• Title/Summary/Keyword: mixed-culture

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Adjustment Factors for Family Life of Multi Cultural Family Couples (다문화가정 부부의 가정생활 적응 요인에 대한 연구)

  • Kang, Ki-Jung;Chung, Chun-Seok
    • Korean Family Resource Management Association
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    • v.13 no.2
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    • pp.153-167
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    • 2009
  • This research analyzes factors of family life adjustment in mixed-culture families through a focus group and individual interviews with nine mixed-culture couples eighteen people who live in city C. First, the reason that women of other cultures wants to marry Korean men is because they find it a good opportunity, as they expect that Korean husbands will take responsibility of their family. On the other hand, Korean men also expect that they would have some similarities to each other. Also, in southeastern Asian men have more freedom than women to choose an international marriage in Southeastern Asia. Second, mixed-culture couples in everyday life are affected by communication problems, cultural differences, natural environment, financial situation, male -dominant attitude, self-adjustment pressure, house-work role and financial support from their own country. Third, wives from other cultures ask for social support to adjust in Korea and make a healthy family. These women can be important, as they have their own role in the family even though they may be far from their mother in law's strong expectation in how well she can adopt Korean culture.

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Studies on the mixed culture of Lactobacillus helveticus and Streptococcus thermophilus in milk - Growth characteristics and cultural conditions for the mixed culture - (Lactobacillus helveticus와 Streptococcus thermophilus의 혼합배양에 관한 연구 -생육특성 및 배양조건-)

  • 윤성식;박정길;유주현
    • Microbiology and Biotechnology Letters
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    • v.13 no.2
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    • pp.151-156
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    • 1985
  • To investigate the new Yoghurt starter, Lactobacillus helveticus YM-1, which was selected among 14 Lactobacillus strains, and Streptococcus thermophilus CH-1 were inoculated together in reconstituted non-fat skim milk medium and their growth characteristics and cultural conditions for the mixed culture were examined. The main results of this study were obtained as follows. The typical symbiotic growth was shown between the two strains and pH and temperature for optimal growth were 6.5 and 4$0^{\circ}C$, respectively. Heat treatment of milk was most effective at 10$0^{\circ}C$ for 30 min. The cell-free filtrate of Lactobacillus helveticus YM-1 had stimulatory effect on Streptococcus thermophilus CH-1 but the reverse case was slightly observed. Significant difference was observed in the proteolytic activities between Lactobacillus helveticus YM-1 and Streptococcus thermophilus CH-1. The former liberated 135$\mu\textrm{g}$ free amino acid per $m\ell$ of cultured milk, the latter 35$\mu\textrm{g}$ per $m\ell$.

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The Effects of Lactic Acid Bacteria on the Growth and Aflatoxin $B_1$ Production of Aspergillus parasiticus (유산균이 Aspergillus parasiticus의 성장과 Aflatoxin $B_1$ 생성에 미치는 영향)

  • Lee Kyung-Min;Kim Jong-Gyu
    • Journal of Environmental Health Sciences
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    • v.31 no.2
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    • pp.127-133
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    • 2005
  • This study was performed to investigate the competitive effect of Leuconostoc mesenteroides and Lactobacillus plantarum on the growth and aflatoxin $B_1$ production of Aspergillus parasiticus. Leu. mesenteroides and Lac. plantarum were grown with A. parasiticus in a modified APT broth at $28^{\circ}C$ for 9 days. It was observed that the growth of A. parasiticus got lower when the two bacteria were inoculated simultaneously than when the mold grew alone. The pH of mixed culture of Leu. mesenteroides and Lac. plantarum showed significantly lower value than the pH of the pure culture of A. parasiticus (p<0.05). The acidity of the mixed culture group significantly increased compared with the control group (A. parasiticus alone group) (p<0.05). The aflatoxin $B_1$ production was significantly decreased in the mixed culture group than in the A. parasiticus alone group (p<0.05). Leu. mesenteroides showed the more efficient effect than Lac. plantarum. These results indicate that the two lactic acid bacteria have inhibitory effect on the growth and aflatoxin $B_1$ production of Aspergillus parasiticus.

