Enzyme and Microbial Technology最新文献

{"title":"Production of bio-indigo from engineered Pseudomonas putida KT2440 harboring tryptophanase and flavin-containing monooxygenase","authors":"Hyun Jin Kim ,&nbsp;Suwon Kim ,&nbsp;Yeda Lee ,&nbsp;Yuni Shin ,&nbsp;Suhye Choi ,&nbsp;Jinok Oh ,&nbsp;Jaeho Jeong ,&nbsp;HyunA Park ,&nbsp;Jungoh Ahn ,&nbsp;Jeong Chan Joo ,&nbsp;Kwon-Young Choi ,&nbsp;Shashi Kant Bhatia ,&nbsp;Yung-Hun Yang","doi":"10.1016/j.enzmictec.2024.110529","DOIUrl":"10.1016/j.enzmictec.2024.110529","url":null,"abstract":"<div><div>Indigo is a unique blue dye that has been used in the textile industry for centuries and is currently mass-produced commercially through chemical synthesis. However, the use of toxic substrates and reducing agents for chemical synthesis is associated with environmental concerns, necessitating the development of eco-friendly alternatives based on microbial production. In this study, a robust industrial strategy for indigo production was developed using <em>Pseudomonas putida</em> KT2440 as the host strain, which is characterized by its excellent ability to degrade aromatic compounds and high resistance to environmental stress. By introducing the genes tryptophanase (<em>tnaA</em>) and Flavin-containing monooxygenase <em>(FMO</em>), a <em>P. putida</em> HI201 strain was constructed to produce indigo from tryptophan. To enhance the indigo yield, culture conditions, including medium composition, temperature, tryptophan concentration, and shaking speed, were optimized. Under optimal conditions such as TB medium, 15 mM tryptophan, 30°C, 200 rpm, <em>P. putida</em> HI201 biosynthesized 1.31 g/L indigo from tryptophan in a fed-batch fermentation system. The introduction of <em>tnaA</em> and <em>FMO</em> genes also enabled the production of indigo in various <em>P. putida</em> species, and the indigo-producing strain had a blue color, which served as a visual indicator. This study presents a strategy for using <em>P. putida</em> as a host for robust and sustainable microbial production of indigo, highlighting the strain's applicability and efficiency in environment friendly dye synthesis.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"182 ","pages":"Article 110529"},"PeriodicalIF":3.4,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142497336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Targeted metagenomics – Enrichment for enzymes active on sulfated polysaccharides from seaweeds","authors":"Bjorn Thor Adalsteinsson ,&nbsp;Hörður Guðmundsson ,&nbsp;Andrius Jasilionis ,&nbsp;Morten Schiøtt ,&nbsp;Maria Dalgaard Mikkelsen ,&nbsp;Elísabet Eik Guðmundsdóttir ,&nbsp;Pavithra Sivakumar ,&nbsp;Annika Malmgren ,&nbsp;Tushar Kaushik ,&nbsp;Erik Apelqvist ,&nbsp;Signe Vangsgaard ,&nbsp;Rébecca Leblay ,&nbsp;Ólafur Friðjónsson ,&nbsp;Anne S. Meyer ,&nbsp;Eva Nordberg Karlsson ,&nbsp;Guðmundur Óli Hreggviðsson","doi":"10.1016/j.enzmictec.2024.110528","DOIUrl":"10.1016/j.enzmictec.2024.110528","url":null,"abstract":"<div><div>Seaweeds (macroalgae) are an attractive resource for diverse microbial- and enzymatic production processes. They are abundant, underutilized, cheap, and rich in carbohydrates, and therefore have the potential to be used as a source of mono- or oligosaccharides, and as substrates for industrial fermentation processes. Many seaweed polysaccharides, including the sulfated polysaccharides ulvan and fucoidan, are however complex and heterogenous in structure, and there are currently few enzymes available to modify them, and understanding of their enzymatic depolymerization remains limited. The present study aimed to identify and characterize robust fucoidanases and ulvan lyases. Metagenomes were obtained from microbial enrichments from an intertidal hot-spring, genes identified that expressed putative fucoidanases and ulvan lyases, and following gene cloning and expression, the respective enzymes were screened for enzymatic activity. Consistent with their origin, the identified protein sequences were considerably divergent from previously characterized enzymes, with a 44 % average maximal sequence identity. In total, the study resulted in the characterization of 10 new fucoidanases (GH107 and GH168 families) and 8 new ulvan lyases (PL24, PL25 and PL40 families). Notably, the new fucoidanases appeared to have functional specificity towards fucoidan containing α-1,3 linked L-fucosyl and several functioned at high temperature. The study contributes a metagenomics-based approach to identify new seaweed polysaccharide degrading enzymes and an increased understanding of the diversity of such enzymes, which may have implications for the realization of biotechnology based valorization of seaweed biomass.