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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Microbiology and Biotechnology
Journal Basic Information
Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
Editor in Chief :
Volume & Issues
Volume 9, Issue 6 - Dec 1999
Volume 9, Issue 5 - Oct 1999
Volume 9, Issue 4 - Aug 1999
Volume 9, Issue 3 - Jun 1999
Volume 9, Issue 2 - Apr 1999
Volume 9, Issue 1 - Feb 1999
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Novel Heterogeneous Carbohydrase Reaction Systems for the Direct Conversion of Insoluble Carbohydrates: Reaction Characteristics and their Applications
Lee, Yong-Hyun ; Park, Dong-Chan ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 1~8
Most carbohydrates exist in nature in an insoluble state, which reduces their susceptibility towards various carbohydrases. Accordingly, they require intensive pretreatment for structural modification to enhance an enzyme reaction. The direct conversion of insoluble carbohydrates has distinct advantages for special types of reaction, especially exo-type carbohydrase; however, its application is limited due to structural constraints. This paper introduces two novel heterogeneous enzyme reaction systems for direct conversion of insoluble carbohydrates; one is an attrition coupled enzyme reaction system containing attrition-milling media for enhancing the enzyme reaction, and the other is a heterogeneous enzyme reaction system using extruded starch as an insoluble substrate. The direct conversion of typically insoluble carbohydrates, including cellulose, starch, and chitin with their corresponding carbohydrases, including cellulase, amylase, chitinase, and cyclodextrin glucanotransferase, was carried out using two proposed enzyme reaction systems. The conceptual features of the systems, their reaction characteristics and mechanism, and the industrial applications of the various carbohydrates are analyzed in this review.
Cyanobacterial Toxins: The Current Status
Tyagi, M.B. ; Thakur, J.K. ; Singh, D.P. ; Kumar, Arvind ; Prasuna, E.G. ; Kumar, Ashok ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 9~21
Improvement of Kimchi Fermentation by Using Acid-Tolerant Mutant of Leuconostoc mesenteroides and Aromatic Yeast Saccharomyces fermentati as Starters
Kim, Young-Chan ; Jung, Eun-Youg ; Kim, Hyung-Joo ; Jung, Dai-Hyun ; Hong, Seong-Gil ; Kwon, Tae-Jong ; Kang, Sang-Mo ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 22~31
Saccharomyces fermentati and Leuconostoc mesenteroides were isolated from a traditional kimchi, and then the Leu. mesenteroides was mutated to the acid-tolerant mutant Leu. mesenteroides M-l00. In the result of growth properties in MRS broth with various pHs adjusted with HCl and acid solution (latic acid:acetic acid=1:2), an acid-tolerant mutant Leu. mesenteroides M-100 showed more increased ability for growth than its wild strain at various temperatures. The strains were used as starters for the fermentation of kimchi. The experiments were performed with classified experimental groups (Group I, control kimchi; Group II, addition of YK-19 only; Group III, addition of M-100 only; Group IV, addition of mixture of M-100 and YK-19), and their pH, total acidity, reducing sugars content, organic acid productivity, organoleptic tests, and microfloral changes were compared. As a result, in pH and acidity, the optimal ripening period of Group IV was about 13.5 days (i.e. from the 8.5 to 22 days of fermentation). This result indicates that the optimal ripening period of Group IV was about 1.5 times longer than that of Group I. Furthermore, Group IV was edible to 28 days of fermentation. In addition, high contents of succinc acid was observed in Group IV. Group IV was also highly ranked on the organoleptic test. During the fermentation of kimchi, the number of Leuconostoc sp. in group I reduced after 7 days; however, the number of Leuconostoc sp. in Group II, III, and IV decresed after 14 days of fermentation. An especially high number of Leu. sp. was observed in Group IV, and this gave better flavor of kimchi than any other during the whole fermentation period. Citric acid, tartaric acid, succinic acid, fumaric acid, and lactic acid were detected in the kimchi, and a significant increase in the concentration of lactic acid during fermentation was observed in the all experimental groups.
