Characterization of feline-originated probiotics Lactobacillus rhamnosus CACC612 and Bifidobacterium animalis subsp. lactis CACC789 and and evaluation of their host response.

BACKGROUND: Probiotics are beneficial for animal health and new potential probiotics need to be characterized for their prospective use in improving animal health. In this study, 32 bacterial strains were isolated from a Norwegian forest cat (castrated, 12 years old) and a Persian cat (castrated, 10 years old), which were privately owned and had indoor access. RESULTS: Lactobacillus rhamnosus CACC612 (CACC612) and Bifidobacterium animalis subsp. lactis CACC789 (CACC789) were selected as potential probiotics; characterization of the two strains showed equivalent acid tolerance, similar cell adhesion rates on the HT-29 monolayer cell line, and superior bile tolerance compared to Lactobacillus rhamnosus GG (LGG). Subsequently, they exhibited inhibitory effects against a broad spectrum of pathogenic bacteria, including E. coli (KCTC 2617), Salmonella Derby (NCCP 12,238), Salmonella Enteritidis (NCCP 14,546), Salmonella Typhimurium (NCCP 10,328), Clostridium difficile JCM 1296T. From evaluating host effects, the viability of the feline macrophage cell line (Fcwf-4) increased with the treatment of CACC612 or CACC789 (P < 0.05). The induced expression of immune-related genes such as IFN-γ, IL1ß, IL2, IL4, and TNF-α by immune stimulation was significantly attenuated by the treatment of CACC612 or CACC789 (P < 0.05). When 52 clinical factors of sera from 21 healthy cats were analyzed using partial least squares discriminant analysis (PLS-DA), the animals were obviously clustered before and after feeding with CACC612 or CACC789. In addition, hemoglobin and mean corpuscular hemoglobin concentration (MCHC) significantly increased after CACC612 feeding (P < 0.05). CONCLUSIONS: In this study, feline-originated probiotics were newly characterized and their potentially probiotic effects were evaluated. These results contribute to our understanding of the functional effects of feline-derived probiotics and support their industrial applications.

First Report of Leaf Spot on Eriobotrya japonica Caused by Alternaria alternata in Southwest Korea.

Loquat (Eriobotrya japonica) is a crop cultivated in Southwest Korea, covering an area of 101 ha and yielding 120 tons at harvest (KASS, 2024). Due to its high-income potential, the cultivation area is gradually expanding. In May 2023, 30% of leaf brown spots were observed on all three trees in the Suncheonman National Garden, Suncheon (3488'57.97" N, 12750'92.83" E). As the disease progressed, the brown spot gradually enlarged, turning greyish-ivory inside and forming concentric circles. Three leaf lesions from each tree were cut into 5 x 5 mm pieces, surface-sterilized with 70% ethanol for 1 min, and washed in sterile water three times to isolate the pathogen potentially responsible for these symptoms. The samples obtained were subsequently cultured on 1.5% water agar and then incubated in the dark at 25℃. A total of nine isolates were obtained, with three isolates from each of the three trees through single-spore isolation, namely SYP-1202-1 to 3, SYP-1202-4 to 6, and SYP-1202-7 to 9. The colonies reached 90 mm in diameter after 10 days on potato dextrose agar (PDA), initially dark green, and turned sooty gray after 2 weeks. The hyphae grown on a 0.6% KCl medium for 3 days produced long chains containing three to twelve conidia. The conidia were ellipsoidal or obpyriform in shape and light brown. The conidiophores were straight or curved, measuring 12.1-75.3 x 1.6-4.8 µm (n = 100). The primary and secondary conidia measured length × width of 19.1-60.6 × 6.1-14.4 µm and 8.4-27.8 × 3.5-9.5 µm (n = 100), respectively. The conidia had 1 to 7 transverse and 0 to 3 vertical septa. The morphology of the nine isolates was identical and consistent with Alternaria species (van der Waals et al., 2011; Woudenberg et al., 2015). For molecular identification, ITS (OR844500 to OR844508), GAPDH (OR866383 to OR866391), TEF1 (OR866392 to OR866400), RPB2 (OR866401 to OR866409), Alt a1 (OR866410 to OR866418), endoPG (OR866419 to OR866427), and OPA10-2 (OR866428 to OR866436) sequences from SYP-1202-1 to 9 showed a 100% (515 bp/515 bp), 100% (579/579), 100% (240/240), 100% (753/753), 95.1% (449/472), 100% (448/448), and 100% (634/634) identity with that of type strain A. alternata CBS 115152 (KP124348, KP124202, KP125124, KP124816, KP123896, KP124049, and KP124658, respectively). A pathogenicity test was conducted on three 5-year-old E. japonica cultivar Daebang trees in pots. The surface of the five leaves per tree was sterilized with 70% ethanol for 1 min. Before inoculation, the leaves were wounded with sterile needles and sprayed with the conidial suspension (1×106 conidia/ml) produced from a 1-week-old culture grown on PDA. In contrast, control leaves were sprayed with sterile distilled water. The inoculated leaves were wrapped with black plastic bags and kept at 100% relative humidity for two days. At seven days post-inoculation, symptoms were observed on the wounded leaves, whereas the nonwounded and control leaves did not exhibit any symptoms. The experiment was performed three times in the greenhouse. For each experiment, pathogens were reisolated from the two symptomatic leaves per plant. The identity of the reisolated pathogens was then confirmed via analysis of ITS and RPB2 genes, thereby confirming adherence to Koch's postulates. To the best of our knowledge, this is the first report of E. japonica being infected by A. alternata in Korea. This report provides important information to support effective disease control strategies for E. japonica in orchards in southern Korea.

