Lipopeptide C17 Fengycin B Exhibits a Novel Antifungal Mechanism by Triggering Metacaspase-Dependent Apoptosis in Fusarium oxysporum.

Fusarium wilt is a worldwide soil-borne fungal disease caused by Fusarium oxysporum that causes serious damage to agricultural products. Therefore, preventing and treating fusarium wilt is of great significance. In this study, we purified ten single lipopeptide fengycin components from Bacillus subtilis FAJT-4 and found that C17 fengycin B inhibited the growth of F. oxysporum FJAT-31362. We observed early apoptosis hallmarks, including reactive oxygen species accumulation, mitochondrial dysfunction, and phosphatidylserine externalization in C17 fengycin B-treated F. oxysporum cells. Further data showed that C17 fengycin B induces cell apoptosis in a metacaspase-dependent manner. Importantly, we found that the expression of autophagy-related genes in the TOR signaling pathway was significantly upregulated; simultaneously, the accumulation of acidic autophagy vacuoles in F. oxysporum cell indicated that the autophagy pathway was activated during apoptosis induced by C17 fengycin B. Therefore, this study provides new insights into the antifungal mechanism of fengycin.

Antifungal activities of Bacillus velezensis FJAT-52631 and its lipopeptides against anthracnose pathogen Colletotrichum acutatum.

This study was aim at investigating antifungal activities of Bacillus velezensis FJAT-52631 and its lipopeptides against Colletotrichum acutatum ex situ and in situ. The results showed that the strain FJAT-52631 and its crude lipopeptides (10 mg/ml) exhibited strong inhibitory effects on growth of C. acutatum FJAT-30256 with an inhibition rate of 75.3% and an inhibition zone diameter of 17.66 mm, respectively. Both the viable bacterial cultures and lipopeptides of FJAT-52631 could delay the onset of loquat anthracnose by 1 day and lower the incidence of loquat anthracnose in situ. The whole cultures of B. velezensis FJAT-52631 displayed a 50% biocontrol efficacy on loquat anthracnose at the fourth day after inoculation, but the crude lipopeptides not. The average lesion diameter of the whole-culture treated group was 5.62 mm, which was smaller than that of control group (6.81 mm). All the three types of lipopeptides including iturin A, fengycin, and surfactin A secreted from the strain FJAT-52631 exhibited antifungal activities. Among them, surfactin A displayed higher antifungal activity at a concentration of 1.25 mg/mL than other two lipopeptides even if at a concentration of 60 mg/mL. Thus, the results indicated that surfactin A produced by FJAT-52631 played a major role in the biocontrol of the loquat anthracnose. Scanning electron microscopy (SEM) observation revealed the structural deformities in the mycelia of C. acutatum. The above results suggested that the antifungal lipopeptides from B. velezensis FJAT-52631 would be potential in biocontrol against anthracnose disease of loquat caused by C. acutatum.

Effect of FXR agonist GW4064 in the treatment of hilar cholangiocarcinoma in rats.

The study objective was to observe the treatment effect of the farnesoid X receptor (FXR) agonist GW4064 in a rat model of hilar cholangiocarcinoma to explore a new therapeutic target for gene therapy for hilar cholangiocarcinoma. Eighty male Wistar rats were randomly divided into four groups (treatment group, model group, control group and sham operation group, 20 rats in each group). The four groups were fed a standard diet. The treatment group and the model group were injected with a suspension of cholangiocarcinoma QBC939 cells into the hilar bile duct with a microsyringe, the control group was injected with normal saline, and the sham operation group was not injected with anything. A modified tail suspension test (TST) was used to evaluate the vitality of the rats. At 4 weeks, one rat in the treatment group and model group was euthanized, and the changes in the hilar bile duct were recorded. The procedure was repeated at 6 weeks. After 6 weeks, hilar cholangiocarcinoma occurred in the treatment group and model group. Then, the treatment group was injected with GW4064 intraperitoneally at a dose of 50 mg/kg/day. One week after injection, the rats in the four groups were euthanized. Pathological examination confirmed that tumours had formed, and hilar bile duct tissues were taken from the four groups. FXR, Bsep, Ntcp and NF-κB expression in the hilar bile duct was detected by real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. After three weeks, the rats in the treatment group and model group ate less, and their weight was significantly reduced. Six weeks later, hilar cholangiocarcinoma was detected in the treatment group and model group. After treatment with GW4064, the ratios of FXR/GAPDH mRNA, Bsep/GAPDH mRNA, Ntcp/GAPDH mRNA and NF-κBp65/GAPDH mRNA were significantly different among the four groups. Under a light microscope, FXR protein reacted with anti-FXR antibody, Bsep protein reacted with anti-Bsep antibody, Ntcp protein reacted with anti-Ntcp antibody and NF-κBp65 protein reacted with anti-NF-κBp65 antibody, and they showed granular expression. Every pathological section included 4,800 cells, and there were different numbers of positive cells in each group. FXR expression in the hilar cholangiocarcinoma of rats was significantly lower than that in normal hilar bile duct tissues. GW4064 increased the expression of FXR in tumour tissues. These findings suggest that FXR may be a new therapeutic target and that GW4064 may be helpful in the treatment of hilar cholangiocarcinoma.

