• Food Science of Animal Resources
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• v.40 no.4
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• pp.636-648
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• 2020

This study investigated the effects of the addition levels of white kimchi powder and acerola juice powder, as natural sources of sodium nitrite and sodium ascorbate, on the quality of cooked ground pork products. Freeze-dried white kimchi powder was prepared and used after fermentation for 2 wk. Six treatments were included: control (100 ppm sodium nitrite and 500 ppm sodium ascorbate), treatment 1 (0.2% white kimchi powder, 0.02 % starter culture, and 0.1% acerola juice powder), treatment 2 (0.2% white kimchi powder, 0.02% starter culture, and 0.2% acerola juice powder), treatment 3 (0.4% white kimchi powder, 0.04% starter culture, and 0.1% acerola juice powder), treatment 4 (0.4% white kimchi powder, 0.04% starter culture, and 0.2% acerola juice powder), and treatment 5 (0.4% celery powder, 0.04% starter culture, and 0.2% acerola juice powder). The pH values were decreased (p<0.05) because of lower pH of acerola juice powder, resulting in lower cooking yields (p<0.05) in these treatments. CIE L* and CIE a* values of indirectly cured meat products were not different (p>0.05) from the sodium nitrite-added control. However, indirectly cured meat products showed lower (p<0.05) residual nitrite contents, but higher (p<0.05) nitrosyl hemochrome contents and cure efficiency than the control. Treatments 2 and 4 had higher (p<0.05) total pigment contents and lipid oxidation than the control. This study indicates that white kimchi powder coupled with acerola juice powder has substantial potential to substitute synthetic nitrite to naturally cured meat products, which could be favored by consumers seeking clean label products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.156-159
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• 2001

The experiment was carried out to investigate the productivity of freshwater rotifer, Brachionus calyciflorus and marine rotifer, B. rotundiformis at various temperatures, initial inoculation and pH in a 5 L semi-continuous high density culture. Rotifers were fed by commercial condensed freshwater Chlorella. When pH was not controlled, average daily productions of freshwater and marine rotifers increased with temperature. The highest production, $44\times10^6$ rotifers, was achieved of B. calyciflorus at $32^{\circ}C$ and the possible production lasting period of B. calyciflorus was shorter than that of B. rotundiformis. Under the adjustment of pH at 7, the possible production lasting periods of B. calyciflorus and B. rotundiformis inoculated with 5,000 inds./mL were longer than those of rotifers inoculated with 10,000 inds./mL, and the daily production rate of the former was higher than that of the latter. The results from this study indicated that optimum density of the initial inoculation for the cultivation of B. calyciflorus and B. rotundiformis was 5,000 inds,/mL under the controlled conditions of pH 7 and at $32^{\circ}C$ in a semi-continuous high density culture, in terms of production rate and food cost aspects.

• Applied Chemistry for Engineering
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• v.20 no.3
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• pp.285-289
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• 2009

Recently, as the interest in the accelerated global warming and the food shortage problem is increased, the concerns for microalgae as photosynthetic microorganisms are also increased. Specially, photosynthetic microalgae, Spriulina platensis have been an attractive source for $CO_2$ gas fixations and for a vast array of valuable nutritious compounds. In this paper, to culture the microalgal Spirulina platensis NIES 39 in a batch culture with high mass, optimal conditions for the culture temperature, initial pH, light intensity and concentration of carbon and nitrogen, were tested. At the most favorable culture condition, $35^{\circ}C$, initial pH 9.5, 4500 lux and carbon and nitrogen concentration of 16.8 g/L $NaHCO_3$ and 2.5 g/L $NaNO_3$, the excellent yields of 2.10 g/L biomass and 29.53 mg/L chlorophyll were obtained.

• Journal of Life Science
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• v.22 no.6
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• pp.799-806
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• 2012

Approximately 80 species of bacteria were isolated from the fermented mushroom first and the HJ-57 antibacterial micro-organism was selected to the final isolation bacteria. It has a high degree of CMCase, amylase, and protease activity as well as high antibacterial activity against mushroom pathogenic bacteria without affecting the growth and development of Flammulina velutipes and Lentinus edodes mushrooms. The finally selected HJ-57 antibacterial micro-organism was identified as Bacillus sp. HJ-57. The initial pH for culture was pH7 and its optimum culture temperature was $35^{\circ}C$. The antibacterial material produced by Bacillus sp. HJ-57 showed a little antibacterial activity even in the 12 hr of culture, but showed the highest antibacterial activity in the 36~48 hr of culture. The HJ-57 antibacterial micro-organism also showed a high antibacterial activity against mushroom pathogenic bacteria and molds in the corn cob contained culture medium is used in Flammulina velutipes cultivators.

