4.1. Development of bioinoculatns for some tree legumes useful in revegetation of mine area
- Isolation and characterization of phosphate solubilising microbes from mines
- Screening and selection of phosphate solubilisers as nursery inoculants for tree
Odisha is rich in variety of mineral resources i. e. bauxite, chromite, coal, fire clay, iron, lime stone, manganese, etc. The microflora of three mines soils i.e. Sukinda, Joda and Talcher was studied and 257 bacteria and 69 fungi were isolated and characterized for their various extracellular properties through one of the research project sanctioned by the Ministry of environment and Forests, Govt. of India (23/13/2001-RE 27th April, 2004 "Analysis of microbial community in heavy metal contaminated soils around mine site of Odisha"-2004-2006). Among them some potent phosphate solubilisers, Fe ore solubilisers, enzyme producers and antifungal organisms were obtained. The application aspect of these microbial strains especially mineral solubilization in individual and /or combination under glass house and field conditions with respect to enhancement in plant productivity and transplantation stability of some legume trees (recommended for the plantation in mine area due to their stress tolerance properties towards heavy metals) , were the main objective of this project.
Studies on Rhizoibum was worked out with isolation and/or screening protocols. In second phase, the efficiency of selected potent strains endowed with phosphate solubilization and uptake properties, iron solubilization, and nitrogen fixers was evaluated under glasshouse condition with respect to their effects on plant productivity in individually, co inoculation and combined inoculation conditions. Impact of six different phosphate-solubilizing fungi and five bacteria and four iron ore solubilizing fungi were assessed in nursery conditions on tree legumes ( Acacia auriculiformis, A.nilotica, A. leucocephala , Dalbergia sissoo and Adenenthera pavonina) was evaluated so that the treated plant could adapt to stress environment of heavy metal contaminated soils effectively. Third phase included was the preparation of nursery package /seedlings and transplantation into field soil conditions to analyze the field performance of the developed inoculants for better growth performance of selected tree legumes.
4.3. Fungal L asparaginase from mangroves of Bhitarkanika
- Culutre and nutritional optimization for large scale production of L-asparaginase
- Extraction, purification and characterization of L-asparaginases from fungi
L- asparaginase obtained from microbial sources have found wide applications in medicine as effective antitumor agent. The antitumor effect is attributed to their ability to suppress asparagine, which is necessary for tumor cell growth. L –asparaginase from bacterial origin sometimes cause severe allergic reactions. Search of new sources especially from fungal origin may be useful in the development of potential drug. The majority of L asparaginase is of intracellular in location, therefore total yield of asparaginase depends upon the cell biomass. Hence, the culture conditions and nutritional factors of L- asparaginase production were optimized for Aspergillus sp. The objective of the present experiment is to determine the L-asparaginase activity of Aspergillus sp. under different culture and nutritional conditions. Finally, the L- asparaginase extracted from cell biomass was purified through gel filtration and iron exchanged chromatography and characterized for its purity, molecular wt., km, thermal tolerance, pH requirement. The fungal species preferred starch and sorbitol as carbon and L- asparagine and L- glutamine as nitrogen sources. Addition of ionic compounds or basal nitrogen sources did not help in enhancing enzyme activity. Gel filtration and ion exchange chromatography produced pure enzyme which was later confirmed through PAGE exhibited 92.0 kda single chain peptide. L – asparaginase from the Aspergillus sp. preferred L asparagine as substrate, 7 pH , thermally stable upto 50C and showed 0.806x10-3 M Km. This study has been done under batch culture conditions. The media composition given in the present study can be further used in continuous fermentation for large scale production of L – asparaginase.
Plate -1 Gel electrophoretic separation of purified L-asparaginase from Aspergillus sp.1. Lane 1- Molecular weight markers (kda), 2- purified L-asparaginase (approx.92 kda),3- standard albumin (66 kda)
Plate 2.. Gel electrophoretic analysis of pure L –asparaginase from fungal strain 1.
Lane 1- molecular wt markers (kda), 2 – standard BSA (66 kda), 3- pure enzyme
L –asparaginase 29 kda