He, Jian

A Gram-stain-negative, non-motile, rod-shaped and imazamox-resistant bacterium, designated as H34T, was isolated from soil obtained from a farmland. Strain H34T grew at pH 6.0–9.0 (optimum, 7.0), temperature 15–40 °C (optimum, 30 °C) and salinity of 0–3.0% NaCl (optimum 0.5% NaCl, w/v). Phylogenetic analysis of the 16S rRNA gene and genome sequences showed that strain H34T was affiliated to the family Chitinophagaceae but formed a distinct phyletic branch. The values of 16S rRNA gene sequence similarity, average nt identity (ANI), digital DNA–DNA hybridization (dDDH) and average aa identity (AAI) between strain H34T and closely related type strains of the genera Flavisolibacter, Paraflavisolibacter, Paracnuella, Flaviaesturariibacter and Cnuella were 90.9–92.6%, 68.4–72.1%, 18.7–20.5% and 60.5–65.9%, respectively. The genome size was 7.01 Mb with a G+C content of 56.5 mol%. The major fatty acids (≥10%) were iso-C15 : 0, iso-C15 : 1 G and C16 : 1  ω5c. The only isoprenoid quinone was menaquinone-7. The major polar lipids were phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified aminophosphoglycolipid, two unidentified phospholipids, three unidentified aminolipids and four unidentified lipids. The distinct phylogenetic relationships; low values of 16S rRNA gene sequence similarity, AAI, ANI and dDDH; and the differences in phenotypic and genotypic characteristics support that strain H34T represents a novel species in a novel genus in the family Chitinophagaceae, for which the name Huijunlia imazamoxiresistens gen. nov., sp. nov. is proposed (type strain H34T=MCCC 1K09117T=KCTC 102287T).

The ‘Cuimi’ kumquat is a unique citrus cultivar known for its thin, crisp pulp and sweet, aromatic flavor. In addition to its use in fresh consumption and processing, this variety exhibits certain medicinal properties. This study aims to investigate the genetic diversity of the Huanglongbing (HLB) bacterium across different tissues of the ‘Cuimi’ kumquat, offering a theoretical basis for understanding the HLB epidemic in Dechang County, Sichuan. The research focuses on the absolute quantification of the HLB bacterium in seven specific tissues of the ‘Cuimi’ kumquat, including new leaves, upper phloem of branches, fruit peduncle, pith, fruit axis, old leaves, and lower phloem of branches. Additionally, the types and contents of prophages were identified in these tissues. In the same diseased branch group, Candidatus Liberibacter asiaticus (CLas) exhibited an uneven distribution, with the highest concentration detected in the pith, significantly surpassing levels found in the stem and leaf tissues (new leaves, upper phloem of branches, old leaves, lower phloem of branches). Infected fruit peduncles and pith slices showed noticeable shrinkage and collapse in the phloem. Prophage analysis indicated that multiple types of prophages could be simultaneously detected within the same infected ‘Cuimi’ kumquat branch. New shoot tissues contained both Type 2 and Type 4 prophages, with a relatively higher abundance of Type 4 and a lower abundance of Type 2. The relative abundance of Type 1 prophage in the fruit tissues was generally higher than in other tissues. CLas primarily accumulates in the fruit tissues of the ‘Cuimi’ kumquat, and the situation in Dechang County suggests that individual trees may be infected with multiple prophage strains simultaneously.

A Gram-stain-negative bacterium, designated LG-2T, was isolated from sludge collected at a pesticide-manufacturing factory in Jiangsu Province, PR China. Cells of strain LG-2T were strictly aerobic, non-motile and spherical. Growth was observed at 15–42 °C (optimum, 30 °C), pH 6.0–9.0 (optimum, pH 7.0) and 0–3.0 % (w/v) NaCl (optimum, 1.0 %). LG–2T showed 95.5–96.9 % 16S rRNA sequence similarity to type strains in the genera Pusillimonas, Bordetella, Parapusillimonas, Candidimonas and Paracandidimonas of the family Alcaligenaceae. The phylogenomic tree indicated that strain LG-2T was clustered in the family Alcaligenaceae and formed a clade with Paracandidimonas soli IMT-305T, while the phylogenetic trees based on 16S rRNA gene sequences indicated that strain LG-2T formed a distinct clade within the family Alcaligenaceae. The average nucleotide identity, digital DNA–DNA hybridization and average amino acid identity values between LG-2T and its closely related type strains in the genera Pusillimonas, Bordetella, Parapusillimonas, Candidimonas and Paracandidimonas were 70.8–75.3, 18.9–23.7 and 59.6 %–69.3 %, respectively. The major cellular fatty acids were C16 : 0, C17 : 0 cyclo, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and summed feature 2 (C12 : 0 aldehyde and/or unknown 10.928). The predominant menaquinone was Q-8. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, two aminophospholipids, three aminolipids and nine unknown polar lipids. The genome size of strain LG-2T was 3.2 Mb and the DNA G+C content was 63.4 mol%. On the basis of the phenotypic, phylogenetic and genomic results from this study, strain LG-2T represents a novel species of a new genus in the family Alcaligenaceae, for which the name Yanghanlia caeni gen. nov., sp. nov. is proposed, with strain LG-2T (=KCTC 8084T= CCTCC AB 2023123T) as the type strain.