• KSBB Journal
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• 제27권6호
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• pp.352-360
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• 2012

Bacillus clausii I-52 which produced SDS- and $H_2O_2$-tolerant extracellular alkaline protease (BCAP) was isolated from heavily polluted tidal mud flat of West Sea in Incheon, Korea and stable strain (transformant C5) of B. clausii I-52 harboring another copy of BCAP gene in the chromosome was developed using the chromosome integration vector, pHPS9-fuBCAP. When investigated the production of BCAP using B. clausii transformant C5 through pilot-scale submerged fermentation (500 L) at $37^{\circ}C$ for 30 h with an aeration rate of 1 vvm and agitation rate of 250 rpm, protease yield of approximately 105,700 U/mL was achieved using an optimized medium (soybean meal 2%, wheat flour 1%, sodium citrate 0.5%, $K_2HPO_4$ 0.4%, $Na_2HPO_4$ 0.1%, NaCl 0.4%, $MgSO_4{\cdot}7H_2O$ 0.01%, $FeSO_4{\cdot}7H_2O$ 0.05%, liquid maltose 2.5%, $Na_2CO_3$ 0.6%). The enzyme stability of BCAP was increased by addition of polyols (10%, v/v) and also, the stabilities of BCAP towards not only the thermal-induced inactivation at $50^{\circ}C$ but also the SDS and $H_2O_2$-induced inactivation at $50^{\circ}C$ were enhanced. Among the polyols examined, the best result was obtained with propylene glycol (10%, v/v). The BCAP supplemented with propylene glycol exhibited extreme stability against not only the detergent components such as ${\alpha}$-orephin sulfonate (AOS) and zeolite but also the commercial detergent preparations. The granulized enzyme of BCAP was prepared with approximately 1,310,000 U/g of granule. Wash performance analysis using EMPA test fabrics revealed that BCAP granule exhibited high efficiency for removal of protein stains in the presence of anionic surfactants as well as bleaching agents. When compared to Savinase 6T$^{(R)}$ and Everlase 6T$^{(R)}$ manufactured by Novozymes, BCAP under this study probably showed similar or higher efficiency for the removal of protein stains. These results suggest that the alkaline protease produced from B. clausii transformant C5 showing high stability against detergents and high wash performance has significant potential and a promising candidate for use as a detergent additive.

• 한국미생물·생명공학회지
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• 제49권2호
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• pp.255-263
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• 2021

γ-Aminobutyric acid 생성에 관여하는 glutamate decarboxylase 유전자 gadA/B를 보유한 메주 유래 Enterococcus faecium 88균주를 대상으로 기능적 특성 및 안전성 평가를 진행하여 메주 유래 E. faecium의 발효식품용 종균으로써의 활용 가능성을 검토하였다. 6% NaCl 농도(w/v)에서 모든 균주의 생장 및 산 생성이 확인되었다. 7% NaCl 농도에서는 21균주(24%)가 낮은 생장을 나타냈으며, 72균주(82%)가 약한 산 생성 활성을 나타냈고, 16균주(18%)는 산생성을 나타내지 않았다. 4% NaCl 농도에서는 모든 균주가 단백질 분해 활성을 나타냈지만, 5% NaCl 농도에서 86균주(98%)가 약한 활성을 나타냈고, 1균주(1%)는 활성을 나타내지 않았다. 지방 분해 활성은 모든 균주에서 나타나지 않았다. 모든 균주가 7종의 항생제(ampicillin, chloramphenicol, ciprofloxacin, gentamicin, penicillin G, tetracycline, vancomycin)에 대해 획득형 항생제 내성을 나타내지 않았다. Enterococcus 심내막염 항원 유전자 efaA 및 tyramine 생성에 관여하는 tyrosine decarboxylase 유전자 tdc가 메주 유래 88균주에서 발견되었지만, 사람 기원 E. faecium 균주가 특이적으로 보유하고 있는 Enterococcus surface protein 유전자 esp는 발견되지 않았다.

