We examined the abundance, diversity and community composition of airborne fungi in swine houses during winter and summer seasons by using quantitative PCR and Illumina HiSeq sequencing of ITS1 region. The abundance of airborne fungi varied significantly only between seasons, while fungal diversity varied significantly both within and between seasons, with both abundance and diversity peaked in winter. The fungal OTU composition was largely structured by the swine house unit and season as well as by their interactions. Of the measured microclimate variables, relative humidity, particulate matters (PMs), ammonia, and stocking density were significantly correlated with fungal OTU composition. The variation in beta diversity was higher within swine houses during summer, which indicates that the airborne fungal community composition was more heterogeneous in summer compared to winter. We also identified several potential allergen/pathogen related fungal genera in swine houses. The total relative abundance of potential allergen/pathogen related fungal genera varied between swine houses in both seasons, and showed positive correlation with PM2.5. Overall, our findings show that the abundance, diversity and composition of airborne fungi are highly variable in swine houses and to a large extent structured by indoor microclimate variables of swine houses.
The influence of climate change on microbial communities inhabiting the sparsely vegetated patterned ground soils that are widespread across the High Arctic is poorly understood. Here, in a four-year experiment on Svalbard, we warmed patterned ground soil with open top chambers and biannually irrigated the soil to predict the responses of its microbial community to rising temperatures and precipitation. A 1 °C rise in summertime soil temperature caused 44% and 78% increases in CO2 efflux and CH4 consumption, respectively, and a 32% increase in the frequency of bacterial 16S ribosomal RNA genes. Bacterial alpha diversity was unaffected by the treatments, but, of the 40 most frequent bacterial taxa, warming caused 44–45% reductions in the relative abundances of a Sphingomonas sp. and Ferruginibacter sp. and 33–91% increases in those of a Phenylobacterium sp. and a member of the Acetobacteraceae. Warming did not influence the frequency of fungal internal transcribed spacer 2 copies, and irrigation had no effects on the measured variables. Our study suggests rapid changes to the activities and abundances of microbes, and particularly bacteria, in High Arctic patterned ground soils as they warm. At current rates of soil warming on Svalbard (0.8 °C per decade), we anticipate that similar effects to those reported here will manifest themselves in the natural environment by approximately the mid 2030s.
7 March 2015 in Journal of Animal Science and Technology
A simple binary scoring system (SBSS) was developed and used to assess the welfare measures of commercial broiler chickens in South Korea. We also correlated welfare measures with environmental parameters of broiler house. Our measures of welfare included lameness, hock burn (HB) and foot pad dermatitis (FPD), whilst environmental parameters included air temperature, relative humidity, air speed, light intensity, air quality (in particular carbon dioxide (CO2) and ammonia (NH3) concentrations) and airborne microbes. The effect of environmental parameters on welfare measures was apparent even on 10-day-old broilers. A non-parametric correlation analysis revealed significant correlations between environmental parameters and welfare measures. The key environmental parameters were relative humidity and light intensity. The results indicate that there is a need for proper control of environmental conditions on poultry farms, which could reduce health problems and subsequently reduce disease and mortality. In conclusion, the simplicity of SBSS makes it preferable over more complex scoring systems and allows a farmer to more easily assess the welfare measures on their own farm.
The ecological processes underlying the observed patterns in community composition of archaea in swine manure slurry are poorly understood. We studied the archaeal communities from six swine manure slurry storage tanks using paired-end Illumina sequencing of the v3 hypervariable region of 16S rRNA gene. Across all samples, the archaeal community was dominated by methanogens related to Thermoplasmata, Methanomicrobia , and Methanobacteria classes. At the genus level, the archaeal community was dominated by a single uncultured lineage of archaea, vadinCA11 , followed by methanogenic genera Methanobrevibacter , Methanosarcina , Methanosphaera , Methanogenium , Methanocorpusculum , Methanoculleus , and Methanomicrococcus . Significant phylogenetic signals were detected across relatively short phylogenetic distances, indicating that closely related archaeal operational taxonomic units (OTUs) tend to have similar niches. The standardized effect sizes of mean nearest taxon distance (SES.MNTD) showed that archaeal community was phylogenetically clustered, suggesting that environmental filtering deterministically influence the within-community composition of archaea. However, between-community analysis based on β -nearest taxon index ( β NTI) revealed that both deterministic selection and stochastic processes operate simultaneously to govern the assembly of archaeal communities. These findings significantly enhance our understanding of archaeal community assembly and underlying ecological processes is swine manure slurry.
Long-term irrigation of agricultural fields with distillery effluent (DE) may alter the physical, chemical and biological properties of the soil. Microorganisms are critical to the maintenance of soil health and productivity. However, the impact of DE irrigation on activity and taxonomy of soil microorganisms is poorly understood. Here we studied plant-growth-promoting (PGP) traits and taxonomic composition of bacterial communities in agricultural soil irrigated with DE in conjugation with irrigation water, using cultivation-dependent and - independent methods. Most of the bacterial isolates obtained from DE irrigated soil were found to display PGP traits (phosphate solubilization, siderophore, indolic compounds and ammonia production). Diverse bacterial taxa were found in both culturable bacterial community and 16S rRNA gene clone library, which belonged to bacterial phylaProteobacteria(Alpha-, Beta- and Gamma- subdivisions),Firmicutes, Actinobacteria, Acidobacteria, BacteroidetesandGemmatimonadates. Overall, these results indicate that PGP traits and taxonomic diversity of soil bacterial communities were not severely impacted by DE irrigation.