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Ashok PP, Dasgupta D, Ray A, Suman SK. Challenges and prospects of microbial α-amylases for industrial application: a review. World J Microbiol Biotechnol 2023; 40:44. [PMID: 38114825 DOI: 10.1007/s11274-023-03821-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/27/2023] [Indexed: 12/21/2023]
Abstract
α-Amylases are essential biocatalysts representing a billion-dollar market with significant long-term global demand. They have varied applications ranging from detergent, textile, and food sectors such as bakery to, more recently, biofuel industries. Microbial α-amylases have distinct advantages over their plant and animal counterparts owing to generally good activities and better stability at temperature and pH extremes. With the scope of applications expanding, the need for new and improved α-amylases is ever-growing. However, scaling up microbial α-amylase technology from the laboratory to industry for practical applications is impeded by several issues, ranging from mass transfer limitations, low enzyme yields, and energy-intensive product recovery that adds to high production costs. This review highlights the major challenges and prospects for the production of microbial α-amylases, considering the various avenues of industrial bioprocessing such as culture-independent approaches, nutrient optimization, bioreactor operations with design improvements, and product down-streaming approaches towards developing efficient α-amylases with high activity and recyclability. Since the sequence and structure of the enzyme play a crucial role in modulating its functional properties, we have also tried to analyze the structural composition of microbial α-amylase as a guide to its thermodynamic properties to identify the areas that can be targeted for enhancing the catalytic activity and thermostability of the enzyme through varied immobilization or selective enzyme engineering approaches. Also, the utilization of inexpensive and renewable substrates for enzyme production to isolate α-amylases with non-conventional applications has been briefly discussed.
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Affiliation(s)
- Patel Pratima Ashok
- Biochemistry and Biotechnology Area, Material Resource Efficiency Division, CSIR-Indian Institute of Petroleum, Dehradun, 248005, India
- Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Diptarka Dasgupta
- Biochemistry and Biotechnology Area, Material Resource Efficiency Division, CSIR-Indian Institute of Petroleum, Dehradun, 248005, India.
- Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, 201002, India.
| | - Anjan Ray
- Biochemistry and Biotechnology Area, Material Resource Efficiency Division, CSIR-Indian Institute of Petroleum, Dehradun, 248005, India
- Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Sunil K Suman
- Biochemistry and Biotechnology Area, Material Resource Efficiency Division, CSIR-Indian Institute of Petroleum, Dehradun, 248005, India
- Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, 201002, India
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2
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Zhu M, Zhai W, Song R, Lin L, Wei W, Wei D. Enhanced Thermostability of Geobacillus stearothermophilus α-Amylase by Rational Design of Disulfide Bond and Application in Corn Starch Liquefaction and Bread Quality Improvement. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:18928-18942. [PMID: 38053503 DOI: 10.1021/acs.jafc.3c06761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
α-Amylase (EC 3.2.1.1) from Geobacillus stearothermophilus (generally recognized as safe) exhibited thermal inactivation, hampering its further application in starch-based industries. To address this, we performed structural analyses based on molecular dynamics targeting the flexible regions of α-amylase. Subsequently, we rationally designed a thermostable mutant, AmyS1, by introducing disulfide bonds to stabilize the flexible regions. AmyS1 showed excellent thermostability without any stability-activity trade-off, giving a 40-fold longer T1/2 (1359 min) at 90 °C. Thermostability mechanism analysis revealed that the introduction of disulfide bonds in AmyS1 refined weak spots and reconfigured the protein's force network. Moreover, AmyS1 exhibited improved pH compatibility and enhanced corn starch liquefaction at 100 °C with a 5.1-fold increased product concentration. Baking tests confirmed that AmyS1 enhanced bread quality and extended the shelf life. Therefore, mutant AmyS1 is a robust candidate for the starch-based industry.
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Affiliation(s)
- Mengyu Zhu
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China
| | - Wenxin Zhai
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China
| | - Runfei Song
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China
| | - Lin Lin
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China
- Research Laboratory for Functional Nanomaterial, National Engineering Research Center for Nanotechnology, Shanghai 200241, China
| | - Wei Wei
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China
| | - Dongzhi Wei
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China
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3
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Yao D, Han X, Gao H, Wang B, Fang Z, Li H, Fang W, Xiao Y. Enhanced extracellular production of raw starch-degrading α-amylase in Bacillus subtilis through expression regulatory element modification and fermentation optimization. Microb Cell Fact 2023; 22:118. [PMID: 37381017 DOI: 10.1186/s12934-023-02116-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/17/2023] [Indexed: 06/30/2023] Open
Abstract
BACKGROUND Raw starch-degrading α-amylase (RSDA) can hydrolyze raw starch at moderate temperatures, thus contributing to savings in starch processing costs. However, the low production level of RSDA limits its industrial application. Therefore, improving the extracellular expression of RSDA in Bacillus subtilis, a commonly used industrial expression host, has great value. RESULTS In this study, the extracellular production level of Pontibacillus sp. ZY raw starch-degrading α-amylase (AmyZ1) in B. subtilis was enhanced by expression regulatory element modification and fermentation optimization. As an important regulatory element of gene expression, the promoter, signal peptide, and ribosome binding site (RBS) sequences upstream of the amyZ1 gene were sequentially optimized. Initially, based on five single promoters, the dual-promoter Pveg-PylB was constructed by tandem promoter engineering. Afterward, the optimal signal peptide SPNucB was obtained by screening 173 B. subtilis signal peptides. Then, the RBS sequence was optimized using the RBS Calculator to obtain the optimal RBS1. The resulting recombinant strain WBZ-VY-B-R1 showed an extracellular AmyZ1 activity of 4824.2 and 41251.3 U/mL during shake-flask cultivation and 3-L fermenter fermentation, which were 2.6- and 2.5-fold greater than those of the original strain WBZ-Y, respectively. Finally, the extracellular AmyZ1 activity of WBZ-VY-B-R1 was increased to 5733.5 U/mL in shake flask by optimizing the type and concentration of carbon source, nitrogen source, and metal ions in the fermentation medium. On this basis, its extracellular AmyZ1 activity was increased to 49082.1 U/mL in 3-L fermenter by optimizing the basic medium components as well as the ratio of carbon and nitrogen sources in the feed solution. This is the highest production level reported to date for recombinant RSDA production. CONCLUSIONS This study represents a report on the extracellular production of AmyZ1 using B. subtilis as a host strain, and achieved the current highest expression level. The results of this study will lay a foundation for the industrial application of RSDA. In addition, the strategies employed here also provide a promising way for improving other protein production in B. subtilis.
