Analysis of carbohydrate-active enzymes in Thermogemmatispora sp. strain T81 reveals carbohydrate degradation ability

2018 ◽  
Vol 64 (12) ◽  
pp. 992-1003 ◽  
Author(s):  
Atilio Tomazini ◽  
Sadhana Lal ◽  
Riffat Munir ◽  
Matthew Stott ◽  
Bernard Henrissat ◽  
...  

The phylum Chloroflexi is phylogenetically diverse and is a deeply branching lineage of bacteria that express a broad spectrum of physiological and metabolic capabilities. Members of the order Ktedonobacteriales, including the families Ktedonobacteriaceae, Thermosporotrichaceae, and Thermogemmatisporaceae, all have flexible aerobic metabolisms capable of utilizing a wide range of carbohydrates. A number of species within these families are considered cellulolytic and are capable of using cellulose as a sole carbon and energy source. In contrast, Ktedonobacter racemifer, the type strain of the order, does not appear to possess this cellulolytic phenotype. In this study, we confirmed the ability of Thermogemmatispora sp. strain T81 to hydrolyze cellulose, determined the whole-genome sequence of Thermogemmatispora sp. T81, and using comparative bioinformatics analyses, identified genes encoding putative carbohydrate-active enzymes (CAZymes) in the Thermogemmatispora sp. T81, Thermogemmatispora onikobensis, and Ktedonobacter racemifer genomes. Analyses of the Thermogemmatispora sp. T81 genome identified 64 CAZyme gene sequences belonging to 57 glycoside hydrolase families. The genome of Thermogemmatispora sp. T81 encodes 19 genes for putative extracellular CAZymes, similar to the number of putative extracellular CAZymes identified in T. onikobensis (17) and K. racemifer (17), despite K. racemifer not possessing a cellulolytic phenotype. These results suggest that these members of the order Ktedonobacteriales may use a broader range of carbohydrate polymers than currently described.

2018 ◽  
Vol 85 (3) ◽  
Author(s):  
Nikola Palevich ◽  
William J. Kelly ◽  
Siva Ganesh ◽  
Jasna Rakonjac ◽  
Graeme T. Attwood

ABSTRACTRumen bacterial species belonging to the genusButyrivibrioare important degraders of plant polysaccharides, particularly hemicelluloses (arabinoxylans) and pectin. Currently, four species are recognized; they have very similar substrate utilization profiles, but little is known about how these microorganisms are able to coexist in the rumen. To investigate this question,Butyrivibrio hungateiMB2003 andButyrivibrio proteoclasticusB316Twere grown alone or in coculture on xylan or pectin, and their growth, release of sugars, fermentation end products, and transcriptomes were examined. In monocultures, B316Twas able to grow well on xylan and pectin, while MB2003 was unable to utilize either of these insoluble substrates to support significant growth. Cocultures of B316Tgrown with MB2003 revealed that MB2003 showed growth almost equivalent to that of B316Twhen either xylan or pectin was supplied as the substrate. The effect of coculture on the transcriptomes of B316Tand MB2003 was assessed; B316Ttranscription was largely unaffected by the presence of MB2003, but MB2003 expressed a wide range of genes encoding proteins for carbohydrate degradation, central metabolism, oligosaccharide transport, and substrate assimilation, in order to compete with B316Tfor the released sugars. These results suggest that B316Thas a role as an initiator of primary solubilization of xylan and pectin, while MB2003 competes effectively for the released soluble sugars to enable its growth and maintenance in the rumen.IMPORTANCEFeeding a future global population of 9 billion people and climate change are the primary challenges facing agriculture today. Ruminant livestock are important food-producing animals, and maximizing their productivity requires an understanding of their digestive systems and the roles played by rumen microbes in plant polysaccharide degradation.Butyrivibriospecies are a phylogenetically diverse group of bacteria and are commonly found in the rumen, where they are a substantial source of polysaccharide-degrading enzymes for the depolymerization of lignocellulosic material. Our findings suggest that closely related species ofButyrivibriohave developed unique strategies for the degradation of plant fiber and the subsequent assimilation of carbohydrates in order to coexist in the competitive rumen environment. The identification of genes expressed during these competitive interactions gives further insight into the enzymatic machinery used by these bacteria as they degrade the xylan and pectin components of plant fiber.


