• Microbiology and Biotechnology Letters
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• v.46 no.1
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• pp.1-8
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• 2018

Gul (oyster) jeotgals (GJs) were prepared using different types of salt (23%, w/v): purified salt, solar salt aged for 3 years, and bamboo salt crystalized 3 times. One set of GJs was fermented with Bacillus subtilis JS2 ($10^6CFU/g$), while the other GJ set was fermented without starter. During fermentation for 24 weeks at $15^{\circ}C$, the starter GJs showed 10-fold higher bacilli counts than the no-starter GJs, where the maximum bacilli count was $8{\times}10^3CFU/g$. All 28 bacilli strains isolated from the 6-week GJs were identified as B. subtilis by using a RAPD-PCR, indicating that some of the B. subtilis JS2 cells remained viable. Lactic acid bacteria (LAB) and yeasts were present at low levels, $10^1-10^2CFU/g$. LAB with protease activities isolated from 10-week samples were identified as Enterococcus species. The isolates obtained at 16 weeks were all Staphylococcus species. The GJs with bamboo salt showed higher pH and lower titratable acidity (TA) values than the other GJs due to the strong alkalinity of bamboo salt. The amino-type nitrogen in the GJs increased slowly during the fermentation. At 24 weeks, the GJs with purified salt showed the highest amino-type nitrogen (412-430 mg%), followed by the GJs with solar salt (397-406 mg%) and GJs with bamboo salt (264-276 mg%). Meanwhile, the GJs with bamboo salt showed the highest ammonia-type N (63.67 mg%), followed by the GJs with purified salt (49 mg%) and solar salt (48 mg%).

• The Korean Journal of Food And Nutrition
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• v.7 no.2
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• pp.151-158
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• 1994

This study was carried out to clear up the cause of low-acid producing phenomenon occurred In non-fat dry milk during liquid-yoghurt fermentation by Lactobacillus case, and to present its improving methods. All samples of non-fat dry milks which were low in TCA-soluble peptides showed low-acid production, but those high in TCA-soluble peptides showed high-acid production. The addition of trypsin-hydrolysate of Na-caseinate to non-fat dry milk showed some improving effect on acid production but that of papain-hydrolysate did not show any improving effect and that of bacterical neutral protease-hydrolysate showed some inhibitory effect. The improving effects on growth and acid production of lactic acid bacteria were more prominent when the trypsin-hydrolysate of Na-caseinate was added. to such fermenting system in which the levels of TCA-soluble peptides and the proteolytic ability of starter bacteria were abnormally low. The liquid-yoghurt made with non-hydrolysed Na-caseinate and defective non-fat dry milk showed precipitate occurrence but that with trypsin-hydrolysate of Na-caseinate and defective non-fat dry milk did not make any precipitate during storage as with normal non-fat dry milk.

• Food Science and Preservation
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• v.24 no.2
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• pp.187-195
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• 2017

This study evaluated quality characteristics of soybean fermented by selected lactic acid bacteria, which were the enzyme strains with high antimicrobial activities isolated from traditionally prepared soybean paste. We determined total aerobic and lactic acid bacteria counts, protease and amylase activities, reducing sugar and amino-type nitrogen contents, and the amounts of amino acids, organic acids, and aroma-compounds. The total aerobic bacteria counts in soybean fermented with strain I13 ($7.75{\times}10^9CFU/mL$) were the highest among all the strains analyzed. Lactic acid bacteria numbers were $2.85{\times}10^9$ to $4.35{\times}10^9CFU/mL$ in soybean fermented with isolates. Amylase and protease activities of the JSB22 sample were the highest among all sample. Reducing sugar and amino-type nitrogen contents of soybean fermented with JSB22 (1.23%, 94.52 mg%) were highest. Total amino acid content of the samples was 15.88-17.62%, and glutamic acid, aspartic acid, leucine, lysine, and arginine were the major amino acids. Lactic acid (0.82-3.65 g/100 g), oxalic acid (22.74-63.57 mg/100 g), and fumaric acid (2.88-6.33 mg/100 g) were predominant organic acids. A total of 39 volatile aroma-compounds were identified, including 2 esters, 5 ketones, 7 alcohols, 14 hydrocarbons, 2 heterocyclic compounds, 4 acids, and 5 miscellaneous compounds. These results represent useful information for the development of a starter (single or complex) and will be used for production of functional fermented soybean foods.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.386-390
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• 1993

