• 한국미생물·생명공학회지
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• 제24권2호
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• pp.178-184
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• 1996

Dryfilm method by using 3M Petrifilm$^{TM}$ has been examined to replace conventional agar method for isolation of microorganisms from foods. The objectives of the present study were to evaluate suitability of dryfilm method as a microbial isolation method and to determine the effect of antimicrobial agent on dryfilm for isolation of microorganisms from foods. Five different foods, milk, ground beef, fishery surimi, Takju and wheat flour were used to isolate the natural microflora in foods and the inoculated Escheri chia coli. Standard method agar (SMA, Difco) and Petrifilm$^{TM}$ aerobic count (PAC, 3M) were used to isolate total microorganisms from foods. Violet red bile agar (VRBA), brilliant green lactose bile (BGLB) broth and Petrifilm$^{TM}$ coliform count (PCC, 3M) were used to isolate coliforms from foods. E. coli broth (EC broth) and Petrifilm$^{TM}$ E. coli count (PEC, 3M) were used to isolate E. coli from foods. Acidified potato dextrose agar (APDA) and Petrifilm$^{TM}$ yeast & mold count (PYMC, 3M) were used to isolate yeasts and molds from foods. Total aerobic plate counts isolated from five different foods by SMA and PAC (3M) were riot significantly different each other at P<0.05 level and were highly correlated each other ($\geq$0.96). Mugwort extract as an antimicrobial agent did not affect microbial enumeratiion of Dryfilm. Significantly higher number of coliform colonies were formed on VRBA than PCC (3M) from ground beef, but they were not significantly different in coliform colonies from milk samples. PCC (3M) and BGLB were not significantly different for enumeration of coliforms in milk and beef samples. Significantly higher number of E. coli were isolated by EC broth than PEC from ground beef, but these were not significontly different for enumeration of E. coli from milk. Yeast and mold counts isolated from Takju and wheat flour by APDA and PYMC (3M) were not significantly different at P<0.05 level. These data indicate that dryfilm method by using 3M Petrifilm$^{TM}$ can be successively used as an alternative to conventional agar method for enumeration of microorganisms in various foods.

• 한국균학회지
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• 제40권1호
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• pp.60-64
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• 2012

한국식품연구원으로부터 분양받은 효모 49종과 곰팡이 34종등 총 83종의 진균류들의 PD broth 배양 농축물들의 생리 기능성을 측정 하였다. 효모 배양 농축물중에서는 Saccharomyces cerevisiae Y277-3 과 Saccharomyces cerevisiae Y157-1 의 PD broth 배양 농축물들의 tyrosinase 저해활성이 각각 42.7%와 41.2%로 생리기능성중 제일 높은 활성을 보였다. 또한 곰팡이 배양 농축물에서는 Aspergillus oryzae CN20-3-1-4 배양 농축물의 항산화 활성이 15.8%로 가장 높았으나 대체로 낮은 생리기능성을 보였다. 시험 진균류들의 생리기능성중 가장 높았던 Saccharomyces cerevisiae Y277-3 의 세포내 tyrosinase 저해물질은 이 효모를 PD broth 에 접종하여 $30^{\circ}C$에서 24시간 배양 하였을때 가장 많이 생산 되었다.

• 한국축산식품학회지
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• 제22권1호
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• pp.44-49
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• 2002

구연산과 아염소산나트(NaClO$_2$)이 0:100, 25:75, 50:50, 75:25와 100:0(w:w)의 비율로 된 혼합물이 육계 넓적다리 표면에 존재하는 호기성 미생물 증식에 미치는 영향을 조사하였다. 접종된 nutrient broth에 각각의 혼합물을 0, 100, 200과 500 ppm(w/v) 넣어 4~5$^{\circ}C$에서 배양한 후 흡광도와 호기성 미생물 수를 측정하였다. 선택된 혼합물 용액에 넓적다리를 침지한 후 냉장 저장(4~5$^{\circ}C$)하여 호기성 미생물 수를 측정하였다. 구연산과 아염소산나트륨의 혼합물을 첨가한 nutrient broth 흡광도는 100:0의 200 및 500 ppm(w/v)의 처리 직후를 제외하고 저장 기간 동안 모든 비율 및 농도에서 대조구보다 낮은 수치를 나타내었다 (p<0.05). 그리고 첨가물의 농도가 높을수록 흡광도는 낮은 경향을 나타내었다.

