• Journal of Microbiology
• /
• 제34권4호
• /
• pp.363-369
• /
• 1996

As basic study to evaluate the treatability of oil-contaminated environment with bacteria, isolation and characterization of crude oil-degrading bacterium were carried out. A bacterial strain SH-14 capable of degrading crude oil was isolated from contaminated soils by enrichment culture technique and identified as Acinetobacter sp. by morphological, cultural and biochemical characteristics, and so named Acinetobacter sp. SH-14. The optimal medium composition and cultural conditions for the growth and emulsification of crude oil by Acinetobacter sp. SH-14 used were crude oil of 2.0%, $KNO_3$ of 0.2%, $K_2HPO_4$ of 0.05%, and $MgSO_4\;{\cdot}\;7H_2O$ of 1.0%, along with initial pH 7.0 at $30^{\circ}C$. Acinetobacter sp. SH-14 showed to be resistant to chloramphenicol and utilized various hydrocarbons such as dodecane, hexadecane, isooctane, cyclo-hexane etc., as a sole carbon source. Acinetobacter sp. SH-14 harbored a single plasmid. By agarose gel electrophoresis and curing experiment it was found that the genes for crude oil components degradation were encoded on the plasmid.

• Bulletin of the Korean Chemical Society
• /
• 제16권12호
• /
• pp.1218-1222
• /
• 1995

The pKa values of benzyltetrahydrothiophenium halides 1a-f in water have been estimated by measuring the absorbances of the solution in aqueous hydroxide ion solution. Assuming that the ratios of the activity coefficients remains close to unity, the absorbance of the solution can be expressed as A/[SH]o=(εSH+εS-K[OH-])/(1+K[OH-]), where A, [SH]o, K, εSH, and εS- are the absorbance of solution, the initial concentration of 1a-f, the equilibrium constant, and the extinction coefficients for SH and S-, respectively. The εS- and K values that best fit with this equation were calculated by a nonlinear regression analysis with a large number of absorbance data determined at different [OH-] and [SH]o. The pKa values of the SH were then calculated with the relationship Ka=-log K+14. The validity of this method has been demonstrated by the excellent agreements between the experimental and literature pKa values of three organic acids. The pKa values of 1a-f estimated by this method are in the range of 12.5-15.3 and correlate well with the Hammett equation. The large negative deviation for the pKa values of 1e and 1f from the Hammett plot has been attributed to the extra hydrogen bonding between the phenyl group and water molecules attracted by the hydrophilic substituents.

• Biomolecules & Therapeutics
• /
• 제20권3호
• /
• pp.286-292
• /
• 2012

All-trans retinoic acid (ATRA) is currently used in adjuvant differentiation-based treatment of residual or relapsed neuroblastoma (NB). It has been reported that short-term ATRA treatment induces migration and invasion of SH-SY5Y via transglutaminase-2 (Tgase-2). However, the detailed mechanism of Tgase-2's involvement in NB cell invasion remains unclear. Therefore we investigated the role of Tgase-2 in invasion of NB cells using SH-SY5Y cells. ATRA dose-dependently induced the invasion of SH-SY5Y cells. Cystamine (CTM), a well known tgase inhibitor suppressed the ATRA-induced invasion of SH-SY5Y cells in a dose-dependent manner. Matrix metalloproteinase -9 (MMP-9) and MMP-2, well known genes involved in invasion of cancer cells were induced in the ATRA-induced invasion of the SH-SH5Y cells. Treatment of CTM suppressed the MMP-9 and MMP-2 enzyme activities in the ATRA-induced invasion of the SH-SY5Y cells. To confirm the involvement of Tgase-2, gene silencing of Tgase-2 was performed in the ATRA-induced invasion of the SH-SH5Y cells. The siRNA of Tgase-2 suppressed the MMP-9 and MMP-2 activity of the SH-SY5Y cells. MMP-2 and MMP-9 are well known target genes of NF-${\kappa}B$. Therefore the relationship of Tgase-2 and NF-${\kappa}B$ in the ATRA-induced invasion of the SH-SY5Y cells was examined using siRNA and CTM. ATRA induced the activation of NF-${\kappa}B$ in the SH-SY5Y cells and CTM suppressed the activation of NF-${\kappa}B$. Gene silencing of Tgase-2 suppressed the MMP expression by ATRA. These results suggested that Tgase-2 might be a new target for controlling the ATRA-induced invasion of NBs.

