• Food Science and Preservation
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• v.14 no.1
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• pp.94-99
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• 2007

To investigate the effects of Pichia anomala SKM-T and Galactomyces geotrichum SJM-59 on Baechu kimchi fermentation, lyophilized yeasts were added to Baechu kimchi and co-cultured at room temperature ($20{\pm}2^{\circ}C$) for 7 days. Desirable pH and acidity levels appeared by 3 days of fermentation in both the control culture and that with added G. geotrichum SJM-59. Furthermore, the culture with G. geotrichum SJM-59 sustained a desirable pH and acidity level until 5 days of co-culture. The pH of the culture with P. anomala SKM-T decreased slowly and was significantly higher than that of control throughout the experimental period. As fermentation time increased, the acidity of the culture with P. anomala SKM-T increased gradually. However, this culture maintained a desirable acidity level throughout the experiment. The number of lactic acid bacteria in the culture with P. anomala SKM-T was higher than in the culture with G. geotrichum SJM-59, or the control culture, throughout the experiment. The highest LA/TM ratio appeared after 3 nays of fermentation in the control culture, and on the 5 day of the yeasts added co-cultures. On sensory evaluation, no differences were detected between control and the culture with G. geotrichum SJM-59 arter 3 days of fermentation. The co-cultures with yeasts received high marks in umami taste. The co-culture with P. anomala SKM-T showed better texture properties than did the control culture. It was considered that fermentation times were delayed by addition of G. geotrichum SJM-59 or P. anomala SKM-T to Baechu kimchi fermentation.

• Korean journal of food and cookery science
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• v.21 no.5
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• pp.733-741
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• 2005

Waxy barley flour was fermented by two kinds of starter cultures; L. plantarum and L. brevis, alone or in combination and the effect was evaluated on waxy barley and wheat composite bread quality. In all three barley sourdoughs, fermentation decreased the pH, total sugar and reducing sugar, and increased lactic acid bacteria cell numbers. However yeasts (S. cerevisiae) were reduced. There was significant difference in physicochemical characteristics between the reference(composite barley dough containing improvement agent) and the barley sourdoughs (p <0.05). Barley sourdough fermented by L. plantarum showed more desirable farinogram properties of peak time, stability and elasticity than that of the reference. The rheofermentometer data for L. brevis produced the most $CO_2$ release curve, whereas L. plantarum held maximum $CO_2$ retention differed significantly from that of the breads made with barley sourdoughs fermented with the respectives starter cultures (p < 0.05). Barley sourdough bread fermented with L. plantarum resulted in better bread quality than the reference bread. The positive effect of fermentation with L. plantarum on bread quality was evident when comparing the well developed protein-starch matrix structure of the bread baked with barley sourdough with the reference bread.

• Journal of Microbiology
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• v.45 no.3
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• pp.246-255
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• 2007

Mutans streptococci have been implicated as cariogenic bacteria in dental caries because they can produce high levels of dental caries-causing lactic acid and extracellular polysaccharide. The aim of this study was to isolate and characterize the mutans streptococci from the dental plaque obtained from Koreans. The dental plaque samples were collected from the anterior and molar teeth of both jaws in 155 subjects (aged 2 to 33.2 years, average age $13.7{\pm}4.7\;years$). The samples were diluted by 100-fold in $1{\times}\;PBS$ and plated on mitis-salivarius bacitracin (MSB) agar plates. The mutans streptococci grown on MSB plates were screened by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) targeting dextranase gene (dex). The mutans streptococci were identified at the species level using a 16S rDNA sequencing comparison method. The biochemical tests were carried out to biotype the mutans streptococci. Ninety-five strains of the mutans streptococci out of 358 colonies, which were derived from 141 subjects, were isolated. Of them, 77 strains and 18 strains were Streptococcus mutans and Streptococcus sobrinus, respectively. The biotyping data showed that 62, 1, 20, 10, and 2 strains were biotypes I, II, IV, V and variant, respectively. Of the two strains of variant biotype, one strains was similar to biotype IV except that it was positive to the arginine hydrolysis test. We considered this one strain a new biotype, and classified it as biotype VII. In conclusion, S. mutans and its biotype I was most frequently isolated in Korean dental plaque. The mutans streptococci strains isolated in this study might be useful for the study of the pathogenesis and the prevention of dental caries.

