• The Plant Pathology Journal
• /
• v.26 no.2
• /
• pp.154-158
• /
• 2010

Early nematode development and subcellular responses in resistant soybean lines PI 88788 and PI 437654 infected with races 3 (R3) and 14 (R14) of soybean cyst nematode (SCN), Heterodera glycines Ichinohe, were compared. SCN R14 nematodes penetrated and developed significantly more than R3 at 5-6 days after inoculation. Both races also penetrated and developed more in PI 88788 than in PI 437654. Syncytia, characterized by cell wall dissolution and cellular hypertrophy, were developed more in PI 88788 than in PI 437654 and more by R14 than R3, for which less necrotic responses occurred in the former than the latter. This suggests that the latter two may be more resistant and less virulent than the former two, respectively. A common structural feature found in each of PI 437654 and PI 88788 in relation to SCN-resistance was the formation of prominent cell wall appositions and nuclear degeneration prior to cytoplasmic degradation in syncytial cells, respectively. Necrosis and cell wall apposition are types of hypersensitive responses occurring at early stages of the nematode infection so that these structural modifications indicate the inhibition of initial syncytial development related to the early nematode development. As soybean cultivars and lines with identical or similar genotypes have the same types of structural features related to SCN-resistance, the structural modifications induced by SCN infection may result from the expression of inheritable resistance genes, of which the information can be used for breeding soybean cultivars and lines specifically resistant to SCN races.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.1
• /
• pp.122-126
• /
• 2004

A digestion trial in vitro was conducted to study effects of supplementation of NSP (non-starch polysaccharides) degrading enzyme (feed grade) on cell wall degradation and digestibility of nutrients in barley. The slices of barley were soaked in distilled water with or without 0.15% non-starch polysaccharides degrading enzyme. Microscopic examination of the slices showed that the endosperm cell wall of barley was completely degraded by the non-starch polysaccharides degrading enzyme. The residues and supernatant of digesta in vitro were separated by filtration with 0.1 mm nylon fabric. The residues were used for measurement of crude protein, crude fat, crude fiber, and moisture. The supernatant was used for determination of viscosity, as well as amino-nitrogen and glucose content. The results showed that compared with the control, the amino-nitrogen and glucose content of the supernatant increased by 17.58% (p<0.05) and 10.26% (p<0.05), respectively, while viscosity did not change. Enzyme supplementation increased the digestibilities of dry matter, crude protein, nitrogen-free extract, crude fat and crude fiber of barley by 18.1% (p<0.05), 20.3% (p<0.05), 16.4% (p<0.05), 26.9% (p<0.05) and 30.0% (p<0.05), respectively. The present study suggests that cell wall hydrolysis may contribute to improved nutrient digestion in vivo when non-starch polysaccharides degrading enzymes are fed to swine.

• The Korean Journal of Mycology
• /
• v.38 no.1
• /
• pp.21-24
• /
• 2010

This study was carried out to select cell wall degrading enzymes for maximizing protoplast yield from Basidiomycetes. The protoplasts were released from spore suspension, mycelia cultured on cellophane membrane, and homogenized mycelia of Flammulina velutipes using commercial cell wall degrading enzymes. The highest yield of protoplasts was obtained from the homogenized mycelia treated with the enzyme combination of $Glucanex^R$ 200G and cellulase onozuka R-10. The protocol was also available for Pleurotus ostreatus, P. eryngii, and Hypsizygus marmoreus.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.6
• /
• pp.1157-1162
• /
• 2017

The goal of this study was to identify and characterize selected Trichoderma isolates by metabolic profiling and enzyme assay for evaluation of their potential as biocontrol agents against plant pathogens. Trichoderma isolates were obtained from the Rural Development Administration Genebank Information Center (Wanju, Republic of Korea). Eleven Trichoderma isolates were re-identified using ribosomal DNA internal transcribed spacer (ITS) regions. ITS sequence results showed new identification of Trichoderma isolates. In addition, metabolic profiling of the ethyl acetate extracts of the liquid cultures of five Trichoderma isolates that showed the best anti-Phytophthora activities was conducted using gas chromatography-mass spectrometry. Metabolic profiling revealed that Trichoderma isolates shared common metabolites with well-known antifungal activities. Enzyme assays indicated strong cell wall-degrading enzyme activities of Trichoderma isolates. Overall, our results indicated that the selected Trichoderma isolates have great potential for use as biocontrol agents against plant pathogens.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.2
• /
• pp.186-188
• /
• 1999

