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Subject: Microbiology × End date: 2006 × Start date: 2006 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Siderophore production by pseudomonas species and its role in disease control of green gram (Vigna radiata) caused by rhizoctonia solani
    (CCSHAU, 2006) Sahu, Govind Kumar; Sindhu, S.S.
    In the present study, sixty-five bacterial isolates were obtained from the rhizosphere soil of chickpea and green gram plants by plating serial dilutions on King’s B media. Fifty-eight isolates were identified as Pseudomonas based on colony morphology, pigment characteristics and oxidase test. These fifty-eight Pseudomonas isolates alongwith 22 reference strains were tested for siderophore production using universal chromo-azurol S assay method on MM9 medium and iron-deficient succinate medium. Thirty-seven Pseudomonas strains/isolates were found to produce siderophore on MM9 medium and the diameter of halo zone varied with different Pseudomonas isolates. Production of siderophores was found more on MM9 medium as compared to succinate medium. Bacterial colony growth (G) and halo zone (H) size were measured on MM9 medium and H/G ratios varied from 1.44 to 10.24 in different Pseudomonas isolates. Seventeen Pseudomonas isolates were used for optimization of cultural conditions for enhanced production of siderophores. Replacement of glucose with sucrose, sodium gluconate or sodium malate supported siderophore production whereas arabinose addition repressed siderophore production in most of the Pseudomonas isolates. Increased concentration of ammonium chloride (0.2%) also decreased siderophore production. Addition of Fe-EDTA salt at low 5 M concentration showed less suppressive effect whereas at 10 M concentration more inhibitory effect on siderophore production was observed. Production of siderophore was found more at pH 7.0 in comparison to cultures grown in media with pH 8.0 and pH 6.0. Siderophore producing Pseudomonas isolates inhibited the growth of phytopathogenic fungi Fusarium oxysporum, Rhizoctonia solani and Pythium aphanidermatum. Large inhibition zones of fungal growth were observed on PDA medium in comparison to NA medium plates. Coinoculation of Pseudomonas cultures caused reduction in root rot disease symptoms under pot house conditions and disease control varied from 33.4 to 100 per cent with different Pseudomonas cultures. Coinoculation of Pseudomonas isolates MP20, MPS54, CP56 and CPS67 with Bradyrhizobium strain SMR15 also enhanced the nodule number, nodule fresh weight and plant dry weight as compared to Bradyrhizobium-inoculated or uninoculated control plants at 30, 45 and 60 days of plant growth. Coinoculation of Pseudomonas strain CP56 with Bradyrhizobium strain and R. solani showed maximum increase (275.8%) in plant dry weight at 60 days in comparison to control plants and completely suppressed the root rot disease under pot house conditions. The better performance of siderophore-producing Pseudomonas strains in relation to symbiotic performance and disease control indicated that Pseudomonas strains could be exploited for disease suppression and plant growth promotion under field conditions.
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    ThesisItemOpen Access
    Potato starch as substrate for ethanol production by Saccharomyces cerevisiae
    (CCSHAU, 2006) Poonam; Garg, F.C.
