FORMULATION A LOW COST MEDIUM FOR COMMERCIAL SPIRULINA (Spirulina platensis) PRODUCTION

Abstract

The experiment was conducted on the rooftop of Academic Building, Sher-e-Bangla Agricultural University, Dhaka during November 2019 to March 2020 to formulate a low cost medium for commercial Spirulina production. Four treatments were used in this experiment viz. T 1 = (EcoSolv water + Zarrouk’s media), T = (EcoSolv water + Modified media), T 3 = (Freshwater + Zarrouk’s media), T II

4 2 = (Freshwater + Modified media). Freshwater + Zarrouk’s media (T ) was used standard culture media (Control) and other treatments were compared with this. These experiments were carried up to 3 rd cycles of cultivation and in 2 nd and 3 3 rd cycles of cultivation used 50% nutrients media with reuse the water. In modified media Ca 2 (PO 4 ) (Triple Super Phosphate) @ 0.4 g/l was used instead of K 2 HPO 4 2 (Dipotassium Hydrogen Phosphate) and Citric acid @ 0.8 g/l was used instead of EDTA. The experiment was outlined in the Completely Randomized Design with four replications. Significant variation was found among the treatments. Among the four treatments, highest optical density (2.38, 2.18 and 2.16), cell productivity (0.26, 0.24 and 0.24 g/l/day) and dry biomass (2.22, 2.08 and 2.04 g/l) ) was found in T 1 treatments in 1 st , 2 nd and 3 rd cycles of cultivation where second highest optical density (2.09, 1.83 and 1.95), cell productivity (0.23, 0.20 and 0.22 g/l/day) and dry biomass (1.94, 1.91 and 1.76 g/l) was observed in T

treatment in 1 st , 2 nd and 3 rd cycles of cultivation and lowest optical density (1.73) in T 3 , (1.55 and 1.66) in T 4 treatment, cell productivity (0.19 g/l/day) in T ,(0.17 and 0.18 g/l/day) in T 4 treatment, and dry biomass (1.68 g/l) in T , (1.42 and 1.46 g/l) in T 4 treatment in 1 st , 2 nd and 3 rd 3 3 cycles of cultivation. Among these treatments T

showed the highest result followed by T treatment. Considering benefit cost ratio the highest benefit cost ratio (2.34, 4.54 and 4.19) was estimated in T 2 2 treatment in 1

and 3 rd cycles of cultivation and the lowest benefit cost ratio (1.35, 2.82 and 2.75) was noted in T 3 treatment in 1 st , 2 nd and 3 rd cycles of cultivation . In every cycle of cultivation T 2 treatment showed the highest benefit cost ratio although T treatment gave the highest yield. So, EcoSolv water with Modified media is more cost effective in compare to Freshwater with Zarrouk’s media.