Applied Microbiology and Biotechnology最新文献

{"title":"Biodeterioration of canvas paintings: microbial role and development of sustainable treatments for biocontrol","authors":"Giovanna Climaco,&nbsp;Gianmaria Oliva,&nbsp;Paola Fiore,&nbsp;Consiglia Tedesco,&nbsp;Stefano Castiglione,&nbsp;Giovanni Vigliotta","doi":"10.1007/s00253-025-13553-8","DOIUrl":"10.1007/s00253-025-13553-8","url":null,"abstract":"<p>Biodeterioration of paintings, caused by microorganisms interacting with the organic/inorganic compounds of the canvas, represents a serious problem for preserving cultural heritage. In our study, the microbial degradation caused on an eighteenth century painting “Sant’Anna, San Gioacchino e la Vergine Bambina” was investigated. Seventeen bacterial and six fungal strains on the altered parts of the canvas were identified, and their deteriorating ability were evaluated on two pictorial pigments: the yellow ochre and the ivory black. We recognized that microorganisms interacted with these pigments and modified their chromatic features. Furthermore, we adopted an eco-friendly antimicrobial treatment based on natural plant extracts (thymus, rosemary, and garlic) as an alternative to conventional biocides and highlighted how rosemary (<i>Salvia rosmarinus</i>) extract was the best and inhibited 74% of the isolated bacterial strains. When the extract was applied on the contaminated canvas, it reduced bacterial colonization by ~ 75% in only 48 h and eliminated the fungi within 7 days. The extract application was optimized, to minimize potential alterations of the painting caused by the extract, by adopting different strategies: (i) direct nebulization, (ii) Evolon® tissue (an innovative technical polyester-polyamide textile), and (iii) pretreatment with cyclomethicone D5. Finally, we also verified that it did not cause chromatic variations on the canvas confirming its suitability for conservation purposes. Our study provides new insights on the role of microorganisms in the deterioration of cultural heritage and highlights the potentiality of plant-based antimicrobials as sustainable, non-invasive, and alternative to traditional methods for the artwork preservation. Future research should focus on long-term efficacy assessments and formulation optimization to enhance applicability in heritage conservation practices.</p><p>• <i>Identification of 17 bacteria and 6 fungi from a deteriorate canvas painting</i></p><p>• <i>Microorganisms altered yellow ochre and ivory black, causing chromatic changes</i></p><p>• <i>Rosemary extract applied on canvas reduced microbial colonization</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"109 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00253-025-13553-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832086","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":"Functional and structural insights into a thermostable (S)-selective amine transaminase and its improved substrate scope by protein engineering","authors":"Stefania Patti,&nbsp;Simone A. De Rose,&nbsp;Michail N. Isupov,&nbsp;Ilaria Magrini Alunno,&nbsp;Sergio Riva,&nbsp;Erica Elisa Ferrandi,&nbsp;Jennifer A. Littlechild,&nbsp;Daniela Monti","doi":"10.1007/s00253-025-13536-9","DOIUrl":"10.1007/s00253-025-13536-9","url":null,"abstract":"<p>A (<i>S</i>)-selective amine transaminase from a <i>Streptomyces</i> strain, Sbv333-ATA, is a biocatalyst showing both high thermostability with a melting temperature of 85 °C and broad substrate specificity for the amino acceptor. This enzyme was further characterized both biochemically and structurally. The Sbv333-ATA is stable in the presence of up to 20% (<i>v</i>/<i>v</i>) of the water-miscible cosolvents methanol, ethanol, acetonitrile, and dimethyl sulfoxide, and in biphasic systems with petroleum ether, toluene, and ethyl acetate as an organic phase. The enzyme showed also a good activity toward different amino donors, such as (<i>S</i>)-methylbenzylamine and 2-phenylethylamine, aliphatic mono- and di-amines, like propylamine and cadaverine, and selected amino acids. However, more sterically hindered aromatic amines were not accepted. Based on the knowledge of the three-dimensional structures obtained, a rational approach to site specific mutagenesis was carried out to broaden the substrate specificity of Sbv333-ATA. The mutant W89A showed the highest activity toward bulky amines as substrates, such as the diaromatic compound 1,2-diphenylethylamine. The 3D structures of the holo and inhibitor gabaculine bound forms of native Sbv333-ATA, and holo W89A and F61C mutants were determined at high resolutions of 1.49, 1.24, and 1.31 (both mutants) Å, respectively. These structures were important for revealing further details of the active site binding pockets of the Sbv333-ATA and its mechanism.