Microbiological research最新文献

{"title":"Sphingomonas arvum sp. nov.: A promising microbial chassis for high-yield and sustainable zeaxanthin biomanufacturing","authors":"Chun-Zhi Jin ,&nbsp;So Young Park ,&nbsp;Chang-Jin Kim ,&nbsp;Kee-Sun Shin ,&nbsp;Jong-Min Lee","doi":"10.1016/j.micres.2024.127938","DOIUrl":"10.1016/j.micres.2024.127938","url":null,"abstract":"<div><div>The yield of natural products from plants is currently insufficient and cannot be considered a sustainable and secure source of supply, especially given the challenges posed by global climate change. Therefore, a biofoundry that can quickly and accurately produce desired materials from microorganisms based on synthetic biology is urgently needed. Moreover, it is important to find new microbial and genetic chassis to meet the rapidly growing global market for high-value-added zeaxanthin. In this study, we aimed to identify the zeaxanthin biosynthetic gene cluster, <em>crtZ</em>-<em>crtB</em>-<em>crtI</em>-<em>crtY</em>, and confirm zeaxanthin production (11,330 μg g⁻¹ dry biomass weight) through genome mining and liquid chromatography/mass spectrometry profiling using the novel zeaxanthin-producing bacteria <em>Sphingomonas</em> sp. strain BN140010^T isolated from the subsurface soil of arable land. We report the highest yield among zeaxanthin-producing <em>Sphingomonas</em> strains to date. Moreover, we determined the taxonomic position of BN140010^T using a polyphasic approach based on phylogenetic, physiological and chemotaxonomic characteristics, and we proposed <em>Sphingomonas arvum</em> strain BN140010^T as a novel strain. Our results provide a zeaxanthin-producing chassis and diverse genetic tools for microbiological zeaxanthin production. Therefore, this research advances our progress towards the goal of lowering the unit cost of zeaxanthin production, making it more accessible for industrial applications.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"290 ","pages":"Article 127938"},"PeriodicalIF":6.1,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Colanic acid and lipopolysaccharide in Pectobacterium carotovorum Pcc21 serve as receptors for the bacteriophage phiPccP-2","authors":"Nguyen Trung Vu ,&nbsp;Hyeongsoon Kim ,&nbsp;In Sun Hwang ,&nbsp;Chang-Sik Oh","doi":"10.1016/j.micres.2024.127939","DOIUrl":"10.1016/j.micres.2024.127939","url":null,"abstract":"<div><div>Bacteriophages (phages) are viruses that specifically bind to and infect target bacteria. The phage phiPccP-2, belonging to the <em>Myoviridae</em> family, efficiently controls <em>Pectobacterium</em> spp. In the present study, we aimed to elucidate the mechanism of recognition of <em>P. carotovorum</em> Pcc21 by phiPccP-2. The EZ-Tn5 transposon mutant library of Pcc21 was used to screen for phage-resistant mutants. Among 4072 mutants screened, 12 harbored disruptions in genes associated with the biosynthesis of either colanic acid (CA) or lipopolysaccharide (LPS) showed resistance to phiPccP-2. Complementation of 4 representative phage-resistant mutants with the corresponding genes fully restored the binding ability and lytic activity of PhiPccP-2. The amounts of CA or LPS structure in these mutants were significantly altered compared with those in the wild-type strain. Adsorption competition assays between CA and LPS extracted from Pcc21 and the natural receptors in Pcc21 showed that unbound phages were significantly increased, indicating that both CA and LPS are associated with the adsorption of the phiPccP-2 to Pcc21. In contrast, the adsorption of phiPccP-2 to extracted CA or LPS did not inactivate the lytic activity of phiPccP-2, indicating that the adsorption to the extracted CA or LPS is not sufficient for DNA injection. Treatment with polymyxin B, which disrupts LPS, interfered with phiPccP-2 adsorption to Pcc21. Furthermore, phage-resistant mutants showed reduced virulence in the host plant, suggesting a trade-off between phage resistance and bacterial virulence. Overall, our results indicate that both CA and LPS serve as receptors for the binding of phiPccP-2 to <em>P. carotovorum</em> Pcc21.