This study was conducted to investigate the effects of four levels (0, 10, 20, 40 %) of sugar-beet pulp (SB pulp) supplementation to Italian ryegrass hay (IRG hay) on the fiber degradability of IRG hay in the rumen of goats. The following results were obtained: Degradabilities of DM, NDF, ADF and hemicellulose of IRG hay in the rumen increased significantly (p<0.05) by 10 % level supplementation of SB pulp to IRG hay. This was probably due to the increased numbers (p<0.05) of total viable bacteria, pectin-fermenting, xylan-fermenting and cellulolytic bacteria in the rumen in the increased supply of degradable pectic substances and hemicellulose at 10% level supplementation of SB pulp pectin. In 40% supplementation of SB pulp, ruminal pH was lowered by the fermentation of increased amount of molasses from SB pulp, resulting in the depression of growth of fiber fermenting bacteria and hence the decrease in degradabilities of cell wall fractions. It was suggested from this study that the sugar-beet pulp supplementation to forages at the level of 10% in the total diet increased fiber degradation of forage in the rumen of goats.

• Journal of Microbiology and Biotechnology
• /
• v.33 no.12
• /
• pp.1615-1624
• /
• 2023

Microcystis blooms threaten ecosystem function and cause substantial economic losses. Microorganismbased methods, mainly using cyanobactericidal bacteria, are considered one of the most ecologically sound methods to control Microcystis blooms. This study focused on gaining genomic insights into Paucibacter aquatile DH15 that exhibited excellent cyanobactericidal effects against Microcystis. Additionally, a pan-genome analysis of the genus Paucibacter was conducted to enhance our understanding of the ecophysiological significance of this genus. Based on phylogenomic analyses, strain DH15 was classified as a member of the species Paucibacter aquatile. The genome analysis supported that strain DH15 can effectively destroy Microcystis, possibly due to the specific genes involved in the flagellar synthesis, cell wall degradation, and the production of cyanobactericidal compounds. The pan-genome analysis revealed the diversity and adaptability of the genus Paucibacter, highlighting its potential to absorb external genetic elements. Paucibacter species were anticipated to play a vital role in the ecosystem by potentially providing essential nutrients, such as vitamins B₇, B₁₂, and heme, to auxotrophic microbial groups. Overall, our findings contribute to understanding the molecular mechanisms underlying the action of cyanobactericidal bacteria against Microcystis and shed light on the ecological significance of the genus Paucibacter.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.12
• /
• pp.2119-2128
• /
• 2017

Citrinin (CIT) is a toxic secondary metabolite produced by fungi belonging to the Penicillium, Aspergillus, and Monascus spp. This toxin has been detected in many agricultural products. In this study, a strain Y3 with the ability to eliminate CIT was screened and identified as Cryptococcus podzolicus, based on the sequence analysis of the internal transcribed spacer region. Neither uptake of CIT by cells nor adsorption by cell wall was involved in CIT elimination by Cryptococcus podzolicus Y3. The extracellular metabolites of Cryptococcus podzolicus Y3 stimulated by CIT or not showed no degradation for CIT. It indicated that CIT elimination was attributed to the degradation of intracellular enzyme(s). The degradation of CIT by C. podzolicus Y3 was dependent on the type of media, yeast concentration, temperature, pH, and initial concentration of CIT. Most of the CIT was degraded by C. podzolicus Y3 in NYDB medium at 42 h but not in PDB medium. The degradation rate of CIT was the highest (94%) when the concentration of C. podzolicus Y3 was $1{\times}10^8cells/ml$. The quantity of CIT degradation was highest at $28^{\circ}C$, and there was no degradation observed at 3$5^{\circ}C$. The study also showed that acidic condition (pH 4.0) was the most favorable for CIT degradation by C. podzolicus Y3. The degradation rate of CIT increased to 98% as the concentration of CIT was increased to $20{\mu}g/ml$. The toxicity of CIT degradation product(s) toward HEK293 was much lower than that of CIT.

