Repellency and toxicity of a CO2-derived cedarwood oil on hard tick species (Ixodidae).

The repellency and toxicity of a CO2-derived cedarwood oil (CWO) was evaluated against actively questing unfed nymphs of four species of hard ticks: Amblyomma americanum (L.), Dermacentor variabilis (Say), Ixodes scapularis Say, and Rhipicephalus sanguineus (Latreille). Using a vertical climb bioassay for repellency, nymphs of these species avoided a CWO-treated filter paper in proportional responses to treatment concentrations. At 60 min of exposure, I. scapularis nymphs were most sensitive with 50% repellency concentration (RC50) of 19.8 µg cm-2, compared with RC50 of 30.8, 83.8 and 89.6 µg cm-2 for R. sanguineus, D. variabilis and A. americanum, respectively. Bioassays determined the lethal concentration for 50% (LC50) and 90% (LC90) mortality of nymphs exposed to CWO in treated vials after 24- and 48-h exposure. After 24 h exposure, the LC50 values were 1.25, 3.45 and 1.42 µg cm-2 and LC90 values were 2.39, 7.59 and 4.14 µg cm-2 for D. variabilis, I. scapularis and R. sanguineus, respectively, but had minimal effect on A. americanum. After 48 h exposure, the LC50 values were 4.14, 0.78, 0.79 and 0.52 µg cm-2, and LC90 values were 8.06, 1.48, 1.54 and 1.22 µg cm-2 for A. americanum, D. variabilis, I. scapularis and R. sanguineus, respectively. The repellency of CWO on tick species decreased with time. The repellency and toxicity bioassays demonstrated concentration-dependent responses of tick nymphs to the oil, indicating the potential of the CO2-derived cedarwood oil be developed as an eco-friendly repellent and/or acaricide.

Methylobacterium segetis sp. nov., a novel member of the family Methylobacteriaceae isolated from soil on Jeju Island.

A bacterial strain, 17J42-1T, was isolated from a soil sample collected on Jeju Island, Republic of Korea. Colonies grown on R2A agar were pink in color, and cells were Gram-stain negative, short and rod-shaped. Analysis of 16S rRNA gene sequences identified this strain as a member of the genus Methylobacterium in the family Methylobacteriaceae, with high levels of 16S rRNA sequence similarity shared with Methylobacterium oxalidis 35aT (98.6%), Methylobacterium jeotgali S2R03-9T (97.5%), and Methylobacterium soli YIM 48816T (97.3%). Cells grew at 15-35 °C, pH 5-9, and in the presence of 0-1.0% NaCl. The genomic G + C content was 70.2 mol% based on the whole genome analysis. The predominant respiratory quinone was ubiquinone Q-10, the major fatty acid was C18:1ω7c (85.3%), and the major polar lipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. The phenotypic and chemotaxonomic data support the affiliation of strain 17J42-1T with the genus Methylobacterium. However, the DNA-DNA relatedness between the isolate and its closest phylogenetic neighbors was lower than 38%. The OrthoANI and dDDH values between strain 17J42-1T and the closest type strain Methylobacterium oxalidis NBRC 107715T were calculated to be 85.9% and 30.6%, respectively. The results of 16S rRNA gene sequence similarity analysis, DNA-DNA hybridization analysis, and the observed differentiating phenotypic properties from other closely related taxa clearly indicate that strain 17J42-1T represents a novel species in the genus Methylobacterium, for which the name Methylobacterium segetis sp. nov. is proposed. The type strain is 17J42-1T (= KCTC 62267T = JCM 33059T).

Iturinic Lipopeptide Diversity in the Bacillus subtilis Species Group - Important Antifungals for Plant Disease Biocontrol Applications.

