Altererythrobacter litoralis sp. nov., a New Carotenoid-Producing Member of the Family Erythrobacteraceae, Isolated from a Tidal Flat Sediment.

A new isolate designated as 1XM1-14T was isolated from a tidal flat sediment of Xiamen Island. The yellow-pigmented colonies and rod-shaped cells were observed. Strain 1XM1-14T could hydrolyze Tweens 20, 40, 60, aesculin, and skim milk, and was chemoheterotrophic and mesophilic, required NaCl for the growth. The 16S rRNA gene-based phylogenetic analysis indicated that strain 1XM1-14T was the most closely related to Altererythrobacter epoxidivorans CGMCC 1.7731T (97.0%), followed by other type strain of the genus Altererythrobacter with identities below 97.0%. The DNA-DNA hybridization and average nucleotide identity values between strain 1XM1-14T and its relatives of the genus Altererythrobacter were below the respective thresholds for prokaryotic species demarcation. The phylogenomic inference further revealed that strain 1XM1-14T formed a separate branch distinct from the type strains of the recognized species within the genus Altererythrobacter. The major cellular fatty acids of strain 1XM1-14T were identified as summed feature 8 (C18:1 ω6c and/or C18:1 ω7c), C17:1 ω6c, and C16:0; the profile of polar lipids comprised diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid, an unidentified glycolipid, and two unidentified lipids; the respiratory quinone was determined to ubiquinone-10. The genomic size and DNA G+C content of strain 1XM1-14T were 2.5 Mbp and 62.71%. The key carotenoid biosynthetic genes were determined in the genome of strain 1XM1-14T and the generated carotenoids were detected. The combined genotypic and phenotypic characteristics supported the classification of strain 1XM1-14T (= GDMCC 1.2383T = KCTC 82612T) as a novel species in the genus Altererythrobacter, for which the name Altererythrobacter litoralis sp. nov. is proposed.

Association between modifiable lifestyle pattern and periodontitis: a cross-sectional study based on NHANES.

BACKGROUND: Periodontitis can be avoided with a healthy lifestyle. However, studies have only looked at one lifestyle, ignoring the connection between lifestyle patterns and periodontitis. The purpose of this study was to look at the association between modifiable lifestyle patterns and periodontitis. METHODS: Data were obtained from the National Health and Nutrition Examination Survey in 2009-2010 and 2011-2012. Smoke, drink, exercise, sleep duration, oral exams, and self-rated oral health were all lifestyle factors. The CDC/AAP classification/case definition was used to evaluate periodontitis. Drawing upon latent class analysis, distinct patterns of lifestyle were identified, with each participant exclusively affiliated with a single pattern. The association between lifestyle classes and periodontitis was then examined using ordinal logistic regression. RESULTS: 4686 (52%) of the total 9034 participants, with a mean age of 54.08, were women. Three lifestyle latent classes were found by fitting 2-10 models: "Class 1" (52%), " Class 2" (13%), and " Class 3" (35%). The "Class 1" displayed a prevalence of oral examination (75%), favorable self-rated oral health (92%), and engagement in physical activity (50%). The 'Class 2' exhibited the lowest alcohol consumption (64%) and smoking rates (73%) but the highest prevalence of physical inactivity (98%). The 'Class 3' showed a tendency for smoking (72%), alcohol consumption (78%), shorter sleep duration (50%), absence of oral examinations (75%), and suboptimal self-rated oral health (68%). The influencing variables for the latent classes of lifestyle were age, education, and poverty level. Periodontitis risk may rise by 24% for each additional unhealthy lifestyle practiced by participants (OR = 1.24, 95% CI: 1.18-1.31). The 'Class 3' (OR = 1.80, 95% CI: 1.52-2.13) had a greater risk of periodontitis compared to the 'Class 1'. CONCLUSIONS: Our analysis revealed that unhealthy lifestyle patterns are associated with periodontitis. These different lifestyle patterns need to be taken into account when developing public health interventions and clinical care.

Gimibacter soli gen. nov. sp. nov., isolated from mangrove soil and insight into its ecological distribution and metabolic potential.

