Ueno Ryohei, Wada Shun, Urano Naoto
Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo, 108-8477, Japan.
Can J Microbiol. 2008 Jan;54(1):66-70. doi: 10.1139/w07-112.
This study reports on the stability of the cells of a heterotrophic green micro-algal strain Prototheca zopfii RND16 immobilized in polyurethane foam (PUF) cubes during degradation of mixed hydrocarbon substrate, which was composed of n-alkanes and polycyclic aromatic hydrocarbons (PAHs), in 5 successive cycles of repeated batch cultivation at 30 degrees C. Both RND16 cells and mixed hydrocarbon substrate components had been entrapped in PUF cubes through cultivation. PUF-immobilized RND16 degraded n-alkanes almost completely, whereas the strain hardly degraded PAHs in PUFs, rather they accumulated in the matrices. It is noteworthy that this result is strikingly different from that of the free-living cell culture, where RND16 reduced concentrations of both n-alkanes and PAHs. However, PAHs accumulation in the PUFs did not impair the performance of the immobilized alga to utilize n-alkanes. These results suggest that the PUFs harboring RND16 cells could be used repeatedly for selective retrieval of PAHs from oil-polluted waters after preferential biodegradation of n-alkanes by algae.
本研究报告了在30摄氏度下进行的5个连续重复批次培养循环中，固定在聚氨酯泡沫（PUF）立方体中的异养绿色微藻菌株RND16细胞在混合烃底物（由正构烷烃和多环芳烃（PAHs）组成）降解过程中的稳定性。通过培养，RND16细胞和混合烃底物成分都被截留在PUF立方体中。固定在PUF中的RND16几乎完全降解了正构烷烃，而该菌株在PUF中几乎不降解PAHs，相反，它们在基质中积累。值得注意的是，这一结果与自由生活细胞培养的结果显著不同，在自由生活细胞培养中，RND16降低了正构烷烃和PAHs的浓度。然而，PUF中PAHs的积累并未损害固定化藻类利用正构烷烃的性能。这些结果表明，在藻类对正构烷烃进行优先生物降解后，含有RND16细胞的PUF可反复用于从油污染水中选择性回收PAHs。
