The Prospect of Hydrolytic Enzymes from Bacillus Species in the Biological Control of Pests and Diseases in Forest and Fruit Tree Production.

Plant diseases and insect pest damage cause tremendous losses in forestry and fruit tree production. Even though chemical pesticides have been effective in the control of plant diseases and insect pests for several decades, they are increasingly becoming undesirable due to their toxic residues that affect human life, animals, and the environment, as well as the growing challenge of pesticide resistance. In this study, we review the potential of hydrolytic enzymes from Bacillus species such as chitinases, ß-1,3-glucanases, proteases, lipases, amylases, and cellulases in the biological control of phytopathogens and insect pests, which could be a more sustainable alternative to chemical pesticides. This study highlights the application potential of the hydrolytic enzymes from different Bacillus sp. as effective biocontrol alternatives against phytopathogens/insect pests through the degradation of cell wall/insect cuticles, which are mainly composed of structural polysaccharides like chitins, ß-glucans, glycoproteins, and lipids. This study demonstrates the prospects for applying hydrolytic enzymes from Bacillus sp. as effective biopesticides in forest and fruit tree production, their mode of biocidal activity and dual antimicrobial/insecticidal potential, which indicates a great prospect for the simultaneous biocontrol of pests/diseases. Further research should focus on optimizing the production of hydrolytic enzymes, and the antimicrobial/insecticidal synergism of different Bacillus sp. which could facilitate the simultaneous biocontrol of pests and diseases in forest and fruit tree production.

Entomopathogenic Potential of Bacillus velezensis CE 100 for the Biological Control of Termite Damage in Wooden Architectural Buildings of Korean Cultural Heritage.

Biocontrol strategies are gaining tremendous attention in insect pest management, such as controlling termite damage, due to the growing awareness of the irreparable harm caused by the continuous use of synthetic pesticides. This study examines the proteolytic and chitinolytic activities of Bacillus velezensis CE 100 and its termiticidal effect through cuticle degradation. The proteolytic and chitinolytic activities of B. velezensis CE 100 systematically increased with cell growth to the respective peaks of 68.3 and 128.3 units/mL after seven days of inoculation, corresponding with the highest cell growth of 16 × 107 colony-forming units (CFU)/mL. The in vitro termiticidal assay showed that B. velezensis CE 100 caused a rapid and high rate of termite mortality, with a median lethal time (LT50) of >1 h and the highest mortality rates of 91.1% and 92.2% recorded at 11 h and 12 h in the bacterial broth culture and crude enzyme fraction, respectively. In addition to broken setae and deformed sockets, termites treated with the bacterial broth culture exhibited degraded epicuticles, while the crude enzyme fraction caused severe disintegration of both the epicuticle and endocuticle. These results indicate the tremendously higher potential of B. velezensis CE 100 in the biological control of subterranean termites compared to the previously used entomopathogenic bacteria.

Control of Fungal Diseases and Fruit Yield Improvement of Strawberry Using Bacillus velezensis CE 100.

Due to the increasing health and environmental risks associated with the use of fungicides in agriculture, alternatives-such as using plant growth-promoting bacteria (PGPB) to suppress phytopathogens-that simultaneously improve plant yield, are important. This study evaluated the biocontrol efficiency of Bacillus velezensis CE100 against Macrophomina phaseolina and Fusarium oxysporum f. sp. fragariae, the respective causal agents for charcoal rot and fusarium wilt diseases in strawberry, and its potential to enhance strawberry growth and fruit production. B. velezensis CE 100 produced fungal cell wall-degrading enzymes, chitinases, and ß-1,3-glucanases; and inhibited the mycelial growth of M. phaseolina and F. oxysporum f. sp. fragariae by 64.7% and 55.2%, respectively. The mycelia of both phytopathogenic fungi showed severe swelling and rupturing of the hyphae compared to the smooth, normal growth in the control group. Moreover, B. velezensis CE100 produced up to 2.8 units/mL of indole-3-acetic acid (IAA) during incubation and enhanced root biomass in strawberries. Consequently, B. velezensis CE 100 not only increased the fruit yield of strawberries by controlling the fungal diseases but also through enhancing plant growth. The findings of this study indicate that B. velezensis CE100 could be a safe, ecofriendly biocontrol alternative to chemical fungicides in strawberry production.