    Ethanol is one of the most important feed stock for industrial chemicals and is also used as liquid fuel. In India, ethanol is produced by fermentation of molasses by S. cerevisiae. In recent years because of decontrol of molasses, there is limited availability of good quality molasses and ethanol production has not exceeded 2.7 billion liters. So under new regulations, a new look need to be taken with regard to easily available and renewable substitutes such as starch for ethanol production. Potato is considered as potential substrate because of high content of starch and its increase in cultivation year after year. The concentration of slurry in potato grates and mashed potato for liquefaction by enzyme Termamyl-100 was found to be 1:1 & the amount of enzyme required for liquefaction of slurries prepared from potato grates and mashed potato was found to be 750 and 500 μl for 100 g of material respectively. The homogenous slurry of potato flour was obtained using ratio of potato flour : water
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    ThesisItemOpen Access
    Impact of clodinafop herbicide on soil microflora and their biochemical activities in wheat field soil
    (CCSHAU, 2006) Saini, Babita; Suneja, Sunita
    In the present investigation, effect of long term use of clodinafop herbicide (used as permanent and rotational herbicide) on soil microbial populations and their activities in wheat field soil was studied. Soil samples collected before the application of herbicide were analyzed for soil chemical properties. Soil was of clay loam type. Soil pH ranged from 8.4-8.6 and EC ranged from 0.23-0.44 dSm-1. Organic carbon and total N were more in green manuring (GM) treatments than without green manuring (WGM) treatments. Total bacterial population was more in GM treatments than WGM treatments. At 15 days after the treatment (DAT) of herbicide, bacterial population was significantly less in rotational herbicide treated plot than weedy control under both GM and WGM conditions. At 30 & 60 DAT, bacterial count was more in permanent herbicide treated plots than rotational herbicide treated plots and weedy and weed free controls. Free living diazotrophs count was also more in GM treatments than WGM treatments. At 30 DAT, count was more in herbicide treated plots than weedy and weed free controls of GM condition while in WGM condition, there was not much difference in the population of different treatments. Ammonium oxidizer population increased after the application of herbicide in all the treatments upto 30 DAT. In GM condition, population was less in permanent herbicide treated plot at 15 DAT and in both (permanent and rotational) herbicide treated plots at 30 DAT as compared to weedy and weed free controls while in WGM condition, population was less only in rotational herbicide treated plot than weedy control at 15 DAT. Nitrite oxidizer population decreased after the application of herbicide in all the treatments. At 15 DAT, population was less in herbicide treated plots than weedy control in GM condition while in WGM condition, population was less only in rotational herbicide treated plot than weedy control. At 30 DAT, population increased and was significantly higher in permanent herbicide treated plots than weedy and weed free controls. Basal respiration, as indicated by carbon dioxide evolved, was slightly more in herbicide treated plots than weedy and weed free controls at 15 DAT and only in rotational herbicide treated plot at 30 DAT under both GM and WGM conditions. Later on, with the progress of time after application of herbicide, not much differences were observed in the basal respiration of different treatments under both GM and WGM conditions. Dehydrogenase activity was slightly higher in herbicide treated plots than weedy control of GM condition at 30 & 60 DAT while in WGM condition, activity was significantly less in herbicide treated plots than weedy control. Although herbicide treatments of GM condition had higher alkaline phosphatase activity than herbicide treatments of WGM condition but activity was less in herbicide treatments than weedy control at 15 & 30 DAT under GM condition while in WGM condition, enzyme activity in herbicide treated plots was not less than weedy control.
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    ThesisItemOpen Access
    Effect of digested distillery effluent on soil microbial population and plant growth of wheat (Triticum aestivum)
    (CCSHAU, 2006) Deora, Anupama; Kukreja, Kamlesh
    The present investigation was carried out to study the effect of different concentrations of digested distillery effluent on soil microbial population, seed germination and plant growth of wheat. The microbial population increased with increase in concentration of effluent up to 20% and slightly decreased with further increase in concentration of effluent. The count increased up to 60 days of incubation and later on decreased at 90 days of incubation but trend remained the same. Lower concentrations of effluent (10 and 20%) were not inhibitory to seed germination. Germination rate was poor in 50% effluent concentration while higher concentrations (75 and 100%) of effluent lead to complete failure of seed germination. Under pot house conditions also, lower concentrations (10 and 20%) of effluent were not inhibitory to seed germination but higher concentration (50%) of effluent suppressed and delayed germination rate. Higher concentration (50%) of effluent was inhibitory to plant growth when plants were irrigated with effluent before germination followed by when always irrigated with effluent after germination. Plant growth was completely suppressed when 50% effluent was used for irrigation through out the experiment. Maximum plant growth was obtained in 50% effluent concentration (comparable to 100% RDF) followed by 20% effluent concentration (comparable to 75% RDF) when plants were irrigated with effluent after germination at every 20 days of interval. When pots were irrigated with effluent only before germination, 20% effluent concentration gave better results in comparison to 10% effluent concentration. However, significantly higher plant growth was obtained when plants were irrigated with 10% effluent always after germination which was comparable to 75% RDF.
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    ThesisItemOpen Access
    Isolation and characterization of lipase producing bacteria
    (CCSHAU, 2006) P. Periasamy; Garg, F.C.
