Mevalonolactone (MVAL) is a high-value feedstock for the cosmetic industry, with (R)-(-)-MVAL as the sole bioactive enantiomer. Chemical synthesis, which is the traditional method for MVAL production, is hindered by cumbersome procedures, low chiral purity, and sensitivity to humidity. Microbial fermentation via fermentative mevalonate (MVA) accumulation followed by in vitro acid-catalyzed lactonization has emerged as a promising alternative for producing optically pure (R)-(-)-MVAL. Strategies for MVA overproduction in microbial systems are reviewed, including the selection of chassis strains and enzymes for the MVA biosynthetic pathway, metabolic engineering approaches for strain improvement, optimization of fermentation processes, and downstream processes for MVA-to-MVAL lactonization. Finally, prospects for advancing microbial MVAL production are discussed.
{"title":"Advances in microbial mevalonolactone production: from fermentative mevalonate accumulation to downstream lactonization","authors":"Hao Tang , Lihong Yin , Yiwen Jiang , Teng Xu , Ting Xue , Meimei Fu , Jianghao Chen , Jinshan Guo","doi":"10.1016/j.engmic.2025.100257","DOIUrl":"10.1016/j.engmic.2025.100257","url":null,"abstract":"<div><div>Mevalonolactone (MVAL) is a high-value feedstock for the cosmetic industry, with (<em>R</em>)-(-)-MVAL as the sole bioactive enantiomer. Chemical synthesis, which is the traditional method for MVAL production, is hindered by cumbersome procedures, low chiral purity, and sensitivity to humidity. Microbial fermentation <em>via</em> fermentative mevalonate (MVA) accumulation followed by <em>in vitro</em> acid-catalyzed lactonization has emerged as a promising alternative for producing optically pure (<em>R</em>)-(-)-MVAL. Strategies for MVA overproduction in microbial systems are reviewed, including the selection of chassis strains and enzymes for the MVA biosynthetic pathway, metabolic engineering approaches for strain improvement, optimization of fermentation processes, and downstream processes for MVA-to-MVAL lactonization. Finally, prospects for advancing microbial MVAL production are discussed.</div></div>","PeriodicalId":100478,"journal":{"name":"Engineering Microbiology","volume":"6 1","pages":"Article 100257"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145852437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-02-17DOI: 10.1016/j.engmic.2026.100264
Fei Han , Qian Wang , Yiheng Wang, Xingyu Liu, Yifan Zhang, Kunlong Liang, Xiongfeng Dai, Manlu Zhu
Bacterial growth modulation is crucial in microbial synthetic biology. In this study, we found that glutamate is an extremely poor carbon source for Escherichia coli and Bacillus subtilis. The slow growth on glutamate can be effectively overcome by the heterologous expression of glutamate transporters from Vibrio natriegens. Our results revealed that cross-species substrate transporters could be employed to shift bacterial cellular resource allocation, offering a potential genetic strategy for modulating microbial biomass growth.
