• 보존과학회지
• /
• 제26권3호
• /
• pp.259-268
• /
• 2010

본 연구는 2007년 4월에서 6월까지 국내 8기의 석조문화재를 대상으로 환경요인과 엽록소 a 및 색에 따른 생물오염 등급을 평가하였다. 엽록소 a 의 경우 $16.2{\sim}136.6{\mu}g{\cdot}g^{-1}$의 농도를 나타냈으며, 색은 녹색에서 검정색의 범위로 나타났다. 생물오염등급 평가 결과 물걸리삼층석탑과 수타사삼층석탑은 3등급을 나타냈고, 괘석리사사자석탑 및 5개의 문화재는 4등급 이상을 나타냄으로써 생물오염이 심각한 것으로 나타났다. 기중조류는 총 32분류군이 출현하였으며, 이 중 남조강은 16분류군이고, 녹조강은 13분류군이며 규조강은 3분류군으로 나타났다. 엽록소 a와 생물오염등급 간의 상관 분석 결과, 상관계수는 0.43을 나타냈다. 엽록소 a와 출현종 간의 상관분석에서 Trebouxia sp.와 Chroococcus bituminosus는 상관계수 0.89와 0.65로써 높은 상관성을 나타냈다. 생물오염등급과 출현종의 경우에는 Chroococcus bituminosus, Aphanocapsa grevillei, Xenococcus acervatus, Chlorella vulgaris 및 Synechocystis pevalekii 등이 상관계수 0.54~0.65의 범위로 높은 상관성을 나타냈다.

• Journal of Microbiology and Biotechnology
• /
• 제12권1호
• /
• pp.114-120
• /
• 2002

A 1,989-bp genomic region encoding nickel resistance genes was isolated from Legionella pneumophila, a pathogen for legionellosis. From a sequencing and computer analysis, the region was found to harbor two structural genes, a nreB-like protein gene (1,149 bp) and a nreA-like protein gene (270 bp), in a row. Both genes exhibited a significant degree of similarity to the corresponding genes from Synechocystis sp. PCC6803 ($54\%$ amino acid sequence identity) and Achromobacter xylosoxidans 31A ($76\%$). The gene was successfully expressed in E. coli MG1655 and conferred a nickel resistance of up to 5 mM in an LB medium and 3 mM in a TMS medium including gluconate as the sole carbon source. E. coli harboring the nickel resistance gene also exhibited a substantial resistance to cobalt, yet no resistance to cadmium or zinc. Since the extracellular concentration of nickel remained constant during the whole period of cultivation, it was confirmed that the nickel resistance was provided by an efflux system like the $Ni^2＋$permease (nrsD) of Synechocystis sp. strain PCC6803. Since polyphosphate (poly-P) is known as a global regulator for gene expression as well as a potential virulence factor in E. coli, the nickel resistance of a ppk mutant of E. coli MG 1655 harboring the nickel resistance gene from L. pneumophila was compared with that of its parental strain. The nickel resistance was significantly attenuated by ppk inactivation, which was more pronounced in an LB medium than in a TMS medium.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2003년도 춘계 학술발표대회
• /
• pp.126-126
• /
• 2003

Sucrose-phosphate synthase (SPS) is a key regulatory enzyme in sucrose synthesis. To investigate the role of SPS in carbon partitioning, we produced transgenic rice plants overexpressing a cyanobacterial SPS from Synechocystis sp. PCC 6803. The gene was expressed under the control of the maize Ubil promoter in transgenic plants. Southern and Northern blot analyses confirmed the integration and the expression of the transgene in four transgenic rice lines. All of the four transgenic! lines analyzed showed abnormal vegetative and reproductive developments. Analysis of SPS activities and primary metabolites in the transgenic rice plants will be presented.

