• Microbiology and Biotechnology Letters
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• v.25 no.6
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• pp.580-585
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• 1997

We selected two mutants namely strain D5 and Nu23 by mutagenesis of anthracycline producing Streptomyces: the former is an $\varepsilon$-rhodomycinone overproducing mutant selected from Streptomyces sp. C5, a baumycin producer and the latter, a blocked mutant of early pathway for doxorubicin biosynthesis obtained from Streptomyces peucetius ATCC 27952, a doxorubicin producer. The mutant strain Nu23 does not produce anthracycline metabolites but retains the most of enzyme activities converting aklavinone to doxorubicin and the mutant strain D5 produced $\varepsilon$-rhodomycinone at a level of 150 $\mu$g/ml. These strains were grown separately in NDYE medium and each was mixed at day 3 by equal volume of culture broth but the quantity of doxorubicin produced was far below an estimation based on the level of $\varepsilon$-rhodomycinone normaly produced by the strain D5. On the other hand doxorubicin was reached at maximum level after 4 days in the mixed culture condition which was composed of culture broth of strain D5 grown for 6 day and that of strain Nu23 grown for 3 day. It was turned out that the growth of mutant strain D5 was inhibited by the accumulation of daunorubicin and doxorubicin in mixed culture broth, which cause the limitation of $\varepsilon$-rhodomycinone.

• Culinary science and hospitality research
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• v.13 no.1 s.32
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• pp.55-61
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• 2007

This study was carried out to evaluate the growth characteristics of Lactobacillus acidophilus KCCM 32820 and Propionibacterium freudenreichii KCCM 31227 and the production of propionic and acetic acids in 5% and 10% whey broth by mixed culture of L. acidophilus KCCM 32820 and P. freudenreichii KCCM 31227. Exponential phase of L. acidophilus KCCM 32820 was in the range of $6\sim12$ hrs and P. freudenreichii KCCM 31227 was in the range of $36\sim108$ hrs. In the mixed culture, production of propionic acid was shown to be greater value in the 10% whey broth than in the 5% whey broth and to be greater value in the low temperature for a long time than in sterilization by autoclave. Maximum production of propionic acid was 8.88 mg/mL in the 10% whey broth fermented at 120hrs. Production of acetic acid was revealed to be greater value in the 10% whey broth than in the 5% whey broth. The production quantity ratio of propionic acid to acetic acid was shown between $2:1\sim3:1$ during the fermentation process.

• Applied Biological Chemistry
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• v.36 no.5
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• pp.352-357
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• 1993

The effects of culture broth filtrates, sugar changes and utilizationon the growth and acid production of P. freudenreichii KFCC 31227and L. acidophilus KFCC 32825 were investigated in S.G.Y.(Skim milk, glucose, yeast extract) and SMW (skin milk whey)medium by the single and mixed cultures. The growth and acid production by mixed culture and in cultured broth filtrate of the other party were more affected than those of single culture and self-cultured broth filtrate. When the two strains were cultured, P. freudenreichii KFCC 31227 utilized with lactose more than glucose and L. acidophilus KFCC 32825 was glucose more than lactose in the growth and acid production. The mixed culture of two strains was more affected to sugar utilization than single culture. This result was considered due to the synergistic effect by interaction of these two strains in mixed culture.

• Journal of the Korean Society of Food Culture
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• v.18 no.6
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• pp.584-591
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• 2003

The objective of this study is to develope natural and economical Naengmyun broth using stock prepared with chicken heads. Proper mixing ratio of chicken head stock and chicken breast broth was determined through the sensory evaluation. In order to find out the attributes of chicken head-chicken breast broth(CH-CB broth), chicken breast broth and beef brisket(BB) broth were mixed to the chicken head stock and compared the preference and chemical elements between the broths were compared. The appropriate mixing ratio for reinforcing the meat broth and savory flavor, of was determined to 3:7(w:w). The comparison of CH-CB broth's and CH-BB broth's elements showed that the amount of crude protein and ash was the same and, in the case of crude lipid, CH-BB broth had 0.01% more than CH-CB broth. In the case of the total amount of free amino acids, CH-CB broth had 1.6 times more than CH-BB broth. A survey with 50 consumers showed that was prefered between CH-CB broth and CH-BB broth. CH-CB broth with significance.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.683-688
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• 1998

This study was conducted to develop optimal composition of flour brew in order to economically utilize flour brew inoculated by lactic acid bacteria as a starter(mother sponge) in bread-making. Two flour brews were prepared ; one with flour and water, the other with flour, water and NaCl. Various nutrients were added to both flour brews and Lactobacilli deMan Rogosa and Sharpe (MRS) broth to investigate the effect of them on growth and activities of Streptococcus thermophilus, Lactobacillus brevis and their mixed culture in flour brews to be tested with incubation at 37$^{\circ}C$. The growth of Streptococcus thermophilus, Lactobacillus brevis and their mixed culture was stimulated by addition of NaCl with 0.85% concentratin and more by mixed culture than by single lactic acid bacteria, resulting in 3 hrs reduction in cultivation and more by mixed culture than by single lactic acid bacteria, resulting in 3 hrs reduction in cultivation time. the addition of 3% glucose to flour brew with NaCl was observed to enhance acid productioni by mixed culture. Yeast extract greatly affected growth and activities of mixed culture of lactic acid bacteria in flour brew with NaCl and its optimum level of this additive in flour brew with NaCl was approximately 1.0%. The optimal composition of flour brew for mixed culture of lactic acid bacteria was suggested as follows; flour 100g, water 300g, NaCl 3.46g, glucose 12.48g, yeast extract 3.46g.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.549-557
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• 2000