A Gram-stain-negative, facultatively anaerobic, motile and rod-shaped bacterium, designated as 6D33T, was isolated from mangrove soil. Growth was found to occur at 15-32 °C (optimum, 28 °C), at pH 6-9 (optimum, pH 7) and in 0-3 % NaCl (optimum, 1 %, w/v). The results of 16S rRNA gene-based analysis showed that strain 6D33T belonged to the family Temperatibacteraceae, sharing 93.1-94.4 % identity with its close neighbours within the genus Kordiimonas. The phylogenomic results indicated that strain 6D33T formed an independent branch distinct from type strains of the genus Kordiimonas. The overall genome relatedness indices of digital DNA-DNA hybridization, average nucleotide identity and amino acid identity values showed that strain 6D33T represents a novel species of a novel genus. The results of chemotaxonomic characterization indicated that the major cellular fatty acids of strain 6D33T were summed feature 9 (C16 : 0 10-methyl and/or iso-C17 : 1 ω9c), summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c) and iso-C15 : 0; the polar lipids comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminolipid and three unidentified lipids; the only respiratory quinone was ubiquinone-10. The genomic size and DNA G+C contents were 3.59 Mbp and 60.84 mol%, respectively. The 16S rRNA gene sequence reads abundance profiles revealed that the rare taxon is prevalent in marine environments, especially in sediments. Genome-scale metabolic reconstruction of strain 6D33T revealed a heterotrophic lifestyle and many pathways responsible for the degradation of aromatic compounds, suggesting application potential in aromatic hydrocarbon removal. Based on its genotypic and phenotypic characteristics, strain 6D33T is concluded to represent a novel species of the novel genus in the family Temperatibacteraceae, for which the name Gimibacter soli gen. nov. sp. nov. is proposed. The type strain of the type species is 6D33T (=GDMCC 1.1959T=KCTC 82335T).

Tsuneonella litorea sp. nov., a novel carotenoid-producing bacterium isolated from coastal sediment.

A Gram-stain-negative, aerobic, non-motile and pleomorphic bacterium designated as YG55T was isolated from a coastal sediment sample. Growth was found to occur at 10-37 °C (optimum, 28 °C), at pH 6-9 (optimum, pH 8) and in 0-6 % NaCl (optimum, 1 %). The results of 16S rRNA gene-based analysis showed that strain YG55T was related to the members of the genus Tsuneonella and shared the highest identity of 99.4 % with Tsuneonella dongtanensis GDMCC 1.2307T, followed by Tsuneonella troitsensis JCM 17037T (98.4 %). The phylogenomic results indicated that strain YG55T formed an independent branch distinct from the reference type strains. The 22.7 and 21.8 % digital DNA-DNA hybridization (dDDH) values and 83.0 and 81.8 % average nucleotide identity (ANI) values between strain YG55T and the two relatives were below the species definition thresholds of 70 % (dDDH) and 95-96 % (ANI), indicating that the strain represents a novel genospecies. The results of chemotaxonomic characterization indicated that the major cellular fatty acids of strain YG55T were summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c), C14 : 0 2OH and C16 : 0; the main polar lipids comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and sphingoglycolipid; the respiratory quinone was ubiquinone-10. The genomic size and DNA G+C contents were 3.03 Mbp and 66.98 %. The strain contained carotenoid biosynthesis genes and could produce carotenoids. Based on its genotypic and phenotypic characteristics, strain YG55T is concluded to represent a novel species of the genus Tsuneonella, for which the name Tsuneonella litorea sp. nov. is proposed. The type strain is YG55T (=GDMCC 1.2590 T=KCTC 82812T).

Terminal Residue and Dietary Risk Assessment of Atrazine and Isoxaflutole in Corn Using High-Performance Liquid Chromatography-Tandem Mass Spectrometry.