Anti-inflammatory potential via the MAPK signaling pathway of Lactobacillus spp. isolated from canine feces.

Two probiotic candidates, Lactobacillus reuteri C1 (C1) and Lactobacillus acidophilus C5 (C5), which were previously isolated from canines, were evaluated in the present study. L. reuteri and L. acidophilus have anti-oxidant, anti-inflammatory, immune-enhancing, and anti-cancer properties and exhibit various probiotic effects in humans and animals. The strains C1 and C5 demonstrated good tolerance to acid and bile salt exposure, exhibited effective adhesion to HT-29 cell monolayer, and displayed sensitivity to antibiotics, thus affirming their probiotic characteristics. Moreover, C1 and C5 exhibited the ability to downregulate the expression of inducible NO synthase (iNOS), an immunomodulatory factor, leading to a reduction in NO production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. These strains also demonstrated potent anti-inflammatory effects in LPS-stimulated RAW 264.7 cells, achieved through the augmentation of anti-inflammatory cytokine IL-10 expression and the inhibition of pro-inflammatory cytokine IL-1ß expression. These anti-inflammatory effects of C1 and C5 were closely associated with the mitogen-activated protein kinase (MAPK) signaling pathway. The results of the present study suggest that the C1 and C5 probiotic candidates attenuate LPS-induced inflammation via the MAPK signaling pathway and the strains can be used as probiotics considering their anti-inflammatory potential.

Isolation and Identification of Alternaria alternata from Potato Plants Affected by Leaf Spot Disease in Korea: Selection of Effective Fungicides.

Brown leaf spot disease caused by Alternaria spp. is among the most common diseases of potato crops. Typical brown spot symptoms were observed in commercial potato-cultivation areas of northern Korea from June to August 2020-2021. In total, 68 isolates were collected, and based on sequence analysis of the internal transcribed spacer (ITS) region, the collected isolates were identified as Alternaria spp. (80.9%). Phylogenetic analysis revealed that a majority of these isolates clustered within a clade that included A. alternata. Additionally, the ITS region and rpb2 yielded the most informative sequences for the identification of A. alternata. Pathogenicity tests confirmed that the collected pathogens elicited symptoms identical to those observed in the field. In pathogenicity tests performed on seven commercial cultivars, the pathogens exhibited strong virulence in both wound and non-wound inoculations. Among the cultivars tested, Arirang-1ho, Arirang-2ho, and Golden Ball were resistant to the pathogens. Furthermore, among the fungicides tested in vitro, mancozeb and difenoconazole were found to be effective for inhibiting mycelial growth. In summary, our findings suggest that A. alternata plays a critical role in leaf disease in potato-growing regions and emphasise the necessity of continuous monitoring and management to protect against this disease in Korea.

