• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.3
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• pp.358-365
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• 1999

The effects of dry roasting whole lupin seeds (lupinus albus, WLS) at 110, 130 or $150{^{\circ}C}$ for 15, 30 or 45 minutes on the in sacco rumen degradation characteristics, optimal heating conditions of time and temperature and in vitro enzyme digestibility were determined. Ruminant degradation characteristics (RDC) of crude protein (CP) of WLS were determined by in sacco technique in dairy cows. Measure ROC were soluble (S), undegradable (U), potentially degradable (D) fractions, lag time (TO) and rate of degradation (Kd) of insoluble but degradable fraction. Based on measured ROC, percentage bypass CP (%BCP) and bypass CP (BCP in g/kg, DM) were calculated. Degradability of CP was significantly reduced by dry roasting (p<0.001). The interaction of dry roasting temperature and time had significant effects on D (p<0.05), Kd (p<0.01), U (p<0.01), %BCP (p<0.001) and BCP (p<0.001) but not on S (p=0.923>0.05). With increasing time and temperature, S, D, Kd and U varied from 31.8%, 67.4%, 10.3%/h and 0.8% in the raw WLS (RWLS) to 27.1 %, 35.8%, 3.6%/h, 38.4% in $150{^{\circ}C}/45\;min$, respectively. All these effects resulted in increasing %BCP from 25.9 in RWLS to 61.0% in the $150{^{\circ}C}/45\;min$. Therefore BCP increased form 111.2 to 261.2 g/kg DM, respectively. Both %BCP and BCP at $150{^{\circ}C}/45\;min$ increased nearly 2.5 times over the RWLS. The effects of dry roasting on %BCP and BCP seemed to be linear up to the highest value tested. Although ROC had been altered by dry roasting, the In vitro perpsin-cellulase digestibility was generally unchanged. It was concluded that dry roasting was effective in shifting CP degradation from rumen to the lower gastrointestinal tract to potential reduce unnecessary N loss in the rumen. It might be of great value in successfully synchronizing the rhythms of release of nitrogen and energy in the rumen, thus achieving a more efficient fermentation of diets with high proportions of lignocellulosic resources. To determine the optimal dry roasting conditions, the digestibility of each treatment in the cows will be measured in the next trial using mobile bags technique.

• Food Science and Preservation
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• v.17 no.6
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• pp.881-888
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• 2010

We investigated the influence of carbonic maceration (CM) at different temperatures on the enological characteristics of Campbell Early grape must. Total acid levels decreased after 5 d, as CM temperature increased. All of pH; redness; and total anthocyanin, polyphenol, and tannin concentrations increased as CM temperature increased. Malic acid concentration fell at high CM temperatures, but lactic acid level increased under such conditions. Polyphenol levels and antioxidant activity were higher when CM was conducted at $35^{\circ}C$ than at other temperatures. The results show that the temperature of CM treatment greatly influences wine quality factors such as color, taste, and antioxidant capacity.

• Journal of Animal Science and Technology
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• v.55 no.4
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• pp.273-280
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• 2013

This study was conducted to investigate the effects of fermented king oyster mushroom by-products diet (FMBD) on the growth performance, blood characteristics, and carcass traits of fattening pigs and its economics. The fermented diet mainly contained 40.0% king oyster mushroom (Pleurotus eryngii) by-products, 20.0% corn, 28.0% soybean meal, 0.1% supplemental probiotics and 0.08% cellulase. The mixed ingredients were fermented for 1 d at $37^{\circ}C$ followed by 9 d at room temperature, after which they were dried at $45^{\circ}C$ for 3 d. Pigs (n=96) were divided into eight heads per pen, four diet treatments and three replications. The basal diet (C) was substituted with 20% (T1), 50% (T2) and 80% (T3) FMBD. The concentration of crude protein (CP) was significantly higher (p<0.05) at the end of the fermentation period. The average daily gain (ADG) and feed efficiency were significantly lower (p<0.05) in T3 than C. Additionally, carcass grade was significantly better (p<0.05) in all treatments than C and the ratio of high carcass grade was higher. Although substitution of FMBD decreased growth performance, it improved carcass grade and decreased the feed cost of fattening pigs. Therefore, it was expected that the increase in the utilization ratio of FMBD will reduce the cost of animal production.

