• Korean Journal of Microbiology
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• v.25 no.1
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• pp.17-22
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• 1987

For the purpose of securing of strains which can be usefully utilized to study symbiosis between Rhizobium and legume plant, A. tumefaciens T7 was isolated and characterized and then subgroup biovar was determined. A. tumefaciens T7 induced smooth tumor like nopaline type one and did not grow at $37^{\circ}C$ and in the presence of 2% NaCl on yeast extract mannitol medium. The strain was able to grow on the New and Kerr selective media and utilize erythritol but not phenylalanine, tryptophan, and tartarate as a sole carbon source. Negative results were obtained from 3-keto-lactose production and oxidase test. The strain produced alkalifrom malonate and citrate and showed acid litmus milk reaction At least two large plasmids were detected in the cell lysate. According to all of these results, it could be concluded that subdivision of isolated strain was biovar 2.

• Polymer(Korea)
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• v.28 no.4
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• pp.352-359
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• 2004

Membrane technology was used for the optical resolution of the various racemic compounds such as tryptophan, tyrosine and phenylalanine, using enantioselective membranes prepared from sodium alginate (SA) and glutaraldehyde as a membrane material and crosslinking agent, respectively, The chemical structure of the membranes was characterized with FT-IR spectrophotometry and 3D molecular structure modeling study was done to figure out the optical resolution mechanism through the membrane. Effects of degree of crosslinking, feed concentration, operating pressure and different kinds of feed solution on the membrane performances were studied. As results, it was found that with increasing degree of crosslinking and membrane thickness, and decrease in the concentration of the feed solution and smaller size of solutes, the enantinselectivity of the membrane was improved. When the sodium alginate membranes with 80% of swelling index and 79${\mu}{\textrm}{m}$ of thickness were used, 77% of enantiomeric excess was obtained.

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1290-1293
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• 2007

The nutritional composition of fruiting body of Sparassis crispa has been analyzed for medicinal and edible uses. Minerals in S. crispa were found to be as follows; potassium (1,299.44 mg), phosphorus (104.73 mg), sodium (98.21 mg), magnesium (54.86 mg), calcium (8.39 mg), iron (7.61 mg), zinc (6.37 mg), copper (1.31 mg) and manganese (0.63 mg) based on 100 g of mushroom dry weight. In 20 kinds of total amino acids found in S. crispa, sum of glutamic acid and glutamine content was the highest (1,960 mg/l00 g) and sum of aspartic acid and asparagine, tryptophan, leucine and alanine were followed. Concerning free amino acids, glutamic acid, tryptophan, glutamine and aspartic acid were dominant. Among 8 vitamins detected, the vitamin E content was the highest (408.5 mg) based on 100 g of mushroom dry weight, then vitamin C, niacin and pantothenic acid were followed.

• KSBB Journal
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• v.8 no.3
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• pp.193-199
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• 1993

To find out the optimum conditions for indigo cell culture in air-lift bioreactor, effects of media composition including nutrients and precursors of the indigo colorants on the cell growth and characteristics of the cell growth under various cultural conditions were analyzed. Optimum cultural conditions were tested and the growth characteristics were analyzed in external and internal loop type air-lift bioreactors during 14-day culture. Better cell growth was obtained when the inoculum size was higher in the range of 0.5∼2.5% packed cell volume tested. In the sucrose concentration of 2 to 4%, the cell growth was better when the sucrose concentration was 4% (w/w) in both types of reactors. Sucrose was used up in the early stage of exponential phase of growth At the optimum concentration of a Precursor tryptophan at 1 U UW was 3.8 g/l in internal loop bioreactor, and 3.5 g/l in external one after 14 days of cultivation. Addition of indole showed negative effect on cell growth of suspension culture in air-lift biorector culture and cell mass of 2.5 g/l and 2.2 g/l were obtained in external and internal loop bioreactor, respectively. Selected inorganic nitrogen source potassium nitrate showed about 110% increase in cell growth than that of control. DCW was 16.34 g/l under optimum conditions during 14-day cultivation in internal loop bioreactor.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.9
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• pp.1326-1333
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• 2002

