Pub Date : 2024-05-29eCollection Date: 2024-01-01DOI: 10.1093/ismeco/ycae075
Samantha L Goldman, Jon G Sanders, Daniel D Sprockett, Abigail Landers, Weiwei Yan, Andrew H Moeller
Shotgun metagenomic sequencing provides valuable insights into microbial communities, but the high cost of library preparation with standard kits and protocols is a barrier for many. New methods such as Hackflex use diluted commercially available reagents to greatly reduce library preparation costs. However, these methods have not been systematically validated for metagenomic sequencing. Here, we evaluate Hackflex performance by sequencing metagenomic libraries from known mock communities as well as mouse fecal samples prepared by Hackflex, Illumina DNA Prep, and Illumina TruSeq methods. Hackflex successfully recovered all members of the Zymo mock community, performing best for samples with DNA concentrations <1 ng/μL. Furthermore, Hackflex was able to delineate microbiota of individual inbred mice from the same breeding stock at the same mouse facility, and statistical modeling indicated that mouse ID explained a greater fraction of the variance in metagenomic composition than did library preparation method. These results show that Hackflex is suitable for generating inventories of bacterial communities through metagenomic sequencing.
霰弹枪元基因组测序技术为深入了解微生物群落提供了宝贵的资料,但使用标准试剂盒和方案制备文库的高昂成本却成为许多人的障碍。Hackflex 等新方法使用稀释的市售试剂,大大降低了文库制备成本。然而,这些方法尚未在元基因组测序中得到系统的验证。在这里,我们通过对来自已知模拟群落以及用 Hackflex、Illumina DNA Prep 和 Illumina TruSeq 方法制备的小鼠粪便样本的元基因组文库进行测序,来评估 Hackflex 的性能。Hackflex 成功地恢复了 Zymo 模拟群落的所有成员,在 DNA 浓度为 0.5%的样本中表现最佳。
{"title":"Hackflex library preparation enables low-cost metagenomic profiling.","authors":"Samantha L Goldman, Jon G Sanders, Daniel D Sprockett, Abigail Landers, Weiwei Yan, Andrew H Moeller","doi":"10.1093/ismeco/ycae075","DOIUrl":"10.1093/ismeco/ycae075","url":null,"abstract":"<p><p>Shotgun metagenomic sequencing provides valuable insights into microbial communities, but the high cost of library preparation with standard kits and protocols is a barrier for many. New methods such as Hackflex use diluted commercially available reagents to greatly reduce library preparation costs. However, these methods have not been systematically validated for metagenomic sequencing. Here, we evaluate Hackflex performance by sequencing metagenomic libraries from known mock communities as well as mouse fecal samples prepared by Hackflex, Illumina DNA Prep, and Illumina TruSeq methods. Hackflex successfully recovered all members of the Zymo mock community, performing best for samples with DNA concentrations <1 ng/μL. Furthermore, Hackflex was able to delineate microbiota of individual inbred mice from the same breeding stock at the same mouse facility, and statistical modeling indicated that mouse ID explained a greater fraction of the variance in metagenomic composition than did library preparation method. These results show that Hackflex is suitable for generating inventories of bacterial communities through metagenomic sequencing.</p>","PeriodicalId":73516,"journal":{"name":"ISME communications","volume":"4 1","pages":"ycae075"},"PeriodicalIF":5.1,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11190725/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141443868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As diazotrophic cyanobacteria of tremendous biomass, Trichodesmium continuously provide a nitrogen source for carbon-fixing cyanobacteria and drive the generation of primary productivity in marine environments. However, ocean iron deficiencies limit growth and metabolism of Trichodesmium. Recent studies have shown the co-occurrence of Trichodesmium and siderophore-producing Synechococcus in iron-deficient oceans, but whether siderophores secreted by Synechococcus can be used by Trichodesmium to adapt to iron deficiency is not clear. We constructed a mutant Synechococcus strain unable to produce siderophores to explore this issue. Synechococcus filtrates with or without siderophores were added into a Trichodesmium microbial consortium consisting of Trichodesmium erythraeum IMS 101 as the dominant microbe with chronic iron deficiency. By analyzing the physiological phenotype, metagenome, and metatranscriptome, we investigated the interactions between the nitrogen-fixing cyanobacterium Tricodesmium and siderophore-producing cyanobacterium Synechococcus under conditions of iron deficiency. The results indicated that siderophores secreted by Synechococcus are likely to chelate with free iron in the culture medium of the Trichodesmium consortium, reducing the concentration of bioavailable iron and posing greater challenges to the absorption of iron by Trichodesmium. These findings revealed the characteristics of iron-competitive utilization between diazotrophic cyanobacteria and siderophore-producing cyanobacteria, as well as potential interactions, and provide a scientific basis for understanding the regulatory effects of nutrient limitation on marine primary productivity.
