Deciphering microbial communities and their unique metabolic repertoire across rock-soil-plant continuum in the Dayoukeng fumarolic geothermal field of the Tatun Volcano Group.

High temperature and sulfur concentrations in geothermal sulfur fumaroles host unique microbial ecosystems with niche-specific metabolic diversity and physiological functions. In this study, the microbial communities and their functionalities associated with the Dayoukeng geothermal field and the rock-soil-plant continuum were investigated to underpin the microbial modulation at different distances from the fumaroles source. At the phylum level, Bacteroidota, Planctomycetota, Armatimonadota, and Patescibacteria were abundant in plant samples; Elusimicrobiota and Desulfobacterota were in the rock samples while Nitrospirota, Micrarchaeota, and Deinococcota were dominant in the soil samples. Acidophilic thermophiles were enriched in samples within close proximity to the fumaroles, primarily at a distance of 1 m. The sulfur and iron-oxidizing acidophilic bacterial genera such as Acidothiobacillus and Sulfobacillus were abundant in the rock samples. The thermoacidophilic archaeon Acidianus and acidophilic bacteria Acidiphilium were abundant in the soil samples. Additionally, Thermosporothrix and Acidothermus were found abundant in the plant samples. The results of the functional annotation indicated that dark sulfur oxidation, iron oxidation, and hydrogen oxidation pathways were abundant in the soil samples up to 1 m from the fumaroles, while methanogenic and fermentation pathways were more prevalent in the soil samples located 10 m from the fumaroles. Interestingly, the results of this study indicated a higher microbial richness and abundance of acidophilic communities in the soils and plants compared to the rocks of the DYK fumarolic geothermal field.

Systematic assessment of mineral distribution and diversity of microbial communities and its interactions in the Taiwan subduction zone of mud volcanoes.

Mud volcanoes are the most dynamic and unstable sedimentary structures in the areas of tectonic compression like the subduction zones. In this study, we comprehensively analyzed the distribution of minerals as well as diversity, abundance and metabolic potential of the microbial communities of major mud volcanic groups across Taiwan namely Chu-kou Fault (CKF), Gu-ting-keng Anticline (GTKA), Chi-shan Fault (CSF), and Longitudinal Valley Fault (LVF). The mud volcano fluids recorded relatively higher Na and Cl contents than the other elements, particularly in the CKF and GTKA groups. The highest microbial diversity and richness were observed in the CSF group, followed by the GTKA group, whereas the lowest microbial diversity was observed in the CKF and LVF groups. Proteobacteria were common in all the sampling sites, except WST-7 and WST-H (Wu-Shan-Ting) of the CSF group, which were abundant in Chloroflexi. The halophilic genus Alterococcus was abundant in the Na-and Cl-rich CL-A sites of the CKF group. Sulfurovum was dominant in the CLHS (Chung-Lun hot spring) site of the CKF group and was positively correlated with sulfur/thiosulfate respiration, which might have resulted in a higher expression of these pathways in the respective group. Aerobic methane-oxidizing microbial communities, such as Methylobacter, Methylomicrobium, Methylomonas, and Methylosoma, constituted a dominant part of the LVF and CSF groups, except for the YNH-A and YNH-B (Yang-Nyu-Hu) sites. The WST-7 and JS sites were abundant in both methane-producing and methane-oxidizing microbial communities. The LGH-F1 (Lei-Gong-Huo) site was dominated by both methanotrophic and methylotrophic genera, such as Methylomicrobium and Methylophaga, respectively. Methylotrophy, methanotrophs, and hydrocarbon-degrading pathways were more abundant in the LVF and CSF groups but not in the remaining groups. The results of this study extend our knowledge of the diversity, abundance, and metabolic functions of prokaryotes in major terrestrial mud volcanoes in Taiwan.

Analysis and interpretation of hot springs water, biofilms, and sediment bacterial community profiling and their metabolic potential in the area of Taiwan geothermal ecosystem.

