• 한국식품위생안전성학회지
• /
• 제14권3호
• /
• pp.259-264
• /
• 1999

Xylooligosaccharide의 세균에 대한 돌연변이 유발성을 검색하기 위하여 Salmonella typhimurium의 히스티딘 요구성균주 TA100, TA1535, TA98 및 TA1537의 4개 균주와 대장균 Escherichia coli의 트립토판 요구성 균주인 WP2 uvrA를 이용해 복귀돌연변이 시험을 실시하였다. 시험 물질은 증류수에 용해하여 처리하였으며, 대사 활성계 미적용 및 적용하에 $5000\;\mu\textrm{g}/plate$를 최고농도로 하고 공비 2로서 5단계 농도군(313, 625, 1250, 2500 및 $5000\;\mu\textrm{g}/plate$)과 음성 및 양성 대조군으로 시험군을 구성해 본 시험을 실시하였다. 시험 결과 시험물질을 처리한 모든 농도군에서 복귀돌연변이 집락 수는 음성대조군과 비슷한 정도로 관찰되었다. 이상의 결과에서, xylooligosaccharide는 본 시험 조건 하에 사용한 균주들에 복귀돌연변이를 유발하지 않는 것으로 사료되었다.

• 한국식품조리과학회지
• /
• 제26권6호
• /
• pp.848-852
• /
• 2010

This study investigated the antibacterial activities of extracts and fractions of Sasa borealis against eight bacteria (Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Psedomonas aerginosa, Salmonella choleraesuis, Serratia marcescens and Vibrio vulnificus) by broth dilution assay. Using survival curves, the kinetics of bacterial inactivation upon exposure to the extracts and fractions were followed for 24 h. In this same manner, MIC (minimum inhibitory concentration) values were determined by broth microdilution assay and then confirmed to be the extract concentrations that inhibited bacterial growth. Sasa borealis extracts showed antibacterial activities against all tested bacteria. In particular, all tested fractions of Sasa borealis had stronger activities than 70% ethanol extract. MIC of Sasa borealis extract was determined to be 5 mg/mL against Salmonella choleraesuis. All fractions of Sasa borealis extract had extremely strong antibacterial activities. MIC of fractions were determined to be 0.03~2.5 mg/mL. These results suggest that the extracts and fractions of Sasa borealis effectively inhibited bacterial growth and thus are useful as natural antibacterial agents.

• 식품보건융합연구
• /
• 제6권5호
• /
• pp.1-10
• /
• 2020

Cellulitis in broiler chickens is one of the economically important problems that facing the broiler industry due to the presence of the lesion leads to condemnation of part of /or the entire carcasses. Broiler with cellulitis lesions showed lower body weight. Cellulitis was recorded on different body regions including the head, dorsum, thighs, breast, legs, and abdomen. Cellulitis results from the invasion of subcutaneous (s.c.) tissues by bacteria through disruption of skin integrity. Lesions revealed the existence of the characteristic s.c colored exudate varies from yellowish to green, which were either serosanguineous, fibrinous s.c exudate yellowish, greenish or suppurative. Many bacterial isolates including E. coli, Staphylococci, Clostridia, Aeromonas spp., Enterobacter spp., Proteus mirabilis, P. aeruginosa, and Streptococci were isolated from the lesion. Chickens exposed to immunosuppression proved to have a greater probability of developing cellulitis. The condition was experimentally induced by s.c inoculation of 25-day-old broiler chickens with E. coli, S. aureus and clostridia. Usually, bacterial isolates were multidrug-resistant. The usage of Bifidobacterium bifidum or antibiotic with avoiding immunosuppression can reduce lesion and condemnation rate resulted from cellulitis. The objective of this review is to collect different literature written about cellulitis to be available to students, researchers, and veterinarians in poultry practical.