{"title":"Heterologous expression of Vibrio natriegens transporters enhances the growth of Escherichia coli and Bacillus subtilis on glutamate","authors":"Fei Han , Qian Wang , Yiheng Wang, Xingyu Liu, Yifan Zhang, Kunlong Liang, Xiongfeng Dai, Manlu Zhu","doi":"10.1016/j.engmic.2026.100264","DOIUrl":"10.1016/j.engmic.2026.100264","url":null,"abstract":"<div><div>Bacterial growth modulation is crucial in microbial synthetic biology. In this study, we found that glutamate is an extremely poor carbon source for <em>Escherichia coli</em> and <em>Bacillus subtilis</em>. The slow growth on glutamate can be effectively overcome by the heterologous expression of glutamate transporters from <em>Vibrio natriegens</em>. Our results revealed that cross-species substrate transporters could be employed to shift bacterial cellular resource allocation, offering a potential genetic strategy for modulating microbial biomass growth.</div></div>","PeriodicalId":100478,"journal":{"name":"Engineering Microbiology","volume":"6 1","pages":"Article 100264"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147397232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-07-03DOI: 10.1016/j.engmic.2025.100223
Xiao-Jie Yuan , Rui Liu , Jian Li , Wen-Xiao Zhao , Hui-Hui Fu , Yan-Rong Zhou , Mei-Ling Sun , Xiu-Lan Chen , Yu-Qiang Zhang
Phytic acid, also known as inositol hexaphosphate (IP6), is one of the most abundant organophosphorus compounds in nature. Its degradation by phytase plays a key role in the natural phosphorus cycle. In addition, phytases are widely used in livestock and poultry feed to enhance phosphorus utilization. While most reported and commercial phytases are derived from terrestrial organisms, relatively few originate from marine microorganisms, and information on the diversity of phytase-producing marine bacteria remains limited. In this study, following enrichment with sodium phytate, we analyzed the bacterial diversity in seawater and sediment samples collected from the coast of Aoshan Bay in Qingdao, China, using 16S rRNA gene amplicon sequencing. A total of 138 OTUs representing 10 phyla, 15 classes, 37 orders, 55 families, and 70 genera were identified. Furthermore, 27 phytase-producing bacterial strains were isolated from the enrichment cultures, primarily belonging to the phyla Firmicutes (14/27) and Proteobacteria (12/27). Five extracellular phytase genes were identified through genome sequencing of three representative strains. These phytases were subsequently expressed and characterized. All were classified as histidine acid phosphatase-type phytases, exhibiting optimal activity at temperatures of 50–60 °C and pH values of 4.0–5.0. Notably, phytase 3919 showed a specific activity as high as 2485.25 U/mg, indicating strong potential for practical applications. This study provides insight into the diversity of coastal bacteria involved in phytic acid degradation, contributing to our understanding of bacterial-driven phosphorus cycling in coastal ecosystems and facilitating the discovery of phytases with industrial potential.
{"title":"Diversity analysis of phytase-producing bacteria from coastal seawater and sediment and characterization of their phytases","authors":"Xiao-Jie Yuan , Rui Liu , Jian Li , Wen-Xiao Zhao , Hui-Hui Fu , Yan-Rong Zhou , Mei-Ling Sun , Xiu-Lan Chen , Yu-Qiang Zhang","doi":"10.1016/j.engmic.2025.100223","DOIUrl":"10.1016/j.engmic.2025.100223","url":null,"abstract":"<div><div>Phytic acid, also known as inositol hexaphosphate (IP6), is one of the most abundant organophosphorus compounds in nature. Its degradation by phytase plays a key role in the natural phosphorus cycle. In addition, phytases are widely used in livestock and poultry feed to enhance phosphorus utilization. While most reported and commercial phytases are derived from terrestrial organisms, relatively few originate from marine microorganisms, and information on the diversity of phytase-producing marine bacteria remains limited. In this study, following enrichment with sodium phytate, we analyzed the bacterial diversity in seawater and sediment samples collected from the coast of Aoshan Bay in Qingdao, China, using 16S rRNA gene amplicon sequencing. A total of 138 OTUs representing 10 phyla, 15 classes, 37 orders, 55 families, and 70 genera were identified. Furthermore, 27 phytase-producing bacterial strains were isolated from the enrichment cultures, primarily belonging to the phyla Firmicutes (14/27) and Proteobacteria (12/27). Five extracellular phytase genes were identified through genome sequencing of three representative strains. These phytases were subsequently expressed and characterized. All were classified as histidine acid phosphatase-type phytases, exhibiting optimal activity at temperatures of 50–60 °C and pH values of 4.0–5.0. Notably, phytase 3919 showed a specific activity as high as 2485.25 U/mg, indicating strong potential for practical applications. This study provides insight into the diversity of coastal bacteria involved in phytic acid degradation, contributing to our understanding of bacterial-driven phosphorus cycling in coastal ecosystems and facilitating the discovery of phytases with industrial potential.</div></div>","PeriodicalId":100478,"journal":{"name":"Engineering Microbiology","volume":"5 4","pages":"Article 100223"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-09-13DOI: 10.1016/j.engmic.2025.100240
Xiaodi Liu , Xiangyu Zhu , Wenxin Jiang , Huanmin Du
Exporter protein systems play a crucial role in the efficient production of valuable chemicals. However, the lack of active exporters significantly limits the application of industrial bio-based production, making the identification and utilization of novel exporters highly important. In this study, we discovered a novel l-Homoserine exporter, Cg0701, in Corynebacterium glutamicum through homology analysis. First, tolerance assays revealed that the cg0701 overexpression strain (CgH-2) exhibited a 10.45% increase in cell growth compared to the control when cultivated with 30 g/L-Homoserine. Additionally, export assays demonstrated that the l-Homoserine export capacity of CgH-2 increased by approximately 30%. Furthermore, genomic overexpression of cg0701 in an l-Homoserine-producing chassis also enhanced both tolerance and export activity. As a result, the recombinant strain CgH-11 produced 10.79 g/L-Homoserine in shake flask cultures and 48.72 g/L in a 5 L fermenter, representing improvements of 19.89% and 24.44%, respectively. In summary, our results indicate that Cg0701 is a novel l-Homoserine exporter in C. glutamicum, enriching our understanding of amino acid export systems and providing a valuable target for the construction of l-Homoserine microbial cell factories.