• 한국가금학회지
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• 제13권2호
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• pp.209-219
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• 1986

본 실험에서는 식물성이면서 포화도가 높은 팜유와 동물성이면서 불포화도가 높은 어유를 병아리에 섭취시켜 혈액과 간내의 cholesterol 및 TG 함량에 미치는 영향을 조사하는데 그 목적을 두었다. 그 결과 에너지 섭취량은 각 첨가 지방의 에너지가가 g당 9kcal로 가정하고 다른 원료 사료들은 각각의 대사에너지 함량을(Scott, 1976) 기준해서 계산하였는데 그 결과 지방 첨가 수준이나 첨가 지방의 종류에 관계없이 에너지 섭취량이 전반적으로 비슷하게 나타났다. 체중 증가량도 대체로 처리간에 통계적인 처리가 없었고, 단지 실험 1에서 동물성 지방급여구가 식물성 지방급여구보다 유의하게 적게 나타났다. 그리고 체중 100g당의 무게로 나타냈을때 간의 무게는 실험 1의 어유구와 실험2의 경화어유구에서 각각 가장 무거웠고, 심장의 무게는 실험2에서 두 어유구가 모두 가장 무겁게 나타났다. 한천 간장의 총지방 함량은 실험2에서 우지구가 팜유구보다 유의하게 더 많았다. 고리고 간장의 cholesterol 함량은 실험1에서만 어유구가 팜유나 우지구보다 더 높게 나타났고, 혈액 cholesterol 함량은 실험2에서 어유구가 가장 낮았다(P〈0.05). 또 간장의 TG함량은 실험2에서 채종유, 우지 및 경화어유구등이 팜유구보다 더 높았고, 실험3에서는 C/P 비율이 164인 구가 대조구보다 간에 더 많은 TG를 함유한 것으로 나타났다 (P〈0.05). 그러나 혈액 TG는 전반적으로 개체 변이가 심해서 유의한 차이를 볼 수 없었다. 이상의 결과를 다시 첨가된 각 지방별로 요약하면, 옥수수유, 대두유, 채종유등은 여러 측정치에서 유사한 결과를 보여주었고, 채종유의 경우에는 심잠의 무게를 증가시킬 것으로 예상했었으나 그렇지 않았다. 그리고 팜유는 우지나 경화어유보다 간의 총지방 함량이나 간장의 TG를 더 낮추는 효과를 보였고 cholesterol에 대한 효과도 다른 식물성 지방과 유사하게 나타났다. 어유는 실험 1에서 간의 중량을 무겁게 하고, 간내의 cholesterol 함량을 높였는데 실험2에서는 심장의 무게를 각각 무겁게 했고 한편 혈액 cholesterol을 가장 낮은 수준으로 떨어뜨렸다. 그런데 실험 1과 2에서 사용된 어유는 각각 다른 source에서 구한 것으로서 여러 어종의 것이 아니기 때문에 비교하기가 곤란하다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권1호
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• pp.50-57
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• 2015

This study was conducted to investigate the effect of soybean meal (SM) and soluble starch (SS) on biogenic amine production and microbial diversity using in vitro ruminal fermentation. Treatments comprised of incubation of 2 g of mixture (expressed as 10 parts) containing different ratios of SM to SS as: 0:0, 10:0, 7:3, 5:5, 3:7, or 0:10. In vitro ruminal fermentation parameters were determined at 0, 12, 24, and 48 h of incubation while the biogenic amine and microbial diversity were determined at 48 h of incubation. Treatment with highest proportion of SM had higher (p<0.05) gas production than those with higher proportions of SS. Samples with higher proportion of SS resulted in lower pH than those with higher proportion of SM after 48 h of incubation. The largest change in $NH_3$-N concentration from 0 to 48 h was observed on all SM while the smallest was observed on exclusive SS. Similarly, exclusive SS had the lowest $NH_3$-N concentration among all groups after 24 h of incubation. Increasing methane ($CH_4$) concentrations were observed with time, and $CH_4$ concentrations were higher (p<0.05) with greater proportions of SM than SS. Balanced proportion of SM and SS had the highest (p<0.05) total volatile fatty acid (TVFA) while propionate was found highest in higher proportion of SS. Moreover, biogenic amine (BA) was higher (p<0.05) in samples containing greater proportions of SM. Histamines, amine index and total amines were highest in exclusive SM followed in sequence mixtures with increasing proportion of SS (and lowered proportion of SM) at 48 h of incubation. Nine dominant bands were identified by denaturing gradient gel electrophoresis (DGGE) and their identity ranged from 87% to 100% which were mostly isolated from rumen and feces. Bands R2 (uncultured bacterium clone RB-5E1) and R4 (uncultured rumen bacterium clone L7A_C10) bands were found in samples with higher proportions of SM while R3 (uncultured Firmicutes bacterium clone NI_52), R7 (Selenomonas sp. MCB2), R8 (Selenomonas ruminantium gene) and R9 (Selenomonas ruminantium strain LongY6) were found in samples with higher proportions of SS. Different feed ratios affect rumen fermentation in terms of pH, $NH_3$-N, $CH_4$, BA, volatile fatty acid and other metabolite concentrations and microbial diversity. Balanced protein and carbohydrate ratios are needed for rumen fermentation.

