Pi-Han Wang

A gravel contact oxidation system is an ecological engineering packed-bed reactor that uses gravel as a biofilm carrier to remove waterborne contaminants. While widely studied for pollution control, little is known about its microbial communities. In this study, we evaluated the system's effectiveness in reducing coliform bacteria, including antibiotic-resistant and hemolytic strains, as indicators of pollution and public health risk in Dongda Creek, Taiwan. Results showed a significant reduction in coliform levels, from 105–106 CFU/100 mL to 102 CFU/100 mL, along with notable improvements in water quality parameters like turbidity, total dissolved solids, and oxidation–reduction potential. Antibiotic-resistant coliforms were less prevalent in treated water, demonstrating the system's efficacy in control of bacterial flora that poses a risk to public health. Third-generation sequencing revealed reduced species richness in treated wastewater, while biofilm samples showed greater bacterial diversity. Gravel's surface area supported biofilm formation, promoting microbial communities capable of degrading organic pollutants. The activity of biofilm microbial community also decreased turbidity and dissolved solids, while shifting bacterial composition in the wastewater. These findings underscore the system's potential as a sustainable, effective model for ecological wastewater treatment.

Mycoheterotrophic plants (MHPs) rely on their mycorrhizal fungus for carbon and nutrient supply, thus a shift in mycobionts may play a crucial role in speciation. This study aims to explore the mycorrhizal diversity of two closely related and sympatric fully MHPs, Monotropastrum humile var. humile (Mhh) and M. humile var. glaberrimum (Mhg), and determine their mycorrhizal associations. A total of 1,108,710 and 1,119,071 ectomycorrhizal fungal reads were obtained from 31 Mhh and 31 Mhg, and these were finally assigned to 227 and 202 operational taxonomic units, respectively. Results show that sympatric Mhh and Mhg are predominantly associated with different fungal genera in Russulaceae. Mhh is consistently associated with members of Russula, whereas Mhg is associated with members of Lactarius. Associating with different mycobionts and limited sharing of fungal partners might reduce the competition and contribute to their coexistence. The ectomycorrhizal fungal communities are significantly different among the five forests in both Mhh and Mhg. The distinct mycorrhizal specificity between Mhh and Mhg suggests the possibility of different mycobionts triggered ecological speciation between sympatric species.

Spider silk is a promising material with great potential in biomedical applications due to its incredible mechanical properties and resistance to degradation of commercially available bacterial strains. However, little is known about the bacterial communities that may inhabit spider webs and how these microorganisms interact with spider silk. In this study, we exposed two exopolysaccharide-secreting bacteria, isolated from webs of an orb spider, to major ampullate (MA) silk from host spiders. The naturally occurring lipid and glycoprotein surface layers of MA silk were experimentally removed to further probe the interaction between bacteria and silk. Extensibility of major ampullate silk produced by Triconephila clavata that was exposed to either Microbacterium sp. or Novosphigobium sp. was significantly higher than that of silk that was not exposed to bacteria (differed by 58.7%). This strain-enhancing effect was not observed when the lipid and glycoprotein surface layers of MA silks were removed. The presence of exopolysaccharides was detected through NMR from MA silks exposed to these two bacteria but not from those without exposure. Here we report for the first time that exopolysaccharide-secreting bacteria inhabiting spider webs can enhance extensibility of host MA silks and silk surface layers play a vital role in mediating such effects.

Scytinopogon cryptomerioides (Trechisporales, Basidiomycota) is described as a new species collected from Cryptomeria japonica plantations in Taiwan. This new species is characterized by a white basidiome with dichotomous and flattened branches, clamped hypha, ampullate septa, clavate basidia with four sterigmata, and colorless, ellipsoid, echinulate or verrucose spores with acute warts or spines. Based on the phylogeny constructed from a combined dataset of ITS-nrLSU sequences, S. cryptomerioides nested within the Trechispora clade, sister to Trechispora copiosa.