• Applied Chemistry for Engineering
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• v.30 no.6
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• pp.681-686
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• 2019

In this work, the effect of the culture medium composition on microbial growth and ethanol production in Clostridium autoethanogenum culture was investigated to enhance the ethanol productivity. D-Ca-pantothenate, vitamin B₁₂ (as vitamins), and sodium sulfide (as sulfur source) were selected as examined components, and the effects of components' concentration on cell growth and ethanol production was investigated. For D-Ca-pantothenate concentrations varing from 0.5, 5, 50 and 500 mg/L, a slight increase in the ethanol production was observed at the 0.5 mg/L, but negligible differences in microbial growth and ethanol production were measured for the concentration ranges examined. The effect of vitamin B₁₂ concentrations from 0.1, 1.0, 10, and 100 mg/L on the microbial growth and ethanol production was investigated, and it was found that the ethanol production using a 0.1 mg/L of vitamin B₁₂ concentration increased by 245% compared to that of using the basic medium concentration (10 mg/L). The effect of sodium sulfide concentrations (0.5, 5, and 10 g/L) on the microbial growth and ethanol production was also studied, and the inhibition of microbial growth was observed when the sodium sulfide usage was over 0.5 g/L. In conclusion, changes in D-Ca-pantothenate and sodium sulfide concentrations did not affect the ethanol production, whereas even a 100 times lower concentration of vitamin B₁₂ than that of the basic medium improved the production.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.668-673
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• 2013

A recombinant E. coli co-expressing ALA synthase (hemA), NADP-dependent malic enzyme (maeB), and dicarboxylic acid transporter (dctA) was reported to synthesize porphyrin derivatives including iron-containing heme. To enhance the synthesis of bacterial heme, five genes of the porphyrin biosynthetic pathway [pantothenate kinase (coaA), ALA dehydratase (hemB), 1-hydroxymethylbilane synthase (hemC), uroporphyrinogen III synthase (hemD), and uroporphyrinogen III decarboxylase (hemE)] were amplified in the recombinant E. coli co-expressing hemA-maeB-dctA. Pantothenate kinase expression enabled the recombinant E. coli to accumulate intracellular CoA. Intracellular ALA was the most enhanced by uroporphyrinogen III synthase expression, porphobilinogen was the most enhanced by ALA dehydratase expression, uroporphyrin and coproporphyrin were the most enhanced by 1-hydroxymethylbilane synthase expression. The strain co-expressing coaA, hemA, maeB, and dctA produced heme of $0.49{\mu}mol/g$-DCW, which was twice as much from the strain without coaA expression. Further pathway gene amplifications for the porphyrin derivatives are discussed based on the results.

• Microbiology and Biotechnology Letters
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• v.1 no.2
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• pp.75-78
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• 1973

Effects of nitrogen sources, supplement of vitamins and minerals on the accumulation of 5'-inosinic acid by an adenineless mutant of Brevibacterium ammoniagenes were examined. Maximal yield of 5'-inosinic acid was attained by the use of yeast extract. as organic nitrogen source Casamino acid supplemented with $Mn^{＋＋}$, $Zn^{＋＋}$ Ca-D-pantothenate and thiamine HCl could be subsitute for it. Subsequent experiment using the defined medium showed that the concentration of these trace element in the medium affected inosinic acid accumulation markedly. And it was found that the simulataneous addition of $Mn^{＋＋}$ (20$\mu\textrm{g}$1). $Zn^{＋＋}$(10$\mu\textrm{g}$1). thiamine Hcl(10mg/1) and Ca-D-pantothenate (5mg/l) to the defined medium stimulated inosinic acid accumulation, from which 7mg/ml of inosinic acid was obtained.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1689-1695
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• 2010

Pantothenate kinase (PanK) catalyzes the first step in the biosynthesis of the essential and ubiquitous cofactor coenzyme A (CoA) in all organisms. Here, we report the identification, cloning, and characterization of panK-sp from Streptomyces peucetius ATCC 27952. The gene encoded a protein of 332 amino acids with a calculated molecular mass of 36.8 kDa and high homology with PanK from S. avermitilis and S. coelicolor A3(2). To elucidate the putative function of PanK-sp, it was cloned into pET32a(+) to construct pPKSP32, and the PanK-sp was then expressed in E. coli BL21(DE3) as a His-tag fusion protein and purified by immobilized metal affinity chromatography. The enzyme assay of PanK-sp was carried out as a coupling assay. The gradual decrease in NADH concentration with time clearly indicated the phosphorylating activity of PanK-sp. Furthermore, the ca. 1.4-fold increase of DXR and the ca. 1.5-fold increase of actinorhodin by in vivo overexpression of panK-sp, constructed in pIBR25 under the control of a strong $ermE^*$ promoter, established its positive role in secondary metabolite production from S. peucetius and S. coelicolor, respectively.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.880-886
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• 2015

Bacterial heme was produced from a genetic-engineered Escherichia coli via the porphyrin pathway and it was useful as an iron resource for animal feed. The amount of the E. coli-synthesized heme, however, was only few milligrams in a culture broth and it was not enough for industrial applications. To analyze heme biosynthetic pathways, an engineered E. coli artificially overexpressing ALA synthase (hemA from Rhodobacter sphaeroides) and pantothenate kinase (coaA gene from self geneome) was constructed as a bacterial heme-producing strain, and both the transcription levels of pathway genes and the intermediates concentrations were determined from batch and continuous cultures. Transcription levels of the pathway genes were not significantly changed among the tested conditions. Intracellular intermediate concentrations indicated that aminolevulinic acid (ALA) and coenzyme A (CoA) were enhanced by the hemA-coaA co-expression. Intracellular coproporphyrinogen I and protoporphyrin IX accumulation suggested that the bottleneck steps in the heme biosynthetic pathway could be the spontaneous conversion of HMB to coproporphyrinogen I and the limited conversion of protoporphyrin IX to heme, respectively. A strategy to increase the conversion of ALA to heme is discussed based on the results.

