Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Microbiology and Biotechnology Letters
Journal Basic Information
Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
Editor in Chief :
Volume & Issues
Volume 26, Issue 6 - Dec 1998
Volume 26, Issue 5 - Oct 1998
Volume 26, Issue 4 - Aug 1998
Volume 26, Issue 3 - Jun 1998
Volume 26, Issue 2 - Apr 1998
Volume 26, Issue 1 - Feb 1998
Selecting the target year
Ethylene Biosynthesis of an Alkalophilic Bacillus sp. Alk-7
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 195~199
AH alkalophilic Bacillus SP. AIk-7, isolated from soil, produced ethylene. The characteristics of this microorganism is the ability to grow well under the alkaline condition, at pH 10.3. This strain is similar to Bacillus alkalophilus in terms of morphological, physiological and biological characteristics. In observation of relationship of cell growth and ethylene production according to incubation times, the ethylene synthesis mostly occur from the late exponential phase to the death phase of growth. The purpose of this paper is to study the effects of various substrates on the biosynthesis of ethylene in the intact cell and the cell-free system by the Bacillus sp. AIk-7. In both intact cell and cell-free extract, optimum conditions for ethylene production was achieved at pH 10.3 and 3
. Ethylene was effectively produced from L-Met and 1-aminocyclopropane-1-carboxylic acid (ACC). In this case, ACC as the substrate on ethylene production were two fold higher than L-met at each concentration of substrates. On the other hand, the cell-free ethylene-forming system was used as a tool for the elucidation of the biochemical reaction involved in the formation of ethylene by Bacillus sp. AIk-7. Ethylene production in the cell-free system required the presence of manganese and cobalt ion to be stimulated a little. The result obtained in this work suggests that L-met and ACC may be a precursor more directly related to bacterial ethylene production than any other substrates tested.
Optimization of Freeze-drying Conditions for Probiotics Production with Animal Blood Proteins Added Medium.
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 200~205
A probiotic-strain of Lactobacillus sp. was cultured in bovine blood plasma-based (BBPB) medium and freeze-dried to prepare a probiotic product as an animal feed additive. The cell mass produced in the medium,
CFU/ml, was high enough to be commercialized and was 74% of that in MRS medium. The survival rate of tactobacillus sp. against freeze-drying was affected by the conditions for treatment of cultured BBPB broth before freeze-drying such as pH adjustment, volume reduction and freezing rate. It was also found that the blood protein hydrolysate remaining in broth also enhanced the survival rate. Among various protective substances, sucrose showed a high stabilizing effect with 10% (w/v) addition, by which the maximum survival rate (48.3%) and viable cell count (
CFU/g) were obtained.
Recovery of Poly(3-hydroxybutyrate) from the Coagulated Cells of Alcaligenes eutrophus.
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 206~212
The effects of the pretreatment with coagulants on the recovery efficiency of poly (3-hydroxybutyrate, PHB) synthesized in Alcaligenes eutrophus were investigated. Al-base or Fe-base coagulants, and the dispersion method of 30% hypochlorite solution and chloroform were used as coagulants and PHB recovery method, respectively The recovery efficiency of PHB from the cells harvested with Al-base coagulants at the range from 0 to 1000 mg-Al/L was similar to that from cells harvested without the coagulants. At these conditions, the concentrations of residual aluminium in the purified PHB were below 250 mg-Al/kg-PHB, indicating the effect of residual aluminum on the characteristics of the purified PHB can be insignificant. When the dosage of coagulants was over 1000 mg-Al/L, the PHB recovery remarkably decreased with increasing the coagulant dosage. However, the PHB recovery could be enhanced by the use of 50% hypochlorite solution instead of 30% hypochlorite solution. Even though the reduction of PHB recovery efficiency was not found by using Fe-base coagulants, the purified PHB was stained pale red due to residual iron, These results suggest that the use of Al-base coagulants did not exert bad influence on neither PHB recovery efficiency and PHB purity.
In-vitro Production of Glutathione Using Yeast ATP Regeneration System and Recombinant Synthetic Enzymes from Escherichia coli.
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 213~220
An ATP regeneration system was used for the production of glutathione which was synthesized by a sequential action of
-glutamyl-cysteine synthetase and glutathione synthetase. The synthetases above were produced in the recombinant E. coli (TG1/pDG7) with the highest specific production yield of 31 mg glutathione/g wet cell. Bakers yeast was considered to have economically a better ATP regeneration system although the glutathione production yield was lower than that of acetate kinase. It was also observed that the ATP regeneration system of bakers yeast was superior to that of Saccharomyces cerevisiae ATCC24858. The yield of glutathione production with bakers yeast was 36% with the ATP concentration of 5 mM. To avoid the cysteine limitation during the early phase of glutatione production, an extra cysteine was added at 2 hours after reaction and the production yield increased 1.91 times. The effectiveness of bakers yeast as an ATP regeneration system was proved by several sets of extra feeding experiments. The product inhibition by glutathione above 14 mM was also observed.