</p><p>• <i>Sbv333-ATA is a highly thermostable transaminase with a broad substrate scope.</i></p><p>• <i>Sbv333-ATA remains active in various organic cosolvents and biphasic systems.</i></p><p>• <i>Mutant W89A expands substrate range to accept bulky diaromatic amines.</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"109 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00253-025-13536-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832197","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":"Impact of specific productivity and operation mode upon the biophysical properties of HIV-1 Gag-based virus-like particles","authors":"Pol Pérez-Rubio,&nbsp;Elianet Lorenzo Romero,&nbsp;Josefina Casas,&nbsp;Andy Díaz-Maneh,&nbsp;Francesc Gòdia,&nbsp;Laura Cervera,&nbsp;Jesús Lavado-García","doi":"10.1007/s00253-025-13560-9","DOIUrl":"10.1007/s00253-025-13560-9","url":null,"abstract":"<p>Virus-like particles (VLPs) are non-infective vaccine candidates that have gained interest given their natural ability to elicit strong immune responses. Particularly, HIV-1 Gag-based VLPs are one of the most described platforms for vaccine development, provided their ability for successful pseudotyping either by genetic engineering or click chemistry. When Gag polyprotein is recombinantly expressed, VLPs are naturally assembled in the vicinity of the cell membrane and then secreted by cell budding, taking part of the host cell membrane. Their properties are dependent upon the cell line and manufacturing method. Although great advancements toward the implementation of analytical methods have been made, VLP quality attributes are quite unclear whenever production is enhanced by metabolic engineering or process intensification strategies. This work offers a comparative study of VLP quality attributes upon transient gene expression (TGE) in HEK293 cell cultures operated in batch and perfusion mode. Moreover, the impact of specific productivity is also studied by ataxia telangiectasia mutated (ATM) gene silencing, which has been reported to enhance fourfold VLP production. A linear negative correlation was found between the ratio of Gag monomers/VLP and specific productivity. 3100 ± 100 monomers/VLP were obtained for the standard batch production, dropping to 1900 ± 100 and 800 ± 60 for the perfusion and batch ATM-knockdown conditions, respectively. Furthermore, functionalization rates were measured in terms of Cy5 per total particles (TP). Both perfusion-derived nanoparticles achieved functionalization rates of 2800 Cy5/TP. On the contrary, those nanoparticles produced in batch yielded functionalization rates below 1000 Cy5/TP. Moreover, a complete lipidome analysis revealed a relative decrease in the quantity of lipid/particle for all studied conditions in comparison to the standard batch production. Finally, all VLP samples were characterized to assess the impact of the differential physicochemical properties upon purification and stability rates.</p><p>• <i>VLP quality inversely correlates with Gag-specific productivity and operation mode.</i></p><p>• <i>Functionalization and lipid content drop with metabolic burden or ATM silencing.</i></p><p>• <i>Perfusion enables high VLP recovery and lyophilization with preserved morphology.