• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.745-752
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• 2007

A $\beta$-glucosidase from the algal lytic bacterium Sinorhizobium kostiense AFK-13, grown in complex media containing cellobiose, was purified to homogeneity by successive ammonium sulfate precipitation, and anion-exchange and gel-filtration chromatographies. The enzyme was shown to be a monomeric protein with an apparent molecular mass of 52 kDa and isoelectric point of approximately 5.4. It was optimally active at pH 6.0 and $40^{\circ}C$ and possessed a specific activity of 260.4 U/mg of protein against $4-nitrophenyl-\beta-D-glucopyranoside$(pNPG). A temperature-stability analysis demonstrated that the enzyme was unstable at $50^{\circ}C$ and above. The enzyme did not require divalent cations for activity, and its activity was significantly suppressed by $Hg^{+2}\;and\;Ag^+$, whereas sodium dodecyl sulfate(SDS) and Triton X-100 moderately inhibited the enzyme to under 70% of its initial activity. In an algal lytic activity analysis, the growth of cyanobacteria, such as Anabaena flos-aquae, A. cylindrica, A. macrospora, Oscillatoria sancta, and Microcystis aeruginosa, was strongly inhibited by a treatment of 20 ppm/disc or 30 ppm/disc concentration of the enzyme.

• Bulletin of the Korean Chemical Society
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• v.18 no.7
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• pp.761-766
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• 1997

Phospholipase C from Clostridium perfringens is known to catalyze the hydrolysis of phospholipids in biological membranes. In this study, a simple and sensitive method for assaying phospholipase C was developed by using liposomes entrapping calcein as a fluorescent marker. Phospholipase C-induced lysis of liposomes was determined by measuring the fluorescence intensity of calcein released out from liposomes, Various liposomes with different compositions were prepared by reverse-phase evaporation method to investigate the effect of liposomal composition on the lytic activity of phospholipase C. The calcein-entrapping efficiency of liposomes was affected by the chain length of fatty acid in phosphatidylcholine constituting liposomes. The lytic activity of phospholipase C was the highest against liposomes prepared with eggPC. The lytic activity decreased with increasing chain length of fatty acid in phosphatidylcholine. Incorporation of cholesterol more than 20% into the liposomal bilayer inhibited the phospholipase C-induced lysis. The lysis of liposomes was more greatly increased by the addition of 10 mM of calcium. The lytic activity of phospholipase C was also affected by the surface charge of liposomes. Taken together, it was concluded that reverse-phase evaporation vesicles composed of dipalmitoylphosphatidylcholine and cholesterol in the molar ratio of 9 : 1 allowed to detect the lowest concentration of phospholipase C (0.10 μg/assay volume). This study suggested that the use of liposomes can provide a simple, sensitive and inexpensive method for assaying phospholipase C.

• Food Science and Preservation
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• v.30 no.1
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• pp.42-51
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• 2023

This study aimed to characterize a lytic Salmonella Typhimurium-specific (ST) phage and its biofilm control capability against S. Typhimurium biofilm on polypropylene surface. ST phage was isolated, propagated, and purified from water used in a slaughterhouse. The morphology of ST phage was observed via transmission electron microscopy. Its bactericidal effect was evaluated by determining bacterial concentrations after the phage treatment at various multiplicities of infection (MOIs) of 0.01, 1.0, and 100. Once the biofilm was formed on the polypropylene tube after incubation at 37℃ for 48 h, the phage was treated and its antibiofilm capability was determined using crystal violet staining and plate count method. The phage was isolated and purified at a final concentration of ~11 log PFU/mL. It was identified as a myophage with an icosahedral head (~104 nm) and contractile tail (~90-115 nm). ST phage could significantly decrease S. Typhimurium population by ~2.8 log CFU/mL at an MOI of 100. After incubation for 48 h, biofilm formation on polypropylene surface was confirmed with a bacterial population of ~6.9 log CFU/cm². After 1 h treatment with ST phage, the bacterial population in the biofilm was reduced by 2.8 log CFU/cm². Therefore, these results suggest that lytic ST phage as a promising biofilm control agent for eradicating S. Typhimurium biofilm formed on food contact surfaces.

• Journal of fish pathology
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• v.11 no.2
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• pp.137-141
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• 1998

Temperate phages were effectively induced from presumptive lysogenized cells of 96 strains out of 111 strains of L. garvieae No. 44 strains (phage type B) as the host cell. Similar cultures in distilled water-based TSB did not induce lytic infection in these cells. These temperate phages were also effectively induced by ultraviolet irradiation. All phages isolated were lytic only to L. garvieae No. 44 strain and the lytic nature was different from those of PLgY, PLgW, and PLgS. The virions appeared extracellularly after 1h of induction culture and increased in number until reaching the maximum of $10^6$ PFU/ml after 12h. This phage production was lower than that ($10^{10}$ PFU/ml) of the virulent phage.