Iturins and closely related lipopeptides constitute a family of antifungal compounds known as iturinic lipopeptides that are produced by species in the Bacillus subtilis group. The compounds that comprise the family are: iturin, bacillomycin D, bacillomycin F, bacillomycin L, mycosubtilin, and mojavensin. These lipopeptides are prominent in many Bacillus strains that have been commercialized as biological control agents against fungal plant pathogens and as plant growth promoters. The compounds are cyclic heptapeptides with a variable length alkyl sidechain, which confers surface activity properties resulting in an affinity for fungal membranes. Above a certain concentration, enough molecules enter the fungal cell membrane to create a pore in the cell wall, which leads to loss of cell contents and cell death. This study identified 330 iturinic lipopeptide clusters in publicly available genomes from the B. subtilis species group. The clusters were subsequently assigned into distinguishable types on the basis of their unique amino acid sequences and then verified by HPLC MS/MS analysis. The results show some lipopeptides are only produced by one species, whereas certain others can produce up to three. In addition, four species previously not known to produce iturinic lipopeptides were identified. The distribution of these compounds among the B. subtilis group species suggests that they play an important role in their speciation and evolution.

Emticicia agri sp. nov., a novel member of the family Cytophagaceae.

A bacterial strain, 17J42-9T, was isolated from a soil sample collected on Jeju Island, Republic of Korea. Cells were observed to be Gram-stain negative and rod-shaped. Colonies were observed to be orange in colour on R2A agar. Analysis of 16S rRNA gene sequences showed that high levels of 16S rRNA sequence similarity were shared between 17J42-9T and Emticicia fontis IMCC1731T (98.2 %), Emticicia ginsengisoliGsoil 085T (98.2 %) and Emticicia soli ZZ-4T (97.8 %). Growth of strain 17J42-9T was observed at 10-37 °C, pH 6.0-8.5 and in the presence of 0-0.5 % NaCl. The genomic G+C content was calculated to be 38.6 mol%. The predominant respiratory quinone of the isolate was found to be MK-7; the major fatty acids were identified as summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) (34.1 %), C15 : 0iso (23.4 %) and C17 : 0iso 3-OH (10.8 %). The major polar lipids were found to be phosphatidylethanolamine, two unidentified aminolipids and an unidentified lipid. The phenotypic and chemotaxonomic data support the affiliation of strain 17J42-9T with the genus Emticicia. However, the DNA-DNA relatedness between the isolate and its closest phylogenetic neighbours was lower than 46 %. The results of 16S rRNA gene sequence similarity analysis, DNA-DNA hybridization analysis and the observed differentiating phenotypic properties from other closely related taxa clearly indicate that strain 17J42-9T represents a novel species in the genus Emticicia, for which the name Emticiciaagri sp. nov. is proposed. The type strain is 17J42-9T (=KCTC 62270T=JCM 33056T).

Mucilaginibacter terrigena sp. nov. sp., A Novel Member of the Family Sphingobacteriaceae.

A bacterial strain, 17JY9-4T, was isolated from a soil sample collected on Jeju Island, South Korea. Colonies grown on R2A agar are pale pink in color, and cells are Gram-stain negative, short, and rod-shaped. Analysis of 16S rRNA gene sequences identified this strain as a member of the genus Mucilaginibacter in the family Sphingobacteriaceae, with high levels of 16S rRNA sequence similarity shared with Mucilaginibacter lutimaris BR-3T (98.0%), Mucilaginibacter rigui WPCB133T (98.0%), Mucilaginibacter phyllosphaerae PP-F2F-G21T (97.0%), Mucilaginibacter amnicola TAPP7T (96.8%), and Mucilaginibacter soli R9-65T (96.7%). Growth of strain 17JY9-4T occurs at 10-30 °C, pH 6-8, and in the presence of 0-1.0% NaCl. The genomic G+C content is 44.38 mol%. The predominant respiratory quinone of the isolate is MK-7; the major fatty acids are summed feature 3 (C16:1ω7c/C16:1ω6c) (39.7%), iso-C15:0 (22.8%), iso-C17:0 3-OH (7.8%), and C16:0 (7.7%); and the major polar lipid is phosphatidylethanolamine. The phenotypic and chemotaxonomic data support the placement of strain 17JY9-4T within the genus Mucilaginibacter. However, the DNA-DNA relatedness between the isolate and M. rigui, M. lutimaris, M. phyllosphaerae, M. amnicola, and M. soli were 44.3 ± 3.0%, 38.6 ± 3.7%, 23.2 ± 2.9%, 21.9 ± 3.1%, and 18.6 ± 3.7%, respectively. The results of 16S rRNA gene sequence similarity analysis, DNA-DNA hybridization analysis, and the observed differentiating phenotypic properties from other closely related taxa clearly indicate that strain 17JY9-4T represents a novel species in the genus Mucilaginibacter, for which the name Mucilaginibacter terrigena sp. nov. is proposed. The type strain is 17JY9-4T (= KCTC 62294T = JCM 33049T).

