Biomedical subjects

M Takagi

Publications and source records attributed to M Takagi.

At least 271 records · Page 15Linked to original sources

PubMed1999

[An early-onset case of acute disseminated encephalomyelitis with bilateral thalamic lesions on MRI].

We report the case of 5-year-old girl with acute disseminated encephalomyelitis (ADEM), whose MRI showed bilateral thalamic lesions. She suffered from left optic neuritis and generalized convulsion. Examination of cerebrospinal fluid revealed elevation of mononuclear cells and myelin basic protein (MBP). MRI showed the swelling of left optic nerve and high intensity areas of bilateral thalamus. After methylprednisolone pulse therapy, her visual acuity was dramatically improved and bilateral thalamic lesions were decreased. In childhood, bilateral thalamic lesions were observed in several diseases, such as viral encephalitis. Reye syndrome, Leigh syndrome and acute necrotizing encephalopathy. Demyelinating diseases involving the grey matter were very rare, but we must consider the presence of symmetrical thalamic involvement in patients with ADEM.

Child, Preschool↗

PubMed1999

[Two cases of sporadic juvenile Parkinson's disease caused by homozygous deletion of Parkin gene].

Parkin gene, which is one of the causes of familial Parkinson's disease, was cloned in 1998, and it was found that mutations of this gene induces familial Parkinson's disease of autosomal recessive form (AR-JP). Clinical studies have revealed that almost cases of AR-JP are consanguineous or hereditary. However, AR-JP may also be caused by marriage between two carriers. We therefore investigated the existence of a homozygous deletion in the parkin gene in 10 patients with juvenile Parkinson's disease with the onset of age younger than 40 years without consanguinity or heredity. A large delection of the gene was found in 2 of the 10 patients with sporadic Parkinson's disease, and both of these deletion were exon 4. The present study clearly suggests that juvenile Parkinson's disease in Japan may be caused by abnormalities in parkin gene regardless of family history or consanguinity.

Age of Onset↗

PubMed1999

Two different components of contingent negative variation (CNV) and their relation to changes in reaction time under hypobaric hypoxic conditions.

BACKGROUND: Acute hypoxic conditions cause deterioration of the higher cerebral functions. The contingent negative variation (CNV), which represents both psychological and motor functions, is useful in evaluating cerebral functions. However, few attempts have been made to understand CNV change, especially for components under acute hypoxic conditions. HYPOTHESIS: If recognition of stimulus is affected by acute hypoxic conditions, the CNV response may be decreased and reaction times (RTs) may be prolonged. In addition, the differing effects of hypoxia on the early and late CNV would be demonstrated. METHODS: Hypobaric hypoