Sara Lupacchini, Ron Stauder, Franz Opel, Stephan Klähn, Andreas Schmid, Bruno Bühler, Jörg Toepel
{"title":"Co-expression of auxiliary genes enhances the activity of a heterologous O2-tolerant hydrogenase in the cyanobacterium Synechocystis sp. PCC 6803","authors":"Sara Lupacchini, Ron Stauder, Franz Opel, Stephan Klähn, Andreas Schmid, Bruno Bühler, Jörg Toepel","doi":"10.1186/s13068-025-02634-5","DOIUrl":"10.1186/s13068-025-02634-5","url":null,"abstract":"<div><p>Cyanobacteria bear great biotechnological potential as photosynthetic cell factories. In particular, hydrogenases are promising with respect to light-driven H<sub>2</sub> production as well as H<sub>2</sub>-driven redox biocatalysis. Their utilization relies on effective strain design as well as a balanced synthesis and maturation of heterologous enzymes. In a previous study, the soluble O<sub>2</sub>-tolerant hydrogenase complex from <i>Cupriavidus necator </i>(<i>Cn</i>SH) could be introduced into the model cyanobacterium <i>Synechocystis</i> sp. PCC 6803. Due to its O<sub>2</sub>-tolerance, it was indeed active under photoautotrophic growth conditions. However, the specific activity was rather low indicating that further engineering is required, for which we followed a two-step approach. First, we optimized the <i>Cn</i>SH multigene expression in <i>Synechocystis</i> by applying different regulatory elements. Although corresponding protein levels and specific <i>Cn</i>SH activity increased, the apparent rise in enzyme levels did not fully translate into activity increase. Second, the entire set of <i>hyp</i> genes, encoding <i>Cn</i>SH maturases, was co-expressed in <i>Synechocystis</i> to investigate, if <i>Cn</i>SH maturation was limiting. Indeed, the native <i>Cn</i>SH maturation apparatus promoted functional <i>Cn</i>SH synthesis, enabling a threefold higher H<sub>2</sub> oxidation activity compared to the parental strain. Our results suggest that a fine balance between heterologous hydrogenase and maturase expression is required to ensure high specific activity over an extended time period.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02634-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Efficient production of salicylic acid through CmeR-PcmeO biosensor-assisted multiplexing pathway optimization in Escherichia coli","authors":"Kai Wang, Xuewei Pan, Taowei Yang, Zhiming Rao","doi":"10.1186/s13068-025-02637-2","DOIUrl":"10.1186/s13068-025-02637-2","url":null,"abstract":"<div><p>To address the challenge of microbial tolerance in industrial biomanufacturing, we developed an adaptive evolution strategy for <i>Escherichia coli</i> W3110 to enhance its salicylic acid (SA) tolerance. Utilizing a CmeR-P<sub>cmeO</sub> biosensor-enabled high-throughput screening system, we isolated an SA-tolerant variant (W3110K-4) that exhibited a 2.3-fold increase in tolerance (from 0.9 to 2.1 g/L) and a 2.1-fold improvement in SA production (from 283 to 588.1 mg/L). Subsequently, the designed sensors were combined with multi-pathway sgRNA arrays to dynamically modulate the other three branched-chain acid derivatives, achieving a balance between biomass growth and rapid SA production in the adaptively evolved strain, resulting in a maximum SA yield of 1477.8 mg/L, which represents a 30% improvement over the non-evolved control strain W3110K-W2 (1138.2 mg/L) using the same metabolic strategy. Whole-genome sequencing revealed that adaptive mutations in genes such as <i>ducA</i>* and anti-drug resistance C2 mutation genes (<i>ymdA</i>*, <i>ymdB</i>*, <i>clsC</i>*, <i>csgB</i>*, <i>csgA</i>*, and <i>csgC</i>*) play a key role in enhancing SA tolerance and productivity. Notably, the evolved strain W3110K-4 exhibits significant resistance to bacteriophages, making it a promising candidate for large-scale SA fermentation. This work develops and expands the CmeR-P<sub>cmeO</sub> system, proposes new insights into improved strains through biosensor screening, guided multi-pathway metabolism, and adaptive evolution, and provides a paradigm for engineers to obtain engineered strains.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02637-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Elevated accumulation of lutein and zeaxanthin in a novel high-biomass yielding strain Dunaliella sp. ZP-1 obtained through EMS mutagenesis","authors":"Chenglong Liu, Danqiong Huang, Xinran Zhuo, Ying Luo, Junjie Zhou, Jinwei Feng, Xueer Wen, Zixin Liao, Runling Wu, Zhangli Hu, Sulin Lou, Hui Li","doi":"10.1186/s13068-025-02629-2","DOIUrl":"10.1186/s13068-025-02629-2","url":null,"abstract":"<div><h3>Background</h3><p><i>Dunaliella</i> microalgae, such as <i>Dunaliella salina</i> riching in β-carotene and <i>Dunaliella bardawil</i> rich in lutein and α-carotene, have been used in aquaculture, supplements, cosmetics, and feed industries. The genus <i>Dunaliella</i> is diverse; therefore, characterization of novel strains and isolation of new varieties through mutagenesis technology will promote natural carotenoid bioproduction.