培养条件对丝状微藻克里藻生长与亚油酸合成的影响

为开发亚油酸生产新资源，对筛选获得的一株丝状微藻克里藻，考察培养基氮浓度、培养基磷浓度、光强、培养温度和环境pH对其生长、氮消耗、油脂含量和油脂脂肪酸组成的影响。结果表明：培养基氮浓度对克里藻生长没有明显影响，但高氮不利于油脂和不饱和脂肪酸的合成；培养基磷浓度过低会抑制细胞生长，过高对细胞有毒害作用；适当提高光强有利于细胞生长，但对细胞内油脂含量影响不大，低光强培养有利于亚油酸等不饱和脂肪酸的合成；培养温度对克里藻生长与油脂积累影响不大，低温培养有利于亚油酸的合成；环境pH对细胞生长、油脂积累和亚油酸合成影响明显，pH 6.0～7.5的弱酸-中性条件下细胞生长最快，油脂含量更高；控制初始氮浓度3～6 mmol/L、磷浓度0.115～0.230 mmol/L、光强100～300μmol/(m²·s)、培养温度15～30℃、环境pH 7.5左右，克里藻细胞可积累42%左右的油脂，油脂中亚油酸含量在65%～75%。综上，丝状微藻克里藻是一种有潜力的亚油酸生产新资源。

Effects of cultivation conditions on growth and synthesis of linoleic acid of filamentous microalgae Klebsormidium sp.

In order to develop new resources for the production of linoleic acid, with a filamentous microalgae Klebsormidium sp. isolated as object, the effect of nitrogen concentration, phosphorus concentration in medium, and light intensity, temperature and environmental pH on the growth, nitrogen consumption, oil content and fatty acid composition of Klebsormidium sp. were investigated. The results showed that nitrogen concentration in the medium did not affect the growth of Klebsormidium sp. , but high nitrogen concentration was detrimental to the synthesis of oil and unsaturated fatty acids. Low phosphorus concentration in the medium inhibited cell growth, while high phosphorus concentration had a toxic effect on cells. Appropriately increasing light intensity was beneficial to cell growth, but had little effect on oil accumulation. More unsaturated fatty acids such as linoleic acid was synthesized under lower light intensity cultivation. Temperature had little effect on the growth and oil accumulation of Klebsormidium sp. , but low temperature was beneficial to the synthesis of linoleic acid. The growth, oil accumulation and linoleic acid content of Klebsormidium sp. were significantly affected by the environmental pH. Cells grew the fastest and had higher oil content in weakly acidic-neutral environments with pH 6.0-7.5. Under the conditions of nitrogen concentration 3-6 mmol/L, phosphorus concentration 0.115-0.230 mmol/L, light intensity 100-300 μmol/(m2·s), temperature 15-30 ℃, environmental pH 7.5, the maximum oil content reached about 42%, of which linoleic acid accounted for 65%-75%. In summary, filamentous microalgae Klebsormidium sp. is a promising new resource for linoleic acid production.