• Korean Journal of Food Science and Technology
• /
• v.11 no.4
• /
• pp.249-257
• /
• 1979

Using the whole cell immobilized glucose isomerase which was prepared in the previous work (Korean J. Food Sci. & Technol., 11(3), 192 (1979), the specific activity of the immobilized enzyme was 48.1 units in the batch reaction system and 114 units in the continuous reaction system per g of matrix, respectively. In the continuous reactor the voidity was 0.36, which was suitable for the packed bed reactor. This immobilized enzyme showed a good operational stability of 115 days of half life which was sufficient for the continuous operation. The experimental result showed that 55 % of the substrate was converted to the product in the packed bed reactor. The productivity was dependent on the flow rate, column geometry, enzyme loading, and substrate concentration. An intrapaticle diffusion was observed by the effectiveness factor of 0.75 and interparticle diffusion by the decrease of Km' with increasing the superficial velocity.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1979.04a
• /
• pp.113.2-114
• /
• 1979

$\beta-Galactosidase$ is an enzyme which catalizes hydrolysis of lactose, a natural substrate, to glucose and galctose and transferring some monosac-charide units to active acceptors as sugar or alcohol. The occurence of $\beta-Galactosidase$ is known in various microorganisms, animals and higher plants and has been studied by many investigatigators. Especially, a great deal of articles for the enzyme of E. coli have been presented in genetic control mechanism and induction-repression effects of proteins, On the other hand, in the dairly products industry, it is important to hydrolyes lactosd which is the principal sugar of milk and milk products. During the last few years, the interest in enzymatic hydrolysis of milk lactose has teen increased, because of the lactose intolerence in large groups of the population. Microbial $\beta-Galactosidases$ are considered potentially most suitable for processing milk to hydrolyse lactose and, in recent years, the immobilized enzyme from yeast has been examined. Howev, most of the microbial $\beta-Gal$ actosidase are intracellular enzymes, except a few fungal $\beta-Gala-$ ctosidases, and extracellular $\beta-Galactosidase$ which may be favorable to industrial applieation is not so well investigated. On this studies, a mold producing a potent extracellular $\beta-Galactosidase$ was isolated from soil and identified as an imperfect fungus, Beauveria bassians. In this strain, both extracellular and intracellular $\beta-Galactosidases$ were produced simultaneously and a great increase of the extracellular production was acheved by improving the cultural conditions. The extracellular enzyme was purified more than 1, 000 times by procedures including Phosphocellulose and Sephadex G-200 chromatographies. Several characteristics of the enzymewas clarified with this preparation. The enzyme has a main subunit of molecular weight of 80, 000 which makes an active aggregate. And at neutral pH range, it has optimum pH for activity and stability. The Km value was determined to be 0.45$\times$10$^{-3}$ M for $o-Nitrophenyl-\beta-Galactoside.$ In any event, it is interesting to sttudy the $\beta-Galactosidase$ of B. bassiana for the mechanism of secretion and conformational structure of enzyme.

• Korean Journal of Microbiology
• /
• v.18 no.4
• /
• pp.161-171
• /
• 1980

A mutant strain having increased productivity of both enzymes, protease and amylase, was obtained from A. flavus KU 153, isolatd from South Korea for its high protease production by successive ultra-violet light irradiation, Two glucoamylases from the mutant strain selected were purified from wheat branculture by successive salting out, followed by dialysis and column chromatography, and their characteristics were compared with those of the wild strain. Glucoamylase production of the mutant selected was increased about 3.3 times compared with the wild strain, and 2.1 times compared with the parental strain, ${\alpha}-amylase$ activity of the mutant selected was about 2 times hugher than that of the wild strain or the parental strain. Protease and cellulase productivities of the muant selected were all alike compared with those of the highly proteolytic mutant, the parental strain. Therefore, it was considered that the back mutation on the protease production did not occurred in the formation process of the glucoamylase producing mutant. Total activities of glucoamylase I and II from the mutant selected were 2.86 and 3.65 times higher compared with those from the wild strain, respectively. Considering the optimal pH-thermal stability and Km-Vmax value of glucoamylase I and II from both strains, wild and mutant, it was deduced that the characteristics of glucoamylase I and II from the wild strain did not altered during the mutation process. Therefore, it was concluded that the selected mutant did not induce the formation of another glucoamylase isozyme, or the changes in the characteristics of the glucoamylase, but induce the productivity of the same glucoamylase I and II by the action of regulatory gene.

