RESUMO
Sponge-associated prokaryotic diversity has been studied from a wide range of marine environments across the globe. However, for certain regions, e.g., Vietnam, Thailand, Cambodia, and Singapore, an overview of the sponge-associated prokaryotic communities is still pending. In this study we characterized the prokaryotic communities from 27 specimens, comprising 18 marine sponge species, sampled from the central coastal region of Vietnam. Illumina MiSeq sequencing of 16S ribosomal RNA (rRNA) gene fragments was used to investigate sponge-associated bacterial and archaeal diversity. Overall, 14 bacterial phyla and one archaeal phylum were identified among all 27 samples. The phylum Proteobacteria was present in all sponges and the most prevalent phylum in 15 out of 18 sponge species, albeit with pronounced differences at the class level. In contrast, Chloroflexi was the most abundant phylum in Halichondria sp., whereas Spirastrella sp. and Dactylospongia sp. were dominated by Actinobacteria. Several bacterial phyla such as Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Deferribacteres, Gemmatimonadetes, and Nitrospirae were found in two-thirds of the sponge species. Moreover, the phylum Thaumarchaeota (Archaea), which is known to comprise nitrifying archaea, was highly abundant among the majority of the 18 investigated sponge species. Altogether, this study demonstrates that the diversity of prokaryotic communities associated with Vietnamese sponges is comparable to sponge-prokaryotic assemblages from well-documented regions. Furthermore, the phylogenetically divergent sponges hosted species-specific prokaryotic communities, thus demonstrating the influence of host identity on the composition and diversity of the associated communities. Therefore, this high-throughput 16S rRNA gene amplicon analysis of Vietnamese sponge-prokaryotic communities provides a foundation for future studies on sponge symbiont function and sponge-derived bioactive compounds from this region.
RESUMO
A real-time reverse transcription-polymerase chain reaction (qRT-PCR) assay was developed for the fast and highly sensitive detection of the sacbrood virus (SBV) genome and applied to honeybee samples. Using plasmid DNA containing a partial SBV genome and diluted serially, as few as 1×10(2)copies/µl (correlation co-efficiency >0.99) were detected by the qRT-PCR assay, whereas 1×10(3)copies/µl were detected by the conventional RT-PCR assay. As a rapid detection method, ultra-rapid real-time PCR (URRT-PCR) was carried out with a GenSpector TMC-1000 silicon-glass chip-based thermal cycler, which has a 6µl micro-chamber volume and a fast outstandingly heating/cooling rate. Using this method, 10(3)copies of pBX-SBV3.8 clone were detected within 17 min after 40 PCR cycles, including melting point analysis. To reduce the detection time for SBV, synthesis of the cDNA of the SBV genome from a honeybee sample was attempted for different reaction times and the cDNA was used as the template for URRT-PCR assays. The results indicated that a 5 min reaction time was sufficient to synthesize cDNA as the template for the SBV URRT-PCR assay. This study described a novel PCR-based method that is able to detect an RNA virus in environmental samples within 22 min, including reverse transcription, PCR detection and melting point analysis in real-time.