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"182 ","pages":"Article 110528"},"PeriodicalIF":3.4,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metabolic engineering of the borneol and camphor degradation pathways in Pseudomonas to produce optically pure bicyclic monoterpenes","authors":"Yi-An Hong ,&nbsp;Aye Aye Khine ,&nbsp;Yu-Wei Lin ,&nbsp;Pei-Yun Lee ,&nbsp;Wei-Xiang Hong ,&nbsp;Anren Hu ,&nbsp;Tzenge-Lien Shih ,&nbsp;Hao-Ping Chen","doi":"10.1016/j.enzmictec.2024.110527","DOIUrl":"10.1016/j.enzmictec.2024.110527","url":null,"abstract":"<div><div>Borneol, a medicinally important bicyclic monoterpene, facilitates drug transport across mucous membranes and the blood-brain barrier. Derivatives of borneol and camphor also have numerous biomedical applications. Borneol is currently industrially synthesized via the conversion of turpentine and α-pinene. However, the major product is racemic isoborneol rather than racemic borneol. Both borneol and isoborneol are degraded by the soil bacterium <em>Pseudomonas</em> via a well-established degradation pathway. Two indigenous <em>Pseudomonas</em> strains were used to convert racemic isoborneol to other optically pure bicyclic monoterpenes here. Our results showed that deletion of the <em>camE</em>_<em>2,5</em> gene alone from the strain TCU-HL1 genome led to the complete loss of borneol and camphor degradation ability. Knockout of both <em>camE</em>_<em>2,5</em> and <em>bdh1</em> (TCU-HL1<em>Δbdh1ΔcamE</em>_<em>2,5</em>) restored the degradation capability as the role of Bdh1 was replaced by that of Bdh2. This mutant converted racemic isoborneol into an optically pure bicyclic monoterpene, 2,5-diketocamphane, with a 45 % recovery yield. RT-qPCR results suggested that <em>camE</em>_<em>2,5</em> expression plays a pivotal role in regulating the borneol/camphor degradation cluster. While (+)-borneol, (–)-borneol and (+)-camphor can be obtained from plants for mass production purposes, (–)-camphor cannot be obtained in the same manner. <em>P. monteilii</em> TCU-CK1 converted racemic isoborneol into (–)-camphor and 3,6-diketocamphane, with 15 % and 10 % recovery yields, respectively. In conclusion, we report the role of <em>camE</em>_<em>2,5</em> in regulating the borneol/camphor degradation operon and biotransformation methods to produce several optically pure bicyclic monoterpenes.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"181 ","pages":"Article 110527"},"PeriodicalIF":3.4,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142460872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced soluble expression and characterization of human N-acetylglucosaminyltransferase IVa in Escherichia coli","authors":"Sen-Lin Peng ,&nbsp;Yi Ding ,&nbsp;Meng-Hai Xiang ,&nbsp;Ken Chen ,&nbsp;Xiao-Dong Gao ,&nbsp;Ning Wang","doi":"10.1016/j.enzmictec.2024.110524","DOIUrl":"10.1016/j.enzmictec.2024.110524","url":null,"abstract":"<div><div><em>N</em>-Glycosylation is one of the most important posttranslational modifications of proteins. Nearly the entire surface of cells and almost all secreted proteins in humans are modified with complex-type <em>N</em>-glycans, whose functions are affected by the number of <em>N</em>-glycan branches. <em>N</em>-Acetylglucosaminyltransferase-IVa (GnT-IVa) is a Golgi glycosyltransferase that transfers a GlcNAc to the α-1,3 mannose arm of the biantennary <em>N</em>-glycan GlcNAc2Man3GlcNAc2 to form a β-1,4 GlcNAc branched structure. The soluble expression of mammalian glycosyltransferases in heterologous hosts is often challenging. In the present study, human GnT-IVa (<em>Hs</em>GnT-IVa) was cloned as an N-terminal truncated form that was fused with solubility-enhancing tags or signal peptides and overexpressed in <em>Escherichia coli</em> (<em>E. coli</em>). Our results showed that recombinant <em>Hs</em>GnT-IVa could be overexpressed in its highest soluble and active form when the first 87 amino acids were removed and was fused with maltose-binding protein (MBP). By