PLoS ONE ◽  
2014 ◽  
Vol 9 (8) ◽  
pp. e104260 ◽  
Author(s):  
Riffat I. Munir ◽  
John Schellenberg ◽  
Bernard Henrissat ◽  
Tobin J. Verbeke ◽  
Richard Sparling ◽  
...  

2019 ◽  
Author(s):  
Marcin Brzozowski ◽  
Joanna Barbara Jursa-Kulesza ◽  
Danuta Kosik-Bogacka

Abstract Background Pseudomonas aeruginosa is a pathogen capable of causing a wide range of severe opportunistic infections. Its genome contains numerous virulence genes encoding secretion systems of different types, structures responsible for adhesion and motility, toxins, proteases, siderophores, and others. The aim of this study is to analyse virulence, population structure, and distribution of highly divergent genes among 81 P. aeruginosa strains available in whole genome sequence databases. Results For this purpose, 260 virulence genes were searched in 81 different P. aeruginosa whole genomes that were available in databases. We identified most of the virulence genes as core and softcore genes. The most of the highly divergent sequences encoding pyoverdines, flagella and pilA were acknowledged as accessory, because of the differences in sequence among different alleles of those genes. Phylogenetic tree revealed the existence of three genetic groups of P. aeruginosa. Strains of the first clade were characterised as ExoS positive, whiles genomes of the second clade were ExoU positive. The member of third clade, PA7 strain was the only strain deprived of all T3SS genes. The analysis of pyoverdine locus facilitated finding a new pyoverdine type similar to pyoverdine type III. This newly described variant was present in 7 different strains. It contained a gene that was probably created by the fusion of pilD and pilI genes. In order to determine the coexistence of genes encoding exoenzymes, flagella and pyoverdines, Pearson correlation coefficients were calculated. There were significant correlations between genes encoding ExoS/ExoU-type strains and genes encoding type-A/type-B flagella. The correlation also occurred between Conclusion This study facilitates describing genetic differences of various P. aeruginosa strains based on Pseudomonas aeruginosa whole genome information from online databases. We conclude that most P. aeruginosa virulence genes are present in more than 95% of available genomes of the species. There are correlations of occurrence of different P. aeruginosa accessory virulence genes.


2021 ◽  
Author(s):  
Philipp Resl ◽  
Adina R. Bujold ◽  
Gulnara Tagirdzhanova ◽  
Peter Meidl ◽  
Sandra Freire Rallo ◽  
...  

Lichen symbioses are generally thought to be stabilized by the transfer of fixed carbon compounds from a photosynthesizing unicellular symbiont to a fungus. In other fungal symbioses, carbohydrate subsidies correlate with genomic reductions in the number of genes for plant cell wall-degrading enzymes (PCWDEs), but whether this is the case with lichen fungal symbionts (LFSs) is unknown. We predicted genes encoding carbohydrate-active enzymes (CAZymes) and sugar transporters in 17 existing and 29 newly sequenced genomes from across the class Lecanoromycetes, the largest extant clade of LFSs. Despite possessing lower mean numbers of PCWDE genes compared to non-symbiont Ascomycota, all LFS genomes possessed a robust suite of predicted PCWDEs. The largest CAZyme gene numbers, on par with model species such as Penicillium, were retained in genomes from the subclass Ostropomycetidae, which are found in crust lichens with highly specific ecologies. The lowest numbers were in the subclass Lecanoromycetidae, which are symbionts of many generalist macrolichens. Our results suggest that association with phototroph symbionts does not in itself result in functional loss of PCWDEs and that PCWDE losses may have been driven by adaptive processes within the evolution of specific LFS lineages. The inferred capability of some LFSs to access a wide range of carbohydrates suggests that some lichen symbioses may augment fixed CO2 with carbon from external sources.


