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PubMed2026

Pilot metaproteomic profiling reveals bacterial diversity and potential medical and veterinary relevance of tick microbiomes in northern Algeria.

Ticks are major ectoparasites and vectors of pathogens affecting humans, livestock, and wildlife. They harbor diverse microbial communities that may influence tick biology and interactions with microorganisms; however, functional information on tick-associated microbiomes remains limited, particularly in North Africa. In this pilot study, we applied a metaproteomic approach based on high-resolution tandem mass spectrometry to characterize bacterial communities associated with three tick species collected in Algeria: Rhipicephalus sanguineus sensu lato, Hyalomma aegyptium, and Hyalomma dromedarii. Peptide spectra were assigned to taxa using a two-step database search strategy based on NCBInr, and bacterial composition and relative abundance were compared across tick species and sampling locations. A total of 40 bacterial genera belonging to 32 families and four phyla were identified. Microbiome composition differed significantly between tick genera and collection locations, suggesting an influence of species-specific and geographical factors on microbial community structure. Dominant genera included Streptomyces, Bacillus, Clostridium, Escherichia, Flavobacterium, Paenibacillus, and Providencia. Peptides related to Coxiella spp. were frequently detected, consistent with previous reports of Coxiella-like endosymbionts in ticks. This pilot study provides a first metaproteomic characterization of tick-associated communities in Algeria. The results reveal species- and location-associated differences in microbial composition and highlight the potential of metaproteomics for exploring tick-associated microbiomes in North Africa.

Animals↗

PubMed2005

Analysis of cyanobacterial pigments and proteins by electrophoretic and chromatographic methods.

Cyanobacteria are a diverse and ubiquitous group of prokaryotes with several unifying features. Amongst these is the macromolecular structure known as the phycobilisome, which is composed of water-soluble phycobiliproteins covalently bound by linker peptides or proteins in a configuration designed to optimize energy transfer to the photosynthetic reaction center of the organism. Phycobiliproteins are highly fluorescent by virtue of their covalently bound, linear tetrapyrrole chromophores known as bilins. Analysis of these prosthetic pigments, along with other non-water soluble pigments, such as the chlorophylls and carotenoids, can provide insight into microbial diversity. The effects of environmental growth conditions and stresses can also be probed by measuring pigment and protein concentrations. This review will focus, therefore, on applications of various chromatographic and electrophoretic methods for the analysis of cyanobacterial pigment and protein constituents. Although the greatest emphasis will be placed on the measurement of bilins and phycobiliproteins, this review will also consider other pigments and proteins important to cyanobacterial growth and survival, such as chlorophyll a, carotenoids, ectoenzymes, linker and membrane proteins, and extracellular proteins.

Chromatography↗

PubMed2004

Sulfate-reducing bacteria-dominated biofilms that precipitate ZnS in a subsurface circumneutral-pH mine drainage system.

The microbial diversity of ZnS-forming biofilms in 8 degrees C, circumneutral-pH groundwater in tunnels within the abandoned Piquette Zn, Pb mine (Tennyson, Wisconsin, USA) has been investigated by molecular methods, fluorescence in situ hybridization (FISH), and cultivation techniques. These biofilms are growing on old mine timbers that generate locally anaerobic zones within the mine drainage system. Sulfate-reducing bacteria (SRB) exclusively of the family Desulfobacteriaceae comprise a significant fraction of the active microbiota. Desulfosporosinus strains were isolated, but could not be detected by molecular methods. Other important microbial clusters belonged to the beta-, gamma-, and epsilon-Proteobacteria, the Cytophaga/Flexibacter/Bacteroides-group (CFB), Planctomycetales, Spirochaetales, Clostridia, and green nonsulfur bacteria. Our investigations indicated a growth dependence of SRB on fermentative, cellulolytic, and organic acid-producing Clostridia. A few clones related to sulfur-oxidizing bacteria were detected, suggesting a sulfur cycle related to redox gradients within the biofilm. Sulfur oxidation prevents sulfide accumulation that would lead to precipitation of other sulfide phases. FISH analyses indicated that Desulfobacteriaceae populations were not early colonizers in freshly grown and ZnS-poor biofilms, whereas they were abundant in older, naturally established, and ZnS-rich biofilms. Gram-negative SRB have been detected in situ over a period of 6 months, supporting the important role of these organisms in selective ZnS precipitation in Tennyson mine. Results demonstrate the complex nature of biofilms responsible for in situ bioremediation of toxic metals in a subsurface mine drainage system.

