Microbial Ecology最新文献

{"title":"Gut fungal diversity across different life stages of the onion fly Delia antiqua","authors":"Xin Cao, Miaomiao Li, Xiaoqing Wu, Susu Fan, Luyao Lin, Linfeng Xu, Xinjian Zhang, Fangyuan Zhou","doi":"10.1007/s00248-024-02431-x","DOIUrl":"https://doi.org/10.1007/s00248-024-02431-x","url":null,"abstract":"<p>A significant number of microorganisms inhabit the intestinal tract or the body surface of insects. While the majority of research on insect microbiome interaction has mainly focused on bacteria, of late multiple studies have been acknowledging the importance of fungi and have started reporting the fungal communities as well. In this study, high-throughput sequencing was used to compare the diversity of intestinal fungi in <i>Delia antiqua</i> (Diptera: Anthomyiidae) at different growth stages, and effect of differential fungi between adjacent life stages on the growth and development of <i>D. antiqua</i> was investigated<i>.</i> The results showed that there were significant differences in the α and β diversity of gut fungal communities between two adjacent growth stages. Among the dominant fungi, genera <i>Penicillium</i> and <i>Meyerozyma</i> and family Cordycipitaceae had higher abundances. Cordycipitaceae was mainly enriched in the pupal and adult (male and female) stages, <i>Penicillium</i> was mainly enriched in the pupal, 2nd instar and 3rd instar larval stages, and <i>Meyerozyma</i> was enriched in the pupal stage. Only three fungal species were found to differ between two adjacent growth stages. These three fungal species including <i>Fusarium oxysporum</i>, <i>Meyerozyma guilliermondii</i> and <i>Penicillium roqueforti</i> generally inhibited the growth and development of <i>D. antiqua</i>, with only <i>P. roqueforti</i> promoting the growth and development of female insects. This study will provide theoretical support for the search for new pathogenic microorganisms for other fly pests control and the development of new biological control strategies for fly pests.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3><p>Three fungal species were found to differ between two adjacent growth stages. These three fungal species including <i>Fusarium oxysporum</i>, <i>Meyerozyma guilliermondii</i> and <i>Penicillium roqueforti</i> generally inhibited the growth and development of <i>D. antiqua</i>, with only <i>P. roqueforti</i> promoting the growth and development of female insects.</p>\u0000","PeriodicalId":18708,"journal":{"name":"Microbial Ecology","volume":"5 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218541","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":"Nutritional Quality of Basal Resource in Stream Food Webs Increased with Light Reduction—Implications for Riparian Revegetation","authors":"Ke Zhang, Xiang Tan, Quanfa Zhang","doi":"10.1007/s00248-024-02432-w","DOIUrl":"https://doi.org/10.1007/s00248-024-02432-w","url":null,"abstract":"<p>Biofilms are considered a basal resource with high nutritional quality in stream food webs, as periphytic algae are abundant of polyunsaturated fatty acids (PUFAs). PUFAs are essential for growth and reproduction of consumers who cannot or have very limited capacity to biosynthesize. Yet, how the nutritional quality based on PUFA of basal food sources changes with light intensity remains unclear. We conducted a manipulative experiment in mesocosms to explore the response and mechanisms of nutritional quality to shading, simulating riparian restoration. We found a significant increase in PUFA% (including arachidonic acid, ARA) under shading conditions. The increased PUFA is caused by the algal community succession from Cyanobacteria and Chlorophyta to Bacillariophyta which is abundant of PUFA (especially eicosapentaenoic acid, EPA; docosahexaenoic acid, DHA). On the other hand, shading increased PUFA via upregulating enzymes such as Δ12 desaturase (FAD2, EC:1.14.19.6) and 3-ketoacyl-CoA synthase (KCS, EC:2.3.1.199) in the biosynthesis of unsaturated fatty acid elongation pathways. Our findings imply that riparian reforestation by decreasing light intensity increases the nutritional quality of basal resources in streams, which may enhance transfer of good quality carbon to consumers in higher trophic levels through bottom-up effects.