• 동아시아식생활학회지
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• 제22권4호
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• pp.558-565
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• 2012

The objective of this study was to develop a predictive growth model for Bacillus cereus in nutrient broth and validate the developed growth model in blanched vegetables. After inoculating B. cereus into nutrient broth, growth of B. cereus was investigated at 13, 17, 24, 30 and $35^{\circ}C$. Lag time (LT) decreased while specific growth rate (SGR) increased with an increase in storage temperature. Growth of B. cereus was not observed at temperatures lower than $12^{\circ}C$. Secondary growth models were developed to describe primary model parameters, including LT and SGR. Model performance was evaluated based on bias factor ($B_f$) and accuracy factor ($A_f$). In addition, we inoculated B. cereus into blanched vegetables stored at 13, 24, $35^{\circ}C$ and observed the growth kinetics of B. cereus in five different blanched vegetables. Growth of B. cereus was most delayed on Doraji at $13^{\circ}C$ and was not observed on Gosari at $13^{\circ}C$. Growth of B. cereus at $35^{\circ}C$ was significantly (p<0.05) slower on Gosari than on other blanched vegetables. The developed secondary LT model for broth in this study was suitable to predict growth of B. cereus on Doraji and Gosari, whereas the SGR model was only suitable for predicting the growth of B. cereus on mung bean sprout.

• Mycobiology
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• 제36권1호
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• pp.13-18
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• 2008

Eight distinct bacteria were isolated form diseased mycelia of the edible mushroom, Pleurotus eryngii. 16S rDNA sequence analysis showed that the isolates belonged to a variety of bacterial genera including Bacillus (LBS5), Enterobacter (LBS1), Sphingomonas (LBS8 and LBS10), Staphylococcus (LBS3, LBS4 and LBS9) and Moraxella (LBS6). Among them, 4 bacterial isolates including LBS1, LBS4, LBS5, and LBS9 evidenced growth inhibitory activity on the mushroom mycelia. The inhibitory activity on the growth of the mushroom fruiting bodies was evaluated by the treatment of the bacterial culture broth or the heat-treated cell-free supernatant of the broth. The treatment of the culture broths or the cell-free supernatants of LBS4 or LBS9 completely inhibited the formation of the fruiting body, thereby suggesting that the inhibitory agent is a heat-stable compound. In the case of LBS5, only the bacterial cell-containing culture broth was capable of inhibiting the formation of the fruiting body, whereas the cell-free supernatant did not, which suggests that an inhibitory agent generated by LBS5 is a protein or a heat-labile chemical compound, potentially a fungal cell wall-degrading enzyme. The culture broth of LBS1 was not inhibitory. However, its cell-free supernatant was capable of inhibiting the formation of fruiting bodies. This indicates that LBS1 may produce an inhibitory heat-stable chemical compound which is readily degraded by its own secreted enzyme.

• 한국식품과학회지
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• 제26권5호
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• pp.627-632
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• 1994

Disk method에 의한 예비 실험 결과 Listeria monocytogenes ATCC 19111, 19112, 19113, 19114 및 15313에 대하여 성장억제 효과가 있었던 방기 및 감초의 75% ethanol 추출물을 농도별로 tryptic soy broth에 첨가하고 각 균주를 증식, 그 저해 정도를 비교하였다. 방기는 실험대상 균주 중 L. monocytogenes ATCC 19111 및 19114에 부분적으로 효과가 있었고 첨가 농도에 따라 그 증식 저해 정도는 비례하였다. 감초 추출물은 실험 대상 5균주 모두에 강한 항균성을 보였으며 대부분 100ppm 첨가에서도 $12{\sim}48$시간 동안 완전히 증식을 억제 하였으며 500ppm 첨가 수준에서는 모든 균에 대하여 완전 증식 억제 현상을 보여 우수한 증식 억제제로 확인되었다. 특히 L. monocytogenes ATCC 19113의 경우 100ppm 첨가에서도 48시간 까지 완전 성장 억제가 가능하였다.

• 한국환경과학회지
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• 제12권10호
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• pp.1079-1084
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• 2003

