• KSBB Journal
• /
• 제29권1호
• /
• pp.72-80
• /
• 2014

CW-4Y was identified as Stenotrophomonas sp. by morphological and physiological characteristics, and phylogenetic analysis of its 16S rDNA gene sequence. Nitrogen removal by CW-4Y was analyzed in relation to the ammonium concentration, presence of organic carbon, carbon source, and carbon-to-nitrogen ratio (C/N). Stenotrophomonas CW-4Y has heterotrophic nitrification and aerobic denitrification abilities. Stenotrophomonas CW-4Y utilized only glucose as carbon sources, and heterotrophic nitrification and aerobic denitrification were observed regardless of the type of nitrogen source. The maximum ammonium removal rate of CW-4Y was 80 $mg-N{\cdot}L^{-1}{\cdot}d^{-1}$ and its denitrification rate of 192 $mg-N{\cdot}L^{-1}{\cdot}d^{-1}$ at $NO_3{^-}-N$ (about 280 ppm) in shake culture experiments at a C/N ratio of about 15 was about 30 times higher than those of other bacteria with the same ability.

• Journal of Microbiology and Biotechnology
• /
• 제15권5호
• /
• pp.992-1000
• /
• 2005

Campylobacter is one of the emerging foodborne pathogens, and its worldwide incidence rate is extremely high. This study was undertaken to isolate and identify Campylobacter strains from chicken carcasses in the local markets, and analyze their characteristics regarding oxygen tolerance. They were isolated after aerobic enrichment and identified by biochemical, physiological, and morphological characteristics, PCR, and 16S rDNA sequencing. Their oxygen tolerances were analyzed in terms of the cell surface hydrophobicity, cell fatty acid composition, and oxidoreductase. Five strains of C. jejuni were isolated and identified from 61 isolates from 50 chickens. Among them, C. jejuni IC21 grew well in Brucella broth and commercial milk under aerobic condition. However, in the aerobic exposure, the cell surface hydrophobicity of C. jejuni IC21 was almost the same as the other isolates, even though its morphology changed from the spiral-bacilli form into the coccoid form. Fatty acid analyses showed that all Campylobacter strains had a high composition of $C_{19:1}$, cyclopropane fatty acid, and that the amount of the other fatty acids were very similar between them. Interestingly, however, only oxidoreductase activities of C. jejuni IC21 increased highly under aerobic exposure even though its activities were almost the same as the other C. jejuni strains just after microaerobic culture. It had 11.8 times higher catalase activity, 4.4 times higher for SOD, and 2.0 times higher for NADH oxidase activities. Therefore, in the case of the aero-adaptive C. jejuni IC21, expression of oxidoreductase significantly increased under oxidative stressed condition, which might allow it to survive for a longer time and grow on food under aerobic exposure. Such new strain might be one of the explanations for the increase of campylobacteriosis.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.544-548
• /
• 2000

수계로부터 anthraquinone계 염료인 Remazol brilliant blue R를 분해 ${\cdot}$ 자화하는 균주를 분리하여 Strain RBB로 명명하고 성장특성을 조사하였다. 최적 배양온도와 pH는 $35^{\circ}C$, 9.0으로 나타났다. 진탕배양의 경우가 정치배양의 경우보다 미생물 성장속도가 현저히 상승하였다.

• 한국물환경학회지
• /
• 제36권2호
• /
• pp.148-152
• /
• 2020

The quantitative accuracy of dry rehydratable film method was compared with the standard culture method to analyze the applicability of dry rehydratable film in the total aerobic bacteria test for water. The materials used in this study were 500 cases of water and were tested according to the Korean official test method for drinking water. The mean value of the total aerobic bacteria in plate count agar(PCA) and MC-Media Pad AC(MAC) were 2.6 ± 1.1 Log cfu/mL and 2.6 ± 1.2 Log cfu/mL. The p value and correlation coefficient(R²) were 0.933 and 0.9985 between the PCA and MAC, respectively, indicating no significant difference and very high correlation. According to the water types, the p value and R² were 0.887 and 0.9911 in the PCA and MAC. In the purified water, the p value was 0.973 and R² was 0.9934 in the PCA and MAC of other water. In each type of water, there were no significant differences between the PCA and MAC, and the correlation was very high. Thus, it is suggested that the MAC would be available for total aerobic bacteria test for water.

• 유기물자원화
• /
• 제8권4호
• /
• pp.147-152
• /
• 2000

남은 음식물을 기질로 생균효모사료를 만들기 위해 Kluyveromyces marxianus 효모의 호기적 액상발효가 $35^{\circ}C$에서 시도되었다. 먼저 액상으로 시료를 충분히 마쇄시킨 시료의 효모 생균수를 증가시키기 위한 적정발효조건이 진탕배양을 통해 연구되었다. 시료로 사용된 남은 음식물의 고형분 함량을 수분첨가로 5%, 10%와 15%로 다르게 조정하여 발효시킨 결과 고형분 함량 10%에서 생균수가 가장 높은 것으로 나타났다. 효모의 생균농도를 증가시키기 위하여 Aspersillus oryzae를 2리터용 jar fermenter를 이용하여 혼합배양한 결과 증식속도를 증가시켜 주었으나 최고 생균수는 $3.5{\times}10^9/ml$로서 단독 배양시보다 근소하게 높은 결과를 보여주었다.