Bacteria↗

PubMed2026

Bridging the airway microbiome and targeted therapy in bronchiectasis: multi-omics insights, endotypes and emerging therapies.

Bronchiectasis is a heterogeneous chronic airway disease primarily driven by persistent infection, microbial dysbiosis and dysregulated host immunity. While culture-based microbiology has historically informed clinical management, advances in high-throughput sequencing and multi-omic technologies have transformed our understanding of the airway ecosystem, revealing that disease activity is shaped not only by individual pathogens, but by complex and dynamic host-microbe interactions. Despite the breadth of descriptive microbiome data, translation into clinically actionable diagnostics or therapies has been limited. Importantly, cross-sectional correlations between microbiota and inflammation do not establish cause and effect, underscoring the need to embed host-microbiome profiling within both longitudinal and interventional therapeutic trials. In this review, we critically appraise current microbial and host multi-omics research in bronchiectasis, integrating microbiome studies with host inflammatory, proteomic and immunophenotyping data. We highlight themes emerging across cohorts, including low microbial diversity, pathogen dominance, loss of commensal networks and neutrophil-driven inflammation, and discuss how these features align with biological endotypes associated with exacerbations and treatment response. Drawing on lessons from host-directed therapeutic successes, we examine translational roadblocks limiting microbiome-guided care. We further review emerging microbiome-modulating strategies such as pathogen-specific biologics, bacteriophage therapy, live biotherapeutic products, biofilm-targeting adjuncts and precision antibiotic stewardship. Finally, we propose a roadmap toward microbiome-informed precision medicine through harmonised methodologies, integration of host and microbial biomarkers into clinical trials, and embedding multi-omics pipelines within large international registries. Collectively, these advances have the potential to shift bronchiectasis research and clinical management towards rationally designed, precision medicine-driven therapeutic strategies.

Humans↗

PubMed2005

Introducing DOTUR, a computer program for defining operational taxonomic units and estimating species richness.

Although copious qualitative information describes the members of the diverse microbial communities on Earth, statistical approaches for quantifying and comparing the numbers and compositions of lineages in communities are lacking. We present a method that addresses the challenge of assigning sequences to operational taxonomic units (OTUs) based on the genetic distances between sequences. We developed a computer program, DOTUR, which assigns sequences to OTUs by using either the furthest, average, or nearest neighbor algorithm for each distance level. DOTUR uses the frequency at which each OTU is observed to construct rarefaction and collector's curves for various measures of richness and diversity. We analyzed 16S rRNA gene libraries derived from Scottish and Amazonian soils and the Sargasso Sea with DOTUR, which assigned sequences to OTUs rapidly and reliably based on the genetic distances between sequences and identified previous inconsistencies and errors in assigning sequences to OTUs. An analysis of the two 16S rRNA gene libraries from soil demonstrated that they do not contain enough sequences to support a claim that they contain different numbers of bacterial lineages with statistical confidence (P > 0.05), nor do they contain enough sequences to provide a robust estimate of species richness when an OTU is defined as containing sequences that are no more than 3% different from each other. In contrast, the richness of OTUs at the 3% level in the Sargasso Sea collection began to plateau after the sampling of 690 sequences. We anticipate that an equivalent extent of sampling for soil would require sampling more than 10,000 sequences, almost 100 times the size of typical sequence collections obtained from soil.