</p><h3>Results</h3><p>Salt stress test demonstrated that the newly isolated microalgae strain ZP-1 was a halotolerant strain. Morphology observation and molecular phylogeny analysis indicated that the unicellular green microalga ZP-1 was a member of the genus <i>Dunaliella</i>. Biomass of ZP-1 in RAM medium was up to 2.45 g/L, showing the advantage over other common <i>Dunaliella</i> microalgae in terms of yield. Furthermore, Ethyl methanesulfonate (EMS) mutant library was generated from this high-biomass strain, aiming to improve natural carotenoid productivity. A mutant strain was selected through morphology observation combining with carotenoid quantification by HPLC, which was nominated as <i>turn yellow dunaliella 4</i> (<i>tyd4</i>). The mutant <i>tyd4</i> displayed an increased lutein productivity by 28.55% and an increased zeaxanthin productivity by 22.19%. Biomass of <i>tyd4</i> was promoted by 17.40% through continuous culture under red light. Application of exogenous 1.0 μM melatonin on the mutant <i>tyd4</i> led to increased cell density and improved biomass.</p><h3>Conclusions</h3><p>Results in this study support that EMS mutagenesis is an effective breeding approach for further improvement of <i>Dunaliella</i> sp. ZP-1, which is a high-biomass microalgae exhibiting potential to overcome the bottleneck of low biomass of current commercial <i>Dunaliella</i> strains. The mutant <i>tyd4</i> had higher contents of both lutein and zeaxanthin, whose yield could be further elevated by red light and melatonin. This study provided new microalgae sources for scientific research and technical reference for the bioproduction of natural carotenoids.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02629-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Combining biosensor and metabolic network optimization strategies for enhanced l-threonine production in Escherichia coli","authors":"Zhenqiang Zhao, Rongshuai Zhu, Xuanping Shi, Fengyu Yang, Meijuan Xu, Minglong Shao, Rongzhen Zhang, Youxi Zhao, Jiajia You, Zhiming Rao","doi":"10.1186/s13068-025-02640-7","DOIUrl":"10.1186/s13068-025-02640-7","url":null,"abstract":"<div><p><span>l</span>-threonine is an integral nutrient for mammals, often used in animal feeds to enhance growth and reduce breeding costs. Developing <span>l</span>-threonine engineered strains that meet industrial production specifications has significant economic value. Here, we developed a biosensor that monitors <span>l</span>-threonine concentration to assist in high-throughput screening to capture high-yielding <span>l</span>-threonine mutants. Among them, the P<sub><i>cysK</i></sub> promoter and CysB protein were used to construct a primary <span>l</span>-threonine biosensor, and then the CysB<sup>T102A</sup> mutant was obtained through directed evolution resulting in a 5.6-fold increase in the fluorescence responsiveness of biosensor over the 0–4 g/L <span>l</span>-threonine concentration range. In addition, the metabolic network of mutant was further optimized through multi-omics analysis and in silico simulation. Ultimately, the THRM13 strain produced 163.2 g/L <span>l</span>-threonine, with a yield of 0.603 g/g glucose in a 5 L bioreactor. The biosensor constructed here could be employed for iterative upgrading of subsequent strains, and these engineering strategies described provide guidance for other chemical overproducers.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02640-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Exploring the synergy between fungal CE15 glucuronoyl esterases and xylanases for lignocellulose saccharification","authors":"Christina Pentari, Constantinos Katsimpouras, Mireille Haon, Jean-Guy Berrin, Anastasia Zerva, Evangelos Topakas","doi":"10.1186/s13068-025-02639-0","DOIUrl":"10.1186/s13068-025-02639-0","url":null,"abstract":"<div><h3>Background</h3><p>Lignin–carbohydrate complexes in lignocellulosic biomass act as a barrier to its biodegradation and biotechnological exploitation. Enzymatic dissociation between lignin and hemicellulose is a key process that allows the efficient bioconversion of both polymers. Glucuronoyl esterases of the Carbohydrate Esterase 15 family target the ester linkages between the glucuronic acid of xylan and lignin moieties, assisting enzymatic biodegradation of lignocellulose.