Fems Microbiology Letters最新文献

{"title":"Eco-Friendly Synthesis of Silver Nanoparticles using Lignin Peroxidase Produced from Caldibacillus thermoamylovorans and Cultivated on Waste Walnut Shell.","authors":"Sefa Nur Akkaya, Ammar Almansour, Mehmet Akif Omeroglu, Hayrunnisa Nadaroglu, Ahmet Adiguzel","doi":"10.1093/femsle/fnaf036","DOIUrl":"https://doi.org/10.1093/femsle/fnaf036","url":null,"abstract":"<p><p>The preparation of silver nanoparticles (AgNPs) via an environmentally friendly green synthesis method represents an ecologically promising alternative. This research aims to develop sustainable and eco-friendly AgNPs using the lignin peroxidase (LiP) enzyme from Caldibacillus thermoamylovorans, cultivated on waste walnut shells, which are rich in lignin, to meet the growing demand for AgNPs. Among thermophilic bacteria that were isolated, the Caldibacillus thermoamylovorans SA1 strain showed the highest LiP activity. The production of LiP was optimized by adding waste walnut shells and manipulating the environmental parameters. The optimal conditions were determined at 50 g/L shell amount, 96 h, pH 8, 140 rpm, and 60°C. In parallel with the increase in enzyme activity, bacterial growth also increased. As a result of the optimization, the highest enzyme activity value was 435.0 U/mL and bacterial growth was determined to be OD600: 2.09. The extracellular medium obtained from the bacteria grown in walnut shell medium was then added to an AgNO3 solution. Efficient production of AgNPs was achieved by stirring the mixture at 50-60°C for 4 h under optimum conditions. The synthesized AgNPs were characterized using a range of analytical techniques, including UV‒Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The biological efficacy of the synthesized AgNPs was evaluated by assessing their antibacterial activity against pathogenic bacteria, such as Escherichia coli O157:H7, Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus pyogenes, and Bacillus cereus. The highest activity was observed against B. cereus (15 mm). The broad-spectrum antibacterial properties exhibited by the AgNPs synthesized in this study offer a promising and sustainable solution for diverse applications in various sectors, including the environmental, agricultural, medical, and pharmaceutical fields.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143709140","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":"Antibiofilm activity of Clitoria ternatea flowers anthocyanin fraction against biofilm-forming oral bacteria.","authors":"Allimalar Sathiaseelan, Keang Peng Song, Hock Siew Tan, Wee Sim Choo","doi":"10.1093/femsle/fnaf035","DOIUrl":"https://doi.org/10.1093/femsle/fnaf035","url":null,"abstract":"<p><p>This study investigated the antibiofilm effects of Clitoria ternatea flowers anthocyanin fraction (AF) on Streptococcus mutans, Actinomyces viscosus and Aggregatibacter actinomycetemcomitans. AF was obtained using column chromatography, and liquid chromatography-mass spectrometry was employed for its characterization and identification. The crystal violet assay and scanning electron microscopy analysis revealed significant inhibition of early biofilm formation and destruction of preformed biofilms after AF treatment (0.94-15 mg mL-1). Anti-adhesion assay on acrylic teeth demonstrated that AF effectively hampered sucrose dependent and independent attachment. Importantly, growth curve and pH drop assays showed that AF inhibited pH reduction for all bacteria tested without hindering bacterial growth. Furthermore, the tetrazolium-based cytotoxicity assay indicated no toxicity towards normal human gingival fibroblasts (HGF-1) at 0.78-12.5 mg mL-1. These findings suggest C. ternatea anthocyanins are promising antibiofilm agents for oral biofilm control, acting during both initial formation and on mature biofilms.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143699540","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":"Survival of Salmonella during dry salting process of pork feet.","authors":"Rafaela Busnello, Luisa Aneiros Gené, Mariane Ferreira Silva, Fabiola Cacciatore, Nathanyelle Soraya Martins de Aquino, Eduardo Tondo","doi":"10.1093/femsle/fnaf034","DOIUrl":"https://doi.org/10.1093/femsle/fnaf034","url":null,"abstract":"<p><p>Pork feet (PF) contaminated with Salmonella are often discarded by the food industry, because heat treatment is not economically viable for these products. Dry salting can be an alternative to heat treatment if it can significantly reduce Salmonella populations. The aim of this study was to assess the Salmonella´s survival