{"title":"Interactions between the nitrogen-fixing cyanobacterium <i>Trichodesmium</i> and siderophore-producing cyanobacterium <i>Synechococcus</i> under iron limitation.","authors":"Xumei Sun, Yan Xiao, Chengwen Yong, Hansheng Sun, Shuangqing Li, Hailong Huang, Haibo Jiang","doi":"10.1093/ismeco/ycae072","DOIUrl":"10.1093/ismeco/ycae072","url":null,"abstract":"<p><p>As diazotrophic cyanobacteria of tremendous biomass, <i>Trichodesmium</i> continuously provide a nitrogen source for carbon-fixing cyanobacteria and drive the generation of primary productivity in marine environments. However, ocean iron deficiencies limit growth and metabolism of <i>Trichodesmium</i>. Recent studies have shown the co-occurrence of <i>Trichodesmium</i> and siderophore-producing <i>Synechococcus</i> in iron-deficient oceans, but whether siderophores secreted by <i>Synechococcus</i> can be used by <i>Trichodesmium</i> to adapt to iron deficiency is not clear. We constructed a mutant <i>Synechococcus</i> strain unable to produce siderophores to explore this issue. <i>Synechococcus</i> filtrates with or without siderophores were added into a <i>Trichodesmium</i> microbial consortium consisting of Trichodesmium erythraeum IMS 101 as the dominant microbe with chronic iron deficiency. By analyzing the physiological phenotype, metagenome, and metatranscriptome, we investigated the interactions between the nitrogen-fixing cyanobacterium <i>Tricodesmium</i> and siderophore-producing cyanobacterium <i>Synechococcus</i> under conditions of iron deficiency. The results indicated that siderophores secreted by <i>Synechococcus</i> are likely to chelate with free iron in the culture medium of the <i>Trichodesmium</i> consortium, reducing the concentration of bioavailable iron and posing greater challenges to the absorption of iron by <i>Trichodesmium</i>. These findings revealed the characteristics of iron-competitive utilization between diazotrophic cyanobacteria and siderophore-producing cyanobacteria, as well as potential interactions, and provide a scientific basis for understanding the regulatory effects of nutrient limitation on marine primary productivity.</p>","PeriodicalId":73516,"journal":{"name":"ISME communications","volume":"4 1","pages":"ycae072"},"PeriodicalIF":0.0,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11171426/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141319089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-09eCollection Date: 2024-01-01DOI: 10.1093/ismeco/ycae064
Jennifer L Goff, Lauren M Lui, Torben N Nielsen, Farris L Poole, Heidi J Smith, Kathleen F Walker, Terry C Hazen, Matthew W Fields, Adam P Arkin, Michael W W Adams
Mobile genetic elements (MGEs) like plasmids, viruses, and transposable elements can provide fitness benefits to their hosts for survival in the presence of environmental stressors. Heavy metal resistance genes (HMRGs) are frequently observed on MGEs, suggesting that MGEs may be an important driver of adaptive evolution in environments contaminated with heavy metals. Here, we report the meta-mobilome of the heavy metal-contaminated regions of the Oak Ridge Reservation subsurface. This meta-mobilome was compared with one derived from samples collected from unimpacted regions of the Oak Ridge Reservation subsurface. We assembled 1615 unique circularized DNA elements that we propose to be MGEs. The circular elements from the highly contaminated subsurface were enriched in HMRG clusters relative to those from the nearby unimpacted regions. Additionally, we found that these HMRGs were associated with Gamma and Betaproteobacteria hosts in the contaminated subsurface and potentially facilitate the persistence and dominance of these taxa in this region. Finally, the HMRGs were associated with conjugative elements, suggesting their potential for future lateral transfer. We demonstrate how our understanding of MGE ecology, evolution, and function can be enhanced through the genomic context provided by completed MGE assemblies.
