농산물의 증산을 위한 과도한 농약 사용으로 인한 토양 생태계의 파괴를 줄이기 위하여 맹독성 농약을 대신할 수 있는 생물학적 방제제 개발의 일환으로 식물병원성 진균의 생육을 억제하는 siderophore를 생산하는 생물학적 방제균을 선발하여, 이를 동정하고 근부병균억제기작을 연구하여 향후 다기능 생물학적 방제제 개발의 기초자료를 활용하고자 하였다. 이를 위해 저병해 경작지 토양에 장기간 우점화 되어 있는 siderophore 생산 가능성이 높은 토착 길항미생물을 전국 각지의 저병해 경작지에서 분리하였고, 이들 중 siderophore 생산능이 높은 길항미생물 4종의 균주를 chrome azurol S(CAS) agar를 이용하여 선발하였다. 그 중 최고의 길항성을 나타내는 GL7 균주를 최종 선발하였고, API diagnostic test와 지방산 분석, 그리고 각종 생리학적 특성 및 형태학적 특성을 통해 동정한 결과 Pseudomonas fluoresceus의 한 균주임을 확인하였다. 최종 선발된 siderophore 생산균주 P. fluorescens GL7의 길항기작을 병원성 진균인 Fusarium solani를 대상으로 균사 생장과 포자 발아 등의 억제율을 조사한 결과 균사 생장 억제율은 75% 이상이며, 포자 발아억제율은 97% 이상으로 우수한 방제능을 확인할 수 있었다. 선발된 siderophore 생산능이 높은 길항균주 P. fluo-rescens GL7을 대상으로 토양 내에서 실제로 근부병에 방제력이 있는가를 조사하기 위해 강낭콩 종자(Phaseolus vulgaris L.)를 발병 기주식물로 사용하여 방제시험을 한 결과 F. solam만 처리한 경우는 30%의 성장율을, P. fluorescens GL7 균주와 F. solani와 함께 처리한 경우는 95% 정도의 성장율을 나타내어 약 65% 정도의 발병율을 줄일 수 있었다. 또한 F. solani와 P. fluorescens GL7을 처리하지 않은 무처리구에 비해 식물 물게가 147% 정도로 증가하여 식물의 생육도와 뿌리의 발육상태가 양호하였고, 근부병 발생도 거의 볼 수 없었으므로 아주 우수한 siderophore 생산성 생물학적 방제균을 선발할 수 있었다.

Among microorganisms isolated from soil, YJ-66 strain was the best producer of flocculant and was examined for flocculating ability in the active carbon and CaCl2. YJ-66 strain was the best producer of flocculant and was examined for flocculating ability in the active carbon and CaCl2. YJ-66 strain was identified to be a species belonging to the genus Achromobacter. The optimum culture condition for production of bioflocculant with the isolated strain was for 72hrs at 3$0^{\circ}C$ and pH7.5. The favorable carbon, nitrogen sources and inorganic salts for production of the flocculant were sucrose, peptone, MgSO4 and KH2PO4, whose optimal concentrations were 2%. 0.067%, 0.1% and 0.1%, respectively. Addition of the carbon and inorganic salts significantly increased the production of flocculant. Compositions of optimized culture medium for bioflocculant production by Achromobacter sp. YJ-66 were 2% sucrose, 0.067% peptone, 0.1% MgSO4 and 0.1% KH2PO4 in initial pH 7.5 during at 3$0^{\circ}C$ for 72hrs.

In order to investigate structure-antibiotic activity relationships of brevinin-1 and thanatin containing Rana box composed of basic loop formed by disulfide bridge in their arboxy terminus, thanatin, brevinin 1 and their analogues (T-B1, T-B2 and B-T) in which their Rana box sequence exchanged was designed and synthesized by the solid phase method using Fmoc-chemistry. The basic sequence of Rana box of thanatin had more significant effect on both antibacterial and antifungal activity than that of brevinin 1. The tail sequence (QRM) of thanatin was found to be important in its antibacterial and antifungal activity. Rana box sequence of brevinin-1 did not have a significant effect on its antitumor and phospholipid vesicle-aggregating activities. Brevinin-1 showed stronger $\alpha$-helical structure in the membrane-mimicking environment such as SDS micelle than thanatin. A remarkable increase in a-helicity of bervinin-1 plays more important role in antibiotic activity than that of thanatin. Furthermore, antibacterial activity of thanatin against E. coli resulted from the disruptive effect against the outer cell membrane of E. coli.

The protease produced by Mucor racemosus f. racemosus PDA 103 from meju was purified by precipitating with 80% saturated ammonium sulfate, CM Sephadex C-50 ion-exchange chromatography, and secondary Sephadex G-100 gel filtration chromatography. The specific activity of the purified enzyme was 60.1unit/mg protein and the purification fold of the enzyme was 83.5. The molecular weight of the enzyme was estimated 33,746Da and the enzyme was elucidated as monomer by LC-MS and SDS-PAGE. The number of amino acids was evaluated about 330 residues.