• Journal of Life Science
• /
• v.23 no.11
• /
• pp.1365-1370
• /
• 2013

Immobilized cellulase on weak ion exchange resin showed a typical Langmuir adsorption isotherm. Immobilized cellulase had better stability with respect to pH and temperature than free cellulase. Kinetics of thermal inactivation on free and immobilized cellulase followed first order rate, and immobilized cellulase had a longer half-life than free cellulase. The initial rate method was used to characterize the kinetic parameters of free and immobilized enzyme. The Michaelis-Menten constant $K_m$ was higher for the immobilized enzyme than it was for the free enzyme. The effect of the recirculation rate on cellulose degradation was studied in a recycling packed-bed reactor. In a continuous packed-bed reactor, the increasing flow rate of cellulose decreased the conversion efficiency of cellulose at different input lactose concentrations. Continuous operation for five days was conducted to investigate the stability of long term operation. The retained activity of the immobilized enzymes was 48% after seven days of operation.

• Journal of Life Science
• /
• v.12 no.1
• /
• pp.32-42
• /
• 2002

It was researched to react horse serum-BChE with hefanoylthiocholine chosen among choline esters. According as number of carbon of acyl group in choline esters was increased, reactivity was decreased but strength of ES complex was increased (Km=0,140mM). The pH-V/K profile for BChE-catalyzed hydrolysis of hexanoylthiocholine yields a p $K_{a}$ =4.974$\pm$0.028. This value is equal to recent literature that shows systematic shift from dependence of activity on the basic form fo a residue that huts a p $K_{a}$ =6.2~6.4 to catalysis by a residue or residues that has a p $K_{a}$ =4.7~5.0. The resulting kinetic solvent isotope effect of hexanoylthiocholine is $^{D/V}$K=1.18. The magnitude of the isotope effect suggests that proton transfer is not an element of transition-state stabilization.n.

• Journal of Preventive Medicine and Public Health
• /
• v.52 no.6
• /
• pp.427-432
• /
• 2019

Objectives: In Indonesia, 61 million adults smoked in 2018, and 59 million were exposed to secondhand smoke at offices or restaurants in 2011. The Presidential Decree 109/2012 encouraged local governments to implement a smoke-free policy (SFP), and the city of Jayapura enacted a local bill (1/2015) to that effect in 2015. This study aimed to evaluate compliance with this bill and to explore challenges in implementing it. Methods: We conducted a mixed-methods study. Quantitatively, we assessed compliance of facilities with 6 criteria (per the bill): the presence of signage, the lack of smoking activity, the lack of sale of tobacco, the lack of tobacco advertisements, the lack of cigarette smoke, and the lack of ashtrays. We surveyed 192 facilities, including health facilities, educational facilities, places of worship, government offices, and indoor and outdoor public facilities. Qualitatively, we explored challenges in implementation by interviewing 19 informants (government officers, students, and community members). Results: The rate of compliance with all 6 criteria was 17% overall, ranging from 0% at outdoor public facilities to 50% at health facilities. Spatial patterning was absent, as shown by similar compliance rates for SFP facilities within a 1-km boundary around the provincial and city health offices compared to those outside the boundary. Implementation challenges included (1) a limited budget for enforcement, (2) a lack of support from local non-governmental organizations and universities, (3) a lack of public awareness at the facilities themselves, and (4) a lack of examples set by local leaders. Conclusions: Overall compliance was low in Jayapura due to many challenges. This information provides lessons regarding tobacco control policy in underdeveloped areas far from the central government.

• Herbal Formula Science
• /
• v.29 no.4
• /
• pp.191-203
• /
• 2021

Objectives : In this study, we investigate the anti-allergic effects of Ullmus macrocarpa Hance (Ulmus) on RBL-2H3 mast cell (basophilic leukemia cell line), which are mediated by FcεRIs. Methods : We evaluated the effect of the ethanol extract of Ulmus on the allergic inflammatory response in IgE-antigen-mediated RBL-2H3 cells. Cell toxicity was determined by MTT assay and the markers of degranulation such as beta-hexosaminidase, histamine, PGD2, TNF-α, IL-4, IL-6 production of inflammatory mediators and FcεRI-mediated protein expression by western blot. Results : Ulmus inhibited degranulation and production of allergic mediators (e.g., TNF-α, IL-4, and IL-6) in them. Ulmus reduced histamine levels, expression of FcεRI signaling-related genes such as Lyn, Syk, and Fyn, and extracellular signal-regulated kinase phosphorylation in mast cells. Also, Ulmus reduced PGD2 release and cyclooxygenase-2 expression, and cytosolic phospholipase A2 phosphorylation in FcεRI-mediated RBL-2H3 mast cells. Conclusions : These results indicate that Ulmus exhibits anti-allergic activity through inhibition of degranulation and inflammatory mediators and cytokine release. These findings suggest that Ulmus may have potential as a prophylactic and therapeutic agent for the treatment of various allergic diseases.

