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1.
Ecotoxicol Environ Saf ; 208: 111621, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396141

RESUMO

The study explored the polycyclic aromatic hydrocarbon tolerance of indigenous biosurfactant producing microorganisms. Three bacterial species were isolated from crude oil contaminated sites of Haldia, West Bengal. The three species were screened for biosurfactant production and identified by 16S rRNA sequencing as Brevundimonas sp. IITISM 11, Pseudomonas sp. IITISM 19 and Pseudomonas sp. IITISM 24. The strains showed emulsification activities of 51%, 57% and 63%, respectively. The purified biosurfactants were characterised using FT-IR, GC-MS and NMR spectroscopy and found to have structural similarities to glycolipopeptides, cyclic lipopeptides and glycolipids. The biosurfactants produced were found to be stable under a wide range of temperature (0-100 °C), pH (4-12) and salinity (up to 20% NaCl). Moreover, the strains displayed tolerance to high concentrations (275 mg/L) of anthracene and fluorene and showed a good amount of cell surface hydrophobicity with different hydrocarbons. The study reports the production and characterisation of biosurfactant by Brevundimonas sp. for the first time. Additionally, the kinetic parameters of the bacterial strains grown on up to 300 mg/L concentration of anthracene and fluorene, ranged between 0.0131 and 0.0156 µmax (h-1), while the Ks(mg/L) ranged between 59.28 and 102.66 for Monod's Model. For Haldane-Andrew's model, µmax (h-1) varied between 0.0168 and 0.0198. The inhibition constant was highest for Pseudomonas sp. IITISM 19 on anthracene and Brevundimonas sp. IITISM 11 on fluorene. The findings of the study suggest that indigenous biosurfactant producing strains have tolerance to high PAH concentrations and can be exploited for bioremediation purposes.


Assuntos
Antracenos/metabolismo , Biodegradação Ambiental , Fluorenos/metabolismo , Tensoativos/metabolismo , Antracenos/química , Bactérias/metabolismo , Fluorenos/química , Glicolipídeos , Hidrocarbonetos/metabolismo , Cinética , Petróleo/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Pseudomonas/metabolismo , RNA Ribossômico 16S/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Tensoativos/química
2.
Curr Genomics ; 21(5): 343-362, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33093798

RESUMO

Introduction: Plants do not grow in isolation, rather they are hosts to a variety of microbes in their natural environments. While, few thrive in the plants for their own benefit, others may have a direct impact on plants in a symbiotic manner. Unraveling plant-microbe interactions is a critical component in recognizing the positive and negative impacts of microbes on plants. Also, by affecting the environment around plants, microbes may indirectly influence plants. The progress in sequencing technologies in the genomics era and several omics tools has accelerated in biological science. Studying the complex nature of plant-microbe interactions can offer several strategies to increase the productivity of plants in an environmentally friendly manner by providing better insights. This review brings forward the recent works performed in building omics strategies that decipher the interactions between plant-microbiome. At the same time, it further explores other associated mutually beneficial aspects of plant-microbe interactions such as plant growth promotion, nitrogen fixation, stress suppressions in crops and bioremediation; as well as provides better insights on metabolic interactions between microbes and plants through omics approaches. It also aims to explore advances in the study of Arabidopsis as an important avenue to serve as a baseline tool to create models that help in scrutinizing various factors that contribute to the elaborate relationship between plants and microbes. Causal relationships between plants and microbes can be established through systematic gnotobiotic experimental studies to test hypotheses on biologically derived interactions. Conclusion: This review will cover recent advances in the study of plant-microbe interactions keeping in view the advantages of these interactions in improving nutrient uptake and plant health.

3.
Cureus ; 12(8): e9506, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32775114

RESUMO

There has been a high incidence of thromboembolic diseases in patients with coronavirus disease 2019 (COVID-19) pneumonia. We present a case of a healthy 32-year-old male with no past medical history who presented with shortness of breath, tested positive for COVID-19, and was found to have a large acute saddle pulmonary embolism.