2018 ◽  
Author(s):  
Nikola Palevich ◽  
William J. Kelly ◽  
Siva Ganesh ◽  
Jasna Rakonjac ◽  
Graeme T. Attwood

ABSTRACTRumen bacterial species belonging to the generaButyrivibrioare important degraders of plant polysaccharides, particularly hemicelluloses (arabinoxylans) and pectin. Currently, four distinct species are recognized which have very similar substrate utilization profiles, but little is known about how these microorganisms are able to co-exist in the rumen. To investigate this question,Butyrivibrio hungatei(MB2003) andButyrivibrio proteoclasticus(B316T) were grown alone or in co-culture on the insoluble substrates, xylan or pectin, and their growth, release of sugars, fermentation end products and transcriptomes were examined. In single cultures, B316Twas able to degrade and grow well on xylan and pectin, whileB. hungateiMB2003 was unable to utilize either of these insoluble substrates to support significant growth. Co-cultures of B316Tgrown with MB2003 revealed that MB2003 showed almost equivalent growth to B316Twhen either xylan or pectin were supplied as substrates. The effect of co-culture on the transcriptomes of B316Tand MB2003 was very marked; B316Ttranscription was largely unaffected by the presence MB2003, but MB2003 expressed a wide range of genes encoding carbohydrate degradation/metabolism and oligosaccharide transport/assimilation in order to compete with B316Tfor the released sugars. These results suggest that B316Thas a role as an initiator of the primary solubilization of xylan and pectin, while MB2003 competes effectively as a scavenger for the released soluble sugars to enable its growth and maintenance in the rumen.IMPORTANCEFeeding a global population of nine billion people and climate change are the primary challenges facing agriculture today. Determining the roles of rumen microbes involved in plant polysaccharide breakdown is fundamental to understanding digestion and maximizing productivity of ruminant livestock.Butyrivibrioare abundant rumen bacteria and are a substantial source of polysaccharide-degrading enzymes with biotechnological applications for the depolymerization of lignocellulosic material. Our findings suggest that closely related species ofButyrivibriohave developed unique strategies for the degradation of plant fibre and the subsequent assimilation of carbohydrates in order to coexist in the competitive rumen environment. The identification of genes related to their enzymatic machinery by which these bacteria work in concert to degrade these different forms of polysaccharides contributes to our understanding of carbon flow in the rumen.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
José Francisco Cruz-Pérez ◽  
Roxana Lara-Oueilhe ◽  
Cynthia Marcos-Jiménez ◽  
Ricardo Cuatlayotl-Olarte ◽  
María Luisa Xiqui-Vázquez ◽  
...  

AbstractThe plant growth-promoting bacterium Azospirillum brasilense contains several genes encoding proteins involved in the biosynthesis and degradation of the second messenger cyclic-di-GMP, which may control key bacterial functions, such as biofilm formation and motility. Here, we analysed the function and expression of the cdgD gene, encoding a multidomain protein that includes GGDEF-EAL domains and CHASE and PAS domains. An insertional cdgD gene mutant was constructed, and analysis of biofilm and extracellular polymeric substance production, as well as the motility phenotype indicated that cdgD encoded a functional diguanylate protein. These results were correlated with a reduced overall cellular concentration of cyclic-di-GMP in the mutant over 48 h compared with that observed in the wild-type strain, which was recovered in the complemented strain. In addition, cdgD gene expression was measured in cells growing under planktonic or biofilm conditions, and differential expression was observed when KNO3 or NH4Cl was added to the minimal medium as a nitrogen source. The transcriptional fusion of the cdgD promoter with the gene encoding the autofluorescent mCherry protein indicated that the cdgD gene was expressed both under abiotic conditions and in association with wheat roots. Reduced colonization of wheat roots was observed for the mutant compared with the wild-type strain grown in the same soil conditions. The Azospirillum-plant association begins with the motility of the bacterium towards the plant rhizosphere followed by the adsorption and adherence of these bacteria to plant roots. Therefore, it is important to study the genes that contribute to this initial interaction of the bacterium with its host plant.


2010 ◽  
Vol 192 (24) ◽  
pp. 6492-6493 ◽  
Author(s):  
Angel Angelov ◽  
Susanne Liebl ◽  
Meike Ballschmiter ◽  
Mechthild Bömeke ◽  
Rüdiger Lehmann ◽  
...  

