%0 Journal Article
%T Bioconversion of D-HPG Using Immobilized Genetic Engineered Strain HC01<br>利用基因工程菌HC01固定化细胞转化生产D-对羟基苯甘氨酸
%A NIU Li-Xi
%A NAN Jing
%A SHI Ya-Wei
%A <br>钮利喜
%A 南晶
%A 石亚伟
%J 微生物学通报
%D 2010
%I 
%X The cells of engineered strain HC01 were immobilized in the form of Ca2+-alginate beads. The conditions for immobilization were investigated. The optimal gel concentration and cell concentration were found to be 2.5% and 0.029 g/mL in the presence of 3% CaCl2. The thermo-stability of immobilized cells was 5°C higher than that of free cells in the same condition. Divalent metal ions, such as Mn2+, Mg2+, Cu2+, Co2+ and Ni2+ did not affect significantly the enzymatic activity of D-hydantoinase (HYD) and N-carbamoylase (CAB) in immobilized cells. By contrast, Mn2+ and Ni2+ could independently enhance the activity of CAB up to 210% and 270% in free cells. The present data showed that the optimal reaction condition of immobilized cells was at pH 7.5 and 40°C as same as that of free cells. The immobilized cells were applied to produce D-p-Hydroxyphenylglycine (D-HPG) directly from the substrate DL-Hydroxyphenyl Hydantoin (DL-HPH) in a batch reactor. Conversion of about 97% was reached after 36-h reaction when the substrate concentration was 30 g/L with the initial pH of 9.0 under the protection of nitrogen gas. The overall yield of D-HPG was 85% with the optical purity of 99.7% after purification.
%K D-Amino acid
%K Engineering strain
%K Immobilization
%K Calcium alginate<br>D-氨基酸
%K 基因工程菌
%K 固定化
%K 海藻酸钙
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=78024727B5F4EF6AA9CA8E605B5FC464&aid=24EBEB66D186F65BB17BD1B551DC3714&yid=140ECF96957D60B2&vid=42425781F0B1C26E&iid=94C357A881DFC066&sid=94383ED6412B441C&eid=7171CFE1768A91C5&journal_id=0253-2654&journal_name=微生物学通报&referenced_num=0&reference_num=0