• Applied Biological Chemistry
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• v.15 no.1
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• pp.59-63
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• 1972

These experiment were conducted to study the effects of various vitamins and amino acids upon the growth of Saccharomyces rouxii T9 and the results obtained were as follows. (1) As a growth factor, inositol, ribofavin, niacin and para amino benzoic acid were not required. (2) Though biotin, thiamin and Ca-pantothenate were adaptably required, vitamins required in absolute were not existed. (3) The growth rate of Saccharomyces rouxii T9 in the deficient group of biotin, thiamin, pyridoxine, riboflavin and Ca-pantothenate were more decreased on the media containing 26% of NaCl than containing none of NaCl in the earlystage of cultivation, while the growth rate showed the opposition tendency in the latter term of cultivation. (4) As an amino acid, methionine, tryptophan, serine, threonine, cystine, glycine, leucine and valine showed systematically the effects of addition in the compound media containing $(NH_4)_2SO_4$ as a nitrogen sources. (5) The growth rate of Saccharomyces rouxii T9 in the addition group of histidine, lycine, arginine, aspartic acid, proline and tyrosine were somewhat decreased on the media containing higher concentration of NaCl comparison with none NaCl media in the early stage of cultivation, showing the similar or increasing tendency in the latter term of cultivation.

• Microbiology and Biotechnology Letters
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• v.8 no.1
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• pp.9-18
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• 1980

During an extensive screening tests of yeasts for their RNA formation, it was found that Cryptococcus laurentii had especially high RNA content and high dry cell weight, when hydrolyzate of sliced and dried sweet potatoes was used as a carbon source. Growth conditions of this strain were examined, and the most desirable results were obtained at 48 hours of cultivation on a reciprocal shaker at 3$0^{\circ}C$ with initial pH 6.0. Under the above conditions, the RNA content and yield of dry cells were investigated using various media compositions. Ammonium sulfate 0.40%, peptone 0.6 ％, and yeast extract 0.4% were appeared to be favorable as a nitrogen sources. The optimum concentrations of K $H_2$P $O_4$, M $n^{++}$, C $O^{++}$ were 0.05 ％, 0.1 ％, and 0.001 ％, respectively. Ca-pantothenate, 400$\mu\textrm{g}$/$m\ell$, showed relatively favorable effects as a growth factor. The maximum RNA content obtained in this study was 16.8 ％ of the total dry cell weight.t.t.

• Applied Biological Chemistry
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• v.39 no.1
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• pp.16-19
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• 1996

The yeast strains isolated for Choungju brewing in the previous report were examined for their microbiological characteristics, together with some comparative tests with Japanese sake yeasts. The isolates KP-16, 21 and 54 were identified as the strains belong to Saccharomyces cerevisae according to the morphological and physiological properties described in Lodder's 'The Yeasts - A texanomic study'. The isolates were grouped into the pink-colored strains by 2,3,5-tripheny tetrazolium chloride over-lay method. The strains KP-16 and 21 were found to be distinguished from the strain KP-54 in aspects of fermentation of sugars, assimilation of carbon sources, and pellicle formation on malt extract broth. ${\alpha}-methyl-D-glucoside$ was not assimilated or fermented by the isolated yeast strains and this is one of the different characters from the Japanese sake yeasts. The isolated strains appeared to have the requirements for biotin and pantothenate, and to have higher tolerance to ethanol than the Japanese sake yeasts. The biotin requirement was not found in the sake yeasts.

• Microbiology and Biotechnology Letters
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• v.9 no.3
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• pp.145-152
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• 1981

Microorganisms from the waste water of starch industry, were isolated and a strain, Y-124, possessing a powerful enzymic activity was selected and identified as a member of the genus Bacillus. The ideal cultural condition for the formation of $\alpha$-amylase form Bacillus Y-124 and its preservation was investigated in connection with the biotechnological and industrial approach to the bulk enzyme production. High yield of $\alpha$-amylase was observed in medium containing casein as well as calcium pantothenate in this work. Calcium ions were found to have an effect in forming this particular enzyme. Ammonium phosphate dibasic was an important inorganic nitrogen source for the formation of $\alpha$-amylase. And preservation of this enzyme was greatly affected by calcium or sodium salts. The addition of calcium carbonate or sodium sulfate presented the most effective result for the prevention of its denaturation to various factors. The above data was obtained with crude enzyme preparation.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.143-148
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• 1997

The optimum concentrations of pH, sucrose and vitamins for the growth and tropane alkaloid production of hairy root clone DTLA9 (best growth line) were investigated. The optimum pH in growth and tropane alkaliod production of DTLA9 clone in SH (Schenk and Hildebrandt, 1972) basal medium without growth regulator were pH 6.3 and 6.5, respectively. Also, the optimum sucrose concentration in growth and tropane alkaliod production in the same medium were 3.0 and 2.8%, respectively. The optimum concentrations of ascorbic acid, D-pantothenate, nicotinic acid, pyridoxine, riboflavin, and thiamine on the growth of DTLA9 clone in SH basal medium without vitamins were 0.1 mM, 0.003 mM, 0.07 mM, 0.002 mM, 0.025 mM, and 0.01 mM, respectively. In particular, supplement of 0.1 mM ascorbic acid to SH basal medium without vitamins stimulated the tropane alkaloid production.