Isoxaflutole and atrazine are representative pesticides for weed control in corn fields. Formulations containing these two pesticides have been registered in China, and their residues may threaten food safety and human health. In this study, a method for simultaneous determination of isoxaflutole, atrazine, and their metabolites in fresh corn, corn kernels, and corn straw was established based on modified QuEChERS pre-treatment and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The linearity of seven compounds was good (R2 ≥ 0.9912), and the matrix effect was 48.5-77.1%. At four spiked levels of 0.01, 0.02, 0.05, and 0.5 mg kg-1, all compounds' average recovery was 76% to 116%, with relative standard deviation (RSD) less than 18.9%. Field experiments were conducted in Liaoning, Heilongjiang, Inner Mongolia, Shanxi, Beijing, and Yunnan provinces to study the terminal residues. The terminal residues of all compounds were below the LOQ (0.01 mg kg-1) in fresh corn and corn kernels, and atrazine residues in corn straw ranged from <0.05 mg kg-1 to 0.17 mg kg-1. Finally, a dietary risk assessment was conducted based on residues from field trials, food consumption, and acceptable daily intake (ADI). For all populations, the chronic dietary risk probability (RQc) of atrazine was between 0.0185% and 0.0739%, while that of isoxaflutole was 0.0074-0.0296%, much lower than 100%. The results may provide scientific guidance for using isoxaflutole and atrazine in corn field ecosystems.

Genomic insight into the scale specialization of the biological control agent Novius pumilus (Weise, 1892).

BACKGROUND: Members of the genus Novius Mulsant, 1846 (= Rodolia Mulsant, 1850) (Coleoptera, Coccinellidae), play important roles in the biological control of cotton cushion scale pests, especially those belonging to Icerya. Since the best-known species, the vedalia beetle Novius cardinalis (Mulsant, 1850) was introduced into California from Australia, more than a century of successful use in classical biological control, some species of Novius have begun to exhibit some field adaptations to novel but related prey species. Despite their economic importance, relatively little is known about the underlying genetic adaptations associated with their feeding habits. Knowledge of the genome sequence of Novius is a major step towards further understanding its biology and potential applications in pest control. RESULTS: We report the first high-quality genome sequence for Novius pumilus (Weise, 1892), a representative specialist of Novius. Computational Analysis of gene Family Evolution (CAFE) analysis showed that several orthogroups encoding chemosensors, digestive, and immunity-related enzymes were significantly expanded (P < 0.05) in N. pumilus compared to the published genomes of other four ladybirds. Furthermore, some of these orthogroups were under significant positive selection pressure (P < 0.05). Notably, transcriptome profiling demonstrated that many genes among the significantly expanded and positively selected orthogroups, as well as genes related to detoxification were differentially expressed, when N. pumilus feeding on the nature prey Icerya compared with the no feeding set. We speculate that these genes are vital in the Icerya adaptation of Novius species. CONCLUSIONS: We report the first Novius genome thus far. In addition, we provide comprehensive transcriptomic resources for N. pumilus. The results from this study may be helpful for understanding the association of the evolution of genes related to chemosensing, digestion, detoxification and immunity with the prey adaptation of insect predators. This will provide a reference for future research and utilization of Novius in biological control programs. Moreover, understanding the possible molecular mechanisms of prey adaptation also inform mass rearing of N. pumilus and other Novius, which may benefit pest control.

Flavobacterium proteolyticum sp. nov., isolated from aquaculture water.

A novel aerobic, yellow, and rod-shaped bacterial isolate, designated as 1Y8AT, was isolated from aquaculture water sampled in Jiangmen, Guangdong province, P. R. China. Here, the taxonomic position of strain 1Y8AT was conducted based on phenotypic, genomic, and chemotaxonomic characteristics. Strain 1Y8AT was observed to grow at 10-37 °C (optimum 28 °C), at pH 6.0-9.0 (optimum 7.0) and in 0-2% NaCl (optimum 1%, w/v). The 16S rRNA gene-based analysis showed that strain 1Y8AT was closely related to "Flavobacterium sasangense" YC6274T (99.3%), Flavobacterium aquaticum JC164T (98.4%), Flavobacterium cucumis R2A45-3T (98.0%), Flavobacterium celericrescens TWA-26T (98.0%), and Flavobacterium cheniae NJ-26T (97.2%). The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain 1Y8AT and reference strains above were far below the recognized thresholds of 70% dDDH and 95-96% ANI for species definition, implying that the strain represents a novel genospecies. The phylogenomic analysis indicated that strain 1Y8AT formed an independent branch distinct from known species. The major cellular fatty acids of strain 1Y8AT were iso-C15:0, iso-C15:1 G and C15:0; the polar lipids comprised phosphatidylethanolamine, glycolipid, and two lipids; the respiratory quinone was MK-6. The G + C content of genomic DNA was 32.5%. Based on the genotypic and phenotypic characteristics such as the utilization of D-glucose and casein hydrolysis, strain 1Y8AT is concluded to represent a novel species of the genus Flavobacterium, for which the name Flavobacterium proteolyticum sp. nov. is proposed. The type strain of the species is 1Y8AT (= GDMCC 1.1933T = KACC 22081T).