{"title":"Identification and functional characterization of a potential l-Homoserine exporter in Corynebacterium glutamicum","authors":"Xiaodi Liu , Xiangyu Zhu , Wenxin Jiang , Huanmin Du","doi":"10.1016/j.engmic.2025.100240","DOIUrl":"10.1016/j.engmic.2025.100240","url":null,"abstract":"<div><div>Exporter protein systems play a crucial role in the efficient production of valuable chemicals. However, the lack of active exporters significantly limits the application of industrial bio-based production, making the identification and utilization of novel exporters highly important. In this study, we discovered a novel <span>l</span>-Homoserine exporter, Cg0701, in <em>Corynebacterium glutamicum</em> through homology analysis. First, tolerance assays revealed that the <em>cg0701</em> overexpression strain (CgH-2) exhibited a 10.45% increase in cell growth compared to the control when cultivated with 30 g/L-Homoserine. Additionally, export assays demonstrated that the <span>l</span>-Homoserine export capacity of CgH-2 increased by approximately 30%. Furthermore, genomic overexpression of <em>cg0701</em> in an <span>l</span>-Homoserine-producing chassis also enhanced both tolerance and export activity. As a result, the recombinant strain CgH-11 produced 10.79 g/L-Homoserine in shake flask cultures and 48.72 g/L in a 5 L fermenter, representing improvements of 19.89% and 24.44%, respectively. In summary, our results indicate that Cg0701 is a novel <span>l</span>-Homoserine exporter in <em>C. glutamicum</em>, enriching our understanding of amino acid export systems and providing a valuable target for the construction of <span>l</span>-Homoserine microbial cell factories.</div></div>","PeriodicalId":100478,"journal":{"name":"Engineering Microbiology","volume":"5 4","pages":"Article 100240"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-09-23DOI: 10.1016/j.engmic.2025.100241
Huan Du, Yang Liu
Fighting against antibiotic resistance has an unexpected ally, archaea. Despite the extensive exploration of antimicrobial peptides in bacteria and eukaryotes, the archaeal domain has been overlooked. A recent study employed deep learning to screen archaeasins. The synthesized versions showed a 93 % success rate against pathogens by depolarizing the cytoplasmic membrane, not the outer membrane. This highlights the promise and deep learning power of archaea for antibiotic discovery and the culture of uncultured archaea.