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"290 ","pages":"Article 127939"},"PeriodicalIF":6.1,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulation of Bacillus Calmette-Guérin-induced macrophage autophagy and apoptosis by the AMPK–mTOR–ULK1 pathway","authors":"Ruiqian Li ,&nbsp;Tianle He ,&nbsp;Min Yang ,&nbsp;Jinghua Xu ,&nbsp;Yongqin Li ,&nbsp;Xueyan Wang ,&nbsp;Xuelian Guo ,&nbsp;Mingzhu Li ,&nbsp;Lihua Xu","doi":"10.1016/j.micres.2024.127952","DOIUrl":"10.1016/j.micres.2024.127952","url":null,"abstract":"<div><div>Tuberculosis (TB) is a chronic wasting infectious disease caused by <em>Mycobacterium tuberculosis</em> (MTB) or <em>Mycobacterium bovis</em> that can be transmitted among people and domestic animals. During the development of TB, macrophages of the innate immune system can act against MTB via autophagy and apoptosis to prevent the spread of the disease. Among the many autophagy regulatory pathways, the adenosine monophosphate (AMP)–activated protein kinase (AMPK)–mammalian rapamycin target protein (mTOR)–Unc-51-like kinase 1 (ULK1) pathway has received considerable attention. This study investigates the regulatory role of the AMPK–mTOR–ULK1 pathway in attenuating <em>M. bovis</em> Bacillus Calmette–Guérin (BCG)-induced autophagy and apoptosis in murine monocyte macrophages (RAW264.7). Changes in macrophage autophagy and apoptosis were analyzed using the AMPK activator AICAR and inhibitor Compound C to interfere with the AMPK–mTOR–ULK1 pathway and siRNA to silence the pathway. Consequently, BCG stimulation of macrophages significantly activated the AMPK–mTOR–ULK1 pathway while BCG-induced macrophage AMPK activation promoted macrophage autophagy and apoptosis. Activation of the AMPK–mTOR–ULK1 pathway by AICAR significantly improved autophagy occurrence in BCG-induced macrophages and increased apoptosis while Compound C with siRNA produced opposing effects by attenuating autophagy and apoptosis in BCG-induced macrophages. Thus, the AMPK–mTOR–ULK1 pathway has a dual regulatory role in BCG-induced macrophage autophagy and apoptosis and may have synergistic effects. This study analyzes the mechanism of resistance of host cells to MTB and provides a theoretical basis for new therapeutic strategies and related drug development.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"290 ","pages":"Article 127952"},"PeriodicalIF":6.1,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use in a controlled environment of Trichoderma asperellum ICC012 and Trichoderma gamsii ICC080 to manage FHB on common wheat","authors":"Marco Cesarini ,&nbsp;Arianna Petrucci ,&nbsp;Eliverta Hotaj ,&nbsp;Giovanni Venturini ,&nbsp;Riccardo Liguori ,&nbsp;Sabrina Sarrocco","doi":"10.1016/j.micres.2024.127941","DOIUrl":"10.1016/j.micres.2024.127941","url":null,"abstract":"<div><div>Fusarium head blight (FHB) represents a significant threat for wheat production due to the risk for food security and safety. Despite the huge number of biofungicides on the market, only one is actually available at European level to control Fusarium infections on cereals. The present work aimed to assess the possible use of <em>Trichoderma asperellum</em> strain ICC012 and <em>Trichoderma gamsii</em> strain ICC080 to manage FHB on common wheat <em>Triticum aestivum</em> cv Apogee. Initially, the capability of ICC012 and ICC080 to endophytically colonize wheat roots, a prerequisite very often correlated with the induction of resistance in the host plant, was investigated. It resulted in 100 % of roots internally colonized by the two strains, followed by a significant up-regulation of the defense-related genes encoding for pathogenesis-related protein 1 (<em>pr1</em>)<em>,</em> superoxide dismutase (<em>sod</em>), polygalacturonase inhibitor protein 2 (<em>pgip2</em>) and phenylalanine ammonia-lyase 1 <em>(pal1</em>). When the expression of the same genes was investigated in spikes treated at the flowering stage with the two strains, applied individually or co-inoculated, a significant up-regulation of only <em>pal1</em> was registered 24 hours post inoculation (hpi) in spikes treated with ICC080. To check if a systemic defense response was induced, the expression of the same genes was analyzed in leaves collected 7 and 14 days post inoculation (dpi) of roots, resulting in a significant up-regulation of <em>sod</em> at 7 dpi in leaves collected from plants inoculated with ICC012. Even if induction of resistance is probably not the main mode of action of the two strains, ICC012 and ICC080 applied on spikes at anthesis significantly reduced, in greenhouse conditions, the Disease Incidence (DI) caused by the inoculation mix of <em>F. graminearum</em>, <em>F. culmorum</em>, <em>F. langsethiae</em> and <em>F. sporotrichioides</em>, four of the most important FHB casual agents. This reduction in disease symptoms was observed when the two beneficial strains were applied both individually and co-inoculated on the spikes. Finally, ICC012 and ICC080 demonstrated a good competitive ability for substrate possession. The amount of <em>F. graminearum</em> (as DNA and number of perithecia) on wheat straw pieces was significantly reduced after 6 months of incubation in presence of the two beneficial strains, applied individually and co-inoculated. Being cultural debris used to overwinter, this competitive behavior of ICC012 and ICC080 is an important trait to reduce the potential inoculum of the pathogen. The results collected here lay the groundwork for the use of ICC012 and ICC080 in managing FHB on common wheat<strong>.