</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"109 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12334472/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144803314","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":"Flo5-1 and Nrg1 are involved in reversible pH-dependent flocculation in Komagataella phaffii","authors":"Sonakshi De,&nbsp;Gerhard Stadlmayr,&nbsp;Corinna Rebnegger,&nbsp;Diethard Mattanovich,&nbsp;Brigitte Gasser","doi":"10.1007/s00253-025-13562-7","DOIUrl":"10.1007/s00253-025-13562-7","url":null,"abstract":"<p>The non-conventional yeast <i>Komagataella phaffii</i> (syn <i>Pichia pastoris</i>) is a well-established host for biotechnological production processes, especially for recombinant protein production. Such processes are mostly run at neutral or slightly acid pH values between pH 5.0 and 6.5, but <i>K. phaffii</i> can grow also at lower or higher pH. Strikingly, we found that <i>K. phaffii</i> displays pH-dependent flocculation at pH 4, which is reversible when the cells are shifted to higher or lower pH. Six members of the flocculin (<i>FLO</i>) gene family were differentially regulated at pH 4.0. Of these, Flo5-1 was revealed to be crucially involved in the pH-triggered flocculation behavior, as cells lacking this flocculin (<i>flo5-1Δ</i>) settled at a much faster rate in the sedimentation assays. The transcriptional regulator Nrg1 was identified to negatively regulate this process, and cells overexpressing <i>NRG1</i> do not show the pH-dependent flocculation phenotype. In contrast to the model yeast <i>Saccharomyces cerevisiae</i>, neither the flocculin Flo11 nor the transcriptional activator Flo8 are involved in pH-dependent flocculation, once again highlighting the importance of studying transcriptional regulation mechanisms in non-conventional yeasts.</p><p>• <i>Komagataella phaffii</i> <i>shows flocculation at pH 4, which is reversible at other pH</i>.</p><p>• <i>Six</i> <i>FLO</i> <i>genes are differentially expressed at low pH; flo5-1Δ flocculates stronger</i>.</p><p><i>• </i><i>K. phaffii</i> <i>Nrg1, but not Flo8, is involved in regulating pH-dependent flocculation</i>.</p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"109 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12321659/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144783359","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":"Genomic characterization and pre-clinical evaluation of a new polyvalent lytic Loughborough phage","authors":"Mahmoud M. Sherif,&nbsp;Neveen A. Abdelaziz,&nbsp;Sarra E. Saleh,&nbsp;Khaled M. Aboshanab","doi":"10.1007/s00253-025-13559-2","DOIUrl":"10.1007/s00253-025-13559-2","url":null,"abstract":"<p>Carbapenem-resistant <i>Acinetobacter baumannii</i> (CRAB) has become a critical concern that necessitates the development of novel antimicrobial approaches. One of the most promising innovative approaches for combating CRAB infections is using effective and lytic bacteriophages (phages), known as phage therapy. Therefore, we recovered and characterized a polyvalent lytic Salmonella_phage_VB_ST-SA173, producing lytic activity against 6 CRAB clinical isolates and 3 multidrug-resistant (MDR) <i>Salmonella</i> serovars. Throughout pH 2–10, and thermal stability at up to 60 °C, the phage maintained its stability and lytic activity against the tested isolates. The presence of a tailed phage with a characteristic prolate head and a contractile tail was detected by the transmission electron microscope (TEM). According to the Oxford nanopore sequencing data, the genome of Salmonella_phage_VB_ST-SA173 was 53,636 bp in size, contained 45.9% G + C, and had 53 opening reading frames (ORFs). According to the TEM, ORFs, and BLASTn analysis findings, it was proved that the Salmonella_phage_VB_ST-SA173 belongs to the <i>Loughboroughvirus</i> genus. The efficacy of the phage-formulated Carbopol 940 hydrogel in wound healing was assessed preclinically in an infected burn wound animal model with a CRABa clinical isolate. The survival rate was enhanced in the phage-treated group compared to the untreated control groups. Histopathological analysis showed improved wound healing in the form of apparently healthy skin with apparently normal epidermal and dermis layers. In conclusion, depending on its in vitro and physicochemical traits, the phage-loaded hydrogel is expected to be a promising candidate for clinical trials against human CRAB-related skin infections.</p><p>•<i> A polyvalent Loughboroughvirus phage showed lytic activity against CRAB and Salmonella serovars.</i></p><p>•<i> The phage showed stability at a wide range of pH and temperature.</i></p><p>•<i> The phage hydrogel enhanced healing in the burn-wound animal model infected with CRABa.