• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.473-474
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• 2013

• 대한미세수술학회:학술대회논문집
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• 1998.11a
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• pp.193-193
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• 1998

• Journal of Microbiology and Biotechnology
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• v.17 no.12
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• pp.2046-2055
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• 2007

Wild-type V. vulnificus cannot grow using lactose as the sole carbon source or take up the sugar. However, prolonged culture of this species in media containing lactose as the sole carbon source leads to the generation of a spontaneous lactose-utilizing (LU) mutant. This mutant showed strong ${\beta}$-galactosidase activity, whereas the wild-type strain showed a barely detectable level of the activity. A mutant with a lesion in a gene homologous to the lacZ of E. coli in the bacterium no longer showed ${\beta}$-galactosidase activity or generated spontaneous LU mutants, suggesting that the lacZ homolog is responsible for the catabolism of lactose, but the expression of the gene and genes for transport of lactose is tightly regulated. Genetic analysis of spontaneous LU mutants showed that all the mutations occur in a lacI homolog, which is located downstream to the lacZ and putative ABC-type lac permease genes. Consistent with this, a genomic library clone containing the lad gene, when present in trans, made the spontaneous LU mutants no longer able to utilize lactose as the sole carbon source. Taken together with the observation that excessive amounts of exogenously supplemented possible catabolic products of lactose have negative effects on the growth and survivability of V. vulnificus, we suggest that V. vulnificus has evolved to carry a repressor that tightly regulates the expression of lacZ to keep the intracellular toxic catabolic intermediates at a sublethal level.

• Preventive Nutrition and Food Science
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• v.13 no.1
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• pp.7-11
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• 2008

To improve the utilization of fish processing by-products, fish oils were extracted from hoki, yellowfin sole, mackerel, and horse mackerel, and their compositions were examined. The proximate compositions obtained for these 4 species of by-product revealed they were composed of 68.1$\sim$78.1% moisture, 1.2$\sim$1.6% ash, and 13.8$\sim$18.8% protein. Fish oils extracted from the hoki, yellowfin sole, mackerel, and horse mackerel were 5.5, 9.4, 13.4, and 10.3%, respectively. The total lipids extracted from the by-products of the 4 species were 6.21, 10.43, 12.81 and 10.06%, of which neutral lipids accounted for 77.38, 77.46, 87.21 and 86.79%, respectively. Neutral lipid analysis by TLC showed that triacylglycerol was the major component, while 1,3- and 1,2-diacylglycerols, free fatty acids, free sterols, and sterol esters were present as minor components. The major fatty acids were palmitic acid, stearic acid, and oleic acid. DHA and EPA were contained at levels of 0.2$\sim$4.7% and 3.7$\sim$9.5%, respectively, in the 4 types of fish oil. The fish oils extracted from the dark muscle fish, mackerel and horse mackerel, had greater polyunsaturated fatty acid (PUFA) contents than those of the white muscle fish species, hoki and yellowfin sole.

• Journal of Microbiology and Biotechnology
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• v.20 no.8
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• pp.1196-1203
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• 2010

In the present work, methanethiol and dimethyldisulfide were investigated as sulfur sources for methionine synthesis in Corynebacterium glutamicum. In silico pathway analysis predicted a high methionine yield for these reduced compounds, provided that they could be utilized. Wild-type cells were able to grow on both methanethiol and dimethyldisulfide as sole sulfur sources. Isotope labeling studies with mutant strains, exhibiting targeted modification of methionine biosynthesis, gave detailed insight into the underlying pathways involved in the assimilation of methanethiol and dimethyldisulfide. Both sulfur compounds are incorporated as an entire molecule, adding the terminal S-$CH_3$ group to O-acetylhomoserine. In this reaction, methionine is directly formed. MetY (O-acetylhomoserine sulfhydrylase) was identified as the enzyme catalyzing the reaction. The deletion of metY resulted in methionine auxotrophic strains grown on methanethiol or dimethyldisulfide as sole sulfur sources. Plasmid-based overexpression of metY in the ${\Delta}$metY background restored the capacity to grow on methanethiol or dimethyldisulfide as sole sulfur sources. In vitro studies with the C. glutamicum wild type revealed a relatively low activity of MetY for methanethiol (63 mU/mg) and dimethyldisulfide (61 mU/mg). Overexpression of metY increased the in vitro activity to 1,780 mU/mg and was beneficial for methionine production, since the intracellular methionine pool was increased 2-fold in the engineered strain. This positive effect was limited by a depletion of the metY substrate O-acetylhomoserine, suggesting a need for further metabolic engineering targets towards competitive production strains.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.532-539
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• 2004

