International Microbiology最新文献

{"title":"All lactose-oxidizing enzymes of Pseudomonas taetrolens, a highly efficient lactobionic acid-producing microorganism, are pyrroloquinoline quinone-dependent enzymes.","authors":"Seung Soo Lee, Yu-Ri Oh, Young-Ah Jang, So Yeon Han, Gyeong Tae Eom","doi":"10.1007/s10123-023-00477-4","DOIUrl":"10.1007/s10123-023-00477-4","url":null,"abstract":"<p><p>In previous and present studies, four enzymes (GCD1, GCD3, GCD4, and MQO1) have been found to act as lactose-oxidizing enzymes of Pseudomonas taetrolens. To investigate whether the four enzymes were the only lactose-oxidizing enzymes of P. taetrolens, we performed the inactivation of gcd1, gcd3, gcd4, and mqo1 genes in P. taetrolens. Compared to the wild-type strain, the lactobionic acid (LBA)-producing ability of P. taetrolens ∆gcd1 ∆gcd3 ∆gcd4 ∆mqo1 was only slightly decreased, implying that P. taetrolens possesses more lactose-oxidizing enzymes. Interestingly, the four lactose-oxidizing enzymes were all pyrroloquinoline quinone (PQQ)-dependent. To identify other unidentified lactose-oxidizing enzymes of P. taetrolens, we prevented the synthesis of PQQ in P. taetrolens by inactivating the genes related to PQQ synthesis such as pqqC, pqqD, and pqqE. Surprisingly, all three knocked-out strains were unable to convert lactose to LBA, indicating that all lactose-oxidizing enzymes in P. taetrolens were inactivated by eliminating PQQ synthesis. In addition, external PQQ supplementation restored the LBA production ability of P. taetrolens ∆pqqC, comparable to the wild-type strain. These results indicate that all lactose-oxidizing enzymes in P. taetrolens are PQQ-dependent.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139642051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel thiazolinyl-picolinamide-based palladium(II) complex extenuates the virulence and biofilms of vulvovaginal candidiasis (VVC) causing Candida.","authors":"Munieswaran Gayatri, Sowndarya Jothipandiyan, Mohamed Khalid Abdul Azeez, Murugesan Sudharsan, Devarajan Suresh, Paramasivam Nithyanand","doi":"10.1007/s10123-024-00497-8","DOIUrl":"10.1007/s10123-024-00497-8","url":null,"abstract":"<p><p>Candida infections are growing all over the world as a result of their resistance to anti-fungal drugs. This raises concerns about public health, particularly in cases of vulvovaginal candidiasis (VVC). Therefore, the need for effective treatment options for Candida infections has become crucial. The main goal of the study is to evaluate the efficacy of novel palladium metal complexes against fluconazole-resistant Candida spp., particularly C. albicans and C. auris. The process begins with identifying the minimum inhibitory concentration (MIC), followed by growth curve assays, colony morphology analysis, characterization, and gene expression analysis. The investigation revealed that sub-MIC of Pd(II) complex B (250 μg/mL) inhibited Candida spp. more effectively than amphotericin B (500 μg/mL). Further, Pd(II) complex B drastically reduced the growth of Candida spp. biofilms by 70-80% for nascent biofilms and 70-75% for mature biofilms. Additionally, the yeast-to-hyphal switch and SEM studies revealed that Pd(II) complex B effectively hinders the growth of drug-resistant Candida cells. The gene expression investigation also evidenced that Pd(II) complex B downregulated virulence genes in C. albicans (ERG, EFG, UME6, and HGC) and C. auris (ERG, CDR, and HGC). The findings showed that Pd(II) complex B effectively inhibited the growth of Candida biofilm formation and was reported as a potential anti-biofilm agent against Candida spp. that are resistant to drugs.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140101575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced oxidative stress resistance in Ustilago maydis and its implications on the virulence.","authors":"Jorge Cuamatzi-Flores, Maritrini Colón-González, Fernanda Requena-Romo, Samuel Quiñones-Galeana, José Antonio Cervantes-Chávez, Lucia Morales","doi":"10.1007/s10123-024-00489-8","DOIUrl":"10.1007/s10123-024-00489-8","url":null,"abstract":"<p><p>The phytopathogenic fungus Ustilago maydis causes corn smut by suppressing host plant defenses, including the oxidative burst response. While many studies have investigated how U. maydis responds to oxidative stress during infection, the consequences of heightened resistance to oxidative stress on virulence remain understudied. This study aimed to identify the effects on virulence in U. maydis strains exhibiting enhanced resistance to hydrogen peroxide (H₂O₂).To achieve this, we exposed U. maydis SG200 to 20 escalating H₂O₂ shocks, resulting in an adapted strain resistant to concentrations as high as 60 mM of H₂O₂, a lethal dose for the initial strain. Genetic analysis of