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Affiliation(s)
- Dongbang Yao
- School of Life Sciences, Anhui University, Hefei, 230601, China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601, China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601, China
- AHU Green Industry Innovation Research Institute, Hefei, 230088, China
| | - Xudong Han
- School of Life Sciences, Anhui University, Hefei, 230601, China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601, China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601, China
- AHU Green Industry Innovation Research Institute, Hefei, 230088, China
| | - Huanhuan Gao
- School of Life Sciences, Anhui University, Hefei, 230601, China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601, China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601, China
- AHU Green Industry Innovation Research Institute, Hefei, 230088, China
| | - Bin Wang
- School of Life Sciences, Anhui University, Hefei, 230601, China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601, China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601, China
- AHU Green Industry Innovation Research Institute, Hefei, 230088, China
| | - Zemin Fang
- School of Life Sciences, Anhui University, Hefei, 230601, China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601, China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601, China
- AHU Green Industry Innovation Research Institute, Hefei, 230088, China
| | - He Li
- School of Life Sciences, Anhui University, Hefei, 230601, China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601, China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601, China
- AHU Green Industry Innovation Research Institute, Hefei, 230088, China
| | - Wei Fang
- School of Life Sciences, Anhui University, Hefei, 230601, China.
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601, China.
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601, China.
- AHU Green Industry Innovation Research Institute, Hefei, 230088, China.
| | - Yazhong Xiao
- School of Life Sciences, Anhui University, Hefei, 230601, China.
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601, China.
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601, China.
- AHU Green Industry Innovation Research Institute, Hefei, 230088, China.
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Liao M, Dong R, Li L, Liu X, Wang Y, Bai Y, Luo H, Yao B, Huang H, Tu T. High Production of Maltooligosaccharides in the Starch Liquefaction Process: A Study on the Hyperthermophilic Mechanism of α-Amylase. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:6480-6489. [PMID: 36959740 DOI: 10.1021/acs.jafc.3c00665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The efficient production of high-value-added bioproducts from starchy substances requires α-amylases with hyperthermophilic properties for industrial starch liquefaction. In this study, two hyperthermophilic α-amylases with significant differences in thermostability, PfAmy and TeAmy, were comparatively studied through structural analysis, domain swapping, and site-directed mutagenesis, finding that three residues, His152, Cys166, and His168, located in domain B were the main contributors to hyperthermostability. The effects of these three residues were strongly synergistic, causing the optimum temperature for the mutant K152H/A166C/E168H of TeAmy to shift to 95-100 °C and stabilize at 90 °C without Ca2+. Compared to PfAmy and TeAmy, the mutant K152H/A166C/E168H, respectively, exhibited 1.7- and 2.5-times higher starch hydrolysis activity at 105 °C and pH 5.5 (10411 ± 70 U/mg) and released 1.1- and 1.7-times more maltooligosaccharides from 1% starch. This work has interpreted the hyperthermophilic mechanism of α-amylase and thereby providing a potential candidate for the efficient industrial conversion of starch to bioproducts.
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Affiliation(s)
- Min Liao
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Ruyue Dong
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Lanxue Li
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiaoqing Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yaru Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yingguo Bai
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huiying Luo
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Bin Yao
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huoqing Huang
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Tao Tu
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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Ahmad A, Rahamtullah, Mishra R. Structural and functional adaptation in extremophilic microbial α-amylases. Biophys Rev 2022; 14:499-515. [PMID: 35528036 PMCID: PMC9043155 DOI: 10.1007/s12551-022-00931-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 01/12/2022] [Indexed: 01/26/2023] Open
Abstract
Maintaining stable native conformation of a protein under a given ecological condition is the prerequisite for survival of organisms. Extremophilic bacteria and archaea have evolved to adapt under extreme conditions of temperature, pH, salt, and pressure. Molecular adaptations of proteins under these conditions are essential for their survival. These organisms have the capability to maintain stable, native conformations of proteins under extreme conditions. The enzymes produced by the extremophiles are also known as extremozyme, which are used in several industries. Stability and functionality of extremozymes under varying temperature, pH, and solvent conditions are the most desirable requirement of industry. α-Amylase is one of the most important enzymes used in food, pharmaceutical, textile, and detergent industries. This enzyme is produced by diverse microorganisms including various extremophiles. Therefore, understanding its stability is important from fundamental as well as an applied point of view. Each class of extremophiles has a distinctive set of dominant non-covalent interactions which are important for their stability. Static information obtained by comparative analysis of amino acid sequence and atomic resolution structure provides information on the prevalence of particular amino acids or a group of non-covalent interactions. Protein folding studies give the information about thermodynamic and kinetic stability in order to understand dynamic aspect of molecular adaptations. In this review, we have summarized information on amino acid sequence, structure, stability, and adaptability of α-amylases from different classes of extremophiles.
