Abstract
Chlorella ellipsoidea and Selenastrum gracile were isolated from the experimental ponds of the Faculty of Fisheries, Bangladesh Agricultural University, Mymensingh, Bangladesh. Chlorella ellipsoidea, Selenastrum gracile and Spirulina platensis were cultured in the different concentrations of agro-based organic media such as press mud (PM), ripe bean seed powder (RBSP), cabbage powder (CP) media, and the control as Bold basal medium (BBM) and Kosaric medium (KM) in the laboratory condition. Mass culture of these microalgae was also performed in these organic media. For the preparation of the organic culture media, 0.20 g/l urea was added for all the cases. For the culture of S. platensis, in addition of urea. 6 g/l NaHCO3 added to increase the pH level of the culture media. The pure culture of the microalgae was done in two stages. In the first stage of the experiment. the media suitability was studied and all the species under study showed higher (p < 0.01) growth in PM medium than the other media on the 8th day of the culture. The other growth parameters showed the similar tendency.
In the second stage of the experiment. C. ellipsoidea showed the highest (p < 0.01) cell no. 292.43 x 10/ml in 0.60 g/l when cultured in 0.60 g/l PM medium followed by 0.40 g/ RBSP. 0.25 g/l CP media and the control BBM on the 8th day of the culture. Chlorophyll a content, optical density and the total biomass on the basis of chlorophyll a content showed the similar trend for all the cases. Selenastrum gracile gave the highest (p < 0.01) cell number 281.30 x 105/ml when grown in 0.60 g/l PM followed by 0.40 g/l RBSP and 0.25 g/l CP media at the stationary phase. The other growth parameters showed the similar trend. The promising microalgae Spirulina platensis produced the highest (p < 0.01) cell weight.