A non-symbiotic novel species, Rhizobium populisoli sp. nov., isolated from rhizosphere soil of Populus popularis.

Strain XQZ8T, isolated from the rhizosphere soil of a Populus popularis plant in China, was characterized using a polyphasic taxonomic approach. Cells were Gram-negative, aerobic, non-spore-forming, and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain XQZ8T was related to members of the genus Rhizobium and had the highest 16S rRNA gene sequence similarity to Rhizobium smilacinae PTYR-5T (96.6%). The average nucleotide identity and digital DNA-DNA hybridization value between strain XQZ8T and R. smilacinae PTYR-5T were 77.5% and 21.4%, respectively. TYGS whole-genome-based taxonomic and multi-locus sequence analyses of three concatenated housekeeping genes (atpD-recA-glnII) further indicated that strain XQZ8T was a new member of the genus Rhizobium. The major cellular fatty acids included summed feature 8 (C18:1 ω7c/C18:1 ω6c), summed feature 2 (C12:0 aldehyde/unknown 10.928), C16:0, and C19:0 cyclo ω8c. The major respiratory quinones were Q-9 and Q-10. The polar lipids were phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine, an unidentified glycophospholipid, and three unidentified lipids. The genomic DNA G + C content of the strain was 60.1 mol%. Based on the phylogenetic, phenotypic, and genotypic characteristics, strain XQZ8T represents a novel species of the genus Rhizobium, for which the name Rhizobium populisoli sp. nov. is proposed. The type strain is XQZ8T (= JCM 34442T = GDMCC 1.2201T).

In Vitro Antibacterial and Antitumor Activity of Total Triterpenoids from a Medicinal Mushroom Sanghuangporus sanghuang (Agaricomycetes) in Liquid Fermentation Culture.

We analyzed the biological activity and composition of total triterpenoids extracted from the liquid fermentation culture of the medicinal mushroom Sanghuangporus sanghuang. S. sanghuang total triterpenoid extract (STTE) had the strongest inhibitory effect on Staphylococcus aureus, and STTE at 2-fold the minimum inhibitory concentration had a significant effect on the growth of four types of bacteria and caused marked nucleic acid leakage. Scanning electron microscopy confirmed that STTE destroyed bacterial cell walls. STTE also significantly inhibited the proliferation of Caco-2 cells and disrupted their morphology. Flow cytometry revealed that STTE induced cell cycle arrest and induced early and late apoptosis of Caco-2 cells. Infrared spectroscopy, and gas chromatography-mass spectrometry resulted in the detection of a variety of triterpenoids (e.g., pentacyclic triterpenoid, lanolinane triterpenoid, and trans-squalene) as well as other small molecules (e.g., esters, acids, and aldehydes). Our findings indicate that STTE has antibacterial and antitumor activity and will enable screening of novel fungal-derived anticancer and antibacterial compounds.