4.
Bioresour Technol ; 304: 123003, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32081446

RESUMO

Lignocellulosic biomass is the most plentiful renewable biomolecule and an alternative bioresource for the production of biofuels and biochemicals in biorefineries. But biomass recalcitrance is a bottleneck in their usage, thus necessitating their pretreatment for hydrolysis. Most pretreatment technologies, result in toxic by-products or have lower yield. Ionic liquids (ILs) have successfully advanced as 'greener and recyclable' alternatives to volatile organic solvents for lignocellulosic biomass dissolution. This review covers recent developments made in usage of IL-based techniques with focus on biomass breakdown mechanism, process parameter design, impact of cation and anion groups, and the advantageous impact of ILs on the subsequent processing of the fractionated biomass. Progress and barriers for large-scale commercial usage of ILs in emerging biorefineries were critically evaluated using the principles of economies of scale and green chemistry in an environmentally sustainable way.


Assuntos
Líquidos Iônicos , Biocombustíveis , Biomassa , Hidrólise , Lignina
5.
Chemosphere ; 240: 124944, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726591

RESUMO

The present study explores the potential of two chromium tolerant and plant growth promoting bacterial strains, Klebsiella sp. and Enterobacter sp. in luxuriant growth of tomato plants under chromium stress conditions. For the assessment of potentiality of the two selected strains, a pot scale experiment was setup with tomato plant under different levels of chromium contamination. In pot experiment, different plant growth parameters, oxidative stress tolerance and chromium bioremediation potential were studied upon inoculation of the selected bacterial strains. The results of pot experiment showed that both the strains were effective in promotion of plant growth and enhanced the plant biomass but Enterobacter sp. was more prominent in enhancement of root length, shoot length, fresh and dry weight, and nutrient uptake in tomato plant. The enhancement of enzymes to combat oxidative stress in tomato plant under chromium stress was also observed for both the strains. Both strains enhanced the levels of superoxide dismutase, catalase, peroxidase, total phenolic, and ascorbic acid in tomato plant under different levels of chromium stress conditions. The chromium phytoremediation potential of tomato plant upon inoculation of both the strains was also studied. The results of phytoremediation showed greater chromium accumulation in roots with poor translocation in shoot upon inoculation of Klebsiella sp. while no significant enhancement in chromium uptake by tomato plant was observed on inoculation of Enterobacter sp. compared to control. Thus, these two strains can effectively be used in luxuriant growth of tomato plant under metal stress conditions.


Assuntos
Cromo/toxicidade , Enterobacter/fisiologia , Klebsiella/fisiologia , Lycopersicon esculentum/fisiologia , Poluentes do Solo/toxicidade , Biodegradação Ambiental , Biomassa , Catalase/metabolismo , Enterobacter/metabolismo , Klebsiella/metabolismo , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/microbiologia , Estresse Oxidativo , Desenvolvimento Vegetal , Raízes de Plantas/metabolismo , Superóxido Dismutase/metabolismo
6.
Sci Rep ; 9(1): 10455, 2019 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-31320739

RESUMO

It is reported that coal consumption in the Asia-Pacific region is going to increase to about 87.2 percent by 2035. Management of coal combustion residues (CCRs) generated by industries is a major bottleneck towards handling the repercussions of coal usage. The present study investigates a management technique for these potentially hazardous wastes by means of vermicomposting. In the present investigation, studies were made on the effects of various concentrations of vermicomposted fly ash (VCF) added to agricultural soil, on the growth and yield of tomato (Lycopersicon esculentum Mill.) and brinjal (Solanum melongena L.) plants. The toxicity of trace elements in VCF were estimated using coefficient of pollution and potential ecological risk index, which revealed no apparent risks to the environment. A gradual increase in VCF concentrations in the agricultural soil improved the physico-chemical properties, enzymatic activities, microbial biomass, carbon and microbial population upto 90 days after sowing of seeds. The VCF amendments significantly (p < 0.05) improved the soil quality (2.86% nitrogen and 1.05% Phosphorous) and germination percentage (82.22%) of seeds in L. esculentum and also in S. melongena. The results of this study reveal that, CCRs can be effectively managed in agriculture specially in developing economies.


