Food Technology and Biotechnology最新文献

{"title":"Date Fruits and Their Products for Almond Beverage Fortification: Assessment of Beverages and Resulting Residues.","authors":"Malek Ben Zid, Nesrine Rokbeni, Nouha M'hiri, Moncef Chouaibi, Nahla Zghonda, Nourhene Boudhrioua","doi":"10.17113/ftb.64.02.26.9031","DOIUrl":"10.17113/ftb.64.02.26.9031","url":null,"abstract":"<p><strong>Research background: </strong>The shift towards plant-based beverages, particularly almond drinks, has increased the need to develop innovative products using fruits and herbal extracts to improve their nutritional and sensory properties. In this study, date palm fruits, Deglet Nour variety (tamr stage) and Besser Helou variety (khalal stage), and two Deglet Nour-derived products (date powder and syrup) were evaluated as fortifying ingredients in almond drinks. The antioxidant and nutritional properties of the recovered solid residues were also evaluated.</p><p><strong>Experimental approach: </strong>The beverage-making process involved grinding blanched almonds into flour (<i>w</i>=12 %), mixing with date products (<i>w</i>=20 %), water extraction, filtration, and pasteurisation. Proximate composition, physicochemical properties, phenolic profiles (liquid chromatography-high resolution electrospray ionization mass spectrometry), and antioxidant activity of the raw ingredients, beverages, and recovered residues were analysed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Fe(III) reducing antioxidant power (FRAP) assays. In addition, physical stability, rheological behaviour, and sensory attributes of the beverages were evaluated using descriptive analysis and acceptability tests.</p><p><strong>Results and conclusions: </strong>The addition of date-based ingredients to almonds significantly reduced the extraction yields of beverages, with the reduction being least significant in syrup, moderate in Deglet Nour and Besser Helou varieties, and most significant in date powder. Combining almonds with any form of dates significantly increased carbohydrate and ash mass fraction, energy value and antioxidant activity of beverages, as confirmed by both FRAP and DPPH assays. Phenolics previously present in almonds and dates were found to multiply, while new ones appeared in both drinks and residues, such as caffeic acid. A distinctive rheological profile was observed in beverages fortified with Deglet Nour, date syrup and date powder, characterised by shear thickening at low shear rates and a transition to shear thinning at higher shear rates. Sensory evaluations of enriched drinks revealed that dates provided new colour shades, increased sweetness and mouthfeel viscosity, and improved almond taste perception. Date powder-based drinks received the highest overall acceptability rating, while syrup-based drinks received the lowest. Combining date ingredients with almonds reduced the fat and protein mass fraction of residues while increasing carbohydrate mass fraction. Quinic acid and quercetin were the prevalent phenolic acids and flavonoids in almond residue, while caffeic acid and luteolin were the primary compounds in date-based residues.</p><p><strong>Novelty and scientific contribution: </strong>This study presents the first comprehensive evaluation of the nutritional, rheological, antioxidant and sensory properties of almond beverages fortifi","PeriodicalId":12400,"journal":{"name":"Food Technology and Biotechnology","volume":"64 2","pages":"205-221"},"PeriodicalIF":2.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13282974/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148293980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Near-Infrared Spectroscopy for Rapid Determination of Physicochemical Properties of Fermented Fish Sauce ('Nam Pla-Ra').","authors":"Sunee Jungtheerapanich, Kraireuk Ngowsuwan, Sumaporn Kasemsumran","doi":"10.17113/ftb.64.02.26.8998","DOIUrl":"10.17113/ftb.64.02.26.8998","url":null,"abstract":"<p><strong>Research background: </strong>Thai community product quality standards have been established for nam pla-ra, which require at least 4 % protein and 12 % sodium chloride. Determining the protein and NaCl contents requires chemicals and is time-consuming. In addition to reporting protein and salt content, other quality controls must also be carried out. Thus, the objective of this research is to develop predictive models for the determination of physicochemical properties of nam pla-ra using near-infrared spectroscopy (NIRS) for fast and simultaneous multi-parameter prediction.</p><p><strong>Experimental approach: </strong>The physicochemical values of commercially available fermented fish sauce ('nam pla-ra' in Thai) were evaluated to develop predictive models for determining physicochemical values and developing models to categorize samples. The model was developed and tested based on the seven parameters: total soluble solids (TSS), pH, <i>L*</i>, <i>a*</i>, <i>b*</i>, NaCl and protein content.