Sang-Mong Lee

Influence of glycerol on production and structural-physical properties of cellulose from Acetobacter sp. V6 cultured in shake flasks.

Cost-effective production of bacterial cellulose (BC) by Acetobacter sp. V6 was investigated in shake culture using glycerol as carbon source and its structural and physical properties were determined. In medium containing 3% (w/v) glycerol, BC production was 4.98+/-0.03g/l after 7 days. This value was 3.8-fold higher than the yield in the glucose medium. FT-IR spectra revealed that all the BC samples were highly crystalline and were cellulose type capital I, Ukrainian. The crystallinity index value of the BC produced was 9% higher in the glycerol medium than in the glucose medium. Scanning electron micrographs showed that BC from the glycerol medium was more compact than that from the glucose medium. Water-holding capacity and viscosity of BC from the glycerol medium had 61.3% and 22.4% lower values than those from the glucose medium. These results suggest that glycerol could be a potential low-cost substrate for BC production by Acetobacter sp. V6, leading to the reduction in the production cost.

Antimicrobial and Anticancer Activity of Korean Traditional Soy Sauce and Paste with Chopi

The fruits of Zanthoxylum piperitum are known as having various physiology vitality, and the abstraction ingredient of the pericarp is also known as having strong antibiotic activities against various bacteria. Therefore, this study was carried out to estimate the effect of physiology vitality when the abstraction ingredient of Z. piperitum was added in soy sauce(Chopi-kanjang) and soybean paste(Chopi-doenjang). For the antibiotic activity against the pathogens of sitotoxism such as Staphylococcus aureus, Salmonella typhimurium, Vibrio parahemolyticus, Escherichia coli 0157:H7, the extracts of the Chopi-kanjang was added 1%, 2%, 4% pericarp of Z. piperitum in the manufacturing process of soy source. According to the results, the growth of E. coli 0157:H7 and V. parahemolyticus were respectively inhibited as 70% and 50% by the Chopi-kanjang added 2% of the ingredient. For the antibiotic effects of the aforementioned Chopi-kanjang against Sal. typhimurium and Sta. aureus, the growth of those pathogens was also inhibited between 40% and 60% according to the manufacturing period of Chopi-kanjang. It was confirmed that the antibiotic activity using the mixture of the abstraction ingredient and Chopi-doenjang was lower than those of Chopi-kanjang. In order to estimate the anticancer activity using by caspase-3 activity, the mixture of the abstraction ingredient of the pericarp of Z. piperitum and Chopi-kanjang was treated to leukemia cells. According to the results, the activities of caspase-3 using the mixture added 1%, 2% and 4% of the abstraction ingredient were respectively increased as much as 4, 12, 15 times comparing with the control which was treated with the soy source only. It could be that the mixture of the abstraction ingredient of the pericarp of Z. piperitum and soy source induced apoptosis, and the mixture of the abstraction ingredient and soybean paste had no effect on the activity of caspase-3. In order to find out the death of the aforementioned cells caused by necrosis or apoptosis, DNA fragmentation in the cell was examined. U-937 cells showed apoptotic DNA fragmentation in the incubation with Chopi-kanjang extract.

Isolation and Characteristics of Bacteria Showing Biocontrol and Biofertilizing Activities

To develop multifunctional microbial inoculant, microorganisms with antagonistic activity and biofertilizing activity were screened. Pantoea agglomerans and Bacillus megaterium from our laboratory culture collection, and strain MF12 from soil near poultry farm in Miryang were selected. On the basis of morphological, physiological studies and 16S rDNA sequence analysis, isolate MF12 was identified as the Bacillus pumilis. Three strains were studied for insoluble phosphate solubilization, indole-3-acetic acid (IAA) and siderophore production, ammonification ability, hydrolytic enzyme production and antifungal activity against phytopathogenic fungi. P. agglomerans did not produce any visible clear zone on agar plate containing 0.5% as a sole phosphorus source. However, this strain could solubilize insoluble phosphate in liquid medium. All strains produced IAA ranged from depending on culture time and had ammonification ability. Among three strains, only P. agglomerans produced siderophore. P. agglomerans produced pectinase and lipase, B. megaterium produced amylase, protease and lipase while B. pumilis produced protease and lipase. P. agglomerans showed antifungal activities against phytopathogenic fungi, Fusarium oxysporum and Colletotrichum gloeosporioides. B. pumilis showed antifungal activities against Botrytis cinerea, Sclerotinia sclerotiorum and Phythium ultimum.