Several bacterial strains utilizing crude oil as their sole carbon and energy sources were isolated from marine. One of the strains named KCL-1 showed the highest degradative activity for crude oil and the best growth rate. This strain was identified as a Klebsiella sp. based on the morphological, biochemical, and physiological characteristics. The optimum cultural conditions were as follows; $32^{\circ}C$~$37^{\circ}C$ for temperature and 7.0 for initial pH. Additionally, the optimal concentration of sodium chloride was 3.0%, indicating that this strain was derived from seawater. KCL-1 could use several kinds of n-alkane hydrocarbons from octadecane to hexacosane as a sole carbon source. The degradation of crude oil by KCL-1 was stimulated by addition of octadecane in the culture. The emulsifying activity by KCL-1 was highest after 3 days of cultivation under the condition of 3.0% sodium chloride, pH 7.0 and $37^{\circ}C$.

Streptomyces luteogriseus KT-10 isolated from Korean farm soil produced a strong cathepsin B inhibitor. Optimal conditions for the cathepsin B inhibitor production by s. luteogriseus KT-10 were evaluated. The cathepsin B inhibitor was produced with maximal yield in the cultural condition of pH 7.0 and $25^{\circ}C$ for 4 days. Optimal medium for the cathepsin B inhibitor production was determined to be a medium containing 20g, peptone 3g, yeast extract 1g, K2HPO4 0.5g, MgSO4.7H2O 0.5g, NaNO3 0.5g, NaCl 0.5g per l. The cathepsin B inhibitor produced by S. luteogriseus KT-10 could also inhibit the other proteinases such as trypsin, papain, and cathepsin D.

Protease production and its characteristics were investigated with Mucor racemosus f. racemosus PDA 103 which was isolated from Korean traditional meju. Optimum culture conditions of the strain for the production of the protease in basic medium[bean(Baektae):H2O=1:1(w/v)] were as follows: pH 6, 3$0^{\circ}C$ and 72hrs. Optimum pH and temperature for the enzyme activity of the protease produced by Mucor racemosus f. racemosus were pH 5 and 5$0^{\circ}C$, respectively. The enzyme was relatively stable a pH2.0~5.0 and at temperature below 4$0^{\circ}C$. Phenylmethane-sulfonyl fluoride and Ag+ inhibited the enzyme activity. This indicates that the enzyme is serine protease. Km value was 0.9$\times$10-4M and Vmax value was 5.93$\mu\textrm{g}$/min. This enzyme hydrolyzed casein more rapidly than bovine albumin.

Inulin fructotransferase(depolymerizing)(EC 2.4.1.93)(inulaseII) which converts inulin into di-D-fructofuranose-1,2':2,3'-dianhydride (DFAIII) was purified from Arthrobacter ureafaciens KCTC 3387 using column chromatography on DEAE-Toyopearl 650M and gel filtration of Sephadex G-200. The enzyme was purified 7-fold with a yield of 11% from a culture supernatant. The purified enzyme gave a single band on polyacrylamide gel electrophoresis, and the molecular weight of the enzyme was estimated to be 45,000 by SDS-polyacrylamide gel electrophoresis. The optimum pH and temperature for the enzyme reaction were pH6.5~7.0 and $55{\circ}C$, respectively. The enzyme was stable within a pH range of 5.0 to 10.6 and up to $60^{\circ}C$. The Km of this enzyme for DFAIII production was 11.9mM. The enzyme was inactivated by $Hg^{2+}$ and after exhaustive digestion of inulin by this enzyme, 1-kestose and nystose were produced in addition of DFAIII.

For Trametes sp. CJ-105, a kind of white-rot fungi which was collected from the mountain of Korea and was proven to be effective in decolorizing a wide range of structurally different synthetic dyes, the optimum conditions for mycelial growth and laccase(E.C. 1.10.3.2) production were investigated. Among various carbon sources, glucose showed the highest potential for the mycelial growth and laccase production, the optimum concentration being 2% glucose. For the nitrogen source, asparagine was good for the mycelial growth, while ammonium tartrate for laccase production(optimum concentration: 0.04%). The addition of thiamine and biotin increased both th emycelial growth and laccase production. When 2,5-xylidine was added as an inducer after the first day of culture, the production of alccase was seven-times higher than that in the absence of the inducer. The optimum pH and temperature conditions for laccase production by Trametes sp. CJ-105 were pH 5.0 and $25^{\circ}C$, respectively. In the 5L fermentation, the production of laccase reached a maximum of 340U/ml at the time when the ammonium ion was being rapidly depleted.

Various materials including sodium alginate, k-carrageenan, collagen and polyacrylamide were studied in order to maintain the stability of bioluminescence of Photobacterium for the monitoring of volatile toxic substances. Kinetic parameters of specific rate($\mu$), and gamma(${\gamma}$) value were determined for the relationship between bioluminescence of immobilized P. phosphoreum and toxic substances. The bioluminescence intensity was found to be proportional to the concentration of toxic substances and the free cells were shown to be more sensitive than immobilized cells when volatile substances were exposed to the cells. Bioluminescence increased slightly after several minutes, which was due to the volatility of toxic compounds. Furthermore, P. phosphoreum immobilized on strontium alginate was better than cells immobilized on sodium alginate for the response to substances used.