</i>\u0000</p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"109 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12317907/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144768330","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":"Probiotic potential and antimicrobial efficacy of a dairy isolate, Enterococcus faecium MBBL3","authors":"Naim Siddique,&nbsp;Md. Morshedur Rahman,&nbsp;Soharth Hasnat,&nbsp;Kh. Yeashir Arafat,&nbsp;A. N. M. Aminoor Rahman,&nbsp;Anup Kumar Talukder,&nbsp;Md Robiul Karim,&nbsp;Ziban Chandra Das,&nbsp;Tofazzal Islam,&nbsp;M. Nazmul Hoque","doi":"10.1007/s00253-025-13558-3","DOIUrl":"10.1007/s00253-025-13558-3","url":null,"abstract":"<div><p><i>Enterococcus faecium</i> is a promising probiotic with potential antimicrobial effects. This study aimed to evaluate the probiotic and antimicrobial properties of <i>E. faecium</i> MBBL3, isolated from healthy cow milk, against bovine mastitis pathogens <i>Klebsiella pneumoniae</i> MBBL2 (<i>Kp</i> MBBL2) and <i>Escherichia coli</i> MBBL4 (<i>Ec</i> MBBL4), using comprehensive genomic and functional analyses. The genome assembly and functional annotations of MBBL3 unveiled many important probiotic traits, and comparative genomic analysis demonstrated its high degree of genetic similarity with other <i>Enterococcus</i> strains. MBBL3 exhibited the ability to ferment a diverse range of carbohydrates and possessed 76 genes linked to carbohydrate-active enzyme, including five key CAZy families with potential antimicrobial activity. Additionally, MBBL3 harbored genes essential for bile salt and acid tolerance, stress resistance, and surface adhesion. Furthermore, MBBL3 was found to harbor gene clusters encoding secondary metabolites with antimicrobial potentials. Safety evaluations revealed a low pathogenic potential, while <i>in-vitro</i> assays demonstrated antibiotic susceptibility and a reduction in the growth of <i>Kp</i> MBBL2 and <i>Ec</i> MBBL4, respectively. It's bacteriocin Enterolysin_A exhibited strong molecular interactions with virulence-associated proteins of the mastitis pathogens. Thus, the promising probiotic potential and antimicrobial activity of <i>E. faecium</i> MBBL3, particularly against mastitis-related pathogens coupled with its safety profile, render it a promising candidate for further investigation.</p></div>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"109 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12316730/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144759017","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":"Genomic and secretomic analyses of Blastobotrys yeasts reveal key xylanases for biomass decomposition","authors":"Jonas Ravn,&nbsp;Amanda S. Ristinmaa,&nbsp;Scott Mazurkewich,&nbsp;Guilherme B. Dias,&nbsp;Johan Larsbrink,&nbsp;Cecilia Geijer","doi":"10.1007/s00253-025-13556-5","DOIUrl":"10.1007/s00253-025-13556-5","url":null,"abstract":"<p>Xylanolytic enzyme systems in ascomycetous yeasts remain underexplored, despite the presence of yeasts in various xylan-rich ecological niches. In this study, we investigated the secreted xylanolytic machineries of three <i>Blastobotrys</i> species—<i>B. mokoenaii</i>, <i>B. illinoisensis</i>, and <i>B. malaysiensis</i>—by integrating genome annotation, bioinformatics, and secretome analyses of cultures grown on beechwood glucuronoxylan. Our findings demonstrate that these yeasts effectively hydrolyze xylan through the secretion of xylanases from the glycoside hydrolase (GH) family 11, which play a central role in cleaving the xylan backbone. Additionally, the yeasts produce a diverse array of other CAZymes, including members of GH families 3, 5, and 67, with putative roles in xylan degradation. We also report on the heterologous expression and functional characterization of the GH30_7 xylanase <i>Bm</i>Xyn30A from <i>B. mokoenaii</i>, which exhibits both glucuronoxylanase and xylobiohydrolase activities. We demonstrate additive effects between GH family 30 <i>Bm</i>Xyn30A and GH family 11 <i>Bm</i>Xyn11A during the hydrolysis of beechwood glucuronoxylan, where the enzymes exhibit complementary roles that enhance the deconstruction of this complex hemicellulose substrate. These findings broaden our understanding of the xylanolytic systems in yeasts and underscore the potential of <i>Blastobotrys</i> species as cell factories and natural xylanase producers. The enzymes they produce hold promise for biorefining applications, enabling efficient utilization of renewable xylan-rich plant biomass resources.