Assessing the Probiotic Effects of Pediococcus pentosaceus CACC616 in Weaned Piglets.

During weaning, piglets experience various stressor events that disrupt their gut microbiota and immune balance, decrease growth parameters, and increase mortality rates. In this study, we assessed the efficacy of Pediococcus pentosaceus CACC616 as a probiotic supplement. We characterized this strain and evaluated its effect on improving growth performance, modulating gut microbiota composition, and reducing noxious odor components in weaned piglets compared to a non-supplementary diet (control). During the 26-day period, 40 crossbred weaned piglets were randomly assigned to pens with 20 animals each in two groups: control and treatment groups with CACC616. On day 26, the treatment group exhibited a lower feed conversion ratio (FCR) and a significant alteration in gut microbial composition, correlating with improved growth parameters and gut health (p < 0.05). The treatment group also exhibited significantly reduced digestibility- and intestinal-environment-related noxious odor components (p < 0.05). The CACC616 strain effectively reduced pathogenic genera numbers, including Campylobacter, Mogibacterium, Escherichia-Shigella, and Desulfovibrio spp., with the treatment group exhibiting lower fecal calprotectin levels than the control group (p < 0.05). Overall, this study revealed that the functional probiotic CACC616 contributes to enhanced FCR and effectively modulates weaned piglets' inflammation and intestinal microbiota.

Complete genome sequence of Pediococcus acidilactici CACC 537 isolated from canine.

Pedi coccus acidilactici CACC 537 was isolated from canine feces and reported to have probiotic properties. We aimed to characterize the potential probiotic properties of this strain by functional genomic analysis. Complete genome sequencing of P. acidilactici CACC 537 was performed using a PacBio RSII and Illumina platform, and contained one circular chromosome (2.0 Mb) with a 42% G + C content. The sequences were annotation revealed 1,897 protein-coding sequences, 15 rRNAs, and 56 tRNAs. It was determined that P. acidilactici CACC 537 genome carries genes known to be involved in the immune system, defense mechanisms, restriction-modification (R-M), and the CRISPR system. CACC 537 was shown to be beneficial in preventing pathogen infection during the fermentation process, help host immunity, and maintain intestinal health. These results provide for a comprehensive understanding of P. acidilactici and the development of industrial probiotic feed additives that can help improve host immunity and intestinal health.

Qualitative and Quantitative Analysis of the Major Bioactive Components of Juniperus chinensis L. Using LC-QTOF-MS and LC-MSMS and Investigation of Antibacterial Activity against Pathogenic Bacteria.

Plants in the genus Juniperus have been reported to produce a variety of chemical components, such as coumarins, flavonoids, lignans, sterols, and terpenoids. Here, ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) were applied to qualitatively and quantitatively analyze the major bioactive components in an ethanolic crude extract from the leaves of Juniperus chinensis L., which grows naturally in Korea. In addition, the antibacterial activity of the crude extract against pathogenic bacteria was investigated. Using LC-QTOF-MS analysis, we identified ten compounds, of which six were confirmed to be flavonoid and lignan-based components as the major bioactive components, i.e., isoquercetin, quercetin-3-O-α-l-rhamnoside, hinokiflavone, amentoflavone, podocarpusflavone A, and matairesinoside. Among them, a quantitative analysis performed using LC-MS/MS revealed that the levels of quercetin-3-O-α-l-rhamnoside and amentoflavone in the crude extract were 203.78 and 69.84 mg/g, respectively. Furthermore, the crude extract exhibited potential antibacterial activity against 10 pathogenic bacteria, with the highest antibacterial activity detected against Bordetella pertussis. Thus, further studies of the leaf extract of J. chinensis L. must be carried out to correlate the compounds present in the extract with the antibacterial activity and elucidate the mechanisms of action of this extract against bacteria.

