Publications by authors named "Garima Dubey"

8 Publications

  • Page 1 of 1

Ponder of concern and long-term safety of infants from mothers with chronic hepatitis B treated with tenofovir disoproxil.

Gut 2021 May 5. Epub 2021 May 5.

Department of Microbiology, All India Institute of Medical Science-Bhopal, Bhopal, Madhya Pradesh, India.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/gutjnl-2021-324967DOI Listing
May 2021

Do methanotrophs drive phosphorus mineralization in soil ecosystem?

Can J Microbiol 2021 Jun 10;67(6):464-475. Epub 2020 Dec 10.

Indian Institute of Soil Science, Indian Council of Agricultural Research, Berasia Road, Nabibagh, Bhopal 462038, India.

Experiments were carried out to elucidate linkage between methane consumption and mineralization of phosphorous (P) from different P sources. The treatments were () no CH + no P amendment (absolute control), () with CH + no P amendment (control), () with CH + inorganic P as Ca(PO), and () with CH + organic P as sodium phytate. P sources were added at 25 µg P·(g soil). Soils were incubated to undergo three repeated CH feeding cycles, referred to as feeding cycle I, feeding cycle II, and feeding cycle III. CH consumption rate (µg CH consumed·(g soil)·day) was 0.297 ± 0.028 in no P amendment control, 0.457 ± 0.016 in Ca(PO), and 0.627 ± 0.013 in sodium phytate. Rate was stimulated by 2 to 6 times over CH feeding cycles and followed the trend of sodium phytate > Ca(PO) > no P amendment control. CH consumption stimulated P solubilization from Ca(PO) by a factor of 2.86. Acid phosphatase (µg paranitrophenol released·(g soil)·h) was higher in sodium phytate than the no P amendment control. Abundance of 16S rRNA and genes increased with CH consumption rates. The results of the study suggested that CH consumption drives mineralization of unavailable inorganic and organic P sources in the soil ecosystem.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1139/cjm-2020-0254DOI Listing
June 2021

Nitrous oxide production from soybean and maize under the influence of weedicides and zero tillage conservation agriculture.

J Hazard Mater 2021 01 26;402:123572. Epub 2020 Jul 26.

ICAR Indian Institute of Soil Science, Nabibagh, Bhopal, 462038, India. Electronic address:

Current experiment envisages evaluating NO production from nitrification and denitrification under the influence of weedicides, cropping systems and conservation agriculture (CA). The weed control treatments were conventional hand weeding (no weedicide), pre emergence weedicide pendimethalin and post emergence weedicide imazethapyr for soybean, atrazine for maize. Experiment was laid out in randomized block design with three replicates. Soils were collected from different depths and incubated at different moisture holding capacity (MHC). NO production from nitrification varied from 2.77 to 6.04 ng NO g soil d and from denitrification varied from 0.05 to 1.34 ng NO g soil d. Potential nitrification rate (0.16-0.39 mM NO produced g soil d) was higher than potential denitrification rate (0.45-0.93 mM NO reduced g soil d). NO production, nitrification, denitrification, and microbial gene abundance were higher in maize than soybean. Both NO production and nitrification decreased (p < 0.05) with soil depth, while denitrification increased (p < 0.05) with soil depth. Abundance of eubacteria and ammonia oxidizing bacteria (AOB) were high (p < 0.01) at upper soil layer and declined with depth. Abundance of ammonia oxidizing archaea (AOA) increased (p < 0.05) with soil depth. Study concludes that intensive use of weedicides in CA may stimulate NO production.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jhazmat.2020.123572DOI Listing
January 2021

Nitrification Rates Are Affected by Biogenic Nitrate and Volatile Organic Compounds in Agricultural Soils.

Front Microbiol 2019 14;10:772. Epub 2019 May 14.

ICAR Indian Institute of Soil Science, Bhopal, India.

