Enzyme and Microbial Technology最新文献

{"title":"Antioxidant capacity of xylooligosaccharides generated from beechwood xylan by recombinant family GH10 Aspergillus niger xylanase A and insights into the enzyme's competitive inhibition by riceXIP","authors":"Keer Zhang,&nbsp;Xinyu Qi,&nbsp;Ningxin Feng,&nbsp;Yuzhu Wang,&nbsp;Huiwen Wei,&nbsp;Mingqi Liu","doi":"10.1016/j.enzmictec.2024.110456","DOIUrl":"https://doi.org/10.1016/j.enzmictec.2024.110456","url":null,"abstract":"<div><p>In this study, the family GH10 xylanase AnXylA10 derived from <em>Aspergillus niger</em> JL15 strain was expressed in <em>Pichia pastoris</em> X33. The recombinant xylanase, reAnXylA10 exhibited optimal activity at 40 ℃ and pH 5.0. The hydrolysates generated from beechwood xylan using reAnXylA10 primarily consisted of xylobiose (X2) to xylohexaose (X6) and demonstrated remarkable antioxidant capacity. Furthermore, the rice xylanase inhibitory protein (riceXIP) was observed to competitively inhibit reAnXylA10, exhibiting an inhibition constant (<em>K</em>_<em>i</em>) of 140.6 nM. Molecular dynamics (MD) simulations of AnXylA10-riceXIP complex revealed that the α-7 helix (Q225-S238) of riceXIP intruded into the catalytic pocket of AnXylA10, thereby obstructing substrate access to the active site. Specifically, residue K226 of riceXIP formed robust interactions with E136 and E242, the two catalytic sites of AnXylA10, predominantly through high-occupied hydrogen bonds. Based on QTAIM, electron densities for the atom pairs K226_riceXIP@HZ1-E136_AnXylA10@OE2 and K226_riceXIP@HZ3-E242_AnXylA10@OE1 were determined to be 0.04628 and 0.02914 a.u., respectively. Binding free energy of AnXylA10-riceXIP complex was −59.0±7.6 kcal/mol, significantly driven by electrostatic and van der Waals forces. Gaining insights into the interaction between xylanase and its inhibitors, and mining the inhibition mechanism in depth, will facilitate the design of innovative GH10 family xylanases that are both highly efficient and resistant to inhibitors.</p></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"179 ","pages":"Article 110456"},"PeriodicalIF":3.4,"publicationDate":"2024-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140947311","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":"Whole-cell bioconversion for producing thymoquinone by engineered Saccharomyces cerevisiae","authors":"Eunjee Kim,&nbsp;Minsun Kim,&nbsp;Min-Kyu Oh","doi":"10.1016/j.enzmictec.2024.110455","DOIUrl":"https://doi.org/10.1016/j.enzmictec.2024.110455","url":null,"abstract":"<div><p>Thymoquinone, extracted from the black seeds of <em>Nigella sativa</em>, is a natural substance with highly beneficial effects against various human diseases. In this study, we aimed to construct a <em>Saccharomyces cerevisiae</em> strain that, produce thymoquinone from thymol, a relatively inexpensive substrate. To achieve this, cytochrome P450 from <em>Origanum vulgare</em> was expressed in <em>S. cerevisiae</em> for the bioconversion of thymol to thymoquinone, with the co-expression of cytochrome P450 reductase (CPR) from <em>Arabidopsis thaliana</em>, ATR1. Additionally, flexible linkers were used to connect these two enzymes. Furthermore, modifications were performed to expand the endoplasmic reticulum (ER) space, leading to increased thymoquinone production. After integrating the genes into the chromosome and optimizing the media components, a significant improvement in the thymol-to-thymoquinone conversion rate and yield were achieved. This study represents a possibility of the production of thymoquinone, a bioactive ingredient of a plant, using an engineered microbial cell.</p></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"178 ","pages":"Article 110455"},"PeriodicalIF":3.4,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140893919","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":"Rational design improves both thermostability and activity of a new D-tagatose 3-epimerase from Kroppenstedtia eburnean to produce D-allulose","authors":"Dingyu Guo ,&nbsp;Zhengchao Wang ,&nbsp;Wanqing Wei ,&nbsp;Wei Song ,&nbsp;Jing Wu ,&nbsp;Jian Wen ,&nbsp;Guipeng Hu ,&nbsp;Xiaomin Li ,&nbsp;Cong Gao ,&nbsp;Xiulai Chen ,&nbsp;Liming Liu","doi":"10.1016/j.enzmictec.2024.110448","DOIUrl":"https://doi.org/10.1016/j.enzmictec.2024.110448","url":null,"abstract":"<div><p>D-allulose