Biological Control of Leaf Blight Disease Caused by Pestalotiopsis maculans and Growth Promotion of Quercus acutissima Carruth Container Seedlings Using Bacillus velezensis CE 100.

Leaf blight disease caused by Pestalotiopsismaculans lead to deleterious losses in the quality of forest container seedlings. The use of plant growth-promoting bacteria provides a promising strategy to simultaneously control diseases and enhance forest seedling production. This study investigated the biocontrol of leaf blight disease and growth promotion potential of Bacillus velezensis CE 100 in Quercus acutissima Carruth seedlings. B. velezensis CE 100 produced cell wall degrading enzymes, such as chitinase, ß-l,3-glucanase, and protease, which caused cell wall lysis and hyphae deformation of P. maculans, leading to mycelial growth inhibition by 54.94%. Inoculation of B. velezensis CE 100 suppressed P. maculans infection and increased seedling survival rate by 1.6-fold and 1.3-fold compared to chemical fertilizer and control, respectively. In addition, B. velezensis CE 100 produced indole-3-acetic acid, which improved root development and nutrient uptake compared to chemical fertilizer and control. Especially, inoculation with B. velezensis CE 100 increased the total nitrogen content of Q. acutissima seedlings, improved the chlorophyll index in the leaves, and increased seedling biomass by 1.3-fold and 2.2-fold compared to chemical fertilizer and control, respectively. Thus, B. velezensis CE 100 could be applied in the eco-friendly production of high-quality forest seedlings.

Antifungal Activity of Bacillus velezensis CE 100 against Anthracnose Disease (Colletotrichum gloeosporioides) and Growth Promotion of Walnut (Juglans regia L.) Trees.

Walnut anthracnose caused by Colletotrichum gloeosporioides is a deleterious disease that severely affects the production of walnut (Juglans regia L.). The aim of this study was to assess the antifungal and growth promotion activities of Bacillus velezensis CE 100 as an alternative to chemical use in walnut production. The crude enzyme from B. velezensis CE 100 exhibited chitinase, protease, and ß-l,3-glucanase activity and degraded the cell wall of C. gloeosporioides, causing the inhibition of spore germination and mycelial growth by 99.3% and 33.6% at 100 µL/mL, respectively. The field application of B. velezensis CE 100 culture broth resulted in a 1.3-fold and 6.9-fold decrease in anthracnose disease severity compared to the conventional and control groups, respectively. Moreover, B. velezensis CE 100 produced indole-3-acetic acid (up to 1.4 µg/mL) and exhibited the potential for ammonium production and phosphate solubilization to enhance the availability of essential nutrients. Thus, field inoculation of B. velezensis CE 100 improved walnut root development, increased nutrient uptake, enhanced chlorophyll content, and consequently improved total biomass by 1.5-fold and 2.0-fold compared to the conventional and control groups, respectively. These results demonstrate that B. velezensis CE 100 is an effective biocontrol agent against anthracnose disease and a potential plant growth-promoting bacteria in walnut tree production.

The Role of Lysobacter antibioticus HS124 on the Control of Fall Webworm (Hyphantria cunea Drury) and Growth Promotion of Canadian Poplar (Populus canadensis Moench) at Saemangeum Reclaimed Land in Korea.

Populus canadensis Moench forests established in Saemangeum-reclaimed land have been invaded by Hyphantria cunea Drury, causing defoliation and stunted growth. This study investigated the biocontrol potential of cuticle degrading chitinase and protease secreted by Lysobacter antibioticus HS124 against H. cunea larvae. In addition, L. antibioticus HS124 was examined for indole-3-acetic acid phytohormone production for plant growth promotion. To determine the larvicidal activity in the laboratory experiments, crude enzymes, bacteria culture, CY medium, and water (control) were sprayed on the larvae reared on natural diet in insect rearing dishes. Treatment with crude enzymes and bacteria culture caused 76.7% and 66.7% larvae mortality, respectively. The larvae cuticle, mainly composed of chitin and proteins, was degraded by cuticle-degrading enzymes, chitinase, and protease in both the bacteria culture and crude enzyme treatments, causing swelling and disintegration of the cuticle. Field application of the bacteria culture was achieved by vehicle-mounted sprayer. Bacterial treatment caused morphological damage on the larvae cuticles and subsequent mortality. Foliar application of the bacteria culture reduced tree defoliation by H. cunea and enhanced growth compared to the control. Especially, L. antibioticus HS124 produced auxins, and increased growth of poplar trees.