</p>","PeriodicalId":18708,"journal":{"name":"Microbial Ecology","volume":"4 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218569","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":"Plant G × Microbial E: Plant Genotype Interaction with Soil Bacterial Community Shapes Rhizosphere Composition During Invasion","authors":"Mae Berlow, Miles Mesa, Mikayla Creek, Jesse G. Duarte, Elizabeth Carpenter, Brandon Phinizy, Krikor Andonian, Katrina M. Dlugosch","doi":"10.1007/s00248-024-02429-5","DOIUrl":"https://doi.org/10.1007/s00248-024-02429-5","url":null,"abstract":"<p>It is increasingly recognized that different genetic variants of hosts can uniquely shape their microbiomes. Invasive species often evolve in their introduced ranges, but little is known about the potential for their microbial associations to change during invasion as a result. We asked whether host genotype (G), microbial environment (E), or their interaction (G × E) affected the composition and diversity of host-associated microbiomes in <i>Centaurea solstitialis</i> (yellow starthistle), a Eurasian plant that is known to have evolved novel genotypes and phenotypes and to have altered microbial interactions, in its severe invasion of CA, USA. We conducted an experiment in which native and invading plant genotypes were inoculated with native and invaded range soil microbial communities. We used amplicon sequencing to characterize rhizosphere bacteria in both the experiment and the field soils from which they were derived. We found that native and invading plant genotypes accumulated different microbial associations at the family level in each soil community, often counter to differences in family abundance between soil communities. Root associations with potentially beneficial Streptomycetaceae were particularly interesting, as these were more abundant in the invaded range field soil and accumulated on invading genotypes. We also found that bacterial diversity is higher in invaded soils, but that invading genotypes accumulated a lower diversity of bacteria and unique microbial composition in experimental inoculations, relative to native genotypes. Thus variation in microbial associations of invaders was driven by the interaction of plant G and microbial E, and rhizosphere microbial communities appear to change in composition in response to host evolution during invasion.</p>","PeriodicalId":18708,"journal":{"name":"Microbial Ecology","volume":"20 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218542","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":"Geographical, Seasonal, and Growth-Related Dynamics of Gut Microbiota in a Grapevine Pest, Apolygus spinolae (Heteroptera: Miridae).","authors":"Hiroyuki Morimura, Kota Ishigami, Tomoyuki Sato, Teruo Sone, Yoshitomo Kikuchi","doi":"10.1007/s00248-024-02426-8","DOIUrl":"10.1007/s00248-024-02426-8","url":null,"abstract":"<p><p>A number of insects are associated with gut symbiotic microorganisms, wherein symbiotic partners play pivotal metabolic roles for each other such as nutrient supplementation, diet degradation, and pesticide detoxification. Despite the ecological and evolutionary importance of gut microbial communities in insects, their diversity and dynamics remain unclear in many species. The green plant bug Apolygus spinolae, a notorious grapevine pest in Japan, damages grape shoots and severely reduces grape berry yield and quality. The plant bug possesses a simple tubular gut housing ~ 10⁴ bacteria. Here, we investigated geographic, seasonal, and growth-related dynamics of gut microbiota by high-throughput sequencing in 82 individuals (11 nymphs and 71 adults) from five locations in Hokkaido, Japan. In plant bugs, gut microbiota changed dynamically depending on region, season, and developmental stage. Among the gut bacteria, Serratia was consistently and abundantly detected and was significantly affected by seasonal changes. In addition, Caballeronia, known as a specific symbiont in some stinkbug species, was abundantly detected, especially in insects collected in late summer despite A. spinolae complete lack of midgut crypts known as symbiotic organ harboring Caballeronia in other stinkbug species. Considering their prevalence among host bug populations, it is possible these gut microorganisms play a pivotal role in the adaptation of the green plant bug to grapevine fields, although further confirmation through rearing experiments is needed.