In developing countries like India, ruminants fed with lignocellulosic feed. It contains cellulos... more In developing countries like India, ruminants fed with lignocellulosic feed. It contains cellulose, hemicelluloses and lignin. Ruminants can utilize these particles with the help of microbial population present in rumen. Among these, bacterial population play key role in feed digestion. The fibrolytic bacteria degrades insoluble fiber into soluble sugars and non fibrolytic bacteria associates with them converts soluble sugars into metabolic products, thereby helps to control feedback inhibition of fiber degrading bacteria. Hence, it is important to understand the association between fiber and non fiber degrading bacteria. In this review, we discussed about predominant fiber degrading and non fiber degrading bacterial species and their association.
The degradation of fiber by microbiota is an important and unique process occurring in ruminants.... more The degradation of fiber by microbiota is an important and unique process occurring in ruminants. The fibrolytic bacterial consortia, primarily Fibrobacter succinogenes and Ruminococcus species, have different strategies for fiber degradation. It is very important to understand the enzymes and encoding genes of cellulolytic bacteria and the mechanism of cellulosome, a significant integral part of the fibrolysis. In this chapter, we discuss cellulolytic strategies, followed by rumen bacterial populations, molecular identification, and omics application in substrate degradation mechanism exploitation.
Pakistan journal of biological sciences : PJBS, 2017
A widely used pesticide quinalphos (O, O-diethyl O-quinoxalin-2-yl phosphorothioate) may be an un... more A widely used pesticide quinalphos (O, O-diethyl O-quinoxalin-2-yl phosphorothioate) may be an undesirable and persistent pollutant to non-target environments like rivers and other ecosystems. The objective of this study was to isolate a potential degradant bacterium of quinalphos from polluted soils and test its fitness under various culture conditions. A soil bacterium strain, capable of utilizing quinalphos as its sole source of carbon and energy was isolated from soil by enrichment method on a minimal salts medium (MSM). On the basis of morphological, biochemical and 16S rRNA gene sequence analysis the bacterium is a species of the genus Bacillus and it was closely related to Bacillus subtilis. Quinalphos degrading capabilities of this bacterium were assessed under different culture conditions. Quinalphos degradation data were analysed byusing a two-way ANOVA analysis with the Statistica v.10. Bacillus subtilis grew on quinalphos with a generation time of 32.34 min or 0.54 h in ...
The degradation of a widely used organophosphorus insecticide, monocrotophos (dimethyl (E)-1-meth... more The degradation of a widely used organophosphorus insecticide, monocrotophos (dimethyl (E)-1-methyl-2-methylcarbamoyl vinyl phosphate) in two Indian agricultural soils at two concentration levels, 10 and 100 microg g(-1) soil under aerobic conditions at 60% water-holding capacity at 28+/-4 degrees C was studied in a laboratory. The degradation of monocrotophos at both concentrations in black vertisol and red alfinsol soils was rapid accounting for 96-98% of the applied quantity and followed the first-order kinetics with rate constants (k) of 0.0753 and 0.0606 day(-1) and half-lives (t1/2) of 9.2 and 11.4 days, respectively. Degradation of monocrotophos in soils proceeded by hydrolysis with formation of N-methylacetoacetamide. Even three additions of monocrotophos at 10 microg g(-1) soil did not result in its enhanced degradation. However, there was cumulative accumulation of N-methylacetoacetamide in soils pretreated with monocrotophos to the tune of 7-15 microg g(-1) soil. Both bio...
Bacteria belonging to the genusAcinetobacterare ubiquitous in soil and water. Only a few species,... more Bacteria belonging to the genusAcinetobacterare ubiquitous in soil and water. Only a few species, includingAcinetobacter baumannii, and the unnamedAcinetobactergenomic species (gen. sp.) 3 and 13TU, which together with the soil organismAcinetobacter calcoaceticusare combined in theA. calcoaceticus–A. baumannii(Acb) complex, have been recognized as important nosocomial infectious agents. The ecology, epidemiology and pathology of most species are not yet well established. Lack of practical and accurate methods limits routine identification of clinical isolates and thus hampers precise identification of those of the Acb complex and otherAcinetobacterspecies of possible clinical significance. We previously identified a 350 bp highly variable zone on therpoBgene which appeared to be a promising target for rapid molecular identification. In the present study, we validated this method for accuracy on a collection of reference strains belonging toA. calcoaceticus(5 strains),Acinetobacterge...