    Lipases are enzymes that are widely distributed among microorganisms, animals and plants. However, microbial lipase are the enzymes with diversified properties and substrate specification which make them useful for industrial application. Lipase of pathogenic bacteria such as Cornybacterium acnes, Mycoplasma, play a crucial role in the etiology of diseases. Whereas some other bacterial lipases have been used in the bioremediation of environmental problem, in domestic sewage etc. In addition to this microbial lipases spoil the dairy and other foods containing fats, some times even at refrigerated temperature. Lipase have role to play in detergent, paper, cosmetic, and agrochemical industries. (Jagges et al., 1996). In view of the importance and application of bacterial lipases the present study was conducted. Eight different samples from 4 different sources were collected and 73 bacterial cultures that produced lipase were isolated on the basis of formation of zone of clearance on solid medium. For further screening 29 isolates were selected and the enzyme activity was determined by titrimetric method. The screening was also done by well method. Out of 29 isolates 5 i.e. isolate No. 18, 21, 22, 47 and 48 showed better lipase activity than others. Among the five isolates, No. 21 and 18 produced maximum lipase, 21.5 Units/ml and 18.3 Units/ml respectively and thus were selected for further studies. Both the isolates produced maximum enzyme at 30ºC and pH 8. Enzyme activity was maximum at 60ºC for isolate No. 21 and 50ºC for isolate No. 18. The optimum pH for the activity of lipase from both isolates was found to be 8.0. Under shake culture condition both the isolates produced maximum amount of lipase than under stationary conditions. Glucose and tryptone were the best sources of carbon and nitrogen respectively for production of lipase in both the isolates. The cultural, morphological, biochemical characteristics indicate that lipase activity is present in a variety of bacteria.
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    ThesisItemOpen Access
    Genetic divergence and correlation coefficient analyses for grain yield, its components and quality traits in bread wheat
    (CCSHAU, 2006) Sharma, Vivek; Pawar, I.S.
    In the present investigation, 75 genotypes of wheat were grown in Randomized block design with three replications accommodating each genotype in 3m long paired row plot with row to row and plant to plant spacing at 23cm and 10cm, respectively, at the experimental research area of wheat section, Department of Plant Breeding, CCS Haryana Agricultural University, Hisar during ‘rabi’ season of 2004-05 to determine variability, correlation, path coefficient, genetic divergence and identification of genetically diverse and agronomcially desirable germplasm. Observations on five competitive plants for 11 metric traits were recorded. Sustatnial amount of genetic variability was observed for all the traits studied. The grain yield per plant showed positive and significant correlation with ear length, days to maturity, tiller number per plant, total biomass and number of grains per ear. The path coefficient analysis recorded that total biomass, tiller number per plant and number of grains per ear were the main contributors towards grain yield per plant. On basis of D2 values, the genotypes were grouped into eleven clusters. There were little association between clustering pattern and agro-ecological distributions of genotypes. However, the genotypes of same agro-ecological had shown some tendency to come together in same cluster. The genotypes included in clusters III, VI, IX and X were identified as divergent as well as with higher mean values for important yield contributing traits. The genotypes viz. UP-2338, PBW-343, WH-283, PBW-502, WH-711 and Veery were divergent and superior performers for most of the yield and quality attributing traits and could be exploited in future wheat breeding programme.
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    ThesisItemOpen Access
    Colonisation behaviour of gluconacetobacter diazotrophicus in cotton plant
    (CCSHAU, 2006) Chawla, Niti; Bansal, R.K.
    Studies on the colonisation behaviour of Gluconacetobacter diazotrophicus 35-47 introduced as seed treatment was undertaken in root-knot nematode (Meloidogyne incognita) infected and healthy cotton (Gossypium hirsutum) cv. H-1098 plants grown in sterilized and natural field soil in green house. G. diazotrophicus 35-47 inoculation significantly reduced root-knot disease intensity and also enhanced plant growth parameters of both nematode infected and healthy cotton plants in sterilized as well as natural field soil. Studies on colonisation behaviour of the bacterium has indicated that it colonised root surface and not the internal tissues of the cotton plant, suggesting that it is a ‘root-surface coloniser’ and not the ‘endophyte’ of cotton. From the results, it is also evident that bacterium could grow upto last day of observation (90 DAS) of plant growth in natural field soil in healthy plants, however, nematode infection reduced bacterial multiplication. Optimisation study on the cotton root surface sterilisation showed that exposure in 10% sodium hypochlorite (containing 4% free chlorine) solution for 15 minutes followed by 5-6 times rinsing in sterile distilled water is sufficient to achieve complete surface sterility.