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1.
Environ Monit Assess ; 195(7): 820, 2023 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-37289326

RESUMEN

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).


Asunto(s)
Antioxidantes , Diatomeas , Humanos , Antioxidantes/metabolismo , Diatomeas/metabolismo , Superóxido Dismutasa/metabolismo , Peróxido de Hidrógeno , Monitoreo del Ambiente , Catalasa/metabolismo , Ascorbato Peroxidasas/metabolismo , Estrés Oxidativo
2.
Environ Sci Pollut Res Int ; 29(26): 38950-38971, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35304714

RESUMEN

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.


Asunto(s)
Dióxido de Carbono , Combustibles Fósiles , Bacterias/metabolismo , Carbono/metabolismo , Dióxido de Carbono/análisis , Secuestro de Carbono , Estudios Prospectivos
3.
Chemosphere ; 287(Pt 3): 132321, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34563778

RESUMEN

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.


Asunto(s)
Agricultura Forestal , Administración de Residuos , Agricultura , Biocombustibles , Reciclaje
4.
Environ Res ; 192: 110277, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33069701

RESUMEN

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.


Asunto(s)
Bacillus , Matriz Extracelular de Sustancias Poliméricas , Bacillus/genética , Genómica , Suelo , Espectroscopía Infrarroja por Transformada de Fourier
5.
Environ Pollut ; 269: 116176, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33307397

RESUMEN

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.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Shewanella , Animales , Biodegradación Ambiental , Ecosistema , Humanos , India , Estadios del Ciclo de Vida , Pirenos/toxicidad , Shewanella/genética
6.
Bioresour Technol ; 320(Pt B): 124439, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33246798

RESUMEN

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.


Asunto(s)
Polihidroxialcanoatos , Proteogenómica , Biomasa , Lignina , Poliésteres , Proteómica
7.
J Hazard Mater ; 409: 124496, 2021 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-33187797

RESUMEN

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.

8.
Environ Res ; 191: 110064, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32846180

RESUMEN

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.


Asunto(s)
Matriz Extracelular de Sustancias Poliméricas , Metales Pesados , Adsorción , Matriz Extracelular de Sustancias Poliméricas/química , Concentración de Iones de Hidrógeno , India , Cinética , Metales Pesados/análisis
9.
Trends Biotechnol ; 38(9): 963-975, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32818444

RESUMEN

Burkholderia, a bacterial genus comprising more than 120 species, is typically reported to inhabit soil and water environments. These Gram-negative bacteria harbor a variety of aromatic catabolic pathways and are thus potential organisms for bioremediation of sites contaminated with aromatic pollutants. However, there are still substantial gaps in our knowledge of these catabolic processes that must be filled before these pathways and organisms can be harnessed for biotechnological applications. This review presents recent discoveries on the catabolism of monoaromatic and polycyclic aromatic hydrocarbons, as well as of heterocyclic compounds, by a diversity of Burkholderia strains. We also present a perspective on the beneficial features of Burkholderia spp. and future directions for their potential utilization in the bioremediation and bioconversion of aromatic compounds.


Asunto(s)
Biodegradación Ambiental , Burkholderia/metabolismo , Hidrocarburos Policíclicos Aromáticos/metabolismo , Contaminantes del Suelo/metabolismo , Burkholderia/genética , Compuestos Orgánicos/metabolismo , Compuestos Orgánicos/toxicidad , Hidrocarburos Policíclicos Aromáticos/toxicidad , Microbiología del Suelo , Contaminantes del Suelo/toxicidad
10.
Int J Mol Sci ; 21(14)2020 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-32664313

RESUMEN

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.


