• Microbiology and Biotechnology Letters
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• v.21 no.3
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• pp.200-206
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• 1993

The effect of pH (7, 5 and 4) and nisin (100 and 200IU/ml) on heat resistance of Listeria monocytogenes Scott A were determined using citrate-phosphate buffer system. Heat resistance of vegetative and starved cell was decreased as pH value was lower at 65 and 72C. Starved L. monocytogenes was more resistant than vegetative cell at both temperature. Heat resistance of vegetative and starved cell was decreased significantly with treatment of nisin. The effect of nisin was increased significantly at low pH(5, 4). Adherent microcolony was more resistant to heat and nisin than planktonic cell. Contamination of L. monocytogenes may be prevent by using nisin in food and food processing environments.

• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.504-509
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• 1989

Fermentation condition of Streptococcus lactis IFO 12007 for nisin production was examined. The optimal glucose concentration was 60g/ι. The pH and temperature optimum were 6.5 and 31$^{\circ}C$, respectively. The maximum nisin activity in batch culture was 2000IU/$m\ell$. The fermentation quotients after 7 hours of fermentation in batch culture were; specific glucose uptake rate:0.59g/g/h , specific nisin productivity: 34924IU/g/h, product yield: 5944IU/g, growth yield:0.24, biomass:4.81g/ι. The specific growth rate was affected by pH and temperature and the activation energy for growth was 1.35kcal/mole. pH control was essential for nisin production. Fed-batch culture using 20g/$\ell$ glucose medium produced 1420IU/$m\ell$ after 14 hours. The continuous culture could be operated at below 0.38h$^{-1}$ for nisin production. The steady state nisin concentration and specific nisin productivity were 740IU/$m\ell$ and 45000IU/g/h. The growth yield and maintenance energy were 0.144 and 207mg glucose/g-cell/h.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.225-228
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• 2005

The aim of this study is to evaluate the microbial safety and physical qualities of Korean jerky, and the effect of nisin during storage. Jerky processed packages with or without nisin (100 IU or 500 IU) were stored at room temperature (25 $^{\circ}C$) for 60 days, and samples measured for quality at regular intervals throughout this storage period. In the case of 25$^{\circ}C$ storage, the number of mesophilic microorganisms in seasonedbeef packages without nisin increased markedly, but with nisin there was no observed increase. B. cereus cells showed similar trends, although coliform was not detected in all samples. At 25$^{\circ}C$ storage, changes in the cutting force of packages containing nisin showed no significant change, packages without nisin decreased markedly.

• Food Science and Biotechnology
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• v.14 no.3
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• pp.358-362
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• 2005

Eudragit E100 microcapsules containing nisin were prepared and employed to control the ripening of kimchi. The recovery yields of microcapsules without/with nisin ranged from 93.53 to 94.61 % and 92.85 to 94.09 %, respectively. The particle size of microcapsules decreased (>200 to $100\;{\mu}m$) as the amount of aluminium tristearate increased from 6.0 to 15 %. The microcapsules were morphologically spherical and possessed rough surface. Nisin was completely released from the microcapsules within a day at pH 3.0 and within two days at pH 4.0, 5.0, and 6.0, respectively, whereas half the amount of nisin was released at pH 7.0 within two days. During fermentation of kimchi with microcapsules containing nisin, the pH decrease was retarded which resulted in a constant pH of approximately 4.2. The pH of 4.2 was optimal for ripening of kimchi for a longer period of time when compared with samples without nisin.

• Journal of Microbiology and Biotechnology
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• v.4 no.2
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• pp.141-145
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• 1994

Conventional commercial thermal process for preparing Sikhae (Rice beverage) in a hermetically sealed container was evaluated to solve the nutritional deterioration and organoleptic inferiority problem caused by severe heat treatment. A milder thermal process with an aid of Nisin, a GRAS-grade, selectively germicidal compound, was introduced to destroy the putrefactive microorganisms. In this experiment, hot-filling method with Nisin, and thermal processing (at 110$^{\circ}C$ for 15 minutes with Nisin, at 121$^{\circ}C$ for 25 minutes without Nisin) were compared. The quality of Sikhae could be enhanced and over 90% of the thermal process could be conserved by this process in terms of sterilizing value without quality deterioration when processing the bottled Sikhae at 110$^{\circ}$ for 15 minutes $\{(F^{10}{_{121})_{process}=1.54\}$.