</p>","PeriodicalId":18708,"journal":{"name":"Microbial Ecology","volume":"87 1","pages":"112"},"PeriodicalIF":3.3,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11383845/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142154570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Detoxifying Substances on Uranium Removal by Bacteria Isolated from Mine Soils: Performance, Mechanisms, and Bacterial Communities.","authors":"Xin Song, Jun Li, Zhiyu Xiong, Haichao Sha, Guohua Wang, Qin Liu, Taotao Zeng","doi":"10.1007/s00248-024-02428-6","DOIUrl":"10.1007/s00248-024-02428-6","url":null,"abstract":"<p><p>In this study, we investigated the effect of detoxifying substances on U(VI) removal by bacteria isolated from mine soil. The results demonstrated that the highest U(VI) removal efficiency (85.6%) was achieved at pH 6.0 and a temperature of 35 °C, with an initial U(VI) concentration of 10 mg/L. For detoxifying substances, signaling molecules acyl homoserine lactone (AHLs, 0.1 µmol/L), anthraquinone-2, 6-disulfonic acid (AQDS, 1 mmol/L), reduced glutathione (GSH, 0.1 mmol/L), selenium (Se, 1 mg/L), montmorillonite (MT, 1 g/L), and ethylenediaminetetraacetic acid (EDTA, 0.1 mmol/L) substantially enhanced the bacterial U(VI) removal by 34.9%, 37.4%, 54.5%, 35.1%, 32.8%, and 47.8% after 12 h, respectively. This was due to the alleviation of U(VI) toxicity in bacteria through detoxifying substances, as evidenced by lower malondialdehyde (MDA) content and higher superoxide dismutase (SOD) and catalase (CAT) activities for bacteria exposed to U(VI) and detoxifying substances, compared to those exposed to U(VI) alone. FTIR results showed that hydroxyl, carboxyl, phosphorus, and amide groups participated in the U(VI) removal. After exposure to U(VI), the relative abundances of Chryseobacterium and Stenotrophomonas increased by 48.5% and 12.5%, respectively, suggesting their tolerance ability to U(VI). Gene function prediction further demonstrated that the detoxifying substances AHLs alleviate U(VI) toxicity by influencing bacterial metabolism. This study suggests the potential application of detoxifying substances in the U(VI)-containing wastewater treatment through bioremediation.</p>","PeriodicalId":18708,"journal":{"name":"Microbial Ecology","volume":"87 1","pages":"111"},"PeriodicalIF":3.3,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11374843/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142133201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Abrolhos Nominally Herbivorous Coral Reef Fish Acanthurus chirurgus, Kyphosus sp., Scarus trispinosus, and Sparisoma axillare Have Similarities in Feeding But Species-Specific Microbiomes.","authors":"Cristiane Thompson, Raphael Silva, Fernando Z Gibran, Leonardo Bacha, Mayanne A M de Freitas, Mateus Thompson, Felipe Landuci, Diogo Tschoeke, Xiao-Hua Zhang, Xiaolei Wang, Wenbin Zhao, Pedro Vianna Gatts, Marcelo Gomes de Almeida, Carlos Eduardo de Rezende, Fabiano Thompson","doi":"10.1007/s00248-024-02423-x","DOIUrl":"10.1007/s00248-024-02423-x","url":null,"abstract":"<p><p>Coral reefs rely heavily on reef fish for their health, yet overfishing has resulted in their decline, leading to an increase in fast-growing algae and changes in reef ecosystems, a phenomenon described as the phase-shift. A clearer understanding of the intricate interplay between herbivorous, their food, and their gut microbiomes could enhance reef health. This study examines the gut microbiome and isotopic markers (δ¹³C and δ¹⁵N) of four key nominally herbivorous reef fish species (Acanthurus chirurgus, Kyphosus sp., Scarus trispinosus, and Sparisoma axillare) in the Southwestern Atlantic's Abrolhos Reef systems. Approximately 16.8 million 16S rRNA sequences were produced for the four fish species, with an average of 317,047 ± 57,007 per species. Bacteria such as Proteobacteria, Firmicutes, and Cyanobacteria were prevalent in their microbiomes. These fish show unique microbiomes that result from co-diversification, diet, and restricted movement. Coral-associated bacteria (Endozoicomonas, Rhizobia, and Ruegeria) were found in abundance in the gut contents of the parrotfish species Sc. trispinosus and Sp. axillare. These parrotfishes could aid coral health by disseminating such beneficial bacteria across the reef. Meanwhile, Kyphosus sp. predominantly had Pirellulaceae and Rhodobacteraceae. Four fish species had a diet composed of turf components (filamentous Cyanobacteria) and brown algae (Dictyopteris). They also had similar isotopic niches, suggesting they shared food sources. A significant difference was observed between the isotopic signature of fish muscular gut tissue and gut contents, pointing to the role that host genetics and gut microbes play in differentiating fish tissues.