Metagenomic Analysis Of Bacterial Community Research Articles

Metagenomic Analysis of Bacterial Communities in Bee Bread in Türkiye

This study aims to investigate the bacterial community structure in bee bread samples collected from 10 provinces of Türkiye using next-generation sequencing (NGS) and metagenomic analysis. Bacterial genomic DNA was extracted and sequenced using Illumina MiSeq. Bioinformatic analysis involved quality assessment, OTU classification, principal coordinate analysis (PCoA), and diversity index calculations. Heatmap and PCoA were utilized to explore the impact of locality and ecological zones on microbial diversity. Metagenomic analysis of 12 bee bread samples revealed 276,583 high-quality sequencing reads. The dominant bacterial phyla identified were Proteobacteria, Actinobacteria, Cyanobacteria, and Firmicutes. At the genus level, Streptomyces, Streptococcus, Bacillus, and Synechococcus were the most abundant, with Streptomyces and Bacillus playing key roles in the fermentation process of bee bread. The Shannon diversity index (ranging from 2.92 to 4.26) and Simpson's index (0.83 to 0.95) indicated high species diversity and relative abundance in bee bread. The study underscores the need for locality-specific approaches in beekeeping management and highlights the potential significance of beneficial bacterial taxa, particularly those involved in fermentation, in contributing to the nutritional and health properties of bee bread. These findings provide a foundation for further research on the microbial dynamics that support bee colony health.

Behind the Scenes: Metagenomic Analysis of Bacterial Communities in Sustainable Depilation of Sheepskin.

The leather industry is embracing eco-friendly technologies for both regulatory compliance and sustainable growth. While enzymatic depilation provides a greener alternative to traditional beamhouse methods, its complexity often leads to higher costs. To address this, we examined the performance of sheepskins' native bacterial flora in acetic acid conditions with low environmental impact. Utilizing metagenomic techniques, we analyzed the bacterial community dynamics during the depilation process. This investigation revealed a notable increase in microbial diversity and richness in acetic acid treatments compared to water treatments. At the class level, a post-processing decrease in Gammaproteobacteria dominance was observed, while Actinomycetia numbers surged in the acetic acid group. In contrast, the water group showed an increase in Bacteroidia. Order-level analysis indicated reductions in Pseudomonadales and increases in Actinomycetales with acetic acid treatment, whereas Flavobacteriales was more prevalent in water-treated liquors. At the family level, Moraxellaceae decreased and Micrococcaceae increased in the acetic acid group, in contrast to the marked rise of Weeksellaceae in the water group. Temporal analyses further highlighted the evolving bacterial landscapes under different treatments. Moreover, acetic acid treatment fostered a stable microbial community, beneficial for sustainable leather processing. Functional pathways were predicted using PICRUSt2. It showed that significantly enriched degradation pathways in the water group were less abundant in the acetic acid group, potentially preventing substrate matrix damage during depilation. The study underscores the transformative potential of acetic acid for the leather industry, offering a pathway to reduce pollution while maintaining economic viability. By enhancing our understanding of microbial interactions during depilation, this study opens avenues for refining these eco-friendly techniques. Our findings advocate for a shift towards greener depilation methods and contribute to the broader dialogue on sustainable manufacturing practices, emphasizing the importance of leveraging indigenous microbial communities for environmental and economic gains.

Metagenomic analysis of bacterial communities in heavy metal leachate-contaminated soils at Jalan Lipis Sanitary Landfill, Pahang, Malaysia