</strong></div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"290 ","pages":"Article 127941"},"PeriodicalIF":6.1,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pseudomonas produce various metabolites displaying herbicide activity against broomrape","authors":"Tristan Lurthy ,&nbsp;Florence Gerin,&nbsp;Marjolaine Rey ,&nbsp;Pierre-Edouard Mercier ,&nbsp;Gilles Comte ,&nbsp;Florence Wisniewski-Dyé ,&nbsp;Claire Prigent-Combaret","doi":"10.1016/j.micres.2024.127933","DOIUrl":"10.1016/j.micres.2024.127933","url":null,"abstract":"<div><div>Pseudomonads are well-known for their plant growth-promoting properties and biocontrol capabilities against microbial pathogens. Recently, their potential to protect crops from parasitic plants has garnered attention. This study investigates the potential of different <em>Pseudomonas</em> strains to inhibit broomrape growth and to protect host plants against weed infestation. Four <em>Pseudomonas</em> strains, two <em>P. fluorescens</em> JV391D17 and JV391D10, one <em>P. chlororaphis</em> JV395B and one <em>P. ogarae</em> F113 were cultivated using various carbon sources, including fructose, pyruvate, fumarate, and malate, to enhance the diversity of potential Orobanche growth inhibition (OGI)-specialized metabolites produced by <em>Pseudomonas</em> strains. Both global and targeted metabolomic approaches were utilized to identify specific OGI metabolites. Both carbon sources and <em>Pseudomonas</em> genetic diversity significantly influenced the production of OGI metabolites. <em>P. chlororaphis</em> JV395B and <em>P. ogarae</em> F113 produced unique OGI metabolites belonging to different chemical families, such as hydroxyphenazines and phloroglucinol compounds, respectively. Additionally, metabolomic analyses identified an unannotated potential OGI ion, M375T65. This ion was produced by all <em>Pseudomonas</em> strains but was found to be over-accumulated in JV395B, which likely explains its superior OGI activity. Then, greenhouse experiments were performed to evaluate the biocontrol efficacy of selected strains: they showed the efficacy of these strains, particularly JV395B, in reducing broomrape infestation in rapeseed. These findings suggest that certain <em>Pseudomonas</em> strains, through their metabolite production, can offer a sustainable biocontrol strategy against parasitic plants. This biocontrol activity can be optimized by environmental factors, such as carbon amendments. Ultimately, this approach presents a promising alternative to chemical herbicides.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"290 ","pages":"Article 127933"},"PeriodicalIF":6.1,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial chemotaxis in degradation of xenobiotics: Current trends and opportunities","authors":"Zhipeng Zhuang ,&nbsp;Sivasamy Sethupathy ,&nbsp;Yadira Bajón-Fernández ,&nbsp;Shehbaz Ali ,&nbsp;Lili Niu ,&nbsp;Daochen Zhu","doi":"10.1016/j.micres.2024.127935","DOIUrl":"10.1016/j.micres.2024.127935","url":null,"abstract":"<div><div>Chemotaxis, the directed movement of microbes in response to chemical gradients, plays a crucial role in the biodegradation of xenobiotics, such as pesticides, industrial chemicals, and pharmaceuticals, which pose significant environmental and health risks. Emerging trends in genomics, proteomics, and synthetic biology have advanced our understanding and control of these processes, thereby enabling the development of engineered microorganisms with tailored chemotactic responses and degradation capabilities. This process plays an essential physiological role in processes, such as surface sensing, biofilm formation, quorum detection, pathogenicity, colonization, symbiotic interactions with the host system, and plant growth promotion. Field applications have demonstrated the potential of bioremediation for cleaning contaminated environments. Therefore, it helps to increase the bioavailability of pollutants and enables bacteria to access distantly located pollutants. Despite considerable breakthroughs in decoding the regulatory mechanisms of bacterial chemotaxis, there are still gaps in knowledge that need to be resolved to harness its potential for sensing and degrading pollutants in the environment. This review covers the role of bacterial chemotaxis in the degradation of xenobiotics present in the environment, focusing on chemotaxis-based bacterial and microfluidic biosensors for environmental monitoring. Finally, we highlight the current challenges and future perspectives for developing more effective and sustainable strategies to mitigate the environmental impact of xenobiotics.