For efficient lincomycin production from Streptomyces lincolnensis L1245, various vegetable oils, natural nitrogen sources, and surfactants were investigated at the pilot-scale level in the flask. Olive oil as the sole carbon source was the most suitable one for producing lincomycin. When 20 g/lof olive oil was used, the lincomycin concentration and lipase activity reached 1.01 g/land 182 U/ml, respectively, after 5 days of culture. Among the various unsaturated fatty acids, when linolenic acid was used, the cell growth and lincomycin production were markedly decreased. On the other hand, when 0.2 g/l of oleic acid was added to the culture broth, the maximum lincomycin concentration was 1.0 g/l, which was about 1.7-fold higher than that obtained without the addition of oleic acid. Among the various natural nitrogen sources, pharmamedia or soybean meal was the most suitable nitrogen source. In particular, in the case of a mixture of 10 g/l of pharmamedia and soybean meal, 1.5 g/l of lincomycin concentration and 220 U/ml of lipase activity were obtained. When Span 180 was used as the surfactant, lincomycin production, lipase activity, and oil consumption increased. The correlation between the consumption rates of oil and lincomycin production in a culture using olive oil as the sole carbon source was also investigated. The lincomycin production depended on the consumption rate of olive oil. Using these results, fed-batch cultures for comparing the use of olive oil and starch as a conventional carbon source were carried out in a 5-1 fermentor. When olive oil was used as the sole carbon source, 34 g/l of olive oil was consumed after 7 days of culture. The maximum lincomycin concentration was 3.0 g/l, which was about 2.0-fold higher than that of starch medium after 7 days of culture. The product yield was 0.09 gig of consumed carbon source, which was about 3.0-fold higher than that of starch medium after 7 days of culture.

• Journal of Microbiology and Biotechnology
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• v.22 no.9
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• pp.1230-1236
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• 2012

Fish meal grades SL1 and SL2 from Sardine (Sardinella longiceps) and NJ from Pink Perch (Nemipterus japonicas) were evaluated as a sole source of carbon and nitrogen in the medium for alkaline protease production by Bacillus pumilus MTCC 7514. The analysis of the fish meal suggests that the carbon and nitrogen contents in fish meal are sufficient to justify its choice as replacement for other nutrients. Protease production increased significantly (4,914 U/ml) in medium containing only fish meal, compared with the basal medium (2,646 U/ml). However, the elimination of inorganic salts from media reduced the protease productivity. In addition, all the three grades of fish meal yielded almost the same amounts of protease when employed as the sole source of carbon and nitrogen. Nevertheless, the best results were observed in fish meal SL1 medium. Furthermore, protease production was enhanced to 6,966 U/ml and 7,047 U/ml on scaling up from flask (4,914 U/ml) to 3.7 and 20 L fermenters, respectively, using fish meal (10 g/l). Similarly, the corresponding improvement in productivities over flask (102.38 U/ml/h) was 193.5 and 195.75 U/ml/h in 3.7 and 20 L fermenters, respectively. The crude protease was found to have dehairing ability in leather processing, which is bound to have great environmental benefits.