Fermentation Characteristics of Chungkookjang Prepared Using Different Soybean

Abstract This study was carried out to investigate changes of protease and amylase activities and nitrogen content in Chungkookjang prepared by Bacillus subtilis S8 and different soybean. Amino-type nitrogen and ammonia-type nitrogen contents increased with an increase in fermentation time and was the highest in black soybean Chungkookjang. The number of viable cells increased up to 24 h of fermentation at all temperatures tested; especially, their levels were the highest at 40. Protease activity was the highest in black soybean Chungkookjang. α-amylase activity increased significantly up to 6 h of fermentation at 30and 40and then maintained constantly. It also increased up to 30-36 h of fermentation at 45and then decreased. β-amylase activity was the highest in black soybean Chungkookjang at 35and 40and in yellow soybean Chungkookjang at 45. Production pattern of reducing sugar was similar to that of β-amylase. Amino-type nitrogen, viable cell number and reducing sugar content and β-amylase activity was the highest in Chungkookjang fermented at 40. Considering amino-type and ammonia-type nitrogen contents, Chungkookjang fermentation using yellow soybean was favorable. However, the fermentation using black soybean was favorable, considering protease and amylase activities and reducing sugar content.Key words: Bacillus subtilis, Chungkookjang, Fermentation, Soybean cultivar

Optimal Condition to Produce Protease by Strain Separated from the Intestine of Reticulitermes speratus

We separated the bacteria showing protease activity from Reticulitermes speratus which is known as the only termite species in Korea. Then, we collected the best activated strain and studied the optimal culture condition for producing the enzyme. According to the results of observing morphological and physiological characteristics, and the type of 16S rRNA of the strain, it was identified as Serratia marcescens and named S. marcescens strain TM-3215. This strain showed the best activity under conditions of 0.8% (w/v) starch, 0.4% (w/v) peptone, 0.08% (w/v) MgSO₄?7H₂O, 30℃ and pH 8.0. After being cultivated under optimal conditions for 9 hr, the strain produced 19.8 U/ml of enzyme, an amount 1.8 times greater than the control.

Structural Identification of Antibiotics from Pseudomonas sp. RRj 228, a Antifungal Activity of Collectotrichum acutatum Causing Anthracnose on Pepper

Microorganisms near the plant rhizosphere usually inhabit the surface or the inside of the plant roots and have a direct effect on plant growth by secreting plant growth promoters or antagonistic materials which protect the root zone system from various pathogens. This study was carried out to identify and isolate the antagonistic materials after isolation of microorganisms showing high antagonistic activities, in hopes of contributing to the development of sustainable agriculture and the preservation of agricultural environments. A number of antagonistic bacteria were isolated from paddy soil. Among isolates, RRj 228 showed plant growth promotion and antagonistic activity. RRj 228 was identified as Pseudomonas sp. according to the results of physiological properties and genetic methods. On the basis of the results of anti-fungal spectrum against several pathogens by RRj 228, the antagonistic effect of the isolate against Botrytis cinerea, Pythium ultimum, Phytopthola capsici, and Rhizoctonia solani, especially against red-pepper anthracnose caused by Colletotrichum acutatum, was remarkable. The experiment evaluating the biological control effect by RRj 228 revealed that the value by the RRj 228 culture against C. acutatum, R. solani and P. ultimum were 0.14 mg/ml, 0.16 mg/ml and 0.29 mg/ml, respectively. An antagonistic substance was isolated and purified by several chromatographies from the RRj 228 culture. The and assignment of the antagonistic substance was achieved from two-dimensional COSY, HMQC, and HMBC. Finally, the antagonistic substance was identified as Phenazine-1-carboxylic acid (, M.W.

