• 한국식품과학회지
• /
• 제23권2호
• /
• pp.161-166
• /
• 1991

미생물을 이용한 유용물질 생산연구의 일환으로 토양으로부터 생물고분자 생산균주를 분리하고, 이 분리균에 대한 균학적 성질 및 생성 생물고분자의 이화학적 성상을 검토하였다. 분리균주는 Bacillus속의 한 균종으로 동정 하였으며, 알칼리 내성균주의 특징을 나타내었다. 이 균주로부터 생성된 생물고분자는 성분분석, 정색반응 및 I.R. spectrum 분석결과 단백질 함량이 높고, 일부 amino sugar가 존재하나 uronic acid는 함유하지 않았다. 그러나 cetyl pyridinium chloride에는 침전되어 산성의 생물고분자인 것으로 추정되었다.

• 한국초지조사료학회지
• /
• 제33권3호
• /
• pp.185-192
• /
• 2013

This study was carried out to investigate the influence of the seeding dates on the yield and feed value in cultivating Italian rye grass on paddy soil. The field experiment was designed in a randomized block design of 3 repetitions with seeding dates of Oct. 19 (T1), Oct. 26 (T2), Nov. 2 (T3), Nov. 9 (T4), and Nov. 16 (T5) treatments. Plant length, fresh yield, dry matter yield and TDN yield were increased with early seeding dates (p<0.05). Crude protein, Crude fat and crude ash were increased with early seeding dates (p<0.05). On the other hand, NDF, ADF and Crude fiber were decreased with early seeding dates (p<0.05). Total mineral contents were higher in the order of T4 > T3 > T5 > T1 > T2 (p<0.05). The total composition amino acid content was decreased significantly (p<0.05) as the seeding dates delayed. Total free sugar content was highest in T1, whereas the lowest in T5 treatment (p<0.05). Nutrition yields (crude protein, crude fat, amino acid and free sugar) were increased significantly with early seeding dates (p<0.05). The above result indicated that it is favorable to seed soon after rice harvest to increase dry matter yield and nutrition yield of Italian ryegrass in the midlands.

• 자원환경지질
• /
• 제26권2호
• /
• pp.175-185
• /
• 1993

Soils and dusts collected from Changhang smelter area were analyzed for Cu, Pb, Zn, and Cd in order to determine their dispersion pattern and mode of occurrences, and to investigate the pollution level of heavy metals such as Cu, Pb, Zn, and Cd by smelting activity. The soil pH of Changhang area is in the range of 3.7~8.8, and increased with increasing distance from the smelter site. The particles containing heavy metals are several tens of ${\mu}m$ in diameter, and have well crystal form. Samples collected near the smelter show similar particle properties in size, shape, and composition, which means that they could be originated from the same contamination source. Element couples of Cu, Pb, Zn, and Cd indicate high correlation with each other, which means that Cu, Pb, Zn, and Cd could be originated from the same point source of smelter. Heavy metal contents were decayed to background levels from 2.5 kilometer away from the smelter.

• 보존과학연구
• /
• 통권24호
• /
• pp.99-130
• /
• 2003

This research carried out composition analysis the subject of potteries from kiln site at Gangwon-do, Chungcheong Nam∙Buk-do and the followings are the results. Firstly, XRD analysis results showed that soft potteries were consisted of $\alpha$-quartz, feldspar and soil minerals while hard potteries were consisted of high temperature crystals like mullite, tridymite and cristobalite. Secondly, the firing temperatures of the soft potteries were determined using XRD analysis. It ranged from $550^{\circ}C$ to $870^{\circ}C$.While the firing temperatures of the hard potteries were divided into 3 groups; Group Ⅰ: Potteries with Mullite and Feldspar - ranged from $1000^{\circ}C$ to$1200^{\circ}C$. Group II : Potteries with Mullite and Tridymite - ranged from $875^{\circ}C$ to $1200^{\circ}C$. Group III : Potteries with Cristobalite - ranged above $1200^{\circ}C$.Thirdly, the result of correlation analysis using trace element such asSc, Rb of the potteries form Gangwon do and Chungcheong Nam.Bukdokilns allowed us to divide the area with their own characteristics into 4-groups. Using the same result, kilns sited at Chungcheong Nam.Buk-do were classified into 3-groups.

• 미생물학회지
• /
• 제33권3호
• /
• pp.187-192
• /
• 1997

토양으로부터 biosurfactant를 생산하는 미생물을 분리하여 Tsukamurella sp. 26A로 동정하였다. Biosurfactant 생산을 위한 최적 배지 조성은 n-hexadecane 7%, $NaNO_{3}$ 0.2%, $K_2HPO_4$ 0.001%, $MgSO_{4}$ center dot $7H_{2}O$ 0.02%, $CaCl_2$ center dot $2H_{2}O$ 0.02%, yeast extract 0.02%(pH 6.8-7.0, 30^{\circ}C.$ )이었으며 배양액의 최저 표면장력과 계면장력은 각각 30mN/m, 1.5mN/m였다. 유화기질로서 hydrocarbon류, edible oil류, 그리고 petroleum oil등에 작용시켰을 경우 비교적 높은 유화활성과 유화 안정도를 나타내었다.

