• 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.

• 한국수산과학회지
• /
• 제7권2호
• /
• pp.69-78
• /
• 1974

국립부산수산대학 6호 실험 양어지에서 $1972\~1973$년 2년 동안 용존 산소량의 일중변화 및 Plankton과 물 변화를 조사한 결과는 다음과 같다. 1) 일중 DO의 변화는 plankton과 수온에 밀접한 관계가 있으며 식물성 Plankton이 풍부하고 어류가 많은 못에서 일일 용존산소량의 변화를 보면, 맑으며 고온인 날은 비오고 바람부는 날에 비해 낮과 밤의 격차가 매우 심하였며, 어떤 경우에는 낮 최고 23.95ppm(포화도 $328\%$)이던 것이 새벽에는 0.39ppm ($5\%$)까지 내려가서 어류를 폐사케 하는 일도 있었므로 이런 경우는 밤과 새벽 사이에 특별한 산소공급 대책이 강구되어야 할 것이다. 2) 식물성 Plankton은 23과 55속 133종 검출되었으며 종류는 녹조류가, 양에는 남조류가 가장 우세하였다. 3) 동물성 plankton은 11과 11속 12종이었고 량은 시기적으로 뚜렷한 변화를 볼 수 없었다. 4) 1972년 및 1973년의 최고온기인 8월 중순에 (수온 $30^{\circ}C$ 이상) 이었던 물 변화의 원인은 남조류인 Synechocystis aquatilis의 갑작스런 사멸에서 일어났으며 어류의 대량 폐사를 동반하였다. 8월 고온기에 S. aquatilis의 대량발생은 DO양이 하루동안에 심한 변화를 일으키게 하였으며 이런 때에 수온이 극히 높아지면($33.5^{\circ}C$) 사멸하고 그 후 부패 분해로 인한 수질의 악변으로 양식중인 다양의 어류에 피해를 주었다. 그러나 그 후부터 분해가 끝나면 곧 이어서 다시 이 종류의 Plankton이 발생하는 것으로 보아 자신에게 유독한 물질을 형성하지는 않는 것 같다.

• 한국미생물·생명공학회지
• /
• 제30권3호
• /
• pp.199-205
• /
• 2002

활주운동은 편모의 작용없이 고체의 표면을 미끄러지듯이 이동하는 박테리아의 운동방식으로 분류학상 다양한 종의 박테리아에서 발견된다. 지금까지 밝혀진 바에 의하면 활주 운동은 type IV pili(Tfp)를 필요로 하는 경우와 이를 필요로 하지 않는 두 가지로 크게 구분될 수 있는데, Tfp를 필요로 하는 경우에는 T룰의 확장과 수축에 의해 이루어지는 twitching motility와 운동기작이 흡사할 것으로 추정된다 Tfp를 필요로 하지 않는 활주운동에 대해서는 여러 다양한 모델이 제시되었는데, 이중 한 모델은 활주박테리아가 점액을 분출함으로서 추진력을 얻어 앞으로 진행한다는 설명이며, 다른 모델들은 외벽에 세포 전체를 감싸는 운동기구가 존재한다는 것이다. 이와 같이 활주운동은 일반적으로 잘 알려진 편모에 의한 운동과는 전혀 다른 운동방식에 의해 이루어지는데, 그 작용 기작이 매우 흥미로운 반면에 많은 부분들이 풀어야 될 숙제로 남아있어 앞으로의 연구결과들이 기대된다.

• Journal of Microbiology and Biotechnology
• /
• 제20권3호
• /
• pp.460-466
• /
• 2010

A mutant of green fluorescent protein ($GFPmut3^*$) from the jellyfish Aequorea victoria was cyclized in vitro and in vivo by the use of a naturally split intein from the dnaE gene of Synechocystis species PCC6803 (Ssp). Cyclization of $GFPmut3^*$ was confirmed by amino acid sequencing and resulted in an increased electrophoretic mobility compared with the linear $GFPmut3^*$. The circular $GFPmut3^*$ was $5^{\circ}C$ more thermostable than the linear form and significantly more resistant to proteolysis of exopeptidase. The circular $GFPmut3^*$ also displayed increased relative fluorescence intensity. In addition, chemical stability of $GFPmut3^*$ against GdnHCl revealed more stability of the circular form compared with the linear form.

• 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.

• 환경생물
• /
• 제36권3호
• /
• pp.424-437
• /
• 2018

The incidence of freshwater algal bloom has been increasing globally in recent years and poses a major threat to environmental health. Cyanobacteria are the major component of the bloom forming community that must be monitored frequently. Their morphological identities, however, have remained elusive, due to their small size in cells and morphological resemblances among species. We have analyzed molecular diversity and seasonal changes of cyanobacteria in Paldang Reservoir, Korea, using morphological and 16S rRNA pyrosequencing methods. Samples were collected at monthly intervals from the reservoir March-December 2012. In total, 40 phylotypes of cyanobacteria were identified after comparing 49,131 pyrosequence reads. Cyanobacterial genera such as Anabaena, Aphanizomenon, Microcystis and Synechocystis were predominantly present in samples. However, the majority of cyanobacterial sequences (65.9%) identified in this study were of uncultured origins, not detected morphologically. Relative abundance of cyanobacterial sequences was observed as high in August, with no occurrence in March and December. These results suggested that pyrosequencing approach may reveal cyanobacterial diversity undetected morphologically, and may be used as reference for studying and monitoring cyanobacterial communities in aquatic environments.

• 한국환경보건학회지
• /
• 제24권3호
• /
• pp.131-136
• /
• 1998

Attached algal community and several physico-chemicai characters were investigated at Seokjong hot spring in Chollabukdo in February and in April, 1997. The results of physico-chemicai factors are as follows : water temperatures were varied from 6.5$^{\circ}$C to 32.0$^{\circ}$C; pH range was 6.9 to 7.7; The levels of electric conductivity were 105 $\mu$mhos/cm to 477 $\mu$mhos/cm; chemical oxygen demand(COD) range was 1.5 mg/l to 21.2 mg/l; ammonia concentration was 0.20 mg/l to 8.74 mg/l; nitrate concentrations were 0.36 mg/l to 2.43 mg/l; phosphate concentration was N.D. to 0.52 mg/l; sulfur concentration was 14.6 mg/l to 66.1 mg/l. Attacched algal species were identified. Totally, 63 taxa were classified and composed of 4 phylum, 4 class, 10 order, 17 family and 31 genera. The total biomass of attacched algae was $1.036 \times 10^{7}$ cells/l that composed of $5.39 \times 10^{6}$ cells/l of blue-green algae, $4.05 \times 10^{6}$ cells/l of diatom and $0.93 \times 10^{6}$ cells/l of green algae. The succession of dominant species was Synechocystis thermalis. This could be due to the thermal wastewaters. in biotic indices tests, the values of dominance index(DI) were 0.33 to 0.67 in winter, 0.18 to 0.68 in spring. The values of diversity index(H') were 1.44 to 2.69 in winter, 1.62 to 2.89 in spring. And the values of eveness index (J) were 0.31 to 0.61 in winter, 0.37 to 0.65 in spring.

• 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.