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"290 ","pages":"Article 127935"},"PeriodicalIF":6.1,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Warm growing season activates microbial nutrient cycling to promote fertilizer nitrogen uptake by maize","authors":"Chao He ,&nbsp;Jean Damascene Harindintwali ,&nbsp;Hao Cui ,&nbsp;Jia Yao ,&nbsp;Zhirong Wang ,&nbsp;Qingyang Zhu ,&nbsp;Fang Wang ,&nbsp;Jingping Yang","doi":"10.1016/j.micres.2024.127936","DOIUrl":"10.1016/j.micres.2024.127936","url":null,"abstract":"<div><div>The influence of nitrogen (N) inputs on soil microbial communities and N uptake by plants is well-documented. Seasonal variations further impact these microbial communities and their nutrient-cycling functions, particularly within multiple cropping systems. Nevertheless, the combined effects of N fertilization and growing seasons on soil microbial communities and plant N uptake remain ambiguous, thereby constraining our comprehension of the optimal growing season for maximizing crop production. In this study, we employed ¹⁵N isotope labeling, high-throughput sequencing, and quantitative polymerase chain reaction (qPCR) techniques to investigate the effects of two distinct growing seasons on microbial communities and maize ¹⁵N uptake ratios (¹⁵NUR). Our results showed that the warm growing season (26.6 °C) increased microbial diversity, reduced network complexity but enhanced stability, decreased microbial associations, and increased modularization compared to the cool growing season (23.1 °C). Additionally, the warm growing season favored oligotrophic species and increased the abundance of microbial guilds and functional genes related to N, phosphorus, and sulfur cycling. Furthermore, alterations in the characteristics of soil microbial keystone taxa were closely linked to variations in maize ¹⁵NUR. Overall, our findings demonstrate significant seasonal variations in soil microbial diversity and functioning, with maize exhibiting higher ¹⁵NUR during the warm growing season of the double cropping system.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"290 ","pages":"Article 127936"},"PeriodicalIF":6.1,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Depth-dependent effects of forest diversification on soil functionality and microbial community characteristics in subtropical forests","authors":"Kai Ding ,&nbsp;Meng Lu ,&nbsp;Yuting Zhang ,&nbsp;Qiyan Liu ,&nbsp;Yiman Zhang ,&nbsp;Yinrong Li ,&nbsp;Qi Yang ,&nbsp;Zhenming Shen ,&nbsp;Zaikang Tong ,&nbsp;Junhong Zhang","doi":"10.1016/j.micres.2024.127931","DOIUrl":"10.1016/j.micres.2024.127931","url":null,"abstract":"<div><div>Soil microbes are critical to the maintenance of forest ecosystem function and stability. Forest diversification, such as monocultures versus mixed forests stands, can strongly influence microbial community patterns and processes, as well as their role in soil ecosystem multifunctionality, such as in subtropical forest ecosystems. However, less is known about these patterns and processes vary with soil depth. Here, we investigated the results of an eight-year forest diversification field experiment comparing the soil ecosystem multifunctionality, bacterial and fungal community assembly, and network patterns in mixed versus monoculture plantations along vertical profiles (0–80 cm depth) in a subtropical region. We found that the introduction of broadleaf trees in coniferous monocultures led to enhanced synergies between multiple functions, thus improving soil multifunctionality. The effects of mixed plantations on the functional potential in top soils were greater than in deep soils, especially for carbon degradation genes (<em>apu</em>, <em>xylA</em>, <em>cex</em>, and <em>glx</em>). Microbial community assembly in the top layer, particularly in mixed plantations, was dominated by stochastic processes, whereas deterministic were more important in the deep layer. Soil microbial network complexity and stability were higher in the top layer of mixed plantations, but in the deep layer was monoculture. Interestingly, the changes in microbial communities and multifunctionality in the top layer were mainly related to variation in nutrients, whereas those in the deep were more influenced by soil moisture. Overall, we reveal positive effects of mixed forest stands on soil microbial characteristics and functionality compared to that of monocultures. Our findings highlighted the importance of enhancing functional diversity through the promotion of tree species diversity, and managers can better develop forest management strategies to promote soil health under global change scenarios.