Complete genome sequence of functional probiotic candidate Lactobacillus amylovorus CACC736.

Lactobacillus amylovorus CACC736 was originated from swine feces in Korea. The complete genome sequences of the strain contained one circular chromosome (2,057,809 base pair [bp]) with 38.2% guanine-cytosine (GC) content and two circular plasmids, namely, pCACC736-1 and pCACC736-2. The predicted protein-coding genes, which are encoding the clustered regularly interspaced short palindromic repeats (CRISPR)-associated proteins, biosynthesis of bacteriocin (helveticin J), and the related proteins of the bile, acid tolerance. Notably, the genes related to vitamin B-group biosynthesis (riboflavin and cobalamin) were also found in L. amylovorus CACC736. Collectively, the complete genome sequence of the L. amylovorus CACC736 will aid in the development of functional probiotics in the animal industry.

Identification and Comparison of Bioactive Components of Two Dryopteris sp. Extract Using LC-QTOF-MS.

Dryopteris sp. is known for its various pharmacological effects and is used as a traditional medicine in Asia. The present study investigated the chemical composition and antimicrobial activity of Dryopteris sp. distributed in Korea. The chemical compounds in the ethanolic extracts of Dryopteris lacera and Dryopteris bissetiana were investigated by ultra-high performance liquid chromatography-quadrupole time-of-flight-mass spectrometry analysis and identified by exploring the UNIFI traditional medicine library. Flavonoids such as juglanin, 6-hydroxyluteolin 7-O-laminaribioside, peltatoside, kaempferitrin, hyperoside, and astragalin were identified in both D. lacera and D. bissetiana. Neochlorogenic acid was identified as a caffeoylquinic acid in D. bissetiana. Both extracts of D. lacera and D. bissetiana exhibited antibacterial activity against Gram-positive pathogens, Staphylococcus aureus and Streptococcus mutans. The minimum inhibitory concentration of D. bissetiana against S. aureus was less than 625 ppm. The antibacterial activity was attributed to the identified phenolic compounds, juglanin, 6-hydroxyluteolin 7-O-laminaribioside, kaempferitrin, astragalin, and neochlorogenic acid. Therefore, D. lacera and D. bissetiana can be used as Gram-positive selective antibiotics for further investigation.

Bacillus velezensis TSA32-1 as a Promising Agent for Biocontrol of Plant Pathogenic Fungi.

The use of synthetic fungicides has caused major problems such as soil and water pollution and negatively affects non-target species. Microbial biocontrol agents are needed for crop disease management to reduce agrochemical use. Bacillus and related genera produce secondary metabolites with agricultural applications, such as the pathogen-control agent Bacillus velezensis. We isolated B. velezensis TSA32-1 from soil and identified its characteristics by sequencing its 16S rRNA. B. velezensis TSA32-1 showed enzyme activity and antimicrobial effects against phytopathogenic fungi by inhibiting the growth of Fusarium graminearum, F. fujikuroi, Alternatia alternate, and Diaporthe actinidiae. Additionally, B. velezensis TSA32-1 protected diseases in corn and pepper seeds caused by F. graminearum and Pythium ultimum. The complete genome of B. velezensis TSA32-1 was 4.05 Mb with a G+C content of 46.3 mol % and possessed the bacillaene biosynthesis cluster, a polyketide that inhibits protein biosynthesis. We also detected a surfactin synthesis cluster, known as non-ribosomal peptide synthetases, which biosynthesizes the antibacterial substance lipopeptide. Surfactin, and fengycin family compounds, secondary metabolites known as key factors in biological control, also detected B. velezensis TSA32-1 which shows potential as a biocontrol agent for controlling plant pathogens in agriculture.

Complete genome sequencing and comparative genomic analysis of Lactobacillus acidophilus C5 as a potential canine probiotics.

