• Journal of Life Science
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• v.7 no.1
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• pp.30-38
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• 1997

For screening thermostable $\alpha$-amylase from thermophiles, various samples from extreme environments such as hot spring and sewage near them, and compoat, wereexamined microbial growth in enrichment culture medium at 55$\circ$C on the assumption that enzymes from thermophiles are inevitable thermostable. One strain showing higher $\alpha$-amylase activity was pure cultured and designated as Bacillus sp. TR-25 from the results of morphological, cultural and physiological characteristics. The most important carbon sourses for the enzyme production were soluble starch, dextrin, potato starch and corn starch. Glucose and fructose had a catabolite repression on the enzyme production. The good nitrogen sources for the enzyme production were yeat extract, nutrient broth, tryptone, corn steep liquor and ammonium sulfate. The enzyme production was accelerated by addition of CaCl$_{2}$. $\cdot $ H$_{2}$O. The optimal medium composition for the enzyme production was soluble starch 2.0%, yeast extract 0.55, CaCl$_{2}$ $\cdot $ 2H$_{2}$O 0.015, Tween 80 0.001%, pH8.0, respectively. In jar fermenter culture, this strain shows a rapid growth and required cheaper carbon and nitrogen source. These properties are very useful to fermentation industry. The $\alpha$-amylase of this strain demonstrated a maximum activity at 80$\circ$C, pH 5.0, respectively. And calcium ion did not improve thermostability of the enzyme. At 10$0^{\circ}C$, this enzyme has 235 of relative activity. Transformation was carried out by thermophilic Bacillus sp. TR-25 genomic DNA. As a result, the transformant has increased thermostable $\alpha$-amylase activity.

• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.728-736
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• 2015

Cronobacter species (Cronobacter spp.), previously known as Enterobacter sakazakii, are gram negative food borne pathogenic bacteria. They pose a very high risk of infection to neonates and immuno-compromised individuals and can affect the human central nervous system. Consequently, survivors often suffer from severe neurological impairment including hydrocephalus, quadriplegia, and developmental delays. Cronobacter spp. were not only isolated from plant food and products such as cereals, fruits, vegetables, legume products, herbs, and spices but also from animal source foods such as milk, meat, fish, and products made from these foods. Therefore, rapid detection of Cronobacter spp. is essential for food safety. Many detection methods have been developed since the Cronobacter spp. were first reported. However, the development of more rapid, sensitive, and easy-to-use detection methods for the Cronobacter spp. is required. In this review, our aim was to study and compare the available detection methods for Cronobacter spp., including culture-based, molecular biology-based, and immunology-based methods. This study will contribute to the development of new and rapid detection method for Cronobacter spp.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.626-636
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• 2003

Pediococcus pentosaceus K1270 was isolated from naturally fermented kimchi and identified based on the 16S rDNA sequence as well as cultural and biochemical characteristics. This strain strongly inhibited the formation of biofilm by Streptococcus mutans Ingbritt. K1270 also showed antibacterial activity against S. mutans Ingbritt. It was observed that K1270 strain produced hydrogen peroxide on MRS agar supplemented with 3, 3, 5, 5-tetramethylbenzidine (TMB) and peroxidase and the inhibitory effect of K1270 strain on the biofilm formation was reversed by the addition of catalase in part. Culture supernatant of K1270 inhibited the biofilm formation and the multiplication of S. mutans Ingbritt. This inhibitory effect of culture supernatant was decreased slightly by the addition of catalase and abolished by heat or trypsin treatment. Thus, this study suggests that P. pentosaceus K1270 inhibit the biofilm formation through the inhibition of the replication of S. mutans Ingbritt by producing hydrogen peroxide and bacteriocin.

• Journal of dental hygiene science
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• v.4 no.3
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• pp.127-131
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• 2004

This study was to study the antibacterial effect of Lignum sappan extract on S. mutans growth. The antibacterial activities of Lignum sappan's crude extract was measured 17.3 mm at 20 mg/ml concentration. The growth of S. mutans in control medium was the highest at 8hr, while the media of Lignum sappan extract added-medium (2 mg/ml) showed maximum growth at 16hr. The pH values of the control media was 5.08 at 8hr, but the media supplemented with Lignum sappan extract was 6.69 at 8hr. The amounts of total carbohydrate of the control media was 0.81 mg/ml at 8hr, but the media supplemented with Lignum sappan extract was 2.06 mg/ml at 8hr. In the protein change of culture medium, the control culture broth and the cultures supplemented with Lignum sappan extract was 8.39 mg/ml and 12.3 mg/ml at 8hr, respectively. The S. mutans polysaccharide contents of the control media and the media supplemented with Lignum sappan extract was 300 mg/100ml and 60 mg/100ml at 8hr, respectively.

