RESUMO
A cyanobacterial strain, Synechococcus sp. NIT18, has been applied to sequester CO2 using sodium carbonate as inorganic carbon source due to its efficiency of CO2 bioconversion and high biomass production. The biomass obtained is used for the extraction of biomolecules - protein, carbohydrate and lipid. The main objective of the study is to maximize the biomass and biomolecules production with CO2 sequestration using cyanobacterial strain cultivated under different concentrations of CO2 (5-20%), pH (7-11) and inoculum size (5-12.5%) within a statistical framework. Maximum sequestration of CO2 and maximum productivities of protein, carbohydrate and lipid are 71.02%, 4.9â¯mg/L/day, 6.7â¯mg/L/day and 1.6â¯mg/L/day respectively, at initial CO2 concentration: 10%, pH: 9 and inoculum size: 12.5%. Since flue gas contains 10-15% CO2 and the present strain is able to sequester CO2 in this range, the strain could be considered as a useful tool for CO2 mitigation for greener world.
Assuntos
Dióxido de Carbono , Sequestro de Carbono , Biomassa , Carbono , Cianobactérias , LipídeosRESUMO
Methylene blue (MB) commonly found in the textile industry effluent has been chosen as a model dye to investigate bioremediation using Bacillus subtilis MTCC 441. Both free cells and calcium alginate immobilized cells have been used to remove MB from the effluent. The operating variables of initial concentration of dye (20-60 mg/L), inoculum size (4-8%) and temperature (25-35 °C) have been varied judiciously during the kinetic study in a batch contactor. A maximum removal of 91.68% is obtained when 20 mg/L MB solution was inoculated with 8% inoculum and cultured for 6 h at 30 °C. Continuous removal of MB has been studied in a fixed bed contactor using immobilized cells as packing materials. Influent concentration (10-30 mg/L) was varied and breakthrough parameters have been determined. With increase in influent concentration from 10 mg/L to 30 mg/L, percentage removal of dye decreases from 72.44% to 49.62%.