• 한국환경과학회지
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• 제23권6호
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• pp.1095-1100
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• 2014

Keratin wastes are generated in excess of million tons per year worldwide and biodegradation of keratin by microorganisms possessing keratinase activity can be used as an alternative tool to prevent environmental pollution. For practical use of keratinase, its physicochemical properties should be investigated in detail. In this study, we investigated characteristics of keratinase produced by Xanthomonas sp. P5 which is isolated from rhizospheric soil of soybean. The level of keratinase produced by the strain P5 increased with time and reached its maximum (10.6 U/ml) at 3 days. The production of soluble protein had the same tendency as the production of keratinase. Optimal temperature and pH of keratinase were $40^{\circ}C-45^{\circ}C$ and pH 9, respectively. The enzyme showed broad temperature and pH stabilities. Thermostability profile showed that the enzyme retained 94.6%-100% of the original activity after 1 h treatment at $10^{\circ}C-40^{\circ}C$. After treatment for 1 h at pH 6-10, 89.2%-100% of the activity was remained. At pH 11, 71.6% of the original activity was retained after 1 h treatment. Although the strain P5 did not degrade human hair, it degraded duck feather and chicken feather. These results indicate that keratinase from Xanthomonas sp. P5 could be not only used to upgrade the nutritional value of feather hydrolysate but also useful in situ biodegradation of feather.

• Asian-Australasian Journal of Animal Sciences
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• 제5권2호
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• pp.217-224
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• 1992

The study was undertaken to determine the effect of dietary magnesium on the eggshell quality and other performance in laying Tsaiya ducks and Leghorn hens. Twenty-five Tsaiya ducks and 25 Leghorn hens were raised in individual cages. The basal diet was mainly consisted of corn starch and isolated soybean protein. At the beginning of the experiments, birds were fed for 10 days with the basal diet supplemented with 500 mg/kg Mg (1070 mg/kg in total by analysis) in order to allow the birds adapting to the new diet. Both Tsaiya ducks and Leghorn hens were then each randomly divided into five groups and each group of five birds were fed with the experimental diets containing 690, 1070, 1690, 2150 or 2380 mg/kg Mg, respectively for 21 days. Eggs were collected in order to measure eggshell quality, Mg and Ca content of the eggshell. At the end of the experiments, blood samples of all birds were taken from their brachial veins for measuring the concentration of Mg and Ca in the plasma. Experimental results appeared that the dietary Mg content did not significantly affect egg production, egg weight, eggshell breaking strength and thickness in both Tsaiya ducks and Leghorn hens. In Tsaiya ducks, however, the plasma Mg concentration was affected by the dietary Mg content, but the plasma Mg almost reached a plateau (4.66 mg/dl) as long as the dietary Mg level was over 1070 mg/kg. In Leghorn hens, the plasma Mg level was significantly increased from 1.66 mg/dl to 4.03 mg/dl when the dietary Mg content in the diet had been increased from 690 mg/kg to 2380 mg/kg, suggesting that the plasma Mg concentration seems to be directly influenced by the Mg absorbed in the intestine. In the Tsaiya ducks, however, the dietary Mg level did not significantly affect the eggshell Mg content (from 0.113% to 0.123%). Whereas, there was a negative correlation between the eggshell thickness and eggshell Mg content (r = -0.50, p<0.01), revealing that the increase in eggshell Mg content probably associated with the impairment of eggshell quality in Tsaiya ducks. In Leghorn hens, however, there was no significant correlation between eggshell quality and eggshell Mg content, although the Mg content in the eggshell was also increased from 0.279% to 0.427% when the dietary Mg had been elevated from 690 mg/kg to 2380 mg/kg.

