title: Synthesis of β-alanine from L-aspartate using L-aspartate-α-decarboxylase from Corynebacterium glutamicum.
abstract: β-Alanine is mainly produced by chemical methods in current industrial processes. Here, panD from Corynebacterium glutamicum encoding L-aspartate-α-decarboxylase (ADC) was cloned and expressed in Escherichia coli BL21(DE3). ADC C.g catalyzes the α-decarboxylation of L-aspartate to β-alanine. The purified ADC C.g was optimal at 55 °C and pH 6 with excellent stability at 16-37 °C and pH 4-7. A pH-stat directed, fed-batch feeding strategy was developed for enzymatic synthesis of β-alanine to keep the pH value within 6-7.2 and thus attenuate substrate inhibition. A maximum conversion of 97.2 % was obtained with an initial 5 g L-aspartate/l and another three feedings of 0.5 % (w/v) L-aspartate at 8 h intervals. The final β-alanine concentration was 12.85 g/l after 36 h. This is the first study concerning the enzymatic production of β-alanine by using ADC.
authors.affiliation: The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi, 214122, PR, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Shen
authors.forename: Lianzhen
authors.initials: L
authors.lastname: Zhao
authors.forename: Youran
authors.initials: Y
authors.lastname: Li
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
authors.forename: Guiyang
authors.initials: G
authors.lastname: Shi
mesh_terms: D001224:Aspartic Acid / Q000378:metabolism*; D061249:Batch Cell Culture Techniques; D048230:Corynebacterium glutamicum / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D005968:Glutamate Decarboxylase / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D011994:Recombinant Proteins / Q000302:isolation & purification; D012996:Solutions; D013379:Substrate Specificity; D013696:Temperature; D013997:Time Factors; D014462:Ultrafiltration; D015091:beta-Alanine / Q000096:biosynthesis*
chemical_list: D011994:Recombinant Proteins; D012996:Solutions; D015091:beta-Alanine; D001224:Aspartic Acid; C019104:aspartate-alpha-decarboxylase; D005968:Glutamate Decarboxylase