• Journal of Microbiology and Biotechnology
• /
• 제31권3호
• /
• pp.429-438
• /
• 2021

Bacterial cellulose (BC) is widely used in the food industry for products such as nata de coco. The mechanical properties of BC hydrogels, including stiffness and viscoelasticity, are determined by the hydrated fibril network. Generally, Komagataeibacter bacteria produce gluconic acids in a glucose medium, which may affect the pH, structure and mechanical properties of BC. In this work, the effect of pH buffer on the yields of Komagataeibacter hansenii strain ATCC 53582 was studied. The bacterium in a phosphate and phthalate buffer with low ionic strength produced a good BC yield (5.16 and 4.63 g/l respectively), but there was a substantial reduction in pH due to the accumulation of gluconic acid. However, the addition of gluconic acid enhanced the polymer density and mechanical properties of BC hydrogels. The effect was similar to that of the bacteria using glycerol in another carbon metabolism circuit, which provided good pH stability and a higher conversion rate of carbon. This study may broaden the understanding of how carbon sources affect BC biosynthesis.

• Journal of Digestive Cancer Research
• /
• 제10권1호
• /
• pp.31-38
• /
• 2022

Ulcerative colitis (UC) exhibits chronic intestinal inflammatory conditions with cycles of relapse and remission. The incidence is rapidly growing in Asian countries including South Korea possibly due to changes in lifestyles. Although the etiology of inflammatory bowel disease is inconclusive, gut microbiota composition is considered a critical factor involved in the pathogenesis of UC. The overgrowth of pathogenic bacteria evokes hyper-immune responses in gut epithelium causing tissue inflammation and damage. Also, failure to regulate gut epithelium integrity due to chronic inflammation and mucus depletion accelerates bacterial translocation aggravating immune dysregulation. Gut microbiota composition responds to the diet in a very rapid manner. Epidemiological studies have indicated that the risk of UC is associated with low plant foods/high animal foods consumption. Several bacterial strains consistently found depleted in UC patients use plant food-originated dietary fiber producing short chain fatty acids to maintain epithelial integrity. These bacteria also use mucus layer mucin to keep gut microbiota diversity. These studies partly explain the association between dietary modification of gut microbiota in UC development. Further human intervention trials are required to allow the use of specific bacterial strains in the management of UC.

• 한국식품영양과학회지
• /
• 제31권3호
• /
• pp.433-437
• /
• 2002

본 연구는 손착유 모유와 breast-pump에 의한 기계착유모유 중의 총균수와 대장균수를 검사하고 또한 냉장 및 실온보존에 따른 모유(초유, 성숙유)와 환원조제분유의 저장성을 파악하고자 시험하였다. 시험 결과 breast-pump로 수집한 모유 중의 총균수는 2.02$\times$$10^4$CFU/mL로 손착유에 의한 총균수 1.06$\times$$10^4$ CFU/mL보다 약 2배 가량 많이 나타났으며 특히 대장균의 경우, 손착유에 의한 감염율이 12.9%인 반면 breast-pump로 수집한 모유의 감염율은 19.5%로 높게 나타났다. 또한 모유와 환원조제분유를 냉장(4$^{\circ}C$) 및 실온(2$0^{\circ}C$, 3$0^{\circ}C$)상태에서 보존하면서 총균수와 대장균수의 변화를 시험한 결과, 4$^{\circ}C$에서 대장균수의 변화는 10일 동안 뚜렷한 변화를 보이지 않았으며 총균수는 지속적으로 약간 감소하는 경향을 나타냈다. 2$0^{\circ}C$에서 총균수의 변화는 모유 성숙유와 모유 초유에서 뚜렷한 증가 추세를 보이지 않았으나 대장균의 경우 지속적인 증가 추세를 보였으며, 특히 환원조제분유에서 대장균수는 12시간 이후 급속히 증가하는 경향을 나타냈다. 3$0^{\circ}C$에서 총균수의 변화는 모유 성숙유의 경우 12시간 이후 급속히 증가하는 경향을 보였으나 모유 초유의 경우 뚜렷한 증가 추세를 보여주지 않았다. 반면에 환원조제분유는 6시간 이후 급속히 증가하는 추세를 나타냈다.