</p><h3>Results</h3><p>In this study, two CE15 glucuronoyl esterases from the white-rot fungi <i>Artolenzites elegans</i> and <i>Trametes ljubarskyi</i> were heterologously expressed in <i>Pichia pastoris</i> and biochemically characterized on the model substrate D-glucuronic acid ester with cinnamyl alcohol and a variety of pretreated lignocellulosic biomasses. The pretreatment method was shown to be a determining factor in revealing both the activity of the esterases on lignocellulose and their synergistic relationships with other hemicellulases. <i>Ae</i>GE15 and <i>Tl</i>GE15 demonstrated activity on pretreated biomass with high hemicellulose and lignin content, increasing saccharification by 57 ± 1 μM and 61 ± 3 μM of xylose equivalents, respectively. Furthermore, the synergy between these CE15 esterases and three xylanases from distinct glycoside hydrolase families (GH10, GH11 and GH30) was investigated on pretreated lignocellulosic samples, highlighting beneficial enzymatic interplays. Pretreated birchwood degradation by <i>An</i>Xyn11 was increased from 6% to approximately 10% by the esterases, based on xylose equivalents of unsubstituted xylooligomers. The GEs also promoted the glucuronoxylanase specificity of <i>Tt</i>Xyn30A, leading up to three-times higher release in aldouronic acids. Finally, a synergistic effect between <i>Ae</i>GE15 and <i>Tm</i>Xyn10 was observed on pretreated corn bran, increasing xylose and xylotriose release by 27 ± 8% and 55 ± 15%, respectively.</p><h3>Conclusions</h3><p>Both CE15 esterases promoted biomass saccharification by the xylanases, while there was a prominent effect on the GH30 glucuronoxylanase regarding the release of aldouronic acids. Overall, this study shed some light on the role of CE15 glucuronoyl esterases in the enzymatic biodegradation of plant biomass, particularly its (arabino)glucuronoxylan component, during cooperative activity with xylanases.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02639-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wangbo Chen, Sun Xu, Shuzhen Zou, Zijian Liu, Yichi Liu, Haozhe Xu, Jiayue Wang, Junjie Ma, Rong Chen, Zhaojiang Zuo
{"title":"Carbohydrate and lipid yield in Microcystis aeruginosa for biofuel production under different light qualities","authors":"Wangbo Chen, Sun Xu, Shuzhen Zou, Zijian Liu, Yichi Liu, Haozhe Xu, Jiayue Wang, Junjie Ma, Rong Chen, Zhaojiang Zuo","doi":"10.1186/s13068-025-02615-8","DOIUrl":"10.1186/s13068-025-02615-8","url":null,"abstract":"<div><h3>Background</h3><p>Biofuels produced from algae have enormous advantages in replacing fossil fuels, and <i>Microcystis aeruginosa</i> has a great potential for biofuel production, due to growing fast to form large amounts of biomass. Light is essential for algal growth, and the optimum light quality can promote the biomass and lipid accumulation for increasing feedstock for biofuel production.</p><h3>Results</h3><p>We investigated the biomass accumulation, photosynthetic ability, carbohydrate, and lipid yield as well as related gene expression in <i>M. aeruginosa</i> under red, blue, purple, and white light to promote biofuel production using this alga under the optimal light quality. Compared with white light, purple light promoted the cell growth during the 5 days, while blue light showed inhibitory effect. Red light had no effect on the cell growth, but improved the biomass content to the highest level. Red light improved the photosynthetic ability by raising chlorophyll level, and up-regulating expression of the genes in chlorophyll biosynthesis, photosynthetic electron transfer, and CO<sub>2</sub> fixation. Among these light qualities, red light showed the maximum effect on soluble, insoluble, and total carbohydrate accumulation by up-regulating the genes in polysaccharide and starch formation, and down-regulating the genes in glycolysis and tricarboxylic acid cycle. Red light also exhibited the maximum effect on lipid accumulation, which might be caused by up-regulating five genes in fatty acid biosynthesis.</p><h3>Conclusion</h3><p>Red light can promote <i>M. aeruginosa</i> accumulating carbohydrates and lipids by regulating related gene expression, which should be the optimal light quality for improving feedstock yield for biofuel production.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02615-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143688472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yashaswini Nagavara Nagaraj, Johanna Blomqvist, Sabine Sampels, Jana Pickova, Mats Sandgren, Peter Gajdoš, Milan Čertík, Volkmar Passoth
