The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform
Neeru Narula - One of the best experts on this subject based on the ideXlab platform.
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Studies on in vitro production of antimicrobial substances by Azotobacter Chroococcum isolates/mutants
2001Co-Authors: Satbala Verma, Neeru Narula, Vivek Kumar, Wolfgang MerbachAbstract:An attempt was made to study the in-vitro production of antimicrobial/antifungal substances by various strains of Azotobacter Chroococcum against various plant pathogens. In addition, nature and role of these substances were studied on the germination and reduction in disease (index) by Rhizoctonia solani in mustard crop. About 37 % of Azotobacter Chroococcum isolates/mutants showed a zone of inhibition against Rhizoctonia solani and 25 % against Xanthomonas campestris. Approximately 16 % of isolates/mutants of A. Chroococcum were siderophore positive (sid + ), The antimicrobial substances in Azotobacter were found to be extracellular, proteinaceous in nature and seem to be associated with some complex material also. Seed germination of mustard Brassica juncea (L.) cv. RH 30' increased when treated with A. Chroococcum isolate/mutants (29, 18 and mala 27) alone and in combination with plant pathogens, i. e., Rhizoctonia solani and Xanthomonas campestris. A soil pouch experiment conducted on B. juncea (L.) under pot house conditions showed that root rot caused by R. solani was significantly reduced by all the selected Azotobacter isolates/mutants. However, percent disease index was minimum with A. Chroococcum 29, which was sid - also indicating that siderophore production alone might not have a role in decreasing plant pathogenicity.
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In vitro production of plant growth regulators (PGRs) by Azotobacter Chroococcum
Indian Journal of Microbiology, 2001Co-Authors: Alka Verma, Kamlesh Kukreja, D. V. Pathak, Sunita Suneja, Neeru NarulaAbstract:Plant growth regulators like gibberellin, kinetin and Indole acetic acid (IAA) were detected by thin layer chromatography (TLC) and other conventional methods In the culture filterate of Azotobacter Chroococcum-strains. Afew strains produced all the three plant growth regulators (PGRS) while others produced either one or two of these. The production of these PGRs was further confirmed by bioassays.
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studies on in vitro production of antimicrobial substances by Azotobacter Chroococcum isolates mutants
Zeitschrift für Pflanzenkrankheiten und Pflanzenschutz, 2001Co-Authors: Satbala Verma, Neeru Narula, Vivek Kumar, Wolfgang MerbachAbstract:An attempt was made to study the in-vitro production of antimicrobial/antifungal substances by various strains of Azotobacter Chroococcum against various plant pathogens. In addition, nature and role of these substances were studied on the germination and reduction in disease (index) by Rhizoctonia solani in mustard crop. About 37 % of Azotobacter Chroococcum isolates/mutants showed a zone of inhibition against Rhizoctonia solani and 25 % against Xanthomonas campestris. Approximately 16 % of isolates/mutants of A. Chroococcum were siderophore positive (sid + ), The antimicrobial substances in Azotobacter were found to be extracellular, proteinaceous in nature and seem to be associated with some complex material also. Seed germination of mustard Brassica juncea (L.) cv. RH 30' increased when treated with A. Chroococcum isolate/mutants (29, 18 and mala 27) alone and in combination with plant pathogens, i. e., Rhizoctonia solani and Xanthomonas campestris. A soil pouch experiment conducted on B. juncea (L.) under pot house conditions showed that root rot caused by R. solani was significantly reduced by all the selected Azotobacter isolates/mutants. However, percent disease index was minimum with A. Chroococcum 29, which was sid - also indicating that siderophore production alone might not have a role in decreasing plant pathogenicity.
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Pesticide resistance among Azotobacter Chroococcum soil isolates and mutants
Microbiological Research, 1994Co-Authors: N Gupta, K. Lakshminarayana, R Gahlot, Neeru NarulaAbstract:Abstract Resistance among soil isolates and mutants of Azotobacter Chroococcum was studied on pesticides like lindane (gamma-hexa chloro cyclohexane) 2,4,D (2,4 dichlorophenoxy acetic acid) and aldrin. The results indicate that resistance to pesticides is common among A. Chroococcum soil isolates and mutants. Decreased resistance with increasing concentrations of pesticides specially in case of aldrin was observed.
Francisco Javier Cejudo - One of the best experts on this subject based on the ideXlab platform.
