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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
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Volume & Issues
Volume 14, Issue 6 - Dec 1986
Volume 14, Issue 5 - Oct 1986
Volume 14, Issue 4 - Aug 1986
Volume 14, Issue 3 - Jun 1986
Volume 14, Issue 2 - Apr 1986
Volume 14, Issue 1 - 00 1986
Selecting the target year
Effect of Reactor Operation Mode on Citric Acid Production Using Immobilized Yeast
Lim, Dong-Joon ; Choi, Cha-Yong ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 1~1
Immobilized yeast cell (Candida lipolytica MX 9-11 R 3) was prepared by entrapping the whole cell in calcium alginate matrix. The fermentative production of citric acid from glucose was studied using this immobilized yeast cell in fluidized-bed reactor and packed-bed reactor. The productivity of citric acid was remarkably influenced by reactor operation mode. To find the merit of the fed-batch mode of operation, certain quantities of the reaction solution were removed from the reactor at regular time intervals with simultaneous make-ups with the fresh substrate solution of equal amounts in an attempt to keep the substrate concentration rather constant and 28% increase in productivity was noticed as compared with the case of pure batch mode operation. The pronounced effect of pH control in the repeated fed-batch reactor operations was evidenced by the 140 % higher productivity in the case of the pH-controlled reactor as compared with the one without pH control. The productivity of the citric acid was increased by the increased flow rate in both continuous fluidized-bed and packed-bed reactors. Citric acid production rate per bead for immobilized Candida lipolytica in the continuous fluidized-bed reactor was much higher than in the packed-bed reactor.
Studies on the Inhibitors on Aflatoxin Production by Aspergillus parasiticus R-716 - Isolation of Aflatoxigenic Fungi and Effects of Initial pH & Zn -
Chung, Duck-Hwa ; Kim, Chan-Jo ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 9~9
As a part of study on prevention of contamination of food and agricultural products with aflatoxin, and aflatoxigenic strain was isolated from natural sources of microorganisms and effects of initial pH,Zn on aflatoxin production by the isolated. The cunclusion of this study were as follows. From 367 natural sources of microorganisms, 837 strains were isolated. Out of them, 16 strains (1.9%) had fruorescent substance, which was presumed aflatoxin-like substance by thin layer chromatography and 5 strains of them (strain number R-96, S-127, P-507, R-716 and B-821) were found to produce relatively larger amount of aflatoxin than any others by high pressure liquid chromatography. Especially, isolated strain No. R-716 produced 1649.02
/30g of total aflatoxin on rice medium, and was selected. The results obtained in light of the manual of Rafer had been shown that the selected strain was estimated as Aspergillus parasiticus group, and was named Aspergillus parasiticus R-716. Aflatoxin production of this strain in modified SLS medium was the highest at initial pH 5.0 but fungal growth at pH 5.5.It was appeared that the absence of Zn almost blocks fungal growth and aflatoxin production, but Zn level of 10mg/liter was adequate for optimum aflatoxin production in SLS medium.
Protoplast Fusion between Saccharomyces cerevisiae and Candida lipolytica - Conditions for Protoplast Fusion -
Bae, Young-Seuk ; Seu Jung-Hwn ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 17~17
Two different auxotrphic protoplasts of Saccharomyces cerevisiae and Candida lipolytica were fused with the aid of polyethylene glycol (PEG) and calcium ions. These auxotrophic strains were induced by treatment of N-methyl-N'-nitro-N-nitrosoguanidine (NTG), and they were used for protoplast fusion. The fusion efficiency was much higher by incubating protoplasts in PEG(MW 4,000) solution (pH 8.0) for 10 min and by using potassium chioride for osmotic stabilizer. The intergeneric fusion frequency was
,equivalent to one-tenth of intraspecific fusion frequency.
