Current Microbiology最新文献

{"title":"Community Assembly Mechanisms of nirK- and nirS-type Denitrifying Bacteria in Sediments of Eutrophic Lake Taihu, China.","authors":"Mamun Abdullah Al, Dandan Zhang, Sirui Liu, Yuzhen Ming, Mingyue Li, Peng Xing, Xiaoli Yu, Mingyang Niu, Kun Wu, Wei Xie, Zhili He, Qingyun Yan","doi":"10.1007/s00284-024-04032-w","DOIUrl":"10.1007/s00284-024-04032-w","url":null,"abstract":"<p><p>Denitrifying bacteria, particularly nirK- and nirS-type, are functionally equivalent and could occupy different niches, but their community assembly mechanisms and responses to environmental heterogeneity are poorly understood in eutrophic lakes. In this study, we investigated the community assembly mechanisms of nirK- and nirS-type denitrifying bacteria and clarified their responses to sediments environmental factors in Lake Taihu, China. The quantitative real-time PCR and Illumina HiSeq-based sequencing revealed that the abundance and composition of two types of denitrifying bacterial communities varied among different sites in the sediments of Lake Taihu. The functions of these two types of denitrifying bacteria were assigned to mainly nitrogen cycling along with carbon, oxygen, and sulfur cycling, indicating their diverse ecosystems functions. Neutral community model showed that majority of nirK- and nirS-type denitrifying bacteria were neutrally distributed, while dispersal and selection were the dominant drivers in shaping community assembly of nirK-type bacteria. The community assembly of nirS-type was mainly driven by homogeneous selection. We found complex network interactions between nirK- and nirS-type denitrifying bacteria with other bacterial communities, indicating the importance of other bacterial coexistence for ecosystem functions by denitrifying bacteria in lake sediments. Keystone taxa of other bacteria showed the highest interactions with denitrifying bacteria; further, a strong significant correlation between keystone taxa with environmental factors and sediment enzyme content revealed by Mantel tests. Specially, total phosphorous was the key environmental factor determining the composition and diversity of nirK and nirS-type denitrifying bacteria in lake sediments, whereas NAR, AmoA, and NIR were the key reductase enzymes directly or indirectly affected to them. Our results provide significant insights into understanding the effects of changing nirK- and nirS-type denitrifying bacterial diversities and underlying community assembly mechanisms under changing environmental conditions in eutrophic lake ecosystems.</p>","PeriodicalId":11360,"journal":{"name":"Current Microbiology","volume":"82 1","pages":"53"},"PeriodicalIF":2.3,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142876630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the Prebiotic Potential of Fermented Astragalus Polysaccharides on Gut Microbiota Regulation In Vitro.","authors":"Pengshuo Yang, Qing Zhou, Yingying Zhang, Mingyue Jia, Runshuang Li, Qingsong Qu, Zhixun Li, Minfang Feng, Yuting Tian, Weishuo Ren, Xinhui Peng, Xinyuan Shi","doi":"10.1007/s00284-024-04035-7","DOIUrl":"10.1007/s00284-024-04035-7","url":null,"abstract":"<p><p>Astragalus polysaccharides (APS) are known for their prebiotic properties, and fermentation by probiotics is a promising strategy to enhance the prebiotic activity of polysaccharides. In this study, Lactobacillus rhamnosus was used to ferment APS, and response surface methodology was applied to optimize the fermentation parameters. The optimal conditions were determined as follows: 10.28% APS addition, 5.83% inoculum, 35.6 h of fermentation time, and a temperature of 34.6 °C. Additionally, the effects of Fermented Astragalus polysaccharides (FAPS) on human gut microbiota were investigated through in vitro anaerobic incubation. Fecal samples were obtained from 6 healthy volunteers, which were then individually incubated with FAPS. Results demonstrated that FAPS significantly regulated microbial composition and diversity, increasing the abundance of beneficial gut bacteria such as Lactobacillus, E. faecalis, and Brautobacterium, while inhibiting harmful species such as Shigella, Romboutsia, and Clostridium_sensu_stricto_1. Furthermore, FAPS enhanced the production of short-chain fatty acids (SCFAs), which are increasingly recognized to play a role in intestinal homeostasis. These findings suggested that FAPS offers several advantages in terms of increasing beneficial metabolites and regulating gut microbial composition. This study provides valuable insights for expanding the use of plant-derived polysaccharides in the food industry and for developing functional dietary supplements.