{"title":"Supercritical carbon dioxide extraction of lipids and carotenoids from Rhodotorula toruloides CBS 14 in comparison with conventional extraction methods","authors":"Yashaswini Nagavara Nagaraj, Johanna Blomqvist, Sabine Sampels, Jana Pickova, Mats Sandgren, Peter Gajdoš, Milan Čertík, Volkmar Passoth","doi":"10.1186/s13068-025-02632-7","DOIUrl":"10.1186/s13068-025-02632-7","url":null,"abstract":"<div><h3>Background</h3><p>Oil from oleaginous yeasts has the potential to replace non-sustainable vegetable oil as raw material to produce food, feed, biofuels, or biochemicals. Co-produced compounds like carotenoids may be helpful to obtain economically viable bioprocesses. Identifying appropriate extraction methods is a bottleneck both for establishing oleaginous yeasts as cell factories for both oil and carotenoids production and for analysis of intracellular compounds like lipids and carotenoids. We conducted extractions using supercritical carbon dioxide (SC-CO<sub>2</sub>) and conventional solvent methods to extract and analyze lipids and carotenoids from <i>R. toruloides</i> CBS 14 cells grown on wheat straw hydrolysate. The lipid extracts were analyzed using gas chromatography (GC), and the carotenoids were identified and quantified using ultra-high-performance liquid chromatography (UHPLC).</p><h3>Results</h3><p>Four main carotenoids in the extracts from both extraction methods were identified including β-carotene, γ-carotene, torularhodin, and torulene. Interestingly, torularhodin was the major carotenoid extracted using SC-CO<sub>2</sub> extraction, followed by torulene. This was different from the conventional acetone extraction method, where β-carotene was the main carotenoid. After the conventional extraction, torularhodin and torulene underwent degradation due to the saponification step, which was necessary to remove lipids before UHPLC analysis. The total carotenoid concentration obtained from SC-CO<sub>2</sub> extraction was 332.09 ± 27.32 μg/g dry weight compared to 19.9 ± 2.74 μg/g dry weight in acetone extraction. A small amount of carotenoids was observed to be lost into the lipid extract, but this loss was not as substantial as that seen with acetone extraction. Additionally, the total lipid content in samples extracted using SC-CO<sub>2</sub> was significantly lower than that obtained using the conventional Folch method. GC analysis revealed that oleic acid was the major fatty acid in both lipid extracts, followed by palmitic acid and linoleic acid. Notably, the proportion of unsaturated fatty acids was higher in the extracts from the SC-CO<sub>2</sub> method compared to the conventional method.</p><h3>Conclusion</h3><p>These findings indicate that the SC-CO<sub>2</sub> extraction method outperformed conventional methods by preserving the integrity of unsaturated lipids and retaining an abundance of carotenoids, resulting in high-quality extracts.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02632-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143667803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bacillus subtilis surface display technology: applications in bioprocessing and sustainable manufacturing","authors":"Howra Bahrulolum, Gholamreza Ahmadian","doi":"10.1186/s13068-025-02635-4","DOIUrl":"10.1186/s13068-025-02635-4","url":null,"abstract":"<div><p>The growing demand for sustainable and eco-friendly alternatives in bioprocessing, healthcare, and manufacturing has stimulated significant interest in <i>Bacillus subtilis</i> surface display technology. This innovative platform, leveraging both spore and vegetative cell forms, provides exceptional versatility for a wide spectrum of applications, spanning from green technologies to advanced biomedical innovations. The robustness of spores and the metabolic activity of vegetative cells enable efficient enzyme immobilization, biocatalysis, and biosensor development, facilitating bioremediation, pollutant degradation, and renewable energy generation. Additionally, <i>B. subtilis</i> surface display systems have demonstrated remarkable potential in vaccine development and drug delivery, offering a cost-effective, scalable, and environmentally sustainable alternative to traditional methods. These systems can effectively present antigens or therapeutic molecules, enabling targeted drug delivery and robust immune responses. This review explores recent advancements, challenges, and opportunities in harnessing <i>B. subtilis</i> surface display technology for sustainable biomanufacturing, green innovations, and transformative biomedical applications, emphasizing its role in addressing pressing global challenges in environmental sustainability and healthcare.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02635-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flávio Ferreira, Joana Ortigueira, Alberto Reis, Tiago F. Lopes