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Affiliation(s)
- Aziz Ahmad
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110,067 India
| | - Rahamtullah
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110,067 India
| | - Rajesh Mishra
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110,067 India
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6
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Zhang L, Zhong L, Wang J, Zhao Y, Zhang Y, Zheng Y, Dong W, Ye X, Huang Y, Li Z, Cui Z. Efficient hydrolysis of raw starch by a maltohexaose-forming α-amylase from Corallococcus sp. EGB. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.112361] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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7
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Ni G, Zhong L, Xia C, Zhang L, Dai L, Chen R, Zhao Y, Wang F. Phenylalanine 314 is essential for the activity of maltogenic amylase from Corallococcus sp. EGB. Biotechnol Appl Biochem 2021; 69:2240-2248. [PMID: 34775631 DOI: 10.1002/bab.2282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 11/01/2021] [Indexed: 11/06/2022]
Abstract
Maltogenic amylase CoMA from Corallococcus sp. strain EGB catalyzes the hydrolysis and transglycosylation of maltooligosaccharides and soluble starch into maltose, the sole hydrolysate. This process yields pure maltose with potentially wide applications. Here, we identified and evaluated the role of phenylalanine 314 (F314), a key amino acid located near the active center, in the catalytic activities of the CoMA. Site-directed mutagenesis analysis showed that the activity of a F314L mutant on potato starch substrate decreased to 26% of that of wild-type protein. Compared with the wild-type, F314L exhibited similar substrate specificity, hydrolysis pattern, pH, and temperature requirements. Circular dichroism spectrum data showed that the F314L mutation did not affect the structure of the folded protein. In addition, kinetic analysis demonstrated that F314L exhibited an increased Km value with lower substrate affinity. Homology modeling showed that the benzene ring structure of F314L was involved in π-π conjugation, which might potentially affect the affinity of CoMA toward starch. Taken together, these data demonstrated that F314 is essential for the hydrolytic activity of the CoMA from Corallococcus sp. strain EGB.
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Affiliation(s)
- Guorong Ni
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China
| | - Lingli Zhong
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Science, Nanjing Agricultural University, Nanjing, China
| | - Chengyao Xia
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Science, Nanjing Agricultural University, Nanjing, China
| | - Lixia Zhang
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China
| | - Longhua Dai
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China
| | - Ruyi Chen
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China
| | - Yuqiang Zhao
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Science, Nanjing Agricultural University, Nanjing, China.,Institute of Botany Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing, China
| | - Fei Wang
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China
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Yao D, Zhang K, Zhu X, Su L, Wu J. Enhanced extracellular α-amylase production in Brevibacillus choshinensis by optimizing extracellular degradation and folding environment. J Ind Microbiol Biotechnol 2021; 49:6380490. [PMID: 34601573 PMCID: PMC9113144 DOI: 10.1093/jimb/kuab061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 08/22/2021] [Indexed: 11/14/2022]
Abstract
A strategy for optimizing the extracellular degradation and folding environment of Brevibacillus choshinensis has been used to enhance the extracellular production of recombinant α-amylase. First, a gene (bcp) encoding an extracellular protease and another encoding an extracellular chaperone (prsC) were identified in the genome of B. choshinensis HPD31-SP3. Then, the effect of extracellular protein degradation on recombinant α-amylase production was investigated by establishing a CRISPR/Cas9n system to knock out bcp. The effect of extracellular folding capacity was investigated separately by coexpressing extracellular chaperones genes from different sources (prsA, prsC, prsL, prsQ) in B. choshinensis. The final recombinant strain (BCPPSQ), which coexpressed prsQ in a genetic background lacking bcp, produced an extracellular α-amylase activity of 6940.9 U/mL during shake-flask cultivation. This was 2.1-fold greater than that of the original strain BCWPS (3367.9 U/mL). Cultivation of BCPPSQ in a 3-L fermenter produced an extracellular α-amylase activity of 17 925.6 U/mL at 72 h, which was 7.6-fold greater than that of BCWPS (2358.1 U/mL). This strategy demonstrates its great potential in enhancing extracellular α-amylase production in B. choshinensis. What's more, this study provides a strategic reference for improving the extracellular production of other recombinant proteins in B. choshinensis.
