Schenkmayerová Andrea, Bučko Marek, Gemeiner Peter, Treľová Dušana, Lacík Igor, Chorvát Dušan, Ačai Pavel, Polakovič Milan, Lipták Lukáš, Rebroš Martin, Rosenberg Michal, Stefuca Vladimír, Neděla Vilém, Tihlaříková Eva
Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38, Bratislava, Slovakia,
Appl Biochem Biotechnol. 2014 Nov;174(5):1834-49. doi: 10.1007/s12010-014-1174-x. Epub 2014 Aug 23.
Direct comparison of key physical and chemical-engineering properties of two representative matrices for multipurpose immobilisations was performed for the first time. Polyvinyl alcohol lens-shaped particles LentiKats® and polyelectrolyte complex microcapsules were characterised by advanced techniques with respect to the size distribution of the particles, their inner morphology as revealed by fluorescent probe staining, mechanical resistance, size-exclusion properties, determination of effective diffusion coefficient and environmental scanning electron microscope imaging. While spherical polyelectrolyte complex microcapsules composed of a rigid semipermeable membrane and a liquid core are almost uniform in shape and size (diameter of 0.82 mm; RSD = 5.6 %), lens-shaped LentiKats® are characterised by wider size distribution (diameter of 3.65 mm; RSD = 10.3 % and height of 0.341 mm; RSD = 32.3 %) and showed the same porous structure throughout their whole volume at the mesoscopic (micrometre) level. Despite differences in their inner structure and surface properties, the pore diameter of ∼ 2.75 nm for regular polyelectrolyte complex microcapsules and ∼ 1.89 nm for LentiKats® were similar. These results were used for mathematical modelling, which provided the estimates of the effective diffusion coefficient of sucrose. This value was 1.67 × 10(-10) m(2) s(-1) for polyelectrolyte complex microcapsules and 0.36 × 10(-10) m(2) s(-1) for LentiKats®. Recombinant cells Escherichia coli-overexpressing enzyme cyclopentanone monooxygenase were immobilised in polyelectrolyte complex microcapsules and LentiKats® for comparison of their operational stability using model Baeyer-Villiger oxidation of (±)-cis-bicyclo [3.2.0] hept-2-en-6-one to regioisomeric lactones as important chiral synthons for potential pharmaceuticals. Both immobilisation matrices rendered high operational stability for whole-cell biocatalyst with no reduction in the biooxidation rate over 18 repeated reaction cycles.
首次对用于多种固定化的两种代表性基质的关键物理和化学工程性质进行了直接比较。通过先进技术对聚乙烯醇透镜状颗粒LentiKats®和聚电解质复合微胶囊进行了表征，内容涉及颗粒的尺寸分布、荧光探针染色显示的内部形态、机械抗性、尺寸排阻特性、有效扩散系数的测定以及环境扫描电子显微镜成像。由刚性半透膜和液体核心组成的球形聚电解质复合微胶囊在形状和尺寸上几乎是均匀的（直径0.82毫米；相对标准偏差=5.6%），而透镜状的LentiKats®的特点是尺寸分布更宽（直径3.65毫米；相对标准偏差=10.3%，高度0.341毫米；相对标准偏差=32.3%），并且在介观（微米）水平上其整个体积都呈现相同的多孔结构。尽管它们的内部结构和表面性质存在差异，但常规聚电解质复合微胶囊的孔径约为2.75纳米，LentiKats®的孔径约为1.89纳米，二者相似。这些结果被用于数学建模，从而得到了蔗糖有效扩散系数的估计值。聚电解质复合微胶囊的该值为1.67×10⁻¹⁰平方米/秒，LentiKats®的该值为0.36×10⁻¹⁰平方米/秒。将过表达酶环戊酮单加氧酶的重组细胞大肠杆菌固定在聚电解质复合微胶囊和LentiKats®中，以使用(±)-顺式双环[3.2.0]庚-2-烯-6-酮向区域异构体内酯的模型拜耳-维利格氧化反应来比较它们的操作稳定性，这些内酯是潜在药物的重要手性合成子。两种固定化基质都使全细胞生物催化剂具有高操作稳定性，在18个重复反应循环中生物氧化速率没有降低。