The processes regulating nitrification in soils are not entirely understood. Here we provide evidence that nitrification rates in soil may be affected by complexed nitrate molecules and microbial volatile organic compounds (mVOCs) produced during nitrification. Experiments were carried out to elucidate the overall nature of mVOCs and biogenic nitrates produced by nitrifiers, and their effects on nitrification and redox metabolism. Soils were incubated at three levels of biogenic nitrate. Soils containing biogenic nitrate were compared with soils containing inorganic fertilizer nitrate (KNO) in terms of redox metabolism potential. Repeated NH-N addition increased nitrification rates (mM NO produced g soil d) from 0.49 to 0.65. Soils with higher nitrification rates stimulated ( < 0.01) abundances of 16S rRNA genes by about eight times, genes of nitrifying bacteria by about 25 times, and genes of nitrifying archaea by about 15 times. Soils with biogenic nitrate and KNO were incubated under anoxic conditions to undergo anaerobic respiration. The maximum rates of different redox metabolisms (mM electron acceptors reduced g soil d) in soil containing biogenic nitrate followed as: NO reduction 4.01 ± 0.22, Fe reduction 5.37 ± 0.12, SO reduction 9.56 ± 0.16, and CH production (μg g soil) 0.46 ± 0.05. Biogenic nitrate inhibited denitrificaton 1.4 times more strongly compared to mineral KNO. Raman spectra indicated that aliphatic hydrocarbons increased in soil during nitrification, and these compounds probably bind to NO to form biogenic nitrate. The mVOCs produced by nitrifiers enhanced ( < 0.05) nitrification rates and abundances of nitrifying bacteria. Experiments suggest that biogenic nitrate and mVOCs affect nitrification and redox metabolism in soil.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2019.00772DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6527594PMC
May 2019

Interactive effect of climate factors, biochar and insecticide chlorpyrifos on methane consumption and microbial abundance in a tropical Vertisol.

Ecotoxicol Environ Saf 2018 Aug 11;157:409-416. Epub 2018 Apr 11.

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

Climate change may increase the pest infestation leading to intensive use of insecticides. However, the effect of insecticide and climate factors on soil methane (CH) consumption is less understood. A laboratory experiment was carried out to evaluate the effect of temperature (15 °C, 35 °C, and 45 °C), moisture holding capacity (MHC) (60%, 100%), biochar (0%, 1%) and chlorpyrifos (0 ppm, 10 ppm) on CH consumption and microbial abundance in a tropical Vertisol of central India. Methane consumption rate k (ng CH consumed g soil d) varied from 0.065 ± 0.005 to 0.608 ± 0.018. Lowest k was in 15 °C-60% moisture holding capacity (MHC)-no biochar and with 10 ppm chlorpyrifos. Highest k was in 35 °C-100% MHC-1% biochar and without (0 ppm) chlorpyrifos. Cumulative CO production (ng CO produced g soil d) varied from 446 ± 15 to 1989 ± 116. Both CH consumption and CO production peaked in the treatment of 35 °C-100% MHC-1% biochar. Chlorpyrifos inhibited CH consumption irrespective of treatments. Abundance of 16S rRNA of eubacteria (× 10 g soil) varied from 2.33 ± 0.58 to 85.67 ± 7.00. Abundance of 16S rRNA genes representing Actinomycetes (× 10 g soil) varied from 7.67 ± 1.53 and pmoA gene (Methanotrophs) (× 10 g soil) varied from 1.23 ± 0.59 to 34.33 ± 6.51. Chlorpyrifos inhibited abundance of heterotrophic bacteria and methanotrophs but stimulated actinomycetes. Biochar stimulated the CH consumption, CO production and microbial abundance. Study highlighted that use of chlorpyrifos under climate change factors may inhibit CH consumption but the use of biochar may alleviate the negative effect of the chlorpyrifos.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ecoenv.2018.03.092DOI Listing
August 2018

Phylloplane bacteria of Jatropha curcas: diversity, metabolic characteristics, and growth-promoting attributes towards vigor of maize seedling.

Can J Microbiol 2017 Oct 31;63(10):822-833. Epub 2017 Jul 31.

Indian Institute of Soil Science, Nabibagh, Bhopal 462038, India.

