Trotman Robert J, Camp Carl E, Ben-Bassat Arie, DiCosimo Robert, Huang Lixuan, Crum Grace A, Sariaslani F Sima, Haynie Sharon L
Central Research and Development Department, E. I. du Pont de Nemours and Co., Experimental Station, Wilmington, Delaware 19880-0328, USA.
Biotechnol Prog. 2007 May-Jun;23(3):638-44. doi: 10.1021/bp060379e. Epub 2007 Apr 27.
An Escherichia coli catalyst with tyrosine ammonia lyase activity (TAL) has been stabilized for repeated use in batch conversions of high tyrosine solids to p-hydroxycinnamic acid (pHCA). The TAL biocatalyst was stabilized by controlling the reaction pH to 9.8 +/- 0.1 and immobilizing the cells within a calcium alginate matrix that was cross-linked with glutaraldehyde and polyethyleneimine (GA/PEI). We found a GA range where the bead-encapsulated TAL was not inactivated, and the resulting cross-linking provided the beads with the mechanical stability necessary for repeated use in consecutive batch reactions with catalyst recycle. The GA/PEI calcium alginate TAL catalyst was used in 41 1-L batch reactions where 50 g L(-1) tyrosine was converted to 39 +/- 4 g L(-1) pHCA in each batch. The practical usefulness and ease of this process was demonstrated by scaling up the TAL bead immobilization and using the immobilized TAL catalyst in four 125-L bioconversion reactions to produce over 12 kg of purified pHCA.
一种具有酪氨酸氨裂解酶活性（TAL）的大肠杆菌催化剂已得到稳定化处理，可在将高酪氨酸固体批量转化为对羟基肉桂酸（pHCA）的过程中重复使用。通过将反应pH控制在9.8±0.1，并将细胞固定在与戊二醛和聚乙烯亚胺（GA/PEI）交联的海藻酸钙基质中，TAL生物催化剂得以稳定化。我们发现了一个GA范围，在此范围内，包埋在珠子中的TAL不会失活，并且由此产生的交联为珠子提供了在连续批量反应中与催化剂循环重复使用所需的机械稳定性。GA/PEI海藻酸钙TAL催化剂用于41次1-L批量反应，每次反应中50 g L⁻¹的酪氨酸被转化为39±4 g L⁻¹的pHCA。通过扩大TAL珠子固定化规模并在四个125-L生物转化反应中使用固定化TAL催化剂来生产超过12 kg的纯化pHCA，证明了该过程的实用性和简便性。
