Effective pretreatment of sugarcane bagasse with combination pretreatment and its hydrolyzates as reaction media for the biosynthesis of ethyl (S)-4-chloro-3-hydroxybutanoate by whole cells of E. coli CCZU-K14

He, Yubin; Zhang, Dan‐Ping; Di, Junhua; Wu, Yinqi; Tao, Zheng; Liu, Feng; Zhang, Zhijun; Chong, Gang-Gang; Ding, Yun; Ma, Cuiluan

doi:10.1016/j.biortech.2016.03.150

Cited by 18 publications

(4 citation statements)

References 34 publications

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“…A 250-mL conical flask using 50-mM sodium acetate buffer (pH 5) containing 40 µL tetracycline hydrochloride (25 mg/mL) was used for the enzymatic hydrolysis of the pretreated samples [9]. The stalk samples were added on the basis of a 2.5% solid loading and the enzymatic hydrolysis was then performed at 50 • C and a 150-rpm agitation rate for 72 h. The cellulase obtained from Hunan Youtell Biochemical Co., Ltd. (Hunan province, China) was used for the enzymatic hydrolysis.…”

Section: Enzymatic Hydrolysis Of Stalk Samplesmentioning

confidence: 99%

“…Energy, environmental pollution, public health and food safety are the most important issues for global sustainable development, and production of renewable energy from different organic wastes is attracting increasing attention [1][2][3][4][5][6][7][8]. Lignocellulosic biomass (e.g., corn stalk, wheat straw, and rice straw), which is a sustainable and renewable energy source with reduced net CO 2 emission, has been widely investigated as substrates for ethanol and biogas fermentation [8,9]. In addition to these biomass wastes, energy crops are also potential candidates for biofuel production [10,11].…”

Section: Introductionmentioning

confidence: 99%

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A Two-Step Ferric Chloride and Dilute Alkaline Pretreatment for Enhancing Enzymatic Hydrolysis and Fermentable Sugar Recovery from Miscanthus sinensis

Chen

et al. 2020

Molecules

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A two-step process was proposed to enhance enzymatic hydrolysis of Miscanthus sinensis based on a comparative study of acid/alkaline pretreatments. Ferric chloride pretreatment (FP) effectively removed hemicellulose and recovered soluble sugars, but the enzymatic hydrolysis was not efficient. Dilute alkaline pretreatment (ALP) resulted in much better delignification and stronger morphological changes of the sample, making it more accessible to enzymes. While ALP obtained the highest sugar yield during enzymatic hydrolysis, the soluble sugar recovery from the pretreatment stage was still limited. Furthermore, a two-step ferric chloride and dilute alkaline pretreatment (F-ALP) has been successfully developed by effectively recovering soluble sugars in the first FP step and further removing lignin of the FP sample in the second ALP step to improve its enzymatic hydrolysis. As a result, the two-step process yielded the highest total sugar recovery (418.8 mg/g raw stalk) through the whole process.

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Section: Enzymatic Hydrolysis Of Stalk Samplesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Two-Step Ferric Chloride and Dilute Alkaline Pretreatment for Enhancing Enzymatic Hydrolysis and Fermentable Sugar Recovery from Miscanthus sinensis

Chen

et al. 2020

Molecules

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“…of the product ethyl ( S )-2-hydroxy-4-phenylbutyrate was excellent (>99%). Therefore, using carbonyl reductases to catalyze the asymmetric reduction of prochiral carbonyl compounds is an efficient and useful method for the synthesis of chiral alcohols (He et al 2016 ; Cui et al 2017 ; Qian et al 2014 ).…”

Section: Introductionmentioning

confidence: 99%

Enzymatic characterization of a recombinant carbonyl reductase from Acetobacter sp. CCTCC M209061

Wei

Cui

Zong

et al. 2017

Bioresour. Bioprocess.

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Background Acetobacter sp. CCTCC M209061 could catalyze carbonyl compounds to chiral alcohols following anti-Prelog rule with excellent enantioselectivity. Therefore, the enzymatic characterization of carbonyl reductase (CR) from Acetobacter sp. CCTCC M209061 needs to be investigated.ResultsA CR from Acetobacter sp. CCTCC M209061 (AcCR) was cloned and expressed in E. coli. AcCR was purified and characterized, finding that AcCR as a dual coenzyme-dependent short-chain dehydrogenase/reductase (SDR) was more preferred to NADH for biocatalytic reactions. The AcCR was activated and stable when the temperature was under 35 °C and the pH range was from 6.0 to 8.0 for the reduction of 4′-chloroacetophenone with NADH as coenzyme, and the optimal temperature and pH were 45 °C and 8.5, respectively, for the oxidation reaction of isopropanol with NAD+. The enzyme showed moderate thermostability with half-lives of 25.75 h at 35 °C and 13.93 h at 45 °C, respectively. Moreover, the AcCR has broad substrate specificity to a range of ketones and ketoesters, and could catalyze to produce chiral alcohol with e.e. >99% for the majority of tested substrates following the anti-Prelog rule.ConclusionsThe recombinant AcCR exhibited excellent enantioselectivity, broad substrate spectrum, and highly stereoselective anti-Prelog reduction of prochiral ketones. These results suggest that AcCR is a powerful catalyst for the production of anti-Prelog alcohols.Graphical abstractThe biocatalytic reactions conducted with the recombinant AcCR

