by a wide range of environmental conditions such as temperature, pH, and concentration of dibenzofuran, suggesting that it can be used for in situ bioremediation of dioxin-like compound.


Assuntos
Benzofuranos/metabolismo , Pseudomonas/metabolismo , Biodegradação Ambiental , Dioxinas/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Concentração de Íons de Hidrogênio , Pseudomonas/crescimento & desenvolvimento , Pseudomonas/isolamento & purificação
18.
Environ Pollut ; 269: 116176, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33307397

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) such as pyrene are universal contaminants existing in the environment which have known cancer-causing and mutagenic characteristics. A psychrophilic bacterial strain Shewanella sp. ISTPL2 was isolated from the sediment sample collected from the Pangong lake, Jammu & Kashmir, India. In our previous study, the pyrene degradation potential of the ISTPL2 strain was studied in both mineral salt media as well as in soil artificially spiked with different concentrations of pyrene. Whole-genome sequencing of ISTPL2 strain in the current study highlighted the key genes of pyrene metabolism, including alcohol dehydrogenase and ring hydroxylating dioxygenase alpha-subunit. Pyrene cytotoxicity was evaluated on HepG2, a human hepato-carcinoma cell line. The cytotoxicity of the organic extract decreased with the increasing duration of bacterial treatment. To develop a more sustainable biodegradation approach, the potential impacts were evaluated for human health and ecosystem using life-cycle assessment (LCA) following the ReCiPe methodology for the considered PAH. The results implemented that global warming potential (GWP) had the highest impact, whereas both ecotoxicity and human toxicity had least from this study.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Shewanella , Animais , Biodegradação Ambiental , Ecossistema , Humanos , Índia , Estágios do Ciclo de Vida , Pirenos/toxicidade , Shewanella/genética
19.
Bioresour Technol ; 320(Pt B): 124439, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33246798

RESUMO

The strain Burkholderia sp. ISTR5 (R5) was studied for polyhydroxyalkanoate (PHA) production on Kraft lignin (KL) and lignosulfonate (LS) as substrates. During the initial screening, the maximum PHA mass fraction in biomass produced on KL and LS was 23% and 18%, respectively, at 96 h. PHA production on KL was further optimized using the Box-Behnken Design (BBD) model of Response Surface Methodology (RSM). After optimization, a 42.5% increase in PHA production and a 32.2% increase in the total cell biomass was observed. PHA was characterized by GC-MS, TEM, FTIR, NMR, and fluorescence microscopy. It was found to be a small chain length PHA with a copolymer of poly (hydroxybutyrate-co-hydroxyvalerate) (PHBV). The degradation of PHBV was also studied using this strain; it was observed that R5 completely degraded PHBV in 120 h. Genomic and proteomic analysis of R5 revealed numerous enzymes for the metabolism of lignin degradation and PHA production.


Assuntos
Poli-Hidroxialcanoatos , Proteogenômica , Biomassa , Lignina , Poliésteres , Proteômica
20.
J Hazard Mater ; 409: 124496, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33187797

RESUMO

Phthalates are a group of emerging xenobiotic compounds commonly used as plasticizers. In recent times, there has been an increasing concern over the risk of phthalate exposure leading to adverse effects to human health and the environment. Therefore, it is necessary to not only understand the current status of phthalate pollution, their sources, exposure routes and health impacts, but also identify remediation technologies for mitigating phthalate pollution. Present review article aims to inform its readers about the ever increasing data on health burdens posed by phthalates and simultaneously highlights the recent advancements in research to alleviate phthalate contamination from environment. The article enumerates the major phthalates in use today, traces their environmental fate, addresses their growing health hazard concerns and largely focus on to provide an in-depth understanding of the different physical, chemical and biological treatment methods currently being used or under research for alleviating the risk of phthalate pollution, their challenges and the future research perspectives.

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