• Herbal Formula Science
• /
• v.29 no.4
• /
• pp.181-189
• /
• 2021

Objectives : The calyx of Diospyros kaki Thunb. has usually been used to treat obstinate hiccup. This study investigated the protective effects of Diospyros kaki using C2C12 myoblasts of H₂O₂-induced oxidative stress. Methods : Cell viability and cytotoxicity were determined by MTT assay. The level of reactive oxygen species (ROS), malondialdehyde (MDA), and reduced glutathione (GSH) were measured by using optical properties. Results : The calyx of Diospyros kaki Thunb. extract showed no toxicity to C2C12 myoblasts until 20 ㎍/mL concentration and increased cell viability compared to the H₂O₂ treated group. The calyx of Diospyros kaki Thunb. extract inhibited the production of ROS and MDA at all concentrations. In addition, the calyx of Diospyros kaki Thunb. extract increased the concentration of GSH. Conclusion : This study provides that the calyx of Diospyros kaki Thunb. can be used as a potential material that exhibit antioxidative and protective effects on H₂O₂-induced oxidative stress in C2C12 Myoblasts.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.12
• /
• pp.1537-1546
• /
• 2022

Staphylococcus aureus is a cause of high mortality in humans and therefore it is necessary to prevent its transmission and reduce infections. Our goals in this research were to investigate the frequency of methicillin-resistant S. aureus (MRSA) in Taif, Saudi Arabia, and assess the relationship between the phenotypic antimicrobial sensitivity patterns and the genes responsible for resistance. In addition, we examined the antimicrobial efficiency and application of silver nanoparticles (AgNPs) against MRSA isolates. Seventy-two nasal swabs were taken from patients; MRSA was cultivated on Mannitol Salt Agar supplemented with methicillin, and 16S rRNA sequencing was conducted in addition to morphological and biochemical identification. Specific resistance genes such as ermAC, aacA-aphD, tetKM, vatABC and mecA were PCR-amplified and resistance plasmids were also investigated. The MRSA incidence was ~49 % among the 72 S. aureus isolates and all MRSA strains were resistant to oxacillin, penicillin, and cefoxitin. However, vancomycin, linezolid, teicoplanin, mupirocin, and rifampicin were effective against 100% of MRSA strains. About 61% of MRSA strains exhibited multidrug resistance and were resistant to 3-12 antimicrobial medications (MDR). Methicillin resistance gene mecA was presented in all MDR-MRSA strains. Most MDR-MRSA contained a plasmid of > 10 kb. To overcome bacterial resistance, AgNPs were applied and displayed high antimicrobial activity and synergistic effect with penicillin. Our findings may help establish programs to control bacterial spread in communities as AgNPs appeared to exert a synergistic effect with penicillin to control bacterial resistance.

• Korean Journal of Acupuncture
• /
• v.39 no.4
• /
• pp.184-190
• /
• 2022

Objectives : In our previous study, we developed the prototype of a lesson plan for meridian and acupuncture clinical skills education by applying the rapid prototyping to instructional systems design. The present study aimed to develop a teaching-learning manual, including the lesson plans, practice notes, and instructions for devices. We also aimed to present a guideline on how to use the manual in class. Methods : The manual and materials for teachers and learners were developed based on the solutions and the prototype derived from our previous study. Practical classes on meridian and acupuncture points consist of four major subjects, and the lesson plan and practice note were designed according to each topic. Results : Flipped learning, George's five-step method, peer role-play, and peer-led objective structured clinical examination (OSCE) were applied as main methodologies in the meridian and acupuncture points practical class. The teaching-learning manual, including practice notes, detailed lesson plan, OSCE checklist, and instruction manual for devices, was developed to be utilized at each stage of the learning activity. Conclusions : The application of the teaching-learning manual is expected to provide effective clinical skills education, strengthen learners' communication skills, establish professional identity, assess learners' performance, and provide immediate feedback. The educational effect of the manual for the existing class should be identified, and its feasibility should be verified by implementing it on another group. This manual could be helpful in designing classes for other subjects of Korean medicine, especially for clinical skills education.