Asunto(s)
ADN Ambiental/genética , Monitoreo del Ambiente/métodos , ARN/genética , Estrés Fisiológico/genética , Animales , Enfermedad Crónica , Ambiente , Exposoma , Humanos , Medición de Riesgo
11.
J Cancer Res Clin Oncol ; 146(11): 2777-2815, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32705365

RESUMEN

PURPOSE: Nuclear respiratory factor 1 (NRF1) drives estrogen-dependent breast tumorigenesis. Herein we examined the impact of NRF1 activity on the aggressiveness and disparate molecular signature of breast cancer in Black, White, Asian, and Hispanic women. METHODS: NRF1 activity by transcription factor target enrichment analysis and causal NRF1-target gene signatures by Bayesian Network Inference with Java Objects (BANJO) and Markov Chain Monte Carlo (MCMC)-based gene order were examined in The Cancer Genome Atlas (TCGA) breast cancer cohorts. RESULTS: We are the first to report increased NRF1 activity based on its differential effects on genome-wide transcription associated with luminal A and B, HER2+ and triple-negative (TN) molecular subtypes of breast cancer in women of different race/ethnicity. We observed disparate NRF1 motif-containing causal gene signatures unique to Black, White, Asian, and Hispanic women for luminal A breast cancer. Further gene order searches showed molecular heterogeneity of each subtype of breast cancer. Six different gene order sequences involving CDK1, HMMR, CCNB2, CCNB1, E2F1, CREB3L4, GTSE1, and LMNB1 with almost equal weight predicted the probability of luminal A breast cancer in whites. Three different gene order sequences consisting of CCNB1 and GTSE1, and CCNB1, LMNB1, CDK1 or CASP3 predicted almost 100% probability of luminal B breast cancer in whites; CCNB1 and LMNB1 or GTSE predicted 100% HER2+ breast cancer in whites. GTSE1 and TUBA1C combined together predicted 100% probability of developing TNBC in whites; NRF1, TUBA1B and BAX with EFNA4, and NRF1 and BTRC predicated 100% TNBC in blacks. High expressor NRF1 TN breast tumors showed unfavorable prognosis with a high risk of breast cancer death in white women. CONCLUSION: Our findings showed how sensitivity to high NRF1 transcriptional activity coupled with its target gene signatures contribute to racial differences in luminal A and TN breast cancer subtypes. This knowledge may be useful in personalized intervention to prevent and treat this clinically challenging problem.


Asunto(s)
Neoplasias de la Mama/etnología , Neoplasias de la Mama/genética , Factor Nuclear 1 de Respiración/genética , Transcriptoma/genética , Adulto , Femenino , Humanos , Persona de Mediana Edad
12.
Sci Total Environ ; 731: 139074, 2020 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-32417476

RESUMEN

The environment of a high altitude brackish water lake presents an unprecedented reservoir for the microbial community with adaptability towards surviving stressful conditions. Pangong lake is a high altitude brackish water lake of the Himalayas situated in the eastern part of Ladakh (Indian Tibet), at the height of 4250 m above the sea level. Shotgun metagenomics sequencing of Pangong Lake sediments was performed to examine the taxonomic diversity and functional adaptations of the resident psychrophilic and psychrotolerant microbial communities of the lake (September; a temperature of ±10 °C). Proteobacteria was the most prominent phylum, and Methylophaga, Halomonas, and Marinobacter were mainly abundant at the genus level. Enzyme pathways responsible for methane metabolism, nitrogen metabolism, sulfur reduction, benzoate, and xylene degradation appeared to be complete in the metagenomic dataset. Stress response genes responsible for adaption to pH, cold, salt tolerance, osmotic stress, and oxidative stress were also found in abundance in the metagenome. We compared the Pangong lake metagenome sample to sediments and water samples from three different aquatic habitats, namely saline lake, freshwater lakes and marine ecosystem using MG-RAST server against RefSeq and Subsystem databases. The Pangong lake microbial community contains six unique genera. Regression analysis using metagenome samples suggested that Pangong lake was most closely related to the Trophic South Pacific Ocean (R2 = 0.971) and Socompa lake ecosystem (R2 = 0.991) at phylum and functional level II, respectively. Our study signifies that the functional metabolic potentiality of Pangong lake is strongly influenced by the taxonomic structure and environmental conditions. We are reporting the metagenome of the sediment sample of the Pangong lake, which unveils the microbial diversity and their functional potential.