Honeysuckle essential oil as a potential source of ecofriendly larvicides for mosquito control.

BACKGROUND: Some plant essential oils have insecticidal properties against mosquitoes and can be harnessed as ecofriendly tools for mosquito control. We conducted bioassays to determine the toxicity of Italian honeysuckle (Lonicera caprifolium) essential oil and its fractions against larvae of the yellow fever mosquito, Aedes aegypti. RESULTS: Sixteen constituents were identified in honeysuckle essential oil compared to 15, 15, 15, and 11 constituents in fractions A, B, C, and E, respectively. The chemical constituents for fraction D were not determined due to lack of enough fraction sample. The two major constituents identified were patchouli alcohol (29.3%) and 6-acetyl-1,1,2,4,4,7-hexamethyltetralin (20.6%) in whole essential oil, alpha-bulnesene (27.6%) and 6-acetyl-1,1,2,4,4,7-hexamethyltetralin (23.2%) in fraction A, unknown chemical (47.3%) and diethyl phthalate (19.5%) in fraction B, unknown chemical (38.3%) and diethyl phthalate (23.2%) in fraction C, and patchouli alcohol (58.7%) and diethyl phthalate (20.5%) in fraction E. The LC50 for whole essential oil was 34.4 ppm and significantly higher than 20.6, 19.7, 18.6, and 17.7 ppm for fractions B, C, D, and E, respectively. In contrast, fraction A was inactive. At 50 ppm, all individual constituents tested were less toxic than the whole essential oil with exception of patchouli alcohol, which caused 100% mortality. CONCLUSION: These findings suggest that patchouli alcohol is one of the chemical constituents responsible for bioactivity of honeysuckle essential oil and some of its fractions. The findings also demonstrate that honey suckle essential oil and its fractions can be exploited as a source of ecofriendly larvicides for mosquito control. Published 2019. This article is a U.S. Government work and is in the public domain in the USA.

Peptidoglycan Recognition Proteins (PGRPs) Modulates Mosquito Resistance to Fungal Entomopathogens in a Fungal-Strain Specific Manner.

Fungal entomopathogens are potential tools for the control of mosquito vectors that transmit infectious agents that cause disease in humans and animals. During the infection process, effective recognition of the invading fungi by the mosquito, is a crucial step in mounting an appropriate anti-fungal response. In this study, we investigated the role of peptidoglycan recognition receptors (PGRPs) in host resistance to fungal entomopathogens at the early stages of infection. Our study identified the induction of PGRP-LA, -LB, -LD, -LE, and -S1 during infection with two different fungal entomopathogenic strains. Furthermore, our data shows temporal differences in PGRP elicitation, with most PGRPs displaying significant upregulation at 60 h post-infection. Depletion of certain PGRPs via RNAi silencing resulted in a significant increase in fungal proliferation and a reduction in mosquito survival that was fungal strain-specific. Our data indicates that PGRPs play an important role in the antifungal response and expands our understanding of the factors that determine host susceptibility to fungal entomopathogens.

Host blood-meal source has a strong impact on gut microbiota of Aedes aegypti.