Dose caffeinated energy drink is a consideration issue for endurance performance.

Caffeinated energy drinks are commonly taken to improve exercise performance, but there are few studies on the influence of different doses on an athlete's performance. We conducted a double-blind, randomized, counter-balanced, and crossover research study to examine the effects of low caffeinated energy drink (Low ED) or high caffeinated energy drink (High ED) supplement on the performance, haematological response, and oxidative stress in triathletes. Twelve male participants underwent three testing sessions separated by weekly intervals, consisting of sprint triathlon training (0.75 km swim, 20 km cycle, and 5 km run). Before and during the trials, participants were randomly provided with either placebo (PLA) group, Low ED group, or High ED group. Exercise performance in the High ED group decreased significantly compared with the PLA and Low ED groups (p < 0.05). However, participants in the Low ED group also experienced an improved performance (p = 0.054). Analysis of variance revealed no differences among the three groups in cortisol and testosterone levels, or the Borg Rating of Perceived Exertion score (p > 0.5). Furthermore, superoxide dismutase (SOD) was reduced with exercise and were lowest in the High ED group. However, compared with PLA, a significant decrease of thiobarbituric acid reactive substances (TBARS) was observed in Low ED and High ED groups (p < 0.05). This indicates that caffeinated energy drink consumption may improve performance and reduce oxidative stress in sprint triathlon athletes. However, individual differences should be considered when supplementing with caffeinated energy drinks to decrease side effects.

Temperature drives the assembly of Bacillus community in mangrove ecosystem.

Mangroves are located at the interface of terrestrial and marine environments, and experience fluctuating conditions, creating a need to better explore the relative role of the bacterial community. Bacillus has been reported to be the dominant group in the mangrove ecosystem and plays a key role in maintaining the biodiversity and function of the mangrove ecosystem. However, studies on bacterial and Bacillus community across four seasons in the mangrove ecosystem are scarce. Here, we employed seasonal large-scale sediment samples collected from the mangrove ecosystem in southeastern China and utilized 16S rRNA gene amplicon sequencing to reveal bacterial and Bacillus community structure changes across seasons. Compared with the whole bacterial community, we found that Bacillus community was greatly affected by season (temperature) rather than site. The key factors, NO3-N and NH4-N showed opposite interaction with superabundant taxa Bacillus taxa (SAT) and three rare Bacillus taxa including high rare taxa (HRT), moderate rare taxa (MRT) and low rare taxa (LRT). Network analysis suggested the co-occurrence of Bacillus community and Bacillus-bacteria, and revealed SAT had closer relationship compared with rare Bacillus taxa. HRT might act crucial response during the temperature decreasing process across seasons. This study fills a gap in addressing the assembly of Bacillus community and their role in maintaining microbial diversity and function in mangrove ecosystem.

NTCP Change in Rats of Hilar Cholangiocarcinoma and Therapeutic Significance.