in PF during dry salting process. Firstly, Salmonella was quantified in contaminated PF coming from the food industry. Thereafter, PF samples were artificially contaminated with three levels of Salmonella (3, 6 and 8 log CFU/g) and stored at 10°C for 30 days. Salmonella survival was assessed by counts on Xylose Lysine Deoxycholate Agar, Mannitol Lysine Crystal-Violet Brilliant-Green Agar and by the 3M™ 2 Molecular Detection Assay (MDA). After 18 days of salting, the 3 log CFU/g inoculum was no longer detected by the cultural and detection methods. The 6 and 8 log CFU/g inoculums were not detected on the agar plates after 26 days of salting but were still positive by MDA. Considering that Salmonella counts in contaminated PF in the food industry was 1.56 log CFU/g and that populations of 3 to 8 log CFU/g of Salmonella were reduced to unculturable levels after dry salting, this process could contribute to the control of Salmonella in PF.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143669577","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":"Priestia and Phytobacter sp. prevent membrane damage and electrolyte leakage from Capsicum annuum L. seeds subjected to sub-optimal temperature stress.","authors":"Prima Bagui, Poulomi Pal, Nipa Biswas, Bratati Chowdhury, Binayak Chakraborty, Prithwiraj Dey, Kapudeep Karmakar","doi":"10.1093/femsle/fnaf033","DOIUrl":"https://doi.org/10.1093/femsle/fnaf033","url":null,"abstract":"<p><p>Unlike the Himalayas, the sub-Himalayan zones didn't experience snowfall and thus suitable for growing solanaceous vegetables. However, several cold waves have been reported to affect the district of Coochbehar (West Bengal, India), which belongs to the Cwa zone (as per Koppen's classification). Variable duration of sub-optimal soil temperature can have a detrimental effect on the growth of seedlings. Our previous study demonstrates that a constant temperature of 20 °C (6 degrees below the optimal soil temperature) causes a 71% loss of vigor in seeds of solanaceous plants. Since the soil temperature is not constant diurnally, it was hypothesized that the duration of cold stress can have variable effects on vigor of Capsicum annuum L. It was observed that increasing the duration of cold stress (18 °C) up to 2 hours/day can improve the vigor but after 6 hours/day, a significant drop in vigor was observed. This was because of the cold-associated membrane damage leading to the leakage of electrolytes. To date, this stress existing in these regions has gone unnoticed. In this regard, biopriming the seeds with exopolysaccharide-producing microbes can be useful as the exopolysaccharide (EPS) can form a protective layer on the seeds. Two lesser-known bacteria namely, Phytobacter and Priestia sp. were evaluated for their vigor-recovering ability. Treatment of seed with these microbes reduced the electrolyte leakage which improved the vigor under sub-optimal stress. This was also validated by fluorescent microscopy. Both these strains displayed an enhanced EPS-producing ability at 18 °C which correlated with the reduced electrolyte leakage and enhanced stability of cell membrane. Such bacteria can help in promoting seed vigor under sub-optimal temperature stress.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143656389","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":"Biofilm destruction activity of α-tocopherol against Staphylococcus aureus, Proteus mirabilis and Pseudomonas aeruginosa.","authors":"Pui Yee Leong, Wei Qi Tan, Wee Sim Choo","doi":"10.1093/femsle/fnaf020","DOIUrl":"https://doi.org/10.1093/femsle/fnaf020","url":null,"abstract":"<p><p>Antibiotic resistance and the persistence of sessile cells within biofilms complicate the eradication of biofilm-related infections using conventional antibiotics. This highlights the necessity for alternate therapy methods. The objective of this study was to investigate the biofilm destruction activity of α-tocopherol against Staphylococcus aureus, Proteus mirabilis and Pseudomonas aeruginosa on polystyrene. α-Tocopherol showed significant biofilm destruction activity on the pre-formed biofilms of S. aureus (45-46%), Pr. mirabilis (42-54%) and Ps. aeruginosa (28%). Resazurin assay showed that α-tocopherol disrupted all bacteria biofilms without interfering with their cell viability. Scanning electron microscope images showed lower bacterial cell count and less compacted cell aggregates on polystyrene surfaces after treatment with alpha-tocopherol. This study demonstrated the biofilm destruction activity of alpha-tocopherol against S. aureus, Pr. mirabilis and Ps. aeruginosa. α-Tocopherol could potentially be used to decrease biofilm-associated infections of these bacteria.