Genome­based classification of the family Natrialbaceae and description of four novel halophilic archaea from three saline lakes and a saline-alkaline land.

The current representatives of the family Natrialbaceae within the class Halobacteria were subjected to phylogenetic, phylogenomic, and comparative genomic analyses. The current species of Halobiforma and Halomontanus were found to be related to those of Natronobacterium and Natronoglomus, respectively. According to the cutoff value of average amino acid identity (AAI) (≤ 76%) proposed to differentiate genera within the family Natrialbaceae, Halobiforma, and Natronoglomus should be merged with Natronobacterium and Halomontanus, respectively. Beyond these, four novel halophilic archaeal strains, CCL63T, AD-5T, CG52T, and KLK7T, isolated from three saline lakes and a saline-alkaline land in China, were simultaneously subjected to polyphasic classification. The phenotypic, phylogenetic, phylogenomic, and comparative genomic analyses indicated that strain CCL63T (= CGMCC 1.18663T = JCM 35096T) represents a novel genus of the family Natrialbaceae, strains AD-5T (= CGMCC 1.13783T = JCM 33734T) and CG52T (= CGMCC 1.17139T = JCM 34160T) represent two novel species of the genus Natronococcus, and strain KLK7T (= MCCC 4K00128T = KCTC 4307T) represents a novel species of Haloterrigena. Halovalidus salilacus gen. nov., sp. nov., Natronococcus wangiae sp. nov., Natronococcus zhouii sp. nov., and Haloterrigena salinisoli sp. nov. are further proposed based on these type strains accordingly.

Salinirarus marinus gen. nov., sp. nov., Haloplanus salilacus sp. nov., Haloplanus pelagicus sp. nov., Haloplanus halophilus sp. nov., and Haloplanus halobius sp. nov., halophilic archaea isolated from commercial coarse salts with potential as starter cultures for salt-fermented foods.

Five halophilic archaeal strains, XH8T, CK5-1T, GDY1T, HW8-1T, and XH21T, were isolated from commercial coarse salt produced in different regions of China. Their 16S rRNA and rpoB' gene sequences indicated that four of the strains (CK5-1T, GDY1T, HW8-1T, and XH21T) represent distinct species within the genus Haloplanus (family Haloferacaceae), while strain XH8T represents a novel genus within the same family. These assignments were supported by phylogenetic and phylogenomic analyses, which showed that strains CK5-1T, GDY1T, HW8-1T, and XH21T cluster with the current species of the genus Haloplanus, while strain XH8T forms a separate branch from the genus Haloplanus. The digital DNA-DNA hybridization and average amino acid identity (AAI) values among these four strains and the current members of the genus Haloplanus were 23.1%-35.2% and 75.9%-83.8%, respectively; and those values between strain XH8T and other genera in the family Haloferacaceae were 18.8%-33.6% and 59.8%-66.6%, respectively, much lower than the threshold values for species demarcation. Strain XH8T may represent a novel genus of the family Haloferacaceae according to the cut-off value of AAI (≤72.1%) proposed to differentiate genera within the family Haloferacaceae. These five strains could be distinguished from the related species according to differential phenotypic characteristics. Based on these results, it is proposed that strain XH8T represents a novel genus within the family Haloferacaceae, and strains CK5-1T, GDY1T, HW8-1T, and XH21T represent four novel species of the genus Haloplanus, respectively. Additionally, these five strains possess genes encoding enzymes critical for the fermentation process in salt-fermented foods, indicating their potential as starter cultures for these applications.

Genome-based classification of the family Haloferacaceae and description of five novel species of Halobaculum.

The taxonomic status of some species of Halobellus, Haloferax, Halogranum, and Haloplanus within the family Haloferacaceae was elucidated by phylogenetic, phylogenomic, and comparative genomic analyses. The relative species of each genus should constitute a single species based on the overall genome-related indexes proposed for species demarcation. The cutoff values of AAI (72.1%), ANI (82.2%), and rpoB' gene similarity (90.7%) were proposed to differentiate genera within the family Haloferacaceae. According to these standards, a novel genus related to the genus Halobaculum was proposed to accommodate Halobaculum halophilum Gai3-2 T and Halobaculum salinum NJ-3-1 T. Five halophilic archaeal strains, DT31T, DT55T, DT92T, SYNS20T, and YSMS11T, isolated from a tidal flat and a marine solar saltern in China, were subjected to polyphasic classification. The phenotypic, phylogenetic, phylogenomic, and comparative genomic analyses revealed that strains DT31T (= CGMCC 1.18923 T = JCM 35417 T), DT55T (= CGMCC 1.19048 T = JCM 36147 T), DT92T (= CGMCC 1.19057 T = JCM 36148 T), SYNS20T (= CGMCC 1.62628 T = JCM 36154 T), and YSMS11T (= CGMCC 1.18927 T = JCM 34912 T) represent five novel species of the genus Halobaculum, for which the names, Halobaculum lipolyticum sp. nov., Halobaculum marinum sp. nov., Halobaculum litoreum sp. nov., Halobaculum halobium sp. nov., and Halobaculum limi sp. nov., are proposed.

