Hejazi M A, de Lamarliere C, Rocha J M S, Vermuë M, Tramper J, Wijffels R H
Food and Bioprocess Engineering Group, Wageningen University, Wageningen, The Netherlands.
Biotechnol Bioeng. 2002 Jul 5;79(1):29-36. doi: 10.1002/bit.10270.
Simultaneous production and selective extraction of beta-carotene from living cells of Dunaliella salina in a two-phase system of aqueous and organic phases has been investigated. Solvents with values of log P(octanol), which denotes hydrophobicity of a compound, ranging from 3 to 9 were used as organic phase. Viability and activity of Dunaliella salina in the presence of organic solvents were checked by microscopic observation and photosynthetic oxygen-production-rate measurements, respectively. Extraction ability of different solvents for both beta-carotene and chlorophyll was determined spectrophotometrically. In addition, beta-carotene contents of the cells growing in the aqueous phase and extracted beta-carotene by the different organic phases were quantified by the same method. Results showed that solvents having log P(octanol) > 6 can be considered biocompatible for this alga. Moreover, pigment extraction ability of a solvent is inversely dependent on its log P(octanol) value. By increasing the degenerative hydrophobicity the extraction ability for both chlorophyll and beta-carotene, decreases. However, this decrease is more profound for chlorophyll. Therefore, selective extraction of beta-carotene becomes feasible. Comparison of the total beta-carotene produced in the presence and in the absence of solvents shows that the presence of a second phase of biocompatible solvents in the culture media may induce the beta-carotene production pathway. The beta-carotene productivity per cell in a two-phase system with dodecane was the highest observed. Extraction ability of the biocompatible solvents dodecane, tetradecan, and hexadecane was similar.
研究了在水相和有机相的两相体系中，从盐生杜氏藻的活细胞中同时生产和选择性提取β-胡萝卜素的方法。使用log P（辛醇）值（表示化合物疏水性）范围为3至9的溶剂作为有机相。分别通过显微镜观察和光合产氧率测量来检查盐生杜氏藻在有机溶剂存在下的活力和活性。用分光光度法测定不同溶剂对β-胡萝卜素和叶绿素的提取能力。此外，用相同方法对在水相中生长的细胞的β-胡萝卜素含量以及不同有机相提取的β-胡萝卜素进行定量。结果表明，log P（辛醇）> 6的溶剂可被认为对这种藻类具有生物相容性。此外，溶剂的色素提取能力与其log P（辛醇）值成反比。随着疏水性的增加，叶绿素和β-胡萝卜素的提取能力均下降。然而，叶绿素的下降更为明显。因此，β-胡萝卜素的选择性提取变得可行。有溶剂存在和无溶剂存在时产生的总β-胡萝卜素的比较表明，培养基中存在生物相容性溶剂的第二相可能会诱导β-胡萝卜素的产生途径。在含有十二烷的两相体系中，每个细胞的β-胡萝卜素生产率是观察到的最高值。生物相容性溶剂十二烷、十四烷和十六烷的提取能力相似。