{"title":"Archaeasins as a promising resource for developing next-generation antibiotics uncovered via deep learning","authors":"Huan Du, Yang Liu","doi":"10.1016/j.engmic.2025.100241","DOIUrl":"10.1016/j.engmic.2025.100241","url":null,"abstract":"<div><div>Fighting against antibiotic resistance has an unexpected ally, archaea. Despite the extensive exploration of antimicrobial peptides in bacteria and eukaryotes, the archaeal domain has been overlooked. A recent study employed deep learning to screen archaeasins. The synthesized versions showed a 93 % success rate against pathogens by depolarizing the cytoplasmic membrane, not the outer membrane. This highlights the promise and deep learning power of archaea for antibiotic discovery and the culture of uncultured archaea.</div></div>","PeriodicalId":100478,"journal":{"name":"Engineering Microbiology","volume":"5 4","pages":"Article 100241"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145319913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-06-23DOI: 10.1016/j.engmic.2025.100221
Zihan Huang, Lei Zhang, Ting Cai, Ruijun Liu, Xiaoyan Qi, Xia Wang
Polycyclic aromatic sulfur heterocycles, such as dibenzothiophene (DBT), and their alkylated derivatives are recognized as persistent and toxic contaminants that pose major risks to the environment and human health. Here, a novel electroactive gram-positive bacterium, Lysinibacillus macroides AP, was isolated and identified from a microbial fuel cell (MFC) powered by aromatic compounds. An electricity generation performance with a maximum discharge voltage of 424.59 mV and a power density of 420.95 mW m⁻2 was obtained using L. macroides AP in an MFC fueled with sodium formate. An analysis of the extracellular electron transfer (EET) mechanism indicated that the endogenous redox mediators produced by L. macroides AP were not detected, but exogenous redox mediators such as thionine acetate and anthraquinone-2, 6-disulfonate could temporarily enhance EET. The characterization of biofilm morphology revealed a dense network of microbial nanowires on the cell surface of L. macroides AP; the abundance of these nanowires was positively correlated with the discharge efficiency of the MFC, suggesting that the nanowires generated by L. macroides AP cells were likely to promote EET. Additionally, effective bioelectricity generation and simultaneous DBT degradation were successfully achieved using L. macroides AP in MFCs, with a power density of 385.20 mW m⁻2 and 88.72 % DBT removal. This is the first report on a novel ecological role of L. macroides AP as a gram-positive electroactive bacterium, emphasizing its potential applications in environmental remediation and energy recovery.
多环芳香族硫杂环，如二苯并噻吩（DBT）及其烷基化衍生物被认为是对环境和人类健康构成重大风险的持久性有毒污染物。本文从芳香族化合物驱动的微生物燃料电池（MFC）中分离并鉴定了一种新的电活性革兰氏阳性细菌——大内溶杆菌（Lysinibacillus macroides）。在以甲酸钠为燃料的MFC中，大环内酯酸钠的最大放电电压为424.59 mV，功率密度为420.95 mW m - 2。胞外电子转移（EET）机制分析表明，未检测到大环内酯AP产生的内源性氧化还原介质，但外源性氧化还原介质如乙酸硫氨酸和蒽醌- 2,6 -二磺酸盐可以暂时增强EET。生物膜形态表征表明，大圆叶藻细胞表面存在密集的微生物纳米线网络；这些纳米线的丰度与MFC的放电效率呈正相关，表明L. macroides AP细胞产生的纳米线可能促进EET。此外，使用L. macroides AP在mfc中成功地实现了有效的生物发电和同时降解DBT，功率密度为385.20 mW m - 2， DBT去除率为88.72%。本文首次报道了大胞内酯杆菌作为革兰氏阳性电活性细菌的新生态作用，强调了其在环境修复和能量回收方面的潜在应用。
{"title":"Electricity generation and dibenzothiophene biodegradation using a novel electroactive bacterium Lysinibacillus macroides AP in microbial fuel cells","authors":"Zihan Huang, Lei Zhang, Ting Cai, Ruijun Liu, Xiaoyan Qi, Xia Wang","doi":"10.1016/j.engmic.2025.100221","DOIUrl":"10.1016/j.engmic.2025.100221","url":null,"abstract":"<div><div>Polycyclic aromatic sulfur heterocycles, such as dibenzothiophene (DBT), and their alkylated derivatives are recognized as persistent and toxic contaminants that pose major risks to the environment and human health. Here, a novel electroactive gram-positive bacterium, <em>Lysinibacillus macroides</em> AP, was isolated and identified from a microbial fuel cell (MFC) powered by aromatic compounds. An electricity generation performance with a maximum discharge voltage of 424.59 mV and a power density of 420.95 mW m⁻<sup>2</sup> was obtained using <em>L. macroides</em> AP in an MFC fueled with sodium formate. An analysis of