• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1834-1845
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• 2018

The lactobacilli associated with a fermented goat milk product from Tajikistan were isolated to characterize their technological properties and antibiotic resistances in order to assess their suitability for development as starter cultures. In this study, twenty three strains were identified by 16S rRNA sequencing as typical dairy-associated lactic acid bacterial strains, i.e. L. plantarum, L. pentosus, L. delbrueckii, L. helveticus and L. paracasei. These strains were generally susceptible to most antibiotics tested in this study and this allowed a selection of strains as safe starters. The draft genomes of four representative strains were sequenced and the number of contigs of the four assembled genomes ranged from 51 to 245 and the genome sizes ranged from 1.75 to 3.24 Mbp. These representative strains showed differences in their growth behavior and pH-reducing abilities in in vitro studies. The co-inoculation of these Lactobacillus spp. strains together with a yeast Kluyveromyces marxianus MBT-5698, or together with the yeast and an additional Streptococcus thermophilus MBT-2, led to a pH reduction to 3.4 after 48 h. Only in the case of fermentation inoculated with the co-culture, the viscosity of the milk increased noticeably. In contrast, fermentations with single strains did not lead to gelation of the milk or to a decrease in the pH after 24h. The results of this study provide a comprehensive understanding of the predominant lactobacilli related to Tajikistani fermented milk products.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.124-131
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• 2005

The regulation of gene expression plays an important rolet in cell cycle controls. In this study, a novel $mas3^+$ (mitosis associated protein) gene, a homolog of human SMARCADl, was isolated and characterized from a fission yeast Schizosaccharomyces pombe. The overall homology between the helicase proteins of the two species is $87\%$. This DEAD/H box-containing molecule has seven highly conserved sequence regions that allow us to place it in the SNF2 family of the helicase superfamily. Knock-out cell of $mas3^+$ gene was constructed using kanMX6 as a selection marker. Survival of mas3 null mutant exposed to UV or MMS was similar to those of wild type cells. $mas3^+$ expression was lowest at $G_2$ and gradually increased. Cytokinesis of mas3 null mutant was abnormal at $26^{\circ}C\;and\;35^{\circ}C$ and a large number of multi-septate cells were produced. These results indicate that the $mas3^+$ is involved in cytokinesis and cell shape control.

• The Korean Journal of Mycology
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• v.23 no.2 s.73
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• pp.129-138
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• 1995

DNA fragment being able to restore in vitro activity of ${\beta}-1,3-glucan$ synthase was cloned by transformation of the Saccharomyces cerevisiae LP353 mutant strain with genomic library constructed in the YCp50. For the selection of transformants which showed no detectable phenotype linked to recovery of the defect in ${\beta}-1,3-glucan$ synthase activity, the colony autoradiography was succesfully applied. The restriction map of the cloned DNA fragment, which is 8.5-kb in length, was constructed. Both the YEplac195 and the YCp50 carrying the 8.5-kb fragment increased ${\beta}-1,3-glucan$ synthase activity of LP353 by two fold. Neither the YEplac195 nor the YCp50 carrying the 8.5-kb DNA fragment, however, complemented the temperature-dependent osmotic sensitivity which is another distinctive phenotype of LP353. Subcloning experiments indicated that a functional region was located in 4.8-kb BglII-KpnI fragment. The 4.8-kb fragment was also able to increase the level of ${\beta}-1,3-glucan$ content in cell wall as well as the resistance of cells to cell wall lytic enzyme, ${\beta}-1,3-glucanase$. The growth rate of the LP353 with 4.8-kb fragment was almost same as that of wild type strain in liquid medium with 1.2 M sorbitol at nonpermissive temperature. Taken these results together, the 4.8-kb fragment seemed to contain the BGS2 gene for ${\beta}-1,3-glucan$ synthase activity in yeast S. cerevisiae.