• Korean Journal of Microbiology
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• v.35 no.3
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• pp.231-236
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• 1999

The fuugus(Penicil1ium oralicum; HCLF-34) secreted the cyanobacteria lytic enzyme which had a molecular weight of about 22 kDa, a optimum temperature of $20^{\circ}C$, a optimum pH of 3.5, and a temperature-stable up to $50^{\circ}C$. The chemical ions such as sodium, potassium, barium, magnesium. and mangan ions appeared positive activity. but calcium, iron, copper ions, EDTA, and PMSF displayed negative activity: this results were the same as the characterilics of other cell wall lytic enzymes. This extracellular enzyme showed lytic aclivily against SDS-insoluble peptidoglycan of Anabaenrr cylinrlrica. The cell wall lylic enzyme of Penicilliurn oxalicum(HCLF-34) seemed to be glycosidase-like enzyme in the fact that ihe concentration of rcducing sugar was increased when the peptidoglycan of Anabaena qlinrlricn md Micrococcus luteus reacted with this enzyme

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.6 no.2
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• pp.13-22
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• 2011

Objectives : The purpose of this study is to find out the characteristics of intervertebral disc changes and relative factors of the spondylolisthesis patients in fifties by type of spondylolisthesis. Methods : We investigated 69 cases of patients who visited one Korean traditional medicine hospital and were diagnosed as spondylolisthesis on L-spine X-ray and L-spine magnetic resonance imaging(MRI). We selected 37 lytic spondylolisthesis patients and 32 degenerative spondylolisthesis patients. We analysed the relativity between the numbers of changed discs, types of changed disc, locations of nerve compression and types of spondylolisthesis. Results : 1. The number of changed discs increase in lytic type, but there is no statistically significant difference. 2. Bulging disc is the dominant type of disc change. There is no significant difference between two types. 3. Both foraminal type was shown dominantly in lytic spondylolisthesis, diffuse type in degenerative spondylolisthesis by the analysis of the location of the nerve compression. But the symptoms of patients and dermatome did not match in most of the cases. Conculsions : The direction of nerve compression is different while the disc changing aspects are similar in both types. In several spondylolisthesis patients in fifties, symptoms of patient are related to degeneration of vertebrae, not to the type of spondylolisthesis.

• Korean Journal of Microbiology
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• v.37 no.1
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• pp.15-20
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• 2001

In this study, we have isolated bacterial cell wall lytic enzyme in the culture supernatant of Aspergillus sp. HCLF-4. This hydrolase showed cell wall lytic activity against Anabaena cylindrica. The extracellular enzyme was produced by Aspergillus sp. HCLF-4 when it was grown in a PDB media containing 0.05% heat killed Micrococcus luteus cells. The molecular weight of lytic enzyme was about 14.3 kDa. The optimal pH and temperature for the activity of this enzyme were 3.0~4.0 and $30^{\circ}C$, respectively. This hydrolase activity was reduced by $Na^{+}$, $Li^{+}$, $Ca^{2+}$, $Cu^{2+}$, $Fe^{3+}$, EDTA, and PMSF, whereas it was increased by $Mg^{2+}$, $Mn^{2+}$>. The enzyme has N-acetylmuramyl-L-amidase or endopeptidase activity.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.1021-1027
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• 1997

We examined some properties of yeast cell wall lytic enzyme produced by Dicyma sp. YCH-37. Several metal ions, reducing reagents, and chemical modifiers have little effects on the lytic activity, except guanidine-HCl. Yeast cells of early log phase were more susceptible to the enzyme than those of stationary phase, and heat-treated cells were more easily lysed than intact living ones. Yeast cells pretreated with organic solvents such as butanol and acetone were more susceptible to the enzyme than intact living ones. Yeast cells cultured in Yeast extract-Malt extract medium containing 0.5 M ammonium sulfate were easily lysed by the lytic enzyme, and yeast cells cultured without shaking were more easily lysed by the enzyme than those with shaking. When SDS, ${\beta}-mercaptoethanol$, Triton X-100, sodium sulfite, and KCl were added to enzyme reaction mixture each, lysis of yeast cells was more effective.

• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.143-148
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• 1996

Thousand actinomycetes and 50 soil samples were used for the isolation of microorganisms producing yeast cell wall lytic enzymes. Among 493 strains producing large clear zones on autolysed washed yeast (AWY), 117 strains were selected on living yeast cell agar plates. With the method of lytic activity, one strain (St-1702) was selected, which was temporarily identified as Streptomyces eurythermus. The optimal condition for enzyme production of this strain was partially determined as follows: incubation of the strain for 3 days at 30$\circ$C in the medium containing 2% freeze dried yeast cell, 1% glucose, 1% K$_{2}$HPO$_{4}$, 0.01% MgSO$_{4}$'7H$_{2}$O, 0.5% peptone, and 0.2% (NH$_{4}$)$_{2}$CO$_{3}$ with pH 7.0. The protoplast formation of yeast by using the enzyme produced by this strain was compared with commercial enzymes.

• Korean Journal of Microbiology
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• v.21 no.4
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• pp.213-220
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• 1983

Conditions for isolation of protoplasts from conidiospores of Trichoderma koningii ATCC 26113 were tested. Maximum production of conidial protoplasts was obtained by preincubation of conidiospores on liquid minimal medium for 8 1/2 hrs. and by reaction with cell wall lytic enzyme for 3 hrs. Among effective cell wall lytic enzymes (Driselase, p-Glucuronidase, Novozyme and Zymolyase), Driselase was the most effective one on the production of conidial protoplasts. The production of conidial protoplasts was also enhanced by addition of 2-Deoxy-D-Glucose $(25{\mu}g/ml)$ into liquid minimal medium. Over 70% of the initial swollen conidia, preincubated in liquid minimal medium supplemented with 2-Deoxy-D-Glucose $(25{\mu}g/ml)$, were converted to protoplasts by incubation with 2% (w/v) commercial lytic enzyme Driselase at $28^{\circ}C$ for 3 hrs. The reversion frequency of the conidial protoplasts was about 30 times (25-50%) higher than that of mycelial protoplasts (0.6-1.3%).