</p>","PeriodicalId":11360,"journal":{"name":"Current Microbiology","volume":"82 1","pages":"52"},"PeriodicalIF":2.3,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142871739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Description of Massilia orientalis sp. nov., Isolated from Rhizosphere Soil of Ageratina adenophora.","authors":"Yun Xia, Xing-Feng Qian, Xin Chen, Bo Wang, Yong-Xia Wang","doi":"10.1007/s00284-024-04008-w","DOIUrl":"10.1007/s00284-024-04008-w","url":null,"abstract":"<p><p>A novel bacteria strain, designated YIM B02787^T, was isolated from rhizosphere soil of Ageratina adenophora, in Yunnan, southwest China. The strain was aerobic, Gram-stain-negative, rod-shaped and motile with one polar flagellum. Growth occurred at 4-45 °C (optimum, 20-30 °C) and pH 6.0-10.0 (optimum, 7.0-8.0), and in presence of 0-1% (w/v) NaCl. Phylogenetic analyses based on both 16S rRNA gene and genome sequences data revealed that strain YIM B02787^T belongs to the genus Massilia, being closely related to Massilia phosphatilytica KCTC 52513^T (98.93% similarity), M. putida KCTC 42761^T (98.86%), and M. kyonggiensis JCM 19189^T (98.78%). The DNA G+C content was 65.9%. The digital DNA-DNA hybridization and average nucleotide identity values between the isolate strain and aforementioned closely neighbors were low, at 35.8-48.9 and 88.5-92.5%, respectively. Strain YIM B02787^T contained Q-8 as the ubiquinone and major fatty acids were summed feature 3 (C_16:1ω7c and/or C_16:1ω6c, 45.5%) and C_16:0 (27.5%). The polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, two unidentified phospholipids, two unidentified aminophospholipids, and one unidentified polar lipid. On the basis of its phylogenetic, phenotypic and chemotaxonomic characteristics, strain YIM B02787^Trepresents a novel species of the genus Massilia, for which the name Massilia orientalis sp. nov. is proposed. The type strain is YIM B02787^T (= NBRC 116628^T = CGMCC 1.61539^T).</p>","PeriodicalId":11360,"journal":{"name":"Current Microbiology","volume":"82 1","pages":"51"},"PeriodicalIF":2.3,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142871738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photosynthetic Toxicological Effects of Organic Extracts from Zanthoxylum bungeanum Leaves on Controlling the Microcystis aeruginosa Blooms.","authors":"Jie Cheng, Long Tan, Xue Lu, Mengyu Zheng, Chengshuai Xu, Wei Xu, Tong Jiang, Chaobo Zhang","doi":"10.1007/s00284-024-04026-8","DOIUrl":"10.1007/s00284-024-04026-8","url":null,"abstract":"<p><p>In recent years, the frequent occurrence of algal blooms has posed continuous threats to aquatic ecosystems and social safety. Environmentally friendly algae-inhibiting methods utilizing allelopathic substances offer advantages such as convenient application and low costs, presenting a bright application prospect in the fields of water and ecological restoration. This study aimed to investigate the procedure for extracting total flavonoids from Zanthoxylum bungeanum leaves and assess allelopathic mechanism of Z. bungeanum leaf extracts on Microcystis aeruginosa. The optimal extraction conditions were determined as follows: solvent-to-material ratio = 10 mL/g; extraction time = 55 min; ethanol volume fraction = 80%; and ultrasonic temperature = 80 °C. Antioxidant activity tests revealed that Z. bungeanum leaf extracts exhibit superior capacity compared to Butylated hydroxytoluene (BHT) but inferior to Vitamin C (VC). Moreover, high-concentration Z. bungeanum leaf extracts can disrupt the structures of oxygen-evolving complexes at the donor sides of photosystem II (PSII) reaction center and influence energy distribution at PSII reaction centers, thereby inhibiting electron transmission activities at both donor and receptor sides of the PSII reaction center. The elucidated allelopathic mechanism of Z. bungeanum leaf extracts provides theoretical evidence for the algal-bloom control and the development of allelopathic algae-inhibiting agents, offering a reference for the further comprehensive development and utilization of Z. bungeanum.</p>","PeriodicalId":11360,"journal":{"name":"Current Microbiology","volume":"82 1","pages":"48"},"PeriodicalIF":2.3,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142853524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Tridax procumbens Secondary Metabolites Anti-Tuberculosis Activity by In Vitro and In Silico Methods.","authors":"Jayashri Seetharaman, R Akshaya Priya, Reya Rene Philip, M Muthuraj, D Sankari","doi":"10.1007/s00284-024-04033-9","DOIUrl":"10.1007/s00284-024-04033-9","url":null,"abstract":"<p><p>Mycobacterium tuberculosis is a human pathogen that causes Tuberculosis (TB) disease. Researchers have reported the activity of traditional medicinal plants against human pathogens. However, antimycobacterial studies of medicinal plants against M. tuberculosis remain limited. Thus, the purpose of this study is to characterize the phytochemical profile, antibacterial and antimycobacterial activity of Tridax procumbens towards H37Rv. The antibacterial activity was elucidated by the inhibitory zone formed around the disc by performing disk diffusion method. Tridax antimycobacterial activity measured by Microplate Alamar Blue Assay (MABA) infers the sample is sensitive to H37Rv at MIC (minimum inhibitory concentration) 600 µg/mL. BACTEC MGIT 960 DST identifies the sample is susceptible to H37Rv and Rifampicin resistant (RR). Antiproliferative, functional group determination and mechanism of action of secondary metabolites were performed by MTT, Fourier transform infrared spectroscopy (FTIR) and Gas Chromatography-mass spectrometry (GC-MS). The phytocompounds antimycobacterial efficacy is further supported by molecular docking data. The binding interactions of ligands with gyrA gene revealed (S,Z)-Heptadeca-1,9-dien-4,6-diyn-3-ol molecule as a prominent phytocompound with a binding affinity of -6.6 kcal/mol.</p>","PeriodicalId":11360,"journal":{"name":"Current Microbiology","volume":"82 1","pages":"50"},"PeriodicalIF":2.3,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142863476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deciphering the Antimicrobial and Antibiofilm Efficiency of Thyme Essential Oil Encapsulated Zeolitic Imidazole Framework-8 Against Foodborne Pathogens.","authors":"Suganathan Muthalagu, Suganthy Natarajan","doi":"10.1007/s00284-024-04025-9","DOIUrl":"10.1007/s00284-024-04025-9","url":null,"abstract":"<p><p>Food Packaging using antibacterial substances plays a vital role in food industry in controlling contamination caused by food borne pathogens. Stability and pH dependent degradation characteristics of zeolitic imidazole framework-8 (ZIF-8) makes its suitable candidate for biomedical applications. The present study focuses on thyme essential oil (TEO) encapsulated in ZIF-8 to achieve a synergistic antibacterial effect and prolonged drug release, aiming to extend the shelf life of food products. Optical, structural and surface characterizations of TEO encapsulated within ZIF-8 (ZIF-8@TEO) reveals successful incorporation of TEO into ZIF-8 nanoparticles. High drug loading and pH dependent release rate with higher release rate at acidic condition (75%) makes ZIF-8 a promising drug delivery system. ZIF-8@TEO exhibited potent antimicrobial against Staphylococcus aureus, Bacillus subtilius and Pseudomonas aeruginosa, also attenuated the biofilm forming ability of these food borne pathogens. In vitro and in vivo toxicity studies reveal the non-hemolytic and non-toxic nature indicating its biocompatible nature. The results of the study reveal that ZIF-8@TEO nanoconjugate can be used for the development of novel antibacterial nanocomposite-based films for food packaging applications.