• Food Science and Biotechnology
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• v.15 no.5
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• pp.792-798
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• 2006

The probiotic characteristics of a total of 137 lactic acid bacterial strains isolated from soybean paste were investigated. Among those tested, the D37 strain was selected as a probiotic bacteria due to its acid and bile tolerance, and its strong anti-cancer and antibacterial activities. The D37 strain showed highly stable viability at acidic pH for 2 hr, and was very stable in 10% bovine bile. The viability of human colon cancer HT-29 cells was inhibited more than 60% at a $200\;{\mu}/mL$ concentration of D37 cell-free culture supernatant, and the degree of inhibition was concentration-dependent. The D37 strain showed a wide range of antibacterial activities against food-borne pathogenic bacteria such as Escherichia coli O157, Listeria spp., Vibrio spp., Salmonella spp., and Staphylococcus aureus. According to phenotypic characteristics and the utilization of various sugars, the D37 strain was identified as Lactobacillus cellobiosus.

• Journal of Sericultural and Entomological Science
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• v.37 no.1
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• pp.27-32
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• 1995

Studies were carried out to report breeding procedure and characteristics of Fb, a strain of silkworm with abnormal food habit polyphagous. Selection was continued up to the 14th generation toward higher incidence of cabbage leaves feeding variants. In the autumn of 1992(7th generation), selected strain were subjected to severe selection by feeding them on artificial diet that did not contain mulberry leaf powder. The results were clearly positive and reached to higher than 95% of cabbage feeding in the 14th generation. This strain was first discovered by feeding cabbage leaves, but later they were observed to eat some kind of plants like lettuce, Chinese cabbage, radish, beet, apple, persimmon, pear, etc. As described above the procedure, cabbage feeding trait was clearly heritable. The strain responsible for this traits was named Fb.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.53-58
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• 1996

The characterstics of the soy protein curd(eczyme-, HCI- and Ca-surd) were shown by scanning electron micrographs and gel electrophoreis. The emulsion stability of enzyme-curd showed high value in the range of pH 2~10and wide range of temperature(20~8$0^{\circ}C$). While at the isoelectric point(pH5.0), the emulsion stability of the HCI-and Ca-curd was decreased remarkably, and the emulsion stability of temperature was reduced quickly to the 60% and 40% at the 4$0^{\circ}C$. The foam stability of enzyme-curd was slightly higher than that HCI-and CA-curd in all ranges of pH and temperature. The feature of SEM of enzyme-cured produced degradation products faster than that of the HCI- and Ca-curd.

• Food Science of Animal Resources
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• v.42 no.6
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• pp.1009-1019
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• 2022

In recent years, biocontrol of foodborne pathogens has become a concern in the food industry, owing to safety issues. Listeria monocytogenes is one of the foodborne pathogens that causes listeriosis. The major concern in the control of L. monocytogenes is its viability as it can survive in a wide range of environments. The purpose of this study was to isolate lactic acid bacteria with antimicrobial activity, evaluate their applicability as a cheese starter, and evaluate their inhibitory effects on L. monocytogenes. Lactococcus lactis strain with antibacterial activity was isolated from raw milk. The isolated strain was a low acidifier, making it a suitable candidate as an adjunct starter culture. The commercial starter culture TCC-3 was used as a primary starter in this study. Fresh cheese was produced using TCC-3 and L. lactis CAU2013 at a laboratory scale. Growth of L. monocytogenes (5 Log CFU/g) in the cheese inoculated with it was monitored during the storage at 4℃ and 10℃ for 5 days. The count of L. monocytogenes was 1 Log unit lower in the cheese produced using the lactic acid bacteria strain compared to that in the cheese produced using the commercial starter. The use of bacteriocin-producing lactic acid bacteria as a starter culture efficiently inhibited the growth of L. monocytogenes. Therefore, L. lactis can be used as a protective adjunct starter culture for cheese production and can improve the safety of the product leading to an increase in its shelf-life.

• Journal of Sericultural and Entomological Science
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• v.38 no.2
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• pp.113-117
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• 1996

To analyze the mode of inheritance of this gene in Fb strain, carried out cross experiment between Fb and several Japanese and Chinese origin strains. The results of crossing experiments, feeding ratio in F1 hybrids were nearly the mid of parents, F2 and backcrossed hybrids(BF1) were approximately intermediate between Fb and other strains. Hence, the feeding habit of cabbage leaves on Fb strain is assume to be incomplete dominance.

• Microbiology and Biotechnology Letters
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• v.51 no.4
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• pp.555-558
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• 2023

Staphylococcus aureus is a prominent multidrug-resistant pathogen known for its resistance to a variety of antibiotics. To combat this, a wide range of antibiotics, including quinolones, is utilized. While the efficacy of quinolones against S. aureus has been established, the rise in quinolone-resistant strains, particularly in methicillin-resistant S. aureus (MRSA), has necessitated a shift in their usage patterns. Genomic sequencing plays a crucial role as it offers insights into the genetic mechanisms of resistance. Thus, we report the complete genome sequence of an oxolinic acid-resistant strain of S. aureus isolated from sweet potato leaves, a crop commonly cultivated in Korea.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.419-429
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• 2023