is a naturally occurring rare sugar and beneficial to human health. However, the efficient biosynthesis of D-allulose remains a challenge. Here, we mined a new D-tagatose 3-epimerase from <em>Kroppenstedtia eburnean</em> (KeDt3e) with high catalytic efficiency. Initially, crucial factors contributing to the low conversion of KeDt3e were identified through crystal structure analysis, density functional theory calculations (DFT), and molecular dynamics (MD) simulations. Subsequently, based on the mechanism, combining restructuring the flexible region, proline substitution based onconsensus sequence analysis, introducing disulfide bonds, and grafting properties, and reshaping the active center, the optimal mutant M5 of KeDt3e was obtained with enhanced thermostability and activity. The optimal mutant M5 exhibited an enzyme activity of 130.8 U/mg, representing a 1.2-fold increase; T_m value increased from 52.7 °C to 71.2 °C; and half-life at 55 °C extended to 273.7 min, representing a 58.2-fold improvement, and the detailed mechanism of performance improvement was analyzed. Finally, by screening the ribosome-binding site (RBS) of the optimal mutant M5 recombinant bacterium (G01), the engineered strain G08 with higher expression levels was obtained. The engineered strain G08 catalyzed 500 g/L D-fructose to produce 172.4 g/L D-allulose, with a conversion of 34.4% in 0.5 h and productivity of 344.8 g/L/h on a 1 L scale. This study presents a promising approach for industrial-scale production of D-allulose.</p></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"178 ","pages":"Article 110448"},"PeriodicalIF":3.4,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140641040","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":"Physiological and biochemical characteristics of the carbon ion beam irradiation-generated mutant strain Clostridium butyricum FZM 240 in vitro and in vivo","authors":"Ya-Juan Wang ,&nbsp;Xiang Zhou ,&nbsp;Miao-Miao Zhang ,&nbsp;Mei-Han Liu ,&nbsp;Nan Ding ,&nbsp;Qing-Feng Wu ,&nbsp;Cai-Rong Lei ,&nbsp;Zi-Yi Dong ,&nbsp;Jun-Le Ren ,&nbsp;Jing-Ru Zhao ,&nbsp;Cheng-Lin Jia ,&nbsp;Jun Liu ,&nbsp;Bo Zhou ,&nbsp;Dong Lu","doi":"10.1016/j.enzmictec.2024.110447","DOIUrl":"https://doi.org/10.1016/j.enzmictec.2024.110447","url":null,"abstract":"<div><p><em>Clostridium butyricum</em> (<em>C. butyricum</em>) represents a new generation of probiotics, which is beneficial because of its good tolerance and ability to produce beneficial metabolites, such as short-chain fatty acids and enzymes; however, its low enzyme activity limits its probiotic efficacy. In this study, a mutant strain, <em>C. butyricum FZM 240</em> was obtained using carbon ion beam irradiation, which exhibited greatly improved enzyme production and tolerance. The highest filter paper, endoglucanase, and amylase activities produced by <em>C. butyricum FZM 240</em> were 125.69 U/mL, 225.82 U/ mL, and 252.28 U/mL, which were 2.58, 1.95, and 2.21-fold higher, respectively, than those of the original strain. The survival rate of the strain increased by 11.40 % and 5.60 % after incubation at 90 °C for 5 min and with simulated gastric fluid at pH 2.5 for 2 h, respectively, compared with that of the original strain. Whole-genome resequencing and quantitative real-time PCR(qRT-PCR) analysis showed that the expression of genes related to enzyme synthesis (<em>GE000348</em>, <em>GE001963</em> and <em>GE003123</em>) and tolerance (<em>GE001114</em>) was significantly up-regulated, while that of genes related to acid metabolism (<em>GE003450</em>) was significantly down-regulated. On this basis, homology modeling and functional prediction of the proteins encoded by the mutated genes were performed. According to the results, the properties related to the efficacy of <em>C. butyricum</em> as a probiotic were significantly enhanced by carbon ion beam irradiation, which is a novel strategy for the application of <em>Clostridium spp.</em> as feed additives.