• Journal of Microbiology and Biotechnology
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• v.22 no.5
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• pp.659-667
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• 2012

2,3-Butanediol (2,3-BDO) is an organic compound with a wide range of industrial applications. Although Escherichia coli is often used for the production of organic compounds, the wild-type E. coli does not contain two essential genes in the 2,3-BDO biosynthesis pathway, and cannot ferment 2,3-BDO. Therefore, a 2,3-BDO biosynthesis mutant strain of Escherichia coli was constructed and cultured. To determine the optimum culture factors for 2,3-BDO production, experiments were conducted under different culture environments ranging from strongly acidic to neutral pH. The extracellular metabolite profiles were obtained using high-performance liquid chromatography (HPLC), and the intracellular metabolite profiles were analyzed by ultra-performance liquid chromatography and quadruple time-of-flight mass spectrometry (UPLC/Q-TOF-MS). Metabolic flux analysis (MFA) was used to integrate these profiles. The metabolite profiles showed that 2,3-BDO production favors an acidic environment (pH 5), whereas cell mass favors a neutral environment. Furthermore, when the pH of the culture fell below 5, both the cell growth and 2,3-BDO production were inhibited.

• Mycobiology
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• v.51 no.4
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• pp.230-238
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• 2023

Glabridin is a well-known active isoflavone found in the root of licorice (Glycyrrhiza glabra L.) that possess a wide range of biological activity. Plant cells, hairy roots, and fungal endophytes cultures are the most important alternative methods for plant resources conservation and sustainable production of natural compounds, which has received much attention in recent decades. In the present study, an efficient culture condition was optimized for the biomass accumulation and glabridin production from fungal endophyte Aspergillus eucalypticola SBU-11AE isolated from licorice root. Type of culture medium, range of pH, and licorice root extract (as an elicitor) were tested. The results showed that the highest and lowest biomass production was observed on PCB medium (6.43 ± 0.32 g/l) and peptone malt (5.85 + 0.11 g/l), respectively. The medium culture PCB was produced the highest level of glabridin (7.26 ± 0.44 mg/l), while the lowest level (4.47 ± 0.02 mg/l) was obtained from the medium peptone malt. The highest biomass (8.51 ± 0.43 g/l) and glabridin (8.30 ± 0.51 mg/l) production were observed from the PCB medium adjusted with pH = 6, while the lowest value of both traits was obtained from the same medium with pH = 7. The highest production of total glabridin (10.85 ± 0.84 mg/l) was also obtained from the culture medium treated with 100 mg/l of the plant root extract. This information can be interestingly used for the commercialization of glabridin production for further industrial applications.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.89-95
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• 1998

Rhodopseudomonas sphaeroides K7 and E15-1 produced hydrogen from glucose rapidly for the first 24 hrs of culture under the anaerobic and photosynthetic conditions and then ceased the hydrogen production because of the accumulation of organic acids such as acetic acid and formic acid in the culture broth, decreasing the pH to 4.2-4.5. Only 43% and 73% of glucose in the culture were consumed even after 6 days of incubation by R. sphaeroides K7 and E15-1, respectively. The hydrogen production and glucose consumption, however, were substantially increased when the pH of the culture was adjusted to 6.8-7.0: Hydrogen production continues even after 10 days of culture and glucose was consumed completely after 2.5 and 4.5 days by R. sphaeroides K7 and E15-1, respectively, Furthermore, the bacteriochlorophyll contents in R. sphaeroides K7 and E15-1 were increased by 44 and 9 folds and the cell concentrations by 10 and 2.5 folds, respectively, after 7 days of culture. R. sphaeroides K7 and E15-1 also produced hydrogen from acetic, lactic, butyric and malic acids under the anaerobic and photosynthetic conditions even though the amounts of hydrogen produced were lower than that from glucose. The results of this experiment indicate that under the anaerobic and synthetic conditions R. sphaeroides K7 and E15-1 might use the NADH oxidation mediated by ferredoxin and hydrogenase to evolve hydrogen from glucose for the first 24 hrs and then the organic acids produced were used as electron donners for the production of hydrogen in the nitrogen-limited condition.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.333-338
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• 1987