the adapted strain revealed five nucleotide substitutions, two minor copy number variants, and a large amplification event on chromosome nine (1-149 kb) encompassing the sole catalase gene. Overexpressing catalase increased resistance to H₂O₂; however, this resistance was lower than that observed in the adapted strain. Additionally, virulence was reduced in both strains with enhanced H₂O₂ resistance.In summary, enhanced H₂O₂ resistance, achieved through either continuous exposure to the oxidative agent or through catalase overexpression, decreased virulence. This suggests that the response to the oxidative stress burst in U. maydis is optimal and that increasing the resistance to H₂O₂ does not translate into increased virulence. These findings illuminate the intricate relationship between oxidative stress resistance and virulence in U. maydis, offering insights into its infection mechanisms.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11452521/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139944169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exposure of Cryptococcus neoformans to low nitrogen levels enhances virulence.","authors":"Caylin Bosch, Barbra Toplis, Anton DuPreez Van Staden, Heinrich Volschenk, Carine Smith, Leon Dicks, Alfred Botha","doi":"10.1007/s10123-024-00504-y","DOIUrl":"10.1007/s10123-024-00504-y","url":null,"abstract":"<p><p>Previous studies have shown a correlation between nitrogen levels and Cryptococcus neoformans pathogenicity. Here we report on the in vivo effects of cryptococcal pre-exposure to ecologically relevant nitrogen levels. C. neoformans H99 was cultured in yeast carbon base (YCB) supplemented with 0.53 g/L NH₄Cl and 0.21 g/L NH₄Cl, respectively, and used to infect larvae of the Greater Wax moth, Galleria mellonella. Cells cultured in low nitrogen YCB (LN) were more virulent compared to cells cultured in high nitrogen YCB (HN). Microscopic examination of haemolymph collected from infected larvae revealed that cells cultured in LN were larger than cells cultured in HN, with the majority of LN cells exceeding 10 µm and possibly entering titanisation. Additionally, compared to HN-cultured cells, fewer LN-cultured cells were engulfed by macrophages. The enhanced virulence of LN-cultured cells was attributed to the increased cell size in vivo. In contrast, reduced macrophage uptake was attributed to increased capsule thickness of in vitro cells. Not only do these findings demonstrate the effects of culture conditions, specifically nitrogen levels, on C. neoformans virulence, but they also highlight the importance of isolate background in the cryptococcal-host interaction.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11452460/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140131392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Culturable yeast diversity in urban topsoil influenced by various anthropogenic impacts.","authors":"Anna Glushakova, Aleksandra Tepeeva, Tatiana Prokof'eva, Aleksey Kachalkin","doi":"10.1007/s10123-024-00482-1","DOIUrl":"10.1007/s10123-024-00482-1","url":null,"abstract":"<p><p>In urban ecosystems, processes associated with anthropogenic influences almost always lead to changes in soil micromycete complexes. The taxonomic structure of soil micromycete complexes is an important informative parameter of soil bioindication in the ecological control of urban environments. Unicellular fungi, such as culturable yeasts, are a very suitable and promising object of microbiological research for monitoring urban topsoil. This review aims to give an overview of the yeast communities in urban topsoil in different areas of Moscow (heating main area, household waste storage and disposal area, highway area) and to discuss the changes in the taxonomic structure of culturable yeast complexes depending on the type and intensity of anthropogenic impact.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139542210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of gut microbiome in Pangasionodon hypopthalmus and Labeo catla during health and disease.","authors":"R Bharathi Rathinam, Gayatri Tripathi, Basanta Kumar Das, Ratnesh Jain, Arpit Acharya","doi":"10.1007/s10123-024-00494-x","DOIUrl":"10.1007/s10123-024-00494-x","url":null,"abstract":"<p><p>The present study was conducted to study the composition of gut microbiome in the advanced fingerling and fingerling stage of striped pangasius catfish and catla during healthy and diseased conditions. Healthy pangasius and catla fishes were obtained from commercial farms and injected with the LD₅₀ dose of A. hydrophila. The intestinal samples from the control and injected group were collected and pooled for 16 s metagenomic analysis. Community analysis was performed by targeting the 16 s rRNA gene to explore