Addition of starch syrup, table sugar, potato powder, skim milk powder an parched soybean powder to melon flesh was suitable as fermented melon base. The manufacturing process of fermented melon was as follows: Pasteurization for 10 min at $95^{\circ}C$, use of 1% starter culture, fermentation for 12 hours at $35^{\circ}C$ and ripening for 3 days at $8^{\circ}C$. The growth and acid production of Pediococcus acidilactici among several starter cultures were most active for the first 12 hours, but such activities were disappeared during ripening. In the case of Lactobacillus plantarum, the activities were not high during fermentation, which, however, increased during ripening. Throughout the whole manufacturing process, the fermented melon with a mixed culture of P. acidilactici and L. plantarum showed more cell number of each bacterium and higher titratable acidity than that with single cultures. Also P. acidilactici surpressed the growth of L. plantarum during ripening.

• Journal of Dairy Science and Biotechnology
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• v.16 no.2
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• pp.83-89
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• 1998

Studies on the antimutagenicity of Lactobacillus spp. and Bifidobactrium spp. against 2-nitrofluorene have been conducted utilyzing Salmonella typhimurium TA 98 in order to characterize the activity by the starter and non-starter strains. The average antimutagenic activity of Lactobacillus spp. and Bifidobactrium spp. against 2-nitrofluorene was 20.29% and L. plantarum CU 722 revealed the greatest mutation inhibition activity of 50.34%. An intensive antimutagenicity was found in the cell wall and cytoplasm fraction of L. plantarum CU 722 in skim milk culture showing inhibition rate of 34.9% and 24.5% respectively and very low activity remained in cell free broth and in lactic acid. The optimum cultivation time for Lactobacillus spp. and Bifidobacterium spp. to inhibit mutation was 24 hours and the optimum preincubation time of the reaction mixture containing the mutagen, lactic culture and indicator strain was 60 minutes, and the optimum incubation time for the test plates was 48 hours.

• Food Science and Preservation
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• v.23 no.7
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• pp.1050-1057
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• 2016

This study was carried out to investigate the effectiveness of Leuconostoc mesenteroides isolated from octopus baechu kimchi as a potential starter for seafood kimchi. L. mesenteroides is lactic acid bacterium currently used as a starter for kimchi production. We selected the most effective L. mesenteroides strain from the 7 strains isolated from octopus baechu kimchi and, based on biochemical properties and 16S rRNA sequencing, identified the selected strain as L. mesenteroides SK-1. The SK-1 strain exhibited acid-tolerance, good survival capacity, and excellent dextran productivity. We investigated the effects the SK-1 of starter on seafood kimchi fermentation. Octopus baechu kimchi was fermented with L. mesenteroides SK-1 at $4^{\circ}C$ for 35 d. The decrease in pH and increase in acidity in octopus baechu kimchi fermented with the SK-1 starter occurred more quickly than that in the control kimchi indicating that. Octopus baechu kimchi with SK-1 starter has a relatively slow rate of increase in lactic acid production. As a result, octopus baechu kimchi prepared with L. mesenteroides SK-1 can be maintained at a suitable ripening degree over an extended period of time compared to that of the control kimchi, Moreover, the octopus baechu kimchi started with L. mesenteroides SK-1 has excellent sensory properties, including a refreshing taste, and a weak sour odor.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.116-122
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• 2004

Growth of Lactobacillus acidophilus in flour was investigated for production of noodle and bread. L. acidophilus grew when fermented in flour, and growth continued upon fermentation with salt for 72 hr. pH of L. acidophilus-fermented flour with salt decreased up to 72 hr, reaching 3.06. Fermented flour with salt showed no decomposition as compared to that without salt. In flour fermented by L. acidophilus, amounts of lactic and acetic acids produced increased with incubation time, and reached, after 72 hr incubation, 6,821 and 0.191 mg/g, respectively, resulting in significantly higher production of lactic acid. Viscosity of fermented flour with salt increased, whereas that without salt decreased with incubation time. Results reveal L. acidophilus-fermented flour with salt could be applied as effective agent in noodle and bread productions.

• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.220-233
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• 2019

Bacterial lysates have become a common ingredient for natural health care. Lactic acid bacteria (LAB) could serve as potential candidates for lysate production: the lactic acids produced by LAB have been utilized for their moisturizing, antimicrobial, and rejuvenating effects, while other substances provide topical benefits and health effects for the skin. Our study aimed to obtain lysate from a LAB S. macedonicus MBF 10-2 through an optimized fermentation using the Response Surface Methodology. Strain MBF10-2 was cultivated in a 2L fermenter tank in de Man Rogosa and Sharpe (MRS) medium and in plant-based peptone modified MRS, i.e. Soy-peptone and Vegitone. The duration and the medium composition (dextrose and soy peptone or proteose peptone) were adjusted to obtain an optimum production of cell lysate. Central Composite Design was employed for Design Expert 7.0.0 by adjusting 3 factors: dextrose (1%, 1.5%, 2%, 2.5%, 3%), soy or proteose peptone (0.5%, 0.75%, 1%, 1.25% and 1.5%), and duration of fermentation (8, 10, 12 14, and 16 h for MRS-Soy peptone and 15, 17, 19, 21, and 23 h for MRS Vegitone). Bacteriocin-Like Inhibitor Substance activity of lysate and pH were used as indicators. The optimum condition for lysate production using MRS Soy Peptone and Vegitone are as follows: dextrose concentration 2.5%, plant-based peptone 1.25%, while optimum fermentation duration were 11.18 h (MRS Soy Peptone) and 17 h (MRS Vegitone) with a starter concentration of 10% at $OD_{600nm}$ $0.2{\pm}0.05$. However, the standard MRS medium produced better quality lysate compared to MRS plant-based peptones.

• The Korean Journal of Food And Nutrition
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• v.25 no.3
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• pp.505-512
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• 2012

This study evaluated the quality characteristics of rice-doenjang prepared with Aspergillus oryzae MD05 and Bacillus subtilis HJ18-4. The physicochemical characteristics of rice-doenjang prepared with three types of meju, such as grain type(Rice 1), disc shape(Rice 2), and brick shape(Rice 3), were compared. We determined amino and ammonia nitrogen contents, protease and amylase activities, reducing sugar content, and total aerobic counts and lactic acid bacteria counts. The amino nitrogen and reducing sugar contents in all meju types gradually increased during fermentation. The amino nitrogen contents reached 151.5~200.0 mg%. Rice 3 were had the highest levels among the 4 types of rice-doenjang. After 42 days of fermentation, amylase and protease activity of Rice 3 were 366.57 and 94.26 unit/g, respectively, which were the highest levels among the 4 types of rice-doenjang. The total aerobic bacteria counts were not changed during 42-day fermentation. This results suggest that high quality characteristics of brick-shaped meju(Rice 3) were better than those of the other meju preparations.

• Food Science of Animal Resources
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• v.35 no.5
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• pp.683-691
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• 2015

The objective of this study was to identify the coccoidal bacteria present in 188 samples of fermented yaks’, mares’ and cows’ milk products collected from 12 different regions in Mongolia. Furthermore, we evaluated the fermentation properties of ten selected isolates of the predominant species, Streptococcus (S.) thermophiles, during the process of milk fermentation and subsequent storage of the resulting yoghurt at 4℃. Overall, 159 isolates were obtained from 188 samples using M17 agar. These isolates were presumed to be lactic acid bacteria based on their gram-positive and catalase-negative properties, and were identified to species level using 16S rRNA gene sequence analysis. These coccoid isolates were distributed in four genera and six species: Enterococcus (E.) durans, Enterococcus (E.) faecalis, Lactococcus (Lac.) subsp. lactis, Leuconostoc (Leuc.) lactis, Leuconostoc (Leuc.) mesenteroides. subsp. mesenteroides and S. thermophilus. Among these S. thermophilus was the most common species in most samples. From evaluation of the fermentation characteristics (viable counts, pH, titratable acidity [TA]) of ten selected S. thermophilus isolates we could identify four isolates (IMAU 20246, IMAU20764, IMAU20729 and IMAU20738) that were fast acid producers. IMAU20246 produced the highest concentrations of lactic acid and formic acid. These isolates have potential as starter cultures for yoghurt production.