• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.247-253
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• 1996

Changes in microorganisms, enzyme activities and major components of two types of Doenjang prepared with spring Meju and autumn Meju and Kochujang were investigated during 4 months of fermentation. The viable cell counts of aerobic bacteria in Doenjang and Kochujang were increased up to 60 days of fermentation, but viable cell counts of anaerobic bacteria did not show remarkable changes during fermentation. Viable cell count of yeast showed a rapid increase up to 15 days of fermentation in Doenjang and 60 days in Kochujang. It was found that $\alpha$-amylase activity of autumn Meju Doenjang and glucoamylase activity of Kochujang were higher than the other. Acidic and neutral protease showed the highest activity during 15-30 days of fermentation. The pH of Doenjang was increased up to pH 7.0 until 60 days of fermentation, but pH of Kochujang gradually decreased during fermentation. Moisture content of spring Meju Doenjang and Kochujang decreased to 40% during ferme- ntation and reducing sugar content of Kochujang increased up to 15 days of fermentation, but decreased after that.

• Journal of Environmental Science International
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• v.10 no.4
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• pp.259-267
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• 2001

Investigations were carried out to observe the seasonal succession of phytoplankton, and viable counts of bacteria from the mid to lower reaches of Nakdong Fiver. An intensive monitoring was conducted from May to December 1999 biweekly at 6 sites in a main channel and 3 tributaries. Although there are several sites with high nutrient loading from the basin, all of study sites showed mesotrophic states owing to high discharge(June~September). Relatively low algal biomass and CFUs(mean of chi. a, $12.3{\pm}$11.5 $\mu\textrm{g}${\el}l$, CFUs : 1.8${\times}10^7$) were observed during the rainy season. The diatom population was dominant(over 85% of total community) year-long with peaks(Stephanodiscus hantzchii) in the fall and winter. Dominance of blue-green algal groups during the summer was not observed in the summer. Microorganisms peaked in the summer and fall(June~September), affected mainly by the inputs of phytoplankton and nutrients. Biomass of phytoplankton and CFU counts were higher in the Kumho River than other tributaries and main channel.

• Food Science of Animal Resources
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• v.40 no.1
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• pp.118-131
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• 2020

It is necessary to add protective agents for protecting the probiotic viability in the preparation process of probiotics starter. In this study, we used whey protein concentrate (WPC), pullulan, trehalose, and sodium glutamate as the protective agent and optimized the proportion of protective agent and spray-drying parameters to achieve the best protective effect on Lactobacillus plantarum. Moreover, the viable counts of L. plantarum in starter stored at different temperatures (-20℃, 4℃, and 25℃) for 360 days were determined. According to response surface method (RSM), the optimal proportion of protective agent was 24.6 g/L WPC, 18.8 g/L pullulan, 16.7 g/L trehalose and 39.3 g/L sodium glutamate. The optimum spray-drying parameters were the ratio of bacteria to protective agents 3:1 (v: v), the feed flow rate 240 mL/h, and the inlet air temperature 115℃ through orthogonal test. Based on the above results, the viable counts of L. plantarum was 12.22±0.27 Log CFU/g and the survival rate arrived at 85.12%. The viable counts of L. plantarum stored at -20℃ was more than 10¹⁰ CFU/g after 200 days.

• Journal of Microbiology and Biotechnology
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• v.24 no.2
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• pp.225-235
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• 2014

Total 121 lactic acid bacteria were isolated from homemade Inner Mongolia extra hard Hurood cheese. Seven of these strains, identified as Lactobacillus plantarum, were studied for probiotic characteristics. All seven strains survived at pH 3.0 for 3 h, or in the presence of oxgall at 0.3% or 0.6% for 4 h, but their viabilities were affected to different extents at pH 2.0 for 3 h. Strains C37 and C51 showed better adherence to Caco-2 cells, and higher hydrophobicity. The seven L. plantarum strains were different in in vitro free radical scavenging activities and cholesterol-reducing ability. In vivo evaluation of the influence of L. plantarum C37 on the intestinal flora in a mouse model showed strain C37 could increase the viable counts of lactobacilli in feces of mice and decrease the viable counts of enterococci. When L. plantarum C37 was used to prepare probiotic Hurood cheese, it was able to maintain high viable counts (>7.8 log CFU/g) during the whole storage period, but the composition of the cheese was not changed. These results indicate that L. plantarum C37 could be considered as a promising probiotic strain.

• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.995-1004
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• 2017

Culture-dependent methods, such as heterotrophic plate counting (HPC), are usually applied to evaluate the bacteriological quality of hemodialysis water. However, these methods cannot detect the uncultured or viable but non-culturable (VBNC) bacteria, both of which may be quantitatively predominant throughout the hemodialysis water treatment system. Therefore, propidium monoazide (PMA)-qPCR associated with HPC was used together to profile the distribution of the total viable bacteria in such a system. Moreover, high-throughput sequencing of 16S rRNA gene amplicons was utilized to analyze the microbial community structure and diversity. The HPC results indicated that the total bacterial counts conformed to the standards, yet the bacteria amounts were abruptly enhanced after carbon filter treatment. Nevertheless, the bacterial counts detected by PMA-qPCR, with the highest levels of $2.14{\times}10^7copies/100ml$ in softener water, were much higher than the corresponding HPC results, which demonstrated the occurrence of numerous uncultured or VBNC bacteria among the entire system before reverse osmosis (RO). In addition, the microbial community structure was very different and the diversity was enhanced after the carbon filter. Although the diversity was minimized after RO treatment, pathogens such as Escherichia could still be detected in the RO effluent. In general, both the amounts of bacteria and the complexity of microbial community in the hemodialysis water treatment system revealed by molecular approaches were much higher than by traditional method. These results suggested the higher health risk potential for hemodialysis patients from the up-to-standard water. The treatment process could also be optimized, based on the results of this study.

• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.2049-2057
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• 2015

Various salt concentrations (1.0%, 1.3%, 1.6%, 1.9%, and 2.1% labeled as sample A, B, C, D, and E, respectively) were investigated for microbial diversity, identification of Lactic Acid Bacteria (LAB) in salted kimchi cabbage, prepared under laboratory conditions. These samples were stored at 4°C for 5 weeks in proper aluminum-metalized pouch packaging with calcium hydroxide gas absorber. A culture-independent method known as polymerase chain reaction - denaturing gradient gel electrophoresis was carried out to identify LAB distributions among various salt concentration samples that had identified 2 Weissella (W. confusa and W. soli), 1 Lactobacillus (Lb. sakei), and 3 Leuconostoc (Lc. mesenteroides, Lc. lactis, and Lc. gelidum) in the overall kimchi samples. The pH, titratable acidity, viable cell counts, and coliform counts were not affected by salt variations. In order to assess sensory acceptance, the conducted sensory evaluation using a 9-point hedonic scale had revealed that samples with 1.3% salt concentration (lower than the manufacturer's regular salt concentration) was more preferred, indicating that the use of 1.3% salt concentration was acceptable in normal kimchi fermentation for its quality and safety. Despite similarities in pH, titratable acidity, viable cell counts, coliform counts, and LAB distributions among the various salt concentrations of kimchi samples, the sample with 1.3% salt concentration was shown to be the most preferred, indicating that this salt concentration was suitable in kimchi production in order to reduce salt intake through kimchi consumptions.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.111-116
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• 2012

