• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.17 no.3
• /
• pp.184-190
• /
• 1984

Sardine, Sardinops melanosticta, has been caught more than fifty thousand metric tons every year in adjacent sea of Korea, but most of them used for uneatable fish meal because of their rapid spoilage. Usually it is known that the main reason of putrefaction of foods is caused by the maicro-organisms included in them. Therefore, this experiment was carried out to identify the micro-organisms isolated from the intestine of fresh sardine and characterize their proteolytic enzymes produced from them. Aerobic cell count ranged from $1.7{\times}10^4\;to\;3.6{\times}10^5/g$, while anaerobic cell count, from $2.9{\times}10^4\;to\;5.5{\times}10^5/g$. Most of the isolated strains were psychrotrophic mesophiles. Among the two hundred and eighty strains isolated from the fresh samples, fifty-six strains ($20.0\%$) were proteolytics, one hundred and seventy-five strains ($62.5\%$) were lipolytics and tenty-nine strains ($10.5\%$) had the ability to produce hydrogn sulfide. The most predominantly isolated microbial groups from the fresh sardine were Moraxella ($31.4\%$) and Pseudomonas sup. ($28.6\%$). Flavobacterium-Cytophaga, Vibrio, Acinetobacter, Micrococcus spp. and Enterobacteriaceae appeared from $7.9\%\;to\;5\%$ out of total tested strains. The average bacterial count in the spoiled samples (stored at about $18^{\circ}C$ for 48 hours) was increased to the level of $2.9{\times}10^8/g$ for aerobes, $1.5{\times}10^8/g$ for anaerobes, then one hundred and ten strains, corresponding to $52\%$, out of two hundred and thirteen strains submitted to the test were proteolytics. The strongest proteolytic bacterium among the two hundred and eighty strains was identified as Pseudomonas 101 which grew best at $25^{\circ}C$. The optimum condition for the activity of the proteolytic enzyme produced by Pseudomonas 101 appeared $35^{\circ}C$ and pH 9.0, but the activity was relatively unchanged between 5.0 and 11.0 of pH and between $30^{\circ}C\;and\;50^{\circ}C$ of temperature.

• Korean Journal of Microbiology
• /
• v.52 no.4
• /
• pp.463-470
• /
• 2016

The enzymatic degradation of xylans is the most versatile way to obtain the high value-added functional compounds or the fermentable sugars for renewable energy. The endo-${\beta}$-xylanases are the major enzymes which hydrolyze the internal ${\beta}$-1,4-linkages of xylan backbones to produce the mixtures of xylooligosaccharides including xylobiose and xylotriose. Among them, glucuronoxylanase GH30 can exclusively hydrolyze the internal ${\beta}$-1,4-linkages of xylans decorated with methylglucuronic acid branches. In the present study, two xylanolytic enzyme (PaXN_10 and PaGuXN_30) genes were cloned from Paenibacillus amylolyticus KCTC 3005, and expressed in Escherichia coli, respectively. PaXN_10 (38.7 kDa) belongs to the endo-${\beta}$-xylanases GH10 family, while PaGuXN_30 (58.5 kDa) is a member of glucuronoxylanase GH30. They share the same optimal reaction conditions at $50^{\circ}C$ and pH 7.0. Enzymatic characterization proposed that P. amylolyticus can utilize the hardwood glucuronoarabinoxylans via the cooperative actions of xylanases GH10 and GH30. The extracellular PaGuXN_30 is secreted into the medium and hydrolyzes glucuronoarabinoxylans to release a series of aldouronic acid mixtures with a methylglucuronic acid branch. The resultant products being transported into the microbial cell are successively degraded into the smaller xylooligosaccharides by the intracellular PaXN_10, which will be utilized for the cellular metabolism.

• The Korean Journal of Food And Nutrition
• /
• v.30 no.1
• /
• pp.59-66
• /
• 2017

This study investigated the quality characteristics and biological activities of rice germ fermented by Bacillus spp. During the milling process, the contents of rice germ in the rice bran (Control) were adjusted to 30% (RG30) and 70% (RG70). The approximate composition, pH, total acidity, total soluble solid, total sugar, polyphenol and flavonoid contents were measured. DPPH radical scavenging activity, xanthine oxidase (XO) and angiotensin converting enzyme (ACE) activities were also determined. We observed that the moisture content decreased after fermentation, while the crude protein was significantly increased. Fermentation remarkably lowered the pH from 5.83~6.26 to 4.77~4.93, thereby elevating the total acidity. Fermentation also increased the total solid contents, from $0.40{\sim}0.87^{\circ}Bx$ to $1.63{\sim}2.20^{\circ}Bx$. The total sugar decreased to 136.81~151.53 mg/mL from 377.56~450.64 mg/mL. Polyphenol contents were the highest in control (0.59 and 0.73 mg/mL before and after fermentation, respectively). Fermentation significantly affected the increase of the polyphenols in both rice germ 30% and 70% samples, from 0.26 and 0.28 mg GAE/g before fermentation, to 0.52 and 0.70 mg GAE/g after fermentation, respectively. There was a slight increase in the flavonoid contents after fermentation. The $IC_{50}$ value of the electron donating ability, as evaluated by the DPPH method, was the lowest in control (3.77 and 3.36 mg/mL before and after fermentation, respectively). Fermentation increased the XO inhibition activity up to 63.69% in control, 49.81% in rice germ 30%, and 59.32% in rice germ 70%. The ACE inhibition activities were also increased in the fermented control, rice germ 30% and 70%, to 40.51%, 22.69% and 33.91%, respectively.