Microorganisms developed a mechanism that copes with heat, acidity, and high dissolved metal concentrations that likely first evolved. The geothermal fluids emerging in the geothermal springs of Taiwan, located at a subduction zone, are still under signs of progress in the characterization of the various microbial taxonomic changes over time. However, no systematic studies have been performed to compare water, biofilms, and sediment bacterial communities and the primary driving force of dissolved and mineral substrates capable of supporting microbial metabolism. In this study, 16S rRNA gene sequencing was employed for bacterial community exploration, and their potential metabolic pathways involved from water, biofilms, and sediment samples, collected from the geothermal valley (Ti-re-ku). Metagenomic data revealed that the water samples had higher bacterial diversity and richness than biofilms and sediment samples. At the genus level, Alicyclobacillus, Thiomonas, Acidocella, Metallibacterium, Picrophilus, and Legionella were significantly abundant in the water samples. The biofilms were rich in Aciditerrimonas, Bacillus, Acidithiobacillus, and Lysinibacillus, whereas the sediment samples were abundant in Sulfobacillus. The PICRUSt2-predicted functional results revealed that heavy metal-related functions such as heavy-metal exporter system, cobalt­zinc­cadmium resistance, arsenical pump, high-affinity nickel-transport, and copper resistance metabolisms were significant in the water samples. Moreover, sulfur-related pathways such as thiosulfate oxidation, dissimilatory sulfate reduction, and assimilatory sulfate reduction were important in water samples, followed by biofilms and sediment. Therefore, our findings highlighted the comparative taxonomic diversity and functional composition contributions to geothermal fluid, with implications for understanding the evolution and ecological niche dimension of microbes which are the key to geothermal ecosystem function.

Adenovirus in fishery harbours and identification of contamination sources.

Adenoviruses (AdVs) are a major cause of clinical infections and have been proposed as indicators of water quality. However, quantitative data on the environmental prevalence of AdVs is lacking. We investigated the prevalence, distribution, seasonal occurrence, quantity, and genotype of AdVs in 13 fishing harbours in Taiwan. AdVs in the water samples were isolated by membrane filtration and the AdV DNA was extracted. Next, AdVs were detected using nested polymerase chain reaction. Genotyping and phylogenetic analysis were performed to identify various AdV genotypes present in the water samples. The F species human AdV (HAdV) serotype 41 (63.6%) and C species porcine AdV (PAdV) serotype 5 (33.3%) were more prevalent than the other serotypes. The prevalence of AdVs was highest in the fall, followed by in the spring and summer. Among the fishing harbours, the highest detection rate of AdVs was observed in Yenpudongang in all seasons. However, Puoziliao was the only site at which AdVs were not detected during the study period. AdV detection at sampling sites may be correlated with sewage and livestock wastewater discharge via outflow of nearby rivers to fishing ports. Statistical analysis (Mann-Whitney U test) based on data from water quality indicators revealed that the presence of AdVs was significantly associated with the heterotrophic plate count, pH, and salinity. Human and swine population data from nearby local townships and river/drainage basins were collected from the Taiwan Central Government's website. The data were analyzed using Spearman's rank correlation coefficient to determine the relationship between the prevalence of AdVs, HAdVs, and PAdVs in fishing harbours, and microbial water quality indicators. Statistical evidence indicated that the detection levels of HAdVs and PAdVs in fishing harbours were mainly associated with human and swine populations in the corresponding river/drainage basin, respectively. Additionally, the swine population in the river/drainage basin was positively correlated with microbial water quality indicators.

Comprehensive assessment of bacterial communities and their functional profiles in the Huang Gang Creek in the Tatun Volcano Group basin, Taiwan using 16S rRNA amplicon sequencing.

The microbial characteristics of water bodies located in the outflow of hot springs may affect the water quality parameters of the associated river ecosystem. Using 16S rRNA amplicon sequencing, we investigated the bacterial diversity and functional profiles of the Huang Gang (HG) Creek, located in the trace metal-rich, acid-sulfate thermal springs zone of the Tatun Volcano Group (TVG). Biofilms and water samples were collected from the upstream, midstream, and geothermal valleys and downstream of the creek. The results showed that the biofilm and water samples had distinct bacterial diversity and abundance profiles. Acidophilic sulfur-oxidizing bacteria were found to be more abundant in water samples, whereas aquatic photosynthetic bacterial communities were dominant in biofilms. The water samples were contaminated with Legionella and Chlamydiae, which could contaminate the nearby river and cause clinical infections in humans. The upstream samples were highly unique and displayed higher diversity than the other sites. Moderate thermo-acidophiles were dominant in the upstream and midstream regions, whereas the geothermal valley and downstream samples were abundant in thermo-acidophiles. In addition, functional profiling revealed higher expression of sulfur, arsenic, and iron-related functions in water and lead-related functions in the biofilms of the creek. As described in previous studies, the hydrochemical properties of the HG Creek were influenced by the TVG hot springs. Our findings indicated that the hydrochemical properties of the HG Creek were highly correlated with the bacterial diversity and functional potential of running water as compared to biofilms.

