• Microbiology and Biotechnology Letters
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• v.10 no.4
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• pp.245-252
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• 1982

The enzymes lytic to red yeast cell wall, which were produced by Penicillium lilacinum ATCC 36010 and Bacillus pumilus No 41, hydrolyzed an extracellular mannan from Rhodotonla glutinis IFO 0695. mannan was arranged with $\beta$-1,3 and $\beta$-1,4 linkages alternatively. Using this mannan, substrate specificities of these enzymes were investigated. The one from Penicillium lilacinum was an unique mannanase which hydrolyzed $\beta$-1,3 mannoside bond and the other from B. pumilus was a new type of mannanase which cleaved $\beta$-1,4 mannoside bond with requirement of the existence of $\beta$-1,3 linkage on the reducing side. Both enzymes released two kinds of oligosaccharide from mannan, respectively. However, the enzyme from Pen lilacinum produced tetrasaccharide and disaccharide and one of them, tetrasaccharide, was hydrolyzed to disaccharide further. The one from B. pumilus released tetrasaccharide and hexasaccharide from mannan finally.

• The Plant Pathology Journal
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• v.31 no.1
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• pp.50-60
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• 2015

The use of novel isolates of Trichoderma with efficient antagonistic capacity against Fusarium oxysporum f. sp. lycopersici (FOL) is a promising alternative strategy to pesticides for tomato wilt management. We evaluated the antagonistic activity of 30 isolates of T. asperellum against 4 different isolates of FOL. The production of extracellular cell wall degrading enzymes of the antagonistic isolates was also measured. The random amplified polymorphic DNA (RAPD) method was applied to assess the genetic variability among the T. asperellum isolates. All of the T. asperellum isolates significantly reduced the mycelial growth of FOL isolates but the amount of growth reduction varied significantly as well. There was a correlation between the antagonistic capacity of T. asperellum isolates towards FOL and their lytic enzyme production. Isolates showing high levels of chitinase and ${\beta}$-1,3-glucanase activities strongly inhibited the growth of FOL isolates. RAPD analysis showed a high level of genetic variation among T. asperellum isolates. The UPGMA dendrogram revealed that T. asperellum isolates could not be grouped by their antagonistic behavior or lytic enzymes production. Six isolates of T. asperellum were highly antagonistic towards FOL and potentially could be used in commercial agriculture to control tomato wilt. Our results are consistent with the conclusion that understanding the genetic variation within Trichoderma isolates and their biochemical capabilities are required for the selection of effective indigenous fungal strains for the use as biocontrol agents.

• Korean Journal of Microbiology
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• v.33 no.4
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• pp.242-246
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• 1997

The protein profile of Synechococcus sp. cyanophage was investigated employing SDS-PAGE. The phage appears to be composed of two major proteins of 97 and 52 kDa and at least seven minor proteins of 70, 65, 60, 40, 35, 28, and 6 kDa. It seems that each subunit is combined to form a multimer although any disulfide bond does not exist in the phage structure. Lytic activity of the phage particle against cell wall was detected around the 52 kDa on renaturing SDS-PAGE using heat-killed Micrococcus luteus cells as substrate. The activity has the optimal pH between 9 and 10, and slightly inhibited by EDTA.

• Korean Journal of Microbiology
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• v.40 no.1
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• pp.54-59
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• 2004

$\beta$-Glucan has been efficiently produced with higher yield by the optimization of liquid cultivation conditions. The optimal composition of medium for batch culture was 5% (w/v) of glucose as a carbon source, 0.5% (w/v) of yeast and 0.5% (w/v) of malt extract as a nitrogen source, 0.1% (w/v) of $KH_2PO_4$ and 0.05% (w/v) $MgSO_4{\cdot}7H_2O$, which had been the base medium for determination of other conditions. The set-up conditions are pH 5.0, $28^{\circ}C$, 1 vvm for aeration and 300 rpm for agitation. In order to minimize the inhibition effect of glucose on the initial growth of mycelia and to maximize the production of extracellular $\beta$-glucan, we have reduced the initial glucose feed to 4% and added 2nd feed at the point of 70 hr from the initial feed. The 2nd feed was composed of glucose 3%, yeast extract 0.1 % and malt extract 0.1 %. It improved the $\beta$-glucan yield upto 5.2 g/L in comparison with 2.8 g/L resulted from batch cultivation. Moreover, the serial treatment of a cell wall lytic enzyme and bromelain to the mycelia was effective for extraction of the cell wall bound $\beta$-glucan. The yield of $\beta$-glucan extraction by the enzyme treatment was 3.5 g/L, which was almost 4 times higher than that by hot-water extraction.

• Applied Microscopy
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• v.13 no.1
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• pp.49-61
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• 1983

Protoplast releasing mechanisms from Trichoderma koningii, fine structures of the released protoplsts, and their regeneration mode were studied by scanning and transmission electron microscopy. Two types of protoplast releasing mechanisms were observed. In one mechanism, cytoplasm emerged through a cell wall pore developed by cell lytic enzymes and formed a spherical protoplast. In the other mechanism, as the cell wall became progressively thinner, the inner cytoplasm partially rounded to form nonspherical bodies which became spherical protoplasts after being released into the enzyme solution. But, these two types of protoplast releasing mechanisms did not seem to be. mutually exclusive but could occur on the same mycelium simultaneously. And it appeared that cytoplasm which did not become a protoplast by the first mechanism could from a protoplast by the second mechanism. The preparations contained two types of protoplasts, released from different sites of the mycelia. Those released from younger mycelia had dense cytoplasm and small vesicles. Those released from the older mycelia had less dense cytoplasm and larger vacuoles. In the case of regeneration, before producing normal mycelia, most of the protoplasts assumed aberrant tube and yeast-like-forms. Normal mycelia were produced at the end of the yeastlike-forms and sometimes in the middle of the aberrant tube.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.550-555
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• 2008