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Affiliation(s)
- Dongbang Yao
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Kang Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Xuyang Zhu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Lingqia Su
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Jing Wu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
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9
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Lim SJ, Oslan SN. Native to designed: microbial -amylases for industrial applications. PeerJ 2021; 9:e11315. [PMID: 34046253 PMCID: PMC8139272 DOI: 10.7717/peerj.11315] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 03/30/2021] [Indexed: 12/31/2022] Open
Abstract
Background -amylases catalyze the endo-hydrolysis of -1,4-D-glycosidic bonds in starch into smaller moieties. While industrial processes are usually performed at harsh conditions, -amylases from mainly the bacteria, fungi and yeasts are preferred for their stabilities (thermal, pH and oxidative) and specificities (substrate and product). Microbial -amylases can be purified and characterized for industrial applications. While exploring novel enzymes with these properties in the nature is time-costly, the advancements in protein engineering techniques including rational design, directed evolution and others have privileged their modifications to exhibit industrially ideal traits. However, the commentary on the strategies and preferably mutated residues are lacking, hindering the design of new mutants especially for enhanced substrate specificity and oxidative stability. Thus, our review ensures wider accessibility of the previously reported experimental findings to facilitate the future engineering work. Survey methodology and objectives A traditional review approach was taken to focus on the engineering of microbial -amylases to enhance industrially favoured characteristics. The action mechanisms of - and -amylases were compared to avoid any bias in the research background. This review aimed to discuss the advances in modifying microbial -amylases via protein engineering to achieve longer half-life in high temperature, improved resistance (acidic, alkaline and oxidative) and enhanced specificities (substrate and product). Captivating results were discussed in depth, including the extended half-life at 100C, pH 3.5 and 10, 1.8 M hydrogen peroxide as well as enhanced substrate (65.3%) and product (42.4%) specificities. These shed light to the future microbial -amylase engineering in achieving paramount biochemical traits ameliorations to apt in the industries. Conclusions Microbial -amylases can be tailored for specific industrial applications through protein engineering (rational design and directed evolution). While the critical mutation points are dependent on respective enzymes, formation of disulfide bridge between cysteine residues after mutations is crucial for elevated thermostability. Amino acids conversion to basic residues was reported for enhanced acidic resistance while hydrophobic interaction resulted from mutated hydrophobic residues in carbohydrate-binding module or surface-binding sites is pivotal for improved substrate specificity. Substitution of oxidation-prone methionine residues with non-polar residues increases the enzyme oxidative stability. Hence, this review provides conceptual advances for the future microbial -amylases designs to exhibit industrially significant characteristics. However, more attention is needed to enhance substrate specificity and oxidative stability since they are least reported.
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Affiliation(s)
- Si Jie Lim
- Enzyme Technology Laboratory, VacBio 5, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.,Enzyme and Microbial Technology (EMTech) Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Siti Nurbaya Oslan
- Enzyme Technology Laboratory, VacBio 5, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.,Enzyme and Microbial Technology (EMTech) Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.,Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
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10
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Madhavan A, Arun KB, Binod P, Sirohi R, Tarafdar A, Reshmy R, Kumar Awasthi M, Sindhu R. Design of novel enzyme biocatalysts for industrial bioprocess: Harnessing the power of protein engineering, high throughput screening and synthetic biology. BIORESOURCE TECHNOLOGY 2021; 325:124617. [PMID: 33450638 DOI: 10.1016/j.biortech.2020.124617] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/19/2020] [Accepted: 12/22/2020] [Indexed: 05/13/2023]
Abstract
Biocatalysts have wider applications in various industries. Biocatalysts are generating bigger attention among researchers due to their unique catalytic properties like activity, specificity and stability. However the industrial use of many enzymes is hindered by low catalytic efficiency and stability during industrial processes. Properties of enzymes can be altered by protein engineering. Protein engineers are increasingly study the structure-function characteristics, engineering attributes, design of computational tools for enzyme engineering, and functional screening processes to improve the design and applications of enzymes. The potent and innovative techniques of enzyme engineering deliver outstanding opportunities for tailoring industrially important enzymes for the versatile production of biochemicals. An overview of the current trends in enzyme engineering is explored with important representative examples.
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Affiliation(s)
- Aravind Madhavan
- Rajiv Gandhi Centre for Biotechnology, Trivandrum 695 014, India
| | - K B Arun
- Rajiv Gandhi Centre for Biotechnology, Trivandrum 695 014, India
| | - Parameswaran Binod
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum 695 019, India
| | - Ranjna Sirohi
- The Center for Energy and Environmental Sustainability, Lucknow 226 010, Uttar Pradesh, India
| | - Ayon Tarafdar
- Division of Livestock Production and Management, ICAR - Indian Veterinary Research Institute, Izatnagar, Bareilly 243 122, Uttar Pradesh, India
| | - R Reshmy
- Post Graduate and Research Department of Chemistry, Bishop Moore College, Mavelikara 690 110, Kerala, India
| | - Mukesh Kumar Awasthi
- College of Natural Resources and Environment, North West A & F University, Yangling, Shaanxi 712 100, China
| | - Raveendran Sindhu
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum 695 019, India.
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11
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Paul JS, Gupta N, Beliya E, Tiwari S, Jadhav SK. Aspects and Recent Trends in Microbial α-Amylase: a Review. Appl Biochem Biotechnol 2021; 193:2649-2698. [PMID: 33715051 DOI: 10.1007/s12010-021-03546-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
α-Amylases are the oldest and versatile starch hydrolysing enzymes which can replace chemical hydrolysis of starch in industries. It cleaves the α-(1,4)-D-glucosidic linkage of starch and other related polysaccharides to yield simple sugars like glucose, maltose and limit dextrin. α-Amylase covers about 30% shares of the total enzyme market. On account of their superior features, α-amylase is the most widely used among all the existing amylases for hydrolysis of polysaccharides. Endo-acting α-amylase of glycoside hydrolase family 13 is an extensively used biocatalyst and has various biotechnological applications like in starch processing, detergent, textile, paper and pharmaceutical industries. Apart from these, it has some novel applications including polymeric material for drug delivery, bioremediating agent, biodemulsifier and biofilm inhibitor. The present review will accomplish the research gap by providing the unexplored aspects of microbial α-amylase. It will allow the readers to know about the works that have already been done and the latest trends in this field. The manuscript has covered the latest immobilization techniques and the site-directed mutagenesis approaches which are readily being performed to confer the desirable property in wild-type α-amylases. Furthermore, it will state the inadequacies and the numerous obstacles coming in the way of its production during upstream and downstream steps and will also suggest some measures to obtain stable and industrial-grade α-amylase.