Comparison of bacterial communities and their functional profiling using 16S rRNA gene sequencing between the inherent serpentine-associated sites, hyper-accumulator, downgradient agricultural farmlands, and distal non-serpentine soils.

This study aims to determine and compare the bacterial community and functional profiles associated with serpentine sites, innate hyper-accumulating weed, downgradient agricultural farmlands and non-serpentine sites using 16S rRNA gene sequencing. Elemental analysis revealed that the serpentine rock and weathered soil have higher magnesium, nickel, chromium, magnesium/calcium and lower calcium/magnesium ratios and agricultural farmlands have recorded elevated chromium. Proteobacteria were found predominant, except the non-serpentine site which was rich in Cyanobacteria. PCA analysis at the genus level indicates the uniqueness of different experimental groups, except the hyperaccumulators which exhibited relatively less dissimilarity. The shift analysis showed the serpentine sites were characterized by the abundance of bacteria having heavy metal effluxion. The hyper-accumulating weeds were higher in plant growth-promoting bacteria expressing tolerance against heavy metals toxicity such as nickel, chromium, cobalt and arsenic. Besides, the agricultural lands were abundant in wetland-associated methanogens and metal (manganese, iron and zinc) transporting function related bacteria. The results suggest that the inherent edaphic factors including heavy metal content, the interacting behavior of hyperaccumulator's rhizosphere microbiota with soil and anthropogenic activities such as agricultural practices could be a major determinant of the variation in the bacterial community selection and abundance in the respective study sites.

Surveillance of Adenovirus and Norovirus Contaminants in the Water and Shellfish of Major Oyster Breeding Farms and Fishing Ports in Taiwan.

The enteric viruses, including adenovirus (AdVs) and norovirus (NoVs), in shellfish is a significant food safety risk. This study investigated the prevalence, seasonal occurrence, genetic diversity, and quantification of AdVs and NoVs in the water and cultured shellfish samples at the four major coastal oyster breeding farms (COBF), five major fishing ports (FP), and their markets in Taiwan. The AdVs/NoVs in the water and shellfish samples were isolated by the membrane filtration and direct elution methods. The RNA of NoVs was reverse-transcribed into complementary DNA through reverse transcription reaction. Further NoVs and AdVs were detected using nested PCR. A higher detection rate was recorded in the low-temperature period than high-temperature. Detection difference was noted between nested PCR and qPCR outcomes for AdVs. The total detection rate of AdVs was higher in the water samples (COBF-40.6%, FP 20%) than the shellfish samples (COBF-11.7% and FP 6.3%). The AdVs load in the water and shellfish samples ranged from 1.23 × 103 to 1.00 × 106 copies/L and 3.57 × 103 to 4.27 × 104 copies/100g, respectively. The total detection of NoVs was highest in the water samples of the FP and their market shellfish samples (11.1% and 3.2%, respectively). Genotyping and phylogenetic analysis were identified as the prevalent AdVs and NoVs genotypes in the water and shellfish samples: A species HAdVs serotype 12; F species HAdVs serotype 41; and C species PAdVs serotype 5 (NoVs GI.2, GI.3 and GII.2). No significant differences were observed between the presence of AdVs, and all of the water quality parameters evaluated (heterotrophic plate count, water temperature, turbidity, pH, salinity, and dissolved oxygen). The virus contamination occurs mainly due to the direct discharge of domestic sewage, livestock farm, and fishing market wastewater into the coastal environment. Thus, this study suggested framing better estuarine management to prevent AdVs/NoVs transmission in water and cultured/distributed shellfish.

The Evaluation of Bacterial Abundance and Functional Potentials in the Three Major Watersheds, Located in the Hot Spring Zone of the Tatun Volcano Group Basin, Taiwan.