the extracellular electron transfer (EET) mechanism indicated that the endogenous redox mediators produced by <em>L. macroides</em> AP were not detected, but exogenous redox mediators such as thionine acetate and anthraquinone-2, 6-disulfonate could temporarily enhance EET. The characterization of biofilm morphology revealed a dense network of microbial nanowires on the cell surface of <em>L. macroides</em> AP; the abundance of these nanowires was positively correlated with the discharge efficiency of the MFC, suggesting that the nanowires generated by <em>L. macroides</em> AP cells were likely to promote EET. Additionally, effective bioelectricity generation and simultaneous DBT degradation were successfully achieved using <em>L. macroides</em> AP in MFCs, with a power density of 385.20 mW m⁻<sup>2</sup> and 88.72 % DBT removal. This is the first report on a novel ecological role of <em>L. macroides</em> AP as a gram-positive electroactive bacterium, emphasizing its potential applications in environmental remediation and energy recovery.</div></div>","PeriodicalId":100478,"journal":{"name":"Engineering Microbiology","volume":"5 4","pages":"Article 100221"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144572628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-07-30DOI: 10.1016/j.engmic.2025.100228
Yao-Kun Zhang , Liang Zhang , Xue Ni , Shu-Wen Zhang , Min-Zhi Jiang , Si-Lu Zhang , Guo-Xun Xiao , He Jiang , Ming-Xia Bi , Yu-Lin Wang , Chang Liu , Shuang-Jiang Liu
Bifidobacterium animalis subsp. lactis is a well-known probiotic with potential benefits for alleviating sub-health symptoms, including immune dysfunction and anxiety. Given the strain-specific nature of its probiotic effects, identifying effective strains for sub-health alleviation is crucial. In this study, we characterized 16 B animalis subsp. lactis isolates from fecal samples and probiotic sources. We assessed the genotype-phenotype correlations related to growth, carbon source utilization, and stress tolerance in vitro. Subsequently, we profiled 107 metabolites (including 28 alcohols and 17 esters) and quantified the levels of short-chain fatty acids and three other organic acids. Three B. animalis strains, GOLDGUT-BB21, WLBA7, and WLBA6, were selected and evaluated in a sleep-deprived mouse model. In vivo, WLBA3 reduced inflammation and oxidative stress by inhibiting the NLRP3 inflammasome pathway and modulating gut microbiota (e.g., Lactobacillus and Alistipes), which in turn significantly improved weight gain and fatigue resistance, attenuated cognitive function, and anxiety-like behavior. These findings provide insights into the diversity of B. animalis subsp. lactis strain resources and highlight the potential of WLBA3 as a candidate for alleviating sub-health symptoms.
{"title":"Bifidobacterium animalis subsp. lactis genome resources and metabolite profiling at the strain level and their ability to alleviate anxiety-like behavior in a sleep-deprived mouse model","authors":"Yao-Kun Zhang , Liang Zhang , Xue Ni , Shu-Wen Zhang , Min-Zhi Jiang , Si-Lu Zhang , Guo-Xun Xiao , He Jiang , Ming-Xia Bi , Yu-Lin Wang , Chang Liu , Shuang-Jiang Liu","doi":"10.1016/j.engmic.2025.100228","DOIUrl":"10.1016/j.engmic.2025.100228","url":null,"abstract":"<div><div><em>Bifidobacterium animalis</em> subsp. <em>lactis</em> is a well-known probiotic with potential benefits for alleviating sub-health symptoms, including immune dysfunction and anxiety. Given the strain-specific nature of its probiotic effects, identifying effective strains for sub-health alleviation is crucial. In this study, we characterized 16 <em>B animalis</em> subsp. <em>lactis</em> isolates from fecal samples and probiotic sources. We assessed the genotype-phenotype correlations related to growth, carbon source utilization, and stress tolerance <em>in vitro</em>. Subsequently, we profiled 107 metabolites (including 28 alcohols and 17 esters) and quantified the levels of short-chain fatty acids and three other organic acids. Three <em>B. animalis</em> strains, GOLDGUT-BB21, WLBA7, and WLBA6, were selected and evaluated in a sleep-deprived mouse model. <em>In vivo</em>, WLBA3 reduced inflammation and oxidative stress by inhibiting the NLRP3 inflammasome pathway and modulating gut microbiota (e.g., <em>Lactobacillus</em> and <em>Alistipes</em>), which in turn significantly improved weight gain and fatigue resistance, attenuated cognitive function, and anxiety-like behavior. These findings provide insights into the diversity of <em>B. animalis</em> subsp. <em>lactis</em> strain resources and highlight the potential of WLBA3 as a candidate for alleviating sub-health symptoms.