{"title":"Mixed waste contamination selects for a mobile genetic element population enriched in multiple heavy metal resistance genes.","authors":"Jennifer L Goff, Lauren M Lui, Torben N Nielsen, Farris L Poole, Heidi J Smith, Kathleen F Walker, Terry C Hazen, Matthew W Fields, Adam P Arkin, Michael W W Adams","doi":"10.1093/ismeco/ycae064","DOIUrl":"10.1093/ismeco/ycae064","url":null,"abstract":"<p><p>Mobile genetic elements (MGEs) like plasmids, viruses, and transposable elements can provide fitness benefits to their hosts for survival in the presence of environmental stressors. Heavy metal resistance genes (HMRGs) are frequently observed on MGEs, suggesting that MGEs may be an important driver of adaptive evolution in environments contaminated with heavy metals. Here, we report the meta-mobilome of the heavy metal-contaminated regions of the Oak Ridge Reservation subsurface. This meta-mobilome was compared with one derived from samples collected from unimpacted regions of the Oak Ridge Reservation subsurface. We assembled 1615 unique circularized DNA elements that we propose to be MGEs. The circular elements from the highly contaminated subsurface were enriched in HMRG clusters relative to those from the nearby unimpacted regions. Additionally, we found that these HMRGs were associated with Gamma and Betaproteobacteria hosts in the contaminated subsurface and potentially facilitate the persistence and dominance of these taxa in this region. Finally, the HMRGs were associated with conjugative elements, suggesting their potential for future lateral transfer. We demonstrate how our understanding of MGE ecology, evolution, and function can be enhanced through the genomic context provided by completed MGE assemblies.</p>","PeriodicalId":73516,"journal":{"name":"ISME communications","volume":"4 1","pages":"ycae064"},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11128244/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141155249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-08eCollection Date: 2024-01-01DOI: 10.1093/ismeco/ycae070
Yanchen Sun, Yongchao Yin, Guang He, Gyuhyon Cha, Héctor L Ayala-Del-Río, Grizelle González, Konstantinos T Konstantinidis, Frank E Löffler
Nitrous oxide (N2O), a greenhouse gas with ozone destruction potential, is mitigated by the microbial reduction to dinitrogen catalyzed by N2O reductase (NosZ). Bacteria with NosZ activity have been studied at circumneutral pH but the microbiology of low pH N2O reduction has remained elusive. Acidic (pH < 5) tropical forest soils were collected in the Luquillo Experimental Forest in Puerto Rico, and microcosms maintained with low (0.02 mM) and high (2 mM) N2O assessed N2O reduction at pH 4.5 and 7.3. All microcosms consumed N2O, with lag times of up to 7 months observed in microcosms with 2 mM N2O. Comparative metagenome analysis revealed that Rhodocyclaceae dominated in circumneutral microcosms under both N2O feeding regimes. At pH 4.5, Peptococcaceae dominated in high-N2O, and Hyphomicrobiaceae in low-N2O microcosms. Seventeen high-quality metagenome-assembled genomes (MAGs) recovered from the N2O-reducing microcosms harbored nos operons, with all eight MAGs derived from acidic microcosms carrying the Clade II type nosZ and lacking nitrite reductase genes (nirS/K). Five of the eight MAGs recovered from pH 4.5 microcosms represent novel taxa indicating an unexplored N2O-reducing diversity exists in acidic tropical soils. A survey of pH 3.5-5.7 soil metagenome datasets revealed that nosZ genes commonly occur, suggesting broad distribution of N2O reduction potential in acidic soils.
{"title":"pH selects for distinct N<sub>2</sub>O-reducing microbiomes in tropical soil microcosms.","authors":"Yanchen Sun, Yongchao Yin, Guang He, Gyuhyon Cha, Héctor L Ayala-Del-Río, Grizelle González, Konstantinos T Konstantinidis, Frank E Löffler","doi":"10.1093/ismeco/ycae070","DOIUrl":"10.1093/ismeco/ycae070","url":null,"abstract":"<p><p>Nitrous oxide (N<sub>2</sub>O), a greenhouse gas with ozone destruction potential, is mitigated by the microbial reduction to dinitrogen catalyzed by N<sub>2</sub>O reductase (NosZ). Bacteria with NosZ activity have been studied at circumneutral pH but the microbiology of low pH N<sub>2</sub>O reduction has remained elusive. Acidic (pH < 5) tropical forest soils were collected in the Luquillo Experimental Forest in Puerto Rico, and microcosms maintained with low (0.02 mM) and high (2 mM) N<sub>2</sub>O assessed N<sub>2</sub>O reduction at pH 4.5 and 7.3. All microcosms consumed N<sub>2</sub>O, with lag times of up to 7 months observed in microcosms with 2 mM N<sub>2</sub>O. Comparative metagenome analysis revealed that <i>Rhodocyclaceae</i> dominated in circumneutral microcosms under both N<sub>2</sub>O feeding regimes. At pH 4.5, <i>Peptococcaceae</i> dominated in high-N<sub>2</sub>O, and <i>Hyphomicrobiaceae</i> in low-N<sub>2</sub>O microcosms. Seventeen high-quality metagenome-assembled genomes (MAGs) recovered from the N<sub>2</sub>O-reducing microcosms harbored <i>nos</i> operons, with all eight MAGs derived from acidic microcosms carrying the Clade II type <i>nosZ</i> and lacking nitrite reductase genes (<i>nirS</i>/<i>K</i>). Five of the eight MAGs recovered from pH 4.5 microcosms represent novel taxa indicating an unexplored N<sub>2</sub>O-reducing diversity exists in acidic tropical soils. A survey of pH 3.5-5.7 soil metagenome datasets revealed that <i>nosZ</i> genes commonly occur, suggesting broad distribution of N<sub>2</sub>O reduction potential in acidic soils.</p>","PeriodicalId":73516,"journal":{"name":"ISME communications","volume":"4 1","pages":"ycae070"},"PeriodicalIF":0.0,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11131594/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141163210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01eCollection Date: 2024-01-01DOI: 10.1093/ismeco/ycae063
Tong Wang, Leyuan Li, Daniel Figeys, Yang-Yu Liu
The genome of a microorganism encodes its potential functions that can be implemented through expressed proteins. It remains elusive how a protein's selective expression depends on its metabolic essentiality to microbial growth or its ability to claim resources as ecological niches. To reveal a protein's metabolic or ecological role, we developed a computational pipeline, which pairs metagenomics and metaproteomics data to quantify each protein's gene-level and protein-level functional redundancy simultaneously. We first illustrated the idea behind the pipeline using simulated data of a consumer-resource model. We then validated it using real data from human and mouse gut microbiome samples. In particular, we analyzed ABC-type transporters and ribosomal proteins, confirming that the metabolic and ecological roles predicted by our pipeline agree well with prior knowledge. Finally, we performed in vitro cultures of a human gut microbiome sample and investigated how oversupplying various sugars involved in ecological niches influences the community structure and protein abundance. The presented results demonstrate the performance of our pipeline in identifying proteins' metabolic and ecological roles, as well as its potential to help us design nutrient interventions to modulate the human microbiome.