This study was carried out to check changes of components in the slaughter waste by the bacteria isolated from slaughter wastes from Gyungnam Province from May to June 2000, and to find usefu] organism for treatment of the waste. Bacteria used in this study were Aeromonas hydrophila, as the dominant of the waste. Optimum conditions for bacterial culture were obtained as the temperature of 35$^{\circ}C$, pH 6.5, and shaking of 120 rpm in nutrient broth. The mean values of dissolved oxygen was 4.14 mg/1; biochemical oxygen demand, 1731.21 mg/1; ratio of BOD/COD, 0.53-0.64; ratio of T-P/T-N, 1.0-1.41; and viable counts of the waste, 5.47${\times}$10$\^$7/ CFU. Little change in total nitrogen observed by 36 hr of the culture. The largest amount of increasing NH$_4$$\^$+/-N was observed in the sample that 10% of the waste added in nutrient broth with A. hydrophila showing the value of 29.19 mg/l at the beginning to 570.36 mg/1 by 36 hr of culture. However, the highest increasing ratio between initial amount and finals at 36 hr of culture showed as 41.6 times when 3% of the waste added. NO$_3$ -N was decreased showing the value of 71.27 mg/1 to 32.14 mg/1 by 24 hr of culture with the organism when 10% of the waste added in nutrient broth. Total phosphorus was decreased showing the value from 188.74 mg/1 to 101.41 mg/1 after 12 hr of culture with the organism when 5% of the waste added in nutrient broth, while T-P was decreased gradually by 24 hr of culture from 193.8 to 101.4 mg/1 when 10% of the waste added.

• 대한소아치과학회지
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• 제25권3호
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• pp.619-626
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• 1998

The critical etiologic factor in the development of dental caries is dental plaque. The main component of dental plaque is the mutan produced by Streptococcus mutans. The following results were obtained by using blue mutan to assess the factors affecting the mutan-digesting activity of Micromonospora aurantiaca isolated from oral cavity. Micromonospora aurantiaca digested more blue mutan in the minimal essential broth at pH 7.0 than at pH 5.5 or 8.5, and at $37^{\circ}C$ than at $32^{\circ}C\;or\;42^{\circ}C$. Blue mutan was similarly digested at the range of 1mM to 16mM of $CaCl_2$ and 0.1mM to 6.4 mM of $MgCl_2$, while being significantly digested at the concentration of 2.5mM of KCl. When the concentration of glucose was decreased in the minimal essential broth, the digestion of blue mutan was increased. When the culture supernatant of Micromonospora aurantiaca in the RL broth with 1% glucose or 0.5% mutan was mixed with 2 ${\times}$ BHIYS broth containing 0.5% yeast extract and 10% sucrose, the formation of artificial plaque on the orthodontic wires by Streptococcus mutans was inhibited(p<0.05). These results indicated that the production of mutanase was identified in the culture supernatant of Micromonospora aurantiaca, suppressing the formation of artificial plaque by Streptococcus mutans.

• 미생물학회지
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• 제45권4호
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• pp.416-418
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• 2009

번데기동충하초의 간독성 회복 효과를 HaM/ICR 계열의 흰쥐를 이용하여 검정하였다. 벤조피렌 복강주사시, 혈중의 aspartate aminotransferase (AST) 및 alanine aminotransferase (ALT)의 효소활성과 간조직의 lipid peroxide (LPO) 농도는 대조군과 비교시 급격히 증가하여 간독성을 유발하였다. 그러나, 벤조피렌 대조군과 비교시, 번데기 동충하초 배양액의 경구 투여시 AST와 ALT의 효소활성 및 LPO 농도는 감소하였으며, 벤조피렌에 유도된 간 조직의 glutathione 농도 및 glutathione S-transferase 효소활성은 증가하여 간독성을 회복하였다. 실험결과는 번데기 동충하초 균사체 배양액이 벤조피렌 유발 간독성에 대해 회복 효과가 있음을 보여준다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권2호
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• pp.128-135
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• 2005

Mixed-mode hydrophobic/ionic matrices exhibit a salt-tolerant property for adsorbing target protein from high-ionic strength feedstock, which allows the application of undiluted feedstock via an expanded bed process. In the present work, a new type of mixed-mode adsorbent designed for expanded bed adsorption, Fastline $PRO^{\circledR}$, was challenged for the capture of nattokinase from the high ionic fermentation broth of Bacillus subtilis. Two important factors, pH and ion concentration, were investigated with regard to the performance of nattokinase ad-sorption. Under initial fermentation broth conditions (pH 6.6 and conductivity of 10 mS/cm) the adsorption capacity of nattokinase with Fastline PRO was high, with a maximum capacity of 5,350 U/mL adsorbent. The elution behaviors were investigated using packed bed adsorption experiments, which demonstrated that the effective desorption of nattokinase could be achieved by effecting a pH of 9.5. The biomass pulse response experiments were carried out in order to evaluate the biomass/adsorbent interactions between Bacillus subtilis cells and Fastline PRO, and to demonstrate a stable expanded bed in the feedstock containing Bacillus subtilis cells. Finally, an EBA process, utilizing mixed-mode Fastline PRO adsorbent, was optimized to capture nattokinase directly from the fermentation broth. The purification factor reached 12.3, thereby demonstrating the advantages of the mixed-mode EBA in enzyme separation.