PHYSIOLOGICAL AND GROWTH PERFORMANCE OF CYANOBACTERIUM, PHORMIDIUM FRAGILE UNDER EXPOSURE TO DIFFERENT LIGHT CONDITIONS
|Jehan Saud AL-Abrahim1, Mudawi Mukhtar Elobeid2, Afrah Eltayeb Mohammed 1,*
|Corresponding Author: [email protected] Tel. 00966118236098, Fax. 00966-118236095|
Light is the most important environmental factor that critically affects growth and development of algae through its immediate influence on photosynthesis. In such a process, the initial phase (light reactions) involves light absorption resulting in the formation of intermediate energy compounds (ATP and NADPH), which would later be utilized for driving the second phase of photosynthesis (carbon fixation) in the Calvin cycle. In the current investigation the principal objective was to evaluate the effect of different light conditions on the physiological and growth behaviour of the Cyanobacterium, Phormidium fragile. To realize that goal carbohydrates content as well as dry mass production were analyzed and determined. Phormidium fragile tissues were propagated in sterilized flasks containing an appropriate algal culture and subjected to four different light conditions: sun light, laboratory light, white lamb light (control) and darkness. Analysis of carbohydrates content showed that the algal growth under both laboratory and darkness conditions exhibited significantly higher values (106 mg and 81 mg, respectively) relative to control (38 mg). On the other hand, the dry matter content was significantly lower in darkness and laboratory conditions (30 and 35 mg, respectively) compared to that of the control (75 mg). Based on these findings our present study provided additional supporting evidence for the significance of light energy as a determinant factor in the photosynthetic activity of algae in relation to dry mass accumulation and carbohydrate metabolism. Further studies need to be carried out in order to validate our conclusions.