</p><p><strong>Results and conclusions: </strong>The predictive models for pH and colour (<i>L*</i>, <i>a*</i>, <i>b*</i>) could be used for screening, based on their coefficients of determination (R²=0.73-0.81; SEP=0.15-0.94). The model for determining protein content (R²=0.86; SEP=0.44) is suitable for screening, routine quality control, and research applications. In contrast, the TSS and NaCl models (R²=0.97-0.98; SEP=0.41-0.61) demonstrate high predictive performance and can be reliably applied to all analytical tasks, including screening, routine quality control, and research purposes. The physicochemical properties of nam pla-ra could be predicted accurately using TSS, colour (<i>L*</i>, <i>a*</i>, <i>b*</i>), NaCl, and protein content. There was no significant (p>0.05) difference between the quality values obtained from the predictive model and the reference method, except for the pH value.</p><p><strong>Novelty and scientific contribution: </strong>NIRS showed potential in predicting the physicochemical properties of nam pla-ra using TSS and colour (<i>L*</i>, <i>a*</i>, <i>b*</i>) in the range 1000-2500 nm, and NaCl and protein contents in the selected ranges 1000-1889 and 2031-2408 nm, respectively. Furthermore, these findings demonstrate the potential of NIRS as a rapid, non-destructive, environmentally friendly and reliable analytical tool for determining the properties of nam pla-ra. NIRS can contribute to ensuring product consistency and facilitating standardisation in the fermented fish sauce industry. Such applications enhance food safety and consumer confidence.</p>","PeriodicalId":12400,"journal":{"name":"Food Technology and Biotechnology","volume":"64 2","pages":"140-148"},"PeriodicalIF":2.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13275098/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148276816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing Yeast Surface Display: UPR, ERAD, and ER Dynamics in Recombinant Protein Production.","authors":"Tea Martinić Cezar, Antonia Paić, Bojan Žunar, Igor Stuparević, Vladimir Mrša, Renata Teparić","doi":"10.17113/ftb.64.01.26.8764","DOIUrl":"10.17113/ftb.64.01.26.8764","url":null,"abstract":"<p><p>Over the past two decades, the display of various recombinant proteins on the surfaces of microorganisms, particularly yeast, has garnered significant research attention. This method is rapid, simple and cost-effective, combining the biosynthesis and secretion of recombinant proteins with their immobilization on the host cell surface. Proteins synthesized using this technique are transported to the cell surface and incorporated into the cell wall through mild, native processes, avoiding aggressive chemical immobilization methods that often lead to a loss of physiological activity. Surface-displayed proteins are generally more stable and resistant to environmental changes than those in a solution. Depending on the promoter used, cells can continuously renew the recombinant protein on their surface or express it only under certain conditions. Additionally, cells carrying surface-displayed enzymes can be easily separated from the reaction mixture and reused multiple times. These enzymes can also catalyze reactions with substrates that cannot enter the cells, facilitating extracellular synthesis and simplifying product purification. However, the main obstacle to the industrial application of this method is often low efficiency, resulting in limited amounts of displayed protein. The efficiency depends on the processes that the protein undergoes on its way to the cell surface, following the same pathway as native secretory proteins: synthesis in the endoplasmic reticulum (ER), transport to the Golgi, and delivery to the cell surface <i>via</i> transport vesicles. Large amounts of secretory proteins can overload the ER, triggering the unfolded protein response (UPR) and endoplasmic reticulum-associated degradation (ERAD). Despite significant improvements for some proteins, a universal system for all recombinant proteins has yet to be developed. However, the complexity of protein processing and secretion pathways suggests that a single system improving productivity for all recombinant proteins is unlikely. Instead, several optimized systems tailored to specific protein structures may be necessary. This article provides an overview of the processes that recombinant proteins intended for surface display undergo on their way to the cell surface in the endoplasmic reticulum and represent a crucial bottleneck for the successful immobilization of recombinant proteins at the cell surface.