光周期对微绿球藻生长和物质生产的影响

Effects of Photoperiod on the Growth and Substance Production of Nannochloris oculata

为研究光周期对微绿球藻(Nannochloris oculata)生长及物质生产的影响,该文设置了4种长时光周期(光∶暗(h∶h)=24∶0、16∶8、12∶12或8∶16),5种频率光周期(按照光∶暗=16∶8,24 h内分别设置1、4、9、16或25次光暗交替)。结果发现,长时光周期对微绿球藻的生物量干重无显著性影响,而频率光周期对生物量干重影响显著。2种光周期对于微绿球藻的叶绿素a含量有极显著影响,生长速度最快的处理组叶绿素a含量最低。2类光周期对微绿球藻脂质生产均有显著影响,24∶0及16∶8处理组获得较高的脂肪产量,24 h内光暗交替9次处理比交替1次的脂肪产量提高了55.65%。微绿球藻的蛋白质生产受光周期影响不大,但多糖生产受光周期影响显著。微绿球藻的脂肪酸中含量最丰富的是C18∶3(n-3)、C16∶0和C18∶2(n-9),频率光周期对其脂肪酸组成和生物柴油性能影响不显著。

In order to clarify the effect of photoperiod on the growth and biocomponent productions of Nannochloris oculata,four long-term photoperiods(light∶dark=24∶0,16∶8,12∶12,or 8∶16),five frequency photoperiods(light∶dark=16∶8,1,4,9,16,or 25 light-dark alternations within 24 h)were respectively set.The results showed that the long-term photoperiod had little effect while the frequency photoperiod had a significant effect on biomass dry weight of N.oculata.Both long-term and frequency photoperiods significantly affected chlorophyll a content and lipid production.The treatments with the fast growth had the low chlorophyll a content.The long-term photoperiod treatments of 24∶0 and 16∶8 obtained relatively high lipid production.Treatment of 9 light-dark alternations within each 24 h for the frequency photoperiod increased lipid production by 55.65%compared with that of once light-dark alternation.In both long-term and frequency photoperiods,the protein production was not significantly affected but the polysaccharide production was significantly changed.For N.oculata,the most abundant fatty acids were C18∶3(n-3),C16∶0 and C18∶2(n-9),and frequency photoperiod had little effect on both its fatty acid composition and biodiesel performance.