Background: The study aims to detect the expression of Na+/taurocholate cotransporter polypeptide in hilar cholangiocarcinoma of rat model, to provide a new therapeutic target for gene therapy of hilar cholangiocarcinoma. Methods: 60 male Wistar rats (weighing 190 ± 8 g) were randomly divided into 3 groups (experimental group, control group, and sham operation group; 20 rats in each group). The 3 groups were fed with standard diet. The QBC939 cell suspension of cholangiocarcinoma was injected into the hilar bile duct in the experimental group with a micro syringe. The control group was injected with normal saline, and the sham operation group was not injected with any drugs. Comprehensive behavior score and Basso Beattie Bresnahan were used to evaluate the mental state and exercise of rats every day. At 5 weeks, one rat in the experimental group was killed, and the changes in hilar bile duct were recorded. The procedure was repeated at one and half months. After one and half months, hilar cholangiocarcinoma only occurred in the experimental group. Pathological examination confirmed the formation of tumor, and hilar bile duct tissues were taken from the 3 groups. Na+/taurocholate cotransporter polypeptide expression in hilar bile duct was detected by real-time polymerase chain reaction and immunohistochemistry. Results: After 2 weeks, the rats in experimental group ate less, and their weight was significantly reduced compared with the other 2 groups. One and half months later, hilar cholangiocarcinoma was detected in 16 rats in the experimental group. The levels of alanine aminotransferase and aspartate transaminase in the experimental group were higher than those in the other 2 groups. The ratio of Na+/taurocholate cotransporter polypeptide/GAPDH mRNA in hilar cholangiocarcinoma, control group, and sham operation group was significantly different. Under the light microscope, Na+/taurocholate cotransporter polypeptide protein reacted with anti-Na+/taurocholate cotransporter polypeptide antibody and showed granular expression. Every pathological section included 4800 cells. 3823 positive cells were in the experimental group, 1765 positive cells were in the control group, and 1823 positive cells were in the sham operation group. Conclusions: Na+/taurocholate cotransporter polypeptide expression in hilar cholangiocarcinoma of rats was significantly higher than normal hilar bile duct tissues, suggesting that drugs targeting Na+/taurocholate cotransporter polypeptide may be a new strategy for the treatment of hilar cholangiocarcinoma.

FXR expression in rats of hilar cholangiocarcinoma.

The study objective was to detect the expression of farnesoid X receptor (FXR) in a rat model of hilar cholangiocarcinoma to provide a new therapeutic target for gene therapy in hilar cholangiocarcinoma. Sixty male Wistar rats (weighing 190 ± 8 g) were randomly divided into three groups (experimental group, control group and sham operation group, 20 rats in each group). The three groups were fed a standard diet. The QBC939 cell suspension of cholangiocarcinoma was injected into the hilar bile duct in the experimental group with a microsyringe. The control group was injected with normal saline, and the sham operation group was not injected with any drugs. A modified tail suspension test (TST) was used to evaluate the mental state and physical activity of rats every day. At 5 weeks, one rat in the experimental group was euthanized, and the changes in the hilar bile duct were recorded. The procedure was repeated at one and half months. After one and half months, hilar cholangiocarcinoma only occurred in the experimental group. Pathological examination confirmed the formation of tumours, and hilar bile duct tissues were taken from the three groups. FXR expression in the hilar bile duct was detected by real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. After two weeks, the rats in the experimental group ate less, and their weight was significantly reduced. One and half months later, hilar cholangiocarcinoma was detected in 16 rats in the experimental group. The levels of alanine aminotransferase and aspartate transaminase in the experimental group were higher than those in the other two groups. The ratio of FXR/GAPDH mRNA was significantly different among the hilar cholangiocarcinoma, control and sham operation groups. Under the light microscope, FXR protein reacted with anti-FXR antibody and showed granular expression. Every pathological section included 4800 cells. A total of 1856 positive cells were in the experimental group, 3279 positive cells were in the control group, and 3371 positive cells were in the sham operation group. FXR expression in the hilar cholangiocarcinoma of rats was significantly lower than that in normal hilar bile duct tissues, suggesting that drugs targeting FXR may be a new strategy for the treatment of hilar cholangiocarcinoma.

Effects of spinetoram and glyphosate on physiological biomarkers and gut microbes in Bombus terrestris.

