The metagenomics analysis of air, dust and surfaces of tropical buildings

This study focuses on systematic comparisons between 3 types of samples (dust, air, surface) commonly analyzed in environmental quality studies for better understanding on the source-sink relationships among microbial communities found in different samples. Dust, air and surface swab samples were collected from an indoor and its nearby outdoor locations. DNA was then extracted from the samples and direct (shotgun) metagenomic sequencing approach was applied for microbial community profiling of the samples. The current results indicate a moderate to high correlation between the surface and the settling dust samples.MOE (Min. of Education, S’pore)Accepted versio

Whole-genome sequencing of Aspergillus terreus species complex

Aspergillus terreus species complex is an opportunistic fungal pathogen increasingly implicated in invasive infection, as well as chronic respiratory disease. Currently, an understanding of A. terreus pathogenicity is impeded by a limited number of whole-genome sequences of this fungal pathogen. We here describe a high-quality whole-genome assembly of European A. terreus clinical isolate M6925, derived by single-molecule real-time sequencing with short-read polishing

Taxonomic composition and seasonal dynamics of the air microbiome in West Siberia

Here, we describe taxonomical composition, as well as seasonal and diel dynamics of airborne microbial communities in West Siberia. A total of 78 airborne biomass samples from 39 time intervals were analysed, within a temperature range of 48 °C (26 °C to - 22 °C). We observed a 5-170-fold decrease in DNA yield extracted from the airborne biomass in winter compared to summer, nevertheless, yielding sufficient material for metagenomic analysis. The airborne microbial communities included Actinobacteria and Proteobacteria, Ascomycota and Basidiomycota fungi as major components, as well as some Streptophyta plants. In summer, bacterial and fungal plant pathogens, and wood-rotting saprophytes were predominant. In winter, Ascomycota moulds and cold-related or stress environment bacterial species were enriched, while the fraction of wood-rotting and mushroom-forming Basidiomycota fungi was largely reduced. As recently reported for the tropical climate, the airborne microbial communities performed a diel cycle in summer, however, in winter diel dynamics were not observed.Ministry of Education (MOE)Published versionThis study was supported by Academic Research Fund (AcRF) Tier 3, Singapore Ministry of Education (grant number: MOE2013-T3-1-013). V.N.K and V.A.S were supported by the Russian Foundation of Basic Research (Project #18-29-13045). We thank Dr. Sharon Longford, Senior Assistant Director, Science Communications, Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University for critical reading of this manuscript

Complete genome sequence of Curtobacterium sp. strain SGAir0471, isolated from Singapore air samples

Curtobacterium sp. strain SGAir0471 was isolated from tropical air samples collected in Singapore. The genome was assembled using PacBio RS II long reads and Illumina MiSeq short paired-end reads. The complete genome measures 3.53 Mb and consists of 3,151 protein-coding genes, 49 tRNAs, and 12 rRNAs.MOE (Min. of Education, S’pore)Published versio

Complete genome sequence of Nissabacter sp. strain SGAir0207, isolated from an air sample collected in Singapore

Nissabacter sp. strain SGAir0207 was isolated from a tropical air sample collected in Singapore. Its genome was assembled using a hybrid approach with long and short reads, resulting in one chromosome of 3.9 Mb and 7 plasmids. The complete genome consists of 4,403 protein-coding, 84 tRNA, and 22 rRNA genes.MOE (Min. of Education, S’pore)Published versio

Genome sequence of the tropical atmosphere bacterium Pontibacter sp. strain SGAir0037

The Pontibacter bacterial genus has been detected in marine and soil environments. Here, we report the genome sequence of Pontibacter sp. strain SGAir0037, which was isolated from outdoor air samples collected in Singapore. The genome comprises one chromosome of 5.26 Mb and one plasmid of 127 kb.MOE (Min. of Education, S’pore)Published versio

Complete genome sequence of the bacterium Serratia marcescens SGAir0764, isolated from Singapore air

Serratia marcescens strain SGAir0764 was isolated from a tropical air sample collected in Singapore. The complete genome, sequenced on the PacBio RS II platform, consists of one chromosome with 5.1 Mb and one plasmid with 76.4 kb. Genome annotation predicts 4,723 protein-coding genes, 89 tRNAs, and 22 rRNAs.MOE (Min. of Education, S’pore)Published versio

Complete genome sequence of Brachybacterium sp. strain SGAir0954, isolated from Singapore air

Brachybacterium sp. strain SGAir0954 was isolated from tropical air collected in Singapore, and its genome was sequenced and assembled using long reads generated by single-molecule real-time (SMRT) sequencing. The complete genome has a size of 3.41 Mb and consists of 2,955 protein coding genes, 50 tRNAs, and 9 rRNAs.MOE (Min. of Education, S’pore)Published versio

Genome sequence of Geobacillus thermoleovorans SGAir0734, isolated from Singapore air

The thermophilic bacterium Geobacillus thermoleovorans was isolated from a tropical air sample collected in Singapore. The genome was sequenced on the PacBio RS II platform and consists of one chromosome with 3.6 Mb and one plasmid with 75 kb. The genome comprises 3,509 protein-coding genes, 88 tRNAs, and 27 rRNAs.MOE (Min. of Education, S’pore)Published versio

Experimental parameters defining ultra-low biomass bioaerosol analysis

Investigation of the microbial ecology of terrestrial, aquatic and atmospheric ecosystems requires specific sampling and analytical technologies, owing to vastly different biomass densities typically encountered. In particular, the ultra-low biomass nature of air presents an inherent analytical challenge that is confounded by temporal fluctuations in community structure. Our ultra-low biomass pipeline advances the field of bioaerosol research by significantly reducing sampling times from days/weeks/months to minutes/hours, while maintaining the ability to perform species-level identification through direct metagenomic sequencing. The study further addresses all experimental factors contributing to analysis outcome, such as amassment, storage and extraction, as well as factors that impact on nucleic acid analysis. Quantity and quality of nucleic acid extracts from each optimisation step are evaluated using fluorometry, qPCR and sequencing. Both metagenomics and marker gene amplification-based (16S and ITS) sequencing are assessed with regard to their taxonomic resolution and inter-comparability. The pipeline is robust across a wide range of climatic settings, ranging from arctic to desert to tropical environments. Ultimately, the pipeline can be adapted to environmental settings, such as dust and surfaces, which also require ultra-low biomass analytics.Ministry of Education (MOE)Published versionThe work was supported by Singapore Ministry of Education Academic Research Fund Tier 3 grant (grant MOE2013-T3-1-013)