Ideonella alba sp. nov. and Ideonella aquatica sp. nov. isolated from an aquaculture farm.

The three novel bacterial strains designated as 3Y2T, 4Y16 and 4Y11T were isolated from an aquaculture farm and characterized using a polyphasic taxonomic approach. These strains were determined to be catalase- and oxidase-positive and to hydrolyze gelatin and aesculin. The results of 16S rRNA gene-based phylogenetic analysis indicated that the three strains were related to members of the genus Ideonella. The phylogenomic results further indicated that the three strains formed two independent branches distinct from reference type strains within this genus. The digital DNA-DNA hybridization (dDDH), average nucleotide identity (ANI) and average amino acid identity (AAI) values between the three strains and their relatives were far below the thresholds of 70 % dDDH, 95-96 % ANI and 95 % AAI for species definition, respectively, indicating that the three strains represent two novel genospecies. The results of chemotaxonomic characterization indicated that the major cellular fatty acids of the three strains were summed feature 3 (C16 : 1ω6c and/or C16 : 1 ω7c) and C16 : 0; the common main polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol; the respiratory quinone was ubiquinone-8. The genomic DNA G+C contents of the three strains were 70.2, 70.1 and 69.7%, respectively. On the basis of the different genotypes and distinctive phenotypes such as the phosphatidylcholine and glycolipid only in 3Y2T and the utilization of malic acid and trisodium citrate only in 4Y11T, strains 3Y2T and 4Y11T are concluded to represent two novel species of the genus Ideonella, for which the names Ideonella alba sp. nov. (type strain 3Y2T = GDMCC 1.2584T = KCTC 82813T) and Ideonella aquatica sp. nov. (type strain 4Y11T = GDMCC 1.1935T = JCM 34285T) are proposed.

Human health risk-based soil environmental criteria (SEC) for park soil in Beijing, China.

Urban parks are important places that allow urban residents to experience nature but are also associated with the risk of exposure to contaminated soil. Therefore, it is necessary to establish appropriate soil environment criteria (SEC) to manage park soil quality. Studies on the demographic characteristics and behavioral patterns of urban park visitors are helpful for the selection of sensitive receptors and the determination of parameters in the establishment of SEC. This study explored the park visitors' demographic characteristics and behavioral patterns, and applied the results to derive SEC. Eighty-six parks in Beijing were selected, and mobile phone data were obtained to analysis the demographic characteristics and residence time of the visitors. Kruskal-Wallis test, kernel density estimation and random forest model were used for data analysis. The CLEA model was used to derive SEC. The results showed that the demographic characteristics and behavioral patterns of visitors in different types of parks were quite different. Parks were mostly used by males and visitors aged 31-45. Most visitors stayed in the park for 1-2 h, and the distance from a given visitor's home to the park was the most important factor affecting stay time. Then, several parameters such as the parameters related to the receptors and occupation period were optimized, and the SEC of sensitive parks and non-sensitive parks were derived. Exposure frequency may be the main reason for the difference of SEC between the two types of parks. The SECs of sensitive parks were higher than the soil screening values (SSVs) for class 1 land in GB36600-2018, indicating that the current SSVs for some parks may be too conservative. This study provides a reference for the formulation and revision of soil environmental standards for park land, and suggests strengthening research on human behavioral patterns.

Ruegeria alba sp. nov., Isolated from a Tidal Flat Sediment.