</p>","PeriodicalId":12400,"journal":{"name":"Food Technology and Biotechnology","volume":"64 1","pages":"4-19"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12892411/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146178870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual-Target Bioprocessing Using Oleaginous Microorganisms: Converting Food Waste into Lipids and Biopolymers.","authors":"Zahra Montazer, Kianoush Khosravi-Darani","doi":"10.17113/ftb.64.01.26.9268","DOIUrl":"10.17113/ftb.64.01.26.9268","url":null,"abstract":"<p><p>The increasing demand for sustainable alternatives to fossil-derived fuels and plastics has intensified research into microbial platforms that can convert abundant waste resources into valuable products. This review focuses on the emerging field of dual-target bioprocessing using oleaginous microorganisms to produce single-cell oils (SCOs) and polyhydroxyalkanoates (PHAs) from food waste. We discuss key microbial strains, their metabolic pathways, co-production capabilities and substrate preferences. Emphasis is placed on the use of food waste as a low-cost and carbon-rich feedstock, thereby enhancing both economic feasibility and environmental sustainability. We also analyze integrated bioprocess strategies developed to overcome existing challenges, such as yield optimization and metabolic bottlenecks. This dual-production platform addresses the principles of circular economy, facilitating the conversion of waste into high-value bioproducts.</p>","PeriodicalId":12400,"journal":{"name":"Food Technology and Biotechnology","volume":"64 1","pages":"30-38"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12892409/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146178840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modern Food Systems Challenged by Food Safety Culture.","authors":"Mojca Jevšnik Podlesnik, Peter Raspor","doi":"10.17113/ftb.64.01.26.9508","DOIUrl":"10.17113/ftb.64.01.26.9508","url":null,"abstract":"<p><p>Despite decades of regulatory development, standardized food safety management systems, and technological advances, foodborne outbreaks, recalls, and food fraud continue to pose significant public health and societal challenges. These persistent failures increasingly reveal systemic vulnerabilities that deficiencies in legislation or formal control mechanisms alone cannot explain. Instead, they highlight the critical role of human behaviour, organizational culture, and socio-technical interactions within modern, complex agrifood networks. Food safety culture has therefore emerged as a key determinant of food safety performance, linking regulatory frameworks with everyday practices in food establishments. While HACCP-based systems clearly define procedures and responsibilities, their effectiveness is limited when behavioural consistency, leadership commitment, communication, and resource availability are weak. Research consistently shows that even well-designed systems are insufficiently monitored when organizational alignment and behavioural adherence are lacking, allowing deviations from safe practices to persist. Contemporary approaches move beyond compliance-driven models towards cultural transformation, emphasizing leadership engagement, effective risk communication, learning-oriented environments, and evidence-based behavioural interventions. Increasingly, digital tools and real-time monitoring systems support this transition by strengthening feedback, transparency, and adaptive risk management across food systems. Strengthening food safety culture therefore requires coordinated, multi-level action that integrates governance, technology and human-oriented approaches. Such transformation is essential not only for improving food safety outcomes but also for protecting public health, maintaining consumer trust and enhancing the long-term resilience and sustainability of modern food systems.</p>","PeriodicalId":12400,"journal":{"name":"Food Technology and Biotechnology","volume":"64 1","pages":"81-96"},"PeriodicalIF":2.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13034769/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147591136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial Activity of Bee Pollen: Influence of Botanical Origin and Processing.","authors":"Tajda Lukman, Sonja Smole Možina","doi":"10.17113/ftb.64.01.26.9421","DOIUrl":"10.17113/ftb.64.01.26.9421","url":null,"abstract":"<p><p>Bee pollen is a nutrient-rich bee product and natural food supplement that contains proteins, vitamins, minerals and bioactive compounds, offering antioxidant, anti-inflammatory, immunostimulatory and antimicrobial activity. Numerous studies have confirmed the <i>in vitro</i> antimicrobial activity of both polyfloral and monofloral bee pollen. Monofloral bee pollen had a more stable chemical composition and more consistent sensory and biochemical properties, making it more suitable for various applications. This has led to a growing number of studies investigating its antimicrobial potential. Antimicrobial activity of bee pollen is influenced by natural factors such as the botanical and geographical origin, seasonal variation and beekeeping practices. The outcomes of <i>in vitro</i> testing also depend on choices related to extract