</p>","PeriodicalId":18708,"journal":{"name":"Microbial Ecology","volume":"87 1","pages":"110"},"PeriodicalIF":3.3,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11365853/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142109571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mating Assay: Plating Below a Cell Density Threshold is Required for Unbiased Estimation of Plasmid Conjugation Frequency of RP4 Transfer Between E. coli Strains.","authors":"Zhiming He, Barth F Smets, Arnaud Dechesne","doi":"10.1007/s00248-024-02427-7","DOIUrl":"10.1007/s00248-024-02427-7","url":null,"abstract":"<p><p>Mating assays are common laboratory experiments for measuring the conjugation frequency, i.e. efficiency at which a plasmid transfers from a population of donor cells to a population of recipient cells. Selective plating remains a widely used quantification method to enumerate transconjugants at the end of such assays. However, conjugation frequencies may be inaccurately estimated because plasmid transfer can occur on transconjugant-selective plates rather than only during the intended mating duration. We investigated the influence of cell density on this phenomenon. We conducted mating experiments with IncPα plasmid RP4 harbored in Escherichia coli at a fixed cell density and mating conditions, inoculated a serial dilution of the mating mixture on transconjugant-selective plates or in transconjugant-selective broth, and compared the results to a model of cell-to-cell distance distribution. Our findings suggest that irrespective of the mating mode (liquid vs solid), the enumeration of transconjugants becomes significantly biased if the plated cell density exceeds 28 Colony Forming Unit (CFU)/mm² (or 1.68•10⁵ CFU/standard 9 cm Petri dish). This threshold is determined with a 95% confidence interval of ± 4 CFU/mm² (± 2.46•10⁴ CFU/standard 9 cm Petri dish). Liquid mating assays were more sensitive to this bias because the conjugation frequency of RP4 is several orders of magnitude lower in suspension compared to surface mating. Therefore, if selective plating is used, we recommend to plate at this density threshold and that negative controls are performed where donors and recipients are briefly mixed before plating at the same dilutions as for the actual mating assay. As an alternative, a liquid enumeration method can be utilized to increase the signal-to-noise ratio and allow for more accurate enumeration of transconjugants.</p>","PeriodicalId":18708,"journal":{"name":"Microbial Ecology","volume":"87 1","pages":"109"},"PeriodicalIF":3.3,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11358341/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142093539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Implications of Domestication in Theobroma cacao L. Seed-Borne Microbial Endophytes Diversity.","authors":"Deisy Lisseth Toloza-Moreno, Roxana Yockteng, José Ives Pérez-Zuñiga, Cristian Salinas-Castillo, Alejandro Caro-Quintero","doi":"10.1007/s00248-024-02409-9","DOIUrl":"10.1007/s00248-024-02409-9","url":null,"abstract":"<p><p>The study of plant-microbe interactions is a rapidly growing research field, with increasing attention to the role of seed-borne microbial endophytes in protecting the plant during its development from abiotic and biotic stresses. Recent evidence suggests that seed microbiota is crucial in establishing the plant microbial community, affecting its composition and structure, and influencing plant physiology and ecology. For Theobroma cacao L., the diversity and composition of vertically transmitted microbes have yet to be addressed in detail. We explored the composition and diversity of seed-borne endophytes in cacao pods of commercial genotypes (ICS95, IMC67), recently liberated genotypes from AGROSAVIA (TCS01, TCS19), and landraces from Tumaco (Colombia) (AC9, ROS1, ROS2), to evaluate microbial vertical transmission and establishment in various tissues during plant development. We observed a higher abundance of Pseudomonas and Pantoea genera in the landraces and AGROSAVIA genotypes, while the commercial genotypes presented a higher number of bacteria species but in low abundance. In addition, all the genotypes and plant tissues showed a high percentage of fungi of the genus Penicillium. These results indicate that domestication in cacao has increased bacterial endophyte diversity but has reduced their abundance. We isolated some of these seed-borne endophytes to evaluate their potential as growth promoters and found that Bacillus, Pantoea, and Pseudomonas strains presented high production of indole acetic acid and ACC deaminase activity. Our results suggest that cacao domestication could lead to the loss of essential bacteria for seedling establishment and development. This study improves our understanding of the relationship and interaction between perennial plants and seed-borne microbiota.