In order to establish the biological treatment system which can be used for treatment of waste aster from acetaldehyde plant, it was investigated optimum nutrient requirements and growth conditions by mixed culture of Micrococcus roseus AW-6, Micrococcus luteus AW-22, Microbacterium lacticum AW-38 and Microbacterium laevaniformans AW-41 as well as the effect of coagulants and neutralization reagents. Also, it was carried out the continuous culture as well as batch culture to treat the waste water by mixed culture of these strains. The COD removal rate was reached to maximum state for 96hrs culture at pH7.0 and $30^{\circ}C$ NaOH as the neutralization reagents was the most effective, but the coagulants had no effect on the COD remonal rate and the optimum dilution times for treatment were 10 fold. The COD removal rate was also increased by supplimenting 200 ppm $NH_{2}NO_{3}$, 50 ppm $KH_{2}PO_{4}$, 15 ppm $CaCl_{2}$ and 1 ppm $MgSO_{4} \cdot 7H_{2}O $ as additional nutrients. The removal rate coefficient $K_{1}$ on the batch culture was $4.5\times 10^{-6}$, and the detention time for BOD removal rate of 85% was approximately 45hrs. The COD of waste water was reduced to 15% of its initial value by the continuous culture. The COD and BOD of the effluents were to be about 60 ppm and 40 ppm, respectively, and final pH was 7.0.

• Journal of Life Science
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• v.11 no.5
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• pp.496-501
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• 2001

This study was carried out to investigate the cultural characteristics and the genetic characteristics in Lepists nuda. The mycelia cultural characteristics which include the specificity for pH, carbon source, nitrogen source and medium were studied using petridish culture and liquid media culture respectively. The genetic characteristics were also investigated using random amplified polymorphic DNA (RAPD) analysis. To find out the mycelial growth rate by various medium, mycelia was cultured for 25 days in PDA, YM, MEA, GPB and Yamanaka. The Yamanaka was superior to the other media in supporting the mycelial growth. pH6 produced the best result in the test of an optimal pH. In experiment for optimal carbon source, starch showa 46.8$\pm$1.7mm of diameter of mycelial colony as the best and for nitrogen source, yeast extract showed a good effect as well. In investigation for genetic characteristics, Lepists nuda was amplified by 7 primers among 10 primers and Pleurotus ostreatus was also amplified by 7 primers. From the RAPD analysis between species, the band patterns were different.

• Journal of the Korean Society of Food Culture
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• v.25 no.6
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• pp.788-794
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• 2010

Camellia sinensis L. (green tea) seed oils were prepared by roasting at $213^{\circ}C$ and pressing (RP), pressing (P), and nhexane extraction (H). The physico-chemical properties of the RP, P, and H samples, including fatty acid composition, color, and sensory characteristics were analyzed. RP, P and H samples were thermally oxidized at $180^{\circ}C$, and oxidative stability was determined by DPPH, CDA, and p-AV at 0, 20, 40, 60, and 80 min. Compared to the P and H samples, RP resulted in significantly higher thermal oxidative stability according to the DPPH, CDA, and p-AV results (p<0.05). The ratio of unsaturated fatty acids to saturated fatty acids among RP, P, and H samples were significantly different (p<0.05). The oleic acid and linoleic acid contents in green tea seed oils were 58 and 23%, respectively. Hunter's color value of lightness (L) for the RP, P, and H samples was not significant. Redness (a) of RP was $3.47{\pm}0.119$ and yellowness (b) of H was $60.10{\pm}2.483$, which were significantly different. Compared to RP samples, H and P samples had the highest color and off-odor values in the sensory evaluation. RP samples showed the highest taste value and were significant overall (p<0.05). The thermal stability of RP extraction was more stable than any other method. Camellia sinensis L. seed oil extracted by RP had better sensory characteristics than other edible oils, including soybean oil, grape seed oil, and extra virgin olive oil.