Dental caries is a bacterial disease of the dental hard tisssus, characterized by a localized, progressive, molecular disintegration of tooth structure. The action of Leuconostoc lactis 51 about plaque formation and replication by Streptococcus mutans was studied as follows. 1. Lower amount of plaque was produced at the mixed culture of S. mutans and L. lactis 51 than S. mutans alone on the wires in the beaker. 2. Fewer cells of S. mutans were replicated at the mixed culture of S. mutans and L. lactis 51 than S. mutans alone. 3. In M17Y broth, viable cells of S. mutans and L. lactis 51 increased for 12 hours, and decreased for 24 hours. In M17YS broth, viable cells of S. mutans showed time-dependent decrease at mixed culture of S. mutans and L. lactis 51. 4. The culture supernatant of L. lactis 51 didn't inhibit the replication of S. mutans and the formation of artificial plaque. 5. Sucrose and frutose were extracted from the culture supernatant of L. lactis 51 in M17YS broth. These results suggest that L. lactis 51 isolated from the oral cavity inhibits the replication of S. mutans and the formation of artificial plaque.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.430-436
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• 1992

Hydrogen evolution by mixed fermentation of Clostn"dium butyn"cum and photosynthetic bacteria which were capable of consuming clostridial metabolites and evolving hydrogen was investigated. Acetate and butyrate formed from anaerobic clostridial fermentation were efficiently utilized by Rhodopseudomonas sPhaeroides K-7. For complete bioconversion of clostridial metabolites such as acetate and butyrate into hydrogen, mixed culture of both anaerobic organisms forming molecular hydrogen was performed. By the mixed culture, the yield of hydrogen production increased by 20 to 75% and the levels of clostridial metabolites such as acetate, butyrate decreased in the fermentation broth. Influence of cell mixing ratio. mixing time and inoculum level on hydrogen evolution by mixed culture were examined. And then cometabolic pattern compared with in pure culture was observed as time course.

• KSBB Journal
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• v.23 no.3
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• pp.199-204
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• 2008

Culture conditions for biological hydrogen production were investigated in wastewater of Takju manufacturing factory. Rhodobacter spaeroides KCTC1425, photosynthesis bacteria, and Enterobacter cloacae YJ-1, anaerobic bacteria were used. The hydrogen production were $195.3m{\ell}{\cdot}H_2/{\ell}$ broth for Rhodobacter spaeroides KCTC1425 and $271.8m{\ell}{\cdot}H_2/{\ell}$ broth for Enterobacter cloacae YJ-1 during 36 h. The hydrogen production increased with light intensity, and were highest over 12000Lux. In mixed culture of Rhodobacter spaeroides KCTC1425 and Enterobacter cloacae Y J-1, the optimum mixing ratio of hydrogen production was 20 and 80. Adding volume of yeast extract for maximum hydrogen production was 15 $g/{\ell}$, but there was no effect over that. $Na_2MoO_4$ was most effective among the inorganic salts, and the optimum volume was 0.4 $g/{\ell}$. In semi-continuous culture, total hydrogen production was $13086m{\ell}{\cdot}H_2/{\ell}$ broth for 144 h with operating period of 24 h.

• KSBB Journal
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• v.23 no.2
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• pp.158-163
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• 2008

In this study, we have investigated the antibacterial, antioxidant, and antitumor activities of mycelium cultural extract from mushroom. Mushroom mycelium was grown in a synthetic liquid media such as PD broth, YM broth or citrus extracts. In antibacterial activity test, the best result was achieved when mycelium cultural extracts from Phellinus linteus and Coriolus versicolor were incubated together on YM broth. On the other hand, mushroom mycelium cultured on citrus extracts showed better activity than that on PD broth. We have also tested the antioxidant activity at concentration up to 10 mg of mycelium cultural extract/mL. The more it is in higher concentration, the more the activity increases. The higher antioxidant activity was observed both on PD broth containing the Phellinus linteus and Coriolus versicolor mycelium and citrus extract containing the same. The complex culture extracts obtained from the synthetic medium and citrus extract medium showed 10-89% of the 1,1-diphenyl-2-picrylhydrazyl radical scavenger activity. The antitumor activity of mycelium cultural extract was examined by using MTT assay on A549 cells. Mushroom mycelium cultured on citrus extracts showed interestingly higher antitumor activity than that on synthetic liquid media.

• Korean Journal of Food Science and Technology
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• v.19 no.1
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• pp.42-49
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• 1987

The acid production and sugar utilization of Lactobacillus helveticus YM-1 between Streptecoccus lactic ${ML}_3$ were investigated in skim milk, cultured broth filtrate and semi-synthetic medium. The effect of acid production by mixed culture and in cultured broth filtrate of the other party were more than that of single culture and self-cultured broth filtrate. When the two strains were cultured 12 hrs, Streptococcus lactis ${ML}_3$ utilized with 0.4% lactose, Lactobacillus helveticus YM-1 with 0.85%, and mixed strains with 1.05% respectively. In 8 hrs fermentation Lactobacillus helveticus YM-1 and mixed strains accumulated 0.22%, 0.10% glucose in the medium respectively, and then decreased gradually. The glucose released by Lactobacillus helveticus YM-1 was stimulated the acid production of Streptococcus lactis ${ML}_3$.