and compare the gut microbiota composition of these fishes. The operational taxonomic units (OTUs) consisted of four major phyla: Bacteroidia, Proteobacteria, Firmicutes, and Actinobacteria. Alpha and beta diversity indices were carried out to understand the diversity of microbes within and between a sample. While comparing the advanced fingerling and fingerling stage gut microbiome of Pangasius catfish, the dominance of Proteobacteria was found in fingerlings, whereas Firmicutes and Bacteroides were found in advanced fingerlings. In catla, Proteobacteria and Bacteroides were predominant. Taxonomic abundance of the microbiota in control and diseased Pangasius and catla fishes at phylum, class, order, family, genus, and species levels were also depicted. The present study is the first of its kind, and it will help to identify the diversity of novel potential bacterial species involved in disease protection of fishes. It can lead to the development of sustainable prophylactic measures against (re-)emerging bacterial diseases in aquaculture.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140131391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Finding microbial composition and biological processes as predictive signature to access the ongoing status of mangrove preservation.","authors":"Fabíola Marques de Carvalho, Marcele Laux, Luciane Prioli Ciapina, Alexandra Lehmkuhl Gerber, Ana Paula C Guimarães, Vinícius Prata Kloh, Moacir Apolinário, Jorge Eduardo Santos Paes, Célio Roberto Jonck, Ana Tereza R de Vasconcelos","doi":"10.1007/s10123-024-00492-z","DOIUrl":"10.1007/s10123-024-00492-z","url":null,"abstract":"<p><p>Mangroves are complex land-sea transition ecosystems whose microbiota are essential for their nutrient recycling and conservation. Brazil is the third-largest estuarine area in the world and \"Baía de Todos os Santos\" (BTS) is one of the largest bays of the country, with wide anthropogenic exploration. Using a metagenomic approach, we investigated composition and functional adaptability as signatures of the microbiome of pristine and anthropized areas of BTS, including those under petroleum refinery influence. The taxonomic analysis showed dominance of sulfate-reducing Desulfobacteraceae, Rhodobacteraceae, and Flavobacteriaceae. Taxa were significantly diverse between pristine and disturbed areas. Disturbed mangroves showed a notary increase in abundance of halophilic, sulfur-related, and hydrocarbon-degrading genera and a decrease in diatoms compared to pristine area. The metabolic profile of BTS mangroves was correlated with the differentially abundant microbiota. Two ecological scenarios were observed: one marked by functions of central metabolism associated with biomass degradation and another by mechanisms of microbial adaptability to pollution conditions and environmental degradation. Part of the microbiome was distinct and not abundant in Brazilian estuarine soils. The microbiome signature observed in each BTS mangrove reflects how human actions impact the diversity of these ecosystems and also emphasize their role in attempting to restore disturbed mangroves. The microbiome may act as a potential biological indicator of the preservation status of these soils, despite the limitation of soil property conditions. Additionally, our data pointed to metagenomics as an additional tool for environmental assessment and reinforced the need for protective measures for the mangroves under study.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11452435/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139931075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mycorrhizal types determined the response of yield of woody bioenergy crops to environmental factors.","authors":"Mengyuan Luo, Mingli Yuan, Chunhua Ji, Jiakai Gao, Zhaoyong Shi","doi":"10.1007/s10123-024-00601-y","DOIUrl":"https://doi.org/10.1007/s10123-024-00601-y","url":null,"abstract":"<p><p>Meeting the demand for energy solely through fossil fuels has posed challenges. To mitigate the risk of energy shortage, woody bioenergy crops as a renewable energy feedstock have been the subject of many researchers. Also, mycorrhizas play an important role in crop productivity and inevitably affect the biomass yield of woody bioenergy crops. Based on a global synthesis of biomass yield of woody bioenergy crops, a framework for identifying and comparing bioenergy crop biomass in response to mycorrhizal type was developed. Our results found that the biomass yield of woody bioenergy crops in descending order was ectomycorrhizas (ECM) crops (10.2 ton DM ha^-1 year^-1) > arbuscular mycorrhizas (AM)+ECM crops (8.8 ton DM ha^-1 year^-1) > AM crops (8.0 ton DM ha^-1 year^-1). In addition, our analysis revealed that the climate had the strongest effect on biomass