摘要
以 1 .4cm和 2 .8cm光径的平板光生物反应器 ,恒定高光强 [2 4 0 0 μE/(m2 ·s) ],通气、无菌高密度连续培养雪地绿藻 (简称雪藻 )。连续采收并补充等量新鲜培养液 ,当藻体生物量(以去灰分干重表示 ,AFDW)达恒态时 ,研究雪藻比生长速率 (SGR)、藻体的生物产量、总脂肪酸 (TFA)和花生四烯酸 (AA)产率。结果表明 ,尽管随着比生长速率增加 ,雪藻高密度连续培养体系的AA/TFA、TFA/AFDW和AA/AFDW三个指标有不同程度的降低 ,但生物产量、总脂肪酸及其花生四烯酸产出都相当高。 2 .8cm光径的平板光生物反应器中 ,雪藻SGR为0 .2d- 1 时 ,每平方米光照面积日获 35 .3gAFDW的高产量 ;SGR 0 .1 35d- 1 时 ,TFA产率最大 ,为7.0g/(m2 ·d) ,此时AA产率也最高 ,达 2 .6g/(m2 ·d)。尽管 1 .4cm光径的反应器的培养体积比前者下降了 5 0 % ,但细胞浓度明显提高 ,单位光照面积的AFDW和TFA最大日产率只下降了37.3%和 1 0 % ,分别为 2 2 .1和 6.3g/(m2 ·d) ,而AA的最大日产率也是 2 .6g/(m2 ·d)。结果还表明 ,氮或磷营养亏缺能明显提高雪藻AA含量的各项指标 ,同时高光强也有利于雪藻累积AA。
Parietochloris incisa is a species of cryophilic green microalgae, which is economically valuable and has a unique ability to accumulate large amount of arachidonic acid. Some physiological profiles like specific growth rate ( SGR ), ash free dry weigh (AFDW), total fatty acids (TFA) and arachidonic acid (AA) in axenic high density culture of this alga were closely studied by using 1.4cm and 2.8cm light path flat photobioreactors. The culture was vigorously aerated and exposed to strong photon flux density [ca.2400μE/(m 2·s)]. Culture was partly harvested daily and the same volume of fresh medium was added into the culture system. Data showed that very high productions of biomass, TFA and AA were observed from the flat photobioreactor systems, although the main profiles (AA/TFA, TFA/AFD and AA/AFDW) decreased in varied content with a similar pattern concomitant with the increase of SGR . Maximal biomass production [AFDW, 35.3g/(m 2·d)] and TFA production [7.0g/(m 2·d)] were obtained in 2.8cm light path photobioreactor when the SGR were at 0.2d -1 and 0.135d -1 . The highest ratio of AA/AFDW was observed when the SGR was at 0.1d -1 , while the AA production [2.6g/(m 2·d)] reached to its maximum when the SGR of the culture was at 0.135d -1 . The maximal TFA production and biomass production in the narrow light path photobioreactor (1.4cm) were 10% and 37.3% less than that of the thick one ( 2.8cm ), though the culture volume was only half. The maximal AA production of two photobioreactors was the same mainly because of the increase of biomass density in narrow light path photobioreactor and partly due to the increase in AA/AFDW profile. The studies also indicated that nitrate or phosphate deficiency accelerated the AA accumulation in the cells, and strong light intensity favored the AA accumulation.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2002年第5期499-508,共10页
Oceanologia Et Limnologia Sinica
基金
国家自然科学基金资助项目 3 95 0 0 1 1 4号3 9970 5 75号
国际科学基金项目A/2 786 1号A/2 786 2号
关键词
雪藻
高密度培养
平板光生物反应器
花生四烯酸
产率
比生长速率
绿藻
Parietochloris incisa , High density culture, Flat photobioreactor, Arachidonic acid, Productivity, Specific growth rate