• 한국수산과학회지
• /
• 제44권6호
• /
• pp.605-611
• /
• 2011

This study examined the suitability of characteristics of potential strains of probiotic bacteria. Among 25 lactic acid bacteria isolated from Korean traditional fermented food, the Hard Clam Meretrix meretrix Shikhae, the SH-10 strain, which exhibited superior resistance to low pH and bile salts, was selected as a potential probiotic bacteria. By examining carbohydrate utilization, morphological properties, and the 16S rRNA gene sequence, the SH-10 strain was identified as Pediococcus pentosaceus (hereafter, P. pentosaceus SH-10). P. pentosaceus SH-10 was resistant to amikacin, cefotetan, ciprofloxacin, gentamicin, kanamycin, nalidixic acid, streptomycin, and vancomycin. Tests of antimicrobial activities against pathogens such as Bacillus cereus, Listeria monocytogenes, Salmonella choleraesuis, and Staphylococcus aureus, indicated that P. pentosaceus SH-10 inhibited the growth of pathogenic bacteria. These results suggest that P. pentosaceus SH-10 can be developed as a probiotic bacteria.

• 생명과학회지
• /
• 제30권1호
• /
• pp.26-31
• /
• 2020

Heterosigma akashiwo는 전세계적으로 분포된 침편모조류이며, 대발생을 형성하여 많은 나라의 양식산업에 커다란 손실을 유발시킨다. 따라서 빠르고 민감한 검출방법을 개발하는 것은 유해조류 대발생에 대한 적절한 경보를 위해서 필요하다. 이 연구에서는 H. akashiwo를 정성 및 정량적으로 검출하기 위하여 뉴클레아제 보호 분석이 통합된 샌드위치 혼성(NPA-SH)을 개발하였다. NPA-SH 프로브는 여섯 종의 미세조류 핵산 서열을 이용하여 디자인 후, 특이성을 확인하여 capture 프로브와 signal 프로브를 선정하였다. 배양시료와 현장시료를 이용하여 NPA-SH의 적용성을 평가한 결과, NPA-SH의 좋은 적용성과 효과를 확인하였다. H.akashiwo의 정량분석을 위한 선형회귀식을 확인하였으며, 최소 검출한계는 1×10⁴ cells/ml이었다. NPA-SH를 사용하여 얻은 H. akashiwo의 정량결과와 현미경을 사용하여 얻은 결과 사이에는 통계학적으로 유의한 차이는 없었다. NPA-SH 분석은 환경시료에 잘 적용되었다. 이러한 결과는 NPA-SH가 H. akashiwo의 모니터링에 사용되어 왔던 전통적인 현미경적 방법에 대한 좋은 대안이 될 수 있음을 보여준다.

• 비파괴검사학회지
• /
• 제29권5호
• /
• pp.442-449
• /
• 2009

스테인레스 스틸 배관의 결함에 대한 MsS의 비틀림모드 신호와 BEM 모델링의 SH모드 신호의 특성을 살펴보았다. 비틀림모드 신호와 SH모드신호의 비교를 위해 스테인레스 스틸 배관의 결함은 깊이와 폭을 달리하면서 원주방향으로 360도 가공하였다. MsS의 비틀림모드 신호분석 결과 원주방향 결함을 모두 탐지하였으며 깊이 변화에 따라 신호 진폭의 변화가 확인되었다. 하지만 원주방향 결함의 폭 변화는 일정한 경향이 나타나지 않았다. BEM 모델링의 SH 모드 신호 분석 결과 깊이 변화의 경우 비틀림모드 신호와 유사한 결과가 나타났지만, 폭 변화는 신호 진폭의 변화가 일어났다. 본 연구를 통하여 배관의 원주방향 결함에 대한 비틀림모드와 SH모드의 비교 분석을 통하여 신호 특성을 확인하였고 배관의 축대칭 결함에 대해 SH모드 모델링으로도 신호 예측이 가능함을 알 수 있었다.

