Publications by authors named "Asha Sahu"

6 Publications

  • Page 1 of 1

Ecotoxicological effect of TiO nano particles on different soil enzymes and microbial community.

Ecotoxicology 2021 May 1;30(4):719-732. Epub 2021 Apr 1.

ICAR- Indian Institute of Soil Science, Nabibagh, Berasia Road, Bhopal, 462038, India.

TiO nano particles (NPs) are one of the most produced nanoparticles in the world which are increasingly being released in to the soil. Soils are exposed to various level of concentration of TiO NPs, which has raised concern over the adverse influence on soil microbial community, in turn on ecosystem functions. Although, increasing number of studies on ecotoxicological effect of TiO NPs are coming up recently, however, a common conscience has yet to be reached regarding the impact of TiO NPs on soil microbial community and processes. Moreover, very few studies have targeted soil enzymes which are being considered as sensitive indicator of soil health. Therefore, the present study has been carried out to estimate the ecotoxicological effect of various doses of TiO NPs (5, 10, 20, 40, 80, 100 mg kg soil) on different soil enzymes and microbial community structure. Results revealed that soil enzyme activities and microbial biomass had a uniform trend where the value increased up to the dose of 20 mg TiO NPs kg soil and there onwards reduced drastically up to 100 mg TiO NPs kg soil dose. On the contrary, soil respiration and metabolic quotient kept increasing up to 100 mg TiO NPs kg soil dose indicating sub-lethal stress on microbial community. Nevertheless, the structure of microbial community had slightly different trend where the biomass of total phospho lipid fatty acid (PLFA), Gram positive, Gram negative bacteria, fungi, actinomyctetes and anaerobes were found to be increased up to dose of 80 mg TiO NPs kg soil, but, significantly declined at 100 mg TiO NPs kg soil dose. Furthermore, temperature effect on TiO NPs toxicity had exhibited a less negative impact at 40 °C rather than at 25 °C. In addition alteration index (AI3), an integrated indicator of C, N, P cycling of soils as well as a well-documented indicator of soil pollution, has been found to be regulated by soil respiration, clay content, anaerobe and eukaryote for AI3-Acid Phos. and by fungi to bacteria ratio, soil respiration, microbial biomass and Gram positive bacteria for AI3-Alk. Phos. Overall, the study provided valuable information regarding ecotoxicological impact of environmentally relevant concentrations of TiO NPs in clay loam soils as well as improved our perception regarding the impact of NPs on soil functioning.
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http://dx.doi.org/10.1007/s10646-021-02398-2DOI Listing
May 2021

Potential of cotton for remediation of Cd-contaminated soils.

Environ Monit Assess 2021 Mar 13;193(4):186. Epub 2021 Mar 13.

ICAR-Indian Institute of Soil Science, Nabi Bagh, Berasia Road, Bhopal, India.

The present research was conducted to study the potential of cotton for the remediation of soils contaminated with Cd, to understand the biochemical basis of its tolerance to, and to investigate the plant-microbe interaction in the rhizosphere for enhancement of phytoextraction of Cd. Cotton (Bt RCH-2) was exposed to four Cd levels (0, 50, 100, and 200 mg/kg soil) in a completely randomised design and found that the plant could tolerate up to 200 mg/kg soil. Cd stress increased the total phenol, proline, and free amino acid contents in the plant leaf tissue compared with control but inhibited basal soil respiration, fluorescein diacetate hydrolysis, and activities of several enzymes viz. dehydrogenase, phosphatases, and β-glucosidase in the soil over control. The concentration of Cd in the shoot was less than the critical concentration of 100 µg/g dry weight, and bioconcentration and translocation factors were < 1 to classify the plant as a hyperaccumulator of Cd. This was further confirmed by another experiment in which the cotton plant was exposed various higher levels of Cd (200, 400, 600, 800, and 1000 mg/kg soil). Though the concentration of Cd in the shoot was > 100 µg g dw beyond 600 mg Cd/kg soil, the bioconcentration and translocation factors were < 1. The study on plant-microbe (Aspergillus awamori) interaction revealed that the fungus did not affect the absorption of Cd by cotton. It was concluded that the cotton was classified as an excluder of Cd and therefore could be suitable for the phytostabilization of Cd-contaminated soils.
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http://dx.doi.org/10.1007/s10661-021-08976-5DOI Listing
March 2021

In situ decomposition of crop residues using lignocellulolytic microbial consortia: a viable alternative to residue burning.

