Abstract:
The study “The effect of the N/P ratios on the growth of cyanobacteria at different salinities” was conducted to identify the effect of N/P ratio to the development of cyanobacteria in various saline levels in the experiment conditions. The three prevailing species, Anabaena sp., Lyngbya sp., and Microcystis sp., which were isolated from the shrimp ponds, were cultured in the conditions of different salinities (0, 5, 10, 15, and 20 ppt) and different N/P ratios (2/1, 4/1, 6/1, and 8/1). In the experimental conditions, Anabaena sp. thrived well in the salinity of 5 ppt to 15 ppt and developed the best in 10 ppt. Lyngbya sp. thrived in all the ratios of salinity and grew best at 10 ppt. Microcystis sp. thrived in salinities from 0 ppt to 10 ppt and grew best at the salinity of 5 ppt. Anabaena sp. grew best in the N/P ratio = 8/1 and 10 ppt salinity, grew poorly in the N/P ratio = 2/1 to 4/1 and the salinity of 0 ppt. Lyngbya sp. grew best in the N/P ratio = 8/1 and 10 ppt salinity, grew slowly in the N/P ratio = 2/1 to 4/1 and the salinity of 20 ppt. Mycrocystis sp. grew best in the N/P ratio = 8/1 and 5 ppt salinity, grew badly in the N/P ratio = 2/1 to 4/1 and the salinity of 20 ppt.
Keywords:
Anabaena sp., cyanobacteria, Lyngbya sp., Microcystis sp., N/P ratio, salinity.