Asunto(s)
Lagos , Metagenoma , Bacterias/genética , Sedimentos Geológicos , Metagenómica , Océano Pacífico , Filogenia , Tibet
13.
Bioresour Technol ; 307: 123262, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32247278

RESUMEN

The current study presents a comprehensive analysis of the potential of actinobacterium Zhihengliuella sp. ISTPL4 and different composite materials for the removal of hexavalent chromium [Cr (VI)]. Genome analysis of strain indicated the presence of several oxidoreductases which includes chromate reductase, nitrate reductase, thioredoxin, superoxide dismutase and hydrogenase are other major candidate genes. Catalytic calcite-based bio-composite material was absorbed on biochar had highest Cr removal efficiency. The main mechanism involved in Cr biosorption by this strain was explained by the Langmuir isotherm model; under equilibrium conditions the maximum adsorption was observed 49 ± 0.3 mgg-1. Kinetic studies showed that biosorption of Cr (VI) by this strain was a rate-limiting step and followed a pseudo-second-order kinetics (R2 = 0.99). SEM analysis is in line with EDX result indicating highest Cr removal by calcined biochar. MTT assay shown that the bacteria successfully convert toxic Cr (VI) to comparatively less toxic form such as Cr (III).


Asunto(s)
Carbonato de Calcio , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Cromo , Cinética
14.
Bioresour Technol ; 307: 123193, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32203868

RESUMEN

Production of biodiesel from lipids of Serratia sp. ISTD04 by lipase of Pseudomonas sp. ISTPL3 immobilised on biocomposite materials to increase the enzyme stability and reusability was studied. Lipase extracted, partially purifiedand immobilized onto activated biochar, impregnated with calcite obtained from biomineralization-based conversion of CO2 from ISTD04, and bioactive ceramics materials, Na2Ca2Si3O9 prepared by chemical process. The composition, structure and texture of biocomposite materials determined by SEM and EDS methods. The composition of synthesized biodiesel was determined by GC-MS. The results imply that the immobilized lipase on activated biochar impregnated with calcite gave the maximum yield of fatty acid methyl esters (FAME:97.41%) followed by immobilized lipase on biochar (FAME:94.91), immobilized lipase on glass-ceramic (FAME:91.50%) and NaOH (FAME:85.63%). The reusability of lipase immobilized on activated biochar impregnated with calcite retained 75.11%and 50% catalytic activity after 5 and 10 cycles of transesterification reaction, respectively.


Asunto(s)
Biocombustibles , Lipasa , Dióxido de Carbono , Enzimas Inmovilizadas , Esterificación , Lípidos , Serratia
15.
Sci Total Environ ; 716: 137116, 2020 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-32059310

RESUMEN

The current review explores the potential application of algal biomass for the production of biofuels and bio-based products. The variety of processes and pathways through which bio-valorization of algal biomass can be performed are described in this review. Various lipid extraction techniques from algal biomass along with transesterification reactions for biodiesel production are briefly discussed. Processes such as the pretreatment and saccharification of algal biomass, fermentation, gasification, pyrolysis, hydrothermal liquefaction, and anaerobic digestion for the production of biohydrogen, bio-oils, biomethane, biochar (BC), and various bio-based products are reviewed in detail. The biorefinery model and its collaborative approach with various processes are highlighted for the production of eco-friendly, sustainable, and cost-effective biofuels and value-added products. The authors also discuss opportunities and challenges related to bio-valorization of algal biomass and use their own perspective regarding the processes involved in production and the feasibility to make algal research a reality for the production of biofuels and bio-based products in a sustainable manner.


Asunto(s)
Biocombustibles , Biomasa , Fermentación , Microalgas , Aceites de Plantas , Plantas
16.
Bioresour Technol ; 296: 122275, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31683109

RESUMEN

The present study intends to evaluate the potential of co-digestion for utilizing Organic fraction of Municipal Solid Waste (OFMSW) and sewage sludge (SS) for enhanced biogas production. Metagenomic analysis was performed to identify the dominant bacteria, archaea and fungi, changes in their communities with time and their functional roles during the course of anaerobic digestion (AD). The cumulative biogas yield of 586.2 mL biogas/gVS with the highest methane concentration of 69.5% was observed under an optimum ratio of OFMSW:SS (40:60 w/w). Bacteria and fungi were found to be majorly involved in hydrolysis and initial stages of AD. Probably, the most common archaea Methanosarsina sp. primarily followed the acetoclastic pathway. The hydrogenotrophic pathway was less followed as indicated by the reduction in abundance of syntrophic acetate oxidizers. An adequate understanding of microbial communities is important to manipulate and inoculate the specific microbial consortia to maximize CH4 production through AD.