optimizing the induction conditions, the expression level of the recombinant protein was increased to yield approximately 540 mg per liter of culture after affinity purification. The purified enzyme exhibited appropriate glycosyltransferase activity, and the <em>K</em>_<em>m</em> value of the acceptor substrate was calculated as 1.1 mM. Characterization of the enzyme revealed that it reached its maximum activity with 5 mM Mn²⁺ at 37 °C in MES/NaOH (pH 7.0). In addition, the effects of key amino acids in the catalytic and lectin domains on enzyme activity were measured. This work offers an efficient approach for the large-scale production of bioactive <em>Hs</em>GnT-IVa, which can be used for in vitro synthesis and functional studies of multiantennary complex-type <em>N</em>-glycans.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"181 ","pages":"Article 110524"},"PeriodicalIF":3.4,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142460871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling six novel CALB-like lipases using genome-centric and patent-driven prospection","authors":"Priscila Esteves de Faria ,&nbsp;Gabriel Stamato Nunes ,&nbsp;Gabriela Coelho Brêda ,&nbsp;Erika Cristina Gonçalves Aguieiras ,&nbsp;Maria Beatriz Santos Mota ,&nbsp;Leticia Dobler ,&nbsp;Denise Maria Guimarães Freire ,&nbsp;Rodrigo Volcan Almeida ,&nbsp;Rafael Dias Mesquita","doi":"10.1016/j.enzmictec.2024.110525","DOIUrl":"10.1016/j.enzmictec.2024.110525","url":null,"abstract":"<div><div>Lipases present biotechnological applications in various industrial sectors due to their ability to perform multiple biochemical reactions. However, the high cost sometimes discourages their potential uses, besides the extensive number of patents involving them. One of the most utilized and researched lipases is <em>Candida antarctica</em> lipase B (CALB), known for its versatility, encompassing enantioselectivity, thermostability, and a wide range of substrates. Therefore, finding new CALB-like lipases is an interesting strategy to enable the implementation of biocatalysts, especially if intellectual property analysis is included. The present study identified and produced six CALB-like enzymes without patent protection, with differences in pocket amino acids and substrate specificity. We conducted genomic searches in almost 7000 Fungal genomes, identifying over 1500 unique CALB homolog candidates. The phylogenetic and intellectual property analysis filtered those results into a few sequences without protection that were very similar to CALB. One cloned lipase had a lower hydrophobicity at the pocket entrance and preferred the C4 p-nitrophenyl ester as substrate. Another had a wider opening and more polar pocket, showing no preference. These results identified new patent-free lipases with conserved essential catalytic elements and diverse substrate specificity due to variations in the catalytic pocket. These enzymes can be the starting point for biocatalyst innovation with potential applications in diverse biotechnological areas.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"181 ","pages":"Article 110525"},"PeriodicalIF":3.4,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial production of adipic acid from 6-hydroxyhexanoic acid for biocatalytic upcycling of polycaprolactone","authors":"Yu-Ri Oh ,&nbsp;Young-Ah Jang ,&nbsp;Gyeong Tae Eom","doi":"10.1016/j.enzmictec.2024.110521","DOIUrl":"10.1016/j.enzmictec.2024.110521","url":null,"abstract":"<div><div>To valorize waste polycaprolactone (PCL), one of the most widely used biodegradable plastics, into a value-added chemical, we upcycled 6-hydroxyhexanoic acid (6-HHA), the sole monomer of PCL, into adipic acid (AA) using a microbial method. Recombinant <em>Escherichia coli</em> strains expressing <em>chnD</em> (6-HHA dehydrogenase) and <em>chnE</em> (6-oxohexanoic acid dehydrogenase) genes from three bacteria were constructed, and all these strains successfully produced AA from 6-HHA. Among these, the <em>E. coli</em> strain harboring ChnDE genes from <em>Acinetobacter</em> strain SE19 (<em>E. coli</em> [pKK-AcChn]) showed the highest AA-producing ability. To increase the AA production titer, we optimized the culture temperature of this strain in flask culture and performed fed-batch fermentation in a 5 L bioreactor. After the fed-batch fermentation, the AA production titer increased to 15.6 g/L. As 6-HHA is a monomer of PCL, our results provide the groundwork for the development of a biocatalytic upcycling method of PCL.