Algorithms↗

PubMed1999

The effect of a model melanoidin mixture on faecal bacterial populations in vitro.

The Maillard reaction produces coloured, macromolecular materials (melanoidins) in a variety of foods, on heating. Significant quantities may enter the human gut on a daily basis, but there is little information on their metabolism in the human colon. As the large bowel contains a diverse population of bacteria involved in normal bowel function, it is possible that melanoidins are metabolized therein. Depending on the bacteria involved, there may be disease or health implications. The aim of the present study was to use in vitro models to determine the digestibility of melanoidins and the effect of melanoidins on colonic bacteria in the gastrointestinal tract. Melanoidins were prepared and the effects of simulated upper-gut secretions on their stability determined in a model system. The effects of faecal bacteria were also determined, in batch culture, with a combination of phenotypic and genotypic (probes) criteria being used to identify the microbial diversity involved. Simulation of peptic and pancreatic digestion showed that the melanoidins did not produce detectable amounts of low-molecular-mass degradation products. However, melanoidins affected the growth of gut bacteria during mixed culture growth. The effect was to cause a non-specific increase in the anaerobic bacteria enumerated. This in vitro study indicates that melanoidins can affect the growth of human large-bowel bacteria and serves to demonstrate possible effects that may occur in vivo. Given the large and varied number of food items that contain Maillard reaction products, this may have relevance for lower-gut health.

Adult↗

PubMed2005

Occurrence and diversity of yeasts in the mid-atlantic ridge hydrothermal fields near the Azores Archipelago.

The yeast community associated with deep-sea hydrothermal systems of the Mid-Atlantic Rift was surveyed for the first time. This study relied on a culture-based approach using two different growth media: a conventional culture medium for yeasts supplemented with sea salts (MYPss) and the same medium additionally supplemented with sulfur (MYPssS). For the evaluation of species diversity, a molecular approach involving minisatellite-primed polymerase chain reaction (MSP-PCR) strain typing and sequence analysis of the D1/D2 domains of the 26S rDNA was followed. In the seven water samples that were studied, the number of colony-forming units per liter (cfu/L) ranged from 0 to 5940. The nonpigmented yeasts were much more abundant than the pink-pigmented ones. This disproportion was not observed in studies of other marine systems and may be due to the unique conditions of hydrothermal vents, characterized by a rich animal and microbial diversity and therefore by the availability of organic compounds utilizable by yeasts. Higher counts of nonpigmented yeast were obtained using MYPss, whereas for pink yeasts, higher counts were obtained using MYPssS. Moreover, among pink yeasts, some of the MSP-PCR classes obtained were composed of isolates obtained only on MYPssS, which might be an indication that these isolates are adapted to the ecosystems of the hydrothermal vents. Twelve phylotypes belonged to the Ascomycota and seven phylotypes belonged to the Basidiomycota. The nonpigmented yeasts were identified as Candida atlantica, C. atmosphaerica, C. lodderae, C. parapsilosis, Exophiala dermatitidis, Pichia guilliermondii, and Trichosporon dermatis, whereas the pigmented yeasts were identified as Rhodosporidium diobovatum, R. sphaerocarpum, R. toruloides, and Rhodotorula mucilaginosa. Some of the yeasts that were found belong to phylogenetic groups that include species reported from other marine environments, and eight phylotypes represent undescribed species. The new phylotypes found at Mid-Atlantic Ridge hydrothermal fields represent 33% of the total number of yeast taxa that were found.

Azores↗

PubMed2004

Use of RAPD-PCR and TTGE for the evaluation of biodiversity of whey cultures for Grana Padano cheese.