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Affiliation(s)
- Jai Shankar Paul
- School of Studies in Biotechnology, Pt. Ravishankar Shukla University, Raipur, CG, 492010, India
| | - Nisha Gupta
- School of Studies in Biotechnology, Pt. Ravishankar Shukla University, Raipur, CG, 492010, India
| | - Esmil Beliya
- School of Studies in Biotechnology, Pt. Ravishankar Shukla University, Raipur, CG, 492010, India.,Department of Botany, Govt. College, Bichhua, Chhindwara, MP, 480111, India
| | - Shubhra Tiwari
- School of Studies in Biotechnology, Pt. Ravishankar Shukla University, Raipur, CG, 492010, India
| | - Shailesh Kumar Jadhav
- School of Studies in Biotechnology, Pt. Ravishankar Shukla University, Raipur, CG, 492010, India.
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12
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A novel metagenome-derived thermostable and poultry feed compatible α-amylase with enhanced biodegradation properties. Int J Biol Macromol 2020; 164:2124-2133. [DOI: 10.1016/j.ijbiomac.2020.08.064] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/06/2020] [Accepted: 08/07/2020] [Indexed: 12/28/2022]
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13
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Ojha SK, Singh PK, Mishra S, Pattnaik R, Dixit S, Verma SK. Response surface methodology based optimization and scale-up production of amylase from a novel bacterial strain, Bacillus aryabhattai KIIT BE-1. ACTA ACUST UNITED AC 2020; 27:e00506. [PMID: 32742945 PMCID: PMC7388185 DOI: 10.1016/j.btre.2020.e00506] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/16/2020] [Accepted: 07/13/2020] [Indexed: 12/31/2022]
Abstract
A novel strain KIIT BE-1 isolated from a specialized environment, screened through starch iodine test from a set of eighty-five biodigestate isolates, produced amylase maximally when cultured for 48 h at 37 °C. The molecular and biochemical characterization confirmed it as a strain of Bacillus aryabhattai. It exhibited optimal amylase activity (3.20 U/ml) at 36 h post incubation with a media combination of starch and yeast extract for C-N source respectively. Statistical optimisation by response surface modeling showed R2 values of 0.9645 for biomass and 0.9831 for amylase activity, suggesting the significance of the model. The optimised medium (10.25 % starch, 5.0 % peptone, 5.18 % yeast extract, pH 7.3) enhanced the enzyme activity to 4.16 U/ml (1.39-fold) from 3.20 U/ml of un-optimised medium. Further, the biomass yield and the enzymatic activity in optimized medium and process conditions increased by 1.14 and 1.21 folds subjected to a 5 l scaled-up operation in a lab-scale bioreactor.
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Affiliation(s)
- Sanjay Kumar Ojha
- School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT) Deemed-to-be-University, Bhubaneswar, 751 024, India.,Pandorum Technologies Pvt. Ltd., Bangalore Bioinnovation Centre, Helix Biotech Park, Electronic City Phase 1, Bengaluru, 560 100, India
| | - Puneet Kumar Singh
- School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT) Deemed-to-be-University, Bhubaneswar, 751 024, India
| | - Snehasish Mishra
- School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT) Deemed-to-be-University, Bhubaneswar, 751 024, India
| | - Ritesh Pattnaik
- School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT) Deemed-to-be-University, Bhubaneswar, 751 024, India
| | - Shubha Dixit
- School of Pharmacy, Lloyd Institute of Management and Technology, PlotNo.11, Knowledge Park II, Greater Noida, 201310, India
| | - Suresh K Verma
- School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT) Deemed-to-be-University, Bhubaneswar, 751 024, India
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14
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Pinto ÉSM, Dorn M, Feltes BC. The tale of a versatile enzyme: Alpha-amylase evolution, structure, and potential biotechnological applications for the bioremediation of n-alkanes. CHEMOSPHERE 2020; 250:126202. [PMID: 32092569 DOI: 10.1016/j.chemosphere.2020.126202] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 01/10/2020] [Accepted: 02/12/2020] [Indexed: 06/10/2023]
Abstract
As the primary source of a wide range of industrial products, the study of petroleum-derived compounds is of pivotal importance. However, the process of oil extraction and refinement is among the most environmentally hazardous practices, impacting almost all levels of the ecological chain. So far, the most appropriate strategy to overcome such an issue is through bioremediation, which revolves around the employment of different microorganisms to degrade hazardous compounds, generating less environmental impact and lower monetary costs. In this sense, a myriad of organisms and enzymes are considered possible candidates for the bioremediation process. Amidst the potential candidates is α-amylase, an evolutionary conserved starch-degrading enzyme. Notably, α-amylase was not only seen to degrade n-alkanes, a subclass of alkanes considered the most abundant petroleum-derived compounds but also low-density polyethylene, a dangerous pollutant produced from petroleum. Thus, due to its high conservation in both eukaryotic and prokaryotic lineages, in addition to the capability to degrade different types of hazardous compounds, the study of α-amylase becomes a rising interest. Nevertheless, there are no studies that review all biotechnological applications of α-amylase for bioremediation. In this work, we critically review the potential biotechnological applications of α-amylase, focusing on the biodegradation of petroleum-derived compounds. Evolutionary aspects are discussed, as well for all structural information and all features that could impact on the employment of this protein in the biotechnological industry, such as pH, temperature, and medium conditions. New perspectives and critical assessments are conducted regarding the application of α-amylase in the bioremediation of n-alkanes.