</div></div>","PeriodicalId":100478,"journal":{"name":"Engineering Microbiology","volume":"5 4","pages":"Article 100228"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144866543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-09-23DOI: 10.1016/j.engmic.2025.100243
Zhiqi Hu , Mengyuan Su , Qibing Liu , Ying Li , Yunxiang Liang , Shuangquan Li , Yingjun Li
Glutathione (GSH), an essential tripeptide thiol critical for cellular redox regulation, has significant value in the pharmaceutical and nutraceutical industries. To overcome limitations of traditional GSH extraction methods, this study established a microbial cell factory platform in Saccharomyces cerevisiae through integrated metabolic engineering strategies: (1) host strain screening identified NJ-SQYY with superior GSH accumulation (74.14 mg·L⁻¹, 8.27 mg·g-1 dry cell weight [DCW]); (2) CRISPR/Cas9-mediated genomic integration of bacterial gshAB introduced with a bifunctional glutathione synthetase; (3) systematic optimization via promoter tuning and Gsh1-Gsh2 enzyme fusion, and CYS3 overexpression-resolved γ-glutamylcysteine bottlenecks. These interventions synergistically enhanced GSH synthesis to 339.3 mg·L⁻¹ in shake flasks (4.6-fold increase), representing the highest reported titer in chromosomally engineered S. cerevisiae. Scaling to dissolved oxygen-coupled fed-batch fermentation in a 5-L bioreactor produced 997.46 mg·L⁻¹ GSH at 33.85 mg·g⁻¹ DCW. This study demonstrated a holistic metabolic engineering-to-bioprocessing approach for industrial GSH biomanufacturing.
{"title":"Systems metabolic engineering of glutathione biosynthesis in Saccharomyces cerevisiae: Pathway balancing coupled with enzyme screening for high-titer production","authors":"Zhiqi Hu , Mengyuan Su , Qibing Liu , Ying Li , Yunxiang Liang , Shuangquan Li , Yingjun Li","doi":"10.1016/j.engmic.2025.100243","DOIUrl":"10.1016/j.engmic.2025.100243","url":null,"abstract":"<div><div>Glutathione (GSH), an essential tripeptide thiol critical for cellular redox regulation, has significant value in the pharmaceutical and nutraceutical industries. To overcome limitations of traditional GSH extraction methods, this study established a microbial cell factory platform in <em>Saccharomyces cerevisiae</em> through integrated metabolic engineering strategies: (1) host strain screening identified NJ-SQYY with superior GSH accumulation (74.14 mg·L⁻¹, 8.27 mg·g<sup>-1</sup> dry cell weight [DCW]); (2) CRISPR/Cas9-mediated genomic integration of bacterial <em>gshAB</em> introduced with a bifunctional glutathione synthetase; (3) systematic optimization via promoter tuning and Gsh1-Gsh2 enzyme fusion, and <em>CYS3</em> overexpression-resolved γ-glutamylcysteine bottlenecks. These interventions synergistically enhanced GSH synthesis to 339.3 mg·L⁻¹ in shake flasks (4.6-fold increase), representing the highest reported titer in chromosomally engineered <em>S. cerevisiae</em>. Scaling to dissolved oxygen-coupled fed-batch fermentation in a 5-L bioreactor produced 997.46 mg·L⁻¹ GSH at 33.85 mg·g⁻¹ DCW. This study demonstrated a holistic metabolic engineering-to-bioprocessing approach for industrial GSH biomanufacturing.</div></div>","PeriodicalId":100478,"journal":{"name":"Engineering Microbiology","volume":"5 4","pages":"Article 100243"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145319912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-08-06DOI: 10.1016/j.engmic.2025.100229
Carlos Cartin-Caballero , Christophe Collet , Daniel Gapes , Peter A. Gostomski , Matthew B. Stott , Carlo R. Carere