• Food Science of Animal Resources
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• v.29 no.1
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• pp.15-23
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• 2009

In order to develop a new starter for fermented milk, 2082 bacteria were isolated from raw milk. The strain that showed excellent acid forming and ${\gamma}$-aminobutyric acid (GABA) production ($711.40{\mu}g/g$ D.W) characteristics after incubation at $37^{\circ}C$ for 18 hr was selected and identified as Lactobacillus acidophilus by the result of API carbohydrate fermentation pattern and 16S rDNA sequence. L. acidophilus RMK567 was investigated for its physiological characteristics. RMK67 strain showed good GABA production compared with commercial lactic acid bacteria. The optimum growth temperature of L. acidophilus RMK567 was $40^{\circ}C$ and cultures took 15 hr to reach pH 4.3. L. acidophilus RMK567 showed higher sensitivity to penicillin-G, novobiocin, as compared to other 14 different antibiotics. However, it showed more resistance to kanamycin, neomycin, streptomycin. It showed higher leucine arylamidase and ${\beta}$-galactosidase activities compared to 16 other enzymes. It was comparatively tolerant to bile juice and able to survive at pH 2 for 3 hr. It showed resistence to Escherichia coli, Salmonella typhimurium and Staphylococcus aureus with rates of 29.2%, 39.1% and 51.4%, respectively. Based on these and previous results, L. acidophilus RMK567 could be an excellent starter culture for fermented milk with excellent GABA contents.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.495-501
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• 1999

Lactobacillus acidophilus KY 2104 was isolated from 41 healthy korean ($2{\sim}35\;age$, 26 man, 15 woman) feces to use as a probiotic lactic acid bacteria for functional foods, fermented milk and pharmaceutical products. L. acidophilus KY 2104 survived in the presence of acid and bile, and inhibited pathogens. It survived almost 100% in pH 3.0 phosphate buffer for 2 hr, and more than $10^4\;cfu/mL$ in pH 2.0 phosphate buffer when inoculated by $10^7\;cfu/mL$. It was also found to grow in MRS medium containing 0.5% oxgall. L. acidophilus KY 2104 exerted inhibitory effect against enteric pathogens such as Escherichia coli, Shigella dysenteriae, Staphylococcus aureus and Salmonella typhimurium, when grown with each in associative cultures for 16 hr. As a result of acute toxicity of L. acidophilus KY 2104 in rats, there was no observation on motality, clinical signs, body weights and gross findings in the oral administration.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.419-424
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• 2002

Characteristics of curd yogurt containing maesil extract and flesh, and mixed cultures of lactic acid bacteria (Streptococcus thermophilus, Lactobacillus acidophilus, and L. casei) were investigated redundant. The results of sensory evaluation of curd yogurts containing maseil indicated that color, odor, taste, flesh amount, aftertaste, and overall acceptability of the 3% maesil extract crud yogurt added with 20% maesil flesh showed higher preference than others. The contents of free fatty acid and citric acid of curd yogurts added with 3% maesil extract were higher than the specify sample. The Hunter L (brightness) value of curd yogurt added with 3% maesil extract was not significantly different from the control curd yogurt, while the Hunter a (redness) and Hunter b (yellowness) values were higher. The hardness, adhesiveness, and gumminess of 3% maesil extract curd yogurts added with 20% maesil flesh were higher than others.

• Journal of Environmental Science International
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• v.23 no.5
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• pp.895-902
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• 2014

Bacterial cellulose (BC) has played important role as new functional material for food industry and industrial products based on its unique properties. The interest in BC from static cultures has increased steadily in recent years because of its potential for use in medicine and cosmetics. In this study, we investigated culture condition for BC production by Acetobacter sp. F15 in static culture. The strain F15, which was isolated from decayed fruit, was selected on the basis of BC thickness. The optimal medium compositions for BC production were glucose 7%, soytone 12%, $K_2HPO_4$ 0.2%, $NaH_2PO_4{\cdot}_2H_2O$ 0.2%, lactic acid 0.05% and ethanol 0.3%, respectively. The strain F15 was able to produce BC at $26^{\circ}C-36^{\circ}C$ with a maximum at $32^{\circ}C$. BC production occurred at pH 4.5-8 with a maximum at pH 6.5. Under these conditions, a maximum BC thickness of 12.15 mm was achieved after 9 days of cultivation; this value was about 2.3-fold higher than the thickness in basic medium. Scanning electron micrographs showed that BC from the optimal medium was more compact than plant cellulose and was reticulated structure consisting of ultrafine cellulose fibrils. BC from the optimal medium was found to be of cellulose type I, the same as typical native cellulose.