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Affiliation(s)
- Éderson Sales Moreira Pinto
- Laboratory of Structural Bioinformatics and Computational Biology, Center for Biotechnology, Federal University of Rio Grande do Sul, Brazil
| | - Márcio Dorn
- Laboratory of Structural Bioinformatics and Computational Biology, Institute of Informatics, Federal University of Rio Grande do Sul, Brazil; Laboratory of Structural Bioinformatics and Computational Biology, Center for Biotechnology, Federal University of Rio Grande do Sul, Brazil
| | - Bruno César Feltes
- Laboratory of Structural Bioinformatics and Computational Biology, Institute of Informatics, Federal University of Rio Grande do Sul, Brazil.
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15
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Torktaz I, Hemmat J, Karkhane AA, Rigi G, Rostami A, Khezri J, Behroozi R. Molecular Engineering of the Geobacillus stearothermophilus α-Amylase and Cel5E from Chlostridium thermocellim; In Silico Approach. IRANIAN JOURNAL OF BIOTECHNOLOGY 2019; 16:e1284. [PMID: 31457020 PMCID: PMC6697822 DOI: 10.15171/ijb.1284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 10/24/2017] [Accepted: 10/25/2017] [Indexed: 11/23/2022]
Abstract
Background Considering natural thermal stability, Geobacillus stearothermophilus amylase and Cel5E from Clostridium thermocellum are good candidates for industrial applications. To be compatible with the industrial applications, this enzyme should be stable in the high temperatures, so any improvement in their thermal stability is valuable. Objectives Using in silico approach and identifying point mutations in the structure amylase of G. stearothermophilus and Cel5E from C. termocellum we tried to increase thermal stability of the enzymes along with their catalytic activity to reach a new industrial amylase with higher thermostability and an improved function. Materials and Methods In this study we predicted the 3D structure of the enzymes, then simulated the molecular docking study using MolDock, PLANTS, and Lamarkian genetic algorithm as scoring functions for the docking and in silico engineering of the protein aiming to increase the thermal stability and catalytic activity. Results A series of thermal stability increasing point mutations were exerted around the active site of the enzyme, then by docking procedure, the binding affinity was measured and finally a list of mutations which theoretically improved the increased thermal stability as well as catalytic activity were proposed. Conclusions Based on the in silico results obtained the modified enzymes seems to be suitable candidates for considering in both laboratory and industrial scales.
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Affiliation(s)
- Ibrahim Torktaz
- National Institute of Genetic Engineering and Biotechnology, Tehran, Iran.,Biotechnology Department. Iranian Research Organization for Science and Technology (IROST) Tehran-Iran
| | - Jafar Hemmat
- Biotechnology Department. Iranian Research Organization for Science and Technology (IROST) Tehran-Iran
| | | | - Garshasb Rigi
- Department of Genetics, Faculty of Basic Science, University of Shahrekord, Shahrekord, Iran
| | - Amin Rostami
- Department of Basic Sciences, Faculty of Paramedical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Jafar Khezri
- National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Reza Behroozi
- National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
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16
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Low molecular weight alkaline thermostable α-amylase from Geobacillus sp. nov. Heliyon 2019; 5:e02171. [PMID: 31388592 PMCID: PMC6667821 DOI: 10.1016/j.heliyon.2019.e02171] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 01/30/2019] [Accepted: 07/24/2019] [Indexed: 01/11/2023] Open
Abstract
Industrial demands for enzymes that are stable in a broad range of conditions are increasing. Such enzymes, one of which is α-amylase, could be produced by extremophiles. This study reports a thermostable α-amylase produced by a newly isolated Geobacillus sp. nov. from a geothermal area. The phylogenetic analysis of the 16S rRNA gene showed that the isolate formed a separate branch with 95% homology to Geobacillus sp. After precipitation using ammonium sulphate followed by ion-exchange chromatography, the enzyme produced a specific activity of 25.1 (U/mg) with a purity of 6.5-fold of the crude extract. The molecular weight of the enzyme was approximately 12.2 kDa. The optimum activity was observed at 75 °C and pH 8. The activity increased in the presence of Ba2+ and Fe2+ but decreased in the presence of K+ and Mg2+. Ca2+ and Mn2+ increased the activity slightly. The activity completely diminished with the addition of Cu2+. EDTA and PMSF also sharply reduced enzyme activity. Although the stability was moderate, the low molecular weight could be an important feature for its future applications.