• Restorative Dentistry and Endodontics
• /
• v.27 no.5
• /
• pp.463-472
• /
• 2002

Bacterial lipopolysaccharide (LPS) plays a major role in stimulating the synthesis and release of the principal osteoclast-activating cytokines, namely, interleukin 1 and tumor necrosis factor-$\alpha$ from immune cells. Although rnonocytes/macrophages are the main producers of these cytokines, recent evidence has indicated that polymorphonuclear leukocytes (PMN) have the ability to release IL-1 and TNF-$\alpha$. Calcium hydroxide has been shown to be an effective medicament in root canal infections, reducing the microbial titre within the canal. It has been proposed that the therapeutic effect of Ca(OH)$_2$ may also be the result of direct inactivation of LPS. The purpose of this study was to investigate whether treatment of Porphyromonas endodontalis LPS with calcium hydroxide alters its biological action as measured by human PMN secretion of IL-1 and TNF-$\alpha$, and it was compared with Escherichia coli LPS. P. endodontalis ATCC 35406 was cultured in anaerobic condition, and LPS was extracted using the hot-phenol water extraction method and purified. Purchased E. coli LPS was also purified. 100 $\mu\textrm{g}$/ml of each LPS in pyrogen free water were incubated with 25mg/ml Ca(OH)$_2$ at 37$^{\circ}C$ for 7 days. The supernatants were subjected to ultrafiltration, and the isolates were lyophilized and weighed. PMNs were obtained from peripheral blood by centrifugation layered over Lymphoprep. The cells were resuspended (4$\times$10$^6$ cells/ml) in RPMI 1640 followed by treatment with various concentrations of LPS (0, 0.1, 1, 10$\mu\textrm{g}$/ml) for 24 hours at 37$^{\circ}C$ in 5% $CO_2$ incubator. The supernatants of cells were collected and the levels of IL-1$\alpha$, IL=1$\beta$ and TNF-$\alpha$ were measured by enzyme-linked immunosorbent assay. The results were as follows ; 1. The levels of IL-1$\alpha$, IL-1$\beta$, TNF-$\alpha$ from PMN treated with each LPS were significantly higher than those released from unstimulated PMN of the control group (p<0.05). 2. The levels of all three cytokines released from PMN stimulated with each calcium hydroxide treated LPS were significantly lower than those released from PMN stimulated with each untreated LPS (p<0.05), while they were not significantly different from those released from unstimulated PMN of the control group (p>0.05) 3. The levels of secretion for all three cytokines were affected in a dose-dependent manner in PMN stimulated with each LPS (p<0.05), but not in PMN stimulated with each calcium hydroxide treated LPS (p>0.05). 4. The levels of all three cytokines released from PMN stimulated with p. endodontalis LPS were significantly lower than those released from PMN stimulated with E coli LPS (p<0.05).