Changes of the Intestinal Microflora and Fecal Properties by Intake of Yoghurt Added Capsulated or Uncapsulated Bifidobacteria
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 221~225
Fourteen healthy volunteers ranged in ages from 20 to 30 were served to administrate two types of yoghurt (2 bottles/day) such as one added uncapsulated-Bifidobacteria (Y-UCB) and the other added capsulated-Bifdobacteria (Y-CB) for 4 weeks, and the changes of intestinal microflora and fecal properties were studied. After administration of Y-UCB, the viable cell counts of fecal Bifidobacteria (p<0.01) and Lactobacilli (p<0.05) were significantly increased, however, fecal pH, moisture content and tile viable cell counts of coliform bacteria in feces were not changed when they were compared to those before administration (control). After administration of Y-CB, the viable cell counts of Bifidobacteria were significantly increased (p<0.01) and viable cell counts of coliform bacteria were significantly decreased (p<0.05), however, fecal pH, moisture content, and viable cell counts of Lactobacilli were not changed when they were compared to those before administration. High level of fecal Bifidobacteria and low pH were maintained after 2 weeks from ceasing the administration of both types of yoghurt when they were compared to those before administration. In conclusion, there were not significant differences between two types, Y-CB and Y-UCB in the changes of fecal pH, moisture content, and the viable cell counts of Bifidobacteria, Lactobacilli, coliform bacteria after the administration.
Medium Optimization for Fibrinolytic Enzyme Production by Bacillus subtilis KCK-7 Isolated from Korean Traditional Chungkookjang.
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 226~231
The medium optimization was investigated to maximize the production of fibrinolytic enzyme by Bacillus subtilis KCK-7 isolated from Chungkookjang, which could hydrolyze the fibrin produced through the blood coagulation mechanism in human body. The simultaneous addition of 5% soluble starch and 0.5% cellobiose to the medium as carbon sources resulted in the highest production of the fibrinolytic enzyme. Likewise, the optimized composition of medium appeared to be 0.5% peptone, 0.3% beef extract, 0.5% cellobiose, 5% soluble starch, 2% raw soybean meal and 0.02% Na
. In addition, the fibrinolytic enzyme production by Bacillus subtilis KCK-7 reached to the maximum level after the cultivation for 48 hr, using the optimized medium.
-Mannosidase from Sporolactobacillus sp. M201.
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 232~237
A bacterial strain producing high levels of an extracellular
-mannanase and intracellular
-galactosidase was isolated from soil. The strain isolated was identified as a strain of Sporolactobacillus sp. and designated as Sporolactobacillus sp. M20l. Synthesis of
-mannanase by Sporolactobacillus sp. M20l was induced by sucrose, maltose, or locust bean gum. The highest induction rate was obtained with 2% locust bean gum added to the culture medium as a sole carbon source. On the other hand, induction of
-mannosidase was observed only with locust bean gum. The optimal media for the enzyme production were established as follows: for
-mannanase; 2% locust bean gum, 0.5% peptone, 0.2% KH
, 80 mg/l MgSO
, and 8 mg/l ZnSO
(pH 6.0), and for
-mannosidase; 2% locust bean gum, 0.5% yeast extract, 0.2% KH
, 80 mg/l MgSO
, and 8 mg/l ZnSO
(pH 5.0). The optimal culture temperatures for production of
-mannosidase were found to be 37
, respectively. Under the optimal culture conditions, the production of
-mannosidase reached the highest levels of 10.6 units/ml and 1.35 units/ml after 30 h and 24 h cultivation, respectively.
Enzyme-Linked Immunosorbent Assays of Pseudomonas tolaasii, a Bacterial Brown Blotch Pathogen of Oyster Mushroom.
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 238~243
For simple and rapid detection of Pseudomonas tolaasii (PT), a bacterial brown blotch pathogen of oyster mushroom, enzyme-linked immunosorbent assays (ELISA) were developed. To produce specific antibody, PT (
cfu) and Freund's adjuvant were subcutaneously immunized into rabbits several times. By using the antiserum showing the highest titer, we established noncompetitive and competitive ELISA's. Standard curves of the ELISA's showed that the detection limits were
cfu/ml, respectively When investigated by noncompetitive ELISA, cross reactivities of the anti-PT antibodies against P. agarici, P. reactans, and other fluorescent Pseudomonas spp. were very low (<1/10
), but those against P. solanacearum, Erwinia chrysanthemi, Streptococcus mutans, Xanthomonas citri, and a fungus Fusarium oxysporum were almost none. However, when investigated by competitive ELISA, the reactivities against any other strains except PT were almost none. When the ELISA's were applied to 18 strains derived from mushrooms in order to identify PT, only 11 strains showing both pathogenicity and white line reactivity were obviously positive. These results showed that the ELISA's could be convenient tools to detect PT in accordance with existing methods.
Optimization of Culture Conditions for Production of a High Viscosity Polysaccharide, Methylan, by Methylobacterium organophilum from Methanol.