A great variety of the volatile metabolic by-products was formed in yeast cell during alcohol fermentation. The seibel grape (Vitis labrasca) which was grown in the Southern Korea used for wines. The objective of this research was to identify the volatile flavor compounds during alcohol fermentation and aging at 12$^{\circ}C$. saccharomyces cerevisiae and Schizosaccharomyces pombe were inoculated and fermented in seibel grape must. The volatile flavor compounds of logarithmic, stationary and death phases were extracted, concentrated and identified by gas chromatography/mass spectrometer (GC/MS). The volatile flavor compounds were determined by a Hewlett-Packard 5890 II Plus GC which was equipped with Supelcowax 10 fused silica capillary column (60m$\times$0.32mm$\times$0.25${\mu}{\textrm}{m}$ film thickness) wall coated with polyethyleneglycerol. The scan detection method allowed the comparison of the spectrum from the chromatogram of volatile flavor compounds to those in data Wileynbs base library. Among the volatile compounds collected by ether-hexane extraction method, the evolution of 20 main compounds, such as 9 esters (ethyl butyrate, isoamyl acetate, ethyl caproate, n-hexyl acetate, ethl caprylate, ethyl caprate, diethy succinate, ethyl hexadecanoate, 2-pheneethyl acetate), 4 alcohols (3-methyl-1-butanol, 1-hexanol, 1-heptanol, benzoethanol), 4 ketones and acids (2-octanone, caproic acid, caprylic acid, capric acid), 2 furan and phenol (2,6-bis(1,1-dimethyl ethyl)phenol, 2,3-dihydrobenzofuran) were observed during alcohol fermentation and aging. The production of the esters during alcohol fermentation with S. cerevisiae was higher than those of Sch. pombe. The sensory scores of the aged wine samples in aroma, taste and overall acceptability were not significantly different(p<0.05).

Several white-rot fungi collected from the mountains of Korea were evaluated for their ability to decolorize azo, polymeric, and reactive dyes. Strains CJ-105, CJ-212 and CJ-315, identified as Trametes sp., Pleurotus sp. and Fomes sp., respectively, showed higher potential for decolorization of those dyes in either solid or liquid media. For Trametes sp. CJ-105, 100ppm of Remazol Brilliant blue R and 500ppm of Acid Red 264 were completely decolorized after 2 days under liquid culture. The dominating ligninolytic enzyme existing in the culture broth was laccase (E.C. 1.10.3.2). Also, Pleurotus sp. CJ-212 and Fomes sp. CJ-315 showed similar patterns in decolorization of Remazol Brilliant Blue R and Acid Red 264. The extent of decolorization of the dyes in liquid culture was found to be proportional to the activities of the ligninolytic of decolorization of the dyes in liquid culture was found to be proportional to the activities of the ligninolytic enzymes produced by each strain. In addition to that Trametes sp. CJ-105 was highly effective in degradation of polycyclic aromatic hydrocarbons and pentachlorophenol by the activity of the ligninolytic enzymes produced. In this study, we found that white-rot fungi, Trametes sp. CJ-105(KFCC 10941), Pleurotus sp. CJ-212(KFCC 10943) and Fomes sp. CJ-315(KFCC 10942), were effective in decolorizing a wide range of structurally different synthetic dyes, as well as some chemical compounds which are known to be hardly degradable.

Forty seven amylolytic Bifidobacterium strains were isolated on starch-containing agar medium from the faecal samples of the various age groups of Korean. From these amyloytic Bifidobacterium spp., two strains of KFRI 1535, identified temporarily as Bifidobacterium longum, and KFRI 1550, identified as Bifidobacterium breve, showed great macrophage-stimulating activity for the production of tumor necrosis factor-$\alpha$ and inteleukin-6. As the cell concentration increased the cytokine production increased, although in some strains the cytokine levels started to decline over cell concentration increased the cytokine production increased, although in some strains the cytokine levels started to decline over cell concentration of $250\mu\textrm{g}$/ml. the strains which showed high cytokine-stimulating activity generally showed greater production of nitric oxide even though differences were less between strains. Selected Bifidobacterium strains were compared for their fermentation capability in saccharified rice solution and in apple pomace mixture.

From the soils collected seasonally at the 0.5~2cm and 50$\pm$1cm depths of riverside, different strains of actinomycetes were isolated and identified to the genus. At the 0.5~2cm depth, Streptomyces and rare actinomycetes were in total 73 and 62 strains, respectively. Streptomyces was approximately 2-fold more in spring and autumn than summer, and rare actinomycetes was at least 4-fold more in autumn and winter than spring. At the 50$\pm$1cm depth, Streptomyces and rare actinomycetes were in total isolated 53 and 41 strains, and these were at least 2-fold more diverse in autumn than spring, summer, and winter.