Gut microbial communities of mosquitoes can influence vector susceptibility to pathogens, yet the factors that govern their composition remain poorly understood. We investigated the impact of host blood-meal source on gut microbiota of Aedes aegypti L. Adult mosquitoes were fed on human, rabbit or chicken blood and their gut microbiota compared to those of sugar-fed and newly emerged adults. Microbial diversity was significantly reduced in blood-fed and sugar-fed mosquitoes but was restored to the levels of newly emerged adults at 7-days post-blood meal. Microbial composition was strongly influenced by host blood-meal source. Leucobacter spp., Chryseobacterium spp., Elizabethkingia spp. and Serratia spp. were characteristic of newly emerged adults and adults fed on chicken, rabbit and human blood, respectively. Sugar-fed mosquitoes had higher abundance of Pseudomonas spp. and unclassified Acetobacteraceae. Shifts in gut microbial communities in response to host blood-meal source may fundamentally impact pathogen transmission given the well-documented link between specific bacterial taxa and vector susceptibility to a variety of mosquito-borne pathogens and may be a key determinant of individual and population variation in vector competence.

The Aedes aegypti IMD pathway is a critical component of the mosquito antifungal immune response.

Successful infection of the insect body by entomopathogenic fungi is the result of complex molecular interactions between the host and the invading pathogenic fungi. The mosquito antifungal response is multifaceted and is regulated in part by the Toll and Jak-STAT pathways. Here, we assessed the role of the IMD pathway in the mosquito Ae. aegypti antifungal immune response when challenged with one of two entomopathogenic fungi, Beauveria bassiana and Isaria javanica. IMD pathway components of the mosquito immune system were elicited in response to infection with both entomopathogenic fungi, primarily in the fat body of mosquitoes. Furthermore, we observed induction of antimicrobial peptides that in turn appear to be tissue and fungal strain-specific. IMD pathway impairment by RNAi gene silencing resulted in higher fungal proliferation and reduction in survival of fungi-infected mosquitoes. Collectively, these data indicates that the IMD pathway plays a more significant role in the antifungal immune response than previously recognized.

Bioactivity of Wild Carrot (Daucus carota, Apiaceae) Essential Oil Against Mosquito Larvae.

Invasive alien plants wreak havoc on native ecosystems and using them as a source of biopesticides could improve their management. We examined the toxicity of essential oil of wild carrot (also known as 'Queen Anne's Lace', Daucus carota Linnaeus), an aggressive invader throughout the United States, against Aedes aegypti L., Culex pipiens L., and Culex restuans Theobald larvae. Comparisons were made between essential oil extracted from umbels of local populations of wild carrot versus a commercial brand. Methyl isoeugenol (60.7%) was by far the most abundant constituent in commercial brand oil, whereas α-pinene (33.0%) and ß-pinene (25.8%) were the dominant constituents in essential oil extracted from local wild carrot populations. The commercial brand essential oil was significantly more toxic to Cx. restuans larvae (LC50 = 44.4 ppm) compared with Cx. pipiens (LC50 = 51.0 ppm) and Ae. aegypti (LC50 = 54.5 ppm). Essential oil from local populations of wild carrot was significantly more toxic to both Cx. pipiens (LC50 = 42.9) and Cx. restuans (LC50 = 40.3) larvae compared with Ae. aegypti (LC50 = 64.6 ppm) larvae. Three of the nine tested chemical constituents of wild carrot essential oil (terpinolene, para cymene, and γ-terpinene) were consistently more toxic to larvae of the three mosquito species than the whole essential oil. These findings suggest that exploiting wild carrot essential oil and its chemical constituents as a biopesticide for mosquito control could be used as part of multifaceted approaches for controlling this invasive alien plant species.

Mosquito microbiota cluster by host sampling location.