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 244~249
An extracellular polysaccharide, methylan, was produced under the specific conditions by Methylobacterium organophilum from methanol. The specific growth rate of cells was approximately constant regardless of C/N ratio and the specific product yield was maximum at a C/N ratio of 30. Methylan production was suppressed by the deficiency of mineral ions such as Mn
ion. The optimal pH for cell growth and methylan production was 7. Whereas the optimal temperature for cell growth was found to be 37
, that for methylan production was 3
. The methanol concentration above 4% completely inhibited the cell growth. The initial methanol concentration for the maximal production of methylan was 0.5% (v/v) and above this concentration, methylan production was markedly inhibited. To overcome the substrate toxicity and inhibition for both cell growth and methylan production, a fed-bach culture of intermittent feeding within 5 g/l methanol was conducted under the optimal culture condition. Methylan production of was stimulated by nitrogen limitation and methylan was accumulated up to 8.7 g/1 and cell mass also increased up to 12.4 g/l.
Optimization of Culture Conditions for D-Tagatose Production from D-Galactose by Enterobacter agglomerans.
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 250~256
D-Tagatose production from D-galactose was investigated using 35 type strains of American Culture Type Collection (ATCC) and Korean Collection for Type Cultures (KCTC) which have potential to produce D-tagatose. Enterobacter agglomerans ATCC 27987 was selected as a D-tagatose producing strain due to its short fermentation time and high production of D-tagatose. Optimization of the culture conditions for D-tagatose production by E. agglomerans ATCC 27987 was performed. Among various carbon sources, D-galactose was the most effective carbon source for D-tagatose production. As the D-galactose concentration was increased, cell growth and D-tagatose production increased. Effect of nitrogen sources on D-tagatose production was studied. Of inorganic nitrogen sources, ammonium sulfate was effective one for D-tagatose production and yeast extract was the most suitable organic nitrogen nutrient. The concentrations of inorganic compounds such as KH
, and MgSO
O were also optimized for D-tagatose production. The optimal medium was determined to contain D-galactose of 20 g/l, yeast extract of 5.0 g/l, (NH
of 2.0 g/l, KH
of 5.0 g/l, K
HPO of 5.0 g/l, and MgSO
O of 5 mg/l. The optimal environmental conditions in a 250-
flask were found to be pH of 6.0, temperature of 30
, and agitation speed of 150 rpm. D-tagatose of 0.41 g/l could be obtained in 24 h from 20 g/l D-galactose at the optimal culture condition without induction and cell concentration.
Effect of re-based Coagulants on Cell Separation Efficiency from the Culture Broth of Alcaligenes eutrophus.
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 257~263
Alcaligenes eutrophus was successfully recovered from high cell density broth by pre-treatment with Fe-based coagulants. An inorganic coagulant, Fe
, and a polymerized coagulant, Ferix-3, were used. Good coagulation was observed in broad pH range of 3 to 13, the floe size was increased with increasing pH of culture broth. The optimum pH of fermentation broth for cell recovery was 10 to 13. The optimum coagulant dosages to recover cells with 95% cell recovery were increased with increasing cell concentration. Optimal coagulant dosage was lower when the polymerized coagulant was used rather than the inorganic coagulant. The coexistence of NH
+/ was increased coagulant requirement, and the coagulant requirement was 0.066g Fe
Modification of Pullulan Using Dextransucrase and Characterization of the Modified Pullulan.
;;;;;;John F. Robyt;
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 264~268
Many enzymes catalyze a primary reaction and/or secondary reaction. Dextransucrase usually synthesizes dextran from sucrose as a primary reaction. The secondary reaction of dextransucrase is the transfer of glucose from sucrose to carbohydrate accepters. We have reacted dextransucrase from Leuconostoc mesenteroides B-742CB with sucrose and pullulan as an acceptor under different reaction conditions; various concentrations of pullulan, enzyme, sucrose and different pHs and temperatures of reaction digests. The yield of modified pullulan was 57%(<
5%) of theoretical under the reaction condition of pH 5.2, temperature 28
, 0.37% of pullulan, and 0.l U/
of dextransucrase. Modified products were more resistant against the hydrolysis of pullulanase and endo-dextranase than those of native pullulan. The positions of glucose substitution in the modified products were determined by methylation followed by acid hydrolysis and analyzed by TLC. The products were modified by the addition of glucose to the position of C3, C4, C6 free hydroxyl group of glucose residues in the pullulan.
Decolorizing Characteristics of Crystal Violet by Enterobacter cloace MG82.
Microbiology and Biotechnology Letters, volume 26, issue 3, 1998, Pages 269~274
Decolorizing characteristics of crystal violet by Enterobacter cloace MG82, which can decolorize rapidly triphenylmethane dyes, were investigated. The higher growth and decolorization activity was shown at big ratio of dissolved oxygen in the medium. The decolorization activity of crystal violet revealed highest at the middle of lag phase. As the concentration of crystal violet was higher, the growth of E. cloacae MG82 and decolorizing activity of crystal violet by this strain were worse. The maximum concentration of crystal violet at which E. cloacae MG82 be able to grow was 375
M. E. cloacae MG82 was not able to use the crystal violet itself as a sole carbon source. So, it was shown that growth of E. cloacae MG82 and decolorization activity of crystal violet by this strain needed addition of another energy sources except this dye.