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1.
J Food Sci Technol ; 60(7): 2001-2011, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37206425

ABSTRACT

Microfiltration of citrus fruit juices using membrane technology is a promising method for clarification without losing their inherent properties to extend their shelf life. The present work discusses the development of a tubular ceramic microfiltration membrane and its performance in clarifying two kinds of citrus fruit juices, mandarin and sweet orange. The membrane was prepared by the extrusion method from indigenous bentonite clay, exhibited a porosity of 37% with 0.11 µm pore size, and possessed adequate flexural strength of 18 MPa. The fabricated membrane's potential was evaluated by conducting the tangential filtration of both centrifuged and enzyme-treated centrifuged fruit juices. Also, the applied pressure (68.94-344.7 kPa) and crossflow rate (110-150 Lph) were varied to study the clarified juice properties. At low operating conditions, the highest clarity of the juices was identified despite low permeate flux. The desired properties of juices, including pH, citric acid content, and total soluble solids, were unaffected by pretreatment and tangential membrane filtration, whereas the pectin content, which reduces the juice quality, was eliminated entirely. Furthermore, fouling analysis was carried out using Hermia's models, and cake filtration was identified to be dominant for both juices. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05734-y.

2.
Proc Biol Sci ; 287(1936): 20201846, 2020 10 14.
Article in English | MEDLINE | ID: mdl-33049166

ABSTRACT

The genome of the plant-infecting viruses in the family Geminiviridae is composed of one or two circular single stranded DNA of approximately 2.7-5.2 kb in length. These viruses have emerged as the most devastating pathogen infecting a large number of crops and weeds across the continents. They code for fewer open reading frames (ORFs) through the generation of overlapping transcripts derived from the bidirectional viral promoters. Members of geminiviruses code for up to four ORFs in the virion-sense strand, and their gene expression is regulated by various cis-elements located at their promoters in the intergenic region. These viral proteins perform multiple functions at every stage of the viral life cycle such as virus transport, insect-mediated virus transmission and suppression of host defence. They impede the host's multi-layered antiviral mechanisms including gene silencing (at transcriptional and post-transcriptional levels) and hypersensitive response. This review summarizes the essential role of virion-sense strand encoded proteins in transport of viral genomes within and between plant cells, countering defence in hosts (both plants and the insects), and also in the ubiquitous role in vector-mediated transmission. We highlight the significance of their pro-viral activities in manipulating host-derived innate immune responses and the interaction with whitefly-derived proteins. We also discuss the current knowledge on virus replication and transcription within the insect body.


Subject(s)
Insect Vectors/virology , Plant Viruses/genetics , Plants/virology , Animals , Hemiptera/virology , Viral Proteins
3.
Arch Virol ; 165(9): 2099-2103, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32556597

ABSTRACT

Geminiviruses cause considerable yield loss in several crop plants worldwide. In 2016, several hollyhock plants displaying yellow mosaic and leaf curling symptoms were noticed in a nursery of Jawaharlal Nehru University, New Delhi, India. Analysis of the collected samples indicated an association of monopartite and bipartite begomoviruses with satellites. Three begomoviruses (including a member of a new begomovirus species), two alphasatellites, and a betasatellite were isolated from yellow-mosaic-disease-affected plants. Similarly, a begomovirus, two alphasatellites, and a betasatellite were found to be associated with leaf curl disease of hollyhock. These begomoviruses and satellites were found to be recombinants. By harboring diverse begomoviruses and satellite DNAs, hollyhock may serve as a potential source of virus inoculum.