Journal of Environmental Science and Health, Part B, 2005
High infestations of alexandergrass (Brachiaria plantaginea) in experimental area have reduced se... more High infestations of alexandergrass (Brachiaria plantaginea) in experimental area have reduced seedbank of some weed species in soil at a greater degree compared to those obtained with the use of an efficient herbicide. Aconitic acid (AA) has been identified in those plants in high concentration. Thus, two experiments were carried out in the laboratory to determine the effects of pure AA on weed seed germination and on endophytic fungi in wild poinsettia (Euphorbia heterophylla) and morningglory (Ipomoea grandifolia) weed species. Doses of AA (0, 0.5, 1.0, and 2.0 mM) were introduced in agar-water 0.5% medium and weed seeds treated with and without external sterilization by sodium hypochloride. Four replications of fifty seeds of each species by treatment were sown in plastic boxes with cover and maintained in germination chamber for 12 days. Reduction in germination rate, root and stem growth were observed in both species, as well as reduction in root number in morningglory were also observed at 2.0 mM concentration of AA. An increase in number of seeds with presence of endophytic fungi was also observed in both species, independently of seed sterilization, mainly of a green type fungi coloration in wild poinsettia. Aconitic acid presents allelopathic activity and can stimulate endophytic fungi species growth in weed seeds.
Thirty-three isolates of Bartonella spp., including 11 isolates not belonging to previously known... more Thirty-three isolates of Bartonella spp., including 11 isolates not belonging to previously known species, were isolated from 66 Rattus norvegicus subjects trapped in the city of Marseille, France. Based on seven different gene sequences, the 11 isolates were assigned to Bartonella rattimassiliensis sp. nov. and Bartonella phoceensis sp. nov.
Acinetobacter species are defined on the basis of several phenotypic characters, results of DNA-D... more Acinetobacter species are defined on the basis of several phenotypic characters, results of DNA-DNA homology, and more recently, similarities or dissimilarities in 16S rRNA gene sequences. However, the 16S rRNA gene is not polymorphic enough to clearly distinguish all Acinetobacter species. We used an RNA polymerase β-subunit gene ( rpoB )-based identification scheme for the delineation of species within the genus Acinetobacter , and towards that end, we determined the complete rpoB gene and flanking spacer ( rplL - rpoB and rpoB - rpoC ) sequences of the 17 reference strains of Acinetobacter species and 7 unnamed genomospecies. By using complete gene sequences (4,089 bp), we clearly separated all species and grouped them into different clusters. A phylogenetic tree constructed using these sequences was supported by bootstrap values higher than those obtained with 16S rRNA or the gyrB or recA gene. Four pairs of primers enabled us to amplify and sequence two highly polymorphic parti...
Interaction effects of the insecticides monocrotophos and quinalphos (organophosphates), and cype... more Interaction effects of the insecticides monocrotophos and quinalphos (organophosphates), and cypermethrin (pyrethroid), on microbial activities in two agricultural soils-black vertisol soil and red alfinsol soil were tested for 30 days under laboratory conditions. Individual application of the three insecticides at 5, 10 and 25microg g(-1) to the soil distinctly enhanced the activities of cellulase and amylase. Insecticide combinations involving monocrotophos or quinalphos with cypermethrin yielded synergistic, antagonistic and additive interaction effects on both enzymes in the soils. At lower levels, 5 and 10microg g(-1), the insecticides in combination interacted additively or synergistically toward both enzymes. But, both combinations at the highest level of 25microg g(-1) exhibited an antagonistic interaction, with a reduction in enzyme activities to a level lower than that of the control. Interaction effects of insecticides in combinations on two enzyme activities in both soils were related to populations of cellulolytic and amylolytic organisms in soils under the impact of combination of insecticides. These interaction responses were persistent even for 30 days.