An efficient production method of spirulina extract was developed by enzymatic treatment using proteolytic enzymes. The suitable dosage of Tunicase, a cell lytic enzyme, was used to be 2.0% (w/w). To maximize solid recovery and spirulina extraction (SE) index, which indicates nucleic acid-related substances content, the dosage of Alcalase, commercially available pretense, was found to be 1.0% (w/w). By simultaneous treatments using optimal dosages of Tunicase and Alcalase, the highest SE index and solid recovery were obtained. The SE index and solid recovery of simultaneous treatments were notably enhanced by 100% ($11.4%\;{\rightarrow}\;22.8%$) and 56% ($45.2%\;{\rightarrow}\;70.7%$), respectively, than those of the non-treated extracts.

• Korean Journal Plant Pathology
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• v.3 no.2
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• pp.124-130
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• 1987

The optimum conditions for protoplast formation and regeneration from Pyricularia oryzae Cav. were selected as follows. As a basic solution, 0.02M potassium phosphate buffer solution plus 0.6M KCl adjusted to pH 5.2 with 1N HCl was used. A mixture of enzyme combinations with 20mg Cellulase R-l0/ml, 5mg Macerozyme R-l0/ml and l0mg Driselase/ml used as a lytic enzyme showed better lytie effect than any single enzyme treatment for protoplast formation. Two-day-old mycelia of P. oryzae grown in the mixture of three lytie enzyme solution at $30^{\circ}C$ for 3 hr showed best condition for protoplasts formation. For regeneration from the protoplasts of P. oryzae, potato dextrose agar containing 0.02M potassium phosphate plus 0.6M KCl used as a stabilizer was best for regeneration medium.

• KSBB Journal
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• v.24 no.6
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• pp.598-601
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• 2009

Perilla [Perilla frutescens (L.) Britt] seedlings are easy to grow and eaten as the health vegetable sprout. Two day old perilla seedlings since germination were given a mild wounding using cell wall lytic NaOH/SDS solution for infiltration with recombinant Agrobacterium cells treated with phenolic compounds. In the analysis of fluorometric GUS gene expression for the transformed perilla seedlings, GUS enzyme activity was the highest by the combined treatments of 50 mM acetosyringone and 0.5% NaOH solution containing 0.01% SDS implying a synergic effect. This result could be successfully applied for demonstrating hepatitis B virus antigen (HBsAg) protein expression.

• IMMUNE NETWORK
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• v.6 no.4
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• pp.179-184
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• 2006

Background: Identification of antigen-specific T cells has yielded valuable information on pathologic process and the disease state. Assays for quantification of inflammatory cytokines or lytic-granule molecules have been generally used to evaluate antigen specific T cell response, however their applicability have been hampered due to the limited source of autologous antigen-presenting target cells (APC). Methods: K562, a leukemic cell line deficient of human leukocyte antigen (HLA), was transfected with a gene encoding HLA-A*02 (K562/ A*02) and its function as stimulator cells in inducing activation of HLA-matched T cells was evaluated by IFN-${\gamma}$ enzyme linked immunospot (ELISPOT) assay. Results: The stable transfectant K562/ A*02 pulsed with HLA- A*02 restricted peptide could specifically induce IFN-${\gamma}$ secretion by CD8+ T cells compared to no detectable secretion by CD4+ T cells. However, CD56+ NK cells secreted IFN-${\gamma}$ in both K562/ A*02 with peptide and without peptide. The number of IFN-${\gamma}$ secreted CD8+ T cells was increased according to the ratio of T cells to K562 and peptide concentration. Formalin-fixed K562/ A*02 showed similar antigen presenting function to live K562/ A*02. Moreover, K562/ A*02 could present antigenicpeptide to not only A*0201 restricted CD8+ T cells but also CD8+ T cells from A*0206 donor. Conclusion: These results suggest that K562/ A*02 could be generally used as target having specificity and negligible background for measuring CD8+ T cell responses and selective use of K562 with responsder matched HLA molecules on its surface as APC may circumvent the limitation of providing HLA-matched autologous target cells.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.2
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• pp.105-111
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• 2013

The experiments were carried out to investigate the biocontrol potential of Lysobacter capsici YS1215 on root-knot nematode and to characterize its lytic enzyme activities. L. capsici YS1215 showed chitinase and gelatinase activities on the medium containing 0.5% chitin or 0.5% gelatin as substrates. Cell growth of L. capsici YS1215 was highest at 6 days, and the highest activities of chitinase (4.0 unit $ml^{-1}$) and gelatinase (7.43 unit $ml^{-1}$) were observed on 3 and 5 days after incubation, respectively. To investigate the effect of L. capsici YS1215 on tomato growth and nematode infection, the plants in pot trial were treated with bacterial culture (BC), half of bacterial culture (HBC), only bacterial medium (BM), tap water (TW) and commercial nematicide (CN). HBC treatd plants showed the higher shoot fresh weight and dry weight on $5^{th}$week after incubation while BM, HBC and BC had consistently higher values than TW at $9^{th}$ week. HBC appeared to be the highest shoot fresh length at $9^{th}$ week. Both CN and BC showed lower number of egg mass, root gall, and population of juveniles in soil compared to BC, HBC, BM and TW. These results suggest that L. capsici YS1215 with its strong ability of lytic enzyme production can be one of the most significant candidates for biocontrol agents against root-knot nematodes.