The Tatun Volcanic Group (TVG), located in northern Taiwan, is characterized by acidic hot springs where the outflow of the hot springs may affect the properties of the associated lotic water bodies. We investigated the bacterial diversity and functional profiles of the Peihuang (PHC), HuangGang (HGC), and Nanhuang Creeks (NHC) located in the TVG basin using 16S rRNA gene sequencing coupled with statistical analyses. Water samples were collected from various streams of the creeks for two months of the year. The NHC showed the highest diversity, richness, and a unique number of phyla, which was followed by the HGC. A reduced number of phyla and a lower diversity was noticed in the PHC. The NHC was found to be abundant in the genera Armatimonas, Prosthecobacter, Pirellula, and Bdellovibrio, whereas the HGC was rich in Thiomonas, Acidiphilium, Prevotella, Acidocella, Acidithiobacillus, and Metallibacterium. The PHC was abundant in Thiomonsa, Legionella, Acidocella, and Sulfuriferula. The samples did not show any strong seasonal variations with the bacterial diversity and abundance; however, the relative abundance of each sampling site varied within the sampling months. The iron transport protein- and the sulfur metabolism-related pathways were predicted to be the key functions in all the creeks, whereas the heavy metal-related functions, such as the cobalt/nickel transport protein and the cobalt-zinc-cadmium efflux system were found to be abundant in the HGC and PHC, respectively. The abundance of Bdellovibrio in the NHC, Diplorickettsia in the HGC, and Legionella in the PHC samples indicated a higher anthropogenic impact over the creek water quality. This study provides the data to understand the distinct bacterial community structure, as well as the functional potentials of the three major watersheds, and helps the knowledge of the impact of the physicochemical properties of the TVG hot springs upon the watersheds.

Role of Bioaerosols on the Short-Distance Transmission of Multidrug-Resistant Methicillin-Resistant Staphylococcus aureus (MRSA) in a Chicken Farm Environment.

Methicillin-resistant Staphylococcus aureus (MRSA) is a dynamic and tenacious pathogenic bacterium which is prevalent in livestock farming environments. This study investigated the possibility of MRSA spread via bioaerosol transmission from an indoor chicken farm environment to outdoors downwind (up to 50 m). The concentration of total airborne bacteria colony formation units (CFUs) was decreased with increasing sampling distance ranging from 9.18 × 101 to 3.67 × 103 per air volume (m3). Among the 21 MRSA isolates, 15 were isolated from indoor chicken sheds and exposure square areas, whereas 6 were isolated from downwind bioaerosol samples. Molecular characterization revealed that all of them carried the staphylococcal cassette chromosome mec (SCCmec) VIII, and they were remarkably linked with the hospital-associated MRSA group. Spa typing analysis determined that all MRSA isolates belonged to spa type t002. Virulence analysis showed that 100% of total isolates possessed exfoliative toxin A (eta), whereas 38.09% and 23.80% strains carried exfoliative toxin B (etb) and enterotoxin A (entA). Additionally, all of these MRSA isolates carried multidrug resistance properties and showed their resistance against chloramphenicol, ciprofloxacin, clindamycin, tetracycline, and erythromycin. In addition, chi-squared statistical analysis displayed a significant distributional relationship of gene phenotypes between MRSA isolates from chicken farm indoor and downwind bioaerosol samples. The results of this study revealed that chicken farm indoor air might act as a hotspot of MRSA local community-level outbreak, wherein the short-distance dispersal of MRSA could be supported by bioaerosols.

Assessment of Temporal Effects of a Mud Volcanic Eruption on the Bacterial Community and Their Predicted Metabolic Functions in the Mud Volcanic Sites of Niaosong, Southern Taiwan.

The microbial communities inhabiting mud volcanoes have received more attention due to their noteworthy impact on the global methane cycle. However, the impact of temporal effects of volcanic eruptions on the microbial community's diversity and functions remain poorly characterized. This study aimed to underpin the temporal variations in the bacterial community's diversity and PICRUSt-predicted functional profile changes of mud volcanic sites located in southern Taiwan using 16S rRNA gene sequencing. The physicochemical analysis showed that the samples were slightly alkaline and had elevated levels of Na+, Cl-, and SO42-. Comparatively, the major and trace element contents were distinctly higher, and tended to be increased in the long-period samples. Alpha diversity metrics revealed that the bacterial diversity and abundance were lesser in the initial period, but increased over time. Instead, day 96 and 418 samples showed reduced bacterial abundance, which may have been due to the dry spell that occurred before each sampling. The initial-period samples were significantly abundant in haloalkaliphilic marine-inhabiting, hydrocarbon-degrading bacterial genera such as Marinobacter, Halomonas, Marinobacterium, and Oceanimonas. Sulfur-reducing bacteria such as Desulfurispirillum and Desulfofarcimen were found dominant in the mid-period samples, whereas the methanogenic archaeon Methanosarcina was abundant in the long-period samples. Unfortunately, heavy precipitation encountered during the mid and long periods may have polluted the volcanic site with animal pathogens such as Desulfofarcimen and Erysipelothrix. The functional prediction results showed that lipid biosynthesis and ubiquinol pathways were significantly abundant in the initial days, and the super pathway of glucose and xylose degradation was rich in the long-period samples. The findings of this study highlighted that the temporal effects of a mud volcanic eruption highly influenced the bacterial diversity, abundance, and functional profiles in our study site.