Studies were conducted with nine barrows, average initial body weight $44.5{\pm}2.1kg$, fitted with a T-cannula at the distal ileum, to determine the apparent ileal (and true) digestibility (AID and TID) of CP and AA in different cultivars of rapeseed meals and soybean meal. The barrows were fed either a casein diet or one of eight corn starch-based semipurified diets, formulated to contain 17.0% CP (DM basis) with one of seven different cultivars of rapeseed meal or soybean meal as the sole source of dietary protein, according to a six-period, nine-treatment, incomplete Latin Square. Chromic oxide (0.5%) was used as a digestibility marker. The pigs were fed of 4% of body weight twice daily, at 08:00 and 20:00 h. Ileal digesta were collected at 2 h intervals daily from 5 d to 7 d. The AID or TID values of CP and most AA (Cysteine excluded) were significantly lower in the rapeseed meals than in soybean meal (p<0.05). There were significant differences in the AID or TID values of CP and AA among the seven different cultivars rapeseed meals (p<0.05); the seven rapeseed meals were arranged according to the size of the AA digestibility values of the rapeseed meals from the greatest to the least, as Zayou 59, Youyan 7, Ganyou 16, Qingyou 2, Huaza 3, Ningza 1 and Lianglou 586; differences in CP, AA, NDF and ADF contents in the rapeseed meals were mainly responsible for the variation in the AID or TID values of AA among rapeseed meals. The AID value of CP can be used as an index of the AID or TID values of most AA in rapeseed meals. However, the AID value of CP was less appropriate as a direct indicator of the AID or TID values for cysteine, methionine, tryptophan, phenylalanine and proline.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.305-311
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• 2001

Antifungal bacterium, Bacillus subtilis YS1 was isolated from Yusong hot spring showed broad antifungal spectrum against 12 kinds of plant pathogenic fungi and Candida albicans, animal pathogen. From the gamma($Co^{60}$) radiation sensitivity test, $D_10$ value was 2.08 kGy and it survived above 20 kGy of radiation dose. Several mutants were induced by gamma radiation. Among them, YS1-1009 mutant showed resistance against tebuconazole of herbicide, increased activity against Botryoshaeria dothidea and ligninase activity. YS67 mutant was antifungal deficient auxotrophic mutants(trp-pro-or arg-ura-). From this results, it suggested that gamma irradiation could be useful method for mutant induction.

• Microbiology and Biotechnology Letters
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• v.13 no.2
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• pp.119-127
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• 1985

A series of Escherichia coli mutants were exmined for ability to convert glucose and ammonium salts into phenylalanine. This enabled the biochemical changes having major. effects on phenylaianine yield, and interactions between mutations, to be identified. Changes to the common pathway of aromatic biosynthesis having a major effects include desensitization of the first enzyme (3-deoxy-D-arabinoheptulosonate synthase) to end-product inhibition, and removal of repression of enzyme synthesis. It is suggested that the 3-deoxy-D-arabino-heptulosonate synthase Phe isoenzyme has a more important effect on yield. Similarly, removal of repression and end-product inhibition on the phenylalanine terminal pathway increased yield, and changes to both common and branch pathways were synergistic. Blockage of the typrosine and tryptophan pathways had minor effects on phenylalanine yield, and a mutation affecting aramatic amino acid transport (aroP) decreased yield. With multiple-mutation strains hish specific rates of product formation (ie 0.1-0.17g phenylalanine/g cells/h) were obtained.

