• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.40-46
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• 2014

We have screened Bacillus strains suitable for the fermentation of soybean products with respect to the control of Bacillus cereus and the reduction of biogenic amines. Of 26 isolates, a strain named as the SCK A08 carried antimicrobial activity against B. cereus and Staphylococcus aureus, major food poisoning species in soybean products. PCR analysis revealed that the SCK A08 strain did not contain genes for Bacillus cereus toxins including nonhemolytic enterotoxin, hemolytic enterotoxin, cytotoxin K, cereulide and certrax. The SCK A08 strain could degrade histamine, tyramine, putrescine, and cadaverine by 67.41%, 76.59%, 57.32%, and 50.69%, respectively, during fermentation in cooked soybeans containing 0.5% (w/w) of each biogenic amine. The morphological and biochemical properties and phylogenetic relationships based on 16S rRNA gene sequences indicated that the isolate was most closely related to Bacillus licheniformis. Use of the strain SCK A08 would be a potential measure to overcome two hygienic problems that were frequently faced during manufacture of traditionally fermented soybean products.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.251-256
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• 2017

Some rhizobacteria were isolated, that have copper resistance and can confer copper resistance to plants allowing growth under copper stress. Isolated strains Pseudomonas veronii MS1 and P. migulae MS2 produced 0.13 and 0.26 mmol/ml of siderophore, that is a metal-chelating agent, and also showed 64.6 and 77.9% of biosorption ability for Cu in 20 mg/L Cu solution, respectively. Copper can catalyze a formation of harmful free radicals, which may cause oxidative stress in organisms. Removal activity of 1,1-diphenyl-2-picryl hydrazyl radical and antioxidant capacity of strains MS1 and MS2 increased up to 82.6 and 78.1%, respectively compared to those of control at 24 h of incubation. They exhibited 7.10 and $6.42{\mu}mol$ ${\alpha}$-ketobutyrate mg/h of 1-aminocyclopropane-1-carboxylic acid deaminase activity, respectively, which reduced levels of stress hormone, ethylene in plants, and also produced indole-3-acetic acid and salicyclic acid that can help plant growth under abiotic stress. All these results indicated that these copper-resistant rhizobacteria could confer copper resistance and growth promotion to plants.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.273-285
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• 2017

The purpose of this study was to investigate the inhibitory effect of antibacterial substances produced by probiotic lactic acid bacteria (LAB) against biogenic amines-producing bacteria and the influence of culture conditions on the antibacterial activity of bacteriocin and organic acid. The bacteriocin solutions of Lactobacillus plantarum FIL20 (64 AU/ml) and Lactobacillus paracasei FIL31 (128 AU/ml) showed strong antibacterial activity against Serratia marcescens CIH09 and Aeromonas hydrophilia RIH28, respectively. And the lactic acid contents in the cell-free culture supernatants (CFCS) obtained from FIL20 and FIL31 strains were $107.3{\pm}2.7mM$ and $129.5{\pm}4.6mM$, respectively. Therefore, the bacteriocin solution (200 AU/ml) and the CFCS ($200{\mu}l/ml$) produced by L. plantarum FIL20 and L. paracasei FIL31 significantly (P < 0.05) decreased the bacterial numbers and histamine and tyramine production ability of S. marcescens CIH09 and A. hydrophilia RIH28. The amounts of histamine and tyramine produced by the CIH09 strain under conditions of low initial pH (5.0) and incubation temperature ($15^{\circ}C$) was significantly reduced by treatment with bacteriocin solution and CFCS obtained from L. plantarum FIL20. In addition, the bacterial counts and biogenic amines contents of CIH09 strain were significantly decreased (P < 0.05) when sodium chloride (5%) or potassium nitrite (200 mg/g) were mixed with the antibacterial substances of L. plantarum FIL20. Consequently, the bacteriocin and organic acid solution of L. plantarum FIL20 and L. paracasei FIL31 can be used as a biological preservation to effectively control the production of biogenic amines by the application of hurdle technology.

• Korean Journal of Poultry Science
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• v.40 no.1
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• pp.25-29
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• 2013

This study was conducted to evaluate the antimicrobial and antioxidant effects of ripened medicinal herb extracts from wood vinegar. The wood vinegar was collected from heated oaks. The Allium sativum (AS), Atractylodes ovate (AO), Cin-namomum zeylanicum (CZ), Coptidis rhizome (CR), Houttuynia cordata (HC), Phellodendron chinense (PC) and Syzygium aromaticum (SA) extracts were collected using wood vinegar, and they were ripened under room temperature for 50 days. All ripened medicinal herb extracts were used to test the antimicrobial and antioxidant activities. For the Lactobacillus, clear zone of 6 different medicinal herb except for CR ranged from 1.28 to 1.63 mm. 3.30 and 3.48 mm of clear zone were determined when CZ and SA were applied to Salmonella and E. coli, respectively (p<0.05), and they showed the largest clear zone as compared to other herbs. The clear zones of CR for Salmonella and E. coli were 2.21 and 3.34 mm, and each clear zone of CR was smaller than that of CZ (p<0.05) but was similar to that of SA (p>0.05). The amount of polyphenol and flavonoid was the highest in SA and CR, and they were 4.28 and 0.38 mg/mL, respectively (p<0.05). The CR shown 0.38 mg/mL flavonoid, had the highest DPPH, and it was 0.41 mM. The DPPH of HZ was significantly lowered in accordance with high amount of polyphenol and flavonoid, 2.56 and 0.20 mg/mL (p<0.05). In conclusion, CZ, SA, and CR showed high antimicrobial and antioxidant potentials, and therefore, may be used as alternatives to antibiotics for poultry diets.