{"title":"Pairing metagenomics and metaproteomics to characterize ecological niches and metabolic essentiality of gut microbiomes.","authors":"Tong Wang, Leyuan Li, Daniel Figeys, Yang-Yu Liu","doi":"10.1093/ismeco/ycae063","DOIUrl":"10.1093/ismeco/ycae063","url":null,"abstract":"<p><p>The genome of a microorganism encodes its potential functions that can be implemented through expressed proteins. It remains elusive how a protein's selective expression depends on its metabolic essentiality to microbial growth or its ability to claim resources as ecological niches. To reveal a protein's metabolic or ecological role, we developed a computational pipeline, which pairs metagenomics and metaproteomics data to quantify each protein's gene-level and protein-level functional redundancy simultaneously. We first illustrated the idea behind the pipeline using simulated data of a consumer-resource model. We then validated it using real data from human and mouse gut microbiome samples. In particular, we analyzed ABC-type transporters and ribosomal proteins, confirming that the metabolic and ecological roles predicted by our pipeline agree well with prior knowledge. Finally, we performed <i>in vitro</i> cultures of a human gut microbiome sample and investigated how oversupplying various sugars involved in ecological niches influences the community structure and protein abundance. The presented results demonstrate the performance of our pipeline in identifying proteins' metabolic and ecological roles, as well as its potential to help us design nutrient interventions to modulate the human microbiome.</p>","PeriodicalId":73516,"journal":{"name":"ISME communications","volume":"4 1","pages":"ycae063"},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11131966/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141163079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-19eCollection Date: 2024-01-01DOI: 10.1093/ismeco/ycae057
James D Brunner, Aaron J Robinson, Patrick S G Chain
Microbial communities are diverse biological systems that include taxa from across multiple kingdoms of life. Notably, interactions between bacteria and fungi play a significant role in determining community structure. However, these statistical associations across kingdoms are more difficult to infer than intra-kingdom associations due to the nature of the data involved using standard network inference techniques. We quantify the challenges of cross-kingdom network inference from both theoretical and practical points of view using synthetic and real-world microbiome data. We detail the theoretical issue presented by combining compositional data sets drawn from the same environment, e.g. 16S and ITS sequencing of a single set of samples, and we survey common network inference techniques for their ability to handle this error. We then test these techniques for the accuracy and usefulness of their intra- and inter-kingdom associations by inferring networks from a set of simulated samples for which a ground-truth set of associations is known. We show that while the two methods mitigate the error of cross-kingdom inference, there is little difference between techniques for key practical applications including identification of strong correlations and identification of possible keystone taxa (i.e. hub nodes in the network). Furthermore, we identify a signature of the error caused by transkingdom network inference and demonstrate that it appears in networks constructed using real-world environmental microbiome data.