The complex role of phylloplane microorganisms is less understood than that of rhizospheric microorganisms in lieu of their pivotal role in plant's sustainability. This experiment aims to study the diversity of the culturable phylloplane bacteria of Jatropha curcas and evaluate their growth-promoting activities towards maize seedling vigor. Heterotrophic bacteria were isolated from the phylloplane of J. curcas and their 16S rRNA genes were sequenced. Sequences of the 16S rRNA gene were very similar to those of species belonging to the classes Bacillales (50%), Gammaproteobacteria (21.8%), Betaproteobacteria (15.6%), and Alphaproteobacteria (12.5%). The phylloplane bacteria preferred to utilize alcohol rather than monosaccharides and polysaccharides as a carbon source. Isolates exhibited ACC (1-aminocyclopropane-1-carboxylic acid) deaminase, phosphatase, potassium solubilization, and indole acetic acid (IAA) production activities. The phosphate-solubilizing capacity (mg of PO solubilized by 10 cells) varied from 0.04 to 0.21. The IAA production potential (μg IAA produced by 10 cells in 48 h) of the isolates varied from 0.41 to 9.29. Inoculation of the isolates to maize seed significantly increased shoot and root lengths of maize seedlings. A linear regression model of the plant-growth-promoting activities significantly correlated (p < 0.01) with the growth parameters. Similarly, a correspondence analysis categorized ACC deaminase and IAA production as the major factors contributing 41% and 13.8% variation, respectively, to the growth of maize seedlings.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1139/cjm-2017-0189DOI Listing
October 2017

Novel Reassortant Highly Pathogenic Avian Influenza (H5N8) Virus in Zoos, India.

Emerg Infect Dis 2017 04 15;23(4):717-719. Epub 2017 Apr 15.

Highly pathogenic avian influenza (H5N8) viruses were detected in waterfowl at 2 zoos in India in October 2016. Both viruses were different 7:1 reassortants of H5N8 viruses isolated in May 2016 from wild birds in the Russian Federation and China, suggesting virus spread during southward winter migration of birds.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3201/eid2304.161886DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5367432PMC
April 2017

Diversity of bacteria and archaea in the rhizosphere of bioenergy crop Jatropha curcas.

3 Biotech 2016 Dec 2;6(2):257. Epub 2016 Dec 2.

Indian Institute of Soil Science, Nabibagh, Bhopal, 462038, India.

Plant-microbial interaction in rhizosphere plays vital role in shaping plant's growth and ecosystem function. Most of the rhizospheric microbial diversity studies are restricted to bacteria. In natural ecosystem, archaea also constitutes a major component of the microbial population. However, their diversity is less known compared to bacteria. Experiments were carried out to examine diversity of bacteria and archaea in the rhizosphere of bioenergy crop Jatropha curcas (J. curcas). Samples were collected from three locations varying widely in the soil physico-chemical properties. Diversity was estimated by terminal restriction fragment length polymorphism (TRFLP) targeting 16S rRNA gene of bacteria and archaea. Fifteen bacterial and 17 archaeal terminal restriction fragments (TRFs) were retrieved from J. curcas rhizosphere. Bacterial indicative TRFs were Actinobacteria, Firmicutes, Acidobacteria, Verrumicrobiaceae, and Chlroflexi. Major archaeal TRFs were crenarchaeota, and euryarchaeota. In case of bacteria, relative fluorescence was low for TRF160 and high for TRF51, TRF 420. Similarly, for archaea relative fluorescence of TRF 218, and TRF 282 was low and high for TRF 278, TRF468 and TRF93. Principal component analysis (PCA) of bacterial TRFs designated PC 1 with 46.83% of variation and PC2 with 31.07% variation. Archaeal TRFs designated 90.94% of variation by PC1 and 9.05% by PC2. Simpson index varied from 0.530 to 0.880 and Shannon index from 1.462 to 3.139 for bacteria. For archaea, Simpson index varied from 0.855 to 0.897 and Shannon index varied from 3.027 to 3.155. Study concluded that rhizosphere of J. curcas constituted of diverse set of both bacteria and archaea, which might have promising plant growth promoting activities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s13205-016-0546-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5135702PMC
December 2016
-->