</p>","PeriodicalId":11360,"journal":{"name":"Current Microbiology","volume":"82 1","pages":"49"},"PeriodicalIF":2.3,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142863454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation, Structure, and Biological Activities of Exopolysaccharides from Actinomycetes: A Review.","authors":"Xiao-Lian Wei, Song-Yi Mo, Rola Ali-Saeed, Hong Zeng","doi":"10.1007/s00284-024-03999-w","DOIUrl":"10.1007/s00284-024-03999-w","url":null,"abstract":"<p><p>In recent years, exopolysaccharides (EPSs) from actinomycetes have become a significant focus of research due to their diverse biological activities, including antitumor, antiviral, and immunoregulatory effects. This article reviews recent advancements in the study of EPSs from actinomycetes, summarizing findings from existing literature on extraction methods, structural characteristics, and biological activities. Various extraction methods can impact the purity and quality of EPSs obtained from actinomycetes. In addition, EPSs produced by different species of actinomycetes exhibit diverse structures, leading to variations in their biological activities. Future research should focus on optimizing current extraction methods or developing new techniques, exploring the relationship between structural characteristics and biological activities of EPSs, and elucidating their molecular mechanisms of action. Such efforts are essential for the comprehensive study and potential applications of EPSs from actinomycetes.</p>","PeriodicalId":11360,"journal":{"name":"Current Microbiology","volume":"82 1","pages":"45"},"PeriodicalIF":2.3,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142845820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occurrence, Multidrug Resistance, SCCmec Typing of Methicillin-Resistant Staphylococcus aureus from Farmed Eggs and Environment.","authors":"Shumaila Taskeen, Randhir Singh, Jasbir Singh Bedi, Anil Kumar Arora, Rabinder Singh Aulakh, Jaswinder Singh","doi":"10.1007/s00284-024-04020-0","DOIUrl":"10.1007/s00284-024-04020-0","url":null,"abstract":"<p><p>A comparative cross-sectional study was conducted on farmed eggs (n: 480) and environmental samples (n: 72; feed, water, and poultry droppings) from twenty-four deep litter and caged poultry layer farms across Punjab, India. The study noted a significantly higher occurrence of Staphylococcus aureus (31.67%; 95% CI 26.37-36.96%) and methicillin-resistant S. aureus (MRSA) (32.5%, 95% CI 23-43.3%) in deep litter farms (P < 0.05). The logistic regression analysis revealed while the odds of presumptive MRSA from egg isolates were high (Odds ratio: 2.714; 95% CI 1.172, 6.284) in deep litter, conversely, resistance against ceftriaxone (0.279; 95% CI 0.129, 0.605), tetracycline (0.227; 95% CI 0.104, 0.497), and erythromycin (0.46; 95% CI 0.218, 0.973) was low. The multi-drug resistance was high and nearly equal; 68.53%, and 72.22% in deep litter and cage systems respectively. Additionally, around 89.65% and 77.7% of MRSA from deep litter and cage systems had multiple antibiotic resistance index > 0.2 respectively. Among the resistance genes under study, the odds of mecA and tetL were 2.417 and 8.029 times higher in deep litter. The hierarchical clustering of MRSA isolates based on the antibiogram profile depicted the formation of a large number of cluster solutions with a mix of isolates from both systems. The SCCmec typing revealed a predominance of type V in both the systems (34.4%; deep litter and 33.3%; cage), with a scarce distribution of other types and subtypes viz., deep litter: types III; 13.7%, IVc; 6.8%, II; 6.8%, IVa, and IVb; 3.4% and cage system: types III and IVc; 11.1%. To, the best of our knowledge current study is the first-ever comprehensive study on comparative occurrence, AMR profile, molecular characterization, and typing of MRSA from farmed eggs and environment from India.