A novel Gram-staining-negative, aerobic, rod-shaped, and white-colored bacterium designated as 1NDH52CT was isolated from a tidal flat sediment and its taxonomic position was determined using a polyphasic taxonomic approach. The microorganism was found to grow at 10-37 °C, pH 6.0-9.0, and in the presence of 0-2% (w/v) NaCl, and to hydrolyze gelatin and aesculin. The major cellular fatty acid of strain 1NDH52CT was summed feature 8 (C19:1 ω7c and/or C18:1 ω6c); the polar lipids comprised diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, an aminolipid, and a lipid; the respiratory quinone was ubiquinone-10. The 16S rRNA gene-based phylogenetic analysis showed that strain 1NDH52CT was closely related to members of the genus Ruegeria with the identity of 98.2% to the type strain Ruegeria pomeroyi DSM 15711T. The genome DNA G + C content of strain 1NDH52CT was 63.6%. The phylogenomic analysis indicated that strain 1NDH52CT formed an independent branch distinct from reference type strains of species within this genus. Digital DNA-DNA hybridization and average nucleotide identity values between strain 1NDH52CT and reference strains were, respectively, 19.1-41.5% and 78.3-91.3%, which are far below the thresholds of 70% and 95-96% for species definition, respectively, indicating that strain 1NDH52CT represents a novel genospecies of the genus Ruegeria. Based on phenotypic and genotypic data, strain 1NDH52CT is concluded to represent a novel species of the genus Ruegeria, for which the name Ruegeria alba sp. nov., is proposed. The type strain of the species is 1NDH52CT (= GDMCC 1.2382T = KCTC 82664T).

Horizontally acquired antibacterial genes associated with adaptive radiation of ladybird beetles.

BACKGROUND: Horizontal gene transfer (HGT) has been documented in many herbivorous insects, conferring the ability to digest plant material and promoting their remarkable ecological diversification. Previous reports suggest HGT of antibacterial enzymes may have contributed to the insect immune response and limit bacterial growth. Carnivorous insects also display many evolutionary successful lineages, but in contrast to the plant feeders, the potential role of HGTs has been less well-studied. RESULTS: Using genomic and transcriptomic data from 38 species of ladybird beetles, we identified a set of bacterial cell wall hydrolase (cwh) genes acquired by this group of beetles. Infection with Bacillus subtilis led to upregulated expression of these ladybird cwh genes, and their recombinantly produced proteins limited bacterial proliferation. Moreover, RNAi-mediated cwh knockdown led to downregulation of other antibacterial genes, indicating a role in antibacterial immune defense. cwh genes are rare in eukaryotes, but have been maintained in all tested Coccinellinae species, suggesting that this putative immune-related HGT event played a role in the evolution of this speciose subfamily of predominant predatory ladybirds. CONCLUSION: Our work demonstrates that, in a manner analogous to HGT-facilitated plant feeding, enhanced immunity through HGT might have played a key role in the prey adaptation and niche expansion that promoted the diversification of carnivorous beetle lineages. We believe that this represents the first example of immune-related HGT in carnivorous insects with an association with a subsequent successful species radiation.

Analysis of changes in population's cross-city travel patterns in the pre- and post-pandemic era: A case study of China.

The coronavirus disease (COVID-19) outbreak has immensely changed people's travel behaviour. The changes in travel behaviour have had a huge impact on different industries, such as consumption, entertainment, commerce, office, and education. This study investigates the impact of COVID-19 on population travel patterns from three aspects: total trips, travel recovery degree, and travel distance. The result indicates that COVID-19 has reduced the total number of cross-city trips and flexible non-work travel; in the post-pandemic era, cross-city travel is mainly short-distance (distance <100 km). This study has significant policymaking implications for governments in countries where the population shares a similar change in travel behaviour.

Inhella proteolytica sp. nov. and Inhella gelatinilytica sp. nov., two novel species of the genus Inhella isolated from aquaculture water.