AIMS: This work was carried out in order to evaluate the microbial diversity of whey cultures collected from different Grana Padano cheese plants in Veneto region (north-east Italy) by means of RAPD-PCR and Temporal Temperature Gradient Gel Electrophoresis (TTGE) analysis. METHODS AND RESULTS: Lactobacillus helveticus was the dominant species among isolated thermophilic lactobacilli. RAPD-PCR with primers M13 and D8635 resulted a suitable method for typing Lact. helveticus at strain level. Thirteen different Lact. helveticus biotypes were detected in the seven whey cultures studied with one biotype present in all the whey cultures. Besides Lact. helveticus, Lact. delbrueckii subsp. lactis was the main microbial species detected by TTGE. CONCLUSIONS: RAPD-PCR resulted very useful in studying Lact. helveticus biodiversity; furthermore, TTGE analysis allowed to detect the dominant thermophilic microflora characteristic of Grana Padano cheese whey cultures. IMPACT OF THE STUDY: By the combined used of RAPD-PCR and TTGE it could be possible to follow the behaviour in strain or species composition of whey cultures during time.

Bacterial Typing Techniques↗

PubMed2005

Design, development, and use of molecular primers and probes for the detection of Gluconacetobacter species in the pink sugarcane mealybug.

Molecular tools for the species-specific detection of Gluconacetobacter sacchari, Gluconacetobacter diazotrophicus, and Gluconacetobacter liquefaciens from the pink sugarcane mealybug (PSMB) Saccharicoccus sacchari Cockerell (Homiptera: Pseudococcidae) were developed and used in polymerase chain reactions (PCR) and in fluorescence in situ hybridizations (FISH) to better understand the microbial diversity and the numerical significance of the acetic acid bacteria in the PSMB microenvironment. The presence of these species in the PSMB occurred over a wide range of sites, but not in all sites in sugarcane-growing areas of Queensland, Australia, and was variable over time. Molecular probes for use in FISH were also designed for the three acetic acid bacterial species, and shown to be specific only for the target species. Use of these probes in FISH of "squashed" whole mealybugs indicated that these acetic acid bacteria species represent only a small proportion of the microbial population of the PSMB. Despite the detection of Glac. sacchari, Glac. diazotrophicus, and Glac. liquefaciens by PCR from different mealybugs isolated at various times and from various sugarcane-growing areas in Queensland, Australia, these bacteria do not appear to be significant commensals in the PSMB environment.

Animals↗

PubMed2007

Continuous enrichment culturing of thermophiles under sulfate and nitrate-reducing conditions and at deep-sea hydrostatic pressures.

A continuous culture bioreactor was developed to enrich for nitrate and sulfate reducing thermophiles under in situ deep-sea pressures. The ultimate objective of this experimental design was to be able to study microbial activities at chemical and physical conditions relevant to seafloor hydrothermal vents. Sulfide, sulfate and oxide minerals from sampled seafloor vent-chimney structures [East Pacific Rise (9 degrees 46'N)] served as source mineral and microbial inoculum for enrichment culturing using nitrate and sulfate-enriched media at 70 and 90 degrees C and 250 bars. Changes in microbial diversity during the continuous reaction flow were monitored using denaturing gradient gel electrophoresis (DGGE) of PCR amplified 16S rRNA gene fragments. Time series changes in fluid chemistry were also monitored throughout the experiment to assess the feedback between mineral-fluid reaction and metabolic processes. Data indicate a shift from the dominance of epsilon Proteobacteria in the initial inoculum to the several Aquificales-like phylotypes in nitrate-reducing enrichment media and Thermodesulfobacteriales in the sulfate-reducing enrichment media. Methanogens were detected in the original sulfide sample and grew in selected sulfate-enriched experiments. Microbial interactions with anhydrite and pyrrhotite in the chimney material resulted in measurable changes in fluid chemistry despite a fluid residence time only 75 min in the reactor. Changes in temperature rather than source material resulted in greater differences in microbial enrichments and mediated geochemical reactions.

Biodiversity↗

PubMed2026

Supplementation with effective microorganisms in earthen ponds affects common carp growth and abundance of specific bacterial families.