</p></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"178 ","pages":"Article 110447"},"PeriodicalIF":3.4,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140555621","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":"Design of a synthetic enzyme cascade for the in vitro fixation of formaldehyde to acetoin","authors":"Zhenzhen Cui ,&nbsp;Mengnan Ding ,&nbsp;Wei Dai ,&nbsp;Meiyu Zheng ,&nbsp;Zhiwen Wang ,&nbsp;Tao Chen","doi":"10.1016/j.enzmictec.2024.110446","DOIUrl":"https://doi.org/10.1016/j.enzmictec.2024.110446","url":null,"abstract":"<div><p>Formaldehyde (FALD) has gained prominence as an essential C1 building block in the synthesis of valuable chemicals. However, there are still challenges in converting FALD into commodities. Recently, cell-free biocatalysis has emerged as a popular approach for producing such commodities. Acetoin, also known as 3-hydroxy-2-butanone, has been widely used in food, cosmetic, agricultural and the chemical industry. It is valuable to develop a process to produce acetoin from FALD. In this study, a cell-free multi-enzyme catalytic system for the production of acetoin using FALD as the substrate was designed and constructed. It included three scales: FALD utilization pathway, glycolysis pathway and acetoin synthesis pathway. After the optimization of the reaction system, 20.17 mM acetoin was produced from 122 mM FALD, with a yield of 0.165 mol/mol, reaching 99.0% of the theoretical yield. The pathway provides a new approach for high-yield acetoin production from FALD, which consolidates the foundation for the production of high value-added chemicals using cheap one-carbon compounds.</p></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"178 ","pages":"Article 110446"},"PeriodicalIF":3.4,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140555622","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":"Development of an enzyme-linked phage receptor-binding protein assay (ELPRA) based on a novel biorecognition molecule- receptor-binding protein Gp130 of Pseudomonas aeruginosa bacteriophage Henu5","authors":"Yu Ning ,&nbsp;Tieshan Teng ,&nbsp;Xuehan Wu ,&nbsp;Menglu Wang ,&nbsp;Xin Jiao ,&nbsp;Jinjuan Qiao","doi":"10.1016/j.enzmictec.2024.110442","DOIUrl":"https://doi.org/10.1016/j.enzmictec.2024.110442","url":null,"abstract":"<div><p><em>Pseudomonas aeruginosa</em> is a Gram-negative bacterium associated with life-threatening healthcare-associated infections (HAIs), including burn wound infections, pneumonia and sepsis. Moreover, <em>P. aeruginosa</em> has been considered a pathogen of global concern due to its rising antibiotic resistance. Efficient identification of <em>P. aeruginosa</em> would significantly benefit the containment of bacterial infections, prevent pathogen transmission, and provide orientated treatment options. The accuracy and specificity of bacterial detection are primarily dictated by the biorecognition molecules employed. Lytic bacteriophages (or phages) could specifically attach to and lyse host bacterial cells. Phages’ host specificity is typically determined by their receptor-binding proteins (RBPs), which recognize and adsorb phages to particular bacterial host receptors. This makes RBPs promising biorecognition molecules in bacterial detection. This study identified a novel RBP (Gp130) from the <em>P. aeruginosa</em> phage Henu5. A modified enzyme-linked phage receptor-binding protein assay (ELPRA) was developed for <em>P. aeruginosa</em> detection employing Gp130 as biorecognition molecules. Optimized conditions provided a calibration curve for <em>P. aeruginosa</em> with a range from 1.0 × 10³ to 1.0 × 10⁷ CFU/mL, with a limit of detection as low as 10 CFU/mL in phosphate-buffered saline (PBS). With VITEK^Ⓡ 2 Compact system identification (40 positives and 21 negatives) as the gold standard, the sensitivity of ELPRA was 0.950 (0.818–0.991), and the specificity was 0.905 (0.682–0.983) within a 95 %confidence interval. Moreover, the recovery test in spiked mouse serum showed recovery rates ranging from 82.79 %to 98.17%, demonstrating the prospect of the proposed ELPRA for detecting <em>P. aeruginosa</em> in biological samples.