• Korean Journal of Food Science and Technology
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• v.17 no.5
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• pp.389-398
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• 1985

To shorten the processing of cheese slurry, four different slurries, ie, Control, Cheddar 1 and 2, and Italian-type that were made of Na-caseinates, cream, trace elements, lactic culture, and enzymes were fermented at $30^{\circ}C$ for 7days with daily stirring. PH, titratable acidity, soluble nitrogen, viable cell count, active SH groups, total volatile fatty acid, free fatty acid, electrophoretic patterns of degraded caseins, and viscosity were analyzed to investigate physicochemical properties of fermented slurries. Acid production was accelerated in the cheese slurries with protease than that without the enzyme and PH of the former was decreased after three days of fermentation to 4.90. The Change of titratable acidity agreed to PH patterns. Soluble nitrogen of the Control slurry was increased slowly for four days and then rapidly to 40% of total nitrogen while those containing protease to 70%. The protease of lactic cultures used (Streptococcus lactis and Streptococcus cremoris) broke down as-casein more rapidly than $\beta$-casein and most proteins were degraded to peptides and amino acids after three days of fermentation. Total volatile fatty acids were increased by added lipase and free fatty acids composition analyzed by GLC in cheddar slurry with 0.00001% lipase was similar to that of commercial cheddar cheese, while that in Italian-type slurry was a half of that in commercial Italian cheese. Active SH groups were increased in the cheese slurries with glutathione from fourth day of fermentation. The viscosity of slurries decreased very rapidly by addition of protease.

• Food Science of Animal Resources
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• v.28 no.1
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• pp.51-58
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• 2008

This study was performed to evaluate the physico-chemical properties of fermented sausages containing probiotic starter cultures (LK-30 plus, Lactobacillus plantarum 155 and 167, and Pediococcus damnosus L12) with reduced fat levels, and to determine the optimum condition for the manufacture of these products. Although low-fat fermented sausages were reduced fat content at the amount of 90% and the ripening time by 1-2 weeks, as compared to regular-fat counterpart, they became harder and had many winkles outside due to the extreme drying. In addition, fat level in fermented sausages affected the composition and shear force values. During ripening, pH, lightness and yellowness values tended to decrease, however, microbial counts of inoculated lactic acid bacteria were increased up to $10^8-10^9cfu/g$ within 3 days and remained constant thereafter. Low-fat fermented sausages had higher microbial counts than regular-fat ones. Although the inoculated probiotic starter cultures alone had the functional properties, such as cholesterol reduction, anti-high blood pressure and antimicrobial activity, they did not have distinctive characteristics in the fermented sausages. Based on these results, the low-fat fermented sausages were successfully manufactured, but a little bit increased fat level and improved functional properties in the fermented sausages would be required to have better quality as compared to regular-fat counterparts.

• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.265-276
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• 1999

This study was performed to evaluate the effect of hydrogen peroxide-producing Lactobacillus acidophilus V-20onthe replication of periodontal pathogens, Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. When A. actinomycetemcomitans and P. gingivalis were incubated alone and in the combination with L. acidophilus V-20, the viable cell numbers of A. actinomycetemcomitans and P. gingivalis were compared between those cultures. The effect of S. mutans, E. durans, and L. lactis on the replication of A. actinomycetemcomitans and P. gingivalis was also evaluated. The change of periodontal indexes(probine depth, gingival index, GCF volume) and the viable cell numbers of A. actinomycetemcomitans and black pigmented bacteroides in subgingival plaque sample were evaluated following gargling of fermented milk made from L. acidophilus V-20 for 1 month on patients with periodontal disease in maintenance phase. In the mixed culture of L. acidophilus V-20 and A. actinomycetemcomitans or P. gingivalis, the replication of A. actinomycetemcomitans or P. gingivalis wascompletely inhibited. But in the mixed culture of P. gingivalis and hydrogen peroxide-nonproducing Lactobacillus casei, the viable ceil numbers of P. gingivaliswas not decreased when compared with the numbers in the mixed culture of P. gingivalis and L. acidophilus V-20. In the mixed culture of A. actinomycetemcomitans and S. mutans, E. durans, or L. lactis, the viable cell number of A. actinomycetemcomitans was not almost changed when compared with the numbers in the culture of A. actinomycetemcomitans alone. And in the mixed culture of P. gingivalis and E. durans or L. lactis, the viable cell numbers of P. gingivaliswas not almost changed compared with the counts in the culture of P. gingivalis alone. But the replication of P. gingivalis was completely inhibited in the mixed culture of P. gingivalis and S. mutans. When the change of periodontal indexes following gargling of fermented milk was compared with baseline, probing depth and gingival index were not changed, but GCF volume was significantly decreased(p<0.05). And when the viable ceil numbers of microorganisms in subgingival plaque sample were compared with baseline, total viable ceil number was almost unchanged and the viable cell numbers of A. actinomycetemcomitans and black pigmented bacteroides were significantly decreased(p<0.05). These results suggest that L. acidophilus V-20 inhibit the replication of A. actinomycetemcomitans and black pigmented bacteroides by the formation of hydrogen peroxide.