Purification and Characterization of Biosurfactant from Tsukamurella sp. 26A
Choi, Kyung-Suk ; Kim, Soon-Han ; Lee, Tae-Ho ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 32~38
A biosurfactant produced by Tsukamurella sp. 26A was purified by procedures including acid precipitation, ethylacetate extraction, and adsorption chromatography. The purified biosurfactant reduced the surface tension of water from 72 mN/m to 30 mN/m at a concentration of 250 mg/l, whereas the minimum interfacial tension against n-hexadecane was lowered to 1.5 mN/m at a concentration of 40 mg/i. The compound stabilized oil-in-water emulsions with a variety of commercial oils and had strong emulsification and stabilization activities when compared to those of commercial emulsifiers and stabilizers. Surface tension was stable over a broad range of pH (2-12) and temperature (
, 3h). The biosurfactant was identified as glycolipid having a hydrophilic moiety of trehalose.
10-Hydroxyoctadecanoic Acid Produced by Lactococcus lactis subsp. lactis as a Part of Flocculent Aggregate
Park, Hee-Jun ; Lim, Yoong-Ho ; Kim, Youn-Soon ; Kyung, Kyu-Hang ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 39~43
A flocculent aggregate produced by Lactococcus lactis subsp. lactis in broths containing Tween 80, including MRS broth, had a microscopic structure of intertwined thread-like filaments. The filamentous structure was not elongated bacterial cells, but consisted of an organic solvent-soluble portion and an insoluble solid. L. lactis subsp. lactis grown at
for 15 days in tryptic soy broth with 0.1% Tween 80 and 1.0% malt extract produced 13 mg/l of flocculent aggregate, which contained 0.84 g/g of organic solvent-soluble component. The organic solvent-soluble part was identified as 10-hydroxyoctadecanoic acid.
Cellulase Production in Fed-Batch Culture by Trichoderma reesei Rut C30
Yu, Xiao-Bin ; Yun, Hyun-Shik ; Koo, Yoon-Mo ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 44~49
Cellulase production by fed-batch cultivation of Trichoderma reesei Rut C30 with various initial concentrations of Solka Floc in 1 % wheat bran-containing medium was investigated. The cellulase activity and productivity increased with initial Solka Floc concentration up to 5%. When a total Solka Floc concentration of 90 g/l was used for cellulase production, CMC (carboxymethyl cellulose) and FP (filter paper) activities, productivity, and yield were 359.7 U/ml, 30.61 U/ml, 161 FPU
, and 340 FPU
, respectively. It was important to maintain a high cell concentration during cellulase production to obtain high cellulase activity and productivity. Cellulase powder was prepared by ammonium sulfate precipitation: FP activity was 396.7 U/g and CMC activity was 6481 U/g.
Preparation of Nanoparticles in Drug Delivery System Using Guar Derivatives and Dialysis Method
Na, Kun ; Kim, Yu-Eun ; Lee, Ki-Young ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 50~55
To develop a new form of controlled release dosage for administering for indomethacin (IND), two formulations of IND-loaded nanoparticles were designed based on polysaccharide (guar) derivatives. Nanoparticles prepared by the dialysis method were characterized with respect to morphology, size distribution, drug content, and in vitro drug release. Morphological studies by scanning electron microscopy (SEM) indicated that guar acetate (GA) nanoparticles were spherical in shape and had a smooth surface. The particle size distributions of formulation I (40mg of GA) and formulation II (80mg of GA) were shown to be
in distilled water (
), respectively. The drug loading efficiencies of nanoparticles were approximately 26% and 31% for formulations I and II, respectively. The differential scanning calorimetry (DSC) results indicated that the IND was perfectly distributed within GA nanoparticles. We also found, from the X-ray diffractometry analysis, that a decrease in the degree of crystallinity of the drug occurred in the nanoparticles. No changes between the original IND and the released IND from GA nanoparticles were detected by FT-IR. Using guar acetate, it is possible to design nanoparticles which allow the controlled release of IND over an extended period of time.