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17
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Yao D, Su L, Li N, Wu J. Enhanced extracellular expression of Bacillus stearothermophilus α-amylase in Bacillus subtilis through signal peptide optimization, chaperone overexpression and α-amylase mutant selection. Microb Cell Fact 2019; 18:69. [PMID: 30971250 PMCID: PMC6458788 DOI: 10.1186/s12934-019-1119-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 04/03/2019] [Indexed: 01/14/2023] Open
Abstract
Background Our laboratory has constructed a Bacillus stearothermophilus α-amylase (AmyS) derivative with excellent enzymatic properties. Bacillus subtilis is generally regarded as safe and has excellent protein secretory capability, but heterologous extracellular production level of B. stearothermophilus α-amylase in B. subtilis is very low. Results In this study, the extracellular production level of B. stearothermophilus α-amylase in B. subtilis was enhanced by signal peptide optimization, chaperone overexpression and α-amylase mutant selection. The α-amylase optimal signal peptide (SPYojL) was obtained by screening 173 B. subtilis signal peptides. Although the extracellular α-amylase activity that was produced by the resulting recombinant strain was 3.5-fold greater than that of the control, significant quantities of inclusion bodies were detected. Overexpressing intracellular molecular chaperones significantly reduced inclusion body formation and further increased α-amylase activity. Error-prone PCR produced an amylase mutant K82E/S405R (AmySA) with enzymatic activity superior to that of AmyS. Expression of the amySA gene with the SPYojL while overexpressing molecular chaperones resulted in a 7.1-fold improvement in α-amylase activity. When the final expression strain (WHS11YSA) was cultivated in a 3-L fermenter for 92 h, the α-amylase activity of the culture supernatant was 9201.1 U mL−1, which is the highest level that has been reported to date. Conclusions This is the first report that describes an improvement of B. stearothermophilus α-amylase extracellular production levels in B. subtilis using these strategies, and this represents the highest extracellular production level ever reported for α-amylase from B. stearothermophilus in B. subtilis. This high-level production provides a basis for enhanced industrial production of α-amylase. These extracellular production level improvement approaches are also expected to be valuable in the expression of other enzymes in B. subtilis. Electronic supplementary material The online version of this article (10.1186/s12934-019-1119-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Dongbang Yao
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Lingqia Su
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Na Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Jing Wu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China. .,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China. .,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.
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18
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Wang YC, Zhao N, Ma JW, Liu J, Yan QJ, Jiang ZQ. High-level expression of a novel α-amylase from Thermomyces dupontii in Pichia pastoris and its application in maltose syrup production. Int J Biol Macromol 2019; 127:683-692. [DOI: 10.1016/j.ijbiomac.2019.01.162] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 01/28/2019] [Accepted: 01/28/2019] [Indexed: 12/13/2022]
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19
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Fang W, Xue S, Deng P, Zhang X, Wang X, Xiao Y, Fang Z. AmyZ1: a novel α-amylase from marine bacterium Pontibacillus sp. ZY with high activity toward raw starches. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:95. [PMID: 31044008 PMCID: PMC6477751 DOI: 10.1186/s13068-019-1432-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 04/12/2019] [Indexed: 05/03/2023]
Abstract
BACKGROUND Starch is an inexpensive and renewable raw material for numerous industrial applications. However, most starch-based products are not cost-efficient due to high-energy input needed in traditional enzymatic starch conversion processes. Therefore, α-amylase with high efficiency to directly hydrolyze high concentration raw starches at a relatively lower temperature will have a profound impact on the efficient application of starch. RESULTS A novel raw starch digesting α-amylase (named AmyZ1) was screened and cloned from a deep-sea bacterium Pontibacillus sp. ZY. Phylogenetic analysis showed that AmyZ1 was a member of subfamily 5 of glycoside hydrolase family 13. When expressed in Escherichia coli, the recombinant AmyZ1 showed high activity at pH 6.0-7.5 and 25-50 °C. Its optimal pH and temperature were 7.0 and 35 °C, respectively. Similar to most α-amylases, AmyZ1 activity was enhanced (2.4-fold) by 1.0 mM Ca2+. Its half-life time at 35 °C was also extended from about 10 min to 100 min. In comparison, AmyZ1 showed a broad substrate specificity toward raw starches, including those derived from rice, corn, and wheat. The specific activity of AmyZ1 towards raw rice starch was 12,621 ± 196 U/mg, much higher than other reported raw starch hydrolases. When used in raw starch hydrolyzing process, AmyZ1 hydrolyzed 52%, 47% and 38% of 30% (w/v) rice, corn, and wheat starch after 4 h incubation. It can also hydrolyze marine raw starch derived from Chlorella pyrenoidosa, resulting in 50.9 mg/g DW (dry weight of the biomass) of reducing sugars after 4 h incubation at 35 °C. Furthermore, when hydrolyzing raw corn starch using the combination of AmyZ1 and commercial glucoamylase, the hydrolysis rate reached 75% after 4.5 h reaction, notably higher than that obtained in existing starch-processing industries. CONCLUSIONS As a novel raw starch-digesting α-amylase with high specific activity, AmyZ1 efficiently hydrolyzed raw starches derived from both terrestrial and marine environments at near ambient temperature, suggesting its application potential in starch-based industrial processes.
