<span style="font-size:15.0pt;mso-bidi-font-weight:bold" lang="EN-GB">Iron induced modifications in physiological attributes and SDS-PAGE of whole cell proteins pattern of <i style="mso-bidi-font-style:normal">Anabaena</i> PCC 7120 and its derivative <i style="mso-bidi-font-style:normal">ntc</i>A mutant </span>

Abstract

87-93The influence of the various levels of iron (0-500 µM) on Anabaena sp. PCC 7120 and its derivative CSE2 mutant impaired in ntcA gene have been investigated to determine the requirement of specific concentration of iron for the regulation of photosynthetic pigments, cellular constituents, heterocyst spacing pattern, enzyme activities and SDS-PAGE of whole cell protein profiling. Iron at lower concentrations (≤50 µM) causes increase in chlorophyll a, carotenoid, phycocyanin, carbohydrate, protein, nitrogenase, nitrate reductase and glutamine synthetase activities in wild type as well as in<i style="mso-bidi-font-style: normal"> mutant strain (except nitrogenase and nitrate reductase activities), while higher concentrations (>50 µM) were toxic and cause significant reductions in these physiological attributes. Nitrogenase and nitrate reductase activity were found absent in <i style="mso-bidi-font-style: normal">ntcA mutant. Further, 50 µM iron concentration also supported the maximum heterocyst frequency with changed heterocyst spacing pattern in wild type, whereas no visible sign of heterocyst development was observed in mutant strain. SDS-PAGE of whole cell protein revealed the occurrence of maximum number of bands at 50 µM iron concentration in both wild type and mutant strain. Results suggested that 50 µM of iron concentration was the specific concentration (critical concentration) that supported optimal physiological and biochemical activities in Anabaena 7120 and its mutant strain CSE2 (ntcA). </span