[Provincial-scale Soil As Migration and Transformation and Rice Safe Planting Zoning: A Case Study of Guizhou Province].

To explore the distribution characteristics of paddy soil and rice AS content, as well as the health risks of rice consumption, and to evaluate the safe planting ability of rice, 209 paddy soil samples and 1 567 groups of paddy soil-rice samples were collected, their As content and basic soil physical and chemical properties were determined, and the single-factor pollution index method was used to evaluate the pollution degree of the samples. The results showed that:① the soil of paddy fields in Guizhou Province was mainly neutral, and its fertilizer retention capacity and organic matter content were above the medium level, and the soil was relatively fertile. The range of ω(As) in paddy soil was 0.042-91.75 mg·kg-1, the geometric mean was 10.03 mg·kg-1, and the cumulative effect of paddy soil As was lower than that of natural soil As (P<0.05) by independent sample T. Compared with the screening value (0.2 mg·kg-1) of the Soil Pollution Risk Management and Control Standard for Agricultural Land (GB 15618-2018), the excess rate of soil samples was 15.37%. ② The ω (As) range of rice grain samples was 0.001-0.937 mg·kg-1, the geometric average value was 0.108 mg·kg-1, 10.21% of the rice grain samples exceeded the limit value of "Limit of Contaminants in Food (trial)" (GB 2762-2022), and the locations where the exceedances are mainly found are in the central and northern parts of Qiannan Prefecture, as well as around industrial and mining activity zones in the southern counties and districts of Zunyi. ③ As ingested through rice posed non-carcinogenic risk and carcinogenic risk for adults and children, and the impact on children was greater than that of adults. There is no strict control area for safe rice planting in Guizhou Province, and rice can be safely planted.

[Low Accumulation Characteristics of Sweet-waxy Maize in Pb and Cd Complex Contaminated Soils Based on Field Trials].

To screen out sweet-waxy maize varieties with low accumulation characteristics suitable for planting in lead (Pb) and cadmium (Cd) complex contaminated soils, 39 maize varieties were selected, and the enrichment characteristics and differences of grains and straws on Pb and Cd were studied through field trials. Maize yield, bioaccumulation factors, and soil Pb and Cd risk thresholds were used as evaluation indicators for screening low accumulation maize varieties. The results showed that there were significant differences between the yield and Pb and Cd contents in grains and straws of different varieties of maize (P<0.05). Bioaccumulation factors of grains for Pb and Cd were in the range of 0.00003-0.00230 and 0.01-0.15, respectively, and those of straws for Pb and Cd were in the range of 0.003-0.065 and 0.64-4.28, respectively. Through the cluster analysis of bioaccumulation factors, the soil Pb and Cd risk thresholds of different varieties of maize were comprehensively obtained:Huitian 5, Xinmeitian 818, and Yunuo 9 could be safely produced in the farmland with Pb and Cd content exceeding the risk control value, and Tianguinuo 937 and Jinwannuo 2000 could be safely produced in the farmland with Cd content exceeding the risk screening value. Huitian 5, Xinmeitian 818, and Yunuo 9, as low Pb and Cd accumulation varieties, were suitable to be popularized on Pb and Cd polluted soil in Guangxi, China. Tianguinuo 937 and Jinwannuo 2000, as low grain and high Cd accumulation varieties, are suggested to be used as phytoremediation resources.

Antibacterial Metabolites from Kiwi Endophytic Fungus Fusarium tricinctum, a Potential Biocontrol Strain for Kiwi Canker Disease.

