Spirulina Culture in Bangladesh VIII Study of the Effects of Duration of Paddle Wheel Running Period and two Different Carbon Sources on the Commercial Cultivation of Spirulina in Bangladesh

摘要

The effect of duration of paddle wheel runing period per day and two different carbon sources (gaseous CO_2 and NaHCO_3) on the commerical cultivation of Spirulina was studied in pilot plant scale. The paddle wheel running periods were (1/2+1/2) hourwith 4 hours break, (1 +1) hours with 3 hours break. (2+2) hours with 2 hours break and (3+3) hours with 1 hour break. The optimum paddle wheel running period was found to be (2+2) hours with 2 hours break. This paddle wheel running period was selected for further cultures and it was practised for the last three years with satisfactory results. Two gaseous CO_2 treatments were done: 1 hour and 2 hours per day. 2 hours per day treatment was preferable. NaHCO_3 applications per week I kg/1000 L and 2 kg/1000 L cultures. No considerable difference was found among the two, but in 1 kg/1000 L culture, contamination was higher than in 2 kg NaHCO_3 /1000 L culture, hampering Spirulina growth. Therefore 2 kg NaHCO_3/1000 L culture was selected for forthcomingcultures and have been practised with satisfaction. Although 2 hours CO_2 treatment was as good as 2 kg NaHCO_3 /1OOO L. due to limited supply and complicated procedure for procuring CO_2, it was not suitable for use in commercial cultivation.