微生物群落是一个多样化的生物系统,包括来自多个生命领域的类群。值得注意的是,细菌和真菌之间的相互作用在决定群落结构方面发挥着重要作用。然而,由于使用标准网络推断技术所涉及数据的性质,这些跨生物界的统计关联比生物界内的关联更难推断。我们利用合成和真实世界的微生物组数据,从理论和实践角度量化了跨王国网络推断所面临的挑战。我们详细介绍了将来自同一环境的组成数据集(如单个样本集的 16S 和 ITS 测序)结合起来所带来的理论问题,并考察了常见网络推断技术处理这一误差的能力。然后,我们通过从一组已知关联的模拟样本中推断网络,测试这些技术在内部和部门间关联方面的准确性和实用性。我们发现,虽然这两种方法都能减少跨领域推断的误差,但在关键的实际应用中,包括识别强相关性和识别可能的基石类群(即网络中的枢纽节点)方面,这两种技术的差别并不大。此外,我们还发现了跨王国网络推断所造成的误差特征,并证明它出现在使用真实世界环境微生物组数据构建的网络中。
{"title":"Combining compositional data sets introduces error in covariance network reconstruction.","authors":"James D Brunner, Aaron J Robinson, Patrick S G Chain","doi":"10.1093/ismeco/ycae057","DOIUrl":"10.1093/ismeco/ycae057","url":null,"abstract":"<p><p>Microbial communities are diverse biological systems that include taxa from across multiple kingdoms of life. Notably, interactions between bacteria and fungi play a significant role in determining community structure. However, these statistical associations across kingdoms are more difficult to infer than intra-kingdom associations due to the nature of the data involved using standard network inference techniques. We quantify the challenges of cross-kingdom network inference from both theoretical and practical points of view using synthetic and real-world microbiome data. We detail the theoretical issue presented by combining compositional data sets drawn from the same environment, e.g. 16S and ITS sequencing of a single set of samples, and we survey common network inference techniques for their ability to handle this error. We then test these techniques for the accuracy and usefulness of their intra- and inter-kingdom associations by inferring networks from a set of simulated samples for which a ground-truth set of associations is known. We show that while the two methods mitigate the error of cross-kingdom inference, there is little difference between techniques for key practical applications including identification of strong correlations and identification of possible keystone taxa (i.e. hub nodes in the network). Furthermore, we identify a signature of the error caused by transkingdom network inference and demonstrate that it appears in networks constructed using real-world environmental microbiome data.</p>","PeriodicalId":73516,"journal":{"name":"ISME communications","volume":"4 1","pages":"ycae057"},"PeriodicalIF":0.0,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11135214/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141176745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Candidatus Accumulibacter, a key genus of polyphosphate-accumulating organisms, plays key roles in lab- and full-scale enhanced biological phosphorus removal (EBPR) systems. A total of 10 high-quality Ca. Accumulibacter genomes were recovered from EBPR systems operated at high temperatures, providing significantly updated phylogenetic and genomic insights into the Ca. Accumulibacter lineage. Among these genomes, clade IIF members SCELSE-3, SCELSE-4, and SCELSE-6 represent the to-date known genomes encoding a complete denitrification pathway, suggesting that Ca. Accumulibacter alone could achieve complete denitrification. Clade IIC members SSA1, SCUT-1, SCELCE-2, and SCELSE-8 lack the entire set of denitrifying genes, representing to-date known non-denitrifying Ca. Accumulibacter. A pan-genomic analysis with other Ca. Accumulibacter members suggested that all Ca. Accumulibacter likely has the potential to use dicarboxylic amino acids. Ca. Accumulibacter aalborgensis AALB and Ca. Accumulibacter affinis BAT3C720 seemed to be the only two members capable of using glucose for EBPR. A heat shock protein Hsp20 encoding gene was found exclusively in genomes recovered at high temperatures, which was absent in clades IA, IC, IG, IIA, IIB, IID, IIG, and II-I members. High transcription of this gene in clade IIC members SCUT-2 and SCUT-3 suggested its role in surviving high temperatures for Ca. Accumulibacter. Ambiguous clade identity was observed for newly recovered genomes (SCELSE-9 and SCELSE-10). Five machine learning models were developed using orthogroups as input features. Prediction results suggested that they belong to a new clade (IIK). The phylogeny of Ca. Accumulibacter was re-evaluated based on the laterally derived polyphosphokinase 2 gene, showing improved resolution in differentiating different clades.