A variety of bacterial communities can be found in heavy metal leachate-contaminated soil. These bacteria might have molecular defenses that allow them to endure a high heavy metal concentration. However, there aren't enough datasets on bacterial populations to be exploited for bioremediation, especially the biotreatment of leachate contaminated with heavy metals. This research examined the diversity of the bacterial population in heavy metal leachate-contaminated soil from the Jalan Lipis Sanitary Landfill in Pahang, Malaysia. The soil samples were taken from three (3) different locations. pH analysis showed that the heavy metal leachate-contaminated soil possesses alkaline pH. ICPMS analysis showed high concentration of nickel (112.96 mg/kg) followed by manganase (89.83 mg/kg), arsenic (43.84 mg/kg), and lead (3.62 mg/kg). The three most prevalent bacteria in the heavy metal leachate-contaminated soil from the site were Pseudomonas C (Proteobacteria), Flavobacterium (Bacteroidota), and Proteiniclasticum (Firmicutes), according to metagenomic sequencing of the 16 s rRNA gene. The alpha and beta bacterial diversity analysis indicate that each location with different heavy metal concentration differs significantly on its bacterial diversity providing a valuable information to be applied in heavy metal bioremediation exclusively from landfill leachate.

Effect of Biogenic Selenium Nanocomposite on Okra and Metagenomic Analysis of Bacterial Community Associated with Rhizosphere and Phyllosphere

Effect of Biogenic Selenium Nanocomposite on Okra and Metagenomic Analysis of Bacterial Community Associated with Rhizosphere and Phyllosphere

Metagenomic Analysis of Bacterial Community and Isolation of Representative Strains from Vranjska Banja Hot Spring, Serbia.

The hot spring Vranjska Banja is the hottest spring on the Balkan Peninsula with a water temperature of 63-95°C and a pH value of 7.1, in situ. According to the physicochemical analysis, Vranjska Banja hot spring belongs to the bicarbonated and sulfated hyperthermal waters. The structures of microbial community of this geothermal spring are still largely unexplored. In order to determine and monitor the diversity of microbiota of the Vranjska Banja hot spring, a comprehensive culture-independent metagenomic analysis was conducted in parallel with a culture-dependent approach for the first time. Microbial profiling using amplicon sequencing analysis revealed the presence of phylogenetically novel taxa, ranging from species to phyla. Cultivation-based methods resulted in the isolation of 17 strains belonging to the genera Anoxybacillus, Bacillus, Geobacillus, and Hydrogenophillus. Whole-genome sequencing of five representative strains was then performed. The genomic characterization and OrthoANI analysis revealed that the Vranjska Banja hot spring harbors phylogenetically novel species of the genus Anoxybacillus, proving its uniqueness. Moreover, these isolates contain stress response genes that enable them to survive in the harsh conditions of the hot springs. The results of the in silico analysis show that most of the sequenced strains have the potential to produce thermostable enzymes (proteases, lipases, amylases, phytase, chitinase, and glucanase) and various antimicrobial molecules that can be of great importance for industrial, agricultural, and biotechnological applications. Finally, this study provides a basis for further research and understanding of the metabolic potential of these microorganisms.

Metagenomic analysis of bacterial communities of Wadi Namar Lake, Riyadh, Saudi Arabia

Wadi Namar lake is a new touristic attraction area in the south of Riyadh. Human activities around the lake may lead to changes in water quality with subsequent changes in microenvironment components including microbial diversity. The current study was designed to assess possible changes in bacterial communities of the water at Wadi Namar Lake. Therefore, water samples were collected from three different locations along the lake: L1 (no human activities, no plants), L2 (no human activity, some plants) and L3 (human activities, municipal wastes and some plants). The total DNA of the samples was extracted and subjected to 16S rDNA sequencing and metagenomic analysis; water pH, electrical conductivity (EC), total dissolved solids (TDS) as well as the concentration of Na+1, K+1, Cl−1 and total N were analysed. Metagenomic analysis showed variations in relative abundance of 17 phyla, 31 families, 43 genera and 19 species of bacteria between the locations. Proteobacteria was the most abundant phylum in all locations; however, its highest abundance was in L1. Planctomycete phylum was highly abundant in L1 and L3, while its abundance in L2 was low. The phyla Acidobacteria, Candidatus Saccharibacteria, Nitrospirae and Chloroflexi were associated with high TDS, EC, K+1 and Cl−1 concentrations in L3; various human activities around this location had possibly affected microbial diversity. Current study results help in recognising the structure of bacterial communities at Wadi Namar Lake in relation to their surroundings for planning to environment protection and future restoration of affected ecosystems.