</p><p>•<i> Extracellular GH11 xylanases dominate glucuronoxylan degradation in Blastobotrys yeasts.</i></p><p>•<i> Yeast GH30_7 enzyme shows multifaceted activity, supporting complex xylan breakdown.</i></p><p>•<i> Blastobotrys yeasts show promise as cell factories for industrial biotechnology applications.</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"109 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12316802/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144759016","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":"Immobilized β-galactosidase BgaC from Bifidobacterium adolescentis retains stability and activity during repeated cycles of use","authors":"Daniel Mehabie Mulualem,&nbsp;Orla Dwan,&nbsp;Michelle Kilcoyne,&nbsp;Conor O’Byrne,&nbsp;Aoife Boyd","doi":"10.1007/s00253-025-13564-5","DOIUrl":"10.1007/s00253-025-13564-5","url":null,"abstract":"<p>β-Galactosidase enzymes catalyze the hydrolysis of terminal non-reducing β-D-galactose residues in β-galactosides. These enzymes are important in producing lactose-free dairy products, reducing the lactose content of whey in dairy products, and for production of galactooligosaccharides (GOS) as prebiotic additives to infant formula. To use β-galactosidases in industrial settings, enzyme immobilization procedures are used to enhance their activity and stability and to minimize enzyme quantities and cost. In this study, recombinant <i>Bifidobacterium adolescentis</i> β-galactosidase BgaC was immobilized in calcium alginate and gelatin cross-linked with glutaraldehyde. The kinetic parameters and stability properties of immobilized BgaC were characterized in comparison with free soluble enzyme. The <i>K</i>_M for immobilized BgaC using ortho-nitrophenyl-β-galactoside (ONPG) was 810 ± 220 μM and the <i>K</i>_M of free BgaC was 2500 ± 3 μM. The <i>k</i>_cat and <i>k</i>_cat<i>/</i><i>K</i>_M of immobilized BgaC were 802 s⁻¹ and 990 s⁻¹ mM⁻¹, respectively, compared to <i>k</i>_cat and <i>k</i>_cat<i>/</i><i>K</i>_M values of 209 s⁻¹ and 84 s⁻¹ mM⁻¹, respectively, for free BgaC. Immobilized BgaC β-galactosidase was active at all tested pH (pH 4–10), while the free enzyme had decreased activity at pH &lt; 5.5 and &gt; 8.0. The immobilized enzyme had optimum activity at 40 °C, while the free enzyme was most active at 37 °C. In addition, immobilization enhanced acidic pH and temperature stability compared to the free enzyme. Reutilization of the BgaC beads was assessed and the enzyme maintained 69% activity after 12 rounds of reutilization. Therefore, the enhanced performance properties of immobilized BgaC make it a promising candidate for industrial applications.</p><p>• <i>Bifidobacterium adolescentis β-galactosidase BgaC was successfully immobilized</i></p><p>• <i>Immobilized BgaC has enhanced enzymatic activity and stability and allows recycling</i></p><p>• <i>Sustained activity of immobilized BgaC is advantageous for industrial applications</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"109 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12310786/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144740985","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":"A novel acidic laminarinase derived from Jermuk hot spring metagenome","authors":"Ani Paloyan,&nbsp;Tigran Soghomonyan,&nbsp;Mariam Karapetyan,&nbsp;Hasmik Grigoryan,&nbsp;Anna Krüger,&nbsp;Fiona Cuskin,&nbsp;Jon Marles-Wright,&nbsp;Christin Burkhardt,&nbsp;Garabed Antranikian","doi":"10.1007/s00253-025-13557-4","DOIUrl":"10.1007/s00253-025-13557-4","url":null,"abstract":"<p>Laminarinase, an enzyme with a specific affinity for laminarin—a complex polysaccharide found in the cell walls of brown algae and select marine organisms—was investigated in this study. We cloned and characterized a gene encoding a putative glycoside hydrolase family 16 (GH16) laminarinase derived from the Jermuk hot spring metagenome. The resulting product, named Jermuk-LamM, represents a novel 1,3-β-<span>d</span>-glucanase