The sublethal effects of pesticide poisoning will have significant negative impacts on the foraging and learning of bees and bumblebees, so it has received widespread attention. However, little is known about the physiological effects of sublethal spinetoram and glyphosate exposure on bumblebees. We continuously exposed Bombus terrestris to sublethal (2.5 mg/L) spinetoram or glyphosate under controlled conditions for 10 days. The superoxide dismutase, glutathione-S-transferase, carboxylesterase, prophenoloxidase, α-amylase and protease activities, and changes in gut microbes were measured to understand the effects of sublethal pesticide exposure on the physiology and gut microbes of bumblebees. Sublethal pesticide exposure to significantly increased superoxide dismutase activity and significantly decreased gut α-amylase activity in bumblebees but had no significant effect on glutathione-S-transferase, carboxylesterase or gut protease activities. In addition, glyphosate increased the activity of prophenoloxidase. Interestingly, we observed that neither of the two pesticides had a significant effect on dominant gut bacteria, but glyphosate significantly altered the structure of the dominant gut fungal community, and reduced the relative abundance of Zygosaccharomyces associated with fat accumulation. These results suggest that sublethal spinetoram and glyphosate do not significantly affect the detoxification system of bumblebees, but may affect bumblebee health by inhibiting energy acquisition. Our results provide information on the sublethal effects of exposure to low concentrations of glyphosate and spinetoram on bumblebees in terms of physiology and gut microbes.

Stress response mechanisms and description of three novel species Shewanella avicenniae sp. nov., Shewanella sedimentimangrovi sp. nov. and Shewanella yunxiaonensis sp. nov., isolated from mangrove ecosystem.

Three Gram-staining negative, facultatively anaerobic, rod-shaped and motile strains, FJAT-51800T, FJAT-52962T and FJAT-54481T were isolated from the sediment samples of Zhangjiang Estuary Mangrove National Nature Reserve in Fujian Province, China. The 16S rRNA gene sequencing results indicated they could be novel members of the genus Shewanella. The optimum temperature for growth was 30 °C. The respiratory quinones of the strains were ubiquinone Q-7 or Q-8, and menaquinone MK-7. Polar lipids of the strains FJAT-52962T and FJAT-51800T were phosphatidyl glycerol, phosphatidyl ethanolamine, and unidentified aminophospholipids while strain FJAT-54481 consist of phosphatidylglycerol, phosphatidylethanolamine, unidentified aminophospholipids, two unidentified aminolipids and four unidentified lipids. The major fatty acid of the three strains was iso-C15:0. The genomic DNA G + C contents of strains FJAT-51800T, FJAT-52962T and FJAT-54481T were 48.2, 55.3 and 48.1%, respectively. The average nucleotide identity and digital DNA-DNA hybridization values between strains FJAT-51800T, FJAT-52962T and FJAT-54481T and other closely related Shewanella members were below the cut-off level (95-96%) for species identification. Genome analysis showed that these strains encode genes for osmo-regulation. Based on the results of phenotypic, chemotaxonomic and genome analyses, strains FJAT-51800T, FJAT-52962T and FJAT-54481T represent three novel species of the genus Shewanella, for which the names Shewanella avicenniae sp. nov., Shewanella sedimentimangrovi sp. nov., and Shewanella yunxiaonensis sp. nov., are proposed. The type strains are FJAT-51800T (= GDMCC 1.2204T = KCTC 82448T), FJAT-52962T (= MCCC 1K05496T = KCTC 82445T) and FJAT-54481T (= GDMCC 1.2348T = KCTC 82646T).

Bsep expression in hilar cholangiocarcinoma of rat model.