BACKGROUND: Microbial communities that inhabit the mosquito body play an import role in host biology and may have potential for mosquito control. However, the forces that shape these microbial communities are poorly understood. METHODS: To gain a better understanding of how host location influences the composition and diversity of mosquito microbiota, we performed a survey of microbial communities in mosquito samples collected from six USA states using HiSeq sequencing of the 16S rRNA gene. RESULTS: A total of 284 bacterial operational taxonomic units (OTUs) belonging to 14 phyla were detected in nine mosquito species, with Proteobacteria, Firmicutes and Actinobacteria accounting for 95% of total sequences. OTU richness varied markedly within and between mosquito species. The microbial composition and diversity was heavily influenced by the site of mosquito collection, suggesting that host location plays an important role in shaping the mosquito microbiota. CONCLUSIONS: Variation in microbial composition and diversity between mosquitoes from different locations may have important implications on vector competence and transmission dynamics of mosquito-borne pathogens. Future studies should investigate the environmental factors responsible for these variations and the role of key bacteria characterized in this study on mosquito biology and their potential application in symbiotic control of mosquito-borne diseases.

Strain-specific pathogenicity and subversion of phenoloxidase activity in the mosquito Aedes aegypti by members of the fungal entomopathogenic genus Isaria.

Development of alternative vector control strategies are becoming more pressing given the rapid evolution of insecticide resistance and the rise of vector borne pathogens affecting public health such as dengue, chikungunya and Zika. Fungal-based biopesticides are promising alternatives to synthetic insecticides because they are ecofriendly and are highly effective at infecting insects through contact. This study evaluated the susceptibility of the yellow fever mosquito Ae. aegypti to a range of entomopathogenic fungal strains from the genus Isaria. We observed a diverse variation in the virulence of the Isaria strains tested, with two strains showing high pathogenicity towards adult mosquitoes. Mosquito susceptibility to fungal infection was further corroborated through the molecular quantification of fungal loads and the transcript evaluation of a fungal-specific pathogen recognition molecule in the mosquito body. Moreover, quantitative analysis of transcript abundance coupled with enzymatic assays revealed strain-specific subversion of the melanization cascade, an important immune response component. Our study contributes critical insights for a better understanding of fungal-mosquito interactions.

Marinicella sediminis sp. nov., isolated from marine sediment.

A novel heterotrophic, Gram-stain-negative, aerobic, rod-shaped, pale yellow, non-motile and non-spore-forming bacterium, designated strain F2T, was isolated from marine sediment collected from the Weihai coast, Shandong Province, PR China. Optimal growth occurred at 33 °C (range, 10-37 °C), with 3.0-4.0 % (w/v) NaCl (1.0-8.0 %) and at pH 7.5-8.0 (pH 6.5-9.0). Q-8 was the sole respiratory quinone. The major polar lipids of strain F2T were phosphatidylmonomethylethanolamine, phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids and two unidentified polar lipids. The major cellular fatty acid in strain F2T was iso-C15 : 0. The genomic DNA G+C content of the strain was 48.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that strain F2T is most closely related to Marinicella litoralis JCM 16154T (97.5 %) and Marinicella pacifica sw153T (96.0 %). Based on the results of our polyphasic analysis, we conclude that strain F2T represents a novel species of the genus Marinicella, for which the name Marinicella sediminis sp. nov. is proposed. The type strain of the new species is F2T (=KCTC 42953T=MCCC 1H00149T).

Ovicidal and Larvicidal Effects of Garlic and Asafoetida Essential Oils Against West Nile Virus Vectors.

