• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.85-91
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• 1994

The characteristcs of monascus fermentation using a hyperpigment-producing mutant, Monascus sp. J101, were analyzed, and the extractive fermentations employing permeabilizing agents and resin were carried out to increase the productivity of red pigment. And the kinetic analysis was also carried out in case of the monascus fermentation using Amberlite XAD-7. The extracellular content of the red pigment produced by Monascus sp. J101 was about 17% of the total, and the production of pigment was regulated by its own product. The cell growth reached a stationary phase at 48 hours ofter inoculation, whereas the pigment production continued up to 100 hours, which showed the pattern of a mixed growth-associated type. During the fermentation, various permeabilizing agents were added to the culture medium and their effects on pigment production were examined. By adding 0.05% Triton X-100 at 48 hours of cultivation, about an 18% increase in pigment production was accomplished as compared to the control, 12% ethyle acetate and 15% for 0.05% deoxycholate, respectively. When a nonionic adsorbent, Amberlite XAD-7 was added to the culture medium at a concentration of 12.0% at 48 hours of cultivation, the pigment production was enhanced by about 48.9% as compared to the control.

• KSBB Journal
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• v.6 no.2
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• pp.175-180
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• 1991

The quantitative effects of molecular weight and concentrations of two phase-forming polymers-polyethylene glycol and crude dextran on the two phase extractive ethanol fermentation were investigated using a Box-Wilson central composite protocol. The regression model obtained was used in order to determine optimum compositions of aqueous two phase system. In the aqueous two phase extractive ethanol fermentation of Kluyueromyces fragilis CBS 1555 with Jerusalem artichoke juice, it was found from the regression model that the variables influenlcing on ethanol fermentation were PEG concentration, time, Dx concentration, and PEG molecular weight strongly in order. The interaction of PEG concentration and PEG molecular weight was also found, and the effect of PEG concentration decreased with increase in molecular weight of PEG. The ethanol concentration incresed with increase in molecular weight of PEG, and with decrease in concentration of PEG. In conolusion, maximum concentration of ethanol produced was obtained at the following compositions; PEG MW 20000, Dx concentration ranged from 4% to 5%, and PEG concentration ranged from 3% to 7%.

• KSBB Journal
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• v.8 no.2
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• pp.178-184
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• 1993

Extractive fermentations with the extract of Jerusalem artichoke in an aqueous-two-phase-system of polyethyleneglycol(PEG) and dextran(Dx) were investigated to obtain the effects of composition of PEG and Dx on both fermentation ,characteristics and partition ratio of alcohol. The specific growth rate of K. Fraglis CBS 1555 increased with a decrease of concentration of PEG and Dx. It augmented along with concentration of initial sugar up to 80g/l but decreased thereafter. The specific production rate of alcohol showed a rising tendency up to 100g/lof initial sugar, whereafter represented a decreasing trend. The partition ratio of alcohol between two phases augmented according to decrease of Dx comic. and increase of PEG cone. regardless of initial sugar concentrations. The ratio, however, decreased with Increment of initial sugar concentration at constant composition of PEG and Dx. The partition coefficient of alcohol had an ascending effect to the increase of PEG cone, but it had little effect on the changes of concentrations of Dx and initial sugar. The present study suggests that the optimum composition of PEG and Dx in the aqueous-two-phase-system by extractive fermentation were around 6.5%(w/v) of PEG and 3%(w/v) of Dx in considerations of emulsion state, sedimentation and separation of two phases, alcohol partition ratio, and specific growth rate.

• KSBB Journal
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• v.17 no.6
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• pp.566-570
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• 2002

In lactic acid fermentation, the end product inhibition by lactic acid causes several problems. The most important of which are low lactate formation rate and its recovery from fermentation broth. To overcome these problems, extractive lactic acid fermentation was carried out in a bioreactor, which was connected to a column packed with anion exchange resin (Amberlite IRA-400, 250 g). The system was started as a batch process, and then the separation process was started when the lactic acid concentration reached 10 g/L, 20 g/L or 30 g/L. In each case, total lactic acid concentration was reached to 48.6, 53.6, 52.6 g/L with its productivity of 1.2 g/L $.$ h, 1.6 g/L $.$ h, and 1.3 g/L $.$ h, respectively Especially, in the case of the 20 g/L recycling-initiation process, extractive fermentation reduced tie fermentation time (17 hrs) by 34% in comparison with the conventional batch process. The direct consequence of this time reduction was shown by a 1.8 fold increase in overall lactic acid productivity.