Purification and Characterization of Biosurfactants Produced by Pseudomonas sp. SW1
Suk, Wan-Su ; Son, Hong-Joo ; Lee, Geon ; Lee, Sang-Joon ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 56~61
Pseudomonas sp. SW1 grew and produced biosurfactants on 3% hexadecane as the energy and carbon source. As a result of biosurfactant synthesis, the surface tension of the medium was reduced from 72 dyne/cm to 30 dyne/cm. The properties of biosurfactants that were purified from Pseudomonas sp. SW1 were investigated. The purification procedure included acid precipitation from culture supernatant, silica gel G60 column chromatography, and Sephadex G-150 gel filtration. The biosurfactants were separated into two different types, viz., types I and II. Biosurfactant type Isignificantly reduced the surface tension of water from 72 to 27 dyne/cm at concentration levels above 30 mg/l. The surface tension of water was reduced to a minimum of approximately 30 dyne/cm by biosurfactant type II at concentration levels over 80 mg/l. The biosurfactants were effective in a wide range of pHs, at NaCl concentrations of up to 4%, at
concentration up to 100 mM, and at temperatures up to
for 8 h.
The Roles of Tryptophan and Histidine Residues in the Catalytic Activities
-Cyclodextrin Glucanotransferase from Bacillus firmus var. alkalophilus
Shin, Hyun-Dong ; Kim, Chan ; Lee, Yong-Hyun ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 62~69
In order to investigate the critical amino acid residues involved in the catalytic activities of
-cyclodextrin glucanotransferase (
-CGTase) excreted by Bacillus firmus var. alkalophilus, the amino acid residues in
-CGTase were modified by various site-specific amino acid modifying reagents. The cyclizing and amylolytic activities of
-CGTase were all seriously reduced after treatment with Woodward's reagent K (WRK) modifying aspartic/glutamic acid, N-bromosuccinimde (NBS) modifying tryptophan, and diethylpyrocarbonate (DEPC) modifying histidine residues. The roles of tryptophan and histidine residues in
-CGTase were further investigated by measuring the protection effect of various substrates during chemical modification, comparing protein mobility in native and affinity polyacrylamide gel electrophoresis containing soluble starch, and comparing the
values of native and modified enzymes. Tryptophan residues were identified as affecting substrate-binding ability rather than influencing catalytic activities. On the other hand, histidine residues influenced catalytic ability rather than substrate-binding ability, plus histidine modification had an effect on shifting the optimum pH and pH stability.
Effect of Environmental Stress on Morphological Change of an Extremely Cadmium-Tolerant Yeast, Hansenula anomala B-7
Huh, Nam-Eung ; Choi, Nack-Shick ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 70~77
An extremely cadmium-tolerant budding yeast, Hansenula anomala B-7 underwent a morphological switch in response to either heat shock treatment or cadmium stress, respectively. It exhibited a morphological transition from a unicellular yeast form to a pseudohyphae-like coagulation when subjected to prolonged heat shock treatment. In contrast, the yeast cells showed an irregularity in surface morphology when given thermal stress for a short time. Patterns of proteins expressed in the pseudohyphae-like cells demonstrated that several proteins were overexpressed while others were underexpressed in comparison with those prepared from the cells in the yeast form. It was a striking feature, however, that nearly 40％ of the proteins extracted from the cells in the pseudohyphae form appeared to be composed of a single polypeptide. This polypeptide was apparently overexpressed during the pseudohyphae phase and its molecular weight was estimated to be 58 kDa according to SDS-PAGE analysis. However, a significant level of the protein was not observed in the cells before transition to pseudohyphae. The architecture of the cell shape was also damaged when incubated in a medium containing more than 1,000 ppm (8.9mM) of cadmium ions, although able to proliferate at a slow rate. However, the irregularity in the cell morphology exerted either by the brief heat shock treatment or by the cadmium stress with the high concentrations of the metal ions was not repaired, even though the damaged cells were allowed to grow for sufficient time in fresh, cadmium-free medium.
