Morowvat Mohammad H, Ghasemi Younes
Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, P.O. Box 71345-1583, Shiraz, Iran.
Recent Pat Food Nutr Agric. 2019;10(2):115-123. doi: 10.2174/2212798410666180911100034.
Nowadays, chlorophycean microalgae have attained a broad-spectrum attention as a potential candidate for biomass and bioenergy production. Despite their appreciated benefits, one of major problems is their low biomass and lipid productivity. Here we investigated the heterotrophic culture in shake flasks and stirred tank bioreactor to improve the lipid and biomass production in a naturally isolated strain of Chlorella vulgaris.
A naturally isolated C. vulgaris strain was cultivated in BG-11 medium in shake flask and bioreactor. Its biochemical composition and growth kinetic parameters were investigated.
The biomass productivity was improved (3.68 fold) under heterotrophic culture compared to basal autotrophic culture condition in shake flask experiment. The total lipid content increased to 44% of total Dry Cell Weight (DCW) during heterotrophic growth after 21 days. Moreover, a great Fatty Acid Methyl Esters (FAME) yield was observed under heterotrophic cultivation. Total biomass and lipid content of microalgae in bioreactor experiment increased to 4.95 and 2.18 g L-1 respectively, during 5 days of the experiment compared to its basic autotrophic culture.
The techno-economic aspects of exploiting C. vulgaris as a biodiesel feedstock werealso evaluated. The results imply that heterotrophic cultivation could compensate the low biomass productivity in microalgae for green energy production. Ever growing rates of established patents on application of various genetic and bioengineering-based methods have made it possible to achieve higher lipid contents with reduced total costs for microalgal biodiesel production as well.
如今，绿藻纲微藻作为生物质和生物能源生产的潜在候选者已受到广泛关注。尽管它们有诸多益处，但主要问题之一是其生物量和脂质生产率较低。在此，我们研究了在摇瓶和搅拌罐生物反应器中的异养培养，以提高自然分离的普通小球藻菌株的脂质和生物量产量。
将自然分离的普通小球藻菌株在BG - 11培养基中于摇瓶和生物反应器中培养。研究了其生化组成和生长动力学参数。
在摇瓶实验中，与基础自养培养条件相比，异养培养下生物量生产率提高了（3.68倍）。在21天的异养生长过程中，总脂质含量增加到总干细胞重量（DCW）的44%。此外，在异养培养下观察到了较高的脂肪酸甲酯（FAME）产量。与基础自养培养相比，在生物反应器实验的5天中，微藻的总生物量和脂质含量分别增加到4.95和2.18 g/L。
还评估了将普通小球藻用作生物柴油原料的技术经济方面。结果表明，异养培养可以弥补微藻用于绿色能源生产时生物量生产率较低的问题。基于各种遗传和生物工程方法应用的已授权专利数量不断增加，这也使得在降低微藻生物柴油生产成本的同时实现更高的脂质含量成为可能。