{"title":"Two new clades recovered at high temperatures provide novel phylogenetic and genomic insights into <i>Candidatus</i> Accumulibacter.","authors":"Xiaojing Xie, Xuhan Deng, Jinling Chen, Liping Chen, Jing Yuan, Hang Chen, Chaohai Wei, Xianghui Liu, Guanglei Qiu","doi":"10.1093/ismeco/ycae049","DOIUrl":"10.1093/ismeco/ycae049","url":null,"abstract":"<p><p><i>Candidatus</i> Accumulibacter, a key genus of polyphosphate-accumulating organisms, plays key roles in lab- and full-scale enhanced biological phosphorus removal (EBPR) systems. A total of 10 high-quality <i>Ca</i>. Accumulibacter genomes were recovered from EBPR systems operated at high temperatures, providing significantly updated phylogenetic and genomic insights into the <i>Ca</i>. Accumulibacter lineage. Among these genomes, clade IIF members SCELSE-3, SCELSE-4, and SCELSE-6 represent the to-date known genomes encoding a complete denitrification pathway, suggesting that <i>Ca</i>. Accumulibacter alone could achieve complete denitrification. Clade IIC members SSA1, SCUT-1, SCELCE-2, and SCELSE-8 lack the entire set of denitrifying genes, representing to-date known non-denitrifying <i>Ca</i>. Accumulibacter. A pan-genomic analysis with other <i>Ca</i>. Accumulibacter members suggested that all <i>Ca</i>. Accumulibacter likely has the potential to use dicarboxylic amino acids. <i>Ca</i>. Accumulibacter aalborgensis AALB and <i>Ca</i>. Accumulibacter affinis BAT3C720 seemed to be the only two members capable of using glucose for EBPR. A heat shock protein Hsp20 encoding gene was found exclusively in genomes recovered at high temperatures, which was absent in clades IA, IC, IG, IIA, IIB, IID, IIG, and II-I members. High transcription of this gene in clade IIC members SCUT-2 and SCUT-3 suggested its role in surviving high temperatures for <i>Ca</i>. Accumulibacter. Ambiguous clade identity was observed for newly recovered genomes (SCELSE-9 and SCELSE-10). Five machine learning models were developed using orthogroups as input features. Prediction results suggested that they belong to a new clade (IIK). The phylogeny of <i>Ca</i>. Accumulibacter was re-evaluated based on the laterally derived polyphosphokinase 2 gene, showing improved resolution in differentiating different clades.</p>","PeriodicalId":73516,"journal":{"name":"ISME communications","volume":"4 1","pages":"ycae049"},"PeriodicalIF":0.0,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11131965/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141163080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-15eCollection Date: 2024-01-01DOI: 10.1093/ismeco/ycae055
Solène L Y Moulin, Sarah Frail, Thomas Braukmann, Jon Doenier, Melissa Steele-Ogus, Jane C Marks, Matthew M Mills, Ellen Yeh
Epithemia spp. diatoms contain obligate, nitrogen-fixing endosymbionts, or diazoplasts, derived from cyanobacteria. These algae are a rare example of photosynthetic eukaryotes that have successfully coupled oxygenic photosynthesis with oxygen-sensitive nitrogenase activity. Here, we report a newly-isolated species, E. clementina, as a model to investigate endosymbiotic acquisition of nitrogen fixation. We demonstrate that the diazoplast, which has lost photosynthesis, provides fixed nitrogen to the diatom host in exchange for fixed carbon. To identify the metabolic changes associated with this endosymbiotic specialization, we compared the Epithemia diazoplast with its close, free-living cyanobacterial relative, Crocosphaera subtropica. Unlike C. subtropica, in which nitrogenase activity is temporally separated from photosynthesis, we show that nitrogenase activity in the diazoplast is continuous through the day (concurrent with host photosynthesis) and night. Host and diazoplast metabolism are tightly coupled to support nitrogenase activity: Inhibition of photosynthesis abolishes daytime nitrogenase activity, while nighttime nitrogenase activity no longer requires cyanobacterial glycogen storage pathways. Instead, import of host-derived carbohydrates supports nitrogenase activity throughout the day-night cycle. Carbohydrate metabolism is streamlined in the diazoplast compared to C. subtropica with retention of the oxidative pentose phosphate pathway and oxidative phosphorylation. Similar to heterocysts, these pathways may be optimized to support nitrogenase activity, providing reducing equivalents and ATP and consuming oxygen. Our results demonstrate that the diazoplast is specialized for endosymbiotic nitrogen fixation. Altogether, we establish a new model for studying endosymbiosis, perform a functional characterization of this diazotroph endosymbiosis, and identify metabolic adaptations for endosymbiotic acquisition of a critical biological function.
Epithemia spp.硅藻含有来自蓝藻的强制性固氮内共生体或重氮体。这些藻类是光合真核生物中成功将含氧光合作用与氧敏感的氮酶活性结合起来的罕见例子。在这里,我们报告了一个新分离出来的物种--克莱门特藻(E. clementina),并将其作为研究内共生获得固氮作用的模型。我们证明,失去光合作用的重氮质体向硅藻宿主提供固定氮以交换固定碳。为了确定与这种内共生特化相关的代谢变化,我们将重氮原生质表皮藻与其近亲、自由生活的蓝藻--亚热带栉水母(Crocosphaera subtropica)进行了比较。与亚热带蓝藻不同的是,重氮质体中的氮酶活动与光合作用在时间上是分离的,而我们的研究表明,重氮质体中的氮酶活动在白天(与寄主光合作用同时进行)和夜间都是持续进行的。宿主和重氮酵母的新陈代谢紧密耦合,以支持氮酶的活性:抑制光合作用会取消白天的氮酶活性,而夜间的氮酶活性不再需要蓝藻糖原储存途径。相反,在整个昼夜周期中,宿主碳水化合物的输入支持着氮酶的活性。与亚热带蓝藻相比,重氮藻体中的碳水化合物代谢得到了简化,保留了磷酸戊糖氧化途径和氧化磷酸化作用。与杂囊类似,这些途径可能经过优化,以支持氮酶活性,提供还原当量和 ATP 并消耗氧气。我们的研究结果表明,重氮质体专门用于内共生固氮。总之,我们建立了一个研究内共生的新模型,对这种重氮内共生进行了功能表征,并确定了内共生获得关键生物功能的代谢适应性。