Subject(s)
Begomovirus/isolation & purification , Malvaceae/virology , Plant Diseases/virology , Satellite Viruses/isolation & purification , Begomovirus/classification , Begomovirus/genetics , Begomovirus/physiology , India , Phylogeny , Satellite Viruses/classification , Satellite Viruses/genetics , Satellite Viruses/physiology
4.
Mol Plant Pathol ; 20(7): 1019-1033, 2019 07.
Article in English | MEDLINE | ID: mdl-31210029

ABSTRACT

Begomoviruses have emerged as a group of plant pathogens that cause devastating diseases in a wide range of crops in tropical and subtropical regions of the world. Betasatellites, the circular single-stranded DNA molecules with the size of almost half of that of the associated helper begomoviruses, are often essential for the production of typical disease symptoms in several virus-host systems. Association of betasatellites with begomoviruses results in more severe symptoms in the plants and affects the yield of numerous crops leading to huge agroeconomic losses. ßC1, the only protein encoded by betasatellites, plays a multifaceted role in the successful establishment of infection. This protein counteracts the innate defence mechanisms of the host, like RNA silencing, ubiquitin-proteasome system and defence responsive hormones. In the last two decades, the molecular aspect of betasatellite pathogenesis has attracted much attention from the researchers worldwide, and reports have shown that ßC1 protein aggravates the helper begomovirus disease complex by modulating specific host factors. This review discusses the molecular aspects of the pathogenesis of betasatellites, including various ßC1-host factor interactions and their effects on the suppression of defence responses of the plants.


Subject(s)
DNA, Satellite/genetics , Geminiviridae/pathogenicity , Geminiviridae/genetics , Genetic Variation , Plant Diseases/immunology , Plant Diseases/virology , Plants/immunology , Plants/virology , Virus Replication/genetics
6.
J Exp Bot ; 69(8): 2085-2102, 2018 04 09.
Article in English | MEDLINE | ID: mdl-29432546

ABSTRACT

RNA silencing is an integral part of the cellular defense mechanisms in plants that act against virus infection. However, the specific role of RNA silencing and the interplay between host and virus components during recovery from geminivirus infection remains unknown. Hence, in this study we aimed to examine the mechanism behind the host-specific recovery of Nicotiana tabacum infected with Tomato leaf curl Gujarat virus (ToLCGV). Unlike Tomato leaf curl New Delhi virus (ToLCNDV), ToLCGV infection resulted in symptom remission in N. tabacum, and we found that this was mainly due to cross-talk between the pre-coat protein (encoded by the AV2 ORF) of the virus and the host RNA-silencing component RNA-dependent RNA polymerase 1 (encoded by NtRDR1) of N. tabacum. Moreover, apart from the AV2 mutant, other mutants of ToLCNDV developed severe symptoms on a transgenic NtRDR1-overexpression line of N. benthamiana. In contrast, inoculation with ToLCGV resulted in symptom remission, which was due to enhanced methylation of the ToLCGV promoter. Our study reveals a novel 'arms race' in which the pre-coat protein of ToLCNDV selectively blocks the recovery process through inhibiting host-specific RDR1-mediated antiviral silencing in tobacco.


Subject(s)
Capsid Proteins/metabolism , Geminiviridae/metabolism , Nicotiana/enzymology , Plant Diseases/virology , Plant Proteins/metabolism , RNA-Dependent RNA Polymerase/metabolism , Begomovirus/physiology , Capsid Proteins/genetics , Geminiviridae/genetics , Host-Pathogen Interactions , Plant Diseases/genetics , Plant Proteins/genetics , RNA Interference , RNA-Dependent RNA Polymerase/genetics , Nicotiana/genetics , Nicotiana/virology
8.
Prep Biochem Biotechnol ; 47(7): 687-698, 2017 Aug 09.
Article in English | MEDLINE | ID: mdl-28277946

ABSTRACT

In this study, Faujasite (FAU) zeolite was coated on low-cost tubular ceramic support as a separating layer through hydrothermal route. The mixture of silicate and aluminate solutions was used to create a zeolitic separation layer on the support. The prepared zeolite ceramic composite membrane was characterized using X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), particle size distribution (PSD), field emission scanning electron microscopy (FESEM), and zeta potential measurements. The porosity of ceramic support (53%) was reduced by the deposition of FAU (43%) zeolite layer. The pore size and water permeability of the membrane were evaluated as 0.179 µm and 1.62 × 10-7 m3/m2 s kPa, respectively, which are lower than that of the support (pore size of 0.309 µm and water permeability of 5.93 × 10-7 m3/m2 s kPa). The permeate flux and rejection potential of the prepared membrane were evaluated by microfiltration of bovine serum albumin (BSA). To study the influences of three independent variables such as operating pressure (68.94-275.79 kPa), concentration of BSA (100-500 ppm), and solution pH (2-4) on permeate flux and percentage of rejection, the response surface methodology (RSM) was used. The predicted models for permeate flux and rejection were further subjected to biobjective genetic algorithm (GA). The hybrid RSM-GA approach resulted in a maximum permeate flux of 2.66 × 10-5 m3/m2 s and BSA rejection of 88.02%, at which the optimum conditions were attained as 100 ppm BSA concentration, 2 pH solution, and 275.79 kPa applied pressure. In addition, the separation efficiency was compared with other membranes applied for BSA separation to know the potential of the fabricated FAU zeolite ceramic composite membrane.