• Food Science of Animal Resources
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• v.33 no.5
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• pp.595-602
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• 2013

As a major inhibitory neurotransmitter of the central nervous system in animals, ${\gamma}$-aminobutyric acid (GABA) has several physiological functions, such as anti-hypertensive, diuretic, tranquilizer and anti-stress effects in human. In order to determine strains with high GABA producing ability and glutamate decarboxylase (GAD) activity, 273 bacteria were isolated from various types of Kimchi. Strain K255 contained $386.37{\mu}g/mL$ of GABA in MRS broth containing 1% MSG, $600.63{\mu}g/mL$ of GABA in MRS broth containing 2% MSG and $821.24{\mu}g/mL$ of GABA in MRS broth containing 3% MSG. It showed that K255 had the highest GABA production ability compared to other commercial lactic acid bacteria. K255 was identified as Lactobacillus plantarum based on its API carbohydrate fermentation pattern and 16S rDNA sequence. K255 was investigated for its physiological characteristics. The optimum growth temperature of K255 was $37^{\circ}C$and cultures took 13 h to reach the pH 4.4. K255 showed more sensitive to bacitracin in a comparison of fifteen different antibiotics, and showed most resistance to kanamycin and vancomycin. Moreover, it was comparatively tolerant to bile juice and acid and displayed resistance to Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus, with rates of 30.8%, 29.7%, and 23.4% respectively. These results demonstrate that K255 could be an excellent strain for the production of functional products.

• Microbiology and Biotechnology Letters
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• v.14 no.6
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• pp.461-466
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• 1986

A highly cyclodextrin glucanotransferase producing strain of Bacillus sp. was isolated from soil, and basic studies on the characteristics of the strain and its enzyme, conditions for the enzyme production, and the enzyme utilization were carried out. The isolated strain was aerobic, motile, endospore-forming and rod-shaped bacterium. Optimum pH and temperature for the enzyme action were 6.0 and 45$^{\circ}C$, and the enzyme was stable within 5$0^{\circ}C$, and between pH 6.0 and 10.0. The highest yield of the enzyme was obtained using the medium containing 2% corn starch as a carbon source, and 5% corn steep liquor, 0.1% urea and 0.25% ammonium sulfate as nitrogen sources. The fermentation conditions for the enzyme production in a jar fermentor were cetermined to be 3$0^{\circ}C$, 200rpm, 0.6vvm and 60hr cultural period. Stevioside transglycosylation catalyzed by this enzyme was identified by high performance liquid chromatography.

• Journal of Microbiology and Biotechnology
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• v.26 no.4
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• pp.666-674
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• 2016

The bacterial strains were screened as potential starters for fermenting low-salt doenjang (a Korean traditional fermented soybean paste) using Korean doenjang based on proteolytic and antipathogenic activities under 6.5-7.5% NaCl conditions. Phylogenetic analysis based on 16S rRNA gene sequences showed that they all belonged to the genus Bacillus. Proteolytic and antipathogenic activities against Escherichia coli, Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, and Aspergillus flavus, as well as fibrinolytic, amylase, and cellulase activities of the 10 strains were quantitatively evaluated. Of these, strains D2-2, JJ-D34, and D12-5 were selected, based on their activities. The functional, phenotypic, and safety-related characteristics of these three strains were additionally investigated and strains D2-2 and D12-5, which lacked antibiotic resistance, were finally selected. Strains D2-2 and D12-5 produced poly-γ-glutamic acid and showed various enzyme activities, including α-glucosidase and β-glucosidase. Growth properties of strains D2-2 and D12-5 included wide temperature and pH ranges, growth in up to 16% NaCl, and weak anaerobic growth, suggesting that they facilitate low-salt doenjang fermentation. Strains D2-2 and D12-5 were not hemolytic, carried no toxin genes, and did not produce biogenic amines. These results suggest that strains D2-2 and D12-5 can serve as appropriate starter cultures for fermenting low-salt doenjang with high quality and safety.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.452-461
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• 2012

