title: Preparation of eutectic substrate mixtures for enzymatic conversion of ATC to L-cysteine at high concentration levels.
abstract: High concentration eutectic substrate solutions for the enzymatic production of L-cysteine were prepared. Eutectic melting of binary mixtures consisting of D,L-2-amino-Δ(2)-thiazoline-4-carboxylic acid (ATC) as a substrate and malonic acid occurred at 39 °C with an ATC mole fraction of 0.5. Formation of eutectic mixtures was confirmed using SEM, SEM-EDS, and XPS surface analyses. Sorbitol, MnSO4, and NaOH were used as supplements for the enzymatic reactions. Strategies for sequential addition of five compounds, including a binary ATC mixture and supplements, during preparation of eutectic substrate solutions were established. Eutectic substrate solutions were stable for 24 h. After 6 h of enzymatic reactions, a 550 mM L-cysteine yield was obtained from a 670 mM eutectic ATC solution.
authors.affiliation: Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-Ro, Seodaemun-Gu, Seoul, 120-749, Republic of Korea.
authors.forename: Sung Hun
authors.initials: SH
authors.lastname: Youn
authors.forename: Hae Woong
authors.initials: HW
authors.lastname: Park
authors.forename: Deokyeong
authors.initials: D
authors.lastname: Choe
authors.forename: Chul Soo
authors.initials: CS
authors.lastname: Shin
mesh_terms: D008239:Lysine / Q000737:chemistry*; D017895:Manganese Compounds / Q000737:chemistry; D008956:Models, Chemical; D012230:Rhizobiaceae / Q000201:enzymology*; D012972:Sodium Hydroxide / Q000737:chemistry; D013012:Sorbitol / Q000737:chemistry; D013431:Sulfates / Q000737:chemistry; D013844:Thiazoles / Q000737:chemistry*
chemical_list: D017895:Manganese Compounds; D013431:Sulfates; D013844:Thiazoles; C015674:2-amino-delta(2)-thiazoline-4-carboxylic acid; D013012:Sorbitol; D012972:Sodium Hydroxide; D008239:Lysine; C039798:manganese sulfate