• 한국식품영양과학회지
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• 제22권2호
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• pp.222-225
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• 1993

축육제품의 실제 열처리 온도범위에서 적용가능한 열확산도 추정식을 제시하고자, 식염 1.5%, 중합인산염 0.2%, lard 및 대두단백질을 임의의 농도로 혼합한 돼지고기를 사용하여 열전달실험을 행하고 열확산도 추정식을 구하였다. 수분함량 49.01~77.55%, 가열온도 80.76~121.03$^{\circ}C$의 범위에서 열확산도는 동일온도에서는 수분함량의 증가에 따라, 동일 수분함량에서는 가열온도가 높아짐에 따라 커졌으며, 각 온도에서의 실측 열확산도는 다음의 식들로 나타낼 수 있었다. $\alpha$p,(80.76$\pm$0.3$^{\circ}C$) =0.0869.$10^{-6}$ .Xw+0.0720.$10^{-6}$ ,(m$^2$.s$^{-1}$, r=0.9230) $\alpha$p, (98.59$\pm$0.3$^{\circ}C$) =0.0849.$10^{-6}$ .Xw+0.0818.$10^{-6}$ , (m$^2$.s$^{-1}$, r=0.9264) $\alpha$p, (121.03$\pm$0.5$^{\circ}C$) =0.0909.$10^{-6}$ .Xw+0.0893.$10^{-6}$ , (m$^2$.s$^{-1}$, r=0.9507)이 식들을 종합한, 임의의 온도에서의 열확산도 추정식은 다음과 같았으며 이로부터 구한 열확산도와 실측치의 차이는 실측치를 기준으로 $\pm$1.7% 이내였다. $\alpha$p=(2.1394+0.5.Xw).$\alpha$w+0.0035.$10^{-6}$ .Xw-0.2785.$10^{-6}$ , (m$^2$.s$^{-1}$).

• 생명과학회지
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• 제27권7호
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• pp.805-811
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• 2017

이전의 논문에서 된장으로부터 섬유소와 지질, 녹말, 그리고 단백질을 포함하는 다양한 유기물을 가수분해하는 세균을 분리한 바 있다. 본 연구에서는 분리균주인 Bacillus subtilis CK-2가 생산하는 각종 가수분해효소의 조효소 특성을 확인하였다. 섬유소분해효소의 경우 적정 수소이온농도는 pH 5.0, 적정온도는 $55^{\circ}C$로 확인되었으며, pH 5.0~10.0과 $20{\sim}50^{\circ}C$의 범위에서 높은 활성을 나타내었다. 섬유소분해효소는 $Co^{2+}$ 이온에 의해 활성이 높아지며, 0.45%(w/v)의 $Co^{2+}$ 이온 농도에서 가장 높은 활성을 보였다. 녹말분해효소의 경우 적정 수소이온농도는 pH 5.0, 적정온도는 $50^{\circ}C$로 확인되었으며, pH 4.0~5.0과 $20{\sim}50^{\circ}C$의 범위에서 높은 활성을 나타내었다. 녹말분해효소는 $Co^{2+}$ 이온에 의해 활성이 높아지며, 0.2%(w/v)의 $Co^{2+}$ 이온 농도에서 가장 높은 활성을 보였다. 단백질분해효소의 경우 적정 수소이온농도는 pH 8.0, 적정온도는 $50^{\circ}C$로 확인되었으며, pH 7.0~8.5과 $20{\sim}50^{\circ}C$의 범위에서 높은 활성을 나타내었다. 섬유소분해효소는 $Mn^{2+}$ 이온에 의해 활성이 높아지며, 0.125%(w/v)의 $Mn^{2+}$ 이온 농도에서 가장 높은 활성을 보였다. 이러한 결과로부터 B. subtilis CK-가 생산하는 가수분해효소를 산업적으로 이용하기 위해서는 효소의 종류에 따라 수소이온농도와 온도, 그리고 금속이온을 적절하게 조절할 필요가 있다는 것을 알 수 있다.