• KSBB Journal
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• v.18 no.3
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• pp.197-201
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• 2003

Automatic addition of glucose, ammonium and phosphate to alcohol distillery wastewater and their control at low concentrations have been carried increase the cell concentration of a baker's yeast cultivated in the wastewater. Glucose was automatically added using dissolved oxygen as the control parameter, and maintained below 300 mg/L. Ammonium was automatically added by a pH-stat method and maintained in the low range of 12.6~17.4 mM. An automated FIA system, which used an ascorbic acid-based method was developed for the automatic analysis nad addition of phosphate. With this system, the phosphate concentration was succesfully analysed and controlled afrer 19.4 hr in the range 23.3~43.4 mg/L. The cell concentration was increased by 33.0-fold by the addition of these three nutrients. The overall specific growth rate of the yeast was 0.19 $hr^{-1}$.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1867-1876
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• 2017

Most of the biosynthetic pathways for secondary metabolites are influenced by carbon metabolism and supply of cytosolic NADPH. We engineered carbon distribution to the pentose phosphate pathway (PPP) and redesigned the host to produce high levels of NADPH and primary intermediates from the PPP. The main enzymes producing NADPH in the PPP, glucose 6-phosphate dehydrogenase (encoded by zwf1 and zwf2) and 6-phosphogluconate dehydrogenase (encoded by zwf3), were overexpressed with opc encoding a positive allosteric effector essential for Zwf activity in various combinations in Streptomyces lividans TK24. Most S. lividans transformants showed better cell growth and higher concentration of cytosolic NADPH than those of the control, and S. lividans TK24/pWHM3-Z23O2 containing zwf2+zwf3+opc2 showed the highest NADPH concentration but poor sporulation in R2YE medium. S. lividans TK24/pWHM3-Z23O2 in minimal medium showed the maximum growth (6.2 mg/ml) at day 4. Thereafter, a gradual decrease of biomass and a sharp increase of cytosolic NADPH and sedoheptulose 7-phosphate between days 2 and 4 and between days 1 and 3, respectively, were observed. Moreover, S. lividans TK24/pWHM3-Z23O2 produced 0.9 times less actinorhodin but 1.8 times more undecylprodigiosin than the control. These results suggested that the increased NADPH concentration and various intermediates from the PPP specifically triggered undecylprodigiosin biosynthesis that required many precursors and NADPH-dependent reduction reaction. This study is the first report on bespoke metabolic engineering of PPP routes especially suitable for producing secondary metabolites that need diverse primary precursors and NADPH, which is useful information for metabolic engineering in Streptomyces.

• Journal of Microbiology and Biotechnology
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• v.7 no.2
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• pp.127-131
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• 1997

Alkaline phosphatase (APase) was found to be inducible in Anabaena sp. strain CA Growth was less than control in presence of most amino acids except glycine and serine, but most amino acids enhanced APase activity. Highest APase activity was recorded in tyrosine supplemented culture followed by hydroxyproline, cystein, valine and glutamic acid. Threonine supplemented material showed lowest APase level (1.8 nmol/mg protein/min). Lactose, glucose, sodium pyruvate and succinate stimulated growth but not APase activity. APase activity was high in the presence of sucrose, mellibiose, mannitol, arabinose, maltose and sorbose, even though the growth in these supplements was less than in control. Organic phosphate sources supported good growth of the organism. Best growth occurred in presence of inorganic phosphate, adenosine diphosphate, fructose 1,6-diphosphate or ribulose 1,5-diphosphate, followed by other phosphorus sources tested. APase activity in presence of any of the organic phosphate sources was 3 to 5 fold low as compared to phosphate limited culture. Also, there was no APase activity in cultures grown on inorganic phosphate. These data indicate that most amino acids and a few carbohydrates (sucrose, mellibiose, arabinose and sorbose) are suitable for APase production. Lactose, glucose, pyruvate or succinate may be used as a carbon source during photoheterotrophic growth of the cyanobacterium. Glycine and serine are preferred nitrogen sources for its growth. Phosphate repressible APase activity has been found in Anabaena sp. strain CA.

• KSBB Journal
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• v.8 no.4
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• pp.375-381
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• 1993

The microorganisms producing a lipoxygenase inhibitor were screened from a wide variety of sources. The isolated strain was assigned to genus Penicillium by its cultural and morphological characteristics. The proper medium for the production of lipoxygenase inhibitor was composed of glucose 3.0%, ammonium sulfate 0.4%, and potassium phosphate (dibasic) 0.1%. The cultivation for lipoxygenase inhibitor production was carried out in 500m1 Erlenmyer flasks containing 100m1 of the medium at $30^{\circ}C$ by cultivating reciprocally. The highest lipoxygenase inhibitor production was observed after 8 days of cultivation. The inhibitor was the low molecular weight substance and inhibited specifically soybean origin lipoxygenase.