Intraspecific Variation of Environmental and Clinical Vibrio vulnificus Isolates as Demonstrated by Restriction Endonuclease Digestion Profiles
Kim, Ki-Yong ; Yang, Ho-Chul ; Tamplin, Mark-L. ; Choi, Sang-Ho ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 78~83
Thirty-six environmental isolates of Vibrio vulnificus obtained from seawater, sediments, and raw seafoods, and 18 clinical isolates from Vibrio septicemia patients were typed by restriction endonuclease digestion profiles (REDP) of genomic DNA with SfiI. The results revealed a high-level of variation in REDPs, indicating a vast genomic diversity among V. vulnificus strains. Genetic relatedness of the strains showed similarities ranging from 10％ to 100％. Different REDPs for isolates from various raw seafoods were obtained, and clustering of strains according to type of seafoods was not observed. In contrast, clinical isolates of V. vulnificus showed higher similarity to one another, and could be subdivided into one separate group. The difference in REDPs of the V. vulnificus isolates from clinical origin and from raw seafoods substantiates the previous observation that only a single type of pathogenic strain was involved in each human infection, despite the numerous genetically polymorphic strains found from implicated oysters.
Isolation and Characterization of Lactate-Tolerant Mutants in Bifidobacterium breve
Hyun, Hyung-Hwan ; Lee, Hyune-Hwan ; Yeo, Ick-Hyun ; Kim, Tae-Seok ; Lee, Joo-Hee ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 84~90
The growth of Bifidobacterium breve strain HP2 was completely inhibited by the addition of lactate higher than 4.0％ but not by the addition of acetate. Two kinds of lactate-tolerant mutants were isolated by the nitrosoguanidine treatment, enrichment on a liquid medium with 5％ lactate, and selection on agar plates with 5％ lactate. The mutants were not only able to grow in the presence of 5％ lactate but also improved in viable cell stability in the acidic pH range. In a pH-controlled fermentor, mutant N-1-5 grew at a rate slower than that of the wild type but its growth yield was higher. Notably, mutants were more halotolerant and more osmotolerant than the wild type and they were able to grow in the presence of 3％ NaCl or 25％ lactose at which the wild type entirely stopped the growth. The enzyme activities involved in the lactose metabolism in B. breve were measured to elucidate the biochemical basis for lactate tolerance. In the mutants, activities of several enzymes including phosphoglucomutase decreased compared to the wild-type, which may explain their lower growth rate. However, the activity of lactate dehydrogenase or its nature of inhibition by lactate was not altered.
Characterization of the Replication Region of the Enterococcus faecalis Plasmid p703/5
Song, Joon-Seok ; Park, Jin-Hwan ; Kim, Chan-Wha ; Kim, Young-Woo ; Lim, Wang-Jin ; Kim, Ick-Young ; Chang, Hyo-Ihl ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 91~97
In this work, a 1.9-kb region of enterococcal plasmid p703/5 was isolated and the nucleotide sequence analysis of the region was performed. One major open reading frame (ORF) was identified encoding a polypeptide of 28 kDa. Database comparisons suggested that the protein showed some homology with other bacterial RepA proteins. Upstream of the ORF, a potential dnaA box, AT-rich region and 22-bp tandemly repeated sequences (DNA iterons), a feature typical for many replication ori sites, were recognized. Deletion analysis using Exonuclease III and several restriction enzymes indicated that the three elements and the gene product from the ORF were essential for replication and that the minimum unit of DNA required for replication resided on the 1.2-kb AvaII subfragment. Thus, this gene product was referred to as RepA.
