• Journal of Microbiology and Biotechnology
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• v.26 no.4
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• pp.666-674
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• 2016

The bacterial strains were screened as potential starters for fermenting low-salt doenjang (a Korean traditional fermented soybean paste) using Korean doenjang based on proteolytic and antipathogenic activities under 6.5-7.5% NaCl conditions. Phylogenetic analysis based on 16S rRNA gene sequences showed that they all belonged to the genus Bacillus. Proteolytic and antipathogenic activities against Escherichia coli, Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, and Aspergillus flavus, as well as fibrinolytic, amylase, and cellulase activities of the 10 strains were quantitatively evaluated. Of these, strains D2-2, JJ-D34, and D12-5 were selected, based on their activities. The functional, phenotypic, and safety-related characteristics of these three strains were additionally investigated and strains D2-2 and D12-5, which lacked antibiotic resistance, were finally selected. Strains D2-2 and D12-5 produced poly-γ-glutamic acid and showed various enzyme activities, including α-glucosidase and β-glucosidase. Growth properties of strains D2-2 and D12-5 included wide temperature and pH ranges, growth in up to 16% NaCl, and weak anaerobic growth, suggesting that they facilitate low-salt doenjang fermentation. Strains D2-2 and D12-5 were not hemolytic, carried no toxin genes, and did not produce biogenic amines. These results suggest that strains D2-2 and D12-5 can serve as appropriate starter cultures for fermenting low-salt doenjang with high quality and safety.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.391-402
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• 2017

Lactic acid bacteria (LAB) are widely used as starter culture in food fermentation due to their harmless entity and health beneficial properties along with the ability to change texture, aroma, flavor and acidity of food products. In this study, five different LAB (FB003, FB058, FB077, FB081, and FB111) isolated from different Korean traditional fermented foods, assigned to Lactobacillus plantarum, Pediococcus pentosaceus, Weissella viridescens, Lactobacillus sakei, and Leuconostoc mesenteroides, respectively, on the basis of their physiological properties and 16S rRNA sequence analysis, to use as fermentation starter and check their ability to fasten the ripening time as well as the overall optimization in the fermentation condition. To check their suitability as starters, their safety, acid and bile tolerance, NaCl and temperature resistance, susceptibility to common antibiotics, and antimicrobial activities were determined. Squid jeotgal samples were prepared by adding $10^8CFU/g$ of each strain in different samples, which were then kept for fermentation at $4^{\circ}C$ and checked for their antioxidant activities at 0, 7, 15, and 21-day intervals. The samples fermented with FB003 and FB077 displayed the highest antioxidant activity. This study revealed two effective starter cultures (FB003, FB077) for squid jeotgal fermentation, which presented increased functionalities. The results of this study will lead to the development of novel industrial-scale production avenues for jeotgal preparation, and offer new insights into the prevention and control of chronic diseases.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1100-1108
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• 2009

Lactic acid bacteria (LAB) isolated from various fruits and vegetables were screened in order to determine appropriate fermentation starters for manufacturing functional fermented onion juice. From the initial screening test comprising more than 700 isolated LAB, 16 isolates were selected based on their acid production rate. Among the selected isolates, the fermentation broth of KC-007 exhibited the highest electron donating and nitrite scavenging activities, with values at pH 1.2 of 95.6 and 68.7%, respectively. From the overall results obtained in this study, we finally selected the bacterium KC-007 as a fermentation starter. This bacterium was identified and named as Pediococcus pentosaceus based on its morphological and physiological characteristics, carbon-utilization pattern (as assessed using an API 50CHL kit), and molecular genetic characteristics (as assessed using the nucleotide sequence of the 16S rRNA gene). The optimal temperature, pH, and starter inoculation concentration (v/v) required for growth of the isolated strain were $40^{\circ}C$, pH 4.0-6.0, and 2%(v/v), respectively.

• Journal of Microbiology and Biotechnology
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• v.29 no.4
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• pp.527-537
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• 2019

Three types of meongge (Halocynthia roretzi) jeotgal (MJ) were prepared with 3 different types of salts (12%, w/v): purified salt (PS), solar salt aged for 3 years (SS), and bamboo salt that had been recrystalized 3 times (BS). One set of MJ was fermented with starters, Bacillus subtilis JS2 and Tetragenococcus halophilus BS1-37 (each 6 log CFU/g), and another set without starters for 42 days at $10^{\circ}C$. The LAB count of the SSMJ (non-starter) was highest at day 28 (2.30 log CFU/g). The pH of the PSMJ and SSMJ was 5.72-5.77 at day 0, and 5.40-5.50 at day 42. BSMJ showed higher pH and lower titratable acidities than other samples. Amino-type nitrogen (ANN) increased continuously, and SSMJ showed higher values than other samples from day 14. Bacterial species of non-starter MJ were examined by culture independent method. Clone libraries of 16S rRNA genes were constructed in Escherichia coli from total DNA from non-starter MJ samples at day 0, 14, and 28. Thirty clones per each sample were randomly selected and DNA sequences were analyzed. Variovorax sp., uncultured bacterium, and Acidovorax sp. were the most dominant group at day 0, 14, and 28, respectively. Lactobacillus sakei and Streptococcus sp. were the next dominant group in SSMJ at day 28. A Streptococcus sp. was detected from PSMJ at day 28. Sensory evaluation for MJ samples at day 28 showed that SSMJ got higher overall acceptability scores. These results showed that solar salt can cause desirable changes in the microbial community of fermented foods, thereby positively affecting their overall quality.

