Proximate Composition Analysis of Spirulina platensis in Lab Scale Cultivation: Prospects of Digested Rotten Guava as a Culture Media

An experiment was conducted to evaluate the proximate composition of Spirulina platensis and growth performance in supernatant of different concentrations (supernatant of 20, 40 and 60 rotten guavas) of digested rotten guava medium (DRGM). The growth rates in terms of optical density, dry cell weight and chlorophyll a of spirulina were varied from each other. The cell weight of Spirulina was attained a maximum of 0.818 ± 0.003 mg/L in 60% DRGM followed by 0.815 ± 0.0015 and 0.809± 0.0012 mg/L in supernatant of 20 and 40%, respectively on the 10th day of culture. Similar trend was also observed in the case of optical density of the media contained Spirulina, chlorophyll a content (mg/L), total biomass (mg/L), specific growth rates (on the basis of cell weight and chlorophyll a) and total biomass of Spirulina. Cell weight of Spirulina grown in these media had highly significant (P < 0.01) correlation with the chlorophyll a content (r = 0.746) and total biomass (r = 0.742) of Spirulina. The growth performance of Spirulina in supernatant of 60% DRGM was significantly (P < 0.01) higher than that of grown in 20% and 40% DRGM. The percentage of crude protein was found 53.35 ± 0.32% in supernatant of 40% DRGM. The crude lipid was attained of 10.15 ± 0.14% in supernatant of 60% DRGM which was significantly (P < 0.05) higher than that of grown in 20% and 40% of DGRM.