Assuntos
Agricultura/métodos , Bactérias/enzimologia , Proteínas de Bactérias/metabolismo , Cinza de Carvão/farmacologia , Compostagem/métodos , Oligoquetos/química , Desenvolvimento Vegetal/efeitos dos fármacos , Solo/química , Animais , Biomassa , Cinza de Carvão/química , Fertilizantes/análise
7.
J Hazard Mater ; 377: 391-398, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31173990

RESUMO

Prevalence of metal pollutants exerts negative effects on human health and environment, thus propounding an urgent need for a safer substitute. This study was conducted to compare the chromium bioremediation and plant growth promotion ability of two bacterial strains, Klebsiella sp. strain CPSB4 (MH266218) and Enterobacter sp. strain CPSB49 (MH532567), isolated from the rhizospheric soils. A pot scale experiment was setup with Helianthus annuus (L.) as a test plant to compare the efficiency of both isolates in enhancement of plant growth, nutrients uptake, anti-oxidative enzymes production, lipid peroxidation, and chromium bioremediation. Inoculation of strains, CPSB4 and CPSB49 enhanced plant biomass, plant growth, nutrient uptake, anti-oxidative enzymes, and chromium bioremediation, while reduction in lipid peroxidation was observed compared to uninoculated control under chromium stress. The maximum increase in plant growth and nutrient uptake was found in treatments inoculated with CPSB49, while maximum chromium uptake by sunflower was observed in treatments inoculated with CPSB4. Moreover, an increase in anti-oxidative enzyme production and decrease in lipid peroxidation was observed on inoculation of the selected strains. Thus, the strains Klebsiella sp. and Enterobacter sp. can be effectively used in chromium bioremediation and plant growth promotion under chromium stress conditions.


Assuntos
Biodegradação Ambiental , Compostos de Cromo/metabolismo , Enterobacter/metabolismo , Helianthus/metabolismo , Helianthus/microbiologia , Klebsiella/metabolismo , Poluentes do Solo/metabolismo , Antioxidantes/metabolismo , Biomassa , Peroxidação de Lipídeos , Estresse Oxidativo , Desenvolvimento Vegetal/efeitos dos fármacos , Raízes de Plantas/microbiologia , Microbiologia do Solo
8.
Chemosphere ; 225: 479-489, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30897471

RESUMO

Endosulfan is a broad spectrum insecticide used in agriculture for protection of various food and non-food crops. It is persistent in nature and hence found in soil, air and water. The potential use of plants and microorganisms for the removal of endosulfan from soil was studied. Helianthus annuus plant was grown in soil spiked with 5, 10, 25 and 50 mg kg-1 concentrations of endosulfan and inoculated with plant growth promoting rhizobacterial strains Paenibacillus sp. IITISM08, Bacillus sp. PRB77 and Bacillus sp. PRB101 for 40, 80 and 120 days. Potential of plant for endosulfan uptake was evaluated by investigating the endosulfan levels in plant tissues (root and shoot). The results indicated that endosulfan accumulation followed the pattern of root > shoot as well as decrease in uptake of endosulfan in root and shoot of a plant grown in bacterial inoculated soil as compared to un-inoculated soil. Bacterial inoculation had a positive effect on endosulfan degradation. Maximum degradation of 92% at 5 mg kg-1 of endosulfan in soil was observed on inoculation with PRB101 after 120 days of inoculation. The results showed that plant growth promoting bacteria enhances plant biomass production. Lipid peroxidation was also estimated by determining the malondialdehyde (MDA) production, which is a biomarker of oxidative damage. Decrease in MDA formation by root and leaves of plants grown in the bacteria inoculated plant was also observed. The results suggested the effectiveness of plant growth promoting rhizobacteria to boost accumulation potential, biomass production and enhance remediation of endosulfan contaminated soil.


Assuntos
Bacillus/metabolismo , Biodegradação Ambiental , Endossulfano/metabolismo , Helianthus/metabolismo , Inseticidas/metabolismo , Paenibacillus/metabolismo , Poluentes do Solo/metabolismo , Inoculantes Agrícolas , Agricultura , Biomassa , Produtos Agrícolas/metabolismo , Endossulfano/análise , Helianthus/crescimento & desenvolvimento , Inseticidas/análise , Raízes de Plantas/metabolismo , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise
9.
Ecotoxicol Environ Saf ; 168: 315-323, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30390530

