Enhanced biomass production and fatty acid accumulation in Scenedesmus sp. LX1 treated with 6-benzylaminopurine

Abstract

Microalgae have great potential for use in the production of valuable products. However, the low productivity of microalgal cultures is a bottleneck that restricts their large-scale application. In this study, the effects of an artificial, synthetic plant growth-promoting substance, 6-benzylaminopurine (6-BA), on the growth characteristics and physiology of Scenedesmus sp. LX1 was investigated. The results showed that 6-BA affected microalgae growth and physiology in a dose-dependent manner; low doses promoted growth while high doses inhibited growth. At the optimum dose (0.1mgL−1), the maximum algal density and the maximum population growth rate were increased by 20% and 52%, respectively, compared with the control. Meanwhile, the yield of fatty acid methyl esters (FAME) also increased, and their compositions were changed, which resulted in an increase in monounsaturated fatty acid content at lower doses. The rates of nitrogen and phosphorus uptake were also enhanced at low doses. The measurement of photosynthetic activity in the microalgae indicated that lower doses of 6-BA enhanced activity by increasing the amounts of chlorophyll, which promoted the growth of microalgae. Metabolic activity analysis showed that lower doses of 6-BA enhanced dehydrogenase activity and ATP accumulation in microalgal cells. Overall, this study shows that 6-BA has a high potential for use in the development efficient microalgal culture systems.