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"181 ","pages":"Article 110521"},"PeriodicalIF":3.4,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective transformation of crocin-1 to crocetin-glucosyl esters by β-glucosidase (Lf18920) from Leifsonia sp. ZF2019: Insights from molecular docking and point mutations","authors":"Xi Wang ,&nbsp;Chenzhi Zhuhuang ,&nbsp;Yi He,&nbsp;Xiaolong Zhang,&nbsp;Yan Wang,&nbsp;Qinxue Ni,&nbsp;Youzuo Zhang,&nbsp;Guangzhi Xu","doi":"10.1016/j.enzmictec.2024.110522","DOIUrl":"10.1016/j.enzmictec.2024.110522","url":null,"abstract":"<div><div>Crocetin di/mono-glucosyl esters (crocin-4 and crocin-5) are rarely distributed in nature, limiting their potential applications in the food and pharmaceutical industries. In the present study, a novel GH3 family β-glucosidase Lf18920 was identified from <em>Leifsonia</em> sp. ZF2019, which selectively hydrolyzed crocin-1 (crocetin di-gentiobiosyl ester) to crocin-5 and crocin-4, but not to its aglycone, crocetin. Under the optimal condition of 40 °C and pH 6.0 for 120 min, Lf18920 almost completely hydrolyzed crocin-1, yielding 73.50±5.66 % crocin-4 and 16.19±1.38 % crocin-5. Molecular docking and point mutation studies revealed that Lf18920 formed a narrow binding channel that facilitated crocin-1 binding. Five single amino acid variants (D50A, D53A, W274A, G420A, and Q421A) were constructed, all of which showed reduced hydrolytic activity. Mutations at D50 and D53, located distal to the active site, increased binding energy and decreased hydrolytic activity, while mutations at W274, G420, and Q421, proximal to the active site, disrupted hydrolytic function. These findings suggest that the narrow binding channel and specific enzyme-substrate interactions are crucial for Lf18920’s selective hydrolytic activity. Overall, this study is the first to report a β-glucosidase capable of selectively transforming crocin-1 to crocetin di/mono-glucosyl esters, offering potential for synthesizing crocin-4 and crocin-5.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"181 ","pages":"Article 110522"},"PeriodicalIF":3.4,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142388978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lignin-based monophenolic model compounds in L-tyrosine derivative synthesis via tyrosine phenol lyase","authors":"Idamaria Romakkaniemi,&nbsp;Johanna Panula-Perälä,&nbsp;Juha Ahola,&nbsp;Marja Mikola,&nbsp;Juha Tanskanen","doi":"10.1016/j.enzmictec.2024.110519","DOIUrl":"10.1016/j.enzmictec.2024.110519","url":null,"abstract":"<div><div>Tyrosine phenol lyase (TPL) synthesises L-tyrosine derivatives from monophenols, pyruvate and ammonia. Production of such high-value aromatic chemicals from biomass-derived raw materials is of great interest. In this study, six monophenols (guaiacol, phenol, o-cresol, m-cresol, catechol and syringol) were chosen based on the structure of lignin and were studied as substrates in the enzymatic reaction. Single monophenol reactions (SMR) and binary monophenol reactions (BMR) with guaiacol were carried out. TPL-M379V was found to be selective towards guaiacol (84.5 % conv.). The highest single activity was measured towards phenol (93.9 % conv.). However, the enzyme preferred guaiacol over phenol in the BMRs. Syringol was found to be inert in the reaction, whereas catechol had an inhibitory effect on the enzymatic reaction, in addition to causing degradation of all the substrates in the medium. Doubling the guaiacol concentration in the SMR did not significantly increase the production of 3-O-methyldopa (conv. 45.9 %). However, in the binary reaction systems the total monophenol conversions were higher with guaiacol and phenol (total 62.4 %) or o-cresol (total 57.1 %). This indicates possible substrate/product specific inhibition. The study provides new data on activity, selectivity and inhibitory effects of monophenols in the synthetic reaction catalysed by TPL-M379V, especially in mixed-substrate reactions.