In developing countries like India, ruminants fed with lignocellulosic feed. It contains cellulos... more In developing countries like India, ruminants fed with lignocellulosic feed. It contains cellulose, hemicelluloses and lignin. Ruminants can utilize these particles with the help of microbial population present in rumen. Among these, bacterial population play key role in feed digestion. The fibrolytic bacteria degrades insoluble fiber into soluble sugars and non fibrolytic bacteria associates with them converts soluble sugars into metabolic products, thereby helps to control feedback inhibition of fiber degrading bacteria. Hence, it is important to understand the association between fiber and non fiber degrading bacteria. In this review, we discussed about predominant fiber degrading and non fiber degrading bacterial species and their association.
The degradation of fiber by microbiota is an important and unique process occurring in ruminants.... more The degradation of fiber by microbiota is an important and unique process occurring in ruminants. The fibrolytic bacterial consortia, primarily Fibrobacter succinogenes and Ruminococcus species, have different strategies for fiber degradation. It is very important to understand the enzymes and encoding genes of cellulolytic bacteria and the mechanism of cellulosome, a significant integral part of the fibrolysis. In this chapter, we discuss cellulolytic strategies, followed by rumen bacterial populations, molecular identification, and omics application in substrate degradation mechanism exploitation.
Pakistan journal of biological sciences : PJBS, 2017
A widely used pesticide quinalphos (O, O-diethyl O-quinoxalin-2-yl phosphorothioate) may be an un... more A widely used pesticide quinalphos (O, O-diethyl O-quinoxalin-2-yl phosphorothioate) may be an undesirable and persistent pollutant to non-target environments like rivers and other ecosystems. The objective of this study was to isolate a potential degradant bacterium of quinalphos from polluted soils and test its fitness under various culture conditions. A soil bacterium strain, capable of utilizing quinalphos as its sole source of carbon and energy was isolated from soil by enrichment method on a minimal salts medium (MSM). On the basis of morphological, biochemical and 16S rRNA gene sequence analysis the bacterium is a species of the genus Bacillus and it was closely related to Bacillus subtilis. Quinalphos degrading capabilities of this bacterium were assessed under different culture conditions. Quinalphos degradation data were analysed byusing a two-way ANOVA analysis with the Statistica v.10. Bacillus subtilis grew on quinalphos with a generation time of 32.34 min or 0.54 h in ...
The degradation of a widely used organophosphorus insecticide, monocrotophos (dimethyl (E)-1-meth... more The degradation of a widely used organophosphorus insecticide, monocrotophos (dimethyl (E)-1-methyl-2-methylcarbamoyl vinyl phosphate) in two Indian agricultural soils at two concentration levels, 10 and 100 microg g(-1) soil under aerobic conditions at 60% water-holding capacity at 28+/-4 degrees C was studied in a laboratory. The degradation of monocrotophos at both concentrations in black vertisol and red alfinsol soils was rapid accounting for 96-98% of the applied quantity and followed the first-order kinetics with rate constants (k) of 0.0753 and 0.0606 day(-1) and half-lives (t1/2) of 9.2 and 11.4 days, respectively. Degradation of monocrotophos in soils proceeded by hydrolysis with formation of N-methylacetoacetamide. Even three additions of monocrotophos at 10 microg g(-1) soil did not result in its enhanced degradation. However, there was cumulative accumulation of N-methylacetoacetamide in soils pretreated with monocrotophos to the tune of 7-15 microg g(-1) soil. Both bio...
Bacteria belonging to the genusAcinetobacterare ubiquitous in soil and water. Only a few species,... more Bacteria belonging to the genusAcinetobacterare ubiquitous in soil and water. Only a few species, includingAcinetobacter baumannii, and the unnamedAcinetobactergenomic species (gen. sp.) 3 and 13TU, which together with the soil organismAcinetobacter calcoaceticusare combined in theA. calcoaceticus–A. baumannii(Acb) complex, have been recognized as important nosocomial infectious agents. The ecology, epidemiology and pathology of most species are not yet well established. Lack of practical and accurate methods limits routine identification of clinical isolates and thus hampers precise identification of those of the Acb complex and otherAcinetobacterspecies of possible clinical significance. We previously identified a 350 bp highly variable zone on therpoBgene which appeared to be a promising target for rapid molecular identification. In the present study, we validated this method for accuracy on a collection of reference strains belonging toA. calcoaceticus(5 strains),Acinetobacterge...