Protoplast Fusion between Saccharomyces cerevisiae and Candida lipolytica - Properties of Fusant -
Bae, Young-Seuk ; Seu Jung-Hwn ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 23~23
Properties of the fusants between Saccharomyces cerevisiae and Candida lipolytica were studied. Fusants assimilated carbon sources such as saccharose, raffinose, erythritol and citric acid. Morphological properties of the fusants were different from those of the parent cells. The fusants were larger in size, and they formed an elongated and budding cells. Two fusioned strains, FSCL 1-9 and FSCL 2-4, produced alcohol and citrate simultaneously ; the alcohol productions by the fusants were 2.4 % and 0.7 compare with 3.3 % of S. cerevisiae, the citrate productions were 28.5 mg/ml and 34 mg/ml compare with 64 mg/ml of C. lipolytica.
Saccharification of Uncooked Starches in an Attrition-Coupled Reaction System
Lee, Yong-Hyun ; Jo, Ku-Hyung ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 29~29
The saccharification of uncooked starch was carried out in an attrition-coupled reaction system. The mechanical movement of the milling-attrition media contained in the starch slurry enhanced the hydrolytic action of the starch liquifying and saccharifying enzymes significantly. The enhancement may be due to the attrition effect rather than the milling effect. It was found that the enzymes were relatively stable even under the attrition state. In the case of the naked barley powder, both saccharification rate and sugar yield were improved compare with conventional cooking saccharification method. The effectiveness of the various milling media, such as, glass bead, polyacetal bead, and teflon bead were evaluated. Even at the concentration as high as 38 % (w/v). the starch can be effectively hydrolyzed in an attrition coupled reaction system. Although further studies need to be conducted to evaluate the feasibility of its commercialization, this novel system provides an improved method for the saccharification of starch without cooking.
Properties of Intracellular Aminopeptidase and Its Interactions with Acide Proteases in Rhodotorula glutinis
Lee, Tae-Ho ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 37~37
In addition to two kinds of proteases in Rhodotorula glutinis K-24, an aminopeptidase activity was detected, but carboxypeptidase was not. The aminopeptidase was purified about 480-fold from homogenate of Rh. glutinis by pH treatment, DEAE-Sephadex A-50,gel filtration on Sephadex G-200, Hydroxyapatite and DEAE-Sephadex A-50 column chromatography. The final preparation was electrophoretically homogenous. The molecular weight was 62,000. The optimum pH was 6.0 and the optimum temperature was
This enzyme was inhibited by PCMB, but not by O-pen-anthroline and EDTA. The aminopeptidase could hydrolyze peptides with leucine in amino terminal end, but it showed the low hydrolytic activities toward other peptides. As these results, this enzyme was considered a leucine aminopeptidase. This enzyme was inactivated only by the acid protease II localized in the particle fraction of cells, but not by the acid protease I.
The Changes of Mycelial Composition according to Differentiation of Rhizopus oryzae
Youn, Hee-Ju ; Choi, Young-Keel ; Cho, Key-Seung ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 45~45
Different growth form was obtained by treatment of surfactants into culture media during submerged culture of Rhizopus oryzae.Small pelletal form was induced by treatment of 0.18 mM of sodium dodecyl sulfate and pulpy form by 0.48 mM of sodium deoxycholate, while filamentous form was induced without supplement of surfactant. Change of macromolecule contents, such as protein, nucleic acid, and lipid in different growth form, was examined throughout cultural periods. Productivity and content of protein and nucleic acid are higher in filamentous form than those in pelletal form, but trend of lipid is contrary to that of protein and nucleic acid. Content of phospholipid and sterol was also analysed. Molar ratio of free-sterol per phospholipid in pelletal growth form was measured as the lowest throughout cultural period, which means that physiology of pelletal growth is far different from that of filamentous growth form.
Regulation of Cephalosporin C Acetyl-hydrolase in Cephalosporin C Fermentation by Cephalosporium acremonium M-113
Choi, Sang-Ho ; Lee, Jeong-Kuk ; Kho, Young-Hee ; Min Tae-Ick ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 51~51
In the fermentation of cephalosporin C (CPC) using a mutant strain, Cephalosporium acremonium M-113, CPC was converted into deacetyl cephalosporin C (DCPC) by cephalosporin C acetyl hydrolase (CAH). After complete consumption of glucose in fermentation broth, the CAH activity appeared as CPC started to accumulate and then increased rapidly. The CAH activity was regulated by glucose concentration and the regulatory mechanism was not by inhibition but by repression. During the CPC fermentation, continuous feeding of glucose at low level into fermentation broth could regulate the CAH activity as well as increase the production of CPC by suppressing the conversion of CPC into DCPC.