• Korean Journal Plant Pathology
• /
• v.14 no.5
• /
• pp.386-392
• /
• 1998

Reproduction of the soybean cyst nematode (SCN), Heterodera glycines Ichinohe on the susceptible soybean cultivar, Lee 74, was significantly reduced by pre-, post- and simultaneous treatments of acetylsalicylic acid (ASA, aspirin). The control efficiencies were 60%, 64% and 87% for pre-, post- and simultaneous treatments, respectively. ASA had no significant effect on the survival of 2nd stage juveniles and their penetration into the soybean root tissues, but significantly inhibited the early stage nematode growth in the roots. Syncytia were formed 2∼3 days after inoculation in the susceptible soybean without ASA treatment, characterized by dense cytoplasm and increased cellular organelles such as mitochondria and endoplasmic reticulum. The nematode stylet was penetrated into the syncytial cell, and feeding tube was formed at the nematode stylet was penetrated into the syncytial cell, and feeding tube was formed at the nematode stylet entry. However, in the ASA treatments, syncytium was not formed or degenerated, depending on the root tissues. In the pre-treatments of ASA, nematode stylets did not penetrate into cells, showing callose-like cell wall thickening formed at the nematode probing sites, or retracted from the infected cells. The stylet penetration sites of syncytial cells appeared to be sealed off with fibrillar materials. With post-treatment of ASA, syncytia formed by the nematode were degenerated, characterized by degradation of syncytial cytoplasm.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1998.11a
• /
• pp.172-173
• /
• 1998

A research collection of Pseudomons solanacearum bacteria, a pathogen causing ‘bacteria wilt’ disease of more than 265 plant species, represented for northern provinces of Vietnam has recently been established and was saved for examination of antifungal activity in their culture fluids. All strains used in this work have been isolated from infected tomato, potato, and groundnut collected from production fields and they express different levels of virulence on their host plants. Cell-free culture fluids of these strains were tested for antifungal activity (to inhibit growth of mycelium and to destroy germination tube of fungal spores) on a number of fungi that either infect or associate with vegetable crops of Solanaceae family (tomato, potato, pepers...), fruit plants (banana), and even well-known by Vietnamese traditional medicine herbal plants belonging to Trifoliatus, Schefflera, Homalomena and Panax genera (Araliaceae family) of which roots are used as a resource of the herbal material. The antifungal activity was found in nearly all strains tested. Result of study on chitin, CMC, tween 80 and casein degradation abilities of the latter suggested that antifungal activity of positively-found strains may be due to their ability of extracelluar chitinase's excretion that destroy fungal cell wall.

• Conservation Science in Museum
• /
• v.2
• /
• pp.27-34
• /
• 2000

24 wooden objects excavated from Daho-ri were identified into 8 categories such as Quercus spp. (37.7%), Castanea crenata (8.3%), Prunus (8.3%), Ilex (4.1%), Alnus spp. (25%), Prunus spp. (4.1%), Zelkova serrata (4.1%) and Fraxinuse (8.3%). Physical properties of the above high water content, high contraction rate and significant density reduction. As for degradation pattern, observation with polarizing microscope showed significant decrease of double reflection phenomenon in most of the excavated objects excluding vessel compared to other kinds of objects, and observation with SEM showed remarkable degradation of organization structure including the 2nd cell wall of wood. Reagent can be easily penetrated and diffused into the objects with high degradation rate, so it's beneficial to treat them with polymers such as PEG#4000(MW:3,350), but in order to prevent contraction and change in shape, high concentration of Reagent is required in treatment to hold wood organization structure.