BACKGROUND: Effective microorganisms are increasingly explored in aquaculture to improve fish health and growth without leaving harmful residues. However, their efficacy in real-world pond environments remains poorly understood. Here, we conducted a 103-day field experiment to assess the effects of supplementation with two effective commercial microorganism products on the microbial communities and growth performance of common carp (Cyprinus carpio). BACKGROUND: Effective microorganisms were added to the feed and directly to the pond water. Microbial diversity was analysed via 16 S rRNA and whole-genome shotgun sequencing across three environments: water (three time points), sediment (two time points), and fish intestine (one time point) from 25 experimental ponds. Bioinformatics processing was performed using the QIIME2 and MG-TK pipelines with taxonomic classification based on the SILVA database. The results showed that although supplemented bacterial families did not establish significantly in pond environments, fish exposed to specific effective microorganism treatments showed improved growth metrics. CONCLUSIONS: These findings suggest that effective microorganisms can increase carp growth in aquaculture without significantly altering the resident microbial communities, suggesting a promising residue-free alternative to traditional additives in aquaculture.

Animals↗

PubMed2003

Analysis of environmental microbial communities by reverse sample genome probing.

Development of fast and accurate methods for monitoring environmental microbial diversity is one of the great challenges in microbiology today. Oligonucleotide probes based on 16S rRNA sequences are widely used to identify bacteria in the environment. However, the successful development of a chip of immobilized 16S rRNA probes for identification of large numbers of species in a single hybridization step has not yet been reported. In reverse sample genome probing (RSGP), labelled total community DNA is hybridized to arrays in which genomes of cultured microorganisms are spotted on a solid support in denatured form. This method has provided useful information on changes in composition of the cultured component of microbial communities in oil fields, the soil rhizhosphere, hydrocarbon-contaminated soils and acid mine drainage sites. Applications and limitations of the method, as well as the prospects of extending RSGP to cover also the as yet uncultured component of microbial communities, are evaluated.

Bacteria↗

PubMed2004

Description of heterotrophic bacteria occurring in paper mills and paper products.

AIMS: To isolate aerobic mesophilic bacilli and thermophilic bacteria from different paper mill samples and to evaluate their potential harmfulness. METHODS AND RESULTS: A total of 109 mesophilic and 68 thermophilic isolates were purified and characterized by automated ribotyping and partial 16S rDNA sequencing. The mesophilic isolates belonged to the genera Bacillus (13 taxa), Brevibacillus (three taxa) and Paenibacillus (five taxa). The thermophilic bacteria represented seven taxa of Bacillus, Geobacillus or Paenibacillus, four of proteobacteria and one of actinobacteria. The most frequently occurring bacteria were Bacillus cereus, B. licheniformis, Pseudoxanthomonas taiwanensis and bacteria closely related to Paenibacillus stellifer, P. turicensis or Leptothrix sp. One mill was contaminated throughout with bacteria of a novel mesophilic genus most closely related to Brevibacillus centrosporus and another with bacteria of a novel thermophilic genus most closely related to Hydrogenophilus thermoluteolus. One B. cereus isolate producing haemolytic diarrhoeal enterotoxin was detected and all the tested B. licheniformis isolates produced a metabolite toxic to boar sperm cells. CONCLUSIONS: The bacilli and thermophilic bacteria isolated represent species which should not present occupational hazards in paper mill environments. The most harmful bacterium detected was B. licheniformis and potentially also B. cereus. SIGNIFICANCE AND IMPACT OF THE STUDY: Knowledge of the microbial diversity in a paper mill provides a rational basis for development of an effective controlling programme. A database constructed from the fingerprints generated using automated ribotyping helps to identify and trace the contamination routes of bacteria occurring in paper mills.

Bacillus↗

PubMed1997

Enhancement of resolution of low molecular weight RNA profiles by staircase electrophoresis.

