• Journal of Microbiology and Biotechnology
• /
• 제27권1호
• /
• pp.130-140
• /
• 2017

It is vital to understand the changing characteristics of interphase microbial communities and interspecies synergism during the fermentation of Chinese liquors. In this study, microbial communities in the three indispensable phases (pit mud, zaopei, and huangshui) of Luzhou-flavored liquor manufacturing pits and their shifts during cellars use were first investigated by polyphasic culture-independent approaches. The archaeal and eubacterial communities in the three phases were quantitatively assessed by combined phospholipid ether lipids/phospholipid fatty acid analysis and fluorescence in situ hybridization. In addition, qualitative information regarding the microbial community was analyzed by PCR-denaturing gradient gel electrophoresis. Results suggested that the interphase microbial community profiles were quite different, and the proportions of specific microbial groups evolved gradually. Anaerobic bacteria and gram-positive bacteria were dominant and their numbers were higher in pit mud ($10^9$ cells/g) than in huangshui ($10^7$ cells/ml) and zaopei ($10^7$ cells/g). Hydrogenotrophic methanogenic archaea were the dominant archaea, and their proportions were virtually unchanged in pit mud (around 65%), whereas they first increased and then decreased in zaopei (59%-82%-47%) and increased with pit age in huangshui (82%-92%). Interactions between microbial communities, especially between eubacteria and methanogens, played a key role in the formation of favorable niches for liquor fermentation. Furthermore, daqu (an essential saccharifying and fermentative agent) and metabolic regulation parameters greatly affected the microbial community.

• 대한소아치과학회지
• /
• 제34권4호
• /
• pp.632-638
• /
• 2007

Xylitol 껌의 mutans streptococci(MS)에 대한 항균효과를 평가하기 위하여 6세${\sim}$11세 사이의 혼합치열기 어린이 62명을 선정하였다. 4개월 동안 1개의 xylitol 껌을 하루 3회 씹는군, 2개의 xylitol 껌을 하루 3회 씹는 군과 xylitol 껌을 씹지 않는 대조군으로 나누어 하루 3번 식후 최소 5분간 껌을 씹게 한 후 1개월 간격으로 자극성타액을 채취하여 선택배지(mitis salivarius kanamicin bacitracin agar)에 배양한 후 MS 군락 수의 감소를 평가하였다. 1회 1개의 xylitol 껌을 씹는 군에서는 MS의 감소를 보이지 않았고, 1회 2개의 xylitol 껌을 씹는 군에서 4개월째 MS의 유의한 감소를 보였다(P < 0.05). 따라서 혼합치열기 어린이의 경우 하루 3회, 총 10g 정도의 xylitol을 4개월 이상 꾸준히 사용하였을 경우 치아우식증에 대한 예방효과가 있을 것으로 사료된다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권4호
• /
• pp.1261-1266
• /
• 2012

Introduction: HPV has been found repeatedly in esophageal squamous cell carcinoma (ESCC) tissues. However, reported detection rates of HPV DNA in these tumors have varied markedly. Differences in detection methods, sample types, and geographic regions of sample origin have been suggested as potential causes of variation. We have reported that infection of HPV DNA in ESCC tumors depends on anatomical sites of esophagus of the patients from Mazandaran, north of Iran. Materials and Methods: HPV DNA was examined in 46 upper, 69 middle and 62 lower third anatomical sites of esophageal squamous cell carcinoma specimens collected from Mazandaran province in north Iran, near the Caspian Littoral as a region with high incidence of ESCC. HPV L1 DNA was detected using Qualitative Real time PCR and MY09/MY11 primers. Results: 28.3% of upper, 29% of middle and 25.8% of lower third of ESCC samples were positive for HPV DNA. 13.6% for males and 14.1% for females were HPV positive in all samples. Conclusions: HPV infection is about one third of ESCC in this area. Findings in this study increase the possibility that HPV is involved in esophageal carcinogenesis. Further investigation with a larger sample size is necessary.