The verrucomicrobial methanotroph, Methylacidiphilum sp. RTK17.1, and the microalgae, Galdieria sp. RTK37.1 are both thermoacidophilic microorganisms isolated from geothermally heated soils at Rotokawa, Aotearoa-New Zealand. In this work, we used cocultures of Methylacidiphilum sp. RTK17.1 and Galdieria sp. RTK37.1 in batch and continuous systems (45 °C, pH 2.5) to assess their biomass productivity and performance; with the goal of removing methane and carbon dioxide from simulated waste gas streams and assessing the resultant biomass for its potential use as single cell protein. Coculture performance was compared to corresponding axenic cultures and the nutritional suitability of resultant biomass was assessed as a single cell protein feedstock. Stable coculture was achieved in both batch and chemostat systems. In batch experiments, Galdieria sp. RTK37.1 significantly enhanced growth (29 %) and methane oxidation (300 %) rates of Methylacidiphilum sp. RTK17.1, and complete methane removal was achieved without formation of an explosive gas mixture. In steady state chemostat coculture experiments, Galdieria sp. RTK37.1 decreased net volumetric oxygen consumption by 46 %, but its oxygenic activity was unable to supply Methylacidiphilum sp. RTK17.1 with the O2 required for complete CH4 removal. Nevertheless, Methylacidiphilum sp. RTK17.1 benefited from the presence of Galdieria sp. RTK37.1 in a low O2 environment; with O2 algae-methanotroph cross-feeding playing a fundamental role on their interactions. Methylacidiphilum sp. RTK17.1, Galdieria sp. RTK37.1, and their coculture each displayed similar nutritional profiles, with protein quality comparable to soybean meal and fishmeal feeds used for animals. The biomass needed to meet the daily indispensable amino acid requirements of a 62 kg adult human was 568 g for Methylacidiphilum sp. RTK17.1, 804 g Galdieria sp. RTK37.1, and 754 g for the coculture, with histidine being the limiting amino acid. These thermoacidophilic cocultures, which have not previously been investigated, offer great potential to convert low (or negative) value industrial gas streams into valuable products (e.g. supplementary biofeedstocks).
{"title":"Simultaneous co-cultivation of the thermoacidophilic methanotroph, Methylacidiphilum sp. RTK17.1, and the microalga, Galdieria sp. RTK37.1, for single cell protein production","authors":"Carlos Cartin-Caballero , Christophe Collet , Daniel Gapes , Peter A. Gostomski , Matthew B. Stott , Carlo R. Carere","doi":"10.1016/j.engmic.2025.100229","DOIUrl":"10.1016/j.engmic.2025.100229","url":null,"abstract":"<div><div>The verrucomicrobial methanotroph, <em>Methylacidiphilum</em> sp. RTK17.1, and the microalgae, <em>Galdieria</em> sp. RTK37.1 are both thermoacidophilic microorganisms isolated from geothermally heated soils at Rotokawa, Aotearoa-New Zealand. In this work, we used cocultures of <em>Methylacidiphilum</em> sp. RTK17.1 and <em>Galdieria</em> sp. RTK37.1 in batch and continuous systems (45 °C, pH 2.5) to assess their biomass productivity and performance; with the goal of removing methane and carbon dioxide from simulated waste gas streams and assessing the resultant biomass for its potential use as single cell protein. Coculture performance was compared to corresponding axenic cultures and the nutritional suitability of resultant biomass was assessed as a single cell protein feedstock. Stable coculture was achieved in both batch and chemostat systems. In batch experiments, <em>Galdieria</em> sp. RTK37.1 significantly enhanced growth (29 %) and methane oxidation (300 %) rates of <em>Methylacidiphilum</em> sp. RTK17.1, and complete methane removal was achieved without formation of an explosive gas mixture. In steady state chemostat coculture experiments, <em>Galdieria</em> sp. RTK37.1 decreased net volumetric oxygen consumption by 46 %, but its oxygenic activity was unable to supply <em>Methylacidiphilum</em> sp. RTK17.1 with the O<sub>2</sub> required for complete CH<sub>4</sub> removal. Nevertheless, <em>Methylacidiphilum</em> sp. RTK17.1 benefited from the presence of <em>Galdieria</em> sp. RTK37.1 in a low O<sub>2</sub> environment; with O<sub>2</sub> algae-methanotroph cross-feeding playing a fundamental role on their interactions. <em>Methylacidiphilum</em> sp. RTK17.1, <em>Galdieria</em> sp. RTK37.1, and