• Applied Biological Chemistry
• /
• v.13 no.1
• /
• pp.1-27
• /
• 1970

The process of the forced aging of flue-cured tobacco leaves were studied extensively from various scientific points of view. The Flue-cured tobacco leaves were inoculated and fermented with nicotine resistant Hansenula yeast, or the leaves were subjected under simple forced aging. The above two processes of forced aging were studied from the summarized points of microbiology, physics, chemistry, and biochemistry, and the resulted products ware compared in their physical, chemical and biochemical quality determining factors with that of raw material tobacco leaves (dried-tobacco leaves) and 2 years aged high quality tobacco leaves. The summary results were as follows. 1) The Korean flue-cured tobacco leaves, were forcedly aged under the basic optimum aging condition, temperature $40^{\circ}C$, moisture contents 18%, relative humidity 74%. It was found that this aging condition was the best in bringing the quality of forcedly aged tobacco leaves to the utmost state. 2) Under this optimum temperature and moisture condition of forced aging in about 20 days the forcedly aged tobacco leaves both with yeast inoculation and without yeast inoculation showed the equivalent tobacco qualities comparable with that of more than 2 years aged tobacco leaves. 3) The forcedly aged tobacco leaves both with and without yeast inoculation under $40^{\circ}C$ temperature and $74^{\circ}C$ relative humidity achieved the necessary quality determining physical and chemical changes in about 20 days. 4) The microbial changes during the forced aging were as follows. The population of yeasts and bacteria increased until to 15 days of aging, then decreased thereafter. Whereas the molds grew continously until the end of fermentation. 5) The tobacco quality determing physico-chemico-properties of yeast inoculated aged and simple forcedly aged tobacco leaves, progressed as the follows in time. As the forced aging progresses, swelling and combustibility properties were improved. The pH, total reducing materials, total sugars, alkaloids contents decreased. The contents of organic and ether extractable materials increased. The total nitrogen, protein, crude fiber, ash contents showed no changes. The color properties, excitation purity, luminance, main wave length, showed equivalent changes comparable with that of 2 years aged tobacco leaves. 6) The changes in chemical components in yeast treated and simple forcedly aged tobacco leaves during $15{\sim}20{\;}days$ of forced aging were as follows. The following chemical components decreased as the aging. Sugars-sucrose. rhamnose, glucose. Pigments-chlorophyll, carotenes, xanthophyll and violax anthine. Polyphenols-rutin, chlorogenic and, coffeic acid. Organic acids-iso-butylic, crotonic, caprylic, galacturonic, tartaric, succinic, citric acid. Alkaloids-nicotine, nornicotine. The following components increased as the forced aging progressed. Sugars-frutose, maltose, raffinose. Amino acids-proline, cystine. Organic acids-formic, acetic, propionic, n-butyric, iso-valeric, n-valeric, malic, oxalic, malonic, ${\alpha}-ketoglutaric$, fumaric, glutaric acid. 7) During the forced aging of tobacco Leaves the oxygen-uptake decreased gradually. The enzyme activities of polyphenol oxidase, ${\beta}-amylase$ ${\alpha}-amylase$ decreased gradually. The activities of the enzymes, catalase, and invertase increased once then decreased at the later stage.

• Tuberculosis and Respiratory Diseases
• /
• v.65 no.4
• /
• pp.301-307
• /
• 2008

Background: The triggering receptor expressed on myeloid cells-1 (TREM-1) is an activating receptor that is expressed on the surface of neutrophils and mature monocytes when stimulated with several microbial components, which can amplify the inflammatory response. This study analyzed the prognostic value of the sTREM-1 levels in patients with acute respiratory distress syndrome (ARDS). Methods: The bronchoalveolar lavage (BAL) fluid and blood was collected prospectively from 32 patients with ARDS, 15 survivors and 17 nonsurvivors. An enzyme-linked immunosorbent assay was performed to measure the sTREM-1. The following data was obtained: APACHE II score, Clinical Pulmonary Infection Score (CPIS), BAL fluid analysis, C-reative protein. Mortality in the ICU was defined as the end point. Results: The serum sTREM-1 level was significantly higher in the nonsurvivors than survivors ($54.3{\pm}10.3pg/ml$ vs. $22.7{\pm}2.3pg/ml$, p<0.05). The sTREM-1 level in the serum, but not in the BAL fluid, was an independent predictor of the ICU mortality (OR: 22.051, 95% CI: 1.780~273.148, p<0.016), and a cut-off value of ${\geq}33pg/ml$ yielded a diagnostic sensitivity of 71% and specificity of 93%. Conclusion: The serum sTREM-1 level may be a useful predictor of the outcome of ARDS patients.

• Korean Journal of Agricultural Science
• /
• v.7 no.2
• /
• pp.190-201
• /
• 1980

This experiment was designed to optimize the process of manufacturing the soybean cheeses and to elucidate the chemical changes during ripening when the chemical changes during ripening when the milk components and enzyme preparations were added to the raw materials. Conditions for extracting soybean protein such as temperature, duration and amount of water added were determined; various coagulaters were compared by checking the curd texture and yield; starters from S. thermophilus, S. lactis MLB and S. cremoris EB-9 were tested as single- or multi-stain combinations; and the effects of skim milk and/or rennins-both microbial and calf origin-addition upon the process of manufacturing and ripening were studied. The results obtained were as follows. 1. optimal conditions for soybean extraction were found to be: temperature $100^{\circ}C$, duration 10 minutes, and amount of water added 9-fold, as considered the extraction rate of solids and proteins, and curd yield. 2. Sodium gluconate was the most effective among the coagulators tested, and 5% of single-strain starter from S. thermophilus was appered to be adequate inoculum for curd formation. 3. The effects of skim milk and/or rennins addition on the process of manufacturing and ripening of soybean cheeses were: 1) The addition of rennins resulted in fast formation of curd, especially with skim milk it was so. And Hansen rennet extracts brought better results in curd formation than Meito rennet extracts did. 2) No significant effect was observed on the changes in moisture content during ripening, however the levels of moisture contents in the products were higher in case of using Meito rennet extracts. 3) Effect on pH changes during ripening was also not significant in general, while levels of pH were decrease markedly during manufacturing and the initial stage of ripening. 4) The levels of bacterial counts were much higher in case of skim milk addition throughtout the ripening period. In general the numbers were reached to approximately $10^8cells/g$ during manufacturing, then decreased gradually to below $10^2cells/g$ in 8 weeks of ripening. 5) The addition of skim milk and/or rennin resulted in higher ripening index, and skim milk plus Meito rennet extracts was appeared to be best combination for the ripening index.