In this study, we investigated the microbial flora changes in Gugija-Liriope tuber Makgeolli during fermentation and storage periods. We brewed Gugija-Liriope tuber Makgeolli for a week through twostage fermentations and stored the fermentation broth for a month at $4^{\circ}C$ or $20^{\circ}C$. We collected the samples periodically and analyzed microbial flora changes using viable cell counts and PCR-denaturing gradient gel electrophoresis (DGGE). Yeast viable cells were seen to have decreased to 13% of pre-storage levels after storage for 15 days at $20^{\circ}C$; however significant changes were not observed during storage at $4^{\circ}C$. Prolongation of storage time dramatically decreased the availability of viable cells. Yeast viable cell numbers had decreased to 38% of pre-storage levels at $4^{\circ}C$ and 4.8% at $20^{\circ}C$ after storage for 30 days. The results of the DGGE profile for yeast showed that Saccharomyces cerevisiae and Saccharomyces sp. were the predominant strains at the beginning of fermentation and throughout the whole period of storage. Viable cell counts for total bacteria had decreased to 36% of pre-storage levels after storage for 15 days but did not significantly change for the full 30 days of storage at $4^{\circ}C$. Similarly, viable cell counts for bacteria had decreased to 5% while viable cell numbers did not significantly change for the full 30 days at $20^{\circ}C$. Viable cell counts for lactic acid bacteria were performed and the results were similar to those for total bacteria. The results of the DGGE profile for bacteria showed that Weissella cibaria was the predominant strain at the beginning of fermentation. However it had disappeared by the end of fermentation, and Lactobacillus fermentum and Pediococcus acidilactici became the predominant species during storage.

• KSBB Journal
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• v.18 no.1
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• pp.14-18
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• 2003

In this study of the simultaneous saccharification and fermentation (SSF) of paper sludge, fed-batch cultivation of Lactobacillus paracasei subsp. paracasei KLB58 was attempted to produce viable KLB58 cells and lactic acid. Optimal culture conditions, including the temperature and concentration of the supplemented enzyme, were examined in terms of lactic acid production and viable cell count. When the effects of culture temperature and $\beta$-glucosidase concentration were examined in fed-batch SSF, the highest viable cell counts and lactic acid production (i.e. 5$\times$$10^9$ CFU/ml and 45 g/L, respectively) were obtained at 37$^{\circ}C$ and 2 unit/ml of $\beta$-glucosidase.

• Korean journal of food and cookery science
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• v.20 no.4
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• pp.418-422
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• 2004

We investigated microbial populations of an upland and cultivated Codonopsis lanceolata. The microbial populations from both types of soils were also investigated. There were more than 10 microorganisms existed in upland than cultivated one. The total viable cell counts of C. lanceolata from upland and cultivated one, especially in the upper zone, were 9.7x10$\^$6/ CFU/g and 4.2${\times}$10$\^$6/ CFU/g, respectively. As a results, upper parts of C. lanceolata in upland were considered to harbour approximately more than 2.3 fold higher microorganisms than in cultivated one. However, the total viable cell counts between the two soil habitat, that is, 1.2${\times}$10$\^$7/ CFU/g from upland and 1.0x10$\^$7/ CFU/g from cultivated, were not significantly different. We also examined the unique flavor producing microorganisms in the soil extract broth including 25% C. lanceolata extract. One microorganism was detected in upper pars of C. lanceolata and upland soil. No. 6, microorganism causing the characteristic flavor of C. lanceolata was continued as Actinomyces by microscopy.

• Korean journal of food and cookery science
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• v.23 no.2 s.98
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• pp.252-260
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• 2007

This study was performed to provide basic data for the operation of the sous vide cook-chill system(SVCC) by comparing and evaluating the quality of SVCC prepared foods to those prepared using the cook-chill system(CC). Foremost, the microbial risk was less and the food quality excellent when SVCC was used compared to CC, where changes in pH, Aw and moisture loss were less with SVCC. The CC and SVCC Aw value were 0.93 and 0.92 and 0.92 and 0.95 at 0 days and 15 days, respectively. Secondly, the microbial quality by storage days was relatively high with SVCC. The CC and SVCC viable cell and coliform counts were 4.43 and 4.37 LogCFU/g, and 4.53 and 3.60 LogCFU/g, respectively, by 15 days. Also, after reheating, the viable cell and coliform counts satisfide the standards applied in processed food(5.0 and 2.0 LogCFU/g respectively). Lastly, the sensory scores for SVCC were higher than those for CC. Thus, microbial and sensory qualities by days of storage were acceptable and overall quality satisfaction was better for SVCC than CC.