their coculture each displayed similar nutritional profiles, with protein quality comparable to soybean meal and fishmeal feeds used for animals. The biomass needed to meet the daily indispensable amino acid requirements of a 62 kg adult human was 568 g for <em>Methylacidiphilum</em> sp. RTK17.1, 804 g <em>Galdieria</em> sp. RTK37.1, and 754 g for the coculture, with histidine being the limiting amino acid. These thermoacidophilic cocultures, which have not previously been investigated, offer great potential to convert low (or negative) value industrial gas streams into valuable products (e.g. supplementary biofeedstocks).</div></div>","PeriodicalId":100478,"journal":{"name":"Engineering Microbiology","volume":"5 4","pages":"Article 100229"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-08-19DOI: 10.1016/j.engmic.2025.100232
Yingbo Yuan , Tianyuan Su , Yi Zheng, Baoyue Liu, Yuanfei Han, Zhongcan Wang, Quanfeng Liang, Longyang Dian, Qingsheng Qi
Polystyrene (PS) is a polyolefin plastic that is used extensively in food packaging. The chemical structure of PS is extremely stable owing to its C-C backbone and styrene rings, making it highly resistant to biodegradation, which causes serious environmental pollution and health threats. Although certain microorganisms have been reported to degrade PS waste, most studies have focused on the changes in the molecular weight and surface structure of plastics. These slight degradation phenomena make it extremely difficult to detect the degradation products, thus challenging the definitive demonstration of PS degradation. This study investigated the co-cultivation of the polyolefin plastic-degrading bacterium Raoultella sp. DY2415 and the benzoic acid bioconversion strain Pseudomonas putida KT2440-ΔRBC. BA is a possible degradation product of PS and can be converted by P. putida KT2440-ΔRBC into the high value-added compound muconic acid (MA). After co-cultivation, MA was detected in the medium, indicating that Raoultella sp. DY2415 degraded PS and generated BA, which was subsequently utilized by P. putida KT2440-ΔRBC for MA synthesis. This study demonstrated the biodegradation of PS and the synthesis of MA through a fully biological process, thereby promoting the circular economy of plastics.
{"title":"Bacterial co-cultivation for the degradation of polystyrene plastics","authors":"Yingbo Yuan , Tianyuan Su , Yi Zheng, Baoyue Liu, Yuanfei Han, Zhongcan Wang, Quanfeng Liang, Longyang Dian, Qingsheng Qi","doi":"10.1016/j.engmic.2025.100232","DOIUrl":"10.1016/j.engmic.2025.100232","url":null,"abstract":"<div><div>Polystyrene (PS) is a polyolefin plastic that is used extensively in food packaging. The chemical structure of PS is extremely stable owing to its C-C backbone and styrene rings, making it highly resistant to biodegradation, which causes serious environmental pollution and health threats. Although certain microorganisms have been reported to degrade PS waste, most studies have focused on the changes in the molecular weight and surface structure of plastics. These slight degradation phenomena make it extremely difficult to detect the degradation products, thus challenging the definitive demonstration of PS degradation. This study investigated the co-cultivation of the polyolefin plastic-degrading bacterium <em>Raoultella</em> sp. DY2415 and the benzoic acid bioconversion strain <em>Pseudomonas putida</em> KT2440-ΔRBC. BA is a possible degradation product of PS and can be converted by <em>P. putida</em> KT2440-ΔRBC into the high value-added compound muconic acid (MA). After co-cultivation, MA was detected in the medium, indicating that <em>Raoultella</em> sp. DY2415 degraded PS and generated BA, which was subsequently utilized by <em>P. putida</em> KT2440-ΔRBC for MA synthesis. This study demonstrated the biodegradation of PS and the synthesis of MA through a fully biological process, thereby promoting the circular economy of plastics.</div></div>","PeriodicalId":100478,"journal":{"name":"Engineering Microbiology","volume":"5 4","pages":"Article 100232"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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