• Food Science of Animal Resources
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• v.43 no.5
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• pp.751-766
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• 2023

Helicobacter pylori is a bacterium that naturally thrives in acidic environments and has the potential to induce various gastrointestinal disorders in humans. The antibiotic therapy utilized for treating H. pylori can lead to undesired side effects, such as dysbiosis in the gut microbiota. The objective of our study was to explore the potential antibacterial effects of nisin and lactic acid (LA) in yogurt against H. pylori. Additionally, we investigated the anti-inflammatory effects of nisin and LA in human gastric (AGS) cells infected with H. pylori. Nisin and LA combination showed the strongest inhibitory activity, with confirmed synergy at 0.375 fractional inhibitory concentration index. Also, post-fermented yogurt with incorporation of nisin exhibited antibacterial effect against H. pylori. The combination of nisin and LA resulted in a significant reduction of mRNA levels of bacterial toxins of H. pylori and pro-inflammatory cytokines in AGS cells infected with H. pylori. Furthermore, this also increased bacterial membrane damage, which led to DNA and protein leakage in H. pylori. Overall, the combination of nisin and LA shows promise as an alternative therapy for H. pylori infection. Additionally, the incorporation of nisin into foods containing LA presents a potential application. Further studies, including animal research, are needed to validate these findings and explore clinical applications.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.414-417
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• 1992

In order to study the addition effect of Leuconostoc mesenteroides and nisin on Escherichia coli and lactic acid bacteria during fermentation and storage of Kimchi, Kimchi was stored at 4$^{\circ}C$ for 7 days and then in-creased the temperature to $25^{\circ}C$. Lactic acid content on Kimchi fermentation at 4$^{\circ}C$ was maintained initial content which was increased upto 0.9% and lactic bacteria was also increased after switching to $25^{\circ}C$. E. coli, on the other hand, was a little decreased from the initial level, but a significant decrease was found for the those Kimchi of Leuconostoc muenteroides added and nisin treated group when the fermentation temperature was switched to $25^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1152-1157
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• 2005

The effect of carbon sources on nisin Z biosynthesis in Lactococcus lactis subsp. lactis A164 was studied in batch culture using M17 broth containing different carbon sources. Among the eleven carbon sources tested, glucose, sucrose, and lactose were suitable carbon sources for cell growth of L. lactis A164. In particular, cells grown on lactose produced at least 3-fold greater amount of nisin Z than those on other carbon sources. Galactose resulted in less amount of cell mass than did sucrose or glucose, but gave a higher level of nisin Z activity. Northern blot analysis revealed. that lactose increased the transcription of the nisZ pre-peptide gene. Although galactose was less efficient than lactose, it increased the transcription of nisZ along with a higher level of nisin Z than did sucrose and glucose. These results suggest that the increased nisin Z production is correlated with the induction of nisZ by lactose and galactose. Among all the carbon sources tested, no remarkable differences were observed in nisRK and nisFEG transcripts, indicating that the lactose- or galactose-mediated induction is unique to the nisZ promoter.

• Journal of Food Hygiene and Safety
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• v.36 no.6
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• pp.488-492
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• 2021

One of the well characterized bacteriocins, nisin, shows strong antimicrobial activity against pathogenic bacteria such as Listeria monocytogenes and Staphylococcus aureus. This study evaluated the synergistic effect of commercial nisin and SAP84 bacteriophage on S. aureus. Nisin showed antimicrobial activity against S. aureus KCTC 3881 in a dose-dependent manner. Eighteen IU/mL of the nisin decreased 4.03 Log CFU/mL of the strain in MRS broth after six hours compared with the controlled subject. On the other hand, the same dose of the nisin decreased 5.54 Log CFU/mL when co-treated with 0.1 MOI of the bacteriophage SAP84. Furthermore, the combination of nisin and SAP84 was successfully applied for controlling the S. aureus strain in lettuce.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.16 no.1
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• pp.5-7
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• 2010

Two kinds of polymer coating (acrylic polymer and vinyl acetate ethylene copolymer) added with 5% nisin were fabricated on the paperboards and tested in their antimicrobial activity against Micrococcus flavus ATCC 10240 inoculated into water contacting the coating at $10^{\circ}C$. Vinyl acetate ethylene copolymer giving faster and higher nisin migration presented the greater reduction in the microbial count than the other coating, which endorsed that the migrated nisin is mainly responsible for the microbial inhibition or destruction. There was also a slight effect of the coating polymer itself in the microbial inhibition.