• Nuclear Engineering and Technology
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• v.1 no.1
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• pp.17-22
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• 1969

English sole (Parophrvs vetulus) fillets packaged in polymylar bags were irradiated at 500 Krad, using a Cobalt-60 irradiator and the accumulation of spoilage indices substances and bacterial growth in the irradiated and unirradiated samples were measured during 36 days of storage at 0-2$^{\circ}C$. A casein agar plate technique was developed for a direct enumeration of proteolytic bacterial population, thus enabling the determination of relative proportion of proteolytic bacteria in the total microflora at each storage interval. Irradiation at 500 Krad resulted in a ten fold reduction of microflora and throughout the storage period the level of microflora lagged behind that of the unirradiated, by as much as one thousand fold. This was accompanied by a remarkable suppression of TVB and TMA accumulation in the irradiated, never reaching a spoliage level. Proteolytic bacterial population also was reduced to below one per cent of the total viable count and remained so throughout the storage period, while proteolytic bacteria in the unirradiated increased proportionately with the storage, comprising 85.5% of the total microflora by the twenty-second day. This selective removal of proteolytic bacteria must account for the reduced rate of proteolysis occurred in the irradiated during the storage.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.847-853
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• 1999

A Pseudomonas sp. strain that is capable of utilizing dicarboxylic acids as a sole carbon source was isolated from activated sludge by using the enrichment culture technique. This organism accumulated polyhydroxyalkanoates (PHAs) with an unusual pattern of monomer units that depends on the carbon sources used. Polyhydroxybutyrate (PHB) homopolyester was synthesized from glucose or small $C_{-even}$ alkanoic acids, such as butyric acid and hexanoic acid. Accumulation of PHB homopolyester was also observed in the cells grown on $C_{-odd}$ dicarboxylic acids, such as heptanedioic acid and nonanedioic acid as the sole carbon sources. In contrast, a copolyester consisting of 6 mol% 3-hydroxybutyrate (3HB) and 94 mol% 3-hydroxyvalerate (3HV) was produced with a PHA content of as much as 36% of the cellular dry matter. This strain produced PHAs consisting both of the short-chain-length (SCL) and the medium-chain-length (MCL) 3-hydroxyacid units when heptanoic acid to undecanoic acid were fed as the sole carbon sources. Most interestingly, polyester consisting of significant amount of relevant fractions, 3HB, 3HV, and 3-hydroxyheptanoate (3HHp), was accumulated from heptanoic acid. According to solvent fractionation experiments, the polymer produced from heptanoic acid was a blend of poly(3HHp) and of a copolyester of 3HB, 3HV, and 3HHp units. The hexane soluble fractions contained only 3HHp units while the hexane-insoluble fractions contained 3HB and 3HV units with a small amount of 3HHp unit. The copolyester was an elastomer with unusual mechanical properties. The maximum elongation ratio of the copolyester was 460% with an ultimate strength of 10 MPa, which was very different from those of poly(3HB-co-3HV) copolyesters having similar compositions produced from other microorganisms.

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.3
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• pp.305-320
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• 2014

This study identifies the foot shapes of elderly women by classifying foot type according to the 3D shape of the foot and 2D sole type analyzing individual characteristics. The subjects were 295 elderly women over 60 years of age who live in Gwangju. A foot scanner (K&I Technology $Nexcan^{(R)}$) was used to obtain three-dimensional shapes of feet and a flat bad scanner (HP Scanjet G2410) was used to obtain the two-dimensional shapes of soles. The anthropometric measuring items consisted of 59 items estimated on the right foot of each subject. Data were analyzed by various statistical methods such as factor analysis, ANOVA and cluster analysis using the SPSS 19.0 statistical program. To classify the side type of elderly women's feet, three-dimensional measurement data were analyzed for the 27 measurement items using factor analysis and 6 factors were extracted (inside height and side gradient, ankle thickness, toe height and midfoot size, lateral malleolus height, instep, and heel height and gradient). A cluster analysis resulted in three types: 36.5% belonged to Type 1 (high forefoot and high midfoot), 31.1% belonged to Type 2 (high forefoot and low midfoot), and 32.4% belonged to Type 3 (low forefoot and high midfoot). The distribution was relatively even. For the sole, 8 factors were extracted (ball width and medial foot protrusion, lateral foot protrusion, forefoot and hindfoot length ratio, ball gradient, heel size, toe breadth, lateral ball length, and foot length) and a cluster analysis resulted in three Types (Type H, Type D, and Type A). The largest proportion (42.7%) belonged to Type H, which is the same as the elderly men's case.