• Research in Plant Disease
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• v.11 no.2
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• pp.158-161
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• 2005

Stenotrophomonas maltophilia BW-13 is a potent biocontrol agent to control crisphead lettuce bottom rot caused by Rhizoctonia solani. To define the optimum conditions for the mass production of the S. maltophilia BW-13, we have investigated optimum culture conditions and effects of various carbon sources on the bacterial growth. The optimum initial pH and temperature were determined as pH $6.0\~7.0 and $35^{\circ}C$, respectively. For the selection of effective carbon source for the mass production, we tested the low molecular carbon sources such as sucrose, glucose, lactose, maltose, manose and the high molecular carbon source such as dough conditioner, rice bran, corn starch, sweet potato starch. As the results, the addition of dough conditioner in a basal medium ($1.25\%\;K_{2}HPO_4,\;0.38\%\;KH_{2}PO_4,\;0.01\%\;MgSO_4{\cdot}7H_{2}O,\;0.5\%\;Yeast extract$) was able to achieve higher cell density and the antifungal activity than others. Therefore, the basal medium containing $3\%$ dough conditioner (named as dough conditioner medium) was finally selected the optimized media for the mass production of BW-13 strain.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.203-211
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• 2000

In this study to produce large-scale scopolamine we were examined in the tumor calli of Datura metel L. induced by Agrobacterium tumefaciens $Ery{101}$. The growth and scopolamine contents of tumor calli were higher under light condition than in dark. The optimum condition of growth and scopolamine production were fluence rate of 16 $\mu$mol $m^{-2}s^{-1}$, spectra of red light region and 16 hour light periods on 50 mL SH liquid medium in 4 weeks culture. To increase of the scopolamine contents in tumor calli, the optimum concentration of nitrogen source were 1.8 mM NH$_4$+ and 40 mM NO$_3$. The optimum elicitor concentration for production of scopolamine were 10 mg/L chitosan and 15 mg/L yeast extract. The effect of precursors were good at the concentration of 0.2 mM tropine and 0.3 mM tropic acid, respectively. In order to increase of growth and scopolamine contents. we induced mutant from Datura metel L. tumor callus. Mutants of tumor calli were obtained by 3 Krad, 4 Krad and 6 Krad of ${60}^Cor-ray$. Among them, 3 Krad tumor callus was excellent on the growth and teratoma induction. The 4 Krad tumor callus was negligible for both growth and teratoma induction. But the 6 Krad tumor callus was the best in growth and teratoma induction. The formation of the mutant calli can be enhanced through hormonal combination of 1 mg/L 2,4-dichlorophenoxyacetic acid and 0.5 mg/L benzyladenine. We carry out selection mutant tumor calli for high content tropane alkaloid and suspension cultures for scopolamine production.

• Applied Biological Chemistry
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• v.18 no.4
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• pp.219-227
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• 1975

In order to investigate the possibility of wine-making with the grape variety cultivating in Korea, the basic analysises were carried out; analysis of the grape maturity during ripening period, the composition of grape juice, and the chemical components of wine from different varieties. Also the yeasts existing naturally on the grape were isolated and identified. For the selection of strain, the characteristics of 6 strains were studied. The results obtained were summarized as follows. 1. The reducing sugar content increased considerably during two weeks after the ordinary grape-gathering period. 2. The sugar content was highest in Muscat bailey A, which could be fermented naturally. The other varieties, Campbell Early, Steuben, and Alden needed chaptalisation for wine-making. 3. The permanaganate number and the methanol content of wine from all varieties were lower than french wine. 4. The sensory evaluation of wine showed that the pink wine was appreciated better than the red wine of same variety and the foxy taste of wine from hybrid grape influenced little to Korean. 5. The selected 6 strains were identified as Saccharomyces chevaliers, Saccharomyces capensis and Saccharomyces globosus. The strain No. 3 and No. 4 showed the most excellent characters for wine-making.

• The Korean Journal of Mycology
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• v.42 no.4
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• pp.328-332
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• 2014

For mass production of entomopathogenic fungus Beauveria bassiana 149, isolated from moth larva, by two-phase fermentation, we performed selection of carbon and nitrogen sources for liquid culture and examined solid fermentation on carrier, ingredient, temperature, and water content. Spore production with rice powder, corn powder, and starch from sweet potato was higher than that of sucrose and dissolvable starch for liquid fermentation as first-phase fermentation. As a nitrogen source, addition of peptone and yeast powder showed higher spore production than $NaNO_3$, fish powder, and soybean powder. The isolate produced more conidia in sawdust + wheat bran + corn powder, sawdust + wheat bran and rice shell + wheat bran as carrier and ingredient than vermiculite as carrier. Conidia production of B. bassiana 149 in solid-phase fermentation was twice higher at 30 than 20. Conidia yield was higher at 60% and 70% water content ($26.9{\times}10^8$ and $38.6{\times}10^8conidia/g$) than 40% and 50% ($13.9{times}10^8 $and $11.6{\times}10^8conidia/g$), respectively.