• Journal of Microbiology and Biotechnology
• /
• 제18권10호
• /
• pp.1722-1728
• /
• 2008

The natural course of chronic hepatitis B (CH-B) virus infection is reportedly variable, and the long-term outcomes in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B infection are distinct from HBeAg-positive chronic hepatitis. However, the molecular virological factors that contribute to the progression of liver disease in the south Indian setting remain largely unclear. We prospectively studied 679 consecutive patients for HBsAg, HBeAg, anti-HBe, and HBV DNA by qualitative PCR. Randomly selected samples were subjected to bidirectional sequencing to reveal core/precore variants. Of the total 679 chronic HBV cases investigated, 23% (154/679) were replicative HBV carriers. Furthermore, amongst the 560 HBV DNA samples analyzed, 26% (146/560) were viremic. Among the 154 HBeAg positive cases, HBV DNA was positive in 118 cases (77%), significantly (p<0.001) higher than the anti-HBe positive (7%) (28/406) cases. Significant increase in liver disease (p<0.01) with ALT enzyme elevation (p<0.001) was observed in both HBe and anti-HBe viremic cases. Interestingly, low frequencies of mutations were seen in the precore region of the HBV strains studied. HBV precore and core promoter variants were less often detected in subjects with "e" negative chronic HBV infection and, therefore, may not have a prognostic role in determining liver disease sequelae in this part of tropical India.

• 한국환경보건학회지
• /
• 제37권5호
• /
• pp.376-386
• /
• 2011

Objectives: The aim of this study was to evaluate the microbial hazards posed by food utensils and fixtures in food service operations at selected middle and high schools located in Seoul, Korea. Methods: We collected 200 samples of utensils and fixtures including cups, spoons/chopsticks, food trays and tables from five different schools in Seoul. Target microorganisms of this study were divided into two groups: total bacterial count and total coliform as indicators of microbial contamination and Bacillus cereus and Staphylococcus aureus as pathogens of food poisoning. We used selective media to quantify microbial concentration and 16S rRNA PCR assay for qualitative analysis. In addition, intensive interviews with nutritionists were conducted and observations were made to identify factors that may affect microbial contamination. Logistic regression analysis was employed to examine the relationship between the microbial concentration and operation characteristics of each operation. Results: The level of microbial concentration in school B and C were significantly lower than in school A, D and E (p<0.05). Some samples from school A, D and E showed over 3.4 log CFU/100 $cm^2$ (total bacterial count) and 1.0 log CFU/100 $cm^2$ (total coliform), which requires immediate hygienic action. The number of customers per staff member, periodicity of hygiene education for staff and daily operation time of sterilizers were also found to be important factors related with the microbial contamination of food service operations. Conclusions: These results suggested that not only a HACCP (Hazard Analysis and Critical Control Point) approach, but also efforts to assess internal risk factors within operations be needed to reduce the microbial contamination of food utensils and fixtures. This study is expected to provide preliminary data for assessing microbial hazards in food service operations.

• 미생물학회지
• /
• 제45권2호
• /
• pp.215-221
• /
• 2009

대장균에서 비천연 아미노산을 단백질 생합성시 특정 위치에 삽입하는 방법의 하나로 amber suppressor tRNA와 여기에 비천연 아미노산을 특이적으로 결합할 수 있는 변형된 aminoacyl-tRNA synthetase 쌍을 이용한다. 이러한 기술의 개발을 위해 필요한 여러 요소 중 하나는 이러한 시스템이 대장균에서 얼마나 잘 작동하는지를 확인할 수 있는 in vivo 보고시스템을 설정하는 것이다. 본 논문에서는 $\beta$-galactosidase 유전자의 N-말단에 amber 코돈을 삽입한 보고유전자를 제작하였으며, 이를 대장균(DH10B)의 chromosomal DNA에 삽입하여 DH10B(Tn:lacZam) 균주를 개발하였다. Genomic PCR과 Southern blot 분석을 통하여 lacZ amber 유전자가 대장균의 염색체에 삽입된 것을 확인하였으며, DH10B(Tn:lacZam)은 amber suppression을 유도할 수 있는 벡터가 형질 전환될 경우만 $\beta$-galactosidase 활성을 나타냈다. DH10B(Tn:lacZam)에 효모균의 amber suppressor $tRNA^{Tyr}$와 Tyrosyl-tRNA synthetase 쌍을 동시에 발현하는 벡터를 형질전환하였을 때, amber suppression에 의해서 $\beta$-galactosidase 활성이 나타났다. 하지만 이 활성은 대장균의 amber suppressor $tRNA^{Gln}$를 발현하는 pSupE2를 형질전환하였을 때와 비교 하여 매우 낮은 $\beta$-galactosidase 활성을 나타냈다. 이러한 결과는 DH10B(Tn:lacZam) 균주가 $\beta$-galactosidase 활성을 통하여 정성 및 정량적으로 in vivo amber suppression 활성을 비교 분석할 수 있는 특성을 가졌음을 나타낸다.