We examined the chemical composition of garlic and asafoetida essential oils and their individual and combined toxicity against larvae of Culex pipiens Linnaeus and Culex restuans Theobald (Diptera: Culicidae). The effect of the two essential oils on egg hatch was also examined. Ten and 12 compounds, respectively, were identified in garlic and asafoetida essential oils. Allyl disulfide (49.13%) and diallyl trisulfide (31.08%) were the most abundant compounds in garlic essential oil accounting for 80.2% of the total oil. In contrast, (E)-sec-butyl propenyl disulfide (30.03%), (Z)-sec-butyl propenyl disulfide (24.32%), and disulfide, methyl 1-(methylthio)propyl (21.87%) were the most abundant compounds in asafoetida essential oil. Allyl disulfide accounted for 7.38% of the total oil in asafoetida essential oil and was one of only three compounds found in both oils. For both mosquito species, garlic essential oil was more toxic than asafoetida essential oil with Cx. restuans (LC50: garlic = 2.7 ppm; asafoetida = 10.1 ppm) being more sensitive than Cx. pipiens (LC50: garlic = 7.5 ppm; asafoetida = 13.5 ppm). When combined, the two essential oils had antagonistic effects. The majority of Culex egg rafts exposed to garlic (73.1%) or asafoetida (55.8%) essential oils failed to hatch and larvae of the few that did hatch mostly died as first instars. Allyl disulfide exhibited strong ovicidal and larvicidal activity suggesting its important contribution to the overall toxicity of the two essential oils. Thus, garlic and asafoetida essential oils are potent mosquito ovicides and larvicides but if used jointly, they could undermine vector control programs.

Entomopathogenic fungal infection leads to temporospatial modulation of the mosquito immune system.

Alternative methods of mosquito control are needed to tackle the rising burden of mosquito-borne diseases while minimizing the use of synthetic insecticides, which are threatened by the rapid increase in insecticide resistance in mosquito populations. Fungal biopesticides show great promise as potential alternatives because of their ecofriendly nature and ability to infect mosquitoes on contact. Here we describe the temporospatial interactions between the mosquito Aedes aegypti and several entomopathogenic fungi. Fungal infection assays followed by the molecular assessment of infection-responsive genes revealed an intricate interaction between the mosquito immune system and entomopathogenic fungi. We observed contrasting tissue and time-specific differences in the activation of immune signaling pathways and antimicrobial peptide expression. In addition, these antifungal responses appear to vary according to the fungal entomopathogen used in the infection. Enzyme activity-based assays coupled with gene expression analysis of prophenoloxidase genes revealed a reduction in phenoloxidase (PO) activity in mosquitoes infected with the most virulent fungal strains at 3 and 6d post-fungal infection. Moreover, fungal infection led to an increase in midgut microbiota that appear to be attributed in part to reduced midgut reactive oxygen species (ROS) activity. This indicates that the fungal infection has far reaching effects on other microbes naturally associated with mosquitoes. This study also revealed that despite fungal recognition and immune elicitation by the mosquito, it is unable to successfully eliminate the entomopathogenic fungal infection. Our study provides new insights into this intricate multipartite interaction and contributes to a better understanding of mosquito antifungal immunity.

Proposed minimal standards for the use of genome data for the taxonomy of prokaryotes.

Advancement of DNA sequencing technology allows the routine use of genome sequences in the various fields of microbiology. The information held in genome sequences proved to provide objective and reliable means in the taxonomy of prokaryotes. Here, we describe the minimal standards for the quality of genome sequences and how they can be applied for taxonomic purposes.

Comparative Analysis of Gut Microbiota of Culex restuans (Diptera: Culicidae) Females From Different Parents.

The potential for gut microbiota to impede or enhance pathogen transmission is well-documented but the factors that shape this microbiota in mosquito vectors are poorly understood. We characterized and compared the gut microbiota of adult females of Culex restuans (Theobald; Diptera: Culicidae) from different parents. Cx. restuans larvae from nine field-collected egg rafts were reared on a common diet and gut microbiota of newly emerged adult females characterized by MiSeq sequencing of the V4 hypervariable region of the 16S rRNA gene. Bacterial diversity and evenness in individuals from one egg raft were significantly lower compared to those of three of the other eight egg rafts. The gut microbiota of adult females reared from seven of the nine egg rafts clustered together suggesting that individuals from most egg rafts had similar profiles of gut microbiota. These findings suggest that the microbiota of adult females from the same parents do not differ appreciably from the microbiota of adult females from different parents. However, additional studies using mosquitoes separated by geographic distances greater than those studied here and estimating the genetic distances between populations from different egg rafts are needed to provide further insights into the influence of host genetics on gut microbiota. Also worthwhile are studies evaluating how individuals from different egg rafts and harboring different gut microbiota compare in relation to vector competence for different pathogens.