Journal of Environmental Science and Health, Part B, 2005
High infestations of alexandergrass (Brachiaria plantaginea) in experimental area have reduced se... more High infestations of alexandergrass (Brachiaria plantaginea) in experimental area have reduced seedbank of some weed species in soil at a greater degree compared to those obtained with the use of an efficient herbicide. Aconitic acid (AA) has been identified in those plants in high concentration. Thus, two experiments were carried out in the laboratory to determine the effects of pure AA on weed seed germination and on endophytic fungi in wild poinsettia (Euphorbia heterophylla) and morningglory (Ipomoea grandifolia) weed species. Doses of AA (0, 0.5, 1.0, and 2.0 mM) were introduced in agar-water 0.5% medium and weed seeds treated with and without external sterilization by sodium hypochloride. Four replications of fifty seeds of each species by treatment were sown in plastic boxes with cover and maintained in germination chamber for 12 days. Reduction in germination rate, root and stem growth were observed in both species, as well as reduction in root number in morningglory were also observed at 2.0 mM concentration of AA. An increase in number of seeds with presence of endophytic fungi was also observed in both species, independently of seed sterilization, mainly of a green type fungi coloration in wild poinsettia. Aconitic acid presents allelopathic activity and can stimulate endophytic fungi species growth in weed seeds.
Thirty-three isolates of Bartonella spp., including 11 isolates not belonging to previously known... more Thirty-three isolates of Bartonella spp., including 11 isolates not belonging to previously known species, were isolated from 66 Rattus norvegicus subjects trapped in the city of Marseille, France. Based on seven different gene sequences, the 11 isolates were assigned to Bartonella rattimassiliensis sp. nov. and Bartonella phoceensis sp. nov.
Acinetobacter species are defined on the basis of several phenotypic characters, results of DNA-D... more Acinetobacter species are defined on the basis of several phenotypic characters, results of DNA-DNA homology, and more recently, similarities or dissimilarities in 16S rRNA gene sequences. However, the 16S rRNA gene is not polymorphic enough to clearly distinguish all Acinetobacter species. We used an RNA polymerase β-subunit gene ( rpoB )-based identification scheme for the delineation of species within the genus Acinetobacter , and towards that end, we determined the complete rpoB gene and flanking spacer ( rplL - rpoB and rpoB - rpoC ) sequences of the 17 reference strains of Acinetobacter species and 7 unnamed genomospecies. By using complete gene sequences (4,089 bp), we clearly separated all species and grouped them into different clusters. A phylogenetic tree constructed using these sequences was supported by bootstrap values higher than those obtained with 16S rRNA or the gyrB or recA gene. Four pairs of primers enabled us to amplify and sequence two highly polymorphic parti...
Interaction effects of the insecticides monocrotophos and quinalphos (organophosphates), and cype... more Interaction effects of the insecticides monocrotophos and quinalphos (organophosphates), and cypermethrin (pyrethroid), on microbial activities in two agricultural soils-black vertisol soil and red alfinsol soil were tested for 30 days under laboratory conditions. Individual application of the three insecticides at 5, 10 and 25microg g(-1) to the soil distinctly enhanced the activities of cellulase and amylase. Insecticide combinations involving monocrotophos or quinalphos with cypermethrin yielded synergistic, antagonistic and additive interaction effects on both enzymes in the soils. At lower levels, 5 and 10microg g(-1), the insecticides in combination interacted additively or synergistically toward both enzymes. But, both combinations at the highest level of 25microg g(-1) exhibited an antagonistic interaction, with a reduction in enzyme activities to a level lower than that of the control. Interaction effects of insecticides in combinations on two enzyme activities in both soils were related to populations of cellulolytic and amylolytic organisms in soils under the impact of combination of insecticides. These interaction responses were persistent even for 30 days.
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Papers by Vijay Gundi