• 한국미생물·생명공학회지
• /
• 제43권4호
• /
• pp.385-390
• /
• 2015

본 연구는 식물성장촉진 근권세균인 Bacillus sp. SH1RP8를 친환경 생물비료로 이용하기 위하여 수행되었다. SH1RP8 균주를 동결건조시 세포의 용혈을 방지하도록 여러 가지 동결건조 보호제를 첨가하여 균주의 성장과 활성에 미치는 영향을 알아보았다. SH1RP8 균주의 동결건조 시 동결건조 보호제로 skim milk, glucose, peptone 등을 이용하였을 때, 그 중 5%의 skim milk를 첨가하였을 때 가장 높은 (30.6%)의 생존율을 보였다. 또한, 균주의 성장을 촉진하는 기질 그룹을 첨가하여 5%의 skim milk 단독으로 첨가한 경우와 기질 그룹을 각각 첨가한 경우의 동결건조 보호 효과를 비교하여 보았다. 그 결과 5% skim milk에 glycerol을 동시에 첨가할 경우 균주의 생존율이 skim milk 단독 첨가효과와 비교 시 214.29%의 향상율을 보여주었다. 또한 동결건조된 Bacillus sp. SH1RP8 은 매우 효과적인 PGPR로 활성을 보여주어 생물비료로서의 훌륭한 기능이 기대된다.

• 항공우주기술
• /
• 제8권1호
• /
• pp.207-214
• /
• 2009

본 연구는 미세중력 모델인 머리하향기울기(Head Down Tilt; HDT) 자세에서 운동 중저산소호흡이 심혈관계 반응에 미치는 영향을 알아보는데 있었다. 8명의 건강한 남성($23{\pm}2$ 세, 신장 $176{\pm}4$ cm, 체중 $75{\pm}8$ kg)은 4가지 조건(앉은 자세에서 정상공기 호흡: SN, 앉은 자세에서 13% 산소호흡; SH, HDT 자세에서 정상공기 호흡; SH, HDT 자세에서 13% 산소호흡; HH)에서 최대산소섭취량의 약 40% 운동강도로 15분간 싸이클링을 실시하였다. 심박수는 SH그룹이 SN그룹보다 높았고(p<0.05), HH그룹이 SH그룹보다 높게 나타났다(p<0.05). 혈중산소포화도는 SH그룹이 SN그룹보다 유의한 감소를 나타내었다(p<0.05). 이완기혈압(p<0.05) 및 평균동맥압(p<0.05)은 안정시 앉은 자세에서보다 HDT 자세에서 유의하게 낮아졌다. 체액변인인 Hb, Hct과 전해질 변인인 나트륨, 칼륨, 염소는 모든 그룹에서 차이가 나타나지 않았다(p>0.05). 대사적 변인 중 Lactate는 SH그룹이 SN그룹보다 유의한 증가를 나타내었다(p<0.05). 결론적으로, 저산소호흡과 자세의 이중자극은 심혈관계반응에 영향을 주지 않았다.

• 대한기계학회논문집A
• /
• 제25권7호
• /
• pp.1047-1054
• /
• 2001

Atomic Force Microscope (AFM) was used to study cross sectional profiles and dimensions of fatigue striations in 2017-T351 aluminum alloy. Their widths(SW) and heights (SH, SH(sub)h, SH(sub)ι) were measured from the cross sectional profiles of three-dimension AFM images. The following results that will be helpful to understand the fatigue crack growth mechanism were obtained. (1) The relation of SH=$\alpha$(SW)(sup)1.2 was obtained. (2) The ratio of the striation height to its width SH/SW, SH(sub)h/SW and SH(sub)ι/SW did not depend on the stress intensity factor range ΔK and the stress ratio R( =P(sub)min/P(sub)max = K(sub)min/K(sub)max). (3) Effect of precipitate on the morphology of striation was changed by the relative dimensional difference between the striation width SW and the precipitates. From these results, the applicability of the AFM to nano-fractography is discussed.

• 대한본초학회지
• /
• 제21권4호
• /
• pp.85-92
• /
• 2006

Objectives : To evaluate the neuroprotective effects of added Bo-Yang-Hwan-Oh-Tang (BHT), we investigated the neuronal death protection effects to oxidative damages in SH-SY5Y neuronal cells. Methods : To study the cytotoxic effects of BHT on SH-SY5Y cells, the cell viability was determined by MTT assay. To investigate the neuronal death protection of BHT, SH-SY5Y cells were induced oxidative damages by $H_2O_2$ and then assayed the cell viability and DNA fragmentation. We also investigated DPPH free radical scavenging effect of BHT by tube test. Results : In MTT assay, $1000{\mu}g/ml$ of BHT was not showed the cytotoxic effect on SH-SY5Y cells. BHT protected SHSY5Y cells from $H_2O_2-induced $ neuronal cell death in a dose-dependent manner. BHT also protected SH-SY5Y cells from $H_2O_2-induced$ DNA fragmentation. BHT effectively scavenged DPPH free radicals in a dose-dependent manner. Conclusion : These data suggest that BHT may have strong antioxidant effects through the free radical scavenging and neuroprotective effects in human neuronal cells.