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143188809","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":"Metataxonomic analysis of halophilic archaea community in two geothermal oases in the southern Tunisian Sahara.","authors":"Afef Najjari, Khaled Elmnasri, Hanene Cherif, Stephen Burleigh, Amel Guesmi, Mouna Mahjoubi, Javier A Linares-Pastén, Ameur Cherif, Hadda-Imene Ouzari","doi":"10.1093/femsle/fnae106","DOIUrl":"10.1093/femsle/fnae106","url":null,"abstract":"<p><p>This study assesses halophilic archaea's phylogenetic diversity in southern Tunisia's geothermal water. In the arid southern regions, limited surface freshwater resources make geothermal waters a vital source for oases and greenhouse irrigation. Three samples, including water, sediment, and halite soil crust, were collected downstream of two geothermal springs of the Ksar Ghilane (KGH) and Zaouet Al Aness (ZAN) oases, Tunisia. The samples were subjected to 16S rRNA gene sequencing using the Illumina Miseq sequencing approach. Several haloarchaea were identified in the geothermal springs. The average taxonomic composition revealed that 20 out of 33 genera were shared between the two geothermal sources, with uneven distribution, where the Halogranum genus was the most represented genus with an abundance of 18.9% and 11.58% for ZAW and KGH, respectively. Several unique site-specific genera were observed: Halonotius, Halopelagius, Natronorubrum, and Haloarcula in ZAN, and Haloprofundus, Halomarina, Halovivax, Haloplanus, Natrinema, Halobium, Natronoarchaeum, and Haloterrigena in the KGH pool. Most genus members are typically found in low-salinity ecosystems. These findings suggest that haloarchaea can disperse downstream from geothermal sources and may survive temperature and chemical fluctuations in the runoff.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11719619/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142827961","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":"Aeration promotes Proteobacteria over Firmicutes in macerated food waste, resulting in superior anaerobic digestion efficiency.","authors":"Linjie Tang, Mike Manefield","doi":"10.1093/femsle/fnaf001","DOIUrl":"10.1093/femsle/fnaf001","url":null,"abstract":"<p><p>Aeration is a common pretreatment method to enhance biogas production via anaerobic digestion of waste organic feedstocks such as unused food. While impacts on downstream anaerobic digestion have been intensively investigated, the consequence of aeration on the microbial community in food waste has not been characterized. Food waste has a low pH resulting from the dominance of lactic acid bacteria within the Firmicutes phylum. This excludes other phylotypes with a higher potential to hydrolyse complex biopolymers in food waste. In this study, we reveal that aeration of macerated food waste results in a dramatic shift away from Firmicutes towards dominance of Proteobacteria that are better known for extracellular enzyme production. Given that hydrolysis is the rate limiting step in anaerobic digestion, this explains why aeration improves the efficiency of biogas production from food waste. The discovery that Proteobacteria dominate microbial communities in aerated food waste opens up opportunities to manipulate extracellular enzyme production through gene expression mechanisms common among Proteobacteria such as quorum sensing.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142964311","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":"In vitro evolution of ciprofloxacin resistance in Neisseria commensals and derived mutation population dynamics in natural Neisseria populations.","authors":"Leah R Robinson, Caroline J McDevitt, Molly R Regan, Sophie L Quail, Crista B Wadsworth","doi":"10.1093/femsle/fnae107","DOIUrl":"10.1093/femsle/fnae107","url":null,"abstract":"<p><p>Commensal Neisseria are members of a healthy human oropharyngeal microbiome; however, they also serve as a reservoir of antimicrobial resistance for their pathogenic relatives. Despite their known importance as sources of novel genetic variation for pathogens, we still do not understand the full suite of resistance mutations commensal species can harbor. Here, we use in vitro selection to assess the mutations that emerge in response to ciprofloxacin selection in commensal Neisseria by passaging four replicates of four different species in the presence of a selective antibiotic gradient for 20 days; then categorized derived mutations