• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.14-18
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• 1989

As the final experiment to assess the possibility of industrial application of FSC14-75, ethanol productivity from liquefied sweet potato starch was examined in a pilot scale of 300 liters. FSC14-75 produced 6.6％(v/v) of ethanol from 13.3％ of liquefied sweet potato starch in 8 days, and the residual sugar was 3.15％. The corresponding efficiency was 70％ of the theoretical maximum. Since we could isolate unicellular cell and flocculent cell from the fermentation broth, we designated them FSC14-75(S) and FSC14-75(F), respectively. We investigated ethanol productivity of FSC14-75(F) compared with that of FSC14-75(S) from liquefied potato starch in a mini·tar tormentor scale of 2.5 liters. FSC14-75(F) was found more favorable than the counterpart in terms of ethanol productivity, and produced 8.1％(v/v) of ethanol from 15％ of liquefied potato starch with an efficiency of 75％. In a pilot scale fermentation with 15％ of liquefied sweet potato starch, ethanol productivity of FSC14-75(F) reached maximum level of 7.7％(v/v) after 8 days, and the residual sugar was 1.9％. However, the ethanol productivity was not enhanced by a supplementary addition of Thermamyl to the fermentation broth after sterilization.

• KSBB Journal
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• v.11 no.3
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• pp.340-346
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• 1996

Variations of rheological properties of culture broth during the production of biopolymer by an alkali tolerant Bacillus sp. were investigated. Correlations among the rheological characteristics of culture broth, cell growth and biopolymer production were examined. Rheology of the culture broth changed in the course of fermentation. The culture broth showed a non-Newtonian flow behavior, as the viscosity and pseudoplasticsity increased during the cultivation. The rheological parameters such as flow index, consistency index, yield stress and apparent viscosity during the cultivation were not influenced by the cell growth, but significantly related to the biopolymer synthesis. Changes in the rheological parameters of the broth were affected not only by the biopolymer concentration, but also by the progress of fermentation. Some rheological parameters showed maximum values just before the completion of biopolymer production and substrate consumption. Hence, it was shown that the rheological characteristics of the culture broth could be used as a good indicator for the detection of the progress or completion of fermentation.

• Journal of Microbiology and Biotechnology
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• v.5 no.6
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• pp.309-314
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• 1995

Samples were collected from a commercial ethanol production plant to enumerate the bacterial contamination in each step of a starch based ethanol production process. Though the slurry of raw material used in the process carried bacteria with various colony morphology in the order of $10^4$ per ml, only the colonies of white and circular form survived and propagated through the processes to the order of $10^8$ per ml at the end of fermentation. Almost all of the bacterial isolates from the fermentation broth were lactic acid bacteria. Heterofermentative Lactobacillus fermentum and L. salivarius, and a facultatively heterofermentative L. casei were major bacteria of an ethanol fermentation. In a batch fermentation L. fermentum was more detrimental than L. casei to ethanol fermentation. In a cell-recycled fermentation, ethanol productivity of 5.72 g $I^{-1} h^{-1}$ was obtained when the culture was contaminated by L. fermentum, whilst that of the pure culture was 9.00 g $1^{-1} h^{-1}$. Similar effects were observed in a cell-recycled ethanol fermentation inoculated by fermentation broth collected from an industrial plant, which showed a bacterial contamination at the level of 10$^8$ cells per ml.

• Journal of Life Science
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• v.16 no.6
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• pp.938-941
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• 2006

Continuous fermentation process for the production of soluble glucan using mutant Agrobacterium sp. ATCC31750 has been developed in this research. When the concentration of soluble glucan was higher than 6 g/l, the viscosity of the fermented broth was too high and it needs complex separation process to separate from culture broth. Mathematical models which describe the cell growth and glucan production was developed and they kinetic parameters were estimated with experimental data. They are used for the optimization of continuous fermentation process and calculate optimal dilution rate for easy separation of glucan 4 g/l. With continuous fermentation, glucan production rate was increased 1.8 times more than that with batch fermentation.

• Mycobiology
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• v.42 no.2
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• pp.189-192
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• 2014

During a search for neuraminidase inhibitors derived from medicinal fungi, we found that the fermentation broth of Phellinus linteus exhibited potent neuraminidase inhibitory activity. Through bioassay-guided fractionation, two active compounds were purified from the ethyl acetate-soluble portion of the fermentation broth of P. linteus. These structures were identified as inotilone (1) and 4-(3,4-dihydroxyphenyl)-3-buten-2-one (2) by spectroscopic methods. Compounds 1 and 2 inhibited H1N1 neuraminidase activity with $IC_{50}$ values of 29.1 and 125.6 $125.6{\mu}M$, respectively, in a dose-dependent manner. They also exhibited an antiviral effect in a viral cytopathic effect reduction assay using MDCK cells. These results suggest that compounds 1 and 2 from the culture broth of P. linteus would be good candidates for the prevention and therapeutic strategies towards viral infections.