• KSBB Journal
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• v.17 no.3
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• pp.290-294
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• 2002

The present work describes the improvement of an erythritol-producing strain to lower the formation of glycerol, which is a characteristic by-product of the strain and could cause difficulties in the recovery and purification of the final product. The yeast-like fungi Moniliella suaveolens var. nigra, isolated previously in the same laboratory from beehives, was mutated by exposing it to a 4 g/L NTG solution. From a total of 2000 mutated strains, Em6j30-14 was selected as the one having the most desirable properties. Cultivating the strain for seven days in 300 mL flasks containing 30 mL of a 400 g/L glucose medium resulted in an erythritol yield of 43%. The glycerol yield was 5%, which is a value 50% lower as compared with the wild type. However, attempts to reproduce the above results in a 5L-fermenter failed, resulting in a similar erythritol concentration but a much higher formation of glycerol. Possible reasons for such a different behaviour could be oxygen limitation or the aggregation of cells, but the exact mechanism could not yet be identified. Foam formation, which is another major problem in large-scale fermentation, tended to be much lower for the mutant strain.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.697-706
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• 2018

Lactobacillus pentosus K1-23 was selected from among 25 lactic acid bacterial strains owing to its high inhibitory activity against several pathogenic bacteria, including Escherichia coli, Salmonella typhimurium, S. gallinarum, Staphylococcus aureus, Pseudomonas aeruginosa, Clostridium perfringens, and Listeria monocytogenes. Additionally, among 13 strains of Aureobasidium spp., A. pullulans NRRL 58012 was shown to produce the highest amount of ${\beta}$-glucan ($15.45{\pm}0.07%$) and was selected. Next, the optimal conditions for a solid-phase mixed culture with these two different microorganisms (one bacterium and one yeast) were determined. The optimal inoculum sizes for L. pentosus and A. pullulans were 1% and 5%, respectively. The appropriate inoculation time for L. pentosus K1-23 was 3 days after the inoculation of A. pullulans to initiate fermentation. The addition of 0.5% corn steep powder and 0.1% $FeSO_4$ to the basal medium resulted in the increased production of lactic acid bacterial cells and ${\beta}$-glucan. The following optimal conditions for solid-phase mixed culture were also statistically determined by using the response surface method: $37.84^{\circ}C$, pH 5.25, moisture content of 60.82%, and culture time of 6.08 days for L. pentosus; and $24.11^{\circ}C$, pH 5.65, moisture content of 60.08%, and culture time of 5.71 days for A. pullulans. Using the predicted optimal conditions, the experimental production values of L. pentosus cells and ${\beta}$-glucan were $3.15{\pm}0.10{\times}10^8CFU/g$ and $13.41{\pm}0.04%$, respectively. This mixed culture may function as a highly efficient antibiotic substitute based on the combined action of its anti-pathogenic bacterial and immune-enhancing activities.

• Korean Journal of Medicinal Crop Science
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• v.11 no.5
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• pp.358-363
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• 2003

ScopoIamine and hyoscyamine which belong to tropane alkaloids are the pharmaceutically valuable anticholinergic drugs. In order to increase the productivities, the effects of elicitation were investigated during hairy root cultures of Scopolia. parviflora. Biotic elicitors originated from 3 fungi and 1 yeast were prepared as homogenate and supernatant and added to 3-week-old cultures. Both of homogenate and supernatant of Candida albicans elicitors increased the scopolamine production. The production of hyoscyamine was enhanced by homogenate of Fusarium solani and supernatant of C. albicans. Most of the other fungal elicitors were also improved on the tropane alkaloid production compared to non-treatment. Among the elicitors tested, C. albicans was proved the optimal biotic elicitor on tropane alkaloids production. These results will be served mass production of tropane alkaloids by large-scale production.