Assessment of Carbon Substrate Catabolism Pattern and Functional Metabolic Pathway for Microbiota of Limestone Caves.

Carbon utilization of bacterial communities is a key factor of the biomineralization process in limestone-rich curst areas. An efficient carbon catabolism of the microbial community is associated with the availability of carbon sources in such an ecological niche. As cave environments promote oligotrophic (carbon source stress) situations, the present study investigated the variations of different carbon substrate utilization patterns of soil and rock microbial communities between outside and inside cave environments in limestone-rich crust topography by Biolog EcoPlate™ assay and categorized their taxonomical structure and predicted functional metabolic pathways based on 16S rRNA amplicon sequencing. Community level physiological profiling (CLPP) analysis by Biolog EcoPlate™ assay revealed that microbes from outside of the cave were metabolically active and had higher carbon source utilization rate than the microbial community inside the cave. 16S rRNA amplicon sequence analysis demonstrated, among eight predominant bacterial phylum Planctomycetes, Proteobacteria, Cyanobacteria, and Nitrospirae were predominantly associated with outside-cave samples, whereas Acidobacteria, Actinobacteria, Chloroflexi, and Gemmatimonadetes were associated with inside-cave samples. Functional prediction showed bacterial communities both inside and outside of the cave were functionally involved in the metabolism of carbohydrates, amino acids, lipids, xenobiotic compounds, energy metabolism, and environmental information processing. However, the amino acid and carbohydrate metabolic pathways were predominantly linked to the outside-cave samples, while xenobiotic compounds, lipids, other amino acids, and energy metabolism were associated with inside-cave samples. Overall, a positive correlation was observed between Biolog EcoPlate™ assay carbon utilization and the abundance of functional metabolic pathways in this study.

Prevalence, Distribution, and Genotypes of Adenovirus and Norovirus in the Puzi River and Its Tributaries and the Surrounding Areas in Taiwan.

This study investigated the prevalence, distribution, and genotypes of adenoviruses (AdVs) and noroviruses (NoVs) in the Puzi River and surrounding areas in Taiwan. The viruses in the water samples were isolated using the membrane filtration method and the viral nucleic acids were extracted. The RNA of NoVs was reverse-transcribed into complementary DNA using reverse transcriptase-polymerase chain reaction. AdVs and NoVs were detected using nested PCR. Genotyping and phylogenetic analyses were performed to identify the various viral genotypes in the water samples. Human adenovirus (HAdVs) and porcine adenovirus (PAdVs) were the predominant genotypes in the water samples. The prevalence of F species HAdVs serotype 41 (79.2%) and C species PAdVs serotype 5 (18.1%) was higher than that of other serotypes. Among NoVs, genogroup GII was more prevalent than GI. In particular, GII.4 (21.2%) and GII.17 (18.2%) were the predominant genotypes, which was consistent with the clinical findings. The prevalence of both AdVs and NoVs was higher in the winter than spring, summer and autumn seasons. AdVs and NoVs detection results were statistically analyzed by investigating their association with water quality indicators. The results revealed that the presence of AdVs was significantly correlated with the heterotrophic bacterial count, total coliform Escherichia coli, turbidity, salinity, and dissolved oxygen. Meanwhile, the presence of NoVs was only significantly correlated with temperature, pH, and dissolved oxygen. Microbial pollution sources may include urban runoff and discharge of water from livestock farms situated near the river and tributaries within this region of Taiwan. Future studies should include comparisons of the presence of AdVs and NoVs in these known pollution sources and water quality monitoring of these watersheds, as this will allow potential identification of pollution sources. Additionally, remediation strategies must be developed to minimize viral contamination in the river ecosystem.