Ultraviolet C (UV-C, 200-280 nm) light has germicidal properties that inactivate a wide range of pathogenic and spoilage microorganisms. UV-C has been extensively studied as an alternative to thermal decontamination of fruit juices. Recent studies suggest that the efficacy of UV-C irradiation in reducing microorganisms in fruit juices is greatly dependent on the characteristics of the target microorganisms, juice matrices, and parameters of the UV-C treatment procedure, such as equipment and processing. Based on evidence from recent studies, this review describes how the characteristics of target microorganisms (e.g., type of microorganism/strain, acid adaptation, physiological states, single/composite inoculum, spore, etc.) and fruit juice matrices (e.g., UV absorbance, UV transmittance, turbidity, soluble solid content, pH, color, etc.) affect the efficacy of UV-C. We also discuss the influences on UV-C treatment efficacy of parameters, including UV-C light source, reactor conditions (e.g., continuous/batch, size, thickness, volume, diameter, outer case, configuration/arrangement), pumping/flow system conditions (e.g., sample flow rate and pattern, sample residence time, number of cycles), homogenization conditions (e.g., continuous flow/recirculation, stirring, mixing), and cleaning capability of the reactor. The collective facts indicate the immense potential of UV-C irradiation in the fruit juice industry. Existing drawbacks need to be addressed in future studies before the technique is applicable at the industrial scale.

• Preventive Nutrition and Food Science
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• v.2 no.2
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• pp.109-120
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• 1997

In order to elucidate roles of lactic acid bacteria(LAB) for the antibiosis occurring in th fermenting environment of Kimchi, 2.052 strains of LAB were isolated from Kimchi. Fifty tow strains which showed antagonistic effect against 4 indicator strains were finally selected and investigated. Based upon responses to protease treatment, antibiosis of the 52 strains of LAB were classified into 3 types. Type A antibiosis resulted from action of antibiotic-like substances which were not affected by protease treatment and which had broad action spectra against even natural inhabitants of Kimchi. Type B antibiosis was due to bacteriocin-like substances which were very sensitive to treatment of protease and more effective against foreign bacteria than original inhabitant microflora. Type C antibiosis was owing to proteinaceous compounds which were activated or induced by the presence of protease and then exerted antibacterial activities. Therefore, lactic acid bacteria appeared to contribute to antibiosis of Kimchi by the concerted action of these three different types of antibacterial compounds. As one of model system for type B bacteriocin, the antagonistic compound produced by LAB31-9 as well as th producer strain itself was further charaacterized. Strain LAB31-9 was identified as L. casei. Bacteriocin produced by LAB31-9 was proteinaceous and stable over wide range of pH and to various solvents, but very labile to heat treatment. Its mode of action was bactericidal. Based upon these data, bacteriocin produced by LAB31-9 was named as 'caseicin K319'. Genetic determinant for the bacteriocin production of LAB31-9 was located in the chromosome.

• Korean Journal of Food Science and Technology
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• v.49 no.1
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• pp.28-34
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• 2017

Biocatalytic modification of natural resources can be used to generate novel compounds with specific properties, such as higher viscosity and reactivity. The production of hydroxy fatty acids (HFAs), originally found in low quantities in plants, is a good example of the biocatalytic modification of natural vegetable oils. HFAs show high potential for application in a wide range of industrial products, including resins, waxes, nylons, plastics, lubricants, cosmetics, and additives in coatings and paintings. In a recent study, Pseudomonas aeruginosa strain PR3 was used to produce 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) from oleic acid. This present study focused primarily on the utilization of three natural nut oils obtained from the Philippines -pili nut oil (PNO), palm oil (PO), and virgin coconut oil (VCO)- to produce DOD by P. aeruginosa strain PR3. Strain PR3 produced DOD from PNO and PO only, with PNO being the more efficient substrate. An optimization study to achieve the maximum DOD yield from PNO revealed the optimal incubation time and medium pH to be 48 h and 8.0, respectively. Among the carbon sources tested, fructose was the most efficiently used, with a maximum DOD production of 130 mg/50 mL culture. Urea was the optimal nitrogen source, with a maximum product yield of 165 mg/50 mL culture. The results from this study demonstrated that PNO could be used as an efficient substrate for DOD production by microbial bioconversion.

• Korean Journal of Food Science and Technology
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• v.9 no.4
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• pp.277-283
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• 1977

1) Higher yield of red color was observed by the isolated strain (Monascus D-7) than the type cultures in steamed rice medium. 2) In a case of Monascus purbigerus IAM 8004, best yield of color was obtained at Lin's submerged culture medium containing 1% wheat bran, 2% starch and 3% corn meal instead of rice powder as carbon source. However, in a case of isolated strain (M. D-7), good result was shown at 1% rice bran and 2% starch as a source of carbon in Lin's medium. 3) Good yields were obtained from both strains in Nishikawa's medium which was added with 3% defatted soybean flour. 4) There were no significant differences in pigment extractability among solvents. Extracted pigment was stable in wide range of pH and heat, whereas relatively unstable in sunlight. 5) Toxicological study of extracted pigment determined $LD_{50}$ at 0.2539g/20g, when injected in mouse. When injected in to mouse in 25% ethanol solution: considering the toxicity of ethanol, the toxicity of pigment itself is believed to be none.