yield in AM and ECM crops, whereas geography exerted the most significant influence on biomass yield in AM+ECM crops. Furthermore, there were differences in the biomass yield response of different mycorrhizal and plant types to geographic (latitude and elevation) and climatic factors (mean annual temperature (MAT) and mean annual precipitation (MAP)). When cultivating AM crops, we can focus more on temperature conditions-warmer locations, whereas for ECM crops, selecting regions with higher precipitation levels is advantageous. This study revealed the relationship between mycorrhizae and bioenergy crops. It provides data and theoretical support to rationalize differences in different woody bioenergy crops and their different responses to global change and increased production of bioenergy crops.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142346613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The PulE ATPase is required for twitching motility and DNA donation during Thermus thermophilus transjugation.","authors":"Alba Blesa, Mercedes Sánchez-Costa, José Berenguer","doi":"10.1007/s10123-024-00598-4","DOIUrl":"https://doi.org/10.1007/s10123-024-00598-4","url":null,"abstract":"<p><p>Thermus thermophilus can acquire DNA through natural competence and through transjugation, a mechanism that involves a two-step process of DNA secretion (push) and DNA internalization (pull) between mating cells of related species. The natural competence apparatus (NCA) is required in the recipient mate for the pull step. However, how the DNA exits of the donor cell is only partially known. The putative DNA translocase TdtA, encoded in mobile genetic element ICETh1 of T. thermophilus HB27, was shown to be required for DNA donation as reported by (Blesa et al. 2017a). This ring-shaped hexameric ATPase binds to the membrane and likely interacts with yet unknown secretory components that allow the extrusion of DNA through the membrane; thus, a genetic screening to identify additional putative secretory components was performed. Here, we describe that mutants in gene TT_C1844, which encodes a putative AAA-ATPase named PulE, do not synthesize the recently described \"narrow\" type 4 pili required for twitching motility and made up of the major PilA5 pilin. Concomitantly, pulE mutants also exhibited DNA donation defects during transjugation, suggesting a role of narrow pili in the donation process. However, single pilA5 null mutants still function as DNA donors in transjugation experiments, so we conclude that the need for PulE in transjugation is independent of its role in narrow pili synthesis and twitching motility.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142346614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved levan production by novel Calidifontibacillus erzurumensis LEV207 using one variable at a time approach.","authors":"Palkar Omkar Prakash, Keerthi Rayasam, Vidyullatha Peddireddy, Kolluru Viswanatha Chaitanya","doi":"10.1007/s10123-024-00597-5","DOIUrl":"https://doi.org/10.1007/s10123-024-00597-5","url":null,"abstract":"<p><p>Levan, an exopolysaccharide, has applications in the medical and food sectors. Under natural conditions, levan is produced at a low concentration by microorganisms. This current study focuses on optimizing levan production by a one-variable-at-a-time approach from a novel marine bacterium, Calidifontibacillus erzurumensis LEV207. The growth and levansucrase production by C. erzurumensis LEV207 were studied to optimize the media components and conditions. Sucrose and yeast extract proved to be a good levansucrase inducer. The pH of 6.0 and temperature of 30 °C, along with MgSO₄ as salt, increased the enzyme activity. Sucrose and yeast extract at the concentration of 50% and 1%, respectively, produced the maximum enzyme activity of 427.4 µmol/mL/min after 48 h of incubation. Sevag reagent was used for the purification of levan. The optimization process increased the levan (EPSLEV207) production sevenfold with a final yield of 65.58 g/L. To confirm the structure and nature of EPSLEV207, NMR and XRD were performed, and the functional groups present in EPSLEV207 were determined using FTIR. Chemical hydrolysis of levan confirmed fructose as the monomer, making EPSLEV207 a homopolysaccharide. EPSLEV207 exhibited 49% and 22% radical scavenging activity against DPPH and ABTS radicals, respectively, and promoted the growth of probiotic strain. EPSLEV207 showed an 88% water solubility index and 78% water retention capacity. The optimization process has increased the yield of levan, highlighting the potential of C. erzurumensis LEV207 to be a viable option for industrial applications.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142346603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}