Comparison of Arylphorin of Antheraea pernyi with Those of Several Lepidopteran Wild Silkmoths by Western Blot Analysis.

The occurences of proteins relating to Antheraea pernyi arylphorin in haemolymph, fat body, integument, midgut and silkgland of the wild silkmoths, Antheraea yamamai, Antheraea pernyi, Samia cynthia pryeri and Actias gnoma in the 5th larval instar were investigated by immunoblot analysis using mouse polyclonal antibody against A. pernyi arylphorin as probe. In A. yamamai, A. pernyi, S. cynthia pryeri and A. gnoma, the major immunoreactive antigenic proteins with a molecular weight of 80 KDa against the antisera of the A. pernyi arylphorin were clearly observed in the haemolymph, but in the integument, fat body, midgut and silkgland of the corresponding wild silkmoths the presence of the immunoreactive proteins were very variable. These results suggest that the A. pernyi arylphorin has almost same immunological identity with those of the wild silkmoths, A. yamamai, S. cynthia pryeri and A. gnoma though the distribution of the corresponding antigenic arylphorins is different according to the tissues of the wild silkmoths.

Control effect of the newly developed insecticidal protectant on Sycamore lace bug, Corythucha ciliata (Hemiptera : Tingidae)

To determine the effects of newly developed insecticide (Ultra) on Sycamore lace bug (Corythucha ciliata), ten leaf discs were sprayed with the Ultra solution including the other selected commercialized insecticide solutions such as Carbaryl and Pirimicarb, and also with a water-sprayed control. According to the results, the control effect of Ultra on the adults and immatures was respectively 98.9% and 97.5% after 48hr, and the corresponding values were higher than that of the other tested insecticides (i.e Carbaryl showed 84.6% for adults and 85.6% for immatures; Pirimicarb showed 83.0% for adults and 90.7% for immatures). For the Susceptibility test, LC value of Ultra showed the lowest as 1.5ppm, the value of Carbaryl and Pirmicarb were 3.7 ppm and 30.4 ppm, respectively. Therefore, the insecticidal effects were better for the newly developed insecticide than the commercialized insecticides.

Partial Characterization and Induction of Ferulic Acid Esterase and Xylanase from Pseudomonas sp. LG2

Lignin degrading bacterium Pseudomonas sp. LG2 was able to degrade lignin substrate to a lot of APPL compound. APPL compound was detected in culture supernatants from Pseudomonas sp. LG2 grown with BSC(brewer`s spent grain). FAE(ferulic acid esterase) and xylanase are induced from Pseudomonas sp. LG2 in the presence of carbon sources such as oat spelt xylan, HBSG I, II(hydrolyzed brewer`s spent grain I, II) and AFBSG(autoclaved fraction from brewer`s spent grain). However, xylanase and FAE are not induced by growth of Pseudomonas sp. LG2 on xylose and arabinose. Pseudomonas sp. LG2 is grown on medium containing oat spelt xylan, HBSG I, II and AFBSG and the induction of FAE and xylanase activities of extracellular proteins determined during 14 days. Maximum level of xylanase activity(5.3 U/mg) found at 6 days in culture contained oat spelt xylan as carbon source, whereas maximum level of FAE activity(15.4 mU/mg) was found at 8 days in culture contained AFBSG as carbon source. Most ferulic acid was released in culture supernatants when Pseudomonas sp. LG2 grown on oat spelt xylan, HBSG I, II and AFBSG. FAE of extracellular enzymes was also specific activity on methyl ferulic acid, methyl caffeic acid and methyl p-coumaric acid respectively, but not methyl sinapinic acid, methyl vanillic acid and methyl gallic acid.