PERFORMANCE CHARACTERIZATION OF SELECTED INDIGENOUS MICROALGAE ISOLATED FROM DIFFERENT MARINE AND FRESHWATER SOURCES OF BANGLADESH

Abstract

This study includes information on isolating some indigenous freshwater and marine microalgae and determining their growth rate, pigmennts, and proximate composition in order to take advantage of the great potentiality of local microalgae. For microalgae isolation streak plating method in agar, serial dilution and capillary pipetting was performed and for the evaluation of growth performance. Selected microalgae (Chlamydomonas sp., Navicula sp., Gonyostomum sp., Nannochloropsis sp., Choricystis sp., Chromochloris sp., Tetraedron sp., Chlorobotrys sp. Coelastrella sp., Kirchneriella sp. Oscillatoria sp1 and Oscillatoria sp4) were mass cultured in commercial Bold Basal Medium (BBM) and Conway Medium, harvested at their stationary phases to determine the pigments content (chlorophyll-a, chlorophyll-b, chlorophyll-c, carotenoid and phycobiliproteins) and proximate composition (protein, lipid and carbohydrate). Results showed that, onset of stationary phase (9–14 days) varied among the fourteen species where in the stationary phase, significantly higher (p˂0.05) cell density was observed in Gonyoatomum sp. All microalgae showed chlorophyll-a as the main pigment component, where Oscillatoria sp2 showed significantly highest (p˂0.05) chlorophyll-a (22.72±0.04 µg/mL). On the other hand, highest chlorophyll b (2.75±0.07 µg/mL) and carotenoid content (6.888±0.08 µg/mL) was recorded in Chlamydomonas sp. Moreover, total phycobiliproteins was also significantly higher (p˂0.05) in Oscillatoria sp4. (89.80±0.12 mg/g) and significantly lowest (p˂0.05) in Nannochloropsis sp. (0.89±0.04 mg/g). Significantly higher and lower (p<0.05) amount of total protein was recorded in Navicula sp. (59.5123±0.78% dry weight) and Krichneriella sp. (17.276±0.76 % dry weight), respectively. Similarly, highest and lowest (p<0.05) amount of lipid content was recorded in Gonyoatomum sp. (27.4±0.695 dry weight) and Oscillatoria sp3 (9.07±0.07%dry weight), respectively. In addition, carbohydrate content was highest (p < 0.05) in Kirchneriella sp. The results on amino acids and fatty acids revealed significant differences (p < 0.05) across these experimental species in numerous instances