Pseudomonas syringae pv. actinidiae (Psa) is a Gram-negative bacterium causing the kiwifruit canker disease, resulting in serious economic losses to the kiwifruit industry. This study investigated the use of an endophytic fungus, Fusarium tricinctum, obtained from the kiwi plant (Actinidia chinesis) as a potential biocontrol strain against the Psa. F. tricinctum showed an inhibition rate of 59.5% in vitro against Psa. Bioassay-guided isolation was conducted on the cultural broth of F. tricinctum and seven new imidazole alkaloids, (±)-fusaritricine J ((±)-1) and fusaritricines K-P (2-7), and four enniatins (8-11) were identified. Their absolute configurations were established through extensive spectroscopic methods, quantum chemical calculations, and X-ray single crystal diffraction. Compounds 1, 4, 5, and 8-11 showed comparable anti-bacterial activities against Psa as positive control, with MIC values of 25-50 µg/mL. Further cell membrane permeability assay suggested that the most active compound 4 could destroy the bacterial cell wall structure. Hence, F. tricinctum metabolites could be applied as potential anti-Psa agents, and F. tricinctum could be considered a biocontrol strain for the control of the kiwifruit canker disease.

Lanostane triterpenoids from the fungus Physisporinus vitreus and their inhibitory activity against nitric oxide production.

Eight undescribed lanostane triterpenoids, physivitrins A-H, along with four known analogues, were isolated from cultures of the fungus Physisporinus vitreus. Their structures were elucidated on the basis of extensive spectroscopic methods, in which the absolute configuration of physivitrin A was elucidated using electronic circular dichroism calculation and nuclear magnetic resonance (NMR) calculation with DP4+ analysis. Physivitrins B and C showed inhibitory activities against nitric oxide (NO) production in LPS-activated RAW264.7 macrophages with IC50 values of 7.5 and 23.5 µM, respectively. Meanwhile, proinflammatory cytokines (TNF-α, iNOS and IL-1ß) mRNA expression was also inhibited by physivitrin B significantly.

[Accumulation Effects and Health Risks of Heavy Metals in Rice in Location-based Cadmium Anomaly Area in Liuzhou].

In order to explore the migration and transformation characteristics of soil heavy metals in rice in an area of ground source cadmium anomaly and to evaluate the safe planting of rice, a total of 91 pairs of soil and rice samples were collected from paddy fields in the typical area of Liuzhou city, Guangxi province, and the contents of heavy metals such as Cd, soil pH, and organic matter were tested. The results showed that:① Cd, Cu, Ni, and Zn in the paddy field exceeded the background values of 92.31%, 34.07%, 36.26%, and 90.11%, respectively. Compared with the screening values in the Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard, Cd and Zn exceeded 30.53% and 25.26%, respectively. Super standard points were mainly distributed in Fushi Town. ② Cd and Ni exceeded 35.16% and 3.30%, respectively, and Daliang town had the highest Cd enrichment coefficient and Cd exceeded rate. ③ Correlation analysis showed that soil pH was the main influencing factor of heavy metals in rice, and Cd and Ni had similar pollution sources in rice. ④ The results of rice health risk assessment showed that the THQ value of rice Cd in Daliang town was greater than 1.0, indicating the potential health risk of rice Cd in this area. The TTHQ values were all greater than 1.0, indicating that the risks to children were higher than those to adult women, which were higher than those of adult men, showing that reasonable dietary structure is crucial to prevent heavy metal intake in different ages and genders. Therefore, there are certain risks in rice planting in the Liuzhou area of ground source cadmium anomaly, which need to be controlled using different safety utilization measures.

Author Correction: Co-delivery of docetaxel and silibinin using pH-sensitive micelles improves therapy of metastatic breast cancer.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Co-delivery of docetaxel and silibinin using pH-sensitive micelles improves therapy of metastatic breast cancer.

Breast cancer is the most vicious killer for women, and tumor metastasis is one of the leading causes of breast cancer therapy failure. In this study, a new pH-sensitive polymer (polyethylene glycol-block-poly[(1,4-butanediol)-diacrylate-ß-N,N-diisopropylethylenediamine], BDP) was synthesized. Based on BDP, docetaxel/silibinin co-delivery micelles (DSMs) was constructed. DSM had a well-defined spherical shape under the transmission electron microscope with average hydrodynamic diameter of 85.3±0.4 nm, and were stable in the bloodstream but could dissociate to release the chemotherapeutic agents in the low pH environment of the endo/lysosomes in the tumor cells. Compared with free drugs, DSM displayed greatly enhanced cellular uptake, higher cytotoxicity and a stronger anti-metastasis effect against mouse breast cancer cell line 4T1. In 4T1 tumor-bearing mice treated with DSM (twice a week for 3 weeks), the inhibition rate on tumor growth and metastasis reached 71.9% and 80.1%, respectively. These results reveal that DSM might be a promising drug delivery system for metastatic breast cancer therapy.