Henrard Adriano Arruda, da Rosa Gabriel Martins, Moraes Luiza, de Morais Michele Greque, Costa Jorge Alberto Vieira
Laboratory of Biochemical Engineering, College of Chemistry and Food Engineering, Federal University of Rio Grande, Italy Avenue on km 8th, P.O. Box 474, 96203-900 Rio Grande, RS, Brazil.
Laboratory of Microbiology and Biochemical, College of Chemistry and Food Engineering, Federal University of Rio Grande, Italy Avenue on km 8th, P.O. Box 474, 96203-900 Rio Grande, RS, Brazil.
ScientificWorldJournal. 2014;2014:205184. doi: 10.1155/2014/205184. Epub 2014 Dec 15.
The microalgae cultivation can be used as alternative sources of food, in agriculture, residual water treatment, and biofuels production. Semicontinuous cultivation is little studied but is more cost-effective than the discontinuous (batch) cultivation. In the semicontinuous cultivation, the microalga is maintained in better concentration of nutrients and the photoinhibition by excessive cell is reduced. Thus, biomass productivity and biocompounds of interest, such as lipid productivity, may be higher than in batch cultivation. The objective of this study was to examine the influence of blend concentration, medium renewal rate, and concentration of sodium bicarbonate on the growth of Chlorella sp. during semicontinuous cultivation. The cultivation was carried out in Raceway type bioreactors of 6 L, for 40 d at 30°C, 41.6 µmol m(-2) s(-1), and a 12 h light/dark photoperiod. Maximum specific growth rate (0.149 d(-1)) and generating biomass (2.89 g L(-1)) were obtained when the blend concentration was 0.80 g L(-1), the medium renewal rate was 40%, and NaHCO3 was 1.60 g L(-1). The average productivity (0.091 g L(-1) d(-1)) was achieved with 0.8 g L(-1) of blend concentration and NaHCO3 concentration of 1.6 g L(-1), independent of the medium renewal rate.
微藻养殖可作为食物的替代来源，用于农业、废水处理和生物燃料生产。半连续养殖的研究较少，但比间歇（分批）养殖更具成本效益。在半连续养殖中，微藻能保持在更好的营养浓度下，且因细胞过多导致的光抑制会降低。因此，生物质生产力以及诸如脂质生产力等目标生物化合物可能会高于分批养殖。本研究的目的是考察混合浓度、培养基更新率和碳酸氢钠浓度对小球藻在半连续养殖过程中生长的影响。养殖在6升跑道式生物反应器中进行，在30°C、41.6 µmol m(-2) s(-1)以及12小时光照/黑暗光周期条件下持续40天。当混合浓度为0.80 g L(-1)、培养基更新率为40%且NaHCO₃为1.60 g L(-1)时，获得了最大比生长速率（0.149 d(-1)）和生物量产量（2.89 g L(-1)）。当混合浓度为0.8 g L(-1)且NaHCO₃浓度为1.6 g L(-1)时，平均生产力（0.091 g L(-1) d(-1)）得以实现，且与培养基更新率无关。