</p>","PeriodicalId":11360,"journal":{"name":"Current Microbiology","volume":"82 1","pages":"47"},"PeriodicalIF":2.3,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142845868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CRISPR/Cas9-Engineering for Increased Amylolytic Potential of Microbes for Sustainable Wastewater Treatment: A Review.","authors":"Yatika Dixit, Preeti Yadav, Hitakshi Asnani, Arun Kumar Sharma","doi":"10.1007/s00284-024-04024-w","DOIUrl":"10.1007/s00284-024-04024-w","url":null,"abstract":"<p><p>Amylases are pivotal enzymes with extensive industrial applications, including food processing, textile manufacturing, pharmaceuticals, and biofuel production. Traditional methods for enhancing amylase production in microbial strains often lack precision and efficiency. The advent of CRISPR/Cas9 technology has revolutionized genetic engineering, offering precise and targeted modifications to microbial genomes. This review explores the potential of CRISPR/Cas9 for improving amylase production, highlighting its advantages over conventional methods. This review discusses the mechanism of CRISPR/Cas9, the identification and targeting of key genes involved in amylase synthesis and regulation, and the optimization of expression systems. Additionally, current review examines case studies demonstrating successful CRISPR/Cas9 applications in various microbial hosts. The review also delves into the integration of CRISPR/Cas9 in wastewater treatment, where genetically engineered amylolytic strains enhance the degradation of complex organic pollutants. Despite the promising prospects, challenges such as off-target effects and regulatory considerations remain. This review provides a comprehensive overview of the current advancements, challenges, and future directions in the application of CRISPR/Cas9 technology for amylase production and environmental biotechnology.</p>","PeriodicalId":11360,"journal":{"name":"Current Microbiology","volume":"82 1","pages":"44"},"PeriodicalIF":2.3,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142845848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expression of Multiple Copies of the Lon Protease Gene Resulted in Increased Antibiotic Production, Osmotic and UV Stress Resistance in Streptomyces coelicolor A3(2).","authors":"Halil Yilmaz, Emine Yaradir, Sedef Tunca","doi":"10.1007/s00284-024-04021-z","DOIUrl":"10.1007/s00284-024-04021-z","url":null,"abstract":"<p><p>The genus Streptomyces is a group of gram-positive bacteria that exhibit a distinctive growth pattern characterised by elongated, branched hyphae. Streptomyces coelicolor A3(2), which produces at least five different antibiotics, is a model organism that is widely used in genetic studies. There are very few studies in Streptomyces on the ATP-dependent Lon protease, which has very important functions in every organism and is particularly responsible for protein homeostasis. The aim of this study was to construct and characterize a recombinant S. coelicolor strain expressing the lon gene on a multicopy plasmid. For this purpose, the lon gene was first cloned in Escherichia coli under the control of the glycerol-inducible promoter of pSPG, and its expression in S. coelicolor A3(2) cells was demonstrated by RT-qPCR. In contrast with the initial hypothesis, increased lon expression did not affect cell growth seriously. Instead, it increased the cell's tolerance to osmotic and UV stress and led to a significant increase in antibiotic production. The recombinant strain produced 27 times more actinorhodin and 43 times more undecylprodigiosin than the wild-type strain after 120 h of fermentation. To our knowledge, this is the first study to demonstrate the effects of expression of the lon gene on a high copy number plasmid in Streptomyces.</p>","PeriodicalId":11360,"journal":{"name":"Current Microbiology","volume":"82 1","pages":"43"},"PeriodicalIF":2.3,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142845791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}