The two novel bacterial strains designated 1Y17T and 4Y10T from aquaculture water were characterized using a polyphasic taxonomic approach. Phylogenetic analysis of 16S rRNA gene sequences revealed that strains 1Y17T and 4Y10T belonged to the genus Inhella and were close to Inhella crocodyli CCP-18T, Inhella inkyongensis IMCC1713T and Inhella fonticola TNR-25T. Strains 1Y17T and 4Y10T shared 98.6% identity with each other and less than 99.0% identity with their relatives above. The phylogenomic analysis indicated that the two strains formed two independent branches distinct from their relatives. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between the two strains were 21.3 and 80.9% below the two thresholds of 70% dDDH and 95-96% ANI for species definition; those between the two novel strains and their relatives were far below thresholds for species definition, implying that they represent two novel genospecies. The predominant fatty acids of the two strains were summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) and C16:0; the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol; the major quinone and polyamine were Q-8 and putrescine. Their genomic DNA G + C contents were 69.3 and 65.0%. The two novel strains can produce poly-ß-hydroxybutyrate, matching with the presence of the three synthetic related genes of the phaC-phaA-phaB in their genomes. Based on the genotypic and phenotypic characteristics such as aesculin and gelatin hydrolysis, strains 1Y17T and 4Y10T are concluded to represent two novel species of the genus Inhella, for which the names Inhella proteolytica sp. nov. (type strain 1Y17T = GDMCC 1.1830T = KACC 21948T) and Inhella gelatinilytica sp. (type strain 4Y10T = GDMCC 1.1829T = KCTC 82338T) are proposed.

Croceicoccus gelatinilyticus sp. nov., isolated from a tidal flat sediment.

A novel Gram-staining-negative and short-rod-shaped bacterial strain designated as 1NDH52T was isolated from a tidal flat sediment and characterized using a polyphasic taxonomic approach. The predominant cellular fatty acids of strain 1NDH52T were summed feature 8 (C18:1 ω7c and/or C18:1 ω6c) and C14:0 2-OH; the major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid; the major respiratory quinone was Q-10. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 1NDH52T was closely related to type strains Croceicoccus sediminis S2-4-2 T (98.9%), Croceicoccus bisphenolivorans H4T (98.9%) and Croceicoccus pelagius Ery9T (98.7%). Phylogenomic analysis indicated that strain 1NDH52T formed an independent branch distinct from all type strains of this genus. The overall genome related indices including the digital DNA-DNA hybridization values, average nucleotide identities and average amino acid identities between strain 1NDH52T and the three close relatives above indicated that strain 1NDH52T should represent a novel genospecies. The genomic DNA G + C content was 62.6%. Strain 1NDH52T could produce carotenoids and its genome contained the complete carotenoids biosynthetic gene cluster. Based on the phenotypic and genotypic characteristics, strain 1NDH52T is concluded to represent a novel species of the genus Croceicoccus, for which the name Croceicoccus gelatinilyticus sp. nov., is proposed. The type strain of the species is 1NDH52T (= GDMCC 1.2381 T = KCTC 82668 T).

Salipiger mangrovisoli sp. nov., isolated from mangrove soil and the proposal for the reclassification of Paraphaeobacter pallidus as Salipiger pallidus comb. nov.

A novel Gram-stain-negative, aerobic and rod-shaped bacterial strain designated as 6D45AT was isolated from mangrove soil and characterized using a polyphasic taxonomic approach. Strain 6D45AT was found to grow at 10-37 °C (optimum, 28 °C), at pH 6.0-9.0 (optimum, 7.0) and in 0-5 % (w/v) NaCl (optimum, 2%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 6D45AT fell into the genus Salipiger and shared 99.1 % identity with the closest type strain Salipiger pacificus CGMCC 1.3455T and less than 97.2 % identity with other type strains of this genus. The 34.8 % digital DNA-DNA hybridization (dDDH) and 88.3 % average nucleotide identity (ANI) values between strain 6D45AT and the closest relative above were well below recognized thresholds of 70 % DDH and 95-96 % ANI for species definition, implying that strain 6D45AT should represent a novel genospecies. The phylogenomic analysis indicated that strain 6D45AT formed an independent branch distinct from reference strains. The predominant cellular fatty acid of strain 6D45AT was summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c, 66.9 %); the polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids, two unidentified glycolipids and an unknown lipid; the respiratory quinone was Q-10. The genomic DNA G+C content was 66.5 mol %. Based on the phenotypic and genotypic characteristics, strain 6D45AT is concluded to represent a novel species of the genus Salipiger, for which the name Salipiger mangrovisoli sp. nov., is proposed. The type strain of the species is 6D45AT (=GDMCC 1.1960T=KCTC 82334T). We also propose the reclassification of Paraphaeobacter pallidus as Salipiger pallidus comb. nov. and 'Pelagibaca abyssi' as a species of the genus Salipiger.