ABSTRACT Spirochaeta thermophila is a thermophilic, free-living anaerobe that is able to degrade various α- and β-linked sugar polymers, including cellulose. We report here the complete genome sequence of S. thermophila DSM 6192, which is the first genome sequence of a thermophilic, free-living member of the Spirochaetes phylum. The genome data reveal a high density of genes encoding enzymes from more than 30 glycoside hydrolase families, a noncellulosomal enzyme system for (hemi)cellulose degradation, and indicate the presence of a novel carbohydrate-binding module.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3924
Author(s):  
Maria Leonor Santos ◽  
Mariaelena D’Ambrosio ◽  
Ana P. Rodrigo ◽  
A. Jorge Parola ◽  
Pedro M. Costa

The past decade has seen growing interest in marine natural pigments for biotechnological applications. One of the most abundant classes of biological pigments is the tetrapyrroles, which are prized targets due their photodynamic properties; porphyrins are the best known examples of this group. Many animal porphyrinoids and other tetrapyrroles are produced through heme metabolic pathways, the best known of which are the bile pigments biliverdin and bilirubin. Eulalia is a marine Polychaeta characterized by its bright green coloration resulting from a remarkably wide range of greenish and yellowish tetrapyrroles, some of which have promising photodynamic properties. The present study combined metabolomics based on HPLC-DAD with RNA-seq transcriptomics to investigate the molecular pathways of porphyrinoid metabolism by comparing the worm’s proboscis and epidermis, which display distinct pigmentation patterns. The results showed that pigments are endogenous and seemingly heme-derived. The worm possesses homologs in both organs for genes encoding enzymes involved in heme metabolism such as ALAD, FECH, UROS, and PPOX. However, the findings also indicate that variants of the canonical enzymes of the heme biosynthesis pathway can be species- and organ-specific. These differences between molecular networks contribute to explain not only the differential pigmentation patterns between organs, but also the worm’s variety of novel endogenous tetrapyrrolic compounds.


2021 ◽  
Author(s):  
Jia-Wei Zhang ◽  
Hong-Po Dong ◽  
Li-Jun Hou ◽  
Yang Liu ◽  
Ya-Fei Ou ◽  
...  

AbstractAsgard archaea are widely distributed in anaerobic environments. Previous studies revealed the potential capability of Asgard archaea to utilize various organic substrates including proteins, carbohydrates, fatty acids, amino acids and hydrocarbons, suggesting that Asgard archaea play an important role in sediment carbon cycling. Here, we describe a previously unrecognized archaeal phylum, Hermodarchaeota, affiliated with the Asgard superphylum. The genomes of these archaea were recovered from metagenomes generated from mangrove sediments, and were found to encode alkyl/benzyl-succinate synthases and their activating enzymes that are similar to those identified in alkane-degrading sulfate-reducing bacteria. Hermodarchaeota also encode enzymes potentially involved in alkyl-coenzyme A and benzoyl-coenzyme A oxidation, the Wood–Ljungdahl pathway and nitrate reduction. These results indicate that members of this phylum have the potential to strictly anaerobically degrade alkanes and aromatic compounds, coupling the reduction of nitrate. By screening Sequence Read Archive, additional genes encoding 16S rRNA and alkyl/benzyl-succinate synthases analogous to those in Hermodarchaeota were identified in metagenomic datasets from a wide range of marine and freshwater sediments. These findings suggest that Asgard archaea capable of degrading alkanes and aromatics via formation of alkyl/benzyl-substituted succinates are ubiquitous in sediments.


2018 ◽  
Vol 7 (17) ◽  
Author(s):  
William G. Miller ◽  
Emma Yee

Arcobacter skirrowii is a species of veterinary importance, originally recovered from the feces, aborted fetuses, and preputial fluids of livestock. We present here the whole-genome sequence of the A. skirrowii type strain LMG 6621 (= 449/80T = CCUG 10374T), isolated in the United Kingdom from a lamb diarrheal fecal sample.


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