Lactobacillus acidophilus is a gram-positive, microaerophilic, and acidophilic bacterial species. L. acidophilus strains in the gastrointestinal tracts of humans and other animals have been profiled, but strains found in the canine gut have not been studied yet. Our study helps in understanding the genetic features of the L. acidophilus C5 strain found in the canine gut, determining its adaptive features evolved to survive in the canine gut environment, and in elucidating its probiotic functions. To examine the canine L. acidophilus C5 genome, we isolated the C5 strain from a Korean dog and sequenced it using PacBio SMRT sequencing technology. A comparative genomic approach was used to assess genetic relationships between C5 and six other strains and study the distinguishing features related to different hosts. We found that most genes in the C5 strain were related to carbohydrate transport and metabolism. The pan-genome of seven L. acidophilus strains contained 2,254 gene families, and the core genome contained 1,726 gene families. The phylogenetic tree of the core genes in the canine L. acidophilus C5 strain was very close to that of two strains (DSM20079 and NCFM) from humans. We identified 30 evolutionarily accelerated genes in the L. acidophilus C5 strain in the ratio of non-synonymous to synonymous substitutions (dN/dS) analysis. Five of these thirty genes were associated with carbohydrate transport and metabolism. This study provides insights into genetic features and adaptations of the L. acidophilus C5 strain to survive the canine intestinal environment. It also suggests that the evolution of the L. acidophilus genome is closely related to the host's evolutionary adaptation process.

Complete genome sequence of Bacillus coagulans CACC834 isolated from canine.

Bacillus coagulans CACC 834 was isolated from canine feces, and its potential probiotic properties were characterized by functional genome analysis. Whole-genome sequencing of B. coagulans CACC 834 was performed using the PacBio RSII platforms. The complete genome assembly consisted of one circular chromosome (3.1 Mb) with guanine (G) + cytosine (C) content of 47.1%. Annotation revealed 3,181 protein-coding sequences (CDSs), 30 rRNAs, and 83 tRNAs. Gene associated 11% of the genes were involved in replication, recombination, and repair. We also annotated various stress-related, acid resistance, bile salt resistance and adhesion-related domains in this strain, which likely provide support in exerting probiotic action by survival under gastrointestinal tract. These results add to our comprehensive understanding of B. coagulans and suggest potential mammal-related industrial applications.

Characterization and Functional Test of Canine Probiotics.

Probiotics can modulate the composition of gut microbiota and benefit the host animal health in multiple ways. Lactic acid bacteria (LAB), mainly Lactobacillus and Bifidobacterium species, are well-known microbes with probiotic potential. In the present study, 88 microbial strains were isolated from canine feces and annotated. Among these, the four strains CACC517, 537, 558, and 566 were tested for probiotic characteristics, and their beneficial effects on hosts were evaluated both in vitro and in vivo; these strains exhibited antibiosis, antibiotic activity, acid and bile tolerance, and relative cell adhesion to the HT-29 monolayer cell line. Byproducts of these strains increased the viability and decreased oxidative stress in mouse and dog cell lines (RAW264.7 and DH82, respectively). Subsequently, when the probiotics were applied to the clinical trial, changes in microbial composition and relative abundance of bacterial strains were clearly observed in the experimental animals. Experimental groups before and after the application were obviously separated from PCA analysis of clinical results. Conclusively, these results could provide comprehensive understanding of the effects of probiotic strains (CACC517, 537, 558, and 566) and their industrial applications.

Comparative Pathogenicity and Host Ranges of Magnaporthe oryzae and Related Species.

