https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47961 Mon 22 Apr 2024 14:49:14 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46262 Symbiodinium tridacnidorum and Durusdinium trenchii) using gas chromatography–mass spectrometry (GC–MS) and comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC x GC–TOFMS). Seven chemical classes were detected by both instruments, the most common being aromatic hydrocarbons. However, GC x GC resolved seven times more BVOCs than GC–MS (290 vs. 40), with a higher proportion of compounds tentatively identified (173 vs. 14). Notably, nine chemical classes were exclusively identified by GC x GC, including alkane, alkene, aldehyde, ester, and nitrile BVOCs—each potentially fulfilling undescribed functions in marine organisms. The microalgal species investigated shared a large proportion of BVOCs, and this result was consistent across instruments (97 and 98% shared compounds via GC x GC and GC–MS, respectively), suggesting consistent retrieval of general patterns between instruments. This method comparison is the first of its kind in marine systems and confirms the greater analytical power of GC x GC, required to help resolve complex BVOC emissions and the identification of their roles in marine systems.]]> Mon 14 Nov 2022 15:58:32 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39867 Arcobacter in clinical settings grows, the ecological dynamics of potentially pathogenic Arcobacter in coastal marine environments remains unclear. In this study, we monitored the temporal dynamics of Arcobacter at an urban beach subject to significant stormwater input and wet weather sewer overflows (WWSO). Weekly monitoring of bacterial communities over 24 months using 16S rRNA amplicon sequencing revealed large, intermittent peaks in the relative abundance of Arcobacter. Quantitative PCR was subsequently employed to track absolute abundance of Arcobacter 23S rRNA gene copies, revealing peaks in abundance reaching up to 10⁸ gene copies L⁻¹, with these increases statistically correlated with stormwater and WWSO intrusion. Notably, peaks in Arcobacter abundance were poorly correlated with enterococci plate counts, and remained elevated for one week following heavy rainfall. Using oligotyping we discriminated single nucleotide variants (SNVs) within the Arcobacter population, revealing 10 distinct clusters of SNVs that we defined as Arcobacter “ecotypes”, with each displaying distinct temporal dynamics. The most abundant ecotype during stormwater and modelled WWSO events displayed 16S rRNA sequence similarity to A. cryaerophilius, a species previously implicated in human illness. Our findings highlight the diverse environmental drivers of Arcobacter abundance within coastal settings and point to a potentially important, yet overlooked exposure risk of these potential pathogens to humans.]]> Fri 15 Jul 2022 10:37:34 AEST ]]>