Metagenomic analysis of bacterial communities during estrous cycle in Bos indicus.

The present study, using 16s rRNA sequencing of the V3-V4 hypervariable region, was aimed to check diversity of vaginal microbiota throughout different stages of the estrous cycle in Bos indicus, with attention to changes in progesterone hormone and microorganism diversity. Metagenomic research was conducted on vaginal swabs obtained from nine healthy Indian Gir cows at estrus (day 0), metestrus (day 04), diestrus (day 12), and proestrus (day 16) phases of the estrous cycle. The findings revealed that the diestrus phase has a different bacterial diversity than the other three estrous cycle phases, implying that progesterone affects bacterial diversity. Proteobacteria and Firmicutes were the most abundant phyla at the phylum level, accounting for 94% of bacterial diversity. Actinobacteriota, Patescibacteria, Cyanobacteria, and Bacteroidota were among the less prevalent phyla observed in all samples. After statistical analysis, Bacillaceae, Alcaligenes, Enterobacteriaceae, and Morganellaceae families were more significant. The Enterobacteriaceae family was found to be lower in the diestrus phase than in the other three phases; in contrast, all statistically significant genera were high at the diestrus phase. The luteal stage had higher levels of Micrococcus, Stenotrophomonas, UGC-010, Massilia, and Methylobacillus than the follicular stage, and statistical analysis revealed substantial difference between the luteal and follicular stages. Lactobacillus genus was present in both the estrus and diestrus phases. This study represents an important step toward the understanding of microbial diversity within different stages of the estrous cycle of Indian cows.

Metagenomic Analysis of Bacterial Communities and Antibiotic Resistance Genes in Penaeus monodon Biofloc-Based Aquaculture Environments

Biofloc technology (BFT) is one of the most promising technologies in global aquaculture for the purpose of improving water quality, waste treatment, and disease prevention in intensive aquaculture systems. However, characterization of the microbial species and antibiotic resistance potentially present in biofloc-based aquaculture environments is needed. In this study, we used high-throughput sequencing technology to comprehensively compare the bacterial communities in mariculture ponds of Penaeus monodon (P. monodon), by testing of water, biofloc, and intestine of P. monodon. Operational taxonomic units (OTUs) cluster analysis showed that the nine samples tested divided into 45 phyla and 457 genera. Proteobacteria was the dominant bacteria in water, biofloc and prawn intestine. In biofloc and intestine, the Ruegeria (2.23–6.31%) genus represented the largest proportion of bacteria, with Marivita (14.01–20.94%) the largest group in water. Microbial functional annotation revealed that in all the samples, genes encoding metabolism were predominant. The antibiotic resistance gene annotation showed the highest absolute abundance of patB, adeF, OXA-243, and Brucella_suis_mprF from Proteobacteria. PatB (11.33–15.01%), adeF (15.79–18.16%), OXA-243 (35.65%), and Brucella_suis_mprF (10.03%) showed the highest absolute abundance of antibiotic resistance genes in water, biofloc, and intestines, respectively. These findings may greatly increase our understanding of the characteristics of the microbiota of shrimp biofloc-based aquaculture systems and the complex interactions among shrimp, ambient microflora, and environmental variables. It provides a reference basis for policy on breeding, environmental safety, and maintaining food safety in the production of P. monodon.

Metagenomic Analysis of Bacterial Communities in Agricultural Soils from Vietnam with Special Attention to Phosphate Solubilizing Bacteria.