Bacillus velezensis CE 100 Inhibits Root Rot Diseases (Phytophthora spp.) and Promotes Growth of Japanese Cypress (Chamaecyparis obtusa Endlicher) Seedlings.

Root rot diseases, caused by phytopathogenic oomycetes, Phytophthora spp. cause devastating losses involving forest seedlings, such as Japanese cypress (Chamaecyparis obtusa Endlicher) in Korea. Plant growth-promoting rhizobacteria (PGPR) are a promising strategy to control root rot diseases and promote growth in seedlings. In this study, the potential of Bacillus velezensis CE 100 in controlling Phytophthora root rot diseases and promoting the growth of C. obtusa seedlings was investigated. B. velezensis CE 100 produced ß-1,3-glucanase and protease enzymes, which degrade the ß-glucan and protein components of phytopathogenic oomycetes cell-wall, causing mycelial growth inhibition of P. boehmeriae, P. cinnamomi, P. drechsleri and P. erythoroseptica by 54.6%, 62.6%, 74.3%, and 73.7%, respectively. The inhibited phytopathogens showed abnormal growth characterized by swelling and deformation of hyphae. B. velezensis CE 100 increased the survival rate of C. obtusa seedlings 2.0-fold and 1.7-fold compared to control, and fertilizer treatment, respectively. Moreover, B. velezensis CE 100 produced indole-3-acetic acid (IAA) up to 183.7 mg/L, resulting in a significant increase in the growth of C. obtusa seedlings compared to control, or chemical fertilizer treatment, respectively. Therefore, this study demonstrates that B. velezensis CE 100 could simultaneously control Phytophthora root rot diseases and enhance growth of C. obtusa seedlings.

Antifungal Activity of Cyclic Tetrapeptide from Bacillus velezensis CE 100 against Plant Pathogen Colletotrichum gloeosporioides.

The aim of this study was to investigate the antifungal activity of a cyclic tetrapeptide from Bacillus velezensis CE 100 against anthracnose-causing fungal pathogen Colletotrichum gloeosporioides. Antifungal compound produced by B. velezensis CE 100 was isolated and purified from ethyl acetate extract of B. velezensis CE 100 culture broth using octadecylsilane column chromatography. The purified compound was identified as cyclo-(prolyl-valyl-alanyl-isoleucyl) based on mass spectrometer and nuclear magnetic resonance analyses. This is the first report of the isolation of a cyclic tetrapeptide from B. velezensis CE 100 culture filtrate. Cyclic tetrapeptide displayed strong antifungal activity at concentration of 1000 µg/mL against C. gloeosporioides mycelial growth and spore germination. Our results demonstrate that the antifungal cyclic tetrapeptide from B. velezensis CE 100 has potential in bioprotection against anthracnose disease of plants caused by C. gloeosporioides.

FDTD analysis of the light extraction efficiency of OLEDs with a random scattering layer.

The light extraction efficiency of OLEDs with a nano-sized random scattering layer (RSL-OLEDs) was analyzed using the Finite Difference Time Domain (FDTD) method. In contrast to periodic diffraction patterns, the presence of an RSL suppresses the spectral shift with respect to the viewing angle. For FDTD simulation of RSL-OLEDs, a planar light source with a certain spatial and temporal coherence was incorporated, and the light extraction efficiency with respect to the fill factor of the RSL and the absorption coefficient of the material was investigated. The design results were compared to the experimental results of the RSL-OLEDs in order to confirm the usefulness of FDTD in predicting experimental results. According to our FDTD simulations, the light confined within the ITO-organic waveguide was quickly absorbed, and the absorption coefficients of ITO and RSL materials should be reduced in order to obtain significant improvement in the external quantum efficiency (EQE). When the extinction coefficient of ITO was 0.01, the EQE in the RSL-OLED was simulated to be enhanced by a factor of 1.8.

Impact of Clopidogrel loading dose in patients with chronic kidney disease undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction.