Asunto(s)
Aguas del Alcantarillado , Residuos Sólidos , Anaerobiosis , Biocombustibles , Reactores Biológicos , Digestión , Redes y Vías Metabólicas , Metano
17.
Environ Sci Pollut Res Int ; 27(22): 27319-27329, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31317429

RESUMEN

The present research investigates potential of microalgae isolated from sewage treatment plant to utilize sodium bicarbonate as carbon source for CO2 sequestration and biodiesel production. Eight algal isolates were isolated from waste water of sewage treatment plant, Amity University Haryana, India. The most potent algal isolates were identified and characterized on the basis of growth and lipid content. The efficient isolates ASW1 and ASW2 were identified as Chlorella sp. and Arthronema sp. by 18srRNA and 16srRNA sequencing method. In both isolates, maximum growth was observed under 20-W fluorescent bulb (3500 flux light intensity) with continuous light cycle of 24 h at pH 9.0 and 25 °C on the 20th day of incubation period. CO2 utilization efficiency of both algal isolates were observed in terms of total CO2 consumption rate. Under optimized culture conditions, total lipid content and lipid yield was higher in Arthronema sp. (180 mg l-1; 32.14%) as compared to Chlorella sp. (98 mg l-1; 29.6%) in 50 mM NaHCO3. Transesterified lipids were analysed by GC-MS. The fatty acid methyl ester profile of Arthronema sp. was 34.42% saturated and 65.58% unsaturated fatty acid. Chlorella sp. produces 29.80% saturated and 70.20% unsaturated fatty acid. In both isolates, C16 and C18 fatty acids dominated, which is a promising component for biodiesel. Graphical abstract.


Asunto(s)
Chlorella , Microalgas , Biocombustibles , Biomasa , Dióxido de Carbono , Ácidos Grasos , India , Aguas del Alcantarillado , Aguas Residuales
18.
Environ Sci Pollut Res Int ; 27(22): 27256-27267, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31172432

RESUMEN

Polycyclic aromatic hydrocarbons (PAHs) are universal environmental contaminants of great concern with regard to their potential exposure and deleterious effect on human health. The current study is the first report of phenanthrene degradation by a psychrotolerant (15 °C), halophilic (5% NaCl), and alkalophilic (pH 8) bacterial strain Zhihengliuella sp. ISTPL4, isolated from the sediment sample of the Pangong Lake, Ladakh, Jammu and Kashmir, India. Degradation studies revealed that the optimum specific growth rate was observed at 250 ppm of phenanthrene with 81% and 87% removal of phenanthrene in 72 h and 168 h, respectively. During the degradation of phenanthrene; 9,10-dihydrophenanthrene; 1-phenanthrenecarboxylic acid; and phthalic acid were detected as intermediates. Whole-genome sequencing of strain ISTPL4 has predicted phenanthrene; 9,10-monooxygense; and epoxide hydrolase B that are involved in the phenanthrene metabolism. Phenanthrene cytotoxicity was evaluated with human hepatic carcinoma cell line (HepG2) and it was observed that the cytotoxicity decreased with increased duration of bacterial incubation and maximum cell viability was observed at 168 h (89.92%). Our results suggest, Zhihengliuella sp. ISTPL4 may promise a great potential for environmental remediation applications.


