Marine cyanobacteria constitute a vast potential resource in various applications such as food, feed, fuel, fertilizer, medicine and in combating pollution. Growth of cyanobacteria cultures are affected by several environmentsl factors. In the present study, the influence of pH, salinity and temperature on the growth of six species of cyanobacteria isolated from Arabian Sea coast of
Karnataka was investigated. The axenic cultures were maintained in sterilized f/2 culture media. pH of the media was adjusted to 6.3, 7.5, 8.4, 9.5 and 10.2 with the help of 1 N NaOH and 1 N HCl, whereas salinity was adjusted to 9 ppt, 16 ppt, 25 ppt, 32 ppt and 40 ppt by diluting the media with double-distilled water or by varying the amount of NaCl in the media. The effect of temperature was studied by incubating the cultures at 20˚C, 30˚C, 40˚C and 50˚C. The growth of the isolates were determined in terms of their chlorophyll-a content. All isolated species preferred near neutral to alkaline pH. High pH levels adversely affect the growth of isolates and significantly reduced at pH 10.6. All isolates were able to grow at all salinities. The best growth was seen at 16 ppt and 25 ppt. All isolates showed best growth at 20˚C and 30˚C. The growth has ceased at 40˚C and 50˚C. These factors are useful for establishing the appropriate culture conditions for optimizing the growth of cyanobacteria and also helpful to understand their response to varying environmental factors.
Rai S. V. & Rajashekhar M., 2016. Effect of pH, salinity and temperature on the growth of six species of cyanobacteria isolated from Arabian Sea coast of Karnataka. International Journal of Biosciences and Technology 9(1):1-6. Article.