Develop a rat model of hilar cholangiocarcinoma for detecting bile salt export pump (Bsep) expression in hilar cholangiocarcinoma tissues, in order to provide a new therapeutic target for the gene therapy of hilar cholangiocarcinoma. Sixty male Wistar rats (body weight, 190 ± 8 g) were randomly divided into three groups (the experimental group, the control group and the sham operation group, n = 20 each) as follows: The three groups were fed a standard diet, the experimental group was injected by cholangiocarcinoma QBC939 cell suspension along the hilar bile duct into the bile duct bifurcation with microsyringe, the control group was injected by normal saline, the sham operation group did not inject anything. Every day assess the rats' mental state, diet, and motion by using Basso-Beattie-Bresnahan and combined behavioral score. At 4 weeks, one rat of the experimental group was sacrificed after it was administered anesthesia, and we recorded changes in hilar bile duct size, texture, and form. This procedure was repeated at 6 weeks. After 6 weeks, hilar cholangiocarcinoma developed only in the experimental group, thereby establishing an experimental model for studying QBC939-induced hilar cholangiocarcinoma. Tumor formation was confirmed by pathological examination, and hilar bile duct tissues were harvested from both the groups. A real-time polymerase chain reaction assay and an immunohistochemical assay were used to analyze the expression of Bsep in hilar bile duct tissues of each group. From the second week, the rats in experimental group began to eat less, and their body mass decreased compared with control group and sham operation group. After 6 weeks, we detected hilar cholangiocarcinoma in the hilar bile duct tissues of 18 rats (90%) in the experimental group. In the experimental group with hilar cholangiocarcinoma, we found that the levels of total cholesterol, total bilirubin, and direct bilirubin were higher compared with those in the control group and sham operation group. Simultaneously, muddy stones emerged from the bile ducts of rats in the experimental group. The Bsep/Gapdh mRNA ratio in hilar cholangiocarcinoma, control group and sham operation group differed markedly. Light microscopy revealed a granular pattern of Bsep protein expression which reacted with the anti-Bsep antibody. Each section was randomly divided into six regions, with 80 cells were observed in every region. Sections with > 10% positive cells were designated positive, Sections with < 10% positive cells were designated negative. Each group included 4800 cells. In the experimental group, 1200 cells (25%) were positive, in the control group, 3648 cells (76%) were positive and in the sham operation group 3598 cells (75%) were positive, and this difference was statistically significant. Bsep expression significantly decreased in hilar cholangiocarcinoma of rats than those in control group and sham operation group, suggesting that drugs targeting Bsep are a new strategy for hilar cholangiocarcinoma.

Reclassification of Brevibacterium frigoritolerans DSM 8801T as Bacillus frigoritolerans comb. nov. Based on Genome Analysis.

16S rRNA gene sequence analysis showed that the type strain Brevibacterium frigoritolerans DSM 8801T had the highest similarity (99.7%) with the reference strain Bacillus simplex NBRC 15720T, followed by Bacillus muralis DSM 16288T (99.6%), Bacillus butanolivorans DSM 18926T (99.5%), and Bacillus loiseleuriae FJAT-27997T (97.9%). This relationship is confirmed by the phylogenetic analysis indicating that Bre. frigoritolerans DSM 8801T fell in the genus Bacillus group and formed a clade with the closely related Bacillus species. Average nucleotide identity and in silico DNA-DNA hybridization (isDDH) values between strain DSM 8801T and the most closed reference strain Bac. simplex NBRC 15720T were both much lower than species definition threshold values of 95% and 70%, respectively, which indicated strain DSM 8801T should not be affiliated to one of the validly named Bacillus species. The percentage of conserved protein (POCP) values between the strain DSM 8801T and the type strains of the above species were 80.7%, 69.2%, 72.2%, 53.6%, and 50.0%, respectively, higher than the genus definition threshold value of 50%. The main isoprenoid quinone of strain DSM 8801T was MK-7, the main polar lipids were diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), and phosphatidyl ethanolamine (PE), and the major fatty acids were anteiso-C15:0 and iso-C15:0. On the basis of the phenotypic, chemotaxonomic, phylogenetic and genomic characteristics, Bre. frigoritolerans DSM 8801T should belong to the genus Bacillus, and be proposed to reclassify as Bacillus frigoritolerans comb. nov., with the type strain DSM 8801T (=ATCC 25097T  = CCUG 43489T  = CIP 67.20T  = JCM 11681T).

Strong inhibitory activities and action modes of lipopeptides on lipase.

