Ornithinicoccus soli sp. nov., isolated from farmland soil.

A Gram-stain-positive, aerobic, non-motile and coccoid-shaped bacterium, designated XNB-1T, was isolated from farmland soil in Taian, Shandong province, China. Strain XNB-1T contained iso-C15 : 0 and iso-C16 : 0 as the predominant fatty acids. The diagnostic diamino acid of the peptidoglycan was ornithine, and the interpeptide bridge was l-Orn←Gly(1, 2)←d-Glu. The polar lipid profile of strain XNB-1T consisted of diphosphatidylglycerol, phosphatidylglycerol, an unidentified phosphoglycolipid and three unidentified phospholipids. The predominant menaquinone of strain XNB-1T was MK-8(H4) and the DNA G+C content was 70.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain XNB-1T belonged to the genus Ornithinicoccus, and shared the highest similarity with Ornithinicoccus hortensis HKI 0125T (96.0 %), followed by Ornithinicoccus halotolerans EGI 80423T (95.5 %). Genome-based analysis of average nucleotide identity of strain XNB-1T with O. hortensis HKI 0125T and O. halotolerans EGI 80423T yielded values of 73.1 and 73.3 %, respectively, while the digital DNA-DNA hybridization values were 19.5 and 19.9 %, respectively. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain XNB-1T is considered to represent a novel species of the genus Ornithinicoccus, for which the name Ornithinicoccus soli sp. nov. is proposed. The type strain is XNB-1T (=CCTCC AB 2019099T=KCTC 49259T).

Cumulibacter soli sp. nov., isolated from farmland soil.

A Gram-stain-positive, strictly aerobic, non-motile, non-spore-forming and rod-shaped bacterium, designated as strain G-1T, was isolated from farmland soil sampled in in Fuyang, Anhui Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain G-1T was closely related to Cumulibacter manganitolerans 2-36T (97.7 % similarity). Strain G-1T contained iso-C16 : 0, C17 : 1ω6c, iso-C15 : 0 and iso-C14 : 0 as the predominant fatty acids. The polar lipids of strain G-1T were diphosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid, an unidentified lipid and two unidentified glycolipids. The predominant respiratory quinone of strain G-1T was MK-9(H4). The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid. The G+C content of the genomic DNA based on genome calculations was 64.2 mol%. Average nucleotide identity and the digital DNA-DNA hybridization values for the draft genomes between strain G-1T and strain 2-36T were 75.7 and 20.2 %, respectively. On the basis of phenotypic and phylogenetic data, strain G-1T is considered to represent a novel species of the genus Cumulibacter, for which the name Cumulibacter soli sp. nov. is proposed. The type strain is G-1T (=CCTCC AB2019021T=KCTC 49258T).

Pedobacter agrisoli sp. nov., isolated from farmland soil.

A Gram-stain-negative, aerobic, non-motile, non-spore-forming and rod-shaped bacterium, designated YHM-9T, was isolated from soil in Yangquan, Shanxi Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YHM-9T belonged to the genus Pedobacter and shared the highest similarity (97.4 %) to the type strain Pedobacter lignilitoris W-WS13T. Strain YHM-9T exhibited low DNA-DNA relatedness with P. lignilitoris W-WS13T (21.7±1.3 %). The DNA G+C content was 38.9 mol%. The major fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and iso-C17 : 0 3-OH. The respiratory quinone was MK-7, the major polyamine was sym-homospermidine and the major polar lipids were phosphatidylethanolamine. Based on the morphological, physiological, biochemical and chemotaxonomic characteristics, strain YHM-9T was recognized as a representative of a novel species within the genus Pedobacter, for which the name Pedobacteragrisoli sp. nov. is proposed. The type strain is YHM-9T (=JCM 32093T=CCTCC AB 2017125T).

[An ecological stoichiometry model based on the size of Nitraria tangutorum]. / 基于白刺个体大小的生态化学计量模型.

Ecological stoichiometry provides a new method for understanding the characteristics, driving forces and mechanisms of C, N and P coupled cycles. However, there are few reports on the variation in ecological stoichiometry of plants during their growth. In this study, we fitted the total elemental mass of different module based on the size of Nitraria tangutorum, and derived the ecological stoichiometry models of different module and whole ramet by measuring the biomass and nutrient concentrations of the current-year stems in 2017, 2-year-old stems, more than 2-year-old stems, leaves, roots and layerings of N. tangutorum ramet. Our results showed that the derivation model could well reflect the changes in ecological stoichiometry during plant growth. The old stems and the layering had higher N:P and C:P, while leaves,current-year stems, and roots had lower N:P and C:P. The whole plant nutrient elements cumulative rate was P:N:C during the growth process. These results were consistent with the growth rate hypothesis and allometric theory, and provide evidence for nutrient reabsorption. This model could be used as an effective way to analyze the dynamic characteristics of elements in plant growth.