{"title":"The endosymbiont of <i>Epithemia clementina</i> is specialized for nitrogen fixation within a photosynthetic eukaryote.","authors":"Solène L Y Moulin, Sarah Frail, Thomas Braukmann, Jon Doenier, Melissa Steele-Ogus, Jane C Marks, Matthew M Mills, Ellen Yeh","doi":"10.1093/ismeco/ycae055","DOIUrl":"10.1093/ismeco/ycae055","url":null,"abstract":"<p><p><i>Epithemia</i> spp. diatoms contain obligate, nitrogen-fixing endosymbionts, or diazoplasts, derived from cyanobacteria. These algae are a rare example of photosynthetic eukaryotes that have successfully coupled oxygenic photosynthesis with oxygen-sensitive nitrogenase activity. Here, we report a newly-isolated species, <i>E. clementina</i>, as a model to investigate endosymbiotic acquisition of nitrogen fixation. We demonstrate that the diazoplast, which has lost photosynthesis, provides fixed nitrogen to the diatom host in exchange for fixed carbon. To identify the metabolic changes associated with this endosymbiotic specialization, we compared the <i>Epithemia</i> diazoplast with its close, free-living cyanobacterial relative, <i>Crocosphaera subtropica</i>. Unlike <i>C. subtropica</i>, in which nitrogenase activity is temporally separated from photosynthesis, we show that nitrogenase activity in the diazoplast is continuous through the day (concurrent with host photosynthesis) and night. Host and diazoplast metabolism are tightly coupled to support nitrogenase activity: Inhibition of photosynthesis abolishes daytime nitrogenase activity, while nighttime nitrogenase activity no longer requires cyanobacterial glycogen storage pathways. Instead, import of host-derived carbohydrates supports nitrogenase activity throughout the day-night cycle. Carbohydrate metabolism is streamlined in the diazoplast compared to <i>C. subtropica</i> with retention of the oxidative pentose phosphate pathway and oxidative phosphorylation. Similar to heterocysts, these pathways may be optimized to support nitrogenase activity, providing reducing equivalents and ATP and consuming oxygen. Our results demonstrate that the diazoplast is specialized for endosymbiotic nitrogen fixation. Altogether, we establish a new model for studying endosymbiosis, perform a functional characterization of this diazotroph endosymbiosis, and identify metabolic adaptations for endosymbiotic acquisition of a critical biological function.</p>","PeriodicalId":73516,"journal":{"name":"ISME communications","volume":"4 1","pages":"ycae055"},"PeriodicalIF":0.0,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11070190/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140869764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-15eCollection Date: 2024-01-01DOI: 10.1093/ismeco/ycae053
Víctor Hugo Jarquín-Díaz, Susana Carolina Martins Ferreira, Alice Balard, Ľudovít Ďureje, Milos Macholán, Jaroslav Piálek, Johan Bengtsson-Palme, Stephanie Kramer-Schadt, Sofia Kirke Forslund-Startceva, Emanuel Heitlinger
Antibiotic resistance is a priority public health problem resulting from eco-evolutionary dynamics within microbial communities and their interaction at a mammalian host interface or geographical scale. The links between mammalian host genetics, bacterial gut community, and antimicrobial resistance gene (ARG) content must be better understood in natural populations inhabiting heterogeneous environments. Hybridization, the interbreeding of genetically divergent populations, influences different components of the gut microbial communities. However, its impact on bacterial traits such as antibiotic resistance is unknown. Here, we present that hybridization might shape bacterial communities and ARG occurrence. We used amplicon sequencing to study the gut microbiome and to predict ARG composition in natural populations of house mice (Mus musculus). We compared gastrointestinal bacterial and ARG diversity, composition, and abundance across a gradient of pure and hybrid genotypes in the European House Mouse Hybrid Zone. We observed an increased overall predicted richness of ARG in hybrid mice. We found bacteria-ARG interactions by their co-abundance and detected phenotypes of extreme abundances in hybrid mice at the level of specific bacterial taxa and ARGs, mainly multidrug resistance genes. Our work suggests that mammalian host genetic variation impacts the gut microbiome and chromosomal ARGs. However, it raises further questions on how the mammalian host genetics impact ARGs via microbiome dynamics or environmental covariates.