</p></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"177 ","pages":"Article 110442"},"PeriodicalIF":3.4,"publicationDate":"2024-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140534958","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":"Production of recombinant glycosidases fused with Usp45 and SpaX to avoid the purification and immobilization stages","authors":"José Antonio Curiel ,&nbsp;Estela de Vega ,&nbsp;Susana Langa ,&nbsp;Ángela Peirotén ,&nbsp;José María Landete","doi":"10.1016/j.enzmictec.2024.110445","DOIUrl":"https://doi.org/10.1016/j.enzmictec.2024.110445","url":null,"abstract":"<div><p>The elucidation of the physicochemical properties of glycosidases is essential for their subsequent technological application, which may include saccharide hydrolysis processes and oligosaccharide synthesis. As the application of cloning, purification and enzymatic immobilization methods can be time consuming and require a heavy financial investment, this study has validated the recombinant production of the set of <em>Lacticaseibacillus rhamnosus</em> fucosidases fused with Usp45 and SpaX anchored to the cell wall of <em>Lacticaseibacillus cremoris</em> subsp <em>cremoris</em> MG1363, with the aim of avoiding the purification and stabilization steps. The cell debris harboring the anchored AlfA, AlfB and AlfC fucosidases showed activity against <em>p</em>-nitrophenyl α-L-fucopyranoside of 6.11 ± 0.36, 5.81 ± 0.29 and 9.90 ± 0.58 U/mL, respectively, and exhibited better thermal stability at 50 °C than the same enzymes in their soluble state. Furthermore, the anchored AlfC fucosidase transfucosylated different acceptor sugars, achieving fucose equivalent concentrations of 0.94 ± 0.09 mg/mL, 4.11 ± 0.21 mg/mL, and 4.08 ± 0.15 mg/mL of fucosylgalatose, fucosylglucose and fucosylsucrose, respectively.</p></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"178 ","pages":"Article 110445"},"PeriodicalIF":3.4,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0141022924000528/pdfft?md5=dc25254c38c47fc056ef5c9cf0274bda&pid=1-s2.0-S0141022924000528-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140348089","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":"Chitosanase-immobilized magnetite-agar gel particles as a highly stable and reusable biocatalyst for enhanced production of physiologically active chitosan oligosaccharides","authors":"Takashi Kuroiwa,&nbsp;Yuta Nakagawa,&nbsp;Ryuichi Takayanagi,&nbsp;Akihiko Kanazawa","doi":"10.1016/j.enzmictec.2024.110443","DOIUrl":"https://doi.org/10.1016/j.enzmictec.2024.110443","url":null,"abstract":"<div><p>A novel immobilized chitosanase was developed and utilized to produce chitosan oligosaccharides (COSs) via chitosan hydrolysis. Magnetite-agar gel particles (average particle diameter: 338 μm) were prepared by emulsifying an aqueous agar solution dispersing 200-nm magnetite particles with isooctane containing an emulsifier at 80 °C, followed by cooling the emulsified mixture. The chitosanase from <em>Bacillus pumilus</em> was immobilized on the magnetite-agar gel particles chemically activated by introducing glyoxyl groups with high immobilization yields (&gt;80%), and the observed specific activity of the immobilized chitosanase was 16% of that of the free enzyme. This immobilized chitosanase could be rapidly recovered from aqueous solutions by applying magnetic force. The thermal stability of the immobilized chitosanase improved remarkably compared with that of free chitosanase: the deactivation rate constants at 35 °C of the free and immobilized enzymes were 8.1 × 10⁻⁵ and 3.9 × 10⁻⁸ s⁻¹, respectively. This immobilized chitosanase could be reused for chitosan hydrolysis at 75 °C and pH 5.6, and 80% of its initial activity was maintained even after 10 cycles of use. COSs with a degree of polymerization (DP) of 2–7 were obtained using this immobilized chitosanase, and the product content of physiologically active COSs (DP ≥ 5) reached approximately 50%.</p></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"178 ","pages":"Article 110443"},"PeriodicalIF":3.4,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140536133","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":"Efficient activity screening of new glucuronoyl esterases using a pNP-based assay","authors":"Michael S. Madsen ,&nbsp;Pedro A. Martins ,&nbsp;Jane W. Agger","doi":"10.1016/j.enzmictec.2024.110444","DOIUrl":"https://doi.org/10.1016/j.enzmictec.2024.110444","url":null,"abstract":"<div><p>Glucuronoyl esterases (CE15, EC 3.1.1.117) catalyze the hydrolysis of ester bonds between lignin and carbohydrates in lignocellulose. They are widespread within fungi and bacteria, and are subjects to research interest due to their potential applicability in lignocellulose processing. Identifying new and relevant glucuronoyl esterase candidates