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“…Compared with chemical synthesis, biocatalytic asymmetric synthesis of (S)-CHBE from ethyl-4-chloro-3-oxobutyrate (COBE) has attracted more and more attention because it provides eco-friendly reaction conditions, satisfactory selectivity, 100% theoretical yield, and fewer by-products, with simpler and easier operations (3)(4)(5)(6). Therefore, several biocatalytic approaches for the synthesis of (S)-CHBE from COBE employing different carbonyl reductases have been developed (3,(7)(8)(9)(10)(11). However, these methods usually require expensive NADH or NADPH as a cofactor, which represents a great challenge for practical application.…”

mentioning

confidence: 99%

Engineering Streptomyces coelicolor Carbonyl Reductase for Efficient Atorvastatin Precursor Synthesis

Zhang

Kong

et al. 2017

Appl Environ Microbiol

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Streptomyces coelicolor CR1 (ScCR1) has been shown to be a promising biocatalyst for the synthesis of an atorvastatin precursor, ethyl-(S)-4-chloro-3-hydroxybutyrate [(S)-CHBE]. However, limitations of ScCR1 observed for practical application include low activity and poor stability. In this work, protein engineering was employed to improve the catalytic efficiency and stability of ScCR1. First, the crystal structure of ScCR1 complexed with NADH and cosubstrate 2-propanol was solved, and the specific activity of ScCR1 was increased from 38.8 U/mg to 168 U/mg (ScCR1 I158V/P168S ) by structure-guided engineering. Second, directed evolution was performed to improve the stability using ScCR1 I158V/P168S as a template, affording a triple mutant, ScCR1 A60T/I158V/P168S , whose thermostability (T 50 15 , defined as the temperature at which 50% of initial enzyme activity is lost following a heat treatment for 15 min) and substrate tolerance (C 50 15 , defined as the concentration at which 50% of initial enzyme activity is lost following incubation for 15 min) were 6.2°C and 4.7-fold higher than those of the wild-type enzyme. Interestingly, the specific activity of the triple mutant was further increased to 260 U/mg. Protein modeling and docking analysis shed light on the origin of the improved activity and stability. In the asymmetric reduction of ethyl-4-chloro-3-oxobutyrate (COBE) on a 300-ml scale, 100 g/liter COBE could be completely converted by only 2 g/liter of lyophilized ScCR1 A60T/I158V/P168S within 9 h, affording an excellent enantiomeric excess (ee) of Ͼ99% and a space-time yield of 255 g liter Ϫ1 day Ϫ1 . These results suggest high efficiency of the protein engineering strategy and good potential of the resulting variant for efficient synthesis of the atorvastatin precursor.IMPORTANCE Application of the carbonyl reductase ScCR1 in asymmetrically synthesizing (S)-CHBE, a key precursor for the blockbuster drug Lipitor, from COBE has been hindered by its low catalytic activity and poor thermostability and substrate tolerance. In this work, protein engineering was employed to improve the catalytic efficiency and stability of ScCR1. The catalytic efficiency, thermostability, and substrate tolerance of ScCR1 were significantly improved by structure-guided engineering and directed evolution. The engineered ScCR1 may serve as a promising biocatalyst for the biosynthesis of (S)-CHBE, and the protein engineering strategy adopted in this work would serve as a useful approach for future engineering of other reductases toward potential application in organic synthesis.

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Effective pretreatment of sugarcane bagasse with combination pretreatment and its hydrolyzates as reaction media for the biosynthesis of ethyl (S)-4-chloro-3-hydroxybutanoate by whole cells of E. coli CCZU-K14

Cited by 18 publications

References 34 publications

A Two-Step Ferric Chloride and Dilute Alkaline Pretreatment for Enhancing Enzymatic Hydrolysis and Fermentable Sugar Recovery from Miscanthus sinensis

A Two-Step Ferric Chloride and Dilute Alkaline Pretreatment for Enhancing Enzymatic Hydrolysis and Fermentable Sugar Recovery from Miscanthus sinensis

Enzymatic characterization of a recombinant carbonyl reductase from Acetobacter sp. CCTCC M209061

Engineering Streptomyces coelicolor Carbonyl Reductase for Efficient Atorvastatin Precursor Synthesis

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