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Cyanate is transported by the nitrate permease in Azotobacter Chroococcum
FEMS Microbiology Letters, 1996Co-Authors: María De La Cruz Muñoz-centeno, Antonio Paneque, Francisco Javier CejudoAbstract:Azotobacter Chroococcum cells exhibiting the capacity to take up nitrate actively could transport [14C]cyanate. This activity was dependent on the nitrogen source present in the culture medium, ammonium acting as a repressor and nitrate as an inducer. The uptake of cyanate required metabolic energy and was absent from A. Chroococcum TR1, a mutant strain lacking the nitrate transport system, but was present at wild-type levels in A. Chroococcum E4, a mutant strain deficient in nitrate reductase. These results show that cyanate is transported by the nitrate permease in A. Chroococcum and therefore [14C]cyanate may be useful as a nitrate analogue for studies on nitrate transport.
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Nitrate permease from Azotobacter Chroococcum
Physiologia Plantarum, 1993Co-Authors: Antonio Paneque, Maria T. Ruiz, María De La Cruz Muñoz-centeno, Francisco Javier CejudoAbstract:Active transport systems in bacteria can be divided into two groups: those that are osmotic shock-resistant with one single membrane protein, and those that are shock-sensitive and have a membrane-bound protein complex plus a soluble periplasmic protein. Whether the bacterial assimilatory nitrate transport falls into the one or the other of these two groups has not been studied before. We report that nitrate uptake by the strictly aerobic, N 2 -fixing heterotrophic bacterium Azotobacter Chroococcum is sensitive to osmotic shock. The polypeptide composition of cytoplasmic membranes changes in response to the nitrogen source available to the cells
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Nitrite uptake in Azotobacter Chroococcum
Archives of Microbiology, 1992Co-Authors: Maria T. Ruiz, María De La Cruz Muñoz-centeno, Francisco Javier Cejudo, Antonio PanequeAbstract:Nitrite uptake is made up of two components in Azotobacter Chroococcum, a passive diffusion, presumably of nitrous acid, and an active transport of nitrite which uses the nitrate transport system. Only the active component is under regulatory control.
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Regulation of Azotobacter Chroococcum invertase
Archives of Microbiology, 1991Co-Authors: Mercedes G. Vega, Francisco Javier Cejudo, Antonio PanequeAbstract:Synthesis of the Azotobacter Chroococcum invertase was found to be dependent on sucrose or raffinose in the growth medium. The activity of this invertase was slightly inhibited by glucose. Fructose, which by itself did not affect the enzyme activity, protected invertase from glucose inhibition. Per cent residual activity plotted against glucose concentration, and Hill plot indicated that this monosaccharide binds to one interacting site of the enzyme. The results show that regulation of this prokaryotic enzyme clearly differs from that of eukaryotic orgnisms.
Zubin Xie - One of the best experts on this subject based on the ideXlab platform.
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description of Azotobacter Chroococcum subsp isscasi subsp nov isolated from paddy soil and establishment of Azotobacter Chroococcum subsp Chroococcum subsp nov
International Journal of Systematic and Evolutionary Microbiology, 2020Co-Authors: Haiyang Jin, Hui Wang, Yanhui Zhang, Zhibin Lin, Benjuan Liu, Xiaojie Wang, Qi Liu, Xingwu Lin, Zubin XieAbstract:Three aerobic, asymbiotic, N2-fixing bacterial strains, designated P205T, P204 and P207, were isolated from a paddy soil in Yanting County, China. Based on 16S rRNA gene sequences, the three strains were closely related to Azotobacter Chroococcum IAM 12666T (=ATCC 9043T) (99.00–99.79 % similarities). Strain P205T formed an individual branch distinct from the other two newly isolated strains and other related type strains in phylogenetic analyses based on 16S rRNA gene and 92 core genes. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA–DNA hybridization (dDDH) values based on genome sequences of strain P205T and A. Chroococcum ATCC 9043T, P204, P207 were near or slightly higher than the thresholds for species circumscription (95–96, 95–96 and 70 %, respectively), and the dDDH values were significantly lower than the threshold for delineating subspecies (79–80 %), which strongly supported that strain P205T belonged to A. Chroococcum but was a novel subspecies distinct from the type strain of A. Chroococcum . This finding was further corroborated by distinct phenotypic characteristics such as growth in Luria–Bertani (LB) medium, carbon source utilization and chemical sensitivity to vancomycin. Therefore, strain P205T represents a novel subspecies of Azotobacter Chroococcum , for which the name Azotobacter Chroococcum subsp. isscasi subsp. nov. is proposed with the type strain P205T (=KCTC 72233T=CGMCC 1.16846T=CCTCC AB 2019080T). The subspecies Azotobacter Chroococcum subsp. Chroococcum subsp. nov. is created automatically with the type strain ATCC 9043T (=DSM 2286T=JCM 20725T=JCM 21503T=LMG 8756T=NBRC 102613T=NCAIM B.01391T=NRRL B-14346T=VKM B-1616T).