Subject(s)
Filtration/instrumentation , Membranes, Artificial , Serum Albumin, Bovine/isolation & purification , Zeolites/chemistry , Algorithms , Animals , Cattle , Permeability , Porosity , Pressure , Water/chemistry , X-Ray Diffraction
9.
Infect Genet Evol ; 49: 39-47, 2017 04.
Article in English | MEDLINE | ID: mdl-28062387

ABSTRACT

The genus, begomovirus (family Geminiviridae) includes a large number of viruses infecting a wide range of plant species worldwide. The majority of monopartite begomoviruses are associated with satellites (betasatellites) and/or satellite-like molecules (alphasatellites). In spite of the Indo-China region being regarded as the centre of origin of begomoviruses and satellites, a detailed study on the emergence and evolution of alphasatellites in India has not yet conducted. Our present analysis indicated the association of 22 alphasatellites with monopartite and bipartite begomovirus-betasatellite complexes in India. Based on sequence pairwise identity, these alphasatellites were categorized into five distinct groups: Cotton leaf curl alphasatellite, Gossypium darwinii symptomless alphasatellite, Gossypium mustelinum symptomless alphasatellite, Okra leaf curl alphasatellite and an unreported Chilli leaf curl alphasatellite (ChiLCA). Furthermore, infectivity analysis of the cloned ChiLCA along with the viral components of either cognate or non-cognate chilli-infecting begomoviruses on Nicotiana benthamiana suggested that ChiLCA is dispensable for leaf curl disease development. It is noteworthy that in the presence of ChiLCA, a marginal decrease in betasatellite DNA level was noticed. Additionally, high genetic variability and diverse recombination patterns were detected among these alphasatellites, and the nucleotide substitution rate for the Rep gene of ChiLCA was determined to be 2.25×10-3nucleotides/site/year. This study highlights the genetic distribution, and likely contribution of recombination and nucleotide diversity in facilitating the emergence of alphasatellites.


Subject(s)
Begomovirus/genetics , DNA, Satellite/genetics , DNA, Viral/genetics , Genetic Variation , Phylogeny , Recombination, Genetic , Abelmoschus/virology , Begomovirus/classification , Capsicum/virology , Gossypium/virology , India , Plant Diseases/virology , Plant Leaves/virology , Sequence Analysis, DNA , Nicotiana/virology
10.
Neurochem Res ; 41(5): 951-7, 2016 May.
Article in English | MEDLINE | ID: mdl-26738987

ABSTRACT

Microglia activation plays an important role in neuroinflammation and contributes to several neurological disorders. Hence, inhibition of both microglia activation and pro-inflammatory cytokines may lead to the effective treatment of neurodegenerative diseases. In this study, we found that GRh2 inhibited the inflammatory response to lipopolysaccharide (LPS) and prevented the LPS-induced neurotoxicity in microglia cells. GRh2 significantly decreased the generation of nitric oxide production, and tumor necrosis factor-α, interleukin (IL)-6, IL-1ß, cyclooxygenase-2 and inducible nitric oxide synthase in LPS-induced activated microglia cells. Furthermore, GRh2 (20 and 50 µM) significantly increased TGF-ß1 expression and reduced the expression of Smad. These results suggest that GRh2 effectively inhibits microglia activation and production of pro-inflammatory cytokines via modulating the TGF-ß1/Smad pathway.