Bacterial communities can promote increased phosphorus (P) availability for plants and microbes in soil via various mechanisms of phosphate solubilization. The production of extracellular phosphatases releases available P through the hydrolysis of organic P. Examining the abundance and diversity of the bacterial community, including phosphate solubilizing bacteria in soil, may provide valuable information to overcome P scarcity in soil ecosystems. Here, the diversity and relative abundance of bacterial phyla and genera of six agricultural soil samples from Vietnam were analysed by next generation sequencing of the 16S rRNA gene. Phosphatase activities of each soil were compared with physico-chemical parameters and the abundance of the alkaline phosphatase gene phoD. We showed the dominance of Chloroflexi, Proteobacteria, Actinobacteria, Acidobacteria and Firmicutes. Total nitrogen positively correlated with phyla Proteobacteria, Acidobacteria, Firmicutes and Planctomycetes. The abundance of several genera of Proteobacteria showed positive relationship with the copy number of the phoD gene. The abundance of several taxa positively correlated with silt content, while a negative relationship of Proteobacteria was found with sand content. Our results demonstrated the clear influence of soil physico-chemical properties on the abundance of various bacterial taxa including those potentially involved in phosphate solubilization.

16S rRNA gene amplicon-based metagenomic analysis of bacterial communities in the rhizospheres of selected mangrove species from Mida Creek and Gazi Bay, Kenya

Prokaryotic communities play key roles in biogeochemical transformation and cycling of nutrients in the productive mangrove ecosystem. In this study, the vertical distribution of rhizosphere bacteria was evaluated by profiling the bacterial diversity and community structure in the rhizospheres of four mangrove species (Sonneratia alba, Rhizophora mucronata, Ceriops tagal and Avicennia marina) from Mida Creek and Gazi Bay, Kenya, using DNA-metabarcoding. Alpha diversity was not significantly different between sites, but, significantly higher in the rhizospheres of S. alba and R. mucronata in Gazi Bay than in Mida Creek. Chemical parameters of the mangrove sediments significantly correlated inversely with alpha diversity metrics. The bacterial community structure was significantly differentiated by geographical location, mangrove species and sampling depth, however, differences in mangrove species and sediment chemical parameters explained more the variation in bacterial community structure. Proteobacteria (mainly Deltaproteobacteria and Gammaproteobacteria) was the dominant phylum while the families Desulfobacteraceae, Pirellulaceae and Syntrophobacteraceae were dominant in both study sites and across all mangrove species. Constrained redundancy analysis indicated that calcium, potassium, magnesium, electrical conductivity, pH, nitrogen, sodium, carbon and salinity contributed significantly to the species-environment relationship. Predicted functional profiling using PICRUSt2 revealed that pathways for sulfur and carbon metabolism were significantly enriched in Gazi Bay than Mida Creek. Overall, the results indicate that bacterial community composition and their potential function are influenced by mangrove species and a fluctuating influx of nutrients in the mangrove ecosystems of Gazi Bay and Mida Creek.

Metagenomic Analysis of Bacterial Communities in Water and Soil of the Fulani and non-Fulani in Nigeria.

Interactions between environmental factors (water and soil) and humans are inevitable, particularly in rural and semi-urbanized regions. As such, knowledge on the microbial constituents of these environmental factors is key to understanding potential risk to public health. However, the microbial profile of soil and water present in vulnerable human communities in Nigeria is currently unknown. This study sought to investigate the composition of soil and water microbiota in the environment inhabited by recently studied human communities (the Fulani nomadic group and the urbanized Jarawa ethnic group) and estimate the contribution of these environmental factors to the microbiome of the aforementioned human communities. Soil and water samples were collected from the Fulani and non-Fulani community in Jengre (Plateau State, Nigeria) and Jos (Plateau State, Nigeria), respectively. Genomic DNA was extracted from these environmental samples, followed by Illumina sequencing of the V4 region of the 16S rRNA gene and bioinformatics analysis via Quantitative Insights into Microbial Ecology QIIME. There is abundance of Proteobacteria (43%) signature members in soil samples obtained from both human communities. Analysis of the water samples revealed the abundance of Proteobacteria, particularly in water sourced from the borehole (Fulani). Pseudomonas (30%) had higher relative abundance in the drinking water of the Fulani. The drinking water of the Fulani could be a potential health risk to the studied Fulani community. Factors that increase the abundance of public health threats and health risk, such as hygiene practices, soil and water quality need to be studied further for the improvement of health in vulnerable populations.