Four, ruminally fistulated crossbred (Brahman${\times}$native) beef cattle with initial body weight of $420{\pm}15kg$ were randomly assigned according to a $4{\times}4$ Latin square design. The dietary treatments were mulberry leaf pellet (MUP) supplementation at 0, 200, 400 and 600 g/hd/d with rice straw fed to allow ad libitum intake. All steers were kept in individual pens and supplemented with concentrate at 5 g/kg of body weight daily. The experiment was 4 periods, and each lasted 21 d. During the first 14 d, all steers were fed their respective diets ad libitum and during the last 7 d, they were moved to metabolism crates for total urine and fecal collection. It was found that increasing MUP levels resulted in linearly increasing rice straw and total intakes (p<0.05). Ruminal temperature and pH were not significantly affected by MUP supplementation while $NH_3$-N concentration was increased (p<0.05) and maintained at a high level (18.5 mg/dl) with supplementation of MUP at 600 g/hd/d. Similarly, viable total bacteria in the rumen and cellulolytic bacteria were enriched by MUP supplementation at 600 g/hd/d. However, the rumen microbial diversity determined with a PCR-DGGE technique showed similar methanogenic diversity between treatments and sampling times and were similar at a 69% genetic relationship as determined by a UPGMA method. Based on this study, it could be concluded that supplementation of MUP at 600 g/hd/d improved DM intake, ruminal $NH_3$-N, and cellulolytic bacteria thus iimproving rumen ecology in beef cattle fed with rice straw.

• Korean Journal of Environmental Agriculture
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• v.35 no.4
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• pp.294-301
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• 2016

BACKGROUND: Recent studies have described the importance of microbes and enzymes that can compost food waste. This study was carried out to improve production of protease of isolated microbes from food waste. METHODS AND RESULTS: Seven bacteria isolated from various sources were screened for protease production by adding skim milk into the agar medium. About 7 microbes producing protease were tested, and strain JH-35 showed the highest protease activity among them. The strain was identified as Bacillus amyloliquefaciens JH-35 based on morphological, cultural, physiological characteristics and 16S rRNA. In the fermentation experiment, the assay B. amyloliquefaciens JH-35 showed the highest protease activity in the condition of 1% glucose, 1.5% yeast extract and 0.2%$ K_2HPO_4$. The optimal condition of culture with temperature $35^{\circ}C$, initial pH of 7 and shaking speed of 200 rpm and 24 hr. CONCLUSION: The protease of the B. amyloliquefaciens JH-35 had its activity at pH 7 and the optimal culture time was 24 hr. Also, B. amyloliquefaciens JH-35 was high salt tolerance. Our results suggest that B. amyloliquefaciens JH-35 from food waste may have the potential to degrade protein and carbohydrate in food waste.

• Journal of Biosystems Engineering
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• v.41 no.4
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• pp.365-372
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• 2016

Purpose: Tea is the most frequently consumed drink worldwide, next to water. About 75% of the total world tea production includes black tea, and withering is one of the major processing steps critical for the quality of black tea. There are two types of tea withering methods: physical and chemical withering. Withering can be achieved by using tat, tunnel, drum, and trough withering systems. Of these, the trough withering system is the most commonly used. This study focuses on the different types of withering, their effect on the various quality attributes of tea, and other aspects of withering methods that affect superior quality tea. Results: During physical withering, tea shoots loose moisture content that drops from approximately 70-80% to 60-70% (wet basis). This leads to increased sap concentration in tea leaf cells, and turgid leaves become flaccid. It also prevents tea shoots from damage during maceration or rolling. During chemical withering, complex chemical compounds break down into simpler ones volatile flavor compounds, amino acids, and simple sugars are formed. Withering increases enzymatic activities as well as the concentration of caffeine. Research indicates that about 15% of chlorophyll degradation occurs during withering. It is also reported that during withering lipids break down into simpler compounds and catechin levels decrease. Improper withering can cause adverse effects on subsequent manufacturing operations, such as maceration, rolling, fermentation, drying, and tea storage. Conclusion: Freshly harvested leaves are conditioned physically and chemically for subsequent processing. There is no specified withering duration, but 14-18 h is generally considered the optimum period. Proper and even withering of tea shoots greatly depends on the standards of plucking, handling, transportation, environmental conditions, time, and temperature. Thus, to ensure consumption of high quality tea, the withering step must be monitored carefully.