A cold-adapted leucine dehydrogenase from marine bacterium Alcanivorax dieselolei: Characterization and l-tert-leucine production

作者：Jiang, Wei; Sun, Dongfang; Lu, Jixue; Wang, Yali; Wang, Shizhen; Zhang, Yonghui; Fang, Baishan^*

来源：Engineering in Life Sciences, 2016, 16(3): 283-289.

DOI：10.1002/elsc.201500092

• Alcanivorax dieselolei
• Cold adaptation
• Extreme environments
• LeuDH
• l-tert-leucine enzymatic production

l-tert-leucine, an intermediate in the synthesis of several chiral drugs, is mainly produced by bioconversion, in which leucine dehydrogenase (LeuDH) is the key enzyme. A novel leudh was obtained from the marine bacterium Alcanivorax dieselolei B-5(T) by PCR. The gene encoded a novel cold-adapted LeuDH that showed low similarity (less than 50%) to any known proteins; the highest similarity (42.6%) was found for LeuDH from Bacillus cereus. The cold-adapted LeuDH showed optimal activity at 30? and pH 6.5, and was identified to be extremely cold-adaptive, retaining over 90% activity in the temperature range of 0-37?. The enzyme exhibited better stability in weak alkali environment (pH 6.0-8.5) than Thermoactinomyces intermedius LeuDH. The best substrate concentration was established, and LeuDH conversion rate in catalyzing trimethylpyruvic acid to l-tert-leucine was 54.6%. The cold activity and its ability to produce l-tert-leucine with excellent performance of enantiomers of choice make it a promising biocatalyst for industrial application under extreme conditions.

• 出版日期2016-4
• 单位厦门大学