Effect of Olive Oil on the Stability of Lipases in Organic Solvents
Gwon, Dae-Yeong ; Lee, Jun-Sik ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 57~57
The Protective effects of olive oil on the lipase stability against the denaturation or deactivation of protein in organic solvents were investigated for the study of enzymatic fat splitting of interesterification. The enzymes used were the lipases from Candida rugosa and Rhizopus arrhizus for fat splitting and interesterification, respectively. When lipases were incubated in organic solvents with olive oil, the substrate, the lipase from C. rugosa in isooctane and the lipases from R. arrhizus in isooctane and diisopropylether were substantially stabilized. The lipase stability increased in proportion with the concentration of olive oil in organic solvents.
Volatiile Flavor Compounds Produced by the Yeast Hansenula anomala
Shin, Hyun-Kyung ; Ahn, Byung-Hak ; Kang, Hoon-Seung ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 63~63
Hansenula anomala was cultured with varying the media composition and incubation time to examine their effect on the production of interesting aroma compounds. Glucose and phenylalanine were found to be the best carbon and nitrogen sources used, respectively, in terms of the nature and intensity of the aroma produced. The time course study with headspace vapor showed that alcohols had been formed at first and then converted to the corresponding aceate esters. In the aroma concentrate of the culture broth, 14 volatile compounds were identified tentatively or positiviely by comparison of gas chromatographic retention times and mass spectra with those of authentic compounds. The fruity-floral note of the headspace vapor and aroma concentrate is probably due to the major compounds such as ethyl acetate, isobutyl acetate, isoamyl acetate, phenethyl acetate and phenethyl alcohol.
Partial Purification and Catalytic Properties of Alchol Acetyltransferase from Hansenula anomala
Kang, Hoon-Seung ; Kim, Jung-Hoe ; Shin, Hyun-Kyung ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 69~69
Alcohol acetyltransferase responsible for the formation of isobutyl acetate from isobutyl alcohol and acetyl-CoA was extracted from Hansenula anomala and purified about 50-fold by ammonium sulfate fractionation, gel filtration on Sephadex G-150 and ion exchange chromatography on DEAE-Sephadex A-50. The enzyme was most active at
and pH 7. Alcohol acetyltransferase was strongly inhibited by heavy metal ions or unsaturated fatty acids with higher degree of unsaturation. The
values of the enzyme for the formation of acetic esters from the corresponding alcohols were 1.51 and 0.77 for isobutyl alcohol, 0.72 and 0.45 for isoamyl alcohol, respectively.
Studies on Production of
-galactosidase by a mutant of Lactobacillus sporogenes
Yu Wha-Chun ; Lee, Jung-Chi ; Choi, Yong-Gin ; Yang, Han-Chul ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 75~75
Cells of Lactobacillus sporogenes were treated with N-methyl-N'-nitro-N-nitrosoguanidine and by the treatment a mutant strain, L. sporogenes G-76, capable of producing highly enhanced levels of extracellular
-galactosidase was obtained. The enzyme activity in L. sporogenes G-76 was increased about 40.9% compared to that in the parent strain. A series of experiment proved that L. sporogenes G-6 was not a constitutive mutant for
-galactosidase. It also was found that the mutant had a normal catabolite repression system. Optimum pH and optimum temperature of
-galactosidase of L. sporogenes G-76 were nearly the same as those of the parent strain. There was also no great difference in affinity constants of the two enzymes of different origins. But the inhibitor constant of
-galactosidase from the mutant for lactose in the ONPG hydrolysis was revealed to be about 4-fold higher than that of the enzyme from the parent strain. Moreover, the value for glucose in the mutant was approximately 11 times higher than that in the parent. There were also significant differences between the two enzymes of different sources in their activation by metal ions. especially by ferrous and manganese ion. The data obtained in the experiments on the enzyme properties strongly suggest that the altered binding characteristics of the
-galactosidase of L. sporogenes G-76 was due to a mutation in the structural gene for the enzyme, and this was also responsible for the increase in
-galactosidase activity in L. sporogenes G-76.