• Bulletin of the Korean Chemical Society
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• v.27 no.4
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• pp.549-555
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• 2006

Acetohydroxyacid synthase (AHAS, EC 2.2.1.6 also referred to as acetolactate synthase) catalyzes the first common step in the metabolic pathway leading to biosynthesis of the branched-chain amino acids in plants and microorganisms. Due to its presence in plants, AHAS is a target for the herbicides (sulfonylurea and imidazolinone), which act as potent inhibitors of the enzyme. Recently, we have shown [J. Kim, D.G. Baek, Y.T. Kim, J.D. Choi, M.Y. Yoon, Biochem. J. (2004) 384, 59-68] that the residues in the “mobile loop” 567-582 on the C-termini are involved in the binding/stabilization of the active dimer and ThDP (thiamin diphosphate) binding. In this study, we have demonstrated the role of the W573 in the mobile loop of the C-termini of tobacco AHAS. The substitution of this W573 residue caused significant perturbations in the activation process and in the binding site of ThDP. Position W573 plays a structurally important role in the binding of FAD, maintaining the enzyme active site in the required geometry for catalysis to occur. In here we propose that the tryptophan at position 573 is important for the catalytic process.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.13-22
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• 2003

Growth Hormone (GH) gene is a member of gene family through the evolutionary process from a small common ancestral gene by a series of gene duplications. The role of the GH in growth and performance controls has been extensively studied in human, mice and livestock. Many researchers have considered GH as a strong candidate gene for evaluation of genetic polymorphisms that could be associated with economic traits in cattle. We report here a novel missense mutation within the exon 5 of the bovine Growth Hormone (bGH) gene. We could amplified 522 bp fragments from eight unrelated Hanwoo cattle by PCR, then, subsequently cloned and sequenced. An Msp I RFLP corresponding to a C to T transition was observed at position 2258 nt. From this result, we could predict a missense mutation (Arg to Trp) at codon 166 in a highly conserved region among many mammals. Codominant Mendelian segregation of the two alleles, Msp I (+) and Msp I (－), was observed in two full-sib F2 families (n = 32, African taurine Bos taurus ${\times}$ African zebu Bos indicus) and eight half-sib Hanwoo families. For the availability of genetic marker, we have performed PCR-RFLP with a large number of individual animals from 15 different cattle breeds (European and Asian taurines, and African indicines). Consideration of breed frequencies of Msp I (－) allele in relation to breed type and their geographic origins, shows higher frequencies in humped breeds or Asian cattle breeds than in humpless or European breeds. This result indicates that the missense mutation can be contributed the functional significance such as the signal transduction through the receptor binding, also may be used as a marker for selection of the economic traits in Hanwoo.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.11
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• pp.1623-1628
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• 2011

The effects of dietary lysine (Lys) at a fixed ratio to crude protein (CP) and essential amino acids (EAA) on early growth response of broilers were studied. Four diets were formulated to contain similar metabolizable energy (ME, 2,950 kcal/kg) but contained graded levels of incremental Lys (1.1, 1.2, 1.3 and 1.4%) while also increasing the dietary CP and EAA (methionine, methionine+ cystine, threonine and tryptophan) to maintain a constant ratio with Lys. Each diet was fed at random to 10 replicates of 6 chicks each throughout the experimental period (1-21 d). At the lowest concentration of Lys of 1.1% (19.04% CP), body weight gain (BWG) was lowest and feed conversion ratio (FCR) was poorest. The BWG increased and FCR decreased linearly as dietary Lys increased upto 1.3% (22.5% CP). Lowest feed consumption was observed in the dietary group that contained 1.1% Lys (19.04% CP) in the diet. Increasing the concentration of Lys to 1.2% (20.77% CP), significantly increased the feed consumption. The concentrations of protein, calcium, phosphorus and cholesterol in serum were not influenced by the variation in Lys contents in the diet. The humoral immune response as measured by antibody titre in response to SRBC inoculation was significantly lower in the diets containing 1.1% Lys compared to 1.4%. It is concluded that the Lys requirement of broilers is 1.3% (22.5% CP) during 0 to 21 days of age for eliciting optimum performance when a fixed ratio of Lys to CP (1:17.31) and essential AA is maintained (1:0.47 Met; 1:0.56 Thr; 1:0.17 Try).