Stable low molecular weight (LMW) RNA comprises molecules used in the taxonomy of microorganisms and in studies on the microbial diversity of populations. However, the use of electrophoretic techniques has been hampered due to the low resolution obtained with techniques used for the separation of this kind of molecule. In this work we develop an electrophoretic method (staircase electrophoresis) that increases the resolution of the technique. This improvement in the resolution adequately resolves the three zones that integrate the profiles of LMW RNA: ribosomic 5S RNA (5S rRNA), class 2 transfer RNA (tRNA), and class 1 transfer RNA, allowing the technique to be applied to taxonomic studies (diagnostic, the identification of the individuals), phylogenetic studies and studies on naturally occurring microbial populations.

Electrophoresis↗

PubMed2007

Influence of anode pretreatment on its microbial colonization.

AIMS: To assess the influence of chemical treatment of the anode of a marine sediment biofuel cell (MSBFC) on the microbial diversity of the anode biofilm. METHODS AND RESULTS: A MSBFC was equipped with two graphite plate anodes, one pretreated by electrochemical oxidation in sulfuric acid and the other untreated. After 6 weeks of operation, 16S rRNA clone libraries were constructed from each anode biofilm. The pretreated anode exhibited a fourfold depletion in gamma-proteobacteria, a fourfold enrichment in delta-proteobacteria, a sixfold increase in sulfate reducers, a fivefold enrichment in unclassified micro-organisms, and 6% of the colonies were sulfur oxidizers while none were detected on the untreated anode. CONCLUSION: Anode pretreatment significantly affects the anode-colonized microbial communities of MSBFCs. SIGNIFICANCE AND IMPACT OF THE STUDY: The MSBFC is one of a new class of microbial fuel cells in which the anode is spontaneously colonized by a subset of micro-organisms indigenous to a complex anaerobic mixture (such as sewage and food processing effluents). These micro-organisms utilize the anode as an oxidant, catalysing power generation by oxidizing fuel in the mixture and reducing the anode. This study reveals that pretreatment of the anode can greatly affect the composition of the microbial colony of such fuel cells.

Alphaproteobacteria↗

PubMed2003

Formation of pseudo-terminal restriction fragments, a PCR-related bias affecting terminal restriction fragment length polymorphism analysis of microbial community structure.

Terminal restriction fragment length polymorphism (T-RFLP) analysis of PCR-amplified genes is a widely used fingerprinting technique in molecular microbial ecology. In this study, we show that besides expected terminal restriction fragments (T-RFs), additional secondary T-RFs occur in T-RFLP analysis of amplicons from cloned 16S rRNA genes at high frequency. A total of 50% of 109 bacterial and 78% of 68 archaeal clones from the guts of cetoniid beetle larvae, using MspI and AluI as restriction enzymes, respectively, were affected by the presence of these additional T-RFs. These peaks were called "pseudo-T-RFs" since they can be detected as terminal fluorescently labeled fragments in T-RFLP analysis but do not represent the primary terminal restriction site as indicated by sequence data analysis. Pseudo-T-RFs were also identified in T-RFLP profiles of pure culture and environmental DNA extracts. Digestion of amplicons with the single-strand-specific mung bean nuclease prior to T-RFLP analysis completely eliminated pseudo-T-RFs. This clearly indicates that single-stranded amplicons are the reason for the formation of pseudo-T-RFs, most probably because single-stranded restriction sites cannot be cleaved by restriction enzymes. The strong dependence of pseudo-T-RF formation on the number of cycles used in PCR indicates that (partly) single-stranded amplicons can be formed during amplification of 16S rRNA genes. In a model, we explain how transiently formed secondary structures of single-stranded amplicons may render single-stranded amplicons accessible to restriction enzymes. The occurrence of pseudo-T-RFs has consequences for the interpretation of T-RFLP profiles from environmental samples, since pseudo-T-RFs may lead to an overestimation of microbial diversity. Therefore, it is advisable to establish 16S rRNA gene sequence clone libraries in parallel with T-RFLP analysis from the same sample and to check clones for their in vitro digestion T-RF pattern to facilitate the detection of pseudo-T-RFs.