Study on the 2,4,6-Trinitrotoluene reduction rate by mediation of extracellular material of mixed culture (혼합배양 미생물의 세포외 물질이 2,4,6-Trinitrotoluene 변환에 미치는 영향에 관한 연구)

  • 한기봉
    • Journal of environmental and Sanitary engineering
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    • v.11 no.2
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    • pp.27-31
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    • 1996
  • 2,4,6-Trinitrotoluene(TNT) was reduced into intermediate products by mixed culture incubated in anaerobic condition. To test the effects of extracellular material to electron transfer between sulfide and TNT, filtered medium of mixed culture was loaded in the test tubes with TNT and sulfide. The transformation rate was measured under four different conditions. The rate under microbial activity was the fastest among under different conditions. With sulfide or filtrate alone and TNT, the reactions were measured as the slowest reactions or no reactions occured, respectively. The reaction rate coefficient were calculated by linear regression and the first order kinetic was fitted best. Also, the plot of rate coefficients (K$_{f}$) showed linear relationships when at time zero TNT and sulfide concentration were 20 mg/1 and 6.0 mM, respectively. By extrapolation, reaction rate coefficient of 100% filtrate could be calculated as 0.0054/minute. However, reaction rate was affected by different concentration of sulfide, so it is a dependent of sulfide concentration. The results of this test showed TNT reduction rate can be limited more by microbial reaction than by mediation of filtrate or sulfide and filtrate alone.

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유사 생합성 경로를 가진 Streptomyces sp.의 혼합배양을 이용한 Doxorubicin 생합성

  • Choi, Yun-Hwa;Hong, Young-Soo;Lim, Jai-Yun;Lee, Jung-Joon
    • 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.

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Butyric Acid Fermentation of Sodium Hydroxide Pretreated Rice Straw with Undefined Mixed Culture

  • Ai, Binling;Li, Jianzheng;Chi, Xue;Meng, Jia;Liu, Chong;Shi, En
    • Journal of Microbiology and Biotechnology
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    • v.24 no.5
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    • pp.629-638
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    • 2014
  • This study describes an alternative mixed culture fermentation technology to anaerobically convert lignocellulosic biomass into butyric acid, a valuable product with wide application, without supplementary cellulolytic enzymes. Rice straw was soaked in 1% NaOH solution to increase digestibility. Among the tested pretreatment conditions, soaking rice straw at $50^{\circ}C$ for 72 h removed ~66% of the lignin, but retained ~84% of the cellulose and ~71% of the hemicellulose. By using an undefined cellulose-degrading butyrate-producing microbial community as butyric acid producer in batch fermentation, about 6 g/l of butyric acid was produced from the pretreated rice straw, which accounted for ~76% of the total volatile fatty acids. In the repeated-batch operation, the butyric acid production declined batch by batch, which was most possibly caused by the shift of microbial community structure monitored by denaturing gradient gel electrophoresis. In this study, batch operation was observed to be more suitable for butyric acid production.

Quantitative Polymerase Chain Reaction for Microbial Growth Kinetics of Mixed Culture System

  • Cotto, Ada;Looper, Jessica K.;Mota, Linda C.;Son, Ahjeong
    • Journal of Microbiology and Biotechnology
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    • v.25 no.11
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    • pp.1928-1935
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    • 2015
  • Microbial growth kinetics is often used to optimize environmental processes owing to its relation to the breakdown of substrate (contaminants). However, the quantification of bacterial populations in the environment is difficult owing to the challenges of monitoring a specific bacterial population within a diverse microbial community. Conventional methods are unable to detect and quantify the growth of individual strains separately in the mixed culture reactor. This work describes a novel quantitative PCR (qPCR)-based genomic approach to quantify each species in mixed culture and interpret its growth kinetics in the mixed system. Batch experiments were performed for both single and dual cultures of Pseudomonas putida and Escherichia coli K12 to obtain Monod kinetic parameters (μmax and Ks). The growth curves and kinetics obtained by conventional methods (i.e., dry weight measurement and absorbance reading) were compared with that obtained by qPCR assay. We anticipate that the adoption of this qPCR-based genomic assay can contribute significantly to traditional microbial kinetics, modeling practice, and the operation of bioreactors, where handling of complex mixed cultures is required.