Metagenomic Analysis of Bacterial Communities from a Nitrification–Denitrification Treatment of Landfill Leachates

AbstractThe efficiency of the biological removal of carbon and nitrogen from leachates is determined by the activity of microbial populations present in biological reactors. In this work, a complete characterization of bacterial communities revealed by personal genome machine sequencing (PGM) has been carried out from different points of a nitrification–denitrification process operated in an urban landfill. The leachate fed to the treatment is a mixture of young leachate, old leachate, and effluent from an anaerobic digestion process, in a volume ratio of 1:0.9:0.12, respectively. The anoxic and oxic reactors are followed by an ultrafiltration step. Samples are taken from different points of the process. Results reveal the microbial diversity of the samples, which include detection of minority populations that are difficult to explore by other methods. Bacteria belonging to Bacteroidetes and Proteobacteria are dominant in all the samples analyzed. Proteobacteria represents more than 50% of the total population in all cases. Samples taken after the biological treatment show a significant reduction in the relative abundance of Firmicutes, Tenericutes, and Lentisphaerae phyla in comparation with the initial leachate. The relative abundance of the classes is also studied and the most abundant in the samples are β‐Proteobacteria and Flavobacteria.

Metagenomic Analysis of Bacterial Communities Associated with Four Ecklonia cava Populations, Including Dokdo Island Population

The dynamics of the Ecklonia cava-associated microbiota in four Korean populations, Dokdo Island (DI), Ulleungdo Island (UI), Sangbaekdo Island (SI), and Seogwipo, were investigated to provide the initial data on E. cava-bacteria interactions in different localities. A pyrosequencing 454 analysis of the bacterial 16S rRNA genes was carried out, and the obtained sequences were analyzed by bioinformatic methods. The Chao 1 index showed that the bacterial community richness was highest in the Seogwipo population, which contained more highly abundant bacteria than the other populations according to the ACE index. The Shannon diversity index showed that the UI population was highly diverse. Bacteria of the phylum Proteobacteria were most abundant in all four populations (49–94%). Fifty-two genera were identified in the four E. cava populations. The microbiota at DI was dominated by Granulosicoccus (17.33%) and HQ845450_g (10.67%); HQ845450_g (11.67%) and Rhodobacteraceae_uc (7.50%) were abundant in the UI population; HQ845450_g (25.32%), Streptococcus (11.39%), and Desulfomonile (11.39%) were dominant in the SI population; and Vibrio (44.91%) and AM259833_f_uc (16.37%) were dominant in the Seogwipo population. The genus Granulosicoccus was found in all four groups. The microbiota in E. cava are largely dependent on the algal location, because only three bacterial operational taxonomic units (OTUs) were commonly found among the 850 bacterial sequences from four E. cava populations. The microbiota differences among the E. cava populations may contribute to seaweed forest conservation strategies at different locations.

Metagenomic analysis of bacterial communities and antibiotic resistance genes in the Eriocheir sinensis freshwater aquaculture environment