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"181 ","pages":"Article 110519"},"PeriodicalIF":3.4,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142380313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Protein engineering of an alkaline protease from Bacillus licheniformis (BLAP) for efficient and specific chiral resolution of the racemic ethyl tetrahydrofuroate","authors":"Xinjun Yu ,&nbsp;Yichao Li ,&nbsp;Zhaoxia Qian,&nbsp;Litian Wei,&nbsp;Jing Xie,&nbsp;Meijun Tong,&nbsp;Yinjun Zhang","doi":"10.1016/j.enzmictec.2024.110523","DOIUrl":"10.1016/j.enzmictec.2024.110523","url":null,"abstract":"<div><div>Enzymatic resolution of ethyl tetrahydrofuroate to produce (<em>S</em>)-2-ethyl tetrahydrofuroate and (<em>R</em>)-2-tetrahydrofuroic acid is a green biomanufacturing strategy. However, enzymatic activity and selectivity are still limiting factors of their industrial applications and development. In previous study, we incidentally found that a <em>Bacillus licheniformis</em> alkaline protease (BLAP), not a lipase, could specifically resolve ethyl tetrahydrofuroate to produce (<em>S</em>)-2-ethyl tetrahydrofuroate and (<em>R</em>)-2-tetrahydrofuroic acid. In this study, the point-saturation-mutation libraries based on the seven amino acid sites (L105, I113, P114, L115, V309, Y310, and M326) were constructed and screened using the molecular docking technology. It was found that activity of the mutant BLAP^Y310E reached 182.78 U/mL with high stereoselectivity, 3.14 times higher than that of the wild-type BLAP. Further simulated mutation analysis showed that the Y310E mutation increased the distance from the substrate ligand to the binding pocket from 2.3 Å to 4.5 Å, reducing steric hindrance to the active center. Under the optimal conditions and after 3.5 h of reaction catalyzed by BLAP^Y310E, 200 mM ethyl tetrahydrofuroate was converted to (<em>S</em>)-2-ethyl tetrahydrofuroate and (<em>R</em>)-2-tetrahydrofuroic acid with the <em>ee</em> values of 99.9 % and 68.63 %, respectively. The enantiomeric ratio of BLAP^Y310E was 105.5, which was 30.23 times higher than that of BLAP. This study advances the comprehension of protease activity and selectivity mechanisms in resolving ester substances and lays a robust foundation for the industrial production of the optically pure (<em>S</em>)-2-ethyl tetrahydrofuroate and (<em>R</em>)-2-tetrahydrofuroic acid via biological enzymatic methods.</div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"181 ","pages":"Article 110523"},"PeriodicalIF":3.4,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142388977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of lycopene β-cyclase from Dunaliella bardawil for enhanced β-carotene production and salt tolerance","authors":"Yu-Chen Xie ,&nbsp;Zhi-Wei Ye ,&nbsp;Jv-Liang Dai ,&nbsp;Hao-Hong Chen ,&nbsp;Jian-Guo Jiang","doi":"10.1016/j.enzmictec.2024.110520","DOIUrl":"10.1016/j.enzmictec.2024.110520","url":null,"abstract":"<div><div><em>Dunaliella</em> can accumulate more β-carotene (10 % or even more of the dry weight of cells) than any other species. Lycopene β-cyclase (LcyB) is the key enzyme in the catalysis of lycopene to β-carotene. In the present research, we used <em>Escherichia coli</em> BL21 (DE3) as host to construct two different types of engineering bacteria, one expressing the <em>D. bardawil</em> LcyB and the other expressing the orthologue <em>Erwinia uredovora</em> crtY. The catalytic ability of LcyB and CrtY were evaluated by comparing the β-carotene yields of the two <em>E. coli</em> BL21(DE3) strains, whose salt tolerance was simultaneously compared by cultivated them under different NaCl concentrations (1 %, 2 %, and 4 %). We also interfered with the <em>LcyB</em> gene to investigate the effect of <em>LcyB</em> in <em>D. bardawil</em>. Results displayed that the β-carotene yield of the LcyB-transformant significantly increased by about 48 % compared with the crtY-transformant. Additionally, <em>LcyB</em> was verified to be able to enhance the salt tolerance of <em>E. coli</em> BL21 (DE3). It is concluded that <em>D. bardawil</em> LcyB not only has better catalytic ability but also is able to confer salt tolerance to cells. Interfering <em>D. bardawil LcyB</em> induced the low expression of LcyB and the changes of growth and carotenoids metabolism in <em>D. bardawil.</em></div></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"181 ","pages":"Article 110520"},"PeriodicalIF":3.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142388976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}