Comparison of Nitric Oxide, Hydrogen Peroxide, and Cytokine Production in RAW 264.7 Cells by Bifidobacterium and Other Intestinal Bacteria
Om, Ae-Son ; Park, So-Young ; Hwang, In-Kyeong ; Ji, Geun-Eog ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 98~105
Intestinal bacteria comprise one-third of the contents of the large intestine in humans. Their interactions with the gastrointestinal immune system induce characteristic immunological responses which stimulate or suppress the host's defense system. RAW 264.7 murine cell line was used as a macrophage model to assess the effects of the exposure to the isolated human intestinal bacteria, Bacteroides, Bifidobacterium, Eubacterium, Streptococcus, and E. coli, on NO (nitric oxide),
(hydrogen peroxide), and cytokines IL (interleukin)-6 and TNF (tumor necrosis factor)-a production. RAW 264.7 cells were cultured in the presence of heat-killed bacteria for 24 h at concentrations of 0-
g/ml. Our results showed that Bacteroides and E. coli stimulated IL-6, TNF-
, NO, and
production at high levels even at
g/ml, whereas Bifidobacterium, Eubacterium, and Streptococcus showed a low level of stimulation at
g/ml, and a gradual increase as the cell concentration increased up to
g/ml. This result suggests that gram-negative Bacteroides and E. coli are better able to stimulate macrophage than gram-positive Bifidobacterium, Streptococcus, and Eubacterium. The in vitro approaches employed here should be useful in further characterization of the effects of intestinal bacteria on gastrointestinal and systemic immunity.
Newly Synthesized Phosphodiesterase 4 (PDE4) Inhibitor, DWP205505, Inhibits TNF-
Secretion and mRNA Expression
Lee, Suk-Kyeong ; Lee, Sun-A ; Byun, Hye-Sin ; Cho, Mi-La ; Kim, Wan-Uk ; Park, Sung-Hwan ; Cho, Chul-Soo ; Joo, Young-Shil ; Lee, Shin-Seok ; Yoo, Eun-Sook ; Son, Ho-Jung ; Kim, Ho-Youn ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 106~112
The therapeutic potential of phosphodiesterase 4(PDE4) inhibitors in inflammatory diseases including some autoimmune diseases has been explored recently with some hopeful results. These PDE4 inhibitors are thought to show their anti-inflammatory effect by down-regulating tumor necrosis factor-a (TNF-
) production in lymphocytes and macrophages. A high concentration of TNF-
has been found in rheumatoid arthritis (RA) synovium and reducing TNF-
using biological agents was proven to be an effective RA treatment. To test the possibility of using PDE4 inhibitors for RA treatment, the effects of a newly synthesized PDE4 inhibitor, DWP205505, on TNF-
and IL-10 production was tested in cells isolated from normal peripheral blood and rheumatoid arthritis synovial fluid. Cytokine production was assayed at the protein level by sandwich enzyme-linked immunosorbent assay (ELISA) and at the mRNA expression level by semi-quantitative RT-PCR. Another PDE4 inhibitor, RP73401, was used for comparison. DWP205505 and RP73401 had no harmful effect on cell viability up to 10
M concentration during the 24 h culture period. DWP205505 as well as RP73401 significantly reduced TNF-
secretion from lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (pBMC) and synovial fluid mononuclear cells (SFMC). The effect of DWP205505 or RP73401 treatment on the mRNA expression of TNF-
was also studied in LPS-stimulated PBMC and SFMC. TNF-
mRNA expression was increased by LPS stimulation and both of the PDE4 inhibitors suppressed TNF-
mRNA expression. For interleukin-l0 (IL-l0), a little different results were obtained from PBMC and SFMC; IL-l0 secretion was unaffected by LPS stimulation and only minimally affected by both of the PDE4 inhibitors in PBMC. In unstimulated SFMC, DWP205505 and RP73401 slightly enhanced IL-10 secretion, while they reduced IL-l0 secretion from LPS-stimulated SFMC where IL-l0 secretion was a lot higher than unstimulated SFMC. These results suggest that the newly synthesized PDE4 inhibitor DWP205505 may have anti-rheumatoid arthritis activity.