The optimal loading dose of clopidogrel in patients with chronic kidney disease who undergo primary percutaneous coronary intervention for ST-segment elevation myocardial infarction has not been investigated. The aim of this study was to assess the impact of clopidogrel loading dose on clinical outcomes in this setting. A total of 1,457 patients with CKD (estimated glomerular filtration rate <60 ml/min/1.73 m(2)) were evaluated according to clopidogrel loading dose: 600 mg (n = 861) versus 300 mg (n = 596). In-hospital complications, including major bleeding and clinical outcomes at 1 and 12 months, were compared between the 2 groups. The in-hospital major bleeding rate was similar (0.8% vs 0.2%, p = 0.09). Also, there were no differences in major adverse cardiac event rates, including death, recurrent myocardial infarction, target lesion revascularization, and stent thrombosis, at 1 month (15.6% vs 16.4%, p = 0.70) and 12 months (19.0% vs 21.3%, p = 0.32). On multivariate analysis, a 600-mg loading dose of clopidogrel was not an independent predictor of 1-month (odds ratio 1.13, 95% confidence interval 0.49 to 2.57, p = 0.78) and 12-month (odds ratio 0.89, 95% confidence interval 0.52 to 1.51, p = 0.66) major adverse cardiac events. After propensity score-matched analysis, these results were unchanged. In conclusion, a 600-mg loading dose of clopidogrel was not effective in reducing 1- and 12-month major adverse cardiac events in patients with chronic kidney disease who underwent primary percutaneous coronary intervention for ST-segment elevation myocardial infarction, but this dose did not increase the in-hospital major bleeding rate.

Decreased Glomerular Filtration Rate is an Independent Predictor of In-Hospital Mortality in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention.

BACKGROUND AND OBJECTIVES: Patients with renal dysfunction (RD) experience worse prognosis after myocardial infarction (MI). The aim of the present study was to investigate the impact of admission estimated glomerular filtration rate (eGFR) on clinical outcomes of patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation MI (STEMI). SUBJECTS AND METHODS: We retrospectively evaluated 4,542 eligible patients from the Korea Acute Myocardial Infarction Registry (KAMIR). Patients were divided into three groups according to eGFR (mL/min/1.73 m(2)): normal renal function (RF) group (eGFR ≥60, n=3,515), moderate RD group (eGFR between 30 to 59, n=894) and severe RD group (eGFR <30, n=133). Baseline characteristics, angiographic and procedural results, and in-hospital outcomes between the three groups were compared. RESULTS: Age, gender, Killip class ≥3, hypertension, diabetes, congestive heart failure, peak creatine kinase-MB, high sensitivity C-reactive protein, B-type natriuretic peptide, left ventricle ejection fraction, multivessel disease, infarct-related artery and rate of successful PCI were significantly different between the 3 groups (p<0.05). With decline in RF, in-hospital complications developed with an increasing frequency (14.1% vs. 31.8% vs. 45.5%, p<0.0001). In-hospital mortality rate was significantly higher in the moderate and severe RD groups as compared to the normal RF group (2.3% vs. 13.9% vs. 25.6%, p<0.0001). Using multivariate logistic regression analysis, adjusted odds ratio for in-hospital mortality was 2.67 {95% confidence interval (CI) 1.44-4.93, p=0.002} in the moderate RD group, and 4.09 (95% CI 1.48-11.28, p=0.006) in the severe RD group as compared to the normal RF group. CONCLUSION: Decreased admission eGFR was associated with worse clinical courses and it was an independent predictor of in-hospital mortality in STEMI patients undergoing primary PCI.

[A case of hemophagocytic syndrome with terminal ileal ulcerations].

Reactive hemophagocytic syndrome or hemophagocytic lymphohistiocytosis, is characterized by the proliferation of benign histiocytes showing phagocytosis of blood cells in hematopoietic organs including bone marrow, spleen, or lymph nodes, accompanied by fever, hepatosplenomegaly, hepatic dysfunction, pancytopenia, and hypertriglyceridemia. The pathogenesis of reactive hemophagocytic syndrome is unknown. It is often associated with infection, malignant neoplasm, autoimmune disease, drugs and various immunodeficiencies. The prognosis of this syndrome is poor and the causes of death are hemorrhage, infection, or multiorgan failure. We experienced a case of hemophagocytic syndrome with terminal ileal ulcers, not associated with other causes. Thus, we report this case with a review of literatures.