with whole genome sequencing. Ten out of sixteen selected cells lines across the four species evolved ciprofloxacin resistance (≥1 ug/ml); with resistance-contributing mutations primarily emerging in DNA gyrase subunit A and B (gyrA and gyrB), topoisomerase IV subunits C and E (parC and parE), and the multiple transferable efflux pump repressor (mtrR). Of note, these derived mutations appeared in the same loci responsible for ciprofloxacin-reduced susceptibility in the pathogenic Neisseria, suggesting conserved mechanisms of resistance across the genus. Additionally, we tested for zoliflodacin cross-resistance in evolved strain lines and found 6 lineages with elevated zoliflodacin minimum inhibitory concentrations. Finally, to interrogate the likelihood of experimentally derived mutations emerging and contributing to resistance in natural Neisseria, we used a population-based approach and identified GyrA 91I as a substitution circulating within commensal Neisseria populations and ParC 85C in a single gonococcal isolate. A small cluster of gonococcal isolates shared commensal alleles at parE, suggesting recent cross-species recombination events.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11774118/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142946898","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":"Exploring 1-alkene biosynthesis in bacterial antagonists and Jeotgalicoccus sp. ATCC 8456.","authors":"Matthias Schweitzer, Andrea Marianne Friedrich, Alexander Dennig, Gabriele Berg, Christina Andrea Müller Bogotá","doi":"10.1093/femsle/fnaf004","DOIUrl":"10.1093/femsle/fnaf004","url":null,"abstract":"<p><p>Terminal olefins are important platform chemicals, drop-in compatible hydrocarbons and also play an important role as biocontrol agents of plant pathogens. Currently, 1-alkenes are derived from petroleum, although microbial biosynthetic routes are known. Jeotgalicoccus sp. ATCC 8456 produces 1-alkenes via the fatty acid decarboxylase OleTJE. UndA and UndB are recently identified non-heme iron oxidases converting medium-chain fatty acids into terminal alkenes. Our knowledge about the diversity and natural function of OleTJE, UndA, and UndB homologs is scarce. We applied a combined screening strategy-solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME GC-MS) and polymerase chain reaction (PCR)-based amplification-to survey an environmental strain collection for microbial 1-alkene producers and their corresponding enzymes. Our results reinforce the high level of conservation of UndA and UndB genes across the genus Pseudomonas. In vivo production of defined 1-alkenes (C9-C13; C15; C19) was directed by targeted feeding of fatty acids. Lauric acid feeding enabled 1-undecene production to a concentration of 3.05 mg l-1 in Jeotgalicoccus sp. ATCC 8456 and enhanced its production by 105% in Pseudomonas putida 1T1 (1.10 mg l-1). Besides, whole genome sequencing of Jeotgalicoccus sp. ATCC 8456 enabled reconstruction of the 1-alkene biosynthetic pathway. These results advance our understanding of microbial 1-alkene synthesis and the underlying genetic basis.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11776017/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142978102","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":"Properties of the Ureaplasma parvum structural maintenance of chromosomes protein related to its interaction with DNA.","authors":"Natalia A Rumyantseva, Vladimir M Shutov, Dina G Belenkaia, Aleksandr A Alekseev, Natalia E Morozova, Alexey D Vedyaykin","doi":"10.1093/femsle/fnaf010","DOIUrl":"10.1093/femsle/fnaf010","url":null,"abstract":"<p><p>SMC (Structural Maintenance of Chromosomes) ATPase proteins are integral components of complexes bearing the same name, crucial for the spatial organization of DNA across diverse life forms, spanning bacteria, archaea, and eukaryotes. It is proposed that in bacteria, SMC complexes facilitate DNA compaction through loop extrusion and aid in the segregation of daughter nucleoids. In this paper, the properties of the SMC ATPase protein from Ureaplasma parvum were investigated by using a spectrum of methods, including conventional biochemical methods as well as advanced single-molecule techniques. Our findings reveal distinctive properties of this protein compared to its extensively studied homologue from Bacillus subtilis. Notably, our results suggest that U. parvum Smc ATPase facilitates DNA compaction even in the absence of ATP.</p>","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143074380","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}