Municipal wastewater treatment plants (WWTPs) use functional microorganisms in activated sludge (AS) to reduce the environmental threat posed by wastewater. In this study, Illumina NovaSeq sequencing of 16S rRNA genes was performed to explore the microbial communities of AS at different stages of the two WWTP projects in Shenzhen, China. Results showed that Proteobacteria, Bacteroidetes, Acidobacteria, Firmicutes, and Nitrospirae were the dominant phyla in all the samples, with Proteobacteria being the most abundant and reaching a maximum proportion of 59.63%. There was no significant difference in biodiversity between the two water plants, but Stage 1 and Stage 2 were significantly different. The Mantel test indicated that nitrate, total nitrogen (TN), chemical oxygen demand (COD), and nutrients were essential factors affecting the bacterial community structure. FAPROTAX analysis emphasized that the leading functional gene families include nitrification, aerobic nitrite oxidation, human pathogens, and phototrophy. This study reveals changes in the community structure of AS in different treatment units of Banxuegang WWTP, which can help engineers to optimize the wastewater treatment process.

Chemical epigenetic manipulation was applied to a deep marine-derived fungus, Aspergillus sp. SCSIOW3, resulting in significant changes of the secondary metabolites. One new diphenylether-O-glycoside (diorcinol 3-O-α-D-ribofuranoside), along with seven known compounds, were isolated from the culture treated with a combination of histone deacetylase inhibitor (suberohydroxamic acid) and DNA methyltransferase inhibitor (5-azacytidine). Compounds 2 and 4 exhibited significant biomembrane protective effect of erythrocytes. 2 also showed algicidal activity against Chattonella marina, a bloom forming alga responsible for large scale fish deaths.

Design of elaborated nanomaterials to improve the therapeutic efficacy and mitigate the side effects of chemotherapeutic anticancer drugs, such as Doxorubicin (Dox), is significant for cancer treatment. Here, we describe a co-assembled strategy, where amphiphile short peptides are co-assembled with Doxorubicin to form nanoscale particles for enhanced delivery of Dox. Two kinds of short peptides, Fmoc-FK (FK) and Fmoc-FKK (FKK), are synthesized. Through adjusting the component ratio of peptide and Dox, we obtain two kinds of co-assembled nanoparticles with homogeneous size distributions. These nanoparticles show several distinct characteristics. First, they are pH-responsive as they are stable in alkaline and neutral conditions, however, de-assembly at acidic pH enables selective Dox release in malignant cancer cells. Second, the nanoparticles show an average size of 50–100 nm with positive charges, making them effective for uptake by tumor cells. Moreover, the side effects of Dox on healthy cells are mitigated due to decreased exposure of free-Dox to normal cells. To conclude, the co-assembled peptide-Dox nanoparticles exhibit increased cellular uptake compared to free-Dox, therefore causing significant cancer cell death. Further apoptosis and cell cycle analysis indicates that there is a synergistic effect between the peptide and Doxorubicin.

Understanding how bacterial communities adapt to different environmental factors provides a scientific basis for developing and utilizing microbial resources in rivers. This study investigated the changes in the microbial communities of water and mud samples from two sites of an urban river (GH: Gonghe Village and YC: Yanchuan). Analysis of the water samples showed that site GH had higher concentrations of ammonium, total nitrogen, Mn, and Ni than site YC. High-throughput sequencing was used to analyze the community composition of the samples. The results showed that the dominant phyla were Proteobacteria, Bacteroidete, Actinobacteria, and Chloroflexi. The alpha diversity of the microbial community in the mud samples was higher than in the water samples. Moreover, the relative abundance of the dominant genus varied a lot between the samples, with the highest relative abundance of Arcobacter and Vibrio found in the water samples at site GH in January and October, respectively. The correlation analysis showed that pH, TN, manganese, and fluoride were the main environmental factors that affected the composition and structure of the microbial communities. The phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis showed that species associated with nitrogen metabolism differed between the sampling sites. In addition, potential pathogens, such as Vibrio and Arcobacter, which may pose potential risks to the environment and human health, were found in the samples.

Heterocyte-forming cyanobacteria form symbiotic relationships with several lineages of plants. Here, twenty (20) strains of endosymbiotic cyanobacteria (cyanobionts) with Nostoc-like morphologies were isolated from the highly specialized coralloid roots of five host species in Cycadales—Cycas debaoensis, C. fairylakea, C. elongata, Ceratozamia robusta, and Macrozamia moorei. Molecular phylogeny based on the 16S rRNA gene placed these strains into seven different taxa within the Nostocaceae, specifically under the genera Desmonostoc and Dendronalium. The percent dissimilarity and unique patterns in the secondary structures of the D1-D1′, Box-B, V2, and V3 helices, which were based on the 16S–23S rRNA internal transcribed spacer (ITS) regions, supported three distinct species in Desmonostoc. These three morphologically distinct novel species are described in this report: Desmonostoc debaoense sp. nov., Desmonostoc meilinense sp. nov., and Desmonostoc xianhuense sp. nov. Other investigated strains were phylogenetically identified as members of the recently discovered genus Dendronalium and represent the first report of association of that genus with cycads. Our findings suggest that the order Cycadales hosts diverse species of cyanobionts in their coralloid roots and that many potential unreported or novel taxa are present in cycads occurring in their natural habitat and await discovery.

A novel cyanobacterial strain (CSML-F035) here described as Stenomitos nagquensis sp. nov. was isolated from a plateau meadow wetland habitat in the Tibet Autonomous Region. The novel strain was studied based on a polyphasic approach by combining characteristics of cell morphology and evidence from molecular data and ecology. Phylogenetic analyses based on the 16S rRNA and rbcL genes indicated that the novel strain is a member of the genus Stenomitos (Leptolyngbyaceae) but is positioned in a unique clade, with strongly supported values from BI, ML, and NJ methods. The percentage similarity of the 16S rRNA gene sequence of CSML-F035 compared with known strains of Stenomitos was >97%. Morphologically, S. nagquensis sp. nov. possesses overlapping morphological characteristics with other Stenomitos species, with thin trichomes enclosed in a firm, colorless, hyaline, persistent mucilage. However, the strain appeared to have slightly smaller cells compared to most known species of Stenomitos. Further analyses of the 16S–23S ITS region showed dissimilarity at 11.2–22.8% compared to known species of Stenomitos. The secondary helices—including D1–D1, V2, Box–B, and V3—that were predicted based on the 16S–23S ITS region for Stenomitos nagquensis sp. nov. were also distinct, thereby providing strong additional support for the separation of this species. This study highlights the importance of unexplored habitats in the Tibet region in which cyanobacterial diversity can be deemed high, with many potential new species that remain poorly explored.