Chitinilyticum piscinae sp. nov., isolated from aquaculture water.

A novel Gram-stain-negative and rod-shaped bacterial strain, designated as 4Y14T, was isolated from aquaculture water and characterized by using a polyphasic taxonomic approach. Strain 4Y14T was found to grow at 10-40 °C (optimum, 28 °C), at pH 7.0-9.0 (optimum, 7.0-8.0) and with 0-2 % NaCl (optimum, 1 %, w/v). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 4Y14T belonged to the genus Chitinilyticum with high levels of similarity to Chitinilyticum litopenaei c1T (97.8 %) and Chitinilyticum aquatile c14T (97.2 %). Phylogenomic analysis indicated that strain 4Y14T formed an independent branch distinct from the two type strains above. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain 4Y14T and the two type strains were, respectively, 25.3 and 25.0 %, and 81.2 and 80.3 %, which were well below the thresholds of 70 % DDH and 95-96 % ANI for species definition, implying that strain 4Y14T should represent a novel genospecies. The predominant cellular fatty acids of strain 4Y14T were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and iso-C16 : 0; the major polar lipids were diphosphatidylglycerol, phosphatidylcholine and phosphatidylethanolamine; and the sole respiratory quinone was Q-8. The genomic DNA G+C content was 60.1 mol%. Based on the phenotypic and genotypic analyses, strain 4Y14T is concluded to represent a novel species of the genus Chitinilyticum, for which the name Chitinilyticum piscinae sp. nov. is proposed. The type strain of the species is 4Y14T (=GDMCC 1.1934T=KACC 22080T).

Roseibium litorale sp. nov., isolated from a tidal flat sediment and proposal for the reclassification of Labrenzia polysiphoniae as Roseibium polysiphoniae comb. nov.

A novel Gram-stain-negative, facultatively anaerobic, rod-shaped and non-motile bacterial strain, designated as 4C16AT, was isolated from a tidal flat sediment and characterized by using a polyphasic taxonomic approach. Strain 4C16AT was found to grow at 10-40 °C (optimum, 28 °C), at pH 5.0-10.0 (optimum, pH 6.0-7.0) and in 0-6 % (w/v) NaCl (optimum, 1 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 4C16AT fell into the genus Roseibium, and shared the highest identity of 98.9 % with the closest type strain Roseibium suaedae KACC 13772T and less than 98.0 % identity with other type strains of recognized species within this genus. The phylogenomic analysis indicated that strain 4C16AT formed an independent branch within this genus. The 28.6 % digital DNA-DNA hybridization estimate and 85.0 % average nucleotide identity between strains 4C16AT and R. suaedae KACC 13772T were the highest, but still far below their respective threshold for species definition, implying that strain 4C16AT should represent a novel genospecies. The predominant cellular fatty acid was summed feature 8; the polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylmonomethylethanolamine; the respiratory quinones were Q-9 and Q-10. The genomic DNA G+C content was 59.8mol %. Based on phylogenetic analyses and phenotypic and chemotaxonomic characteristics, strain 4C16AT is concluded to represent a novel species of the genus Roseibium, for which the name Roseibium litorale sp. nov. is proposed. The type strain of the species is 4C16AT (=GDMCC 1.1932T=KACC 22078T). We also propose the reclassification of Labrenzia polysiphoniae as Roseibium polysiphoniae comb. nov. and 'Labrenzia callyspongiae' as Roseibium callyspongiae sp. nov.

Qipengyuania soli sp. nov., Isolated from Mangrove Soil.