is challenging because available model substrates poorly represent the natural substrate, which leads to inefficient screening for the activity. In this study, we demonstrate how fifteen novel, fungal, putative glucuronoyl esterases from family CE15 were expressed and screened for activity towards a commercially available, colorimetric assay based on the methyl-ester of 4-<em>O</em>-methyl-aldotriuronic acid linked to para-nitrophenol (methyl ester-UX-β-pNP) and coupled with the activity of GH67 (α-glucuronidase) and GH43 (β-xylosidase) activity. The assay provides easy means for accurately establishing activity and determining specific activity of glucuronoyl esterases. Out of the fifteen expressed CE15 proteins, seven are active and were purified to determine their specific activity. The seven active enzymes originate from <em>Auricularia subglabra</em> (3 proteins), <em>Ganoderma sinensis</em> (2 proteins) <em>and Neocallimastix californiae</em> (2 proteins). Among the CE15 proteins not active towards the screening substrate (methyl ester-UX-β-pNP) were proteins originating from <em>Schizophyllum commune, Podospora anserina</em>, <em>Trametes versicolor</em>, and <em>Coprinopsis cinerea</em>. It is unexpected that CE15 proteins from such canonical lignocellulose degraders do not have the anticipated activity, and these observations call for deeper investigations.</p></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"178 ","pages":"Article 110444"},"PeriodicalIF":3.4,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0141022924000516/pdfft?md5=07a7cc13cdeee464fe28c92b27f95715&pid=1-s2.0-S0141022924000516-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140348090","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":"Bioinformatics-based identification of GH12 endoxyloglucanases in citrus-pathogenic Penicillium spp","authors":"Kai Li ,&nbsp;Kristian Barrett,&nbsp;Jane W. Agger,&nbsp;Birgitte Zeuner,&nbsp;Anne S. Meyer","doi":"10.1016/j.enzmictec.2024.110441","DOIUrl":"https://doi.org/10.1016/j.enzmictec.2024.110441","url":null,"abstract":"<div><p>Millions of tons of citrus peel waste are produced every year as a byproduct of the juice industry. Citrus peel is rich in pectin and xyloglucan, but while the pectin is extracted for use in the food industry, the xyloglucan is currently not valorized. To target hydrolytic degradation of citrus peel xyloglucan into oligosaccharides, we have used bioinformatics to identify three glycoside hydrolase 12 (GH12) endoxyloglucanases (EC 3.2.1.151) from the citrus fruit pathogens <em>Penicillium italicum</em> GL-Gan1 and <em>Penicillium digitatum</em> Pd1 and characterized them on xyloglucan obtained by alkaline extraction from citrus peel. The enzymes displayed pH-temperature optima of pH 4.6–5.3 and 35–37°C. PdGH12 from <em>P. digitatum</em> and PiGH12A from <em>P. italicum</em> share 84% sequence identity and displayed similar kinetics, although <em>k</em>_cat was highest for PdGH12. In contrast, PiGH12B from <em>P. italicum</em>, which has the otherwise conserved Trp in subsite −4 replaced with a Tyr, displayed a 3 times higher <em>K</em>_M and a 4 times lower <em>k</em>_cat/<em>K</em>_M than PiGH12A, but was the most thermostable enzyme of the three <em>Penicillium-</em>derived endoxyloglucanases. The benchmark enzyme AnGH12 from <em>Aspergillus nidulans</em> was more thermally stable and had a higher pH-temperature optimum than the enzymes from <em>Penicillum</em> spp. The difference in structure of the xyloglucan oligosaccharides extracted from citrus peel xyloglucan and tamarind xyloglucan by the new endoxyloglucanases was determined by LC-MS. The inclusion of citrus peel xyloglucan demonstrated that the endoxyloglucanases liberated fucosylated xyloglucan oligomers, implying that these enzymes have the potential to upgrade citrus peel residues to produce oligomers useful as intermediates or bioactive compounds.</p></div>","PeriodicalId":11770,"journal":{"name":"Enzyme and Microbial Technology","volume":"178 ","pages":"Article 110441"},"PeriodicalIF":3.4,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0141022924000486/pdfft?md5=7f8ca7745234295366d8be25b88e5080&pid=1-s2.0-S0141022924000486-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140345255","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}