with 48.1% amino acid sequence similarity to previously characterized GH16 family members catalogued in the NCBI database. To date, this stands as the sole described endo-1,3-β-<span>d</span>-glucanase from the Fidelibacterota phylum, which was recently reclassified from <i>Marinimicrobia</i>. Jermuk-LamM, identified as an acidic laminarinase, exhibits optimal enzymatic activity at pH 5.0 and a temperature of 55 °C, maintaining its function for a duration of at least 7 h. Jermuk-LamM is an enzyme that efficiently hydrolyzes both soluble and insoluble (1,3)-β-<span>d</span>-glucans, as well as (1,3;1,4)-β-<span>d</span>-glucans, with a marked preference for laminarin. This enzymatic activity facilitates the valorization of macroalgal biomass by predominantly producing monosaccharides and disaccharides. These hydrolysis products can subsequently be converted into energy carriers such as alcohol, methane, and hydrogen. The enzyme’s specific activities, coupled with its resistance to various additives, render Jermuk-LamM a promising candidate for various industrial applications, encompassing the realms of biofuel and pharmaceutical production.</p><p>• <i>Jermuk hot springs have significant potential as a source of novel enzymes</i>.</p><p>• <i>Jermuk-LamM has less than 50% amino acid similarity to known enzymes</i>.</p><p>• <i>It is the first enzyme characterized from the Fidelibacterota phylum</i>.</p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"109 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12296878/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144717280","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":"Identifying promoters to enhance heterologous gene expression in recombinant Saccharomyces cerevisiae strains cultivated on non-native substrates","authors":"Jordan Fortuin,&nbsp;Riaan den Haan","doi":"10.1007/s00253-025-13563-6","DOIUrl":"10.1007/s00253-025-13563-6","url":null,"abstract":"<p>Efficient bioconversion of lignocellulosic biomass (LCB) to ethanol by <i>Saccharomyces cerevisiae</i> requires its engineering to express heterologous enzymes at titres high enough to make significant impacts on industrial consolidated bioprocessing (CBP). Promoters are required for this purpose, but are reportedly influenced by various environmental factors as well as the protein specific nature of expression, warranting the need for assessment under the conditions for which they are intended. Heterologous xylosidase- and xylanase-encoding genes (<i>xln43_SED1</i> and <i>xyn2</i>) were individually cloned under transcriptional control of the <i>SED1</i>_P and <i>TDH3</i>_P promoters, and <i>DIT1</i>_T terminator, and integrated into the genome of an a <i>S. cerevisiae</i> strain engineered for xylose utilization. Enzymatic assays were used to quantify the performance of the promoters when strains were cultivated on glucose (aerobically and micro-aerobically) and xylose. Additional strains containing both <i>xln43_SED1</i> and <i>xyn2</i> under different promoter combinations were then used to allow direct fermentation of beechwood xylan to ethanol in a CBP. The <i>SED1</i>_P/<i>DIT1</i>_T and <i>TDH3</i>_P/<i>DIT1</i>_T combinations significantly outperformed the benchmark <i>ENO1</i>_P/T under all of the tested cultivation conditions, as well as with regard to growth trials on non-native substrates (xylo-oligosaccharides/XOS and beechwood xylan) and fermentations of beechwood xylan to ethanol. Overall, <i>TDH3</i>_P was the best-performing promoter. This study demonstrates that heterologous metabolic pathways and CBP can be significantly enhanced by employing carefully selected promoters tailored to specific conditions.</p><p>• <i>Promoters are unpredictable and must be tested under their intended conditions.</i></p><p>• <i>TDH3</i>_<i>P</i>, <i>SED1</i>_<i>P</i>, <i>and DIT1</i>_<i>T</i> <i>were effective in enhancing heterologous xylanase activity.</i></p><p>• <i>Optimized xylanolytic enzyme expression improved CBP of xylan to ethanol.</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"109 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12296805/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144717281","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}