Lipopeptides have been reported to exhibit anti-obesity effects. In this study, we obtained a Bacillus velezensis strain FJAT-52631 that could coproduce iturins, fengycins, and surfactins. Results showed that the FJAT-52631 crude lipopeptide, purified fengycin, iturin, and surfactin standards exhibited strong inhibition activities against lipase with dose-dependence manners (half maximal inhibitory concentration (IC50) = 0.011, 0.005, 0.056, and 0.005 mg/mL, respectively). Moreover, fengycin and surfactin had the comparable activities with orlistat, but iturin not. It was revealed that the inhibition mechanism and type of the lipopeptides were reversible and competitive. The quenching mechanism of lipase was static and only one binding site between lipase and lipopoeptide was inferred from the fluorescence analysis. The docking analysis displayed that fengycin and surfactin could directly interact with the active amino acid residues (Ser or Asp) of lipase, but not with iturin. Our work suggests that the B. velezensis lipopeptides would have great potential to act as lipase inhibitors.

Genomic insights into mite phylogeny, fitness, development, and reproduction.

BACKGROUND: Predatory mites (Acari: Phytoseiidae) are the most important beneficial arthropods used in augmentative biological pest control of protected crops around the world. However, the genomes of mites are far less well understood than those of insects and the evolutionary relationships among mite and other chelicerate orders are contested, with the enigmatic origin of mites at one of the centres in discussion of the evolution of Arachnida. RESULTS: We here report the 173 Mb nuclear genome (from 51.75 Gb pairs of Illumina reads) of the predatory mite, Neoseiulus cucumeris, a biocontrol agent against pests such as mites and thrips worldwide. We identified nearly 20.6 Mb (~ 11.93% of this genome) of repetitive sequences and annotated 18,735 protein-coding genes (a typical gene 2888 bp in size); the total length of protein-coding genes was about 50.55 Mb (29.2% of this assembly). About 37% (6981) of the genes are unique to N. cucumeris based on comparison with other arachnid genomes. Our phylogenomic analysis supported the monophyly of Acari, therefore rejecting the biphyletic origin of mites advocated by other studies based on limited gene fragments or few taxa in recent years. Our transcriptomic analyses of different life stages of N. cucumeris provide new insights into genes involved in its development. Putative genes involved in vitellogenesis, regulation of oviposition, sex determination, development of legs, signal perception, detoxification and stress-resistance, and innate immune systems are identified. CONCLUSIONS: Our genomics and developmental transcriptomics analyses of N. cucumeris provide invaluable resources for further research on the development, reproduction, and fitness of this economically important mite in particular and Arachnida in general.

Two novel alkaliphiles, Bacillus alkalisoli sp. nov., and Bacillus solitudinis sp. nov., isolated from saline-alkali soil.

Two alkaliphilic strains, designated FJAT-45086T and FJAT-45122T, were isolated from alkali soli in Nima County, Tibet, China. Both strains were Gram-positive, rod-shaped and shared low 16S rRNA gene sequence similarity with the members of the genus Bacillus. They contained meso-diaminopimelic acid as the cell-wall diamino acid and MK-7 as the menaquinone. The major fatty acids (>5%) of strain FJAT-45086T were anteiso-C15:0, C16:0, iso-C15:0, C16:1ω11c and anteiso-C17:0, whereas strain FJAT-45122T consisted of iso-C15:0, anteiso-C15:0, iso-C17:1ω10c, iso-C17:0, anteiso-C17:0, C16:0 and C16:1ω11c. The genome G + C content of strains FJAT-45086T and FJAT-45122T was 37.8 and 38.2 mol%, respectively. The polar lipids of strain FJAT-45086T were diphosphatidyl glycerol (DPG), phosphatidyl glycerol (PG), phosphatidyl ethanolamine (PE), and phosphatidyl choline (PC), whereas strain FJAT-45122T consisted of DPG, PG, phosphatidyl methyl ethanolamine (PME) and an unidentified aminophospholipids (UAPL). The average nucleotide identity values of strains FJAT-45086T and FJAT-45122T were below the cut-off level (95-96%) for species delineation. Based on the results, strains FJAT-45086T and FJAT-45122T represent two novel species of the genus Bacillus, for which the names Bacillus alkalisoli sp. nov., and Bacillus solitudinis sp. nov., are proposed. The type strain, FJAT-45122T (=DSM 104631T = CCTCC AB 2016254T), FJAT-45086T (=DSM 104056T = CCTCC AB 2016232T).