Breeding of Azospirillum spp. for effective association with paddy rice 1. Selecton and characterization of nitrate reductase negative mutants
Kang, Kyu-Young ; Choi, Do-Yeol ; Yun, Han-Dae ; Cho, Moo-Je ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 85~85
Nitrogen-fixing (acetylene-reduction) activity associated with roots of 12 different rice varieties was assayed at heading stage by an in situ chamber acetylene reduction method. The in situ acetylene reducton activity and population of
-fixing bacteria obtained on nitrogen-free malate medium for Azospirillum spp. enrichment showed postive correlation. Azospirillum spp. with high nitrogenase activity were isolated from the rice roots. Eleven nitrate reductase negative
mutants were selected from chlorate resistant mutants. All mutants retained their nitrogenase activity, though lower than that of parent isolates except SK16CR2, and were nitrate reductase negative and nitrite reductase postive. Nitrogenase activity of
mutant SK16CR2 has not been suppressed by 10 mM
whereas that of wild type has. This mutant assimilated nitrite but not nitrate as sole nitrogen source for growth. Three different but related evidences, obtained from suppression of nitrogenase activity of
mutant by coinoculatin of
mulant and wild type
isolates in nitrate medium, reinitiation of nitrogenase activity from wild type isolates under prolonged (4-5 day) incubation in nitrate medium at which nitrite content in the medium dissipated, and inhibition of preformed nitrogenase by nitrite but not nitrate, strongly indicated that nitrite formed from nitrate in the medium by nitrate reductase was the actual inhibitor of nitrogenase from Azospirillum spp.
Studies on the Development of the Bacillus thuringiensis pesticide 1. Purification of B. thuringiensis subspp. endotoxin crystals
Lee, Hyung-Hoan ; Kang, Tae-Sook ; Oh, Chang-Keun ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 91~91
B. thuringiensis 6 subspp. were cultured in GBY medium and then their endotoxin crystals were purified with NaBr or Renografin-76 gradient centrifugation. The crystals were banded between 60 to 65% concentrations of Renografin and between 55 to 60% concentrations of NaBr gradients. The Renografin densities in which the crystals of each strain were banded were 1.281 g/
for Bt var. kurstaki, 1.2771 for Bt var. thuringiensis, 1.2756 for Bt var. sotto, 1.271 for Bt var. Pakistani, 1.2739 for Bt var. tolworthi and 1.2821 for Bt var.israelensis. The NaBr densities were 1.3194 for Bt var. kurstaki, 1.3158 for Br var. thuringiensis, 1.3141 for Bt var. sotto, 1.3211 for Bt var. pakistani, 1.3123 for Bt var. tolwarthi and 1.311 for Bt var. israelensis. The ratios of the wet weights of the crystals to the total cell weights ranged from 25.74% to 28.83% by Renografin purification, and from 21.99% to 25.14% by NaBr. The shapes of Bt var. sotto, var thuringiensis and var. tolworthi were bipyramidal. but Bt var. Pakistani appeared to be rod or bipyramidal.
Studies on the Development of the Bacillus thuringiensis pesticide 2. Electrophoretic analysis of B. thuringiensis subspp. endotoxin
Lee Hyeong-Hoan ; Kang, Tae-Sook ; Seo, Jung-Hee ;
Microbiology and Biotechnology Letters, volume 14, issue 1, 1986, Pages 97~97
Alkali-solubilized endotoxin proteins of B. thuringiensis subsp. were purified by Sepharose gel filtration and then aliquotes of the fractions showing peaks were dialyzed and electrophoresed on SDS-polyacrylamide gel. Each subspecies showed two protein bands on the gel. The subunit protein molecular weights of Bt. var. kurstaki were approximately 138,000 and 69,000 daltons, those of Bt var. thuringiensis 132,000 and 70,000, Bt var. sotto 133,000 and 71,000, Bt. var. pakistani 134,000 and 72,000, Bt. var. israelensis 128,000 and 71,000 and Bt. var. tolworthi 135,000 and 69,000.