• 한국식품과학회지
• /
• 제30권2호
• /
• pp.319-323
• /
• 1998

치자의 황색소를 L. plantalium, V. vulinficus, P. aeruginosa, S. mutans, B. subtilis, S. epidermidis, S. typhimurium, S. aureus 등 8종의 균주의 배지에 첨가하고 배양하면 청녹색계 색소로 변환된다. 미생물에 의해 변환된 색소의 분광학적 성질을 경시적으로 추적하면 색소의 변환형태는 3군으로 나뉘어지며, 색차계로 측정된 ${\Delta}E$ 값의 변환형태도 그러하였다. 청녹색계색소로의 변환속도는 균주에 따라 차이를 보였는데 8종의 미생물중 S. epidermidis는 가장 빨라 배양 16시간에 색소변환이 완성되었다. 치자황색소와 변환된색소는 $H_2O-MeOH$ 용매계에 의한 Amberlite XAD-4 column chromatography에 의해 완전히 분리되었으며, 광과 열에 대한 저장안정성은 치자황색소보다 변환된 색소가 보다 안정함을 나타냈다.

• 환경위생공학
• /
• 제14권4호
• /
• pp.9-20
• /
• 1999

This paper studies regarding the problems of transmitting disease through food and its prevention in terms of current problematic food poisoning and the transfer of bacterial disease while providing lunch for school children. As the problems of school lunch program, the number of food poisoning and of the transfer of bacterial disease is highly increasing because of the shortcomings of systematic safety management toward food and of the lack of meal supplier's awareness about sanitation.For the prevention the following suggestions are provided:1. It is necessary to shift from the system of meal supply for nutrition to that of meal supply for health. 2. A system that offers a responsibility for nutrition to that of meal supply to a person in charge of hygienist, or a cook, including the a nutritionist, is needed. 3. It is necessary to gain the help from the department of sanitation in city or country for the sanitation guidance and inspection of school meal supply, not to totally rely on the local ministry of education. 4. A manager or employees related to school/group meal supply need to get education constantly on sanitation and public information. 5. For the long term, a systematic sanitary management needs to be accomplished by introducing HACCP system.

• Journal of Microbiology and Biotechnology
• /
• 제23권3호
• /
• pp.357-363
• /
• 2013

The identification of bacteriophage proteins on the surface of Lactobacillus rhamnosus Pen was performed by LC-MS/MS analysis. Among the identified proteins, we found a phage-derived major tail protein, two major head proteins, a portal protein, and a host specificity protein. Electron microscopy of a cell surface extract revealed the presence of phage particles in the analyzed samples. The partial sequence of genes encoding the major tail protein for all tested L. rhamnosus strains was determined with specific primers designed in this study. Next, RT-PCR analysis allowed detection of the expression of the major tail protein gene in L. rhamnosus strain Pen at all stages of bacterial growth. The transcription of genes encoding the major tail protein was also proved for other L. rhamnosus strains used in this study. The present work demonstrates the spontanous release of prophage-encoded particles by a commercial probiotic L. rhamnosus strain, which did not significantly affect the bacterial growth of the analyzed strain.

• Mycobiology
• /
• 제47권2호
• /
• pp.250-255
• /
• 2019

In the present study, we aimed to determine the cause of surface film formation in three rice vinegars fermented using the traditional static fermentation method. The pH and total acidity of vinegar were 3.0-3.3 and 3.0-8.7%, respectively, and acetic acid was the predominant organic acid present. Colonies showing a clear halo on GYC medium were isolated from the surface film of all vinegars. Via 16S rDNA sequencing, all of the isolates were identified as Acetobacter pasteurianus. Furthermore, field-emission scanning electron microscopy analysis showed that the bacterial cells had a rough surface, were rod-shaped, and were ${\sim}1{\times}2{\mu}m$ in size. Interestingly, cells of the isolate from one of the vinegars were surrounded with an extremely fine threadlike structure. Thus, our results suggest that formation of the surface film in rice vinegar was attributable not to external contamination, to the production of bacterial cellulose by A. pasteurianus to withstand the high concentrations of acetic acid generated during fermentation. However, because of the formation of a surface film in vinegar is undesirable from an industrial perspective, further studies should focus on devising a modified fermentation process to prevent surface film formation and consequent quality degradation.