Aquaculture has attracted significant attention as an environmental gateway to the development of antibiotic resistance. The industry of Chinese mitten crab Eriocheir sinensis contributes significantly to the freshwater aquaculture industry in China. However, the situation of antibiotic resistance in the E. sinensis aquaculture environment is not known. In this study, high-throughput sequencing based metagenomic approaches were used to comprehensively investigate the structure of bacterial communities, the abundance and diversity of antibiotic resistance genes (ARGs), as well as mobile genetic elements (MGEs) in three E. sinensis aquaculture ponds in Jiangsu Province, China. The dominant phyla were Proteobacteria, Actinobacteria, and Bacteroidetes in water samples and Proteobacteria, Chloroflexi, Verrucomicrobia, and Bacteroidetes in sediment samples. Bacitracin and multidrug were predominant ARG types in water and sediment samples, respectively. There was a significant correlation between MGEs and ARGs. In particular, plasmids were the most abundant MGEs and strongly correlated with ARGs. This is the first study of antibiotic resistome that uses metagenomic approaches in the E. sinensis aquaculture environment. The results indicate that the opportunistic pathogens may acquire ARGs via horizontal gene transfer, intensifying the potential risk to human health.

Metagenomic analysis of bacterial community associated with postharvest Irvingia species fruit wastes

Metagenomic analysis of bacterial community associated with postharvest Irvingia species fruit wastes

BTEX removal in a modified free water surface wetland

A pilot scale free water surface (FWS) wetland with provision of additional intermediate berms composed of gravel material was tested for assessing its potential to remediate hydrocarbons present in produced water from a gas field. The average influent BTEX values were as follows: benzene (1.57mg/L), toluene (0.14mg/L), ethyl benzene (0.29mg/L), m and p-xylene (2.01mg/L) and o-xylene (0.13mg/L). The FWS wetland removed all monitored hydrocarbons with very good removal efficiencies during the monitoring period: benzene (92.6%), toluene (93.4%), ethyl benzene (98.3%), m and p-xylene (91.3%) and o-xylene (87.4%). Biodegradation was considered to be the main pathway for benzene removal in the studied system. Reaction kinetics were studied and the first-order area based rate coefficient for benzene was 0.13m/d while for BTEX it was 0.12m/d. Metagenomic analysis of bacterial community retrieved from the wetland showed majority of sequences were related to phylum proteobacteria.

Metagenomic Analysis of Bacterial Communities in the Rhizosphere of Leguminous Crops and Trees.

Legumes account for 27% of the world's primary crop production and contribute 33% to the dietary protein needs of humans. Important legume crops include clover, soybeans, alfalfa and peas. These plants are notable for their ability to form nitrogen‐fixing symbioses with bacteria of the genera rhizobia. These organisms live in the rhizosphere (the region of soil in the vicinity of plant roots) of legumes. Symbiotic nitrogen fixation in legume crops takes place in plant structures known as root nodules. Recent research suggests that certain tree species of the Leguminosae family do not form nodules but still possess nitrogen fixation capabilities (Bryan, 1996). The main objective of this study was to investigate the microbial communities associated with the rhizosphere of nodulating legume crops (alfalfa, clover and soybeans) and non‐nodulating leguminous trees (Honeylocust and Redbud). We hypothesized that examining the microbial communities in the rhizosphere of these plants will provide insights into the diversity of N2‐fixing microbes and the mechanisms of nitrogen fixation in non‐nodulating legumes. Total DNA was extracted from the rhizosphere and bacterial community analyzes were performed by sequencing the V4 region of the 16S rRNA gene. QIIME and UPARSE were used to analyze the sequencing reads and select operational taxonomic units (OTUs). A total of 441,587 qualified reads were obtained from the eight rhizosphere samples. Rarefaction curves obtained with the normalized OTUs number nearly reached saturation level for all the samples, indicating that bacterial communities from the rhizospheres were well covered by the sequence analysis. Phylogenetic analysis showed that Proteobacteria was the most abundant phylum in the rhizosphere of legumes covering 45–70% of the amplicons detected in the samples analyzed. Bacteriodes was the second major phylum followed by Acidobacteria and Actinobacteria. Regarding bacterial classes, the alphaproteobacteria and betaproteobacteria were abundant in crops while gammaproteobacteria and alphaproteobacteria were prevalent in leguminous trees. Principal component analysis indicated that bacterial communities could be separated into two groups according to their association with crops or trees. Rhizobium species were present in the rhizosphere of all the legumes analyzed. The presence of rhizobial species in the rhizosphere of non‐nodulating leguminous trees suggests that these microbes might have a role in the nitrogen fixation mechanisms utilized by these plants. This study provided valuable insights about the distribution of bacteria in the rhizosphere of agriculturally relevant leguminous crops and trees.