RESUMO

Endosulfan contaminated soil has become an important risk to the environment and human health worldwide. In the present study, endosulfan tolerant bacterial strain Delftia lacustris IITISM30 and Klebsiella aerogenes IITISM42 were isolated from pesticide stressed agricultural soil and tested for plant growth promoting activities. A pot experiment was performed using Helianthus annuus, grown in soil supplemented with endosulfan and inoculated with pure and consortium of bacterial strain IITISM30 and IITISM42. Inoculation increased plant biomass production and endosulfan degradation, maximum degradation (90% at 5 mg kg-1 of soil) was observed by inoculation with a consortium of bacterial strain IITISM30 and IITISM42. Moreover, there was significantly less endosulfan accumulation was observed in roots and shoots of bacterial inoculated plants as compared to uninoculated plants. Decrease in production of malonialdehyde (MDA) was noticed on inoculation of a bacterial strain. The study demonstrated that inoculation of a consortium of endosulfan tolerant plant growth promoting bacterial isolates could more effectively remediate endosulfan contaminated soils and decrease endosulfan residues in plants, than individual strains. Moreover, it revealed that combined use of H. annuus and endosulfan tolerant bacterial isolates IITISM30 and IITISM42 has great potential for remediating endosulfan contaminated soil.


Assuntos
Biodegradação Ambiental , Delftia , Endossulfano/isolamento & purificação , Enterobacter aerogenes , Helianthus/metabolismo , Poluentes do Solo/isolamento & purificação , Inoculantes Agrícolas , Biomassa , Helianthus/microbiologia , Peroxidação de Lipídeos , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Solo/química , Microbiologia do Solo
10.
Sci Rep ; 8(1): 4860, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29559691

RESUMO

Contamination of agricultural soil with heavy metals has become a serious concern worldwide. In the present study, Cr6+ resistant plant growth promoting Pseudomonas sp. (strain CPSB21) was isolated from the tannery effluent contaminated agricultural soils and evaluated for the plant growth promoting activities, oxidative stress tolerance, and Cr6+ bioremediation. Assessment of different plant growth promotion traits, such as phosphate solubilization, indole-3-acetic acid production, siderophores, ammonia and hydrogen cyanide production, revealed that the strain CPSB21 served as an efficient plant growth promoter under laboratory conditions. A pot experiment was performed using sunflower (Helianthus annuus L.) and tomato (Solanum lycopersicum L.) as a test crop. Cr6+ toxicity reduced plant growth, pigment content, N and P uptake, and Fe accumulation. However, inoculation of strain CPSB21 alleviated the Cr6+ toxicity and enhanced the plant growth parameters and nutrient uptake. Moreover, Cr toxicity had varied response on oxidative stress tolerance at graded Cr6+ concentration on both plants. An increase in superoxide dismutase (SOD) and catalase (CAT) activity and reduction in malonialdehyde (MDA) was observed on inoculation of strain CPSB21. Additionally, inoculation of CPSB21 enhanced the uptake of Cr6+ in sunflower plant, while no substantial enhancement was observed on inoculation in tomato plant.


Assuntos
Cromo/toxicidade , Pseudomonas/metabolismo , Poluentes do Solo/toxicidade , Agricultura , Biodegradação Ambiental , Biomassa , Catalase/metabolismo , Helianthus/crescimento & desenvolvimento , Lycopersicon esculentum/crescimento & desenvolvimento , Metais Pesados/toxicidade , Estresse Oxidativo , Desenvolvimento Vegetal , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Solo/química , Microbiologia do Solo , Poluentes do Solo/efeitos adversos , Superóxido Dismutase/metabolismo
11.
Chemosphere ; 192: 318-327, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29117590

RESUMO

In this study, an effort was made to identify an efficient phosphate solubilizing bacterial strain from chromium contaminated agricultural soils. Based on the formation of a solubilized halo around the colonies on Pikovskaya's agar amended with chromium (VI), 10 strains were initially screened out. Out of 10, strain CPSB4, which showed significantly high solubilization zone at different chromium concentrations, was selected for further study. The strain CPSB4 showed significant plant growth promotion traits with chromium (VI) stress under in-vitro conditions in broth. The plant growth promotion activities of the strain decreased regularly, but were not completely lost with the increase in concentration of chromium up to 200 mg L-1. On subjected to FT-IR analysis, the presence of the functional group, indicating the organic acid aiding in phosphate solubilization was identified. At an optimal temperature of 30 °C and pH 7.0, the strain showed around 93% chromium (VI) reduction under in-vitro conditions in broth study. In soil condition, the maximum chromium (VI) reduction obtained was 95% under in-vitro conditions. The strain CPSB4 was identified as Klebsiella sp. on the basis of morphological, biochemical and 16S rRNA gene sequencing. This study shows that the diverse role of the bacterial strain CPSB4 would be useful in the chromium contaminated soil as a good bioremediation and plant growth promoting agent as well.