• Journal of Life Science
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• v.17 no.10
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• pp.1434-1440
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• 2007

We have investigated the effects of mushroom mycelium (Phellinus linteus, Coriolus versicolor) mixed cultural extract on the immune responses of olive flounder, Paralichthys olivaceus. The mixed culture extracts were evaluated for the growth, hematology, lysozyme activity, leukocyte phagocytic activity, and disease resistance against Vibrio anguillarum. In the effect of the growth, the body weight and length gain in the group, which fed with mushroom mycelium mixed cultural extract, were 52 g and 3.4 cm higher than that in the control, respectively. For the hematology, the administration of mushroom mycelium mixed cultural extract resulted in increase of glucose. However, there was no distinct differences in GOT (glutamic oxaloacetic transaminase), GPT (glutamlc pyruvic transamlnase), TG, TP, and LDH (lactate dehydronase) among each group. The activities of lysozyme were 80% higher in the experimental groups than in the control. The activities of leucocyte were 66% higher in the experimental groups than in the control. Although lysozyme activity and leucocyte activity showed somewhat decrease after 12 weeks, these activities were still higher than in the control. The cumulative mortality (%) after an artificial challenge with $7{\times}10^8\;CFU$ of Vibrio anguillarum per fish was 25% higher in the experimental groups than the control.

• Korean Journal of Microbiology
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• v.42 no.3
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• pp.172-176
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• 2006

In order to increase the productivity of lipstatin by Steptomyces toxytricini, the effect of medium components on the lipstatin production was investigated. Using TSB medium as a basal medium, a variety of carbon sources, nitrogen sources, lipid and fatty acids was supplemented into a fermentation medium. The seed culture of S. toxytricini grown in 25 ml TSB medium at $28^{\circ}C$ for 3 days with agitation at 200 rpm was inoculated in the size of 2% in fermentation media containing different components and fermented at $28^{\circ}C$ for 60 more hrs. In the examination of the effect of carbon sources, the best cell growth was observed in fermentation media supplemented with glucose or glycerol, but the lipstatin productivity was the highest in media containing lactose or sucrose. Among complex nitrogen sources, yeast extract was the best one for cell growth, but the highest lipstatin production was found in TSB media composed of 1.7% casitone and 0.3% soytone. The increased concentration of triolein as a lipid caused the promotion of cell growth but the significant suppression of lipstatin production. When 0.5% fatty acids were supplemented to fermentation medium, unsaturated fatty acids like linoleic or oleic acid suppressed cell growth as well as lipstatin production, but 2 times higher lipstatin production was achieved by stearic acid, a saturated fatty acid, differently from expectation.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.389-394
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• 2003

In order to screen microorganisms producing phopholipase D (PLD) had high transphosphatidylation activity, about 1,000 Actinomycetes strains were isolated from the 63 soil samples, collected over 6 local area in Korea. When the hydrolytic activity in the supernatant was determined, 131 strains produced PLD more than 0.3 U/ml. Among 131 culture broths tested, 23 ones had transphosphatidylation activity higher than 20% and finally one strain (Actinomycetes KF 923), which had highest hydrolytic and transphophadylation activity, was selected. Actinomycetes KF923 showed the highest hydrolytic activity (13 U/ml) and phosphatidylation activity (95%) after 48 h fermentation using the P medium (yeast extract 1%, peptone 1%, glucose 1.5%, glycerol 1%, $CaCo_3$ 0.4%, pH 7.2). PLD was purified from the culture broth of Actinomycetes KF923 and the specific activity of purified PLD was 567 U/mg. The molecular weight of PLD was about 55 kD and the optimum pH and temperature were 6.0 and $60^{\circ}C$, respectively. The stability of PLD toward pH and temperature were high around pH 8.0 and below $40^{\circ}C$. Special metal ions were not necessary to the PLD activity.

• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.17-23
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• 2002

In order to investigate effects if loess on the mycellial pellet formation a phosphate-solubilizing fungus. Aspergillus sp. PS-104 was cultured in potato dextrose broth containing loess. The strain formed an amorphous pellet or loose aggregates agitated at a low speed (50 rpm) while spherical and regular pellets at a high speed (150 rpm) The higher concentration of loess was added, the smaller size of a pellet was formed during the submerged culture of the strain. As shown in results, being cultured in the PDB medium supplemented with 1.0% loess the pellet size was maximally reduced to a fourth compared to the control. Evaluating the addition effect of several components of loess such as $SiO_2$, $Fe_2O_3$, $Al_2O_3$, $CaCO_3$, $CaSO_4$ and $MgCO_3$ on the reduction of mycellial pellet size the higher concentration was supplied, the smaller size of pellet was formed except $Al_2O_3$. And the smallest pellet size was recorded at the concentration of 1.0% (W/V) magnesium carbonate.

• Applied Biological Chemistry
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• v.41 no.7
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• pp.489-495
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• 1998

The optimum culture condition of Scopulariopsis brevicaulis for the production of ${\alpha}$-galactosidase was as follows: Tryptone 1.5%, $NH_4NO_3$ 0.2%, Raffinose 2.5%, $KH_2PO_4$ 0.5%, yeast extract 0.5%, pH 7.0, $27^{\circ}C$. The optimum pH and temperature for the enzyme activity of ${\alpha}$-galactosidase producing Scopulariopsis brevicaulis were pH 7.0 and $27^{\circ}C$, respectively. The enzyme was relatively stable at $pH\;6.0{\sim}8.0$ and at temperature below $40^{\circ}C$. The activity of the enzyme was inhibited by $Ag^{2+},\;Hg^{2+},\;Cu^{2+}$, p-chloromercuribenzoic acid and Iodine. These results would indicate the presence of -SH groups in the catalytic site of the enzyme. Km value was 1.9 mM for $p-nitrophenyl-{\alpha}-D-galactopyranoside$ and Vmax value was $9.66{\times}10^2\;{\mu}M/min$. Sugar constituents of culture broth were identified by HPLC that the enzyme liberated sucrose, glucose and fructose from raffinose and raffinose was significantly decreased.

• Journal of the Korean Society of Food Culture
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• v.23 no.2
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• pp.273-292
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• 2008

Among all the ingredients usedin mandu, the following types were used:, 13 types of grains were used (12.38%), 30 types of vegetables, fruits, bulbs,and nuts were used (28.57%), 32 types of marine products, birds, meats, fishes, and shellfishes were used (30.48%), 10 types of functional ingredients were used (9.52%) and. For spices, 20 types of spices were used (19.05%). 2. Cooking Methods offor Mandu. The mMandu eaten at in the early Joseon era had was primarily made ofusedbuckwheat that contained boiled tofu or egg uiijuk in the kneaded dough for the most part and while kneading with buckwheat, the tofu or egg uiijuk has been boiled down to knead the dough, and and starch powder, bean powder, or rice powder, etc were mixed to make the mandu coating. Buckwheat powder was mixed toadded to the flourwer or was used by itself, while meat, vegetables, tofu, and shiitake mushroom, etc were also addedincluded. From the 18th century, the host plant, or cabbage kimchi, were prepared and combined had been sliced to be used as filling together while red pepper powder was mixed combined withto spices or vinegar soy sauce to be used together. Also, Radishes had beenwere also used as filling, but shown as not being used fromafter the start of the 1900's. For the shape of mMandu, it was madeinto different shapes such as as triangle, rectangle, date plum, gwebul, half moon, or pomegranate shapes, and then shapes to be boiled in simmering water, baked, or cooked as soup in clear broth for soup., In the 17th to 18th century, boilingthen in a steamer gradually became a cooking style, assumed the style of boiling in a steamer in $17th{\sim}18th$ century while in the 16th century,the an essay ofn fermenting flour in ‘Food Dimibang’ in 16th century had indicated it was cooked as the style ofby steaming in a rice steamer. Also, Mandu may have also contained the following: the thin-cut and boiled fish was cut out thin to put into the filling and boiled down, made by putting in added pine nuts after making bbeef jerky or boiled- down meat, fish, or shellfish itself to extractsand mold mandu only the ingredients combined withto put on starch powder, and then boiled down and put on pine nut powder finally, after it or cooled it wasdown to be eaten by dipping in vinegar soy sauce. In conclusion, many different types of mandu were made during the Joseon era using a variety ofwhile the ones using such various ingredients. are also one type of mandu.