Identification of an Embryonic Growth Factor IGF-II from the Central Nervous System of the Teleost, Flounder, and Its Expressions in Adult Tissues
Kim, Dong-Soo ; Kim, Young-Tae ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 113~118
The insulin-like growth factor (IGF) is found in all vertebrates and its type-II molecule is regarded as a fundamental embryonic growth factor during development. We have firstly identified, in this study, a cDNA clone corresponding to IGF-II (flIGF-II) from the adult brain of the teleost, Paralichthys olivaceus. We also examined the tissue expression of flIGF-II in several adult tissues by RT-PCR. The flIGF-II cDNA contained a complete ORF consisting of 215 amino acids and one stop codon. Its molecular characteristics appear to be similar to the previously identified IGF-II molecules, in which a common primary structure exhibiting B, C, A, D, and E domains is evidently observed. This cDNA clone seems to be cleaved at
-end signal peptide and appears to produce a 98 amino acid-long E-peptide from the
. The functional B-D domain regions, therefore, include 65 amino acids and is able to encode a 7.4-kDa protein. The most prominent structural difference between IGF-I and IGF-II was that the D domain of IGF-II exhibits a two-codon-deleted pattern compared to the 8 amino acid-containing IGF-I. The insulin family signature in the A domain and six cysteins forming three disulfide bridges between the B and A domains were evolutionary-conserved from teleosts to mammalian IGF-II. Interestingly, the E-peptide region appears to provide a distinct hallmark between teleosts in amino acid composition. The flIGF-II shows 85.1% of sequence identity to salmon and trout, 90.6% to tilapia, and 98.4% to perch in amino acid level. In tissue expressions of IGF-II, it is very likely that flIGF-II has a significant expression in the adult brain. However, liver seems to be the main source for IGF-II production, and relatively low signals were observed in the adult muscle and kidney. Taken together, it would be concluded that the functional region for IGF-II mRNA is highly similar in phylogeny and is evolutionary, conserved as a mediator for the growth of vertebrates.
Sesquicillin, an Extracellular Matrix Adhesion Inhibitor, Inhibits the Invasion of B16 Melanoma Cells In vitro
Lee, Ho-Jae ; Chun, Hyo-Kon ; Chung, Myung-Chul ; Lee, Choong-Hwan ; Kho, Yung-Hee ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 119~121
Tumor cell interaction with the extracellular matrix is defined as the critical event of tumor invasion that signals the initiation of a metastatic cascade. Sesquicillin has been identified as an inhibitor of melanoma cell adhesion to the components of the extracellular matrix (ECM) in cultured broth of fungal strain F60063. Sesquicillin strongly inhibited the adhesion of B16 melanoma cells to laminin, fibronectin, and typeIV collagen. It also inhibited B16 melanoma cell invasion of reconstituted basement membrane Matrigel in vitro in a dose-dependent manner. These results suggest that sesquicillin is a new class of nonpeptidic ECM adhesion inhibitor having anti-invasive activity.
Site-Directed Saturation Mutagenesis of Yeast Gcn4p at Codon 242
Lee, Jae-Yung ; Bae, Yu-Byung ; Kim, Jung-Ae ; Song, Jae-Mahn ; Choe, Mu-Hyeon ; Kim, Ick-Young ; Kim, Joon ;
Journal of Microbiology and Biotechnology, volume 9, issue 1, 1999, Pages 122~125
Gcn4p, a transcriptional activator protein of the yeast, Sacchromyces cerevisiae, binds to the specific sequence in the promoters of many amino acid biosynthetic genes for general control. The serine residue (Ser 242) of Gcn4p directly contacts the DNA. Here, for inspecting the DNA binding properties and the level of transcriptional activation of Gcn4p, we introduced a polymerase chain reaction (PCR) site-directed saturation mutation library into the Ser 242 site using 2 outside primers and 2 oligonucleotides with its codons fully degenerated. The sequencing analysis of 146 samples revealed the even nucleotide distribution within the experimental error showing 23, 26, 25, and 26％ frequency of U, C, A, and G bases, respectively. This method turned out to be a simple, fast, and economical method for constructing a library of all 20 amino acids at specific codon.