Animals↗

PubMed2026

Metagenomic insights into the global wild boar faecal microbiome reveal novel taxa and carbohydrate degraders distinguishing wild and domesticated Sus.

BACKGROUND: The inclusion of fibre in domestic pig diets is favourable from a digestive health, environmental, and socio-economic perspective. Unlike the highly optimized formulated diets of domestic pigs, wild boars feed opportunistically, consuming a broad range of foods that consist predominantly of plant materials. Consequently, the intestinal microbiota of wild boars is thought to be adapted to a versatile, fibre-rich diet and may represent a valuable source of probiotics for enhancing fibre degradation. However, comprehensive studies characterizing the wild boar gut microbiome, particularly its community structure and carbohydrate utilization potential, and comparison to that of domestic pigs are still lacking. RESULTS: We collected 89 faecal samples from wild boars across four countries and analysed them primarily using metagenomic sequencing. De novo assembly yielded 3,288 high- and medium-quality metagenome-assembled genomes (MAGs) representing 968 distinct species, of which 538 were previously unknown. Incorporating these MAGs enabled robust microbiome comparisons with 125 previously published samples largely from domestic pigs, which revealed significant structural and functional differences. These differences resolved into two community types, determined not by host species but by diet and lifestyle: C1 comprising 81% of samples from free-ranging, foraging wild boars and C2 consisting of 93% of samples from captive, fed domestic pigs. The lower alpha-diversity observed in C1 likely reflected the impact of highly fluctuating dietary resources and environmental conditions, resulting in dominance of fewer resilient or adaptable taxa. Nevertheless, both community types maintained substantial carbohydrate utilization potential: while C2 exhibited a higher relative abundance of CAZymesub genes associated with a broader range of carbohydrate substrate (CHO) classes, C1 was enriched in individual species that were generally richer in CAZymesub genes and CHO classes. To leverage this potential, we curated a catalogue of carbohydrate degraders from both community types and identified 47 highly versatile species, with several novel species amongst them. CONCLUSIONS: This study uncovered the previously untapped microbial diversity in the wild boar faecal microbiome and demonstrated that the faecal microbiome of Sus is primarily shaped by diet and lifestyle. The two community types identified, which differed both structurally and functionally, represent alternative states of microbiome homeostasis in wild versus domesticated Sus populations. The curated catalogue of carbohydrate degraders provides a valuable resource to guide tailored probiotic supplementation during dietary transitions to novel fibrous feedstocks. Video Abstract.

Animals↗

PubMed2006

Molecular detection and diversity of medium-chain-length polyhydroxyalkanoates-producing bacteria enriched from activated sludge.

AIMS: Knowledge of the species composition of complex bacterial communities is still very limited. The main objectives of this study were to identify medium-chain-length polyhydroxyalkanoates (mcl-PHAs)-producing bacteria from activated sludge fed with methanol as well as to characterize their PHA operon. METHODS AND RESULTS: The identification was based on PCR amplification of mcl-PHA synthase gene fragments. In the analysed sample, four isolates possessing mcl-PHA synthesis systems were distinguished. The results of a 16S rDNA sequence analysis revealed that three strains belonged to Pseudomonas species and the fourth one was characterized as Comamonas testosteroni. CONCLUSIONS: The results of this study indicate that the PCR-RFLP approach is an excellent way to identify mcl-PHA-synthesizing micro-organisms. The discovery of 4 genetic variants, among the 20 analysed, demonstrates that microbial diversity of activated sludge is high and thus offers a great opportunity for the discovery of novel gene forms. SIGNIFICANCE AND IMPACT OF THE STUDY: An important discovery of this study is that C. testosteroni could harbour mcl-PHA operon. Moreover, the results obtained indicate that PHAs synthesis ability can be spread by horizontal gene transfer. The results of a comparative phylogenetic analysis revealed that mcl-PHA-synthesizing bacteria can be divided into Pseudomonas fluorescens and Pseudomonas aeruginosa groups.

Acyltransferases↗