Host shifting and host expansion of fungal plant pathogens increases the rate of emergence of new pathogens and the incidence of disease in various crops, which threaten global food security. Magnaporthe species cause serious disease in rice, namely rice blast disease, as well as in many alternative hosts, including wheat, barley, and millet. A severe outbreak of wheat blast due to Magnaporthe oryzae occurred recently in Bangladesh, after the fungus was introduced from South America, causing great loss of yield. This outbreak of wheat blast is of growing concern, because it might spread to adjacent wheat-producing areas. Therefore, it is important to understand the host range and population structure of M. oryzae and related species for determining the evolutionary relationships among Magnaporthe species and for managing blast disease in the field. Here, we collected isolates of M. oryzae and related species from various Poaceae species, including crops and weeds surrounding rice fields, in Korea and determined their phylogenetic relationships and host species specificity. Internal transcribed spacer-mediated phylogenetic analysis revealed that M. oryzae and related species are classified into four groups primarily including isolates from rice, crabgrass, millet and tall fescue. Based on pathogenicity assays, M. oryzae and related species can infect different Poaceae hosts and move among hosts, suggesting the potential for host shifting and host expansion in nature. These results provide important information on the diversification of M. oryzae and related species with a broad range of Poaceae as hosts in crop fields.

Comparative genomics of canine Lactobacillus reuteri reveals adaptation to a shared environment with humans.

BACKGROUND: Lactobacillus reuteri is a gram-positive, non-motile bacterial species that has been used as a representative microorganism model to describe the ecology and evolution of vertebrate gut symbionts. OBJECTIVE: Because the genetic features and evolutionary strategies of L. reuteri from the gastrointestinal tract of canines remain unknown, we tried to construct draft genome canine L. reuteri and investigate modified, acquired, or lost genetic features that have facilitated the evolution and adaptation of strains to specific environmental niches by this study. METHODS: To examine canine L. reuteri, we sequenced an L. reuteri strain isolated from a dog in Korea. A comparative genomic approach was used to assess genetic diversity and gain insight into the distinguishing features related to different hosts based on 27 published genomic sequences. RESULTS: The pan-genome of 28 L. reuteri strains contained 7,369 gene families, and the core genome contained 1070 gene families. The ANI tree based on the core genes in the canine L. reuteri strain (C1) was very close to those for three strains (IRT, DSM20016, JCM1112) from humans. Evolutionarily, these four strains formed one clade, which we regarded as C1-clade in this study. We could investigate a total of 32,050 amino acid substitutions among the 28 L. reuteri strain genomes. In this comparison, 283 amino acid substitutions were specific to strain C1 and four strains in C1-clade shared most of these 283 C1-strain specific amino acid substitutions, suggesting strongly similar selective pressure. In accessory genes, we could identify 127 C1-clade host-specific genes and found that several genes were closely related to replication, recombination, and repair. CONCLUSION: This study provides new insights into the adaptation of L. reuteri to the canine intestinal habitat, and suggests that the genome of L. reuteri from canines is closely associated with their living and shared environment with humans.

Indoor air quality in California homes with code-required mechanical ventilation.

Data were collected in 70 detached houses built in 2011-2017 in compliance with the mechanical ventilation requirements of California's building energy efficiency standards. Each home was monitored for a 1-week period with windows closed and the central mechanical ventilation system operating. Pollutant measurements included time-resolved fine particulate matter (PM2.5 ) indoors and outdoors and formaldehyde and carbon dioxide (CO2 ) indoors. Time-integrated measurements were made for formaldehyde, NO2 , and nitrogen oxides (NOX ) indoors and outdoors. Operation of the cooktop, range hood, and other exhaust fans was continuously recorded during the monitoring period. Onetime diagnostic measurements included mechanical airflows and envelope and duct system air leakage. All homes met or were very close to meeting the ventilation requirements. On average, the dwelling unit ventilation fan moved 50% more airflow than the minimum requirement. Pollutant concentrations were similar to or lower than those reported in a 2006-2007 study of California new homes built in 2002-2005. Mean and median indoor concentrations were lower by 44% and 38% for formaldehyde and 44% and 54% for PM2.5 . Ventilation fans were operating in only 26% of homes when first visited, and the control switches in many homes did not have informative labels as required by building standards.

Genome analysis of Bacteroides sp.CACC 737 isolated from feline for its potential application.