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Affiliation(s)
- Wei Fang
- School of Life Sciences, Anhui University, Hefei, 230601 Anhui China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601 Anhui China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601 Anhui China
| | - Saisai Xue
- School of Life Sciences, Anhui University, Hefei, 230601 Anhui China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601 Anhui China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601 Anhui China
| | - Pengjun Deng
- School of Life Sciences, Anhui University, Hefei, 230601 Anhui China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601 Anhui China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601 Anhui China
| | - Xuecheng Zhang
- School of Life Sciences, Anhui University, Hefei, 230601 Anhui China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601 Anhui China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601 Anhui China
| | - Xiaotang Wang
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199 USA
| | - Yazhong Xiao
- School of Life Sciences, Anhui University, Hefei, 230601 Anhui China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601 Anhui China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601 Anhui China
| | - Zemin Fang
- School of Life Sciences, Anhui University, Hefei, 230601 Anhui China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, 230601 Anhui China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, 230601 Anhui China
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20
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Efficient Expression of Maltohexaose-Forming α-Amylase from Bacillus stearothermophilus in Brevibacillus choshinensis SP3 and Its Use in Maltose Production. BIOMED RESEARCH INTERNATIONAL 2017; 2017:5479762. [PMID: 29250543 PMCID: PMC5700550 DOI: 10.1155/2017/5479762] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 08/23/2017] [Accepted: 10/10/2017] [Indexed: 11/17/2022]
Abstract
The maltohexaose-forming, Ca2+-independent α-amylase gene from Bacillus stearothermophilus (AmyMH) was efficiently expressed in Brevibacillus choshinensis SP3. To improve the production of AmyMH in B. choshinensis SP3, the temperature and initial pH of culture medium were optimized. In addition, single-factor and response surface methodologies were pursued to optimize culture medium. Addition of proline to the culture medium significantly improved the production of recombinant α-amylase in B. choshinensis SP3. This improvement may result from improved cellular integrity of recombinant B. choshinensis SP3 in existence of proline. Culture medium optimization resulted in an 8-fold improvement in α-amylase yield, which reached 1.72 × 104 U·mL−1. The recombinant α-amylase was applied to the production of maltose on a laboratory scale. A maltose content of 90.72%, which could be classified as an extremely high maltose syrup, could be achieved using 15% (m/v) corn starch as the substrate. This study demonstrated that the B. choshinensis SP3 expression system was able to produce substantial quantities of recombinant α-amylase that has potential application in the starch industry.
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21
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Li Z, Duan X, Chen S, Wu J. Improving the reversibility of thermal denaturation and catalytic efficiency of Bacillus licheniformis α-amylase through stabilizing a long loop in domain B. PLoS One 2017; 12:e0173187. [PMID: 28253342 PMCID: PMC5333897 DOI: 10.1371/journal.pone.0173187] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/16/2017] [Indexed: 11/29/2022] Open
Abstract
The reversibility of thermal denaturation and catalytic efficiency of Bacillus licheniformis α-amylase were improved through site-directed mutagenesis. By using multiple sequence alignment and PoPMuSiC algorithm, Ser187 and Asn188, which located within a long loop in Domain B of Bacillus licheniformis α-amylase, were selected for mutation. In addition, Ala269, which is adjacent to Ser187 and Asn188, was also investigated. Seven mutants carrying the mutations S187D, N188T, N188S, A269K, A269K/S187D, S187D/N188T, and A269K/S187D/N188T were generated and characterized. The most thermostable mutant, A269K/S187D/N188T, exhibited a 9-fold improvement in half-life at 95°C and pH 5.5, compared with that of the wild-type enzyme. Mutant A269K/S187D/N188T also exhibited improved catalytic efficiency. The catalytic efficiency of mutant A269K/S187D/N188T reached 5.87×103±0.17 g·L-1·s-1 at pH 5.5, which is 1.84-fold larger than the corresponding value determined for the wild-type enzyme. Furthermore, the structure analysis showed that immobilization of the loop containing Ser187 and Asn188 plays a significant role in developing the properties of Bacillus licheniformis α-amylase.
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Affiliation(s)
- Zhu Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
| | - Xuguo Duan
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
- Department of Food Science and Engineering, College of Light Industry Science and Engineering, Nanjing Forestry University, Nanjing, China
| | - Sheng Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
| | - Jing Wu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
- * E-mail:
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22
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The hyperthermophilic α-amylase from Thermococcus sp. HJ21 does not require exogenous calcium for thermostability because of high-binding affinity to calcium. J Microbiol 2017; 55:379-387. [PMID: 28251549 DOI: 10.1007/s12275-017-6416-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 12/19/2016] [Accepted: 01/11/2017] [Indexed: 10/20/2022]
Abstract
The hyperthermophilic α-amylase from Thermococcus sp. HJ21 does not require exogenous calcium ions for thermostability, and is a promising alternative to commercially available α-amylases to increase the efficiency of industrial processes like the liquefaction of starch. We analyzed the amino acid sequence of this α-amylase by sequence alignments and structural modeling, and found that this α-amylase closely resembles the α-amylase from Pyrococcus woesei. The gene of this α-amylase was cloned in Escherichia coli and the recombinant α-amylase was overexpressed and purified with a combined renaturation-purification procedure. We confirmed thermostability and exogenous calcium ion independency of the recombinant α-amylase and further investigated the mechanism of the independency using biochemical approaches. The results suggested that the α-amylase has a high calcium ion binding affinity that traps a calcium ion that would not dissociate at high temperatures, providing a direct explanation as to why the addition of calcium ions is not required for thermostability. Understanding of the mechanism offers a strong base on which to further engineer properties of this α-amylase for better potential applications in industrial processes.
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