Assuntos
Biodegradação Ambiental , Cromo/farmacologia , Klebsiella/metabolismo , Fosfatos/metabolismo , Poluentes do Solo/metabolismo , Klebsiella/química , Klebsiella/genética , Klebsiella/isolamento & purificação , Fosfatos/química , Desenvolvimento Vegetal/efeitos dos fármacos , Solo/química , Microbiologia do Solo , Poluentes do Solo/farmacologia , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier
12.
Environ Sci Pollut Res Int ; 25(6): 5668-5680, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29230644

RESUMO

The study aimed to identify an effective phosphate-solubilizing and organochlorine pesticide-tolerant bacterial strain(s). A total of 50 phosphate-solubilizing bacterial (PSB) strains were isolated from pesticide-stressed soil. Ten isolates showing higher solubilization were selected for organochlorine pesticides (endosulfan, aldrin, and lindane) tolerance. The strain IITISM08 showed the maximum potential of phosphorous solubilization in Pikovaskya agar medium (solubilization index = 3.2) and in broth medium (348 ± 2 µg mL-1) and tolerated up to 250 µg mL-1 of organochlorine pesticides. During phosphorous solubilization, the presence of functional group and organic acid production were also observed using FT-IR and HPLC. The plant growth-promoting (PGP) traits of the strain IITISM08 was highly inhibited in presence of endosulfan among the three organochlroine pesticides. The strain IITISM08 degraded aldrin (79%), lindane (68%), and endosulfan (51%) at a concentration of 50 µg mL-1. The strain IITISM08 was identified using 16S rDNA gene sequencing as Paenibacillus sp. (IITISM08). The study revealed that the strain IITISM08 can be used as PGP candidate even under organochlorine pesticide-stressed condition.


Assuntos
Hidrocarbonetos Clorados/análise , Paenibacillus/metabolismo , Praguicidas/análise , Fosfatos/metabolismo , Microbiologia do Solo , Poluentes do Solo/análise , Biodegradação Ambiental , Brassica/crescimento & desenvolvimento , Hidrocarbonetos Clorados/toxicidade , Lycopersicon esculentum/crescimento & desenvolvimento , Paenibacillus/efeitos dos fármacos , Paenibacillus/genética , Praguicidas/toxicidade , Fosfatos/química , Rizosfera , Solo/química , Poluentes do Solo/toxicidade , Solubilidade
13.
World J Microbiol Biotechnol ; 33(1): 9, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27858338

RESUMO

The presence of heavy metals in the soil is a matter of growing concern due to their toxic and non-biodegradable nature. Lack of effectiveness of various conventional methods due to economic and technical constraints resulted in the search for an eco-friendly and cost-effective biological techniques for heavy metal removal from the environment. Until now, phytoremediation has emerged as an innovative technique to address the problem. However, the efficiency of phytoremediation process is hindered under the high metal concentration conditions. Hence, phosphate solubilizing microbes (PSM) assisted phytoremediation technique is gaining more insight as it can reduce the contamination load even under elevated metal stressed conditions. These microbes convert heavy metals into soluble and bioavailable forms, which consequently facilitate phytoremediation. Several studies have reported that the use of microbial consortium for remediation is considered more effective as compared to single strain pure culture. Therefore, this review paper focuses on the current trends in research related to PSM mediated uptake of heavy metal by plants. The efficiency of PSM consortia in enhancing the phytoremediation process has also been reviewed. Moreover, the role of phosphatase enzymes in the mineralization of organic forms of phosphate in soil is further discussed. Biosurfactant mediated bioremediation of metal polluted soils is a matter of extensive research nowadays. Hence, the recent advancement of using biosurfactants in enhanced phytoremediation of metal stressed soils is also described.


Assuntos
Bactérias/metabolismo , Metais Pesados/metabolismo , Fosfatos/química , Plantas/microbiologia , Bactérias/enzimologia , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Metais Pesados/toxicidade , Consórcios Microbianos , Monoéster Fosfórico Hidrolases/metabolismo , Microbiologia do Solo
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