• Korean Journal of Microbiology
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• v.29 no.5
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• pp.329-338
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• 1991

From July 1985 to December 1986, 28 variables of phycal-chemical factors, bacteria and heterotrophic activity were investigated 17 times at 3 stations in the estuary of Naktong River and the influences of environmental factors to bacterial population and heterotrophic activity were analyzed through multiple regression. The results of multiple regression were as follows. At station 1, total bacteria and heterotrophic bacteria(Z-25) could explain 57% of the variation of maximum uptake velocity for glucose and 54% of turnover time for glucose was explained by total coliform bacteria and MBOD, Sixty four percent of the variation of Kt+SN was accounted for salinity, MBOD-N and inorganic phosphate. Turnover rate for acetate was also accounted for the change of MBOD-P by 56%. At station 2 maximum uptake velocity for glucose depends on MBOD-N by 81%; turnover time on bacteria by 50%; Kt+Sn on avilable nutrient by 61%. More than 50% of maximum uptake velocity and turnover time for glucose were influenced by bacteria and that of Kt+Sn by the change of nutrient in the surface water of station 3. In the bottom water of station 3, the change of maximumuptake velocity, turnover time and Kt+Sn for glucose was controlled by total bacteria and available nutrient, bacteria, the change of nutrient salts respectively. On the whole, more than 50% of maximum uptake velocity and turnover time for glucose could be due to the change in the number of bacetria and the value of Kt+Sn was affected by the change of nutrient salts. Turnover rate for acetate was controlled by available phosphate at station 1 and by bacteria at station 2 and 3, which showed a distinct difference between the environmental factors which govern the rate of glucose and acetate uptake in the Naktong esturine ecosystem. And bacterial communities were controlled by available nutrients at station 1, by nutrient salts and salinity at station 2 and in the surface water of station 3 and by salinity in the bottom water of station 3.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.686-692
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• 2016

This study was done to investigate the antidiabetic effect of ethanol extract from Platycodon grandiflorum root in Streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by intravenous injection of STZ at a dose 45mg/kg.b.w. dissolved in citrate buffer(pH4.5). The ethanol extract of Platycodon grandiflorum root was orally administrated once a day for 7 days. The contents of serum glucose, triglyceride(TG) and total cholesterol were significantly decreased(p<0.05) in Platycodon grandiflorumt root treated group compared to the those of STZ-control group. Also the contents of hepatic glycogen and HDL-cholesterol, the activities of glucose-phosphate dehydrogenase(G-6-PDH) and glucokinase(GK) were significamtly increased (p<0.05). These results indicated that ethanol extract of Platycodon grandiflorum root would have antidiabetic effect in STZ-induced diabetic rats.

• Korean Journal of Microbiology
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• v.19 no.2
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• pp.63-77
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• 1981

The growth rate of yeast population (Saccharomyces uvarum) cultivated in the Knopp's modified medium (plus various carbon sources) appeared the highest value when the Knopp's minimal medium was treated to 1.5% with disaccharide such as maltose and sucrose. Also the treatment of lactose and raffinose resulted in polulation growth as to the population size in case of maltose and sucrose. However, the gorwth of yeast was not occurred at all when a polysaccharide, such as inulin, was added as carbon source. The growth from of yeast population in Knopp's modified medium are characterized by the fact that log phase continued 100hrs after inoculation and that stationary state phase appeared in general 250hrs after inoculation. Applying the various carbon sources to respiration substrate for yeast cell, the respiration rate of yeast showed the highest value in treatment of maltose and followed in order of raffinose, lactose, glucose, and sucrose. Determined the amount of poly-phosphate and turn over pathway of poly-phosphate according to culture phase of yeast, it is revealed that the yeast synthesized 3 types of poly phosphate (poly-P A,B, and C) and postulated that turn over pathway of poly-phosphate as follows ; Inorganic phosphate is converted into each kind of polyphosphates, and then one part of poly-P-C is converted into poly-P-B, the rest poly-p-C and poly-P-B are converted into poly-P-A. The synthesized poly-phosphate is considered to have a role as energy pool utilizing to synthesis of cellular organic materials. Of the 13 carbon sources used in this experiment, the useful carbon sources for biosynthesis of poly-phosphate and cellular organic materials are confirmed as disaccharide (maltose and sucrose) as well as glucose. Protein synthesis in yeast cell showed the two peaks on 6th and 8th day after inoculation ; nucleic acid on 2nd day (48hrs), carbohydrates on 2nd day (48hrs), and phospholipid on 2nd and 8th day after inoculation, respectively.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.41-45
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• 1993