Genome-based reclassification of Bacillus okuhidensis as a later heterotypic synonym of Bacillus halodurans.

The present study was carried out to clarify the taxonomic relationship between two closely related Bacillus species, Bacillus okuhidensis Li et al. 2002 and Bacillus halodurans (ex Boyer 1973) Nielsen et al. 1995. The maximum-likelihood tree based on the 16S rRNA gene sequence and the phylogenomic tree based on concatenation of 16 protein-marker genes showed that these species were similar. Average nucleotide identity (ANIm 99.25 %, ANIb 98.2 %) and digital DNA-DNA hybridization values (93.5 %) between B. okuhidensis DSM 13666T and B. halodurans DSM 497T were greater than the threshold values for bacterial species delineation, indicating that they belong to the same species. Therefore, B. okuhidensis Li et al. 2002 should be reclassified as a later heterotypic synonym of B. halodurans (ex Boyer 1973) Nielsen et al. 1995.

Genome-based reclassification of Bacillus plakortidis Borchert et al. 2007 and Bacillus lehensis Ghosh et al. 2007 as a later heterotypic synonym of Bacillus oshimensis Yumoto et al. 2005; Bacillus rhizosphaerae Madhaiyan et al. 2011 as a later heterotypic synonym of Bacillus clausii Nielsen et al. 1995.

In the present study, phylogenetic and genome-based comparison was carried out to clarify the taxonomic positions of alkaliphilic Bacillus species, Bacillus plakortidis, Bacillus lehensis, Bacillus oshimensis, Bacillus rhizosphaerae and Bacillus clausii. Phylogenetic trees based on 16S rRNA gene sequences and concatenated protein marker genes were constructed. Average nucleotide identity (ANI) values were calculated to compare genetic relatedness. In phylogenetic trees, B. plakortidis DSM 19153T, B. lehensis DSM 19099T, and B. oshimensis DSM 18940T; B. rhizosphaerae DSM 21911T and B. clausii DSM 8716T clade together. The average nucleotide identity (ANI) values between B. oshimensis DSM 18940T, B. plakortidis DSM 19153T and B. lehensis DSM 19099T ranged from 98.7-98.8%, while the ANI values between B. rhizosphaerae DSM 21911T and B. clausii DSM 8716T were 95.2-95.5%. The ANI values were higher than the recognized threshold value for bacterial species delineation. Based on phylogenetic and genome comparison we propose reclassification of B. plakortidis and B. lehensis as a later heterotypic synonym of B. oshimensis; B. rhizosphaerae as a later heterotypic synonym of B. clausii.

Bacillus xiapuensis sp. nov., isolated from marine sediment.

A rod-shaped, endospore-forming, aerobic bacterium, designated FJAT-46582T, was isolated from a sediment sample of the coastal region in Xiapu County, Fujian Province in China. Growth was observed at 10-30 °C (optimum, 25 °C), in 0-7.0 % NaCl (0 %) and at pH 6.0-11.0 (pH 8.0), respectively. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the isoprenoid quinone was MK-7. The main fatty acids were anteiso-C17 : 0 (26.5 %), anteiso-C15 : 0 (19.6 %), iso-C15 : 0 (14.4 %) and C16 : 0 (10.5 %). The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidyl ethanolamine. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain FJAT-46582T with the genus Bacillus, and showed the highest sequence similarity to Bacillus thermotolerans SGZ-8T (97.6 %) and Bacillus ectoinformans (97.1 %). The average nucleotide identity and in silico DNA-DNA hybridization values between strain FJAT-46582T and the most closely related species were 72.3 and 22.9 %, respectively, which were much lower than the thresholds commonly used to define species (96 and 70 %, respectively) indicating that it belonged to a different taxon. The DNA G+C content was 44.2 mol%. The phenotypic characters and taxono-genomics study revealed that strain FJAT-46582T represents a novel Bacillus species, for which the name Bacillus xiapuensis sp. nov. is proposed. The type strain is FJAT-46582T (=JCM 33155=CCTCC AB 2017047T).

Bacillus urbisdiaboli sp. nov., isolated from soil sampled in Xinjiang.