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.310-315
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• 2007

To investigate the effect of lactic acid bacteria in Andong-Soju fermentation and traditional nuruk maturation, several lactic acid bacteria were isolated from the Andong-Soju fermentation broth and traditionally matured nuruks using Lactobacilli MRS agar containing bromocresol purple. Among the isolated bacteria, ADS-L1 showed the highest lactic acid production and was dominant species in fermentation broth. Based on physiological characteristics and 16S rDNA sequencing results, the ADS-L1 was identified as Pediococcus acidilactici. The ADS-L1 grew well at $50^{\circ}C$, and under the acidic conditions at pH 4, whereas the ADS-L1 failed to grew by treatments of 12% (w/v) ethanol or 0.01N HCl. Considering the high temperature of nuruk above $50^{\circ}C$ during nuruk maturation and the high ethanol concentration of broth above 12% at the end-stage of Andong-Soju fermentation, these results suggested that the ADS-L1 is popular in matured nuruks and plays role in the early-stage of fermentation. Analysis of pH, brix, reducing sugar content, lactic acid production, and cell growth during the cultivation of ADS-L1 further suggested that the ADS-L1 may contribute the prevention of contamination by rapid and steady acidification of broth, and do not cause problems by rapid death at the end-stage of fermentation.

• Journal of the Korean Society of Industry Convergence
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• v.2 no.1
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• pp.77-83
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• 1999

Grown in the secondary broth of production media, the strain Streptomyces albulus has increased more the production of its metabolite ${\varepsilon}$-poly-L-lysine, one of poly(amino acid)s used as disinfecting food additives, than the strain in the primary culture of growth nutrients. Having the strain removed, the large concentrate obtained by ultrafiltrating the secondary culture broth. The concentrated production broth exchanged into followed by detecting in UV flowcell at 220nm the peptide bond of the components eluting the adsorbed proteins and polylysine with NaCl salt of gradient concentration, and has separated into five components. Among them the component in the fourth peak fraction has proved to be the pure ${\varepsilon}$-poly-L-lysine after the portion being hydrolyzed the fraction with HCl into amino acid followed by being the composing amino acid analysis.

• Journal of Ginseng Research
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• v.4 no.2
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• pp.121-132
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• 1980

In order to study the effect of Korean ginseng (Panax ginseng C. A. Meyer) components on acetic acid fermentation, ginseng extracts, sucrose, total can de saponins were added to the basal niedium respectively and surface culture was carried out at 30$^{\circ}C$. Lag ime, total acidity of the fermentation broth inhibitors and the degrees of inhibition were determined in tile course of fermentation . 1. Acetic acid fermentation was not inhibited by the addition of less than 1.93% of sucrose but the degree of inhibition was increased slightly by the addition of sucrose more than that. 2. Ginseng extract inhibited acetic acid fermentation slightly, and the degree of inhibition was similar to that of sucrose. Lag time was about 72 hours when a 20% of ginseng extract was added to the basal medium while that of the control was 22hours. 3. The free saponins inhibited acetic acid fermentation considerably, and the degree of inhibition of the saponins was about 400 folds of that of ginseng extracts. An increase of total acidity of the broth which contained 2.905% of the saponins was not observed even after one month. 4. It was presumed that some other components except saponins and sucrose in ginseng extracts counter the inbition effect of saponins on acetic acid fermentation

• KSBB Journal
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• v.28 no.6
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• pp.400-407
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• 2013

The growth characteristics and production of color pigments by Monascus strains were investigated during liquid culture, and production of monacolin K in red mold rice was carried out by solid state fermentation. Four different Monascus ruber strains were cultured in potato dextrose yeast extract broth (PDYB) media at $25^{\circ}C$ for 15 days. The high producing strain for red pigment was not corresponded to the strain for yellow pigment. Production of red pigment was high in the strain causing the fast pH change in culture broth. Production of monacolin K in red mold rice by solid state fermentation was influenced by a combination of wet cell weight and spore density in inoculum by liquid culture. Most strains showed the high production of monacolin K in red mold rice, when submerged fermentation was carried out for 5 days as inoculum for solid state fermentation. These results suggest that submerged fermentation period of inoculum have an effect on the production of monacolin K in red mold rice by solid state fermentation, and monacolin K in red mold rice could be increased by controlling the condition of submerged fermentation for inoculum.

• Applied Biological Chemistry
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• v.46 no.4
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• pp.367-375
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• 2003

The puree of Rubus coreanus was fermented using lactic acid bacteria and its biological activities were examined. Lactobacillus acidophilus KCCM 32820, L. casei KCCM 12452, Lactococcus lactis subsp. lactis KCCM 40104, and Streptococcus thermophilus KCCM 40430 were used as a single or mixed starter for the lactic acid fermentation, and their cultures at the late logarithmic growth phase were inoculated to final concentration of 2% (v/v). L. casei fermented the puree of Rubus coreanus best when used as a single starter, and the culture of L. casei and L. lactis with the inoculation ratio of one to one showed the highest fermentation activity when used as a mixed starter. However, the fermented broth of the puree of Rubus coreanus using L. acidophilus and S. thermophilus showed the best results in the sensory evaluation. The optimal lactic acid fermentation conditions were as follows; the concentration of oligosaccharide added was 1% (w/v), pH of puree and fermentation temperature were 4.0 and $37^{\circ}C$, respectively, and fermentation time was $72{\sim}96$ hours. Glucose and fructose were major free sugars, and the content of lactic acid was 698.2 mg/100 g in the fermented broth. The fermented broth of the puree of Rubus coreanus showed the electron donating ability and nitrite scavenging ability with the value of 69% and 38.3% at pH 1.2, respectively. SOD-like activity and inhibitory activity on xanthine oxidase were also found in the fermented broth with the value of 60.3% and 41.8%, respectively. When the antimicrobial activities of the fermented broth were examined, it showed the highest growth inhibitory activity against Escherichia coli O-157:H7, and also contained antimicrobial activities against Salmonella typhimurium, Bacillus cereus, and Staphylococcus aureus.