Asunto(s)
Fenantrenos/análisis , Hidrocarburos Policíclicos Aromáticos , Bacterias , Biodegradación Ambiental , India
19.
Biotechnol Biofuels ; 12: 277, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31788027

RESUMEN

BACKGROUND: Lignin is the second most abundant natural polymer on earth. Industries using lignocellulosic biomass as feedstock generate a considerable amount of lignin as a byproduct with minimal usage. For a sustainable biorefinery, the lignin must be utilized in improved ways. Lignin is recalcitrant to degradation due to the complex and heterogeneous structure. The depolymerization of lignin and its conversion into specific product stream are the major challenges associated with lignin valorization. The blend of oligomeric, dimeric and monomeric lignin-derived compounds (LDCs) generated during depolymerization can be utilized by microbes for production of bioproducts. RESULTS: In the present study, a novel bacterium Burkholderia sp. strain ISTR5 (R5), a proteobacteria belonging to class betaproteobacteria, order Burkholderiales and family Burkholderiaceae, was isolated and characterized for the degradation of LDCs. R5 strain was cultured on 12 LDCs in mineral salt medium (MSM) supplemented with individual compounds such as syringic acid, p-coumaric acid, ferulic acid, vanillin, vanillic acid, guaiacol, 4-hydroxybenzoic acid, gallic acid, benzoic acid, syringaldehyde, veratryl alcohol and catechol. R5 was able to grow and utilize all the selected LDCs. The degradation of selected LDCs was monitored by bacterial growth, total organic carbon (TOC) removal and UV-Vis absorption spectra in scan mode. TOC reduction shown in the sample contains syringic acid 80.7%, ferulic acid 84.1%, p-coumaric acid 85.9% and benzoic acid 83.2%. In UV-Vis absorption spectral scan, most of the lignin-associated peaks were found at or near 280 nm wavelength in the obtained absorption spectra. Enzyme assay for the ligninolytic enzymes was also performed, and it was observed that lignin peroxidase and laccase were predominantly expressed. Furthermore, the GC-MS analysis of LDCs was performed to identify the degradation intermediates from these compounds. The genomic analysis showed the robustness of this strain and identified various candidate genes responsible for the degradation of aromatic or lignin derivatives, detoxification mechanism, oxidative stress response and fatty acid synthesis. The presence of peroxidases (13%), laccases (4%), monooxygenases (23%), dioxygenase (44%), NADPH: quinone oxidoreductases (16%) and many other related enzymes supported the degradation of LDCs. CONCLUSION: Numerous pathway intermediates were observed during experiment. Vanillin was found during growth on syringic acid, ferulic acid and p-coumaric acid. Some other intermediates like catechol, acetovanillone, syringaldehyde and 3,4-dihydroxybenzaldehyde from the recognized bacterial metabolic pathways existed during growth on the LDCs. The ortho- and meta cleavage pathway enzymes, such as the catechol-1,2-dioxygenase, protocatechuate 3,4-dioxygenase, catechol-2,3-dioxygenase and toluene-2,3-dioxygenase, were observed in the genome. In addition to the common aromatic degradation pathways, presence of the epoxyqueuosine reductase, 1,2-epoxyphenylacetyl-CoA isomerase in the genome advocates that this strain may follow the epoxy Coenzyme A thioester pathway for degradation.

20.
Bioresour Technol ; 291: 121890, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31378447

RESUMEN

In recent impetus of phycological research, microalgae have emerged as a potential candidate for various arena of application-driven research. Omics-based tactics are used for disentangling the regulation and network integration for biosynthesis/degradation of metabolic precursors, intermediates, end products, and identifying the networks that regulate the metabolic flux. Multi-omics coupled with data analytics have facilitated understanding of biological processes and allow ample access to diverse metabolic pathways utilized for genetic manipulations making microalgal factories more efficient. The present review discusses state-of-art "Algomics" and the prospect of microalgae and their role in symbiotic association by using omics approaches including genomics, transcriptomics, proteomics and metabolomics. Microalgal based uni- and multi-omics approaches are critically analyzed in wastewater treatment, metal toxicity and remediation, biofuel production, and therapeutics to provide an imminent outlook for an array of environmentally sustainable and economically viable microalgal applications.


Asunto(s)
Microalgas/metabolismo , Animales , Genómica/métodos , Humanos , Metabolómica , Proteómica , Aguas Residuales/química
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