Subject(s)
Ginsenosides/pharmacology , Inflammation Mediators/metabolism , Lipopolysaccharides/pharmacology , Microglia/drug effects , Neuroprotective Agents/pharmacology , Smad Proteins/metabolism , Transforming Growth Factor beta1/metabolism , Animals , Cell Line , Cyclooxygenase 2/biosynthesis , Interleukin-1beta/biosynthesis , Interleukin-6/biosynthesis , Mice , Microglia/metabolism , Nitric Oxide/biosynthesis , Nitric Oxide Synthase/biosynthesis , Signal Transduction , Tumor Necrosis Factor-alpha/biosynthesis
12.
Environ Toxicol Pharmacol ; 37(1): 174-84, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24355798

ABSTRACT

The present study was aimed to investigate the chemopreventive potential of troxerutin on 1,2-dimethylhydrazine (DMH) induced rat colon carcinogenesis by evaluating the antioxidant and lipid peroxidation (LPO) status. Rats were randomly divided into six groups. Group I rats served as control. Group II rats received troxerutin (50 mg/kgb.w., p.o.) for 16 weeks. Groups III-VI rats received subcutaneous injections of DMH (20 mg/kgb.w., s.c.) once a week, for the first 4 weeks. In addition to DMH, groups IV-VI rats received troxerutin at the doses of 12.5, 25 and 50 mg/kgb.w., respectively. In DMH treated rats, our results showed decreased activities of antioxidants and increased levels of LPO in the liver. Moreover, LPO and antioxidants in the colon were found to be significantly diminished in DMH the treated rats. Furthermore, enhanced activity of colonic vitamin C and vitamin E levels were observed in DMH alone treated rats (group III), which was significantly reversed on troxerutin supplementation. Troxerutin at the dose of 25 mg/kgb.w. had shown profound beneficial effects by exhibiting near normal biochemical profile and well-preserved colon histology as compared to the other two tested doses (12.5 and 50 mg/kgb.w.). These findings suggest that troxerutin could serve as a novel agent for colon cancer chemoprevention.


Subject(s)
Antineoplastic Agents/pharmacology , Colonic Neoplasms/metabolism , Hydroxyethylrutoside/analogs & derivatives , 1,2-Dimethylhydrazine , Administration, Oral , Animals , Ascorbic Acid/metabolism , Carcinogens , Catalase/metabolism , Colon/drug effects , Colon/metabolism , Colon/pathology , Colonic Neoplasms/chemically induced , Colonic Neoplasms/pathology , Glutathione/metabolism , Hydroxyethylrutoside/pharmacology , Lipid Peroxidation/drug effects , Liver/drug effects , Liver/metabolism , Male , Rats , Rats, Wistar , Superoxide Dismutase/metabolism , Vitamin E/metabolism
13.
Curr Microbiol ; 65(1): 44-53, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22526571

ABSTRACT

Urinary tract infection (UTI) is among the most common bacterial infections and poses a significant healthcare burden. Escherichia coli is the most common cause of UTI accounting for up to 70 % and a variable contribution from Proteus mirabilis, Pseudomonas aeruginosa and Klebsiella pneumoniae. To establish a complete diagnostic system, we have developed a single-tube multiplex PCR assay (mPCR) for the detection of the above-mentioned four major uropathogens. The sensitivity of the assay was found to be as low as 10(2) cfu/ml of cells. The mPCR evaluated on 280 clinical isolates detected 100 % of E. coli, P. aeruginosa, P. mirabilis and 95 % of K. pneumonia. The assay was performed on 50 urine samples and found to be specific and sensitive for clinical diagnosis. In addition, the mPCR was also validated on spiked urine samples using 40 clinical isolates to demonstrate its application under different strain used in this assay. In total, mPCR reported here is a rapid and simple screening tool that can compete with conventional biochemical-based screening assays that may require 2-3 days for detection.


Subject(s)
Bacteria/isolation & purification , Bacterial Infections/microbiology , Multiplex Polymerase Chain Reaction/methods , Urinary Tract Infections/microbiology , Bacteria/classification , Bacteria/genetics , Bacterial Infections/diagnosis , Humans , Sensitivity and Specificity , Urinary Tract Infections/diagnosis
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