Environ Sci Pollut Res Int 2021 Feb 24. Epub 2021 Feb 24.

ICAR-Indian Institute of Soil Science, Bhopal, 462038, India.

Open field burning of crop residue causes severe air pollution and greenhouse gas emission contributing to global warming. In order to seek an alternative, the current study was initiated to explore the prospective of lignocellulolytic microbes to expedite in situ decomposition of crop residues. Field trials on farmers' field were conducted in the state of Haryana and Maharashtra, to target the burning of rice and wheat residue and sugarcane trash, respectively. A comparative study among crop residue removal (CRR), crop residue burning (CRB) and in situ decomposition of crop residues (IND) revealed that IND of rice and wheat residues took 30 days whereas IND of sugarcane trash took 45 days. The decomposition status was assessed by determining the initial and final lignin to cellulose ratio which increased significantly from 0.23 to 0.25, 0.21 to 0.23 and 0.24 to 0.27 for rice, wheat residues and sugarcane trash, respectively. No yield loss was noticed in IND for both rice-wheat system and sugarcane-based system; rather IND showed relatively better crop yield as well as soil health parameters than CRB and CRR. Furthermore, the environmental impact assessment of residue burning indicated a substantial loss of nutrients (28-31, 23-25 and 51-77 kg ha of N+PO+KO for rice, wheat and sugarcane residue) as well as the emission of pollutants to the atmosphere. However, more field trials, as well as refinement of the technology, are warranted to validate and establish the positive potential of in situ decomposition of crop residue to make it a successful solution against the crop residue burning.
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http://dx.doi.org/10.1007/s11356-021-12611-8DOI Listing
February 2021

Tolerance of cotton to elevated levels of Pb and its potential for phytoremediation.

Environ Sci Pollut Res Int 2021 Feb 23. Epub 2021 Feb 23.

ICAR-Indian Institute of Soil Science, Nabi Bagh, Berasia Road, Bhopal, India.

Two experiments were conducted to determine the cotton plant's tolerance to Pb and its remediation potential. In the first experiment, the phytoremediation potential was determined by exposing the plant to four levels of Pb (0, 500, 750, and 1000 mg kg). The cotton plant exhibited an excellent tolerance index at Pb 1000 mg kg (root 78.65% and shoot 93.08%) and lower grade of growth inhibition (root 21.35% and shoot 6.92%). Pb stress resulted in higher leakage of electrolytes and increased the synthesis of higher proline, total phenol, and free amino acid contents to mitigate stress. The plant could not meet the criteria of a hyperaccumulator of Pb. The concentration of Pb in the shoot was a mere 96 μg g dry wt (< the critical judging concentration of 1000 μg g dry wt), and bioconcentration and translocation factors were <1. The study established that cotton exhibited an exclusion mechanism of Pb. Further, the translocation efficiency (TE %) was very low, i.e., <50% (ranged from 49% at 500 mg kg to 42% at 1000 mg kg ), and the % of Pb removed by the crop was too little (on an average 0.1%). Pb inhibited the dehydrogenase activity (DHA) by 76%, fluorescein diacetate (FDA) hydrolysis by 60%, and β-glucosidase activity by 20%. However, applied Pb increased the population of actinomycetes by 3.21 times, but significantly decreased heterotrophic bacteria by 3.40 times and N fixers by over 53% over control. In the second experiment, the plant was exposed to very high Pb (0, 1000, 1500, 2000, 2500, and 3000 mg kg ) to determine the concentration up to which the plant will survive. The investigation revealed that plants could survive up to Pb 3000 mg kg. It confirmed the first experiment in the tolerance index, grade of growth inhibition, bioconcentration factor, translocation factor, and partitioning of Pb. Therefore, it was concluded that the cotton plant was an excluder of Pb and could be effectively cultivated for the phytostabilization of soils polluted with Pb.
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http://dx.doi.org/10.1007/s11356-021-13067-6DOI Listing
February 2021