preparation, solvent type, microbial strains and the method employed to measure antimicrobial activity. Another challenge is the limited bioavailability of bioactive compounds, restricted by the degradation-resistant outer layer of bee pollen, named the exine. The wall can be partially disrupted through processing methods that break it and enhance its nutritional and functional properties. This review provides a comprehensive overview of published studies on the antimicrobial activity of monofloral bee pollen. It summarizes the most frequently investigated botanical species and bacterial strains, highlighting those with the most promising antimicrobial results. Additionally, it examines the processing methods of pollen, comparing their effectiveness and the changes in antimicrobial activity before and after processing. The review identifies the plant species, solvents and methods that yield strong antimicrobial activity, emphasizing their potential in the broader effort to standardize high quality parameters for bee pollen.</p>","PeriodicalId":12400,"journal":{"name":"Food Technology and Biotechnology","volume":"64 1","pages":"67-80"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12892412/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146178846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulating Complex Secondary Metabolism in <i>Streptomyces rimosus</i> by Targeted Genome Engineering.","authors":"Martina Avbelj, Lucija Slemc, Alen Pšeničnik, Špela Zver, Anastasija Lazova, Kristina Mervič, Khan Mohammad Sarim, Maja Paš, Antonio Starčević, Martin Šala, Miha Tome, Dušica Vujaklija, Hrvoje Petković","doi":"10.17113/ftb.64.01.26.9441","DOIUrl":"10.17113/ftb.64.01.26.9441","url":null,"abstract":"<p><strong>Research background: </strong>Numerous biosynthetic gene clusters (BGCs) encoding unknown structures have been discovered in the genomes of diverse microorganisms, representing a potentially rich source of novel natural products. However, most of the identified BGCs do not seem to be active, since we cannot detect any corresponding metabolites. Therefore, a better understanding of the regulation and biosynthesis of secondary metabolites encoded by these so-called 'silent' BGCs is of great importance.</p><p><strong>Experimental approach: </strong>We conducted a bioinformatic analysis of the <i>Streptomyces rimosus</i> ATCC 10970 strain, a producer of the antibiotic oxytetracycline, focusing on the expression of identified BGCs. We then reviewed experimentally identified compounds and putative structures predicted from genome data and similarity to known metabolites. We analysed available data on the regulation of two major metabolites - oxytetracycline and rimocidin, and experimentally evaluated the effect of the deletion of two oxytetracycline-competing pathways. Finally, we evaluated the effect of overexpressing BGC encoding the biosynthesis of the carotenoid isorenieratene, which cannot be detected in the culture of the native strain.</p><p><strong>Results and conclusions: </strong>We identified 48 BGCs in the genome of <i>Streptomyces rimosus</i> ATCC 10970. However, only about 15 structures were predicted or identified in the culture of this strain. Transcriptional analysis of identified BGCs demonstrated a very high variability in expression strength. Interestingly, around 30 % of BGCs were 'silent'. <i>In trans</i> overexpression of one such silent BGC, encoding the biosynthesis of the carotenoid isorenieratene resulted in strong production of this metabolite, suggesting that silent BGCs are likely still functional. We also demonstrated that BGCs encoding two major metabolites, oxytetracycline and rimocidin, both derived from malonyl-coenzyme A (malonyl-CoA), are not competitive pathways. Surprisingly, deletion of one silent BGC, also derived from malonyl-CoA, has a very strong effect on the biosynthesis of oxytetracycline.</p><p><strong>Novelty and scientific contribution: </strong>We observed that the expression strength of genes from BGCs identified in <i>Streptomyces rimosus</i> does not correspond to the experimental data obtained from the engineered strains, suggesting much more complex regulatory mechanisms than previously thought. Engineered <i>Streptomyces rimosus</i> host strains thus represent a very good model system to study the expression of 'silent' BGCs.</p>","PeriodicalId":12400,"journal":{"name":"Food Technology and Biotechnology","volume":"64 1","pages":"97-112"},"PeriodicalIF":2.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13098539/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147766775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sourcing Vanillin <i>via</i> Fermentative Biotechnology.","authors":"Stefanie Schmid, Beate Berchtold, Harald Pichler","doi":"10.17113/ftb.64.01.26.9445","DOIUrl":"10.17113/ftb.64.01.26.9445","url":null,"abstract":"<p><p>Less than 1 % of the annual worldwide consumption of vanillin can be met by extracting the aromatic compound from vanilla (<i>Vanilla planifolia</i>) pods. For 150 years, vanillin has also been derived through chemical synthesis, which remains the main source (>80 %) of vanillin today, despite growing environmental concerns due to considerable chemical waste disposal issues. 