• Animal Bioscience
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• v.35 no.12
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• pp.1881-1891
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• 2022

Objective: The present study aimed to quantify the effects of fermented soybean meal (FSBM) on broiler chickens' performance by employing a meta-analysis approach. Methods: A total of 16 studies were included in the database after being systematically selected using a PRISMA protocol. Hedges' g effect size was used to quantify pooled standardized mean difference (SMD) using random-effects models at 95% confidence intervals (95% CI). Publication bias among studies was computed with Egger's test and visualized using funnel plots. Results: Results indicated that dietary FSBM inclusion increased final body weight (BW) (SMD = 0.586, 95% CI: 0.221 to 0.951, p = 0.002) of broiler chickens, particularly in starter period (SMD = 0.691, 95% CL: 0.149 to 1.233, p = 0.013) while in the finisher period, the effect was weaker (SMD = 0.509, 95% CI: 0.015 to 1.004, p = 0.043). Average daily gain (ADG), feed intake (FI), and feed conversion ratio (FCR) were not affected with FSBM inclusion when compared to control. Subgroup analysis revealed that FI increased in starter period (SMD = 0.582, 95% CI: 0.037 to 1.128, p = 0.036). When considering types of microorganism as moderating variables in the subgroup analysis, we found that Aspergillus oryzae, mixed probiotics+bromelain protease, Bacillus subtilis, and Lactobacillus bacteria significantly increased ADG and FI (p<0.01). Additionally, either Bacillus subtilis+protease or Bacillus subtilis alone decreased FCR (p<0.001). However, meta-regression analysis showed that levels of FSBM inclusion had no effects on final BW (p = 0.502), ADG (p = 0.588), FI (p = 0.861), and FCR (p = 0.462). Conclusion: Substituting SBM in broiler chickens' diet with FSBM improved BW of broiler chickens, especially in the starter period whereas the effects on ADG, FI, and FCR were mostly dependent on microbial strains used for fermentation.

• Microbiology and Biotechnology Letters
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• v.42 no.1
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• pp.1-10
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• 2014

Most microorganisms have been used for foods for such a long period of time with no question posed for their safety. However, the progress of food processing technology has activated international food trades, and the consumers and authorities of import countries have come to question the safety of microorganisms used in foods. At present, the most widely known safety standards are Generally Recognized as Safe (GRAS) status from the US Food and Drug Administration (FDA) and Qualified Presumption of Safety (QPS) status by the European Food Safety Authority (EFSA). GRAS status is not for the safety of microorganisms themselves but for the permissibility of strains or cultures in specific food uses. QPS provides a qualified generic approval to a defined taxonomic unit. The increase of commercialized traditional fermented foods in Korea has spurred the starter development for traditional food fermentations. However, starter development in Korea has been carried out based on the technological properties of microorganisms with no research on developing a standardized tool for safety assessment. In the globalization of traditional Korean fermented foods, technological properties as well as safety of future starters should be guaranteed, and establishment of the safety assessment regulation for microorganisms used for foods is necessary.

• Journal of Life Science
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• v.13 no.1
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• pp.59-66
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• 2003

The bacterial strain was isolated from the 4th day's fermented Dolsan Leaf Mustard Kimchi(DLMK) at $20^{\circ}C$/TEX>. It was used as Kimchi starter, and then its physiological activity was investigated for 50 days at $4^{\circ}C$/TEX> and $10^{\circ}C$/TEX> The physiological activity of DLMK was examined for both antioxidative and Angiotensine Converting Enzyme(ACE) inhibitory activity. In the starter-inoculated DLMK(1 X $10^{10}$ CFU/mL) at 4 and $10^{\circ}C$, the optimal ripening period was more shortend than that of control(without starter) up to about 5.6 and 5 times, respectively. The maximal antioxidative activity in the starter-inoculated DLMK(1 X $10^{10}$ 10 CFU/mL) at 4 and $10^{\circ}C$ were 67% and 75%, respectively. The yield of cell concentration per day($lnX_{max}$/$t_{max}$) and the yield of antioxidative activity per day($P_{max}$/ｔ$t_{max}$) had a linear relationship. Also, the yield of antioxidative activity per day was increased with increasing the concentration of inoculated bacterium. By adding 1 X $10^{10}$ CFU/mL at 4 and $10^{\circ}C$, the ACE inhibitory activity of DLMK was maximal. The rates of inhibiting activities were 52% and 76%, respectively. Consequently, physiological activities were significantly affected by the inoculation concentrations of starter, but bacterium itself was not appeared the physiological activity. We assume that the bacterium metabolizes certain materials in DLMK and released compounds such as glucosinolates or its metabolized forms from DLMK show the antioxidative and ACE inhibitory activity.