• 생명과학회지
• /
• 제13권4호
• /
• pp.511-515
• /
• 2003

대표적인 azo계 반응성 염료인 Remazol Black B에 대한 탈색능이 우수한 신규 백색부후균인 Phanerochaete sp. EJ-31L의 탈색 특성을 평가해 보았다. 보조 탄소원 농도, 질소원, pH 등의 배양조건이 염료 탈색율에 미치는 영향을 분석한 결과, 3%(w/v)의 sucrore, 0.05%(w/v)의 $(NH_4)_2SO_4$를 첨가한 배지에서 pH 6.5의 조건에서 탈색능이 우수하였다. 혐기적 조건에서는 호기적 조건 대비 27% 수준의 탈색 효율을 보였으며, 진탕배양에서의 탈색율이 정치배양 대비 2배이상 높아 Phanerochaete sp. EJ-31L은 호기적 조건에서 탈색능이 우수함을 알 수 있었다. 초기 Remazol Black B 농도 50 ppm에 대한 회분식 처리시 약 95% 이상의 탈색율을 보여 향후 azo계 염료 처리용 생물공정에 백색부후균인 Phanerochaete sp. EJ-31L을 활용할 수 있을 것으로 기대된다.

• 한국미생물·생명공학회지
• /
• 제13권2호
• /
• pp.169-172
• /
• 1985

Rhodopseudomonas K-7은 혐기 광조건과 호기암조건에서 glucose, xylose로 이용하면서 성 장할 수 있었는데, 종배양시 glucose를 첨가하는 것이 본 배양에서 glucose자화를 촉진시켰고, glucose 60mM 배지에서 배양한 것을 종균으로 했을 때, glucose이 용량이 가장 많았다. Glucose 60mM배지에서 배양한 것을 종균으로 했을 때, 배지의 glucose 농도가 높더라도 이용할 수 있는 glucose양은 제한되어 있었다. 혐기 광조건에서 보다는 호기 암조건에서 성장속도도 빨랐고, glucose, xylose자화량도 많았다.

• 미생물학회지
• /
• 제30권6호
• /
• pp.495-500
• /
• 1992

Photosynthetic bacteria which can utilize ferulate as a sole carbon source for their metabolic activities were isolated from soils by liquid enrichment culture technique. The strain P-1 was selected by the highest capability of degrading ferulate in aerobic and anaerobic conditions. The strain P-1 was rod-shaped with its motility, strained gram negatively and could not utilize sulfur compounds. This strain has the bacteriochlorophyll a group I carotenoid and membrane structures like lamellae. As the results of physiological, morphological and cultural charactderistics, the isolate was identified as Rhodopseudomonas plaustris, one of the purple nonsulfer bacteria. The strain P-1 utilized 2mM/day in aerobic condition and 0.86 mM/day in anaerobic condition.

• 치위생과학회지
• /
• 제23권4호
• /
• pp.343-350
• /
• 2023

Background: Digital panoramic dental X-ray equipment (PDX) is frequently used by patients and dental workers for diagnosis and examination in dental institutions; however, infection control has not been properly implemented. Therefore, in this study, we aimed to systematically review the potential risk of cross-infection in the dental environment by investigating the contamination level of general aerobic bacteria and Staphylococcus aureus, which are important in hospital infections, in PDX areas that people mainly contact. Methods: This survey was conducted from March to May 2023 and covered one general hospital, three dental hospitals, and nine dental clinics equipped with PDX. Bacteria samples were collected from the left-handle, right-handle, forehead support, and head side support as the patient's contact areas, as well as the X-ray exposure switch and left-click mouse button as the dental hygienist's contact areas of the PDX. The collected bacteria were spread on Petrifilm, and colonies formed after 48 hours of culture were counted. Results: General aerobic bacteria and S. aureus were detected in all areas investigated. Significant differences in bacterial counts between different regions of the PDX were observed in both groups (p<0.001). The detection rates of general aerobic bacteria (p<0.001) and S. aureus (p<0.001) were significantly higher in the contact areas of patients than those of dental hygienists. A positive correlation was observed between the forehead and the temple region in terms of general aerobic bacteria and S. aureus detection (r=1) (p<0.01). Conclusion: Taken together, the presence of many bacteria, including S. aureus, detected in PDX indicates that PDX has a potential cross-infection risk. Our results therefore highlight the need for the development of appropriate disinfection protocols for reusable medical devices such as PDX and periodic infection prevention training for hospital-related workers, including dental hygienists.

• 육가공
• /
• 통권35호겨울호
• /
• pp.46-55
• /
• 2008

본 연구의 목적은 시판 중인 스타터를 이용한 발효육제품과 스타터를 이용하지 않고 자연발효시킨 육제품의 발효 및 숙성 중 미생물학적, 이화학적인 특성에 미치는 영향을 연구하고, 원료육에서의 전자선 조사(2 kGy) 효과를 검증하고자 한다. 2 kGy로 전자선 조사한 스타터 첨가구는 발효 및 숙성 중 pH가 급격히 감소하였으며(p<0.05), 최종 pH 는 4.25를 나타내었다. 총균수와 젖산균수는 스타터 첨가에 의해 좌우되는데 발효가 진행됨에 따라 총균수와 젖산균수가 유사한 경향을 나타내었다. TBARS 값은 발효 및 숙성기간이 증가함에 따라 모든 처리구에서 증가하였다. 본 연구결과를 통해 발효육 생산 전 2 kGy로 전자선 조사처리한 경우 총균수를 감소시키고 젖산균수는 증식하는 것을 확인하였다. 조사처리 후 육에 스타터를 첨가하게 되면 발효육 생산에 매우 유용하게 이용될 수 있을 것으로 사료된다.