'Natural' vanillin is in high demand for flavour and fragrance applications. Thus, biotechnological routes using an array of recombinant hosts have been devised to obtain vanillin through fermentation of natural precursors, <i>e.g</i>. ferulic acid, (iso)eugenol and glucose. These processes, often classical biotransformations, result in 'natural' vanillin according to European and US legislation. A significant technical hurdle in fully fermentative routes is vanillin toxicity, which impairs cellular proliferation at relatively low, <i>i.e</i>. commercially uninteresting, vanillin concentrations. In addition to adopting the plant-derived solution, <i>i.e</i>. product glycosylation, to sequester and store vanillin glycosides, sophisticated <i>in situ</i> product removal strategies have been used to obtain industrially relevant amounts of 'natural' vanillin.</p>","PeriodicalId":12400,"journal":{"name":"Food Technology and Biotechnology","volume":"64 1","pages":"126-136"},"PeriodicalIF":2.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13047440/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147622335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bridging Yeast Biochemistry and Biotechnological Innovation: A Tribute to Professor Emeritus Vladimir Mrša.","authors":"Igor Stuparević, Peter Raspor, Renata Teparić","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":12400,"journal":{"name":"Food Technology and Biotechnology","volume":"64 1","pages":"2-3"},"PeriodicalIF":2.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13061161/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147644700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The <i>Schizosaccharomyces pombe</i> Glycosyltransferase Gmh5 is a Functional Homologue of the α-1,6-Mannosyltransferase Mnn10 Crucial for N-Glycan Processing.","authors":"Mark Lommel, Franziska Hutzler, Lina Siukstaite, Klemens Wild, Antonija Grbavac, Irmgard Sinning, Sabine Strahl","doi":"10.17113/ftb.64.01.26.9195","DOIUrl":"10.17113/ftb.64.01.26.9195","url":null,"abstract":"<p><strong>Research background: </strong>Glycosyltransferases represent a large and diverse family of enzymes that catalyze the transfer of sugar residues to proteins and lipids, thereby regulating essential cellular processes such as protein quality control and cell wall biosynthesis. In yeast, protein O-mannosyltransferases and other glycosyltransferases are crucial for maintaining cell wall integrity. While the functions of many of these enzymes are well characterized, the role of some of them, such as Gmh5p, remains unknown. This study aims to elucidate the function of Gmh5p, a previously uncharacterized member of the GT34 glycosyltransferase family, in the context of protein and cell wall biosynthesis in <i>Schizosaccharomyces pombe</i>.</p><p><strong>Experimental approach: </strong>To identify proteins and pathways compensating for reduced O-mannosylation, we performed a genetic screening for multicopy suppressors in a conditional lethal nmt81-<i>oma2</i> ⁺ mutant background. The enzymatic activity of Gmh5p was biochemically characterized, and its functional homology to known mannosyltransferases was assessed through complementation experiments in <i>Saccharomyces cerevisiae</i>. In addition, the N-glycosylation status of model substrates was analyzed in gmh5Δ mutant strains.</p><p><strong>Results and conclusions: </strong>Gmh5p was identified as a suppressor of O-mannosylation defects. Contrary to its predicted function, Gmh5p did not exhibit α-1,2-galactosyltransferase activity but instead showed mannosyltransferase activity. Expression of <i>gmh5</i> ⁺ in <i>S. cerevisiae</i> mnn10Δ mutants restored hygromycin tolerance to near wild-type levels. Furthermore, N-glycosylation of model substrates was reduced in gmh5Δ mutants. These results demonstrate that Gmh5p is a mannosyltransferase involved in the outer chain elongation of N-linked glycans and functions as a homologue of Mnn10p.</p><p><strong>Novelty and scientific contribution: </strong>This study provides the first functional characterization of Gmh5p as a mannosyltransferase of the GT34 family and demonstrates its role in N-glycan biosynthesis. Our findings expand the current understanding of the diversity and specificity of glycosyltransferases in eukaryotes and highlight their importance in cell wall biology.</p>","PeriodicalId":12400,"journal":{"name":"Food Technology and Biotechnology","volume":"64 1","pages":"39-52"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12892413/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146178899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}