{"title":"Aberrant microbiomes are associated with increased antibiotic resistance gene load in hybrid mice.","authors":"Víctor Hugo Jarquín-Díaz, Susana Carolina Martins Ferreira, Alice Balard, Ľudovít Ďureje, Milos Macholán, Jaroslav Piálek, Johan Bengtsson-Palme, Stephanie Kramer-Schadt, Sofia Kirke Forslund-Startceva, Emanuel Heitlinger","doi":"10.1093/ismeco/ycae053","DOIUrl":"10.1093/ismeco/ycae053","url":null,"abstract":"<p><p>Antibiotic resistance is a priority public health problem resulting from eco-evolutionary dynamics within microbial communities and their interaction at a mammalian host interface or geographical scale. The links between mammalian host genetics, bacterial gut community, and antimicrobial resistance gene (ARG) content must be better understood in natural populations inhabiting heterogeneous environments. Hybridization, the interbreeding of genetically divergent populations, influences different components of the gut microbial communities. However, its impact on bacterial traits such as antibiotic resistance is unknown. Here, we present that hybridization might shape bacterial communities and ARG occurrence. We used amplicon sequencing to study the gut microbiome and to predict ARG composition in natural populations of house mice (<i>Mus musculus</i>). We compared gastrointestinal bacterial and ARG diversity, composition, and abundance across a gradient of pure and hybrid genotypes in the European House Mouse Hybrid Zone. We observed an increased overall predicted richness of ARG in hybrid mice. We found bacteria-ARG interactions by their co-abundance and detected phenotypes of extreme abundances in hybrid mice at the level of specific bacterial taxa and ARGs, mainly multidrug resistance genes. Our work suggests that mammalian host genetic variation impacts the gut microbiome and chromosomal ARGs. However, it raises further questions on how the mammalian host genetics impact ARGs via microbiome dynamics or environmental covariates.</p>","PeriodicalId":73516,"journal":{"name":"ISME communications","volume":"4 1","pages":"ycae053"},"PeriodicalIF":0.0,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11128261/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141155248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-15eCollection Date: 2024-01-01DOI: 10.1093/ismeco/ycae054
Justin Maire, Astrid Collingro, Matthias Horn, Madeleine J H van Oppen
Cnidarians, such as corals and sea anemones, associate with a wide range of bacteria that have essential functions, including nutrient cycling and the production of antimicrobial compounds. Within cnidarians, bacteria can colonize all microhabitats including the tissues. Among them are obligate intracellular bacteria of the phylum Chlamydiota (chlamydiae) whose impact on cnidarian hosts and holobionts, especially corals, remain unknown. Here, we conducted a meta-analysis of previously published 16S rRNA gene metabarcoding data from cnidarians (e.g. coral, jellyfish, and anemones), eight metagenome-assembled genomes (MAGs) of coral-associated chlamydiae, and one MAG of jellyfish-associated chlamydiae to decipher their diversity and functional potential. While the metabarcoding dataset showed an enormous diversity of cnidarian-associated chlamydiae, six out of nine MAGs were affiliated with the Simkaniaceae family. The other three MAGs were assigned to the Parasimkaniaceae, Rhabdochlamydiaceae, and Anoxychlamydiaceae, respectively. All MAGs lacked the genes necessary for an independent existence, lacking any nucleotide or vitamin and most amino acid biosynthesis pathways. Hallmark chlamydial genes, such as a type III secretion system, nucleotide transporters, and genes for host interaction, were encoded in all MAGs. Together these observations suggest an obligate intracellular lifestyle of coral-associated chlamydiae. No unique genes were found in coral-associated chlamydiae, suggesting a lack of host specificity. Additional studies are needed to understand how chlamydiae interact with their coral host, and other microbes in coral holobionts. This first study of the diversity and functional potential of coral-associated chlamydiae improves our understanding of both the coral microbiome and the chlamydial lifestyle and host range.
{"title":"Chlamydiae in corals: shared functional potential despite broad taxonomic diversity.","authors":"Justin Maire, Astrid Collingro, Matthias Horn, Madeleine J H van Oppen","doi":"10.1093/ismeco/ycae054","DOIUrl":"https://doi.org/10.1093/ismeco/ycae054","url":null,"abstract":"<p><p>Cnidarians, such as corals and sea anemones, associate with a wide range of bacteria that have essential functions, including nutrient cycling and the production of antimicrobial compounds. Within cnidarians, bacteria can colonize all microhabitats including the tissues. Among them are obligate intracellular bacteria of the phylum Chlamydiota (chlamydiae) whose impact on cnidarian hosts and holobionts, especially corals, remain unknown. Here, we conducted a meta-analysis of previously published 16S rRNA gene metabarcoding data from cnidarians (e.g. coral, jellyfish, and anemones), eight metagenome-assembled genomes (MAGs) of coral-associated chlamydiae, and one MAG of jellyfish-associated chlamydiae to decipher their diversity and functional potential. While the metabarcoding dataset showed an enormous diversity of cnidarian-associated chlamydiae, six out of nine MAGs were affiliated with the Simkaniaceae family. The other three MAGs were assigned to the Parasimkaniaceae, Rhabdochlamydiaceae, and Anoxychlamydiaceae, respectively. All MAGs lacked the genes necessary for an independent existence, lacking any nucleotide or vitamin and most amino acid biosynthesis pathways. Hallmark chlamydial genes, such as a type III secretion system, nucleotide transporters, and genes for host interaction, were encoded in all MAGs. Together these observations suggest an obligate intracellular lifestyle of coral-associated chlamydiae. No unique genes were found in coral-associated chlamydiae, suggesting a lack of host specificity. Additional studies are needed to understand how chlamydiae interact with their coral host, and other microbes in coral holobionts. This first study of the diversity and functional potential of coral-associated chlamydiae improves our understanding of both the coral microbiome and the chlamydial lifestyle and host range.</p>","PeriodicalId":73516,"journal":{"name":"ISME communications","volume":"4 1","pages":"ycae054"},"PeriodicalIF":0.0,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11070183/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140853788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}