Department of Biotechnology, Shaheed Benazir Bhutto University, Sheringal, Khyber Pakhtunkhwa, Pakistan.
State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China.
Biotechnol Lett. 2021 Dec;43(12):2259-2272. doi: 10.1007/s10529-021-03194-y. Epub 2021 Oct 19.
This study focuses on dehalogenation of halogenated organic substrate (3-Chloropropiophenone) using both free and hydrogel entrapped microalgae Chlorella emersonii (211.8b) as biocatalyst. We aimed at successful immobilization of C. emersonii (211.8b) cells and to assess their biotransformation efficiency.
Aquasorb (entrapping material in this study) was found to be highly biocompatible with the cellular growth and viability of C. emersonii. A promising number of entrapped cells was achieved in terms of colony-forming units (CFUs = 2.1 × 10) per hydrogel bead with a comparable growth pattern to that of free cells. It was determined that there is no activity of hydrogenase that could transform 1-phenyl-2-propenone into 1-phenyl-1-propanone because after 12 h the ratio between two products (0.36 ± 0.02) remained constant throughout. Furthermore, it was found that the entrapped cells have higher biotransformation of 3-chloropropiophenone to 1-phenyl-1-propanone as compared to free cells at every interval of time. 1-phenyl-2-propenone was excluded from the whole-cell biotransformation as it was also found in the control group (due to spontaneous generation).
Hence, enhanced synthesis of 1-phenyl-1-propanone by entrapped Chlorella (211.8b) can be ascribed to either an enzymatic activity (dehalogenase) or thanks to the antioxidants from 211-8b, especially when they are in immobilized form. The aquasorb based immobilization of microalgae is highly recommended as an effective tool for exploiting microalgal potentials of biocatalysis specifically when free cells activities are seized due to stress.
本研究使用游离和水凝胶包埋微藻小球藻（Chlorella emersonii）（211.8b）作为生物催化剂，专注于卤代有机底物（3-氯丙酰苯）的脱卤作用。我们旨在成功固定 C. emersonii（211.8b）细胞并评估其生物转化效率。
在本研究中，AquaSorb（包埋材料）被发现高度兼容细胞生长和 C. emersonii 的生存力。每个水凝胶珠中实现了大量的包埋细胞，菌落形成单位（CFU）为 2.1×10，与游离细胞的生长模式相当。确定没有氢化酶的活性可以将 1-苯基-2-丙烯酮转化为 1-苯基-1-丙酮，因为在 12 小时后，两种产物之间的比例（0.36±0.02）在整个过程中保持不变。此外，与游离细胞相比，在每个时间间隔，包埋细胞对 3-氯丙酰苯转化为 1-苯基-1-丙酮的生物转化具有更高的活性。1-苯基-2-丙烯酮被排除在整个细胞生物转化之外，因为它也在对照组中发现（由于自发产生）。
因此，与游离小球藻（211.8b）相比，包埋小球藻（211.8b）增强了 1-苯基-1-丙酮的合成，可以归因于酶活性（脱卤酶），也可以归因于 211-8b 的抗氧化剂，尤其是当它们处于固定化形式时。水凝胶包埋微藻是一种非常推荐的方法，因为它是一种有效的工具，可以利用微藻的生物催化潜力，特别是在游离细胞的活性因应激而受到抑制时。