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"289 ","pages":"Article 127931"},"PeriodicalIF":6.1,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142503924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fungal degradation of phenylacetate focusing on CRISPR/Cas9-assisted characterization of two oxidative enzyme genes of Akanthomyces muscarius AM1091","authors":"Sinil Kim ,&nbsp;Yeon-Jae Choi ,&nbsp;Hyerang Eom ,&nbsp;Hyeon-Su Ro","doi":"10.1016/j.micres.2024.127934","DOIUrl":"10.1016/j.micres.2024.127934","url":null,"abstract":"<div><div>The degradation of phenylacetate (PA) was investigated as a model to explore aromatic compound breakdown in the fungal system. Fungal strains capable of utilizing PA as their sole carbon source were isolated using a minimal solid medium supplemented with 0.5 % PA. Subsequent cultivation in minimum liquid medium revealed that selected fungal strains, including <em>Trametes versicolor</em> TV0876 and TV3295, <em>Paecilomyces hepiali</em> PH4477, and <em>Akanthomyces muscarius</em> AM1091, efficiently removed PA within 24 h. HPLC analysis of culture supernatants from various fungal strains revealed a time-dependent accumulation of 2-hydroxyphenylacetate (2-HPA) and 4-hydroxyphenylacetate (4-HPA), two key major metabolic products primarily found in ascomycetes and basidiomycetes, respectively. This suggests that the first hydroxylation of PA is catalyzed by two distinct hydroxylases, one for each fungal group. Furthermore, fungal species that make 4-HPA also produce phenylethanol (PE), indicating a distinct catabolic mechanism to remove PA by direct reduction of PA to PE. <em>A. muscarius</em> AM1091, identified as the most efficient PA degrader in this study, was studied further to determine the biochemical pathway of PA degradation. RNA-Seq and RT-PCR analyses of AM1091 revealed two oxidative enzyme genes, <em>CYP1</em> and <em>DIO4,</em> upregulated in the presence of PA. Targeted disruption utilizing preassembled Cas9-gRNA ribonucleoprotein complexes and homologous DNAs harboring the <em>URA3</em> gene as an auxotrophic marker resulted in the <em>cyp1</em> and <em>dio4</em> mutant strains. The <em>cyp1</em> mutant was incapable of converting PA to 2-HPA, indicating its involvement in the C2 hydroxylation, whereas the <em>dio4</em> mutant was unable to degrade 2,5-dihydroxyphenylacetate (2,5-DHPA), resulting in the accumulation of 2,5-DHPA. Our findings indicate that <em>A. muscarius</em> AM1091 degrades PA through the activities of CYP1 and DIO4 for the C2 hydroxylation and subsequent ring-opening reactions, respectively.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"289 ","pages":"Article 127934"},"PeriodicalIF":6.1,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142503926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of leucine on mitochondria and oxidative stress to reduce virulence and pathogenicity of Acinetobacter baumannii","authors":"Jianxia Zhou ,&nbsp;Dingyun Feng ,&nbsp;Yuetao Chen ,&nbsp;Xia Li ,&nbsp;Jiemei Cen ,&nbsp;Wenbin Wu ,&nbsp;Wenzheng Zheng ,&nbsp;Wenlei Gan ,&nbsp;Tiantuo Zhang","doi":"10.1016/j.micres.2024.127932","DOIUrl":"10.1016/j.micres.2024.127932","url":null,"abstract":"<div><div>Elucidating the virulence mechanisms of <em>A. baumannii</em> is essential for developing strategies to mitigate pathogenicity. Although high-virulent strains are associated with increased mortality rate in severely infected patients, the underlying mechanisms remains not well understood. Our analysis revealed leucine as a pivotal biomarker, with the <em>11d</em>P and <em>paa</em>K being significant contributors to virulence. The ATP-dependent activity and antioxidant activity were identified as the most important pathways in distinguishing the virulence of <em>A. baumannii</em>. Exogenous leucine was found to modulate mitochondria dysfunction and oxidative stress, thereby diminishing the pathogenicity of <em>A. baumannii</em> towards Beas 2B cells. Moreover, leucine reduced the virulence of <em>A. baumannii</em> to <em>Galleria mellonella</em> (<em>G. mellonella</em>) and alleviated pathological damage to lung tissues in mice. Our study offers a novel treatment strategy based on metabolomics, which may assist in the exploration and management of infections caused by highly virulent pathogens. It sets a new course for reducing the impact of highly virulent <em>A. baumannii</em> infections and has significant implications for the development of future therapeutic interventions.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"290 ","pages":"Article 127932"},"PeriodicalIF":6.1,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142503927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}