Titanium dioxide nanoparticle (n-TiO 2 ) is a widely used nanomaterial, which is inevitably released as a residue into aquatic ecosystems during material production and usage. However, the effects of n-TiO 2 on aquatic microbial communities have not been completely elucidated. This study examined the toxic effects of n-TiO 2 on eukaryotic and prokaryotic microbial communities in freshwater environments. We determined that n-TiO 2 had a greater inhibitory effect on the growth of eukaryotic algae than cyanobacteria in monocultures. A similar phenomenon was observed in a microcosm experiment, revealing that n-TiO 2 slightly reduced the content of chlorophyll-a but evidently increased the phycocyanin content. Moreover, the alpha diversity of the eukaryotic community was not affected, whereas its beta diversity increased with exposure to n-TiO 2 . Although n-TiO 2 altered the composition of freshwater microbial communities, it did not change the functions of the prokaryotic community, which might be attributed to the functional redundancy of microbiota. Co-occurrence network analysis indicated that n-TiO 2 destabilized the freshwater community, especially the eukaryotic community, and potentially disturbed the aquatic ecosystem. Our study revealed that the ecological risk of n-TiO 2 on aquatic microbial communities is complex; hence, rational utilization of n-TiO 2 should be emphasized.
Introduction: Microorganisms as a component of scalp ecosystem play a vital role in human scalp health. Soapberry pericarp is employed in improving scalp health, and its content of active ingredients could be enhanced resulted in fermentation. This study aims to investigate the effect of the fermentation filtrate from soapberry pericarp on the diversity of scalp microorganisms.Methods: The components in fermentation filtrate from soapberry pericarp were analyzed by HPLC-Q-Orbitrap HRMS, and 16S and ITS sequences of 198 samples from three different used stages (Day 0, Day 7, Day 28) were sequenced using the Illumina Novaseq platform. Microbial diversity was assessed using alpha diversity (Chao1 and Shannon indexes) and beta diversity (weighted unifrac and unweighted unifrac). Principal coordinate analysis (PCoA) and linear discriminant analysis (LDA) effect size analysis (LEfSe) were used to visualize microbial variation among different stages.Results: There were 22 components were identified in the fermentation filtrate from soapberry pericarp by HPLC-Q-Orbitrap HRMS. The alpha-diversity and beta-diversity analyses showed that scalp microbial diversity and composition were influenced by the fermentation filtrate of soapberry pericarp. Based on functional analysis, this study found an enrichment of healthy scalp-related bacterial pathways, such as amino acid, nucleoside, and nucleotide biosynthesis, while a decrease in fungal pathogenesis pathways, specifically saprotroph and symbiotroph pathways, was observed.Discussion: The study described about the complex community dynamics of human scalp microorganisms during the stages of using the fermentation filtrate from soapberry pericarp. This result will help rationally utilize the fermentation filtrate from soapberry pericarp to keep or improve human scalp health.
Lu Jia,Zukun Yang,Liuxu Sun,Qian Zhang,Yu Guo,Yulian Chen,Yang Dai,Yang Xia
Scaffold implantation for the repair of oral bone defects involves an interplay between the scaffold biomaterial and the microenvironment. However, previous studies on this subject have only considered the effects of the immune system and largely ignored those of the oral microbiota. Accordingly, in the present study, we prepared composite scaffolds comprising a three-dimensional poly( l -lactide- co -glycolide) matrix with a superparamagnetic iron oxide nanoparticle (SPION) coating and used a rat model to evaluate their palate-bone-regenerating effects and their interaction with the oral microbiota. It was found that the SPION coated scaffold induced better bone regeneration than that achieved by the controls. Furthermore, it significantly decreased the operational taxonomic units (OTU) numbers as determined by 16 s rRNA gene sequencing, and also resulted in decreased Chao and ACE alpha diversity indexes compared with those of the controls. However, it had no effect on beta diversity. SPION coated scaffolds caused a shift in oral bacterial composition characterized by a decrease in the Clostridium spp. population, and the dominant flora being Proteobacteria . Furthermore, SPION coated scaffolds upregulated the concentration of serum iron, hepcidin, and P1NP. Thus, SPION coated scaffolds enhanced bone regeneration, and this effect was partly related to alteration of the oral microbiota by the antibacterial effects of SPION. Our findings provide a better understanding of the role of oral microbiota in oral bone regeneration and how SPION coated scaffolds can be used to enhance it.
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