• Journal of Life Science
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• v.29 no.12
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• pp.1378-1385
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• 2019

The nutritional composition and optimal eating stage of the super mealworm, Zophobas atratus (Coleoptera : Tenebrionidae), were investigated to explore its use as a food ingredient. It was determined that 10^th instar larvae were most suitable for eating in terms of nutritional value as well as economic aspects. To improve the quality of powder production, the nutritional value of 10^th instar larvae before and after degreasing was analyzed. After drying the larvae powder, crude protein was the most abundant nutrient both before (52.3%) and after (60.6%) degreasing while crude fat measured 36.3% and 21.7% before and after degreasing, respectively. In terms of essential amino acids, leucine levels were highest and 1.3 times greater after degreasing (4.5%) than before (3.5%). Oleic acid, the highest unsaturated fatty acid in larvae, was 31.7% after degreasing which was 1.1 times higher than before (33.2%). Among various major minerals, potassium was most abundant and 1.4 times higher after degreasing (1267.0 mg/100 g) than before (879.3 mg/100 g). Harmful substances were 1.3 to 2.0 times lower in the degreased larvae, although mercury or pathogenic bacteria were not detected in either group. We therefore conclude that degreased Z. atratus larvae are more suitable for eating than before degreasing.

• Journal of Life Science
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• v.30 no.12
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• pp.1109-1117
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• 2020

In order to verify whether Zophobas atratus is an edible insect, the nutrients and harmful substances of Z. atratus larvae reared with an artificial diet (AD) and wheat bran (WB) were compared and analyzed. Based on dry weight, the crude protein content of Z. atratus larvae reared with an AD was 62.4%, 1.4 times higher than that of those reared with WB (45.2%). The crude fat content was 20.5% in the AD group, 2.3 times less than in the WB group (46.3%). The leucine content was 1.4 times higher in the AD group (4.2%) than in the WB group (3.0%). The glutamic acid content of nonessential amino acids was 1.3 times higher in the AD group (7.0%) than in the WB group (5.3%). The oleic acid content was 1.4 times higher in the WB group (37.0%) than in the AD group (26.7%). The potassium content was 1.1 times higher in the AD group (975.9 mg/100 g) than in the WB group (872.9 mg/100 g). According to the results of the toxic substances analysis, the lead and cadmium levels of the WB and AD groups were standard for edible insects. Pathogenic microorganisms, such as E. coli and salmonella, were not detected in either group. According to the results of the present analysis of nutrition and harmful substances, Z. atratus larvae raised on an AD are safe and contain various nutrients. Therefore, such larvae could be useful sources of food and feed.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.348-354
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• 2013

BACKGROUND: Globally, concern about emerging infectious diseases of livestock is growing. For the disposal of the animal carcass, it is necessary to recycle the carcass into an agriculturally usable product. The objective of this study was to investigate the composting conditions of liquid by-product obtained from degradation of animal carcass. METHODS AND RESULTS: Optimum conditions of liquid fertilizer were investigated using different microorganisms, pHs, and volumes of microorganisms (Lactobacillus rhamnosus+Pichia deserticola). Based on the results from the optimum conditions, compost maturity and quality of liquid fertilizer were evaluated for 112 days. The compost maturity of liquid fertilizer were higher in the order of LP(Lactobacillus rhamnosus + Pichia deserticola) > BC(Bacillus cereus) > BS(Bacillus subtilis). The optimum condition under different volumes of LP was injection of 0.5 mL/100 mL. The compost maturity under different pHs were higher in the order of pH 7 > $$5{\geq_-}9{\frac{._-}{.}}11$$. The liquid by-product at 56 days after composting was completely decomposed. The concentrations of T-N, T-P and $K_2O$ in liquid fertilizer at 56 days were 0.94, 0.17 and 3.78%, respectively, and the sum of those concentrations was 4.89%. CONCLUSION(S): Liquid fertilizer of by-product using pig carcass was decomposed with optimum conditions(LP, pH 7, injection of 0.5 mL/100 mL) in 56 days after composting, and was suitable for official standard of commercial fertilizer.

• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.129-138
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• 2007

A natural deodorizing agent (NDA) was made using pine cone byproduct, and its effects on malodor emission and composting were analyzed in this study. NDA was manufactured by mixing pine cone byproduct with three species of microorganisms and water containing mineral nutrients and molasses, and then by incubating for 48 hours at $30^{\circ}C$. Lab scale experiments were done with three treatment groups, T1 (control, sawdust treatment), T2 (microorganisms and sawdust treatment group), and T3 (NDA and sawdust treatment group). During composting, temperatures reached over $55^{\circ}C$, a minimum temperature for the inactivation of pathogenic microorganisms. No differences were found in physicochemical composition of compost among treatments. However, it was observed that over usage of NDA could obstruct temperature increase, since the biodegradation rate of organic matter of NDA was relatively low, Nitrogen loss due to ammonia gas emission, which normally happens during composting, was reduced by using NDA, and hence the nitrogen level of final compost was higher in T3 than in others. During experiment, it was found that ammonia gas emission was entirely lasted through compositing duration, but the $CH_3SH$ and $H_2S$ gases were produced only at early stage of composting. The ammonia concentration trapped in $H_2SO_4$ solution during 31 days of composting in T1, T2 and T3 was 12,660mg/L, 11,598mg/L and 7,367mg/L, respectively, showing distinguishable reduction of ammonia gas emission in T3. The emissions of $CH_3SH$ and $H_2S$ gases were also remarkably reduced in T3. Based on these obtained results, usage of the deodorizing agent made with pine cone byproduct could reduce the emission of malodor during composting, without any deterioration of compost quality.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.569-576
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• 2003

An experiment was conducted to investigate the effect of microbial phytase (Natuphos$^{\circledR}$) supplementation, individually and in combination with carbohydrase enzyme complex (composed of enzymes targeted to SBM dietary components such as $\alpha$-galactosides and galactomannans; ENDO-POWER$^{\circledR}$) to corn-soy basis diet with low nutrient levels on growth performance and nutrient digestibility of growing pigs. A total of 48 crossbred weaned pigs (Landrace${\times}$Yorkshire${\times}$Duroc), 29.1$\pm$0.14 kg of initial body weight, were randomly allotted to four dietary treatments, based on weight and age, according to a Randomized Complete Block Design. There were three pens per treatment and 4 pigs per pen. The dietary treatments were 1) CON (control diet with 3,380 kcal/kg of metabolizable energy, 18.96% of crude protein, 1.10% of lysine, 0.75% of calcium and 0.35% of available phosphorus), 2) LP+NTPS (CON diet with 0.15% unit lower available P levels+0.1% phytase (500 FTU/kg; Natuphos$^{\circledR}$)), 3) LEL+ENP (CON diet with 3.0% unit lower ME and lysine levels + 0.1% carbohydrase enzyme complex (ENDO-POWER$^{\circledR}$), and 4) LPEL+ENZ (CON diet with 0.15% unit lower available P levels and 3.0% unit lower ME and lysine levels+0.1% ENDO-POWER$^{\circledR}$ and 0.1% Natuphos$^{\circledR}$ (500 FTU/kg). There was no significant difference (p〉0.05) in average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR) among dietary treatments during the whole experimental period (0 to 4 weeks). Apparent digestibility of gross energy was greater in LP+NTPS and LPEL+ENZ groups than in the LEL+ENP (p<0.05). Apparent digestibility of phosphorus was greater in LP+NTPS than in LEL+ENP (p<0.05). Dry matter excretion was lowest in LPEL+ENZ and phosphorus excretion was lowest in LP+NTPS (p<0.05). Overall, pigs fed on LPEL+ENZ group tended to have better nutrient digestibility (dry matter, gross energy, crude protein and phosphorus) than pigs fed on control group. All dietary enzyme treatment groups showed lower feed cost/body weight gain of pigs than control group. In conclusion, the results from the present study suggest that the simultaneous inclusion of phytase and carbohydrase enzyme complex to diets is advantageous with respect to reducing nutrient excretion of growing pigs and may contribute to increased economic return when added to corn-soy based growing pig diets.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.632-637
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• 1996

Effects of refrigeration temperature and its fluctuation range on the growth of psychrotrophic microorganisms and the quality of refrigerated foods such as apple, fish and oyster were evaluated to find optimum storage conditions for a domestic refrigerator. Refrigeration temperature was $2^{\circ}C$ or $4^{\circ}C$, and fluctuation ranges were varied: ${\pm}0.3,\;{\pm}1.0,\;{\pm}1.2,\;or\;{\pm}4.0^{\circ}C$. Changes in hardness of apples stored at $2{\pm}0.3^{\circ}C$ were much slower than those of apples stored at $4{\pm}1.2^{\circ}C$. Freshness of fish and oyster also lasted much longer at low temperature such as $2{\pm}0.3^{\circ}C$. The growth of Listeria monocytogenes inoculated on sliced ham was inhibited for 1 month at $2{\pm}0.3^{\circ}C$, but the cells at $4{\pm}1.2^{\circ}C$ began to grows as time elapsed. Therefore, it was expected that shelf-life of certain food stored in a domestic refrigerator could be extended by lowering temperature to $2^{\circ}C$ and by reducing fluctuation range of refrigerator.