Clinical metagenomic analysis of bacterial communities in breast abscesses of granulomatous mastitis

Granulomatous mastitis (GM) is a chronic inflammatory breast lesion. Its etiology remains incompletely defined. Although mounting evidence suggests the involvement of Corynebacterium in GM, there has been no systematic study of GM bacteriology using -omics technology. The bacterial diversity and relative abundances in breast abscesses from 19 women with GM were investigated using 16S rDNA metagenomic sequencing and Sanger sequencing. A quantitative PCR (qPCR) assay was also developed to identify Corynebacterium kroppenstedtii. A bioinformatic analysis revealed that Corynebacterium was present in the 19 GM patients, with abundances ranging from 1.1% to 58.9%. Of note, Corynebacterium was the most abundant taxon in seven patients (more than a third of the subjects). The predominance of Corynebacterium kroppenstedtii infection (11 of 19 patients, 57.9%) was confirmed with Sanger sequencing and the qPCR assay. This study profiled the microbiota of patients with GM and indicated an important role for Corynebacterium, and in particular C. kroppenstedtii, in the pathogenesis of this disease.

Metagenomic Analysis of Bacterial Communities of Antarctic Surface Snow.

The diversity of bacteria present in surface snow around four Russian stations in Eastern Antarctica was studied by high throughput sequencing of amplified 16S rRNA gene fragments and shotgun metagenomic sequencing. Considerable class- and genus-level variation between the samples was revealed indicating a presence of inter-site diversity of bacteria in Antarctic snow. Flavobacterium was a major genus in one sampling site and was also detected in other sites. The diversity of flavobacterial type II-C CRISPR spacers in the samples was investigated by metagenome sequencing. Thousands of unique spacers were revealed with less than 35% overlap between the sampling sites, indicating an enormous natural variety of flavobacterial CRISPR spacers and, by extension, high level of adaptive activity of the corresponding CRISPR-Cas system. None of the spacers matched known spacers of flavobacterial isolates from the Northern hemisphere. Moreover, the percentage of spacers with matches with Antarctic metagenomic sequences obtained in this work was significantly higher than with sequences from much larger publically available environmental metagenomic database. The results indicate that despite the overall very high level of diversity, Antarctic Flavobacteria comprise a separate pool that experiences pressures from mobile genetic elements different from those present in other parts of the world. The results also establish analysis of metagenomic CRISPR spacer content as a powerful tool to study bacterial populations diversity.

Can microbes on skin help linking persons and crimes?

Linking persons to crimes through DNA analysis is a well-established approach for more than 25 years. While enormous numbers of cases all over the world have been solved based on DNA, there is still need for additional tools for improvement in physical evidence choice and collection. Unfortunately not all samples collected from crime scenes, are suitable for linking persons to crimes due to the quantity and quality of the human DNA collected. Recent studies have shown personality of bacterial community on human body surface that may open new perspectives for forensics. The aim of the study was evaluation of variability of bacterial communities on skin of palm and fingers between and within individuals as well as transfer of bacterial DNA during contact to the object and persistence of community parameters during storage. Four volunteers were recruited and samples collected during 5 days and afterwards once per week during 1 month in the morning and in the afternoon by swabbing of palm and fingers after holding sterile object for 1 min with persons dominant hand. The samples were also collected from the handled objects, except the first object, in which surface was quartered and sampled by quarter zone with 1-week interval after storing the object at room temperature. DNA was extracted and metagenomic analysis of bacterial community using 16S rRNA gene hypervariable regions was performed on Roche/454 platform. Our preliminary results are promising however foresee need for more elaborative studies to be able to implement this approach into the routine practice.