Development of a Mixed-culture Fermentation Process and Characterization for New Oligosaccharides and Dextran Using Lipomyces starkeyi and Leuconostoc mesenteroides (Lipomyces starkeyi와 Leuconostoc mesenteroides의 혼합배양에 의한 올리고당과 Dextran의 생성 및 생성당의 특성 연구)

  • 허수진;김도만;이인수;장판식
    • Microbiology and Biotechnology Letters
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    • v.27 no.4
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    • pp.304-310
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    • 1999
  • We have developed a new process for the production of new structure oligosaccharides using the mixed-culture fementation of Lipomyces starkeyi KSM22 and leuconostoc mesenteroides B-512FMCM.L.starkeyi KSM22 produces a novel DXAMase(an enzyme containing both dextranase and amylase activities). It hydrolyzes the soluble starch and dextran. The hydrolyzates were used as acceptors for dextransucrase of L.mesenteroides to synthesize the new oligosaccharides(NOS). In fermentation, as the concentration of sucrose was increased from 9%(w/v) to 15%(w/v), the yields of dextran(sum of dextran I, MW=66kD, and dextran II, MW=21kD) was increased from 12.7% to 42.5%, and NOS was increased from 3.9% to 5.2% of the theoretical, respectively. The NOS of dp(degree of polymerization) 5 and over was increased from 33.1% to 58.3% of the total NOS. The NOS showed heat resistant up to 12$0^{\circ}C$ and was stable at pHs ranged from 2 to 6. The NOS decreased the pH changes in the culture of S. mutans, and also showed inhibitory effects on the growth of S. aureus or S. typhimurium.

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Changes of Oligosaccharide in Soymilk with Mixed Cultures of Lactobacillus acidophilus and Saccharomyces uvarum (Lactobacillus acidophilus와 Saccharomyces uvarum의 혼합배양에 의한 대두유의 당 변화)

  • Kong, In-Soo;Kong, Jai-Yul;Yu, Ju-Hyun
    • Korean Journal of Food Science and Technology
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    • v.24 no.6
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    • pp.586-591
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    • 1992
  • The oligosaccharide metabolism in soymilk was investigated by mixed culture with Lactobacillus acidophilus and Saccharomyces uvarum. When Saccharomyces uvarum was cultured in soywhey, change of oligosaccharide could be shown apparently. However, Lactobacillus acidophilus could not utilize oligosaccharide in soywhey for growth and lactic acid production. During the fermentation of mixed culture with Lactobacillus acidophilus and Saccharomyces uvarum, Saccaharomyces uvarum was supposed to convert oligosaccharide to monosaccharide first and then Lactobacillus acidophilus to convert these produced monosaccharide to lactic acid.

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Fermentation characteristics of persimmon wine by the mixed culture of Pichia anomala JK04 and Saccharomyces cerevisiae Fermivin cells (Pichia anomala JK04와 Saccharomyces cerevisiae Fermivin의 혼합발효에 의한 감와인의 발효 특성)

  • Kwon, Soo-Jin;Choi, Jun-Su;Yeo, Soo-Hwan;Park, Heui-Dong
    • Korean Journal of Food Preservation
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    • v.22 no.5
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    • pp.768-777
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    • 2015
  • Persimmon contains high levels of vitamins and phenolic compounds, as well as soluble solids, necessary for the fermentation of persimmon wine. Co-fermentation of persimmon wine was carried out using a mixed culture of Pichia anomala JK04, a Korean indigenous yeast that improves wine quality and flavor, and Saccharomyces cerevisiae Fermivin, an industrial wine yeast, in the following ratios: 9:1 (v/v), 5:5 (v/v), 1:9 (v/v) and 0:10 (v/v). During fermentation, the alcohol contents increased more slowly in samples of mixed culture than in samples of the single culture of S. cerevisiae Fermivin. The alcohol contents of all samples reached 12~13% (v/v) after 15 days. All samples of the mixed culture showed greater variety in flavor and taste than S. cerevisiae Fermivin only. In the sensory evaluation, mixed culture samples had higher scores in terms of flavor and overall preference than the single culture samples. Therefore, P. anomala JK04 is thought to improve the wine flavor of Korean domestic persimmon wine.