• Journal of Microbiology and Biotechnology
• /
• 제19권6호
• /
• pp.588-595
• /
• 2009

A bacterial strain, YK-2, was isolated as a producer of trans glutaminase from a forest soil sample of Daegu, Korea. The isolate showed a G+C content of 72.7 mol%, contained meso-$A_2pm$ as the cell-wall amino acid, and possessed menaquinone MK-9 ($H_6$) and menaquinone MK-9 ($H_8$) at a ratio of 6:4. The chemotaxonomic analysis, as well as phylogenetic analysis based on the 16S rDNA sequence, identified the isolate as a member of Streptomyces platensis. For transglutaminase production, the optimum medium composition was determined to be 2% glucose, 1% polypeptone, 1% soy tone, and 0.1% $MnCl_2$. The transglutaminase was stable within the pH range of 5.0-9.0 and $30-45^{\circ}C$, and the optimum pH and temperature were pH 8.0 and $45^{\circ}C$, respectively, without any requirement for $Ca^{2+}$.

• Journal of Microbiology and Biotechnology
• /
• 제24권11호
• /
• pp.1473-1483
• /
• 2014

Reports of herbicide resistance events are proliferating worldwide, leading to new cultivation strategies using combinations of pre-emergence and post-emergence herbicides. We analyzed the impact during a one-year cultivation cycle of several herbicide combinations on the rhizobacterial community of glyphosate-tolerant Bt-maize and compared them to those of the untreated or glyphosate-treated soils. Samples were analyzed using pyrosequencing of the V6 hypervariable region of the 16S rRNA gene. The sequences obtained were subjected to taxonomic, taxonomy-independent, and phylogeny-based diversity studies, followed by a statistical analysis using principal components analysis and hierarchical clustering with jackknife statistical validation. The resilience of the microbial communities was analyzed by comparing their relative composition at the end of the cultivation cycle. The bacterial communites from soil subjected to a combined treatment with mesotrione plus s-metolachlor followed by glyphosate were not statistically different from those treated with glyphosate or the untreated ones. The use of acetochlor plus terbuthylazine followed by glyphosate, and the use of aclonifen plus isoxaflutole followed by mesotrione clearly affected the resilience of their corresponding bacterial communities. The treatment with pethoxamid followed by glyphosate resulted in an intermediate effect. The use of glyphosate alone seems to be the less aggressive one for bacterial communities. Should a combined treatment be needed, the combination of mesotrione and s-metolachlor shows the next best final resilience. Our results show the relevance of comparative rhizobacterial community studies when novel combined herbicide treatments are deemed necessary to control weed growth.

• The Korean Journal of Ecology
• /
• 제12권4호
• /
• pp.257-284
• /
• 1989

This study was carried out to characterize pinus densiflora forests in middle province (Mt. Seolag, Mt. Taebaik) south province (Mt. Sokli, Mt. Jiri) and south-coast province (Mt. Daedun) of Korea. The appearance species in the P. densiflora alliance included 325 taxa and varied according to the direction of slopes. The steeper the slope was, the fewer number of taxa were observed. The floristic composition of south-coast province was gradually changing to the south hemispheric factors. Dominant species groups of P. densiflora alliance were classified into P. densiflora, Quercus serrata ( layer), Rhus trichocarpa ( layer), Lespedeza maximowiczii var. tomentella (S layer), Artemisia keiskeana, Carex humilis var. nana, Spodiopogon sibiricus (K layer). Quercus variabilis, Fraxinus sieboldiana and Styrax japonica association were formed under the P. densiflora alliance. Quercus, Rhus, Lespedeza and Rhododendron groups maintained high ecological relationships one another. The soil factors (pH, organic matters, and water field capacity)and relative light intensity tended to show negative correlation, which were significantly different among provinces. The P. densiflora forests of Korea were classified into one alliance and four associations, that is, pinion densiflorae Suz.-Tok. 1966, Quercetum variabilae ass. nov., Quercetum mongolicae ass. nov. Fraxinetum sieboldianae ass. nov. and Styraxetum japonicae ass. nov.

• 대한치과기공학회지
• /
• 제21권1호
• /
• pp.139-144
• /
• 1999

토양시료로부터 치아우식원인균인 S. mutans에 대하여 항균력을 나타내는 방선균주를 순수분리하여 분리균주를 공시균주로 하여 항생물질 생성에 미치는 환경인자를 규명하였다. 본 공시균주의 항생물질 생성 최적배지조성은 Bacto-soytone 1%, glucose 1%, NaCl 0.5%, $CaCO_3$ 0.1% 였으며 배지의 초기 pH는 7.0이었다. 또한 항생물질은 $28^{\circ}C$에서 진탕배양시 생성의 최적조건이었으며 본 공시균주는 24시간 유도기를 거쳐 배양 72시간째 항생물질의 생성과 더불어 균의 최대증식도를 나타내었다.

• 한국환경보건학회지
• /
• 제30권2호
• /
• pp.123-132
• /
• 2004

The purpose of this study was to characterize background mass concentration of PM$_{10}$ and metallic composition from September 2001 to August 2002 in comparison with Asan and Seoul. Annual mean of PM$_{10}$ concentrations in Asan and Seoul were 47.98 and 75.33$\mu\textrm{g}$/㎥, respectively. The concentrations of PM$_{10}$ were highest in spring season in both cities. The concentrations of measured metals except for As and Pb in Asan were higher than those in Seoul. Yellow dust could affect the mass and metals concentrations of measured PM$_{10}$ in Asan and Seoul. Relationship between measured metals concentrations showed that Si and Fe were associated with natural sources such as soil. Pb, Cu and Zn were closely related to urban anthropogenic sources such as fuel combustion. Especially, relationship between metals showed different association during yellow dust. Proper management for PM$_{10}$ will need in Asan, considered the concentrations of metallic elements in PM$_{10}$ in Asan were relatively higher than those in Seoul.se in Seoul.