{"title":"Benchmarking commercially available value-added fractions with potential for production via microalgae-based biorefineries: is it worth it?","authors":"Flávio Ferreira, Joana Ortigueira, Alberto Reis, Tiago F. Lopes","doi":"10.1186/s13068-025-02633-6","DOIUrl":"10.1186/s13068-025-02633-6","url":null,"abstract":"<div><p>The urgent need to mitigate climate change requires finding sustainable and efficient alternatives to fossil fuel-based materials. Biosequestration by microalgae has been suggested as a potential method for climate change mitigation due to its environmentally friendly nature and ability to produce high-value compounds. However, the large-scale application of microalgal biorefineries faces significant challenges, particularly in the harvest and processing stages, which are often costly and energy-intensive. This study aims to benchmark value-added fractions that can be produced via microalgae-based biorefineries against their commercially available counterparts. A systematic review was conducted using the Web of Science™ database to identify current commercial sources of proteins, lipids, polyunsaturated fatty acids and pigments, this study identified key sectors and applications for each fraction, as well as potential market competitors. The results highlight substantial cost differences across production systems, with traditional agricultural sources demonstrating lower CAPEX but greater environmental challenges. Meanwhile, microalgal systems, although associated with higher CAPEX, offer advantages such as reduced land and water dependency, potentially leading to long-term economic resilience and environmental sustainability. By pinpointing research trends, key sectors and optimization opportunities, this work offers valuable insights into the profitability and competitiveness of microalgal systems, providing a benchmark for future optimization efforts. The novelty of this research lies in its comprehensive comparison of microalgae-based and traditional production systems, establishing a clear benchmark for microalgal production and suggesting focus areas for enhancement.</p></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02633-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Isabella Burger, Matthias Schmal, Kathrin Peikert, Lukas Fourtis, Christoph Suster, Christian Stanetty, Dominik Schnalzer, Barbara Hufnagel, Thomas Böttcher, Ruth Birner-Gruenberger, Robert L. Mach, Astrid R. Mach-Aigner, Matthias Schittmayer, Christian Zimmermann
{"title":"Discovery of the antifungal compound ilicicolin K through genetic activation of the ilicicolin biosynthetic pathway in Trichoderma reesei","authors":"Isabella Burger, Matthias Schmal, Kathrin Peikert, Lukas Fourtis, Christoph Suster, Christian Stanetty, Dominik Schnalzer, Barbara Hufnagel, Thomas Böttcher, Ruth Birner-Gruenberger, Robert L. Mach, Astrid R. Mach-Aigner, Matthias Schittmayer, Christian Zimmermann","doi":"10.1186/s13068-025-02628-3","DOIUrl":"10.1186/s13068-025-02628-3","url":null,"abstract":"<div><h3>Background</h3><p>Given the global rise in antimicrobial resistance, the discovery of novel antimicrobial agents and production processes thereof are of utmost importance. To this end we have activated the gene cluster encoding for the biosynthesis of the potent antifungal compound ilicicolin H in the fungus <i>Trichoderma reesei</i>. While the biosynthetic gene cluster (BGC) is silent under standard cultivation conditions, we achieved BGC activation by genetically overexpressing the transcription factor TriliR.</p><h3>Results</h3><p>Successful activation was confirmed by RT-qPCR, proteomic and metabolomic analyses. Metabolomic profiling upon BGC expression revealed high-yield production of ilicicolin H. To elucidate the enzymatically highly diverse functionality of this BGC, we employed a combination of overexpression and deletions of individual genes in the BGC. While we hardly observed any of the previously reported side- or shunt products associated with heterologous ilicicolin H expression, we discovered that <i>Trichoderma reesei</i> produces a novel member of the ilicicolin family using a metabolomic molecular networking approach. This new compound, ilicicolin K, is expressed in substantial amounts in the genetically engineered <i>Trichoderma reesei</i>. Ilicicolin K differs from ilicicolin H in its structure by a second hydroxylation of the tyrosine derived phenol and an additional ring formed by an intramolecular ether bridge of the hydroxyl group at the pyridone towards the tyrosine moiety of the molecule. Bioactivity tests of ilicicolin K revealed a strong antifungal activity against <i>Saccharomyces cerevisiae</i> and a moderate activity against the human pathogen <i>Candida auris</i>, an emerging multi-drug resistant fungus.</p><h3>Conclusions</h3><p>By activating a silent BGC in <i>T. reesei</i>, we obtained a high-yielding strain for the production of the antifungal compounds ilicicolin H and the novel ilicicolin K. These two compounds share some structural properties and are thus highly likely to act on the fungal cytochrome bc1 complex, a component of the mitochondrial repository chain. However, they possess different bioactive properties, which might suggest that ilicicolin K may overcome certain limitations of ilicicolin H.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":494,"journal":{"name":"Biotechnology for Biofuels","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://biotechnologyforbiofuels.biomedcentral.com/counter/pdf/10.1186/s13068-025-02628-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}