A novel Gram-stain-negative, non-motile, and rod-shaped bacterial strain, designated as 6D36T, was isolated from mangrove soil and characterized by using a polyphasic taxonomic approach. Strain 6D36T was found to grow at 10-37 °C (optimum, 28 °C), at pH 6.0-9.0 (optimum, 7.0) and in 0-8% (w/v) NaCl (optimum, 3%). The predominant cellular fatty acids of strain 6D36T were summed feature 8 (C19:1 ω7c and/or C18:1 ω6c) and C17:1 ω6c; the major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, and sphingoglycolipid; the sole respiratory quinone was Q-10. The phylogenetic analysis based on 16S rRNA gene sequences showed that strain 6D36T fell into the genus Qipengyuania and was closely related to "Erythrobacter mangrovi" MCCC 1K03690T (98.5%), Qipengyuania citrea CGMCC 1.8703T (97.6%), and Qipengyuania pelagi JCM 17468T (97.4%). The phylogenomic analysis indicated that strain 6D36T formed an independent branch distinct from reference-type strains of species within this genus. The digital DNA-DNA hybridization and average nucleotide identity values between strain 6D36T and the three type strains above were, respectively, 20.2-21.3% and 79.5-81.5%, of which were far below their respective threshold for species definition, implying that the strain represents a novel genospecies. The genomic DNA G + C content was 63.3%. Based on phenotypic and genotypic characteristics, strain 6D36T is concluded to represent a novel species of the genus Qipengyuania, for which the name Qipengyuania soli sp. nov., is proposed. The type strain of the species is 6D36T (= GDMCC 1.1977T = KCTC 82333T).

Spread of COVID-19 in China: analysis from a city-based epidemic and mobility model.

Understanding the processes and mechanisms of the spatial spread of epidemics is essential for making reasonable judgments on the development trends of epidemics and for adopting effective containment measures. Using multi-agent network technology and big data on population migration, this paper constructed a city-based epidemic and mobility model (CEMM) to stimulate the spatiotemporal of COVID-19. Compared with traditional models, this model is characterized by an urban network perspective and emphasizes the important role of intercity population mobility and high-speed transportation networks. The results show that the model could simulate the inter-city spread of COVID-19 at the early stage in China with high precision. Through scenario simulation, the paper quantitatively evaluated the effect of control measures "city lockdown" and "decreasing population mobility" on containing the spatial spread of the COVID-19 epidemic. According to the simulation, the total number of infectious cases in China would have climbed to 138,824 on February 2020, or 4.46 times the real number, if neither of the measures had been implemented. Overall, the containment effect of the lockdown of cities in Hubei was greater than that of decreasing intercity population mobility, and the effect of city lockdowns was more sensitive to timing relative to decreasing population mobility.

Changes in life history traits and transcriptional regulation of Coccinellini ladybirds in using alternative prey.

BACKGROUND: Ladybird beetles (Coleoptera, Coccinellidae) are highly diverse in their feeding habits. Most of them are specialist feeders, while some can have a broad spectrum of prey. As a representative group of generalists, the tribe Coccinellini includes many aphidophagous species, but members of this tribe also feed on other hemipterous insects including coccids, psyllids and whiteflies. As a result, several species are effective biological control agents or invasive species with serious non-target effects. Despite their economic importance, relatively little is known about how they adapt to new prey. RESULTS: In this study, comparisons of the life history traits and transcriptomes of ladybirds fed initial (aphids) and alternative prey (mealybugs) were performed in three Coccinellini species. The use of alternative prey greatly decreased performance, implied by the significantly prolonged development time and decreased survival rate and adult weight. Prey shifts resulted in a set of differentially expressed genes encoding chemosensory proteins and digestive and detoxifying enzymes. CONCLUSIONS: Our results suggest that these generalists do not perform well when they use alternative prey as the sole nutrition source. Although their capacity for predation might have created an opportunity to use varied prey, they must adapt to physiological obstacles including chemosensing, digestion and detoxification in response to a prey shift. These findings challenge the effect of Coccinellini predators on the biological control of non-aphid pests and suggest the possibility of non-target attacks by so-called specialists.