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Chaudhary Charan Singh Haryana Agricultural University, Hisar

Chaudhary Charan Singh Haryana Agricultural University popularly known as HAU, is one of Asia's biggest agricultural universities, located at Hisar in the Indian state of Haryana. It is named after India's seventh Prime Minister, Chaudhary Charan Singh. It is a leader in agricultural research in India and contributed significantly to Green Revolution and White Revolution in India in the 1960s and 70s. It has a very large campus and has several research centres throughout the state. It won the Indian Council of Agricultural Research's Award for the Best Institute in 1997. HAU was initially a campus of Punjab Agricultural University, Ludhiana. After the formation of Haryana in 1966, it became an autonomous institution on February 2, 1970 through a Presidential Ordinance, later ratified as Haryana and Punjab Agricultural Universities Act, 1970, passed by the Lok Sabha on March 29, 1970. A. L. Fletcher, the first Vice-Chancellor of the university, was instrumental in its initial growth.

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Subject: Microbiology × Author: Bharti × Start date: 1998 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Amelioration of salt stress in rice (Oryza sativa) by using cellulose immobilized ACC utilizing bacteria
    (CCS HAU, Hisar, 2022-09) Bharti; Pathak, D. V.
    Salt stress is one of the major abiotic stresses responsible for reducing plant growth and crop productivity. Plants subjected to excess salt initiate ionic imbalance, which leads to metabolism imbalances induced by ion toxicity and water deficit generated by hyperosmotic stress. Plant growth-promoting microbes enhance plant growth under salt stress by different mechanisms. In this context 32 bacterial strains were isolated from soil collected from salt-affected regions. Out of these14 isolates were found to tolerate NaCl concentration up to 15%(w\v). All bacterial isolates were quantitatively screened for IAA production, Ammonia production, and qualitative screening was done for zinc solubilization, potassium solubilization, phosphorous solubilization, and salt tolerance. Out of all bacterial isolates, 23 were found to utilize ACC. On the basis of ACC utilization activity, and PGPR traits, two potential isolates, STB11 and STB15 were selected for further studies. Most bio-fertilizers are unable to establish in the rhizosphere due to lack of nutrients and stress caused due to excess salt and water deficiency. In this study, for the first-time effect of bacterial cellulose in agriculture field was explored. Isolated ACC utilizing bacteria were immobilized on bacterial cellulose and evaluated for ameliorating salt stress in rice crop. A total of 26 cellulose-producing bacteria were isolated from different rotten fruits and kombucha tea. Only one (CPB26) among them was selected as a potential cellulose producer, based on the amount of bacterial cellulose produced. Central Composite Design based Response Surface Methodology (CCD-RSM) was employed to design the optimization experiments. Temp. 35C, pH 6, and incubation days 5 were found to be optimum for maximum cellulose production. Selected isolate CBP26 preferred peptone as nitrogen source and glucose as carbon source. Among metal ions, Mg2+ and Fe2+ were found to support bacterial cellulose production, highest at 0.15%(w/v) concentration, whereas Zinc did not support bacterial cellulose production. Out of four different enhancers, 1%(v\v) ethanol enhanced cellulose production. For confirmation of the bacterial cellulose, pellicle of bacterial cellulose was treated with cellulase enzyme, which digested it completely in 24h. Ultrafine Bacterial cellulose nanofibrils of size 20nm were visualized under scanning electron microscopy. FTIR spectra of bacterial cellulose obtained from analysis was found similar to those reported previously and typical bacterial cellulose thermal behavior was observed upon thermogravimetric analysis. X-RD analysis revealed that the bacterial cellulose was ordered crystalline with a crystallinity index of 77.9% and 11nm crystal size. The water holding capacity of bacterial cellulose was found to be 360%. The water evaporation rate of soil mixed with bacterial cellulose was less than the soil without bacterial cellulose. Dried bacterial cellulose was converted to powder form to carry out further studies. Selected bacterial isolates STB11 and STB15 were immobilized on powdered bacterial cellulose by absorption and incubation method. After the incubation step, immobilized bacterial cells were coated on rice seeds (Pusa 1121). Sowing of these coated seeds was done in pots (4 seeds/pot) under pot house conditions. Different RSC water i.e.,4, 8, 10 was used for irrigation of crops. The selected bacterial isolates were found to be effective in terms of rice plant growth such as plant height varied from 13cm -78.5cm from 15 to 90 days after sowing (DAS), maximum in T20 (RSC8+BCI STB15) 78.5cm at 90 DAS, root length (7.99-29.9cm), maximum in T21 (RSC 10+BCI STB15) 29.9cm, fresh weight of shoot and root varied between 1.49- 3.43 and 0.3-1.34g/plant respectively, dry shoot and root weight varied between 0.15-0.49 and 0.15-0.18g/plant respectively. Selected bacterial isolates also enhanced N (2.31- 13.66mg/plant-1) and P (0.10-0.27mg/plant-1) and increased superoxide dismutase activity in plants (1.07-3.54Unit/g FW), maximum in T20 (RSC8+BCI STB15) 3.5 unit/g FW. Rhizospheric bacterial viable count of rice plants was found maximum at 60 days after sowing in T20 followed by T21 i.e., 8.09 and 8.06 log Cfu/g of soil, respectively. On the basis of partial 16s rDNA sequencing bacterial isolate STB11 was identified as Bacillus pumilus, STB15 as Enterobacter spp. Bacterial cellulose producer CPB26 was identified as Gluconacetobacter liquefaciens. All the three identified bacterial gene 16s rDNA sequences were submitted to NCBI and allotted the accession numbers.