A rod-shaped, endospore-forming, facultative anaerobic bacterium, designated FJAT-45385T, was isolated from soil collected from Devil City in the Xinjiang Autonomous Region in China. Growth was observed at 20-40 °C (optimum, 30 °C), pH 7.0-11.0 (pH 9.0) and in 0-10.0 % NaCl (4 %), respectively. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the isoprenoid quinone was MK-7. The main fatty acids were anteiso-C15 : 0 (37.4 %), iso-C15 : 0 (15.1 %) and C16 : 0 (12.6 %). The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain FJAT-45385T to the genus Bacillus, and showed the highest sequence similarity to Bacillus wakoensis DSM 2521T (96.0 %). The average nucleotide identity and in silico DNA-DNA hybridization values between strain FJAT-45385T and its closest related species were 67.8 and 35.5 %, respectively, which were much lower than the thresholds commonly used to define species (96 and 70 %, respectively) indicating that it belong to a different taxon. The DNA G+C content was 38.1 mol%. The phenotypic characters and taxono-genomics study revealed that strain FJAT-45385T represents a novel Bacillus species, for which the name Bacillus urbisdiaboli sp. nov. is proposed. The type strain is FJAT-45385T (=DSM 104651T=CCTCC AB 2016263T).

TDDFT study on aluminum and fluoride dual-sensing mechanism of a Schiff-Base sensor.

The aluminum and fluoride dual-sensing mechanism of a previously reported sensor with a Schiff-base moiety (Spectrochim. Acta A, 2017, 183, 267-274) has been investigated by density functional theory (DFT) and time-dependent DFT (TDDFT) methods. The present calculations reproduce the photoproperties of the sensor as well as its aluminum and fluoride complexes, which illustrates that DFT and TDDFT constitute a reliable tool for uncovering detailed fluorescence-based sensing mechanisms in diverse electronic states. Theoretical results indicate that there are two OH⋯N hydrogen bonds in the sensor and two OH⋯F hydrogen bonds in its F¯ complex. Different degrees of coplanarity caused by these hydrogen bonds are responsible for their distinct absorption wavelengths. However, excited-state geometry optimization and a scan of the potential-energy surface show that there is twisted intramolecular charge transfer about the CN bond in the sensor molecule and an excited-state proton-transfer process from the fluoride anion to the neighboring N atom in the fluoride-sensor complex, whereby the fluorescence is quenched. A chelation-enhanced fluorescence effect associated with the aluminum-sensor complex shows a different excited-state process. The local excitation and emission occur exclusively within the planar fluorophore, and negligible structural change upon excitation of the aluminum-sensor complex leads to its strong fluorescence. Therefore, it is theoretically explained why the sensor may be successfully used to analyze the fluoride anion by absorption spectroscopy and the aluminum cation by emission spectroscopy.

Bacillus populi sp. nov. isolated from Populus euphratica rhizosphere soil of the Taklamakan desert.

A rod-shaped, endospore-forming, aerobic bacterium, designated FJAT-45347T, was isolated from rhizosphere soil collected from the Taklamakan desert in Xinjiang (PR China). Growth was observed at 15-35 °C (optimum 25 °C), in 0 % and 20.0 % NaCl (optimum 8.0 %) and at pH 7.5-12.0 (optimum 8.0), respectively. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the isoprenoid quinone was MK-7. The main fatty acids were iso-C15 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phylogenetic analysis based on 16S rRNA gene sequences affiliated FJAT-45347T to the genus Bacillus, and it showed the highest sequence similarities to Bacillus clarkii DSM 8720T (96.1 %). The average nucleotide identity and in silico DNA-DNA hybridization values between FJAT-45347T and the most closely related species were 68.5 and 26.2 %, respectively, which were lower than the thresholds commonly used to define species (96 and 70 %, respectively), indicating that it represented a member of a different taxon. The DNA G+C content was 40.6 mol%. The phenotypic characters and taxono-genomics study revealed that FJAT-45347T represents a novel species of the genus Bacillus, for which the name Bacilluspopuli sp. nov. is proposed. The type strain is FJAT-45347T (=DSM 104632T=CCTCC AB 2016257T).