Smart Culture of Spirulina Using Supernatant of Digested Rotten Tomato (Solanum Lycopersicum) to Produce Protein, Bio-Fuel and Bio-Electricity

An experiment was conducted for the production of protein, bio-fuel and bio-electricity from the culture system of Spirulina platensis (Gomont) in supernatant of three different amount of digested rotten tomato (Solanum lycopersicum), and Kosaric Medium (KM) as control. Three different concentrations such as 25, 50 and 75% rotten tomato were allowed to digest under aeration. After 17 days, the colorless supernatant was screened and taken in 1.0 L conical flask with three replications. Then, Spirulina platensis was inoculated to grow in these three media (treatments) with the addition of 9.0 g/L NaHCO₃ and micronutrients, and also in KM as control for a period of 14 days. The cell weight, optical density, chlorophyll a and total biomass  of spirulina was attained to the  maximum values when grew in KM on the 10th day of culture followed by supernatant of 50% digested rotten tomato (DRT) than in  25 and 75% DRT culture. The chemical properties of the culture media such as pH, salinity, dissolved bio-oxygen, electric conductivity and bio-electricity were increased from first day up to 12th day of experiment. Total biomass of spirulina grown in these media had highly significant (P < 0.01) correlation with cell weight (r = 0.825) and chlorophyll a (r = 0.866) of spirulina. The results showed that the growth performances of S. platensis grown in supernatant of 50% DRT was significantly (P < 0.01) higher than that of spirulina grown in supernatant of 25 and 75% DRT. The percentage of crude protein (55.10 ± 0.45 to 59.90 ± 0.33%) of spirulina grown in supernatant of DRT was little bit higher than that of spirulina cultured in KM (58.40 ± 0.38%). But bio-fuel in terms of crude lipids (16.50 ± 0.31%) of spirulina cultured in supernatant of 50% DRT was almost two and half times higher than that of spirulina grown in KM (crude lipids, 6.30 ± 0.21%). Bio-electricity (300 ±10.20 mV) produced in culture of spirulina in supernatant of 50% DRT was higher than  that recorded in KM (240 ±10.20 mV) followed by 75% DRT and other media. Bio-electricity had directly and strongly significant (p < 0.001) correlation with pH (r = 0.812), dissolved bio-oxygen (r = 0.832), salinity (r = 0.788) and electric conductivity (r = 0.856). Therefore, this procedure will produce huge amount of electricity in the world and will make a revolution in this field of bio-electricity production. Whole world will be benefited from the output (results) of this experiment.