María De La Cruz Muñoz-centeno - One of the best experts on this subject based on the ideXlab platform.
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Cyanate is transported by the nitrate permease in Azotobacter Chroococcum
FEMS Microbiology Letters, 1996Co-Authors: María De La Cruz Muñoz-centeno, Antonio Paneque, Francisco Javier CejudoAbstract:Azotobacter Chroococcum cells exhibiting the capacity to take up nitrate actively could transport [14C]cyanate. This activity was dependent on the nitrogen source present in the culture medium, ammonium acting as a repressor and nitrate as an inducer. The uptake of cyanate required metabolic energy and was absent from A. Chroococcum TR1, a mutant strain lacking the nitrate transport system, but was present at wild-type levels in A. Chroococcum E4, a mutant strain deficient in nitrate reductase. These results show that cyanate is transported by the nitrate permease in A. Chroococcum and therefore [14C]cyanate may be useful as a nitrate analogue for studies on nitrate transport.
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Nitrate permease from Azotobacter Chroococcum
Physiologia Plantarum, 1993Co-Authors: Antonio Paneque, Maria T. Ruiz, María De La Cruz Muñoz-centeno, Francisco Javier CejudoAbstract:Active transport systems in bacteria can be divided into two groups: those that are osmotic shock-resistant with one single membrane protein, and those that are shock-sensitive and have a membrane-bound protein complex plus a soluble periplasmic protein. Whether the bacterial assimilatory nitrate transport falls into the one or the other of these two groups has not been studied before. We report that nitrate uptake by the strictly aerobic, N 2 -fixing heterotrophic bacterium Azotobacter Chroococcum is sensitive to osmotic shock. The polypeptide composition of cytoplasmic membranes changes in response to the nitrogen source available to the cells
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Nitrite uptake in Azotobacter Chroococcum
Archives of Microbiology, 1992Co-Authors: Maria T. Ruiz, María De La Cruz Muñoz-centeno, Francisco Javier Cejudo, Antonio PanequeAbstract:Nitrite uptake is made up of two components in Azotobacter Chroococcum, a passive diffusion, presumably of nitrous acid, and an active transport of nitrite which uses the nitrate transport system. Only the active component is under regulatory control.
Haiyang Jin - One of the best experts on this subject based on the ideXlab platform.
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description of Azotobacter Chroococcum subsp isscasi subsp nov isolated from paddy soil and establishment of Azotobacter Chroococcum subsp Chroococcum subsp nov
International Journal of Systematic and Evolutionary Microbiology, 2020Co-Authors: Haiyang Jin, Hui Wang, Yanhui Zhang, Zhibin Lin, Benjuan Liu, Xiaojie Wang, Qi Liu, Xingwu Lin, Zubin XieAbstract:Three aerobic, asymbiotic, N2-fixing bacterial strains, designated P205T, P204 and P207, were isolated from a paddy soil in Yanting County, China. Based on 16S rRNA gene sequences, the three strains were closely related to Azotobacter Chroococcum IAM 12666T (=ATCC 9043T) (99.00–99.79 % similarities). Strain P205T formed an individual branch distinct from the other two newly isolated strains and other related type strains in phylogenetic analyses based on 16S rRNA gene and 92 core genes. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA–DNA hybridization (dDDH) values based on genome sequences of strain P205T and A. Chroococcum ATCC 9043T, P204, P207 were near or slightly higher than the thresholds for species circumscription (95–96, 95–96 and 70 %, respectively), and the dDDH values were significantly lower than the threshold for delineating subspecies (79–80 %), which strongly supported that strain P205T belonged to A. Chroococcum but was a novel subspecies distinct from the type strain of A. Chroococcum . This finding was further corroborated by distinct phenotypic characteristics such as growth in Luria–Bertani (LB) medium, carbon source utilization and chemical sensitivity to vancomycin. Therefore, strain P205T represents a novel subspecies of Azotobacter Chroococcum , for which the name Azotobacter Chroococcum subsp. isscasi subsp. nov. is proposed with the type strain P205T (=KCTC 72233T=CGMCC 1.16846T=CCTCC AB 2019080T). The subspecies Azotobacter Chroococcum subsp. Chroococcum subsp. nov. is created automatically with the type strain ATCC 9043T (=DSM 2286T=JCM 20725T=JCM 21503T=LMG 8756T=NBRC 102613T=NCAIM B.01391T=NRRL B-14346T=VKM B-1616T).