• Bulletin of the Korean Chemical Society
• /
• 제18권8호
• /
• pp.874-880
• /
• 1997

Various classes of phospholipids were investigated for the structural determination of fatty acyl groups by fast atom bombardment tandem mass spectrometry (FAB-MS/MS). Phospholipids were desorbed by FAB as molecules chelated with sodium ion (or ions). Collision-induced dissociation (CID) of intact sodium adduct molecular ions ([M+Na]+, [M-H+2Na]+ or [M+Na-2H]-) produced a series of homologous fragment ions via the charge-remote fragmentation along the fatty acid chains. These ions were found useful to locate the double bond positions even for the polyunsaturated fatty acid chains. The regiospecificity of the acyl chain linkages in phosphatidylcholine (PC) could also be determined based on the ratio of relative abundance of the product ions (i.e., [M+Na-85-R2COOH]+ vs [M+Na-85-R1COOH]+) in CID-MS/MS of [M+Na]+. These are generated by the loss of fatty acyl groups at sn-1 and sn-2, respectively, together with the choline group. In all the phospholipid compounds investigated, loss of the fatty acid at the sn-2 position was dominant. The present method was applied to the structural determination of molecular species of phosphatidylglycerols (PG) isolated from cyanobacterium Synechocystis sp. PCC 6803.

• KSBB Journal
• /
• 제29권3호
• /
• pp.155-164
• /
• 2014

Succinic acid, a representative biomass-derived platform chemical, is a major fermentation product of Actinobacillus succinogenes. It is well known that carbon dioxide is consumed during the succinate fermentation, but the biochemical mechanism behind this phenomenon is not yet understood well. In this study, it was found that the addition of carbonic anhydrase (CA)s into media significantly enhances the succinic acid production by A. succinogenes during the fermentation supplied with carbon dioxide. It is likely that the (bi) carbonate produced by the CA activity from gaseous carbon dioxide is favoured by A. succinogenes for consumption and utilization. Therefore, the $MgCO_3$ requirement could be significantly reduced without compromising the succinate productivity. Furthermore, because of too high price of the commercial carbonic anhydrase, it was undertaken to economically overproduce a cyanobacterial carbonic anhydrase by the use of a recombinant Pichia pastoris. An expression vector system was constructed with the carbonic anhydrase gene PCR-cloned from Cyanobacterium Synechocystis sp., and introduced into P. pastoris for fermentation studies. About 95.9 g/L of succinic acid was produced in the production medium with 30 ppm of carbonic anhydrase, approximately 2 fold higher productivity compared to the parallel process with no supplementation of the enzyme. It is expected that this method can provide a valuable way of overcoming inefficiencies inherent in gas supply during $CO_2$-based bioprocesses like succinic acid fermentation.

• 한국축산시설환경학회지
• /
• 제11권2호
• /
• pp.135-146
• /
• 2005

본 연구는 돈 분뇨 액비에 미생물 첨가가 배추의 발아지수에 미치는 효과를 구명하기 위해서 수행하였다. 돈 분뇨 액비는 107일 동안 폭기와 무폭기 상태로 액상비료를 제조하여 공시하였고 미생물 첨가는 $0.05\%,\;0.1\%,\;0.2\%,\;0.3\%$ 수준으로 하였다. $0.05\%$ 미생물 접종 처리구에서 식물 독성이 낮고 발아지수가 높게 나타났다. 첨가수준별 돈분 액비 이용시험에서 초기 돈 슬러리의 액비성상은 T-N 2,873 ppm, T-P 753 ppm, $NH_4-N$ 1,441.6 ppm, $NO_3-N$ 16.48ppm으로 50일이 되면서 폭기조건에서 T-N 3,672 ppm, T-P 164 ppm, $NH_4-N$ 183.87 ppm, $NO_3-N$ 21.97 ppm로 변화하였으며, 무폭기 조건에서 T-N 1,261 ppm, T-P 68 ppm, $NH_4-N$ 161 ppm, $NO_3-N$ 16.87 ppm로 나타났다. 미생물을 처리하지 않고 107일동안 폭기조건과 무폭기 조건으로 액비화한 시료의 발아지수는 각각 83과 40.4이였다. 돈 분뇨 액비를 무산소 제조시 $40\%$ 이상, 호기제조시 $50\%$ 이상의 발아지수가 개선되었다. 이와 같은 결과는 액비제조 처리가 무산소 제조보다는 호기제조 처리가 작물에 양호한 것으로 판단되어지며 이는 호기처리시 총질소의 함량을 높게 유지할 수 있도록 하는 결과인 것으로 사료된다.