• Microbiology and Biotechnology Letters
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• v.22 no.5
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• pp.531-537
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• 1994

This study was undertaken with objective of optimizing the conditions of fermentation in an aqueous two-phase system which is composed of polyethylene glycol (PEG) 20000 and crude dextran (Dx). The data were obtained and analyzed using the Box-Wilson's experimental design protocol and the response surface methodology. To reach this end a multilinear polynomial regres- sion model was developed, which can be utilized for the purpose of optimizing the extractive fermentation. Optimum conditions for batch fermentation with aqueous two phase system were found to be at 4.2~5.4% PEG/3.2~4.2% Dx range. The composition of the center was 4.8% PEG/ 3.6% Dx. Optimum operating conditions for initial sugar concentration and fermentation time were approximately 160 g/l, and 21~22 hr, respectively. Fermentation in the aqueous two phase system composed of 5% PEG/4% Dx showed increase of 23% in ethanol concentration, of 9.5% in ethanol yield, and of 19% in ethanol productivity as compared to the case of fermentation of neat Jerusalem artichoke juice.

• Biotechnology and Bioprocess Engineering:BBE
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• v.4 no.1
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• pp.1-11
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• 1999

Considerations of partition coefficients, selectivity, biocompatibility, and waste generation are important in selection of appropriate solvents to be used for extractive recovery of products from fermentation broths. Several selection criteria can be used based upon the nature of different species present in the broth. These criteria, along with examples of specific case studies, were presented. These serve not only in screening of useful solvents, but also in pointing to the specific modes of operation of recovery-coupled bioprocesses.

• Journal of Microbiology and Biotechnology
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• v.29 no.6
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• pp.897-904
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• 2019

Monascus purpureus recombinant mppC and mpp7 knockout strains were subjected to extractive fermentation in the context of azaphilone pigment production. Inclusion of Diaion HP-20 resin resulted in the selective production of unreduced azaphilone congeners, in addition to the early intermediate FK17-P2a, from ${\Delta}mppC$ and ${\Delta}mpp7$ strains that would otherwise mainly produce reduced congeners. Structural determination of two novel unreduced azaphilones from the ${\Delta}mpp7$ strain was accomplished. The unreduced azaphilone compound was converted into the cognate reduced congener in recombinant M. purpureus strains, demonstrating its intermediate role in azaphilone biosynthesis. This study demonstrates the possibility that extractive fermentation with Diaion HP-20 resin can be used to obtain cryptic azaphilone metabolites.

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.327-334
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• 2018

Monascus is a source of food colorant with high productivity of the pigment azaphilone. Monascus azaphilone (MAz) is biosynthesized through a single non-reducing polyketide pathway, the major components of which are ankaflavin (1), monascin (2), rubropunctatin (3) and monascorubrin (4); valuable biological activities have been reported for these compounds. Thus, various culture conditions were explored to reduce the cost of culture ingredients, enhance productivity and modulate compound composition. In the present study, we examined an extractive fermentation (EF) method with Diaion HP-20 resin (HP20) in direct comparison to a previously explored method involving Triton X-100 (TX100) to explore the modulated production of the major MAzs. We employed wild-type Monascus purpureus as well as two derivative recombinant strains (${\Delta}mppG$ and ${\Delta}mppE$) that are known to have differential MAz profiles as that of the wild-type strain. The HP20 resin was capable of modulating the MAz profile in favor of orange MAzs 3 and 4, oxidized congeners in this class, as was TX100-a phenomenon not previously observed for TX100 EF with Monascus anka. These finding substantiate that HP20 can be employed for the selective production of oxidized MAz and for diversifying the culture conditions used for Az production.

• KSBB Journal
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• v.15 no.4
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• pp.380-387
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• 2000

An extractive fermentation process using pervaporation was studied in a 7 liter fermentor. Pervaporation was performed using a silicone membrane module and a low-acid-producing strain Clostridium acetobutylicu, B18 was used to produce butanol. In batch culture without pervaporation pH 5.5 and initial glucose concentration of 60 g/L resulted in the highest butanol productivity (0.216 g/L$.$h) with butanol yield of 0.261 Butanol flux through the membrane was best at 2.0 L/min-tubing of air flow rate In batch and fed-batch fermentation glucose consumption rate increased by 1.3 times with pervaporation.

• KSBB Journal
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• v.15 no.5
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• pp.458-463
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• 2000

Production of acetic acid from cellulosic biomass by Simultaneous Saccharification and Extractive Fermentation (SSEF) was investigated. The homoacetate organism used in this study was a strain of Clostridium thermoaceticum, ATCC # 49707. A batch operation of Simultaneous Saccharification and Fermentation(SSF) using ${\alpha}$-cellulose at pH 5.5 and 55$^{\circ}C$ yielded 40% conversion of cellulose to acetic acid, while a fed-batch SSF operation produced a maximum acetic acid concentration of 25 g/L, with 50% overall yield. In-situ extractive fermentation to reduce the end-product inhibition on both bacteria and enzyme was carried out. in a batch SSEF using 200 g/L IRA-400 resin, acetic acid concentration reached to 23.9 g/L and acetic acid yield and productivity were observed to be 48% and 0.20 g/L-hr, respectively.