Bacteroides sp. CACC 737 was isolated from a feline, and its potential probiotic properties were characterized using functional genome analysis. Whole-genome sequencing was performed using the PacBio RSII and Illumina HiSeq platforms. The complete genome of strain CACC 737 contained 4.6 Mb, with a guanine (G) + cytosine (C) content of 45.8%, six cryptic plasmids, and extracellular polysaccharide gene as unique features. The strain was beneficial to animal health when consumed as feed, for example, for ameliorating immunological dysfunctions and metabolic disorders. The genome information adds to the comprehensive understanding of Bacteroides sp. and suggests potential animal-related industrial applications for this strain.

Investigating the probiotic characteristics of four microbial strains with potential application in feed industry.

The present study aimed to evaluate the probiotic characteristics of certain microbial strains for potential use as feed additives. Three bacterial strains and a yeast previously isolated from different environments were investigated. The strains were subjected to molecular identification and established as Lactobacillus paracasei CP133, Lactobacillus plantarum CP134, Bacillus subtilis CP350 and Saccharomyces cerevisiae CP605. Lactobacillus sp. CP133 and CP134 exhibited antibiosis, antibiotic activity, and relative odor reduction ability. Bacillus subtilis CP350 was thermotolerant, reduced hydrogen sulfide gas and showed significant proteolytic activity, whereas Saccharomyces cerevisiae CP605 exhibited high acid and bile salt tolerance. In general, the isolates in this study demonstrated improved functional characteristics, particularly acid and bile tolerance and relative cell adhesion to HT-29 monolayer cell line. Results in this work provides multifunctional probiotic characteristics of the strains for potential development of probiotics and cleaning of the environment.

Timing of Fusarium Head Blight Infection in Rice by Heading Stage.

Fusarium graminearum causes the devastating plant disease Fusarium head blight and produces mycotoxins on small cultivated grains. To investigate the timeframe of F. graminearum infection during rice cultivation, a spore suspension of F. graminearum was applied to the rice cultivars Dongjin 1 and Nampyeongbyeo before and after the heading stage. The disease incidence rate was the highest (50%) directly after heading, when the greatest number of flowers were present, while only 10% of the rice infected 30 days after heading showed symptoms. To understand the mechanism of infection, an F. graminearum strain expressing green fluorescent protein (GFP) was inoculated, and the resulting infections were visually examined. Spores were found in all areas between the glume and inner seed, with the largest amount of GFP detected in the aleurone layer. When the inner part of the rice seed was infected, the pathogen was mainly observed in the embryo. These results suggest that F. graminearum migrates from the anthers to the ovaries and into the seeds during the flowering stage of rice. This study will contribute to uncovering the infection process of this pathogen in rice.

MP-V1 from the Venom of Social Wasp Vespula vulgaris Is a de Novo Type of Mastoparan that Displays Superior Antimicrobial Activities.

Mastoparans from the venom of social wasps have attracted considerable attention as effective antibiotic candidates. In this study, mastoparan V1 (MP-V1) from Vespula vulgaris was first disclosed to have a peptide amino acid sequence distinct from typical mastoparans and its biochemical properties and antimicrobial effects were compared with those of typical mastoparans MP-L, -X(V) and -B. Circular dichroism (CD) spectroscopy revealed that MP-V1 and -X(V) form more stable α-helical conformations in lipid membrane-like environments than MP-L and -B. In parallel, these two also showed more effective antimicrobial activities against the pathogens than did MP-L and -B. Although MP-V1 had a less stable α-helical conformation than MP-X(V), it showed stronger antimicrobial effects against Streptococcus mutans and Salmonella enterica than MP-X(V). In the meantime, analysis of hemolytic activity revealed a range of doses (~50 µM) that exhibited little potent cytotoxicity on human erythrocytes. Finally, the atypical MP-V1 peptide amino acid sequence provided important clues to understanding its antimicrobial mechanism from a structural perspective. Therefore, it has been concluded that MP-V1 is a de novo type of mastoparan with superior antimicrobial activities against both pathogenic bacteria and fungi, which may be useful in developing multipurpose antimicrobial drugs against infectious diseases.