Acinetobacter dijkshoorniae is a later heterotypic synonym of Acinetobacter lactucae.

Acinetobacter lactucae and Acinetobacter dijkshoorniae were recently described as novel species, and both were reported to be closely related to Acinetobacter pittii. Because they were reviewed and published almost concurrently, their descriptions did not include a specific comparison between these two novel species. Genomic data were provided in both initial descriptions, which simplifies the comparisons. Genome comparisons based on in silico DNA-DNA hybridizations, average nucleotide identity and core genome phylogeny of the type strain genomes establish that these strains are conspecific. Based on the rules of priority, A. dijkshoorniae should be reclassified as a later heterotypic synonym of A. lactucae.

Chengkuizengella sediminis gen. nov. sp. nov., isolated from sediment.

A Gram-stain-positive, aerobic, motile, endospore-forming bacterium, designated strain J15A17T, was isolated from sediment of the South China Sea. The strain was oxidase-positive and catalase-negative. Optimal growth occurred at 33 °C, pH 7.5 and in the presence of 3 % (w/v) NaCl. On the basis of 16S rRNA gene sequence analysis, the strain showed closest similarity (92.8 %) to Paenibacillus puldeungensis strain CAU 9324T. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate forms a separate branch within the family Paenibacillaceae, with the genus Cohnella as the most closely related genus. The DNA G+C content of strain J15A17T was 37.4 mol%. The strain contained MK-7 as the sole respiratory quinone; anteiso-C15 : 0 and iso-C16 : 0 were the major cellular fatty acids; and its polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, glycolipid and four unidentified phospholipids. The strain displayed the peptidoglycan type A4α l-Lys-d-Asp in the cell wall. Phylogenetic, physiological, biochemical and morphological differences between strain J15A17T and its closest relatives in the genera Cohnella, Fontibacillus and Paenibacillus suggest that strain J15A17T (=KCTC 33759T=MCCC 1H00137T) represents the type strain of a novel species in a new genus within the family Paenibacillaceae, Chengkuizengella sediminis gen. nov. sp. nov.

Gracilimonas halophila sp. nov., isolated from a marine solar saltern.

A Gram-stain-negative and facultatively anaerobic bacterium, designated WDS2C40T, was isolated from a marine solar saltern in Weihai, China. Cells of strain WDS2C40T were 0.4-0.5 µm wide and 4.0-9.0 µm long, catalase-positive and oxidase-negative. Strain WDS2C40T was tolerant to moderate salt concentrations. Growth occurred at 20-42 °C (optimum, 37-40 °C), at pH 7.0-8.5 (optimum, 7.5-8.0) and with 2-16 % (w/v) NaCl (optimum, 6-8 %). A phylogenetic analysis of the 16S rRNA gene indicated that strain WDS2C40T was a member of the genus Gracilimonas within the family Balneolaceae. The most closely related neighbour was Gracilimonas rosea JCM 18898T (95.92 % similarity). The major respiratory quinone of strain WDS2C40T was menaquinone MK-7, and the dominant fatty acids were iso-C13 : 0, iso-C15 : 0 and summed feature 3. The major polar lipids were diphosphatidylglycerol, one kind of glycolipid and two unidentified phospholipids. The genomic DNA G+C content was 41.7 mol%. Based on this polyphasic taxonomic study, strain WDS2C40T is considered to represent a novel species in the genus Gracilimonas, for which the name Gracilimonas halophila sp. nov. is proposed. The type strain is WDS2C40T (=KCTC 52042T=MCCC 1H00135T).