Thermophilic ligno-cellulolytic fungi: The future of efficient and rapid bio-waste management.

J Environ Manage 2019 Aug 20;244:144-153. Epub 2019 May 20.

Former Member, Planning Commission, Government of India, New Delhi, 110001, India.

To accelerate the process of decomposition using consortia of thermophilic ligno-cellulolytic fungi, different crop residues viz. sorghum (SG), soybean (SS), maize (MS), sugarcane (SC), cotton (CS) and pigeon pea (PS) with a varied C:N ratio and sawdust (SD) having high lignin content were collected and used for decomposition process. Compost quality assessed by evaluating different maturity and stability indices at five succeeding stages [first mesophilic (M1), thermophilic (T), second mesophilic (M2), cooling (C) and humification (H)]. A significant reduction was observed in the C:N ratio, biodegradability index, nitrification index, ratio of water-soluble carbon to organic nitrogen (WSC/Org.N) with an increase in concomitant over time while Ash (%), organic matter loss (%), CEC/TOC ratio, cellulose biodegradation ratio (BR) and lignin/cellulose ratio were significantly increased with time. By correlation study, biodegradability index (BI) and fluorescein diacetate (FDA) hydrolysis emerged as the most suitable compost maturity and stability parameters, respectively. Principal component analysis (PCA) results confirmed that BI, BR, WSC/Org. N and FDA can be regarded as key indicators for assessing compost quality. Our findings conclude that fungal consortia of Tricoderma viride, Rhizomucor pusillus, Aspergillus awamori and Aspergillus flavus can accelerate decomposition time from 8 to 12 months (which is normal farming practice) to 120 days.
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http://dx.doi.org/10.1016/j.jenvman.2019.04.015DOI Listing
August 2019

D5 dopamine receptors are required for dopaminergic activation of phospholipase C.

Mol Pharmacol 2009 Mar 1;75(3):447-53. Epub 2008 Dec 1.

Department of Pharmaceutical Sciences, Laboratory of Integrative Neuropharmacology, Thomas Jefferson University School of Pharmacy, Philadelphia, PA 19107, USA.

Dopamine activates phospholipase C in discrete regions of the mammalian brain, and this action is believed to be mediated through a D(1)-like receptor. Although multiple lines of evidence exclude a role for the D(1) subtype of D(1)-like receptors in the phosphoinositide response, the D(5) subtype has not been similarly examined. Here, mice lacking D(5) dopamine receptors were tested for dopamine agonist-induced phosphoinositide signaling both in vitro and in vivo. The results show that hippocampal, cortical, and striatal tissues of D(5) receptor knockout mice significantly or completely lost the ability to produce inositol phosphate or diacylglycerol messengers after stimulation with dopamine or several selective D(1)-like receptor agonists. Moreover, endogenous inositol-1,4,5-trisphosphate stimulation by the phospholipase C-selective D(1)-like agonist 3-methyl-6-chloro-7,8-dihydroxy-1-[3methylphenyl]-2,3,4,5-tetrahydro-1H-3-benzazepine (SKF83959) was robust in wild-type animals but undetectable in the D(5) receptor mutants. Hence, D(5) receptors are required for dopamine and selective D(1)-like agonists to induce phospholipase C-mediated phosphoinositide signaling in the mammalian brain.
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http://dx.doi.org/10.1124/mol.108.053017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2684903PMC
March 2009
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