Rescently we are interested in the biosurfactant. Biosurfactant have a low toxcity and easily biodegradable compound. Pseudomonas sp. 13 was isolated from soil. This microorganism produced biosurfactant that consists of glycolipid R-1 and R-2. A time course study of fermentation indicated that the appearance of glycolipid in the fermentation broth the commencement of the stationary phase with the respect to biomass. The effect of variation of the media components such as amount of glucose, nitrogen, phosphate and metal ions has been investigated. The following values found to be optimum for biosurfactant production (glucose, $20g/{\ell}$; carbon to nitrogen ratio, 40; carbon to phosphate, 18; $FeSO_4{\cdot}7H_2O\;20mg/{\ell}$).

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.15-24
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• 2005

Enterobacter intermedium oxidizes glucose to gluconic acid and sequentially converts gluconic acid to 2-ketogluconic acid (2-KGA) under aerobic condition. Shaking incubation of E. intermedium in a broth medium containing 22.5 g glucose, 8.2 g gluconic acid and 40 g rock phosphate per liter resulted in $1028mg\;L^{-1}$ soluble phosphate. The culture broth was used as phosphate bio-fertilizer (PBF) in this experiment. To evaluate PBF produced by E. intermedium on lettuce growth, five treatments (PBF1/3, PBF2/3, PBF3/3, BP, and MF) were used. In MF and BP treatments, $P_2O_5$ 5.9 kg of mineral fertilizer per 10a was added, while in PBF1/3, PBF2/3, and PBF3/3 treatments, culture broth containing one third, two third, and same amount of soluble $P_2O_5$ 5.9 kg per 10a was applied, respectively. At 20, 35, and 50 days after transplanting of lettuce, plant growth components, biomass, enzyme activities and soil chemical properties were analyzed. Dehydrogenase activity and available phosphate concentration of rhizosphere in phosphate bio fertilizer treatments (PBF1/3, PBF2/3, PBF3/3) were generally higher compared to MF and BP treatments. Soil biomass in PBF3/3 treatment was significantly higher than MF and BP treatments at early growth stage. However, there was no significant difference among all treatments with time. Plant fresh weights in PBF1/3, PBF2/3, and MF treatments were better than those in BP and PBF3/3 treatments. However, in PBF2/3 treatment the highest fresh weight was discovered where alkaline phosphatase activity was generally higher than other treatments at 35 and 50 days. Enhancement of lettuce growth at 35 and 50 days in PBF2/3 treatment was associated with greater phosphate uptake in lettuce tissue. As regarding all results, PBF showed better lettuce growth compared to mineral phosphate fertilizer where PBF2/3 treatment resulted in increase of lettuce fresh weight by 23% and phosphate uptake by 50%.

• Food Science and Preservation
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• v.30 no.1
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• pp.132-145
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• 2023

In this study, culture conditions were optimized to confirm the feasibility of Acetobacter pasteurianus as a starter for fermentation vinegar. Acetobacter pasteurianus strain can be used as a food ingredient. The optimal temperature and pH conditions of the selected Acetobacter pasteurianus SRCM101388 were 28℃ and pH 6.00, respectively. The response surface methodology (RSM) was used to optimize the composition of the medium, and Plackett-Burman design (PBD) was used to obtain the effective selection of culture medium, resulting in that glucose, sucrose, and yeast extract had the highest effect on increasing biomass. The optimal concentration, which was performed by central composite design (CCD), were determined to be 10.73 g/L of glucose, 3.98 g/L of sucrose, and 18.73 g/L of yeast extract, respectively. The optimal concentrations of trace elements for the production of biomass were found to be 1 g/L of ammonium sulfate, 0.5 g/L of magnesium sulfate, 2 g/L of sodium phosphate monobasic, 2 g/L of sodium phosphate dibasic, and the final optimized medium was pH 6.10. When incubated in a 5 L jar fermenter, the SRCM101388 strain showed a faster-dissolved oxygen (DO) reduction at a lower agitation rate (rpm), and it was able to grow even at reduced DO level when aeration was maintained. The amount of final biomass produced was 2.53±0.12×10⁹ CFU/mL (9.40±0.02 log CFU/mL) when incubated for 18 hours at 150 rpm, 0.5 vvm, pH 6.0, and 28℃.