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Subject: Microbiology × Author: Chaudhary, Suman × End date: 2019 × Start date: 2010 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Characterization of sulphur oxidizing bacteria and their effect on growth of mustard (Brassica juncea L.)
    (CCSHAU, 2018) Chaudhary, Suman; Goyal, Sneh
    Sulphur is a vital element for plants next to nitrogen (N), phosphorus (P), and potassium (K). It is an important constituent of proteins, enzymes, vitamins, lipids, carbohydrates, and other biomolecules. Sulphur is required for growth and development of plants especially in the crop production. Sulphur undergoes a number of biological alterations in nature carried out exclusively by microbes through sulphur cycle. Oxidation of sulphur is the most important step of S cycle which improves soil fertility. It results in the production of sulphate, which can be easily used by the plants, while the acidity produced by oxidation step helps to solubilize plant nutrients and thus improves soil health. Sulphur deficiencies in soils of tropical and subtropical regions have been recognized for many years and have been reported from over 70 countries, including India. Pyrite is good source of sulphur used as sulphur fertilizers and it can be easily used by sulphur oxidizing bacteria. In the present investigation, sulphur oxidising bacteria were isolated from different places of Haryana and evaluated for their effect on growth of mustard. A total of 130 bacteria were obtained, out of which 46 were selected on the basis of dye reduction test and further screened for sulphate production. Five bacteria namely SSD11, SSR1, SSG8, SSF17 and SSH10 were selected on the basis of maximum sulphate production for further studies and were optimized for laboratory cultural conditions. The period of 48 hrs. was found optimum incubation time for all bacteria and 30 oC was best temperature for the growth of SSD11, SSR1, SSG8, SSH10 while 35 oC was for SSF17. The pH 8 was found best for all four isolates except for SSF7, which was 6, while media having glucose carbon source was producing maximum sulphate. The best nitrogen source was found to be ammonium sulphate. After optimization, the selected bacterial isolates were evaluated for their effect on growth of mustard under pot house. There was a significant increase in the height, weight, no. of siliquae, 100 seed weight, oil content, leaves protein content, leaves chlorophyll content, viable rhizospheric bacterial count with the inoculation of bacterial isolates in comparison to control. The selected bacterial isolates were characterized on the basis of morphological and biochemical characteristics. After sequencing of 16S rRNA of bacterial isolates or molecular characterization, the four bacterial isolates were recognized as SSF17 (Phytobacter diazotrophicus), SSR1 (Enterobacter cloacae), SSD11 (Enterobacter cloacae) and SSG8 (Klebsiella oxytoca).