• Microbiology and Biotechnology Letters
• /
• v.42 no.3
• /
• pp.267-274
• /
• 2014

High pressure processing (HPP) is a non-thermal method used to prevent bacterial growth in the food industry. Currently, pasteurization is the most common method in use for most milk processing, but this has the disadvantage that it leads to changes in the milk's nutritional and chemical properties. Therefore, the effects of HPP treatment on the microbiological and chemical properties of milk were investigated in this study. With the treatment of HPP at 600 MPa and $15^{\circ}C$ for 3 min, the quantity of microorganisms and lactic acid bacteria were reduced to the level of 2-3 log CFU/ml, and coliforms were not detected during a storage period of 15 d at $4^{\circ}C$. An analysis of milk proteins, such as ${\alpha}$-casein, ${\beta}$-casein, ${\kappa}$-casein, ${\alpha}$-lactalbumin, ${\beta}$-lactoglobulin by on-chip electorophoresis revealed that the electrophoretic pattern of the proteins from HPP-treated milk was different from that of conventionally treated commercial milk. While the quantities of vitamins and minerals in HPP-treated milk were seen to be comparable to amounts found in raw milk, the enzyme activity of lipase, protease and alkaline phosphatase after HPP treatment was reduced. These results suggest that HPP treatment is a viable method for the control of undesirable microorganisms in milk, allowing for minimal nutritional and chemical changes in the milk during the process.

• Journal of Animal Environmental Science
• /
• v.18 no.sup
• /
• pp.47-54
• /
• 2012

Effect of commercial Direct Fed Microbials (DFM) or protease treated feed (PTF) supplementation on growth rate and biogenic substances such as BUN, glucose, IgG, GOT, GPT and Vitamin A, C, E from Holstein steers was studied for 7 months. Thirty two steers aged 2~3 months were separated with 4 groups for control, DFM (PS), protease (ES) and their mix (PS + ES) supplementally fed 0, 100, 100 and 50 + 50 g/day respectively. Weight gain was averagely higher in PS than any others, although there were no differences significantly. All treatments enhanced to 3~8% of control in dry matter, crude protein and total digestible nutrient (P>0.05). Metabolic diseases with veterinary cure had not shown in this study. Plasma GOT and GPT were lower in the PS and ES than control. Plasma glucose concentration was also lower in PS than the others. Total cholesterol of ES was higher than the others but that of PS is the lowest. Plasma vitamin C was higher in PS than the others. It was shown that dietary PS affected change from glucose to vitamin C with not overloading liver. Conclusionally, PS and ES were shown to enhance metabolic health of steers during growing period.

• Food Science and Preservation
• /
• v.31 no.1
• /
• pp.149-160
• /
• 2024

Dextran is a glucose homo-polysaccharide with a predominantly α-1,6 glycosidic linkage of microbial source and is known to be produced primarily by lactic acid bacteria. However, it can also be obtained through the dextran dextrinase of acetic acid bacteria (Gluconobacter oxydans). The dextrin-based dextran was obtained from rice starch using G. oxydans fermentation of rice hydrolysate, and its properties were studied. Both dextrin- and rice hydrolysate-added media maintained the OD value of 6 after 20 h of incubation with acetic acid bacteria, and the gel permeation chromatography (GPC) analysis of the supernatant after 72 h of incubation confirmed that a polymeric material with DP of 480 and 405, which was different from the composition of the substrate in the medium, was produced. The glucose linkage pattern of the polysaccharide was confirmed using the proton nuclear magnetic resonance (¹H-NMR) and the increased α-1,4:α-1,6 bond ratio from 0.23 and 0.13 to 1:2.37 and 1:4.4, respectively, indicating that the main bonds were converted to α-1,6 bonds. The treatment of dextrin with a rat-derived alpha-glucosidase digestive enzyme resulted in a slow release of glucose, suggesting that rice hydrolysate can be converted to dextran using acetic acid bacteria with glycosyltransferase activity to produce high-value bio-materials with slowly digestible properties.