</p>","PeriodicalId":18708,"journal":{"name":"Microbial Ecology","volume":"87 1","pages":"108"},"PeriodicalIF":3.3,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11358227/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142080888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 the Microbial Diversity and Composition of Three Cigar Product Categories.","authors":"Sanjay Joshi, Kent Pham, Luke Moe, Ruth McNees","doi":"10.1007/s00248-024-02425-9","DOIUrl":"10.1007/s00248-024-02425-9","url":null,"abstract":"<p><p>Cigars and cigarillos are emerging as popular tobacco alternatives to cigarettes. However, these products may be equally harmful to human health than cigarettes and are associated with similar adverse health effects. We used 16S rRNA gene amplicon sequencing to extensively characterize the microbial diversity and investigate differences in microbial composition across 23 different products representing three different cigar product categories: filtered cigar, cigarillo, and large cigar. High throughput sequencing of the V4 hypervariable region of the 16 s rRNA gene revealed 2124 Operational Taxonomic Units (OTUs). Our findings showed that the three categories of cigars differed significantly in observed richness and Shannon diversity, with filtered cigars exhibiting lower diversity compared to large cigars and cigarillos. We also found a shared and unique microbiota among different product types. Firmicutes was the most abundant phylum in all product categories, followed by Actinobacteria. Among the 16 genera shared across all product types were Bacillus, Staphylococcus, Pseudomonas, and Pantoea. Nine genera were exclusively shared by large cigars and cigarillos and an additional thirteen genera were exclusive to filtered cigars. Analysis of individual cigar products showed consistent microbial composition across replicates for most large cigars and cigarillos while filtered cigars showed more inter-product variability. These findings provide important insights into the microbial diversity of the different cigar product types.</p>","PeriodicalId":18708,"journal":{"name":"Microbial Ecology","volume":"87 1","pages":"107"},"PeriodicalIF":3.3,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11335948/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142004806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen Fixation and Microbial Communities Associated with Decomposing Seagrass Leaves in Temperate Coastal Waters.","authors":"Vasiliki Papazachariou, Victor Fernández-Juárez, Laura Wegener Parfrey, Lasse Riemann","doi":"10.1007/s00248-024-02424-w","DOIUrl":"10.1007/s00248-024-02424-w","url":null,"abstract":"<p><p>Seagrass meadows play pivotal roles in coastal biochemical cycles, with nitrogen fixation being a well-established process associated with living seagrass. Here, we tested the hypothesis that nitrogen fixation is also associated with seagrass debris in Danish coastal waters. We conducted a 52-day in situ experiment to investigate nitrogen fixation (proxied by acetylene reduction) and dynamics of the microbial community (16S rRNA gene amplicon sequencing) and the nitrogen fixing community (nifH DNA/RNA amplicon sequencing) associated with decomposing Zostera marina leaves. The leaves harboured distinct microbial communities, including distinct nitrogen fixers, relative to the surrounding seawater and sediment throughout the experiment. Nitrogen fixation rates were measurable on most days, but highest on days 3 (dark, 334.8 nmol N g^-1 dw h^-1) and 15 (light, 194.6 nmol N g^-1 dw h^-1). Nitrogen fixation rates were not correlated with the concentration of inorganic nutrients in the surrounding seawater or with carbon:nitrogen ratios in the leaves. The composition of nitrogen fixers shifted from cyanobacterial Sphaerospermopsis to heterotrophic genera like Desulfopila over the decomposition period. On the days with highest fixation, nifH RNA gene transcripts were mainly accounted for by cyanobacteria, in particular by Sphaerospermopsis and an unknown taxon (order Nostocales), alongside Proteobacteria. Our study shows that seagrass debris in temperate coastal waters harbours substantial nitrogen fixation carried out by cyanobacteria and heterotrophic bacteria that are distinct relative to the surrounding seawater and sediments. This suggests that seagrass debris constitutes a selective environment where degradation is affected by the import of nitrogen via nitrogen fixation.</p>","PeriodicalId":18708,"journal":{"name":"Microbial Ecology","volume":"87 1","pages":"106"},"PeriodicalIF":3.3,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11324715/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141976095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}