• Journal of Dairy Science and Biotechnology
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• v.36 no.3
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• pp.178-185
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• 2018

Kefir, which originates in the Caucasian mountains, is a cultured milk beverage produced by a combination of acidic and alcoholic fermentation. Kefir products are commonly used as food vehicles to deliver health-promoting materials including kefran and lactic acid bacteria to consumers. The aim of this study was to develop a freeze-dried starter culture without yeast and assess the suitability of kefir-like dairy products for the growth of lactic acid bacteria and the acidification of milk. Pasteurized whole milk (SNF 8.5%) stored at $25^{\circ}C$ was aseptically inoculated with starter cultures (0.002% w/v); it was kept at $25^{\circ}C$ until the pH attained a value of 4.6. Ten grams of the kefir-like product sample was diluted with 90 mL of 0.15% peptone water diluent in a milk dilution bottle, followed by uniform mixing for 1 min. Viable cells of Lactobacillus species were enumerated on modified-MRS agar (pH 5.2), with incubation at $37^{\circ}C$ for 48 h. Viable cells of Lactococcus species were enumerated on M17-lactose agar, with incubation at $32^{\circ}C$ for 48 h. The pH attained a value of 4.6 after fermentation for 9 h 30 min (Starter 1), 9 h 45 min (Starter 2), and 12 h (Starter 3). The viable cell count of Lactobacillus sp. and Lactococcus sp. was initially $10^5{\sim}10^6CFU/g$; it increased significantly to $10^9CFU/g$ after 12 h of incubation. During the storage of the kefir-like products at $4^{\circ}C$ for 1 4 days, the total viable cell numbers were unchanged, but the pH decreased slightly. The consistency of the kefir products increased gradually during the storage. The organoleptic properties of the kefir products fermented using the new starter culture are more desirable than those of commercial kefir. These results suggest that the newly developed starter culture without yeast could be suitable for kefir fermentation.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.70-79
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• 2014

This study was conducted to develop natural additive for the improvement of lipid stability and the suppression of pathogenic contamination during the storage periods of fermented sausage. Fermented sausage prepared with grapefruit extract showed good suppression of lipid oxidation and pathogenic bacterial growth, and it was higher than that of fermented sausage prepared with nitrate until 7 days of storage. Fermented sausage prepared with treatment A (sodium nitrate and L. acidophilus), B (sodium nitrate and L. brevis), C (ascorbic acid and L. brevis) and D (grapefruit extract and L. brevis) were compared. As results, treatment C and D showed the lowest pH changes among treatments, and the highest growth of lactic acid bacteria was represented in treatment D. In the suppression effect of E. coli, the bacterial count was below 100 in all treatment except the treatment A. There were no differences among treatment in the brightness of meat color (p<0.05). Treatment D showed significantly high values in the redness, but showed the lowest values in the yellowness. In sensory and texture test, treatment C and D were superior compared to others. Therefore, grapefruit was represented as a good source of antioxidant for fermented sausage, and L. brevis isolated from kimchi was effect in lowering pH value of sausage during fermentation and it was also effective to persist fermentation during storage period and to reduce the occurrence of pathogenic bacteria by the suppression of their growth.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.372-379
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• 2016

This study was performed to investigate the quality characteristics of various salted (8, 10, and 12%) Doenjang prepared with fermented Hwangchil (Dendropanax morbifera) extract as well as the effect of Bacillus methylotrophicus S8 strain, isolated from soy sauce, as a starter culture. After fermentation, the total cell number of low-salted Doenjang (8% and 10%) prepared with fermented Hwangchil was lower than that of Doenjang without fermented Hwangchil. Low-salted Doenjang (8% and 10%) showed higher total acidity, amino acid, and organic acid levels as well lower pH levels than high-salted Doenjang (12%), indicating active fermentation. The highest levels of lactic acid (48.1 mg/L) and glutamic acid (549.0 mg/L) were observed in low-salted Doenjang (8%) fermented with B. methylotrophicus S8 strain. The low-salted Doenjang (8%) fermented with B. methylotrophicus S8 also showed the highest score in overall preference of sensory evaluation. These results indicate that Hwangchil extract fermented with B. methylotrophicus S8 can be used as a starter for making low-salted Doenjang, resulting in improved palatability, and inhibition of abnormal fermentation.