Identification of acid stress tolerant proteins from promising cyanobacterial isolates
2006
Gopalaswamy, G. | Raghu, R. | Udayasuriyam, V. | Apte, S.K., Tamil Nadu Agricultural Univ., Madurai (India). Agricultural Coll. and Research Inst.
Cyanobacterial cultures were isolated from acidic (pH:4.9-6.2) rice grown soils of Tamil Nadu. The predominant genera were Anabaena (50%), Westiellopsis (17.5%), Nostoc (15%), Oscillatoria (5%) and others were unicellulars (12.5%) viz., Microcystis, Calothrix and Phormidium. The levels of tolerance to acidity varied among these strains. They were tested and authenticated for acid tolerance capacity both under in vitro and pot culture conditions. Interestingly, Westiellopsis sp. was found to be predominant in the pH of 4.9-6.2, indicating its adaptability. The elite cultures that were tolerant to acidic conditions were characterized for growth, biomass production and biochemical constituents. The Westiellopsis sp. showed pronounced chlorophyll-a content, phycobilin pigments content, ammonia excretion and nitrogenase activity compared to the normal cultures under acidic conditions. Molecular characterization viz., isozyme and RAPD analysis, were also carried out. Three elite Westielliopsis sp. were selected, of which two strains were able to grow at an acidity level of 4.0, and one strain at an acidity level of 5.0. These three cultures, along with acid susceptible strains of Westielliopsis sp. and Anabaena sp. PCC 7120 (standard check), were given with acid shock for different time intervals. Protein profiling was done for the samples collected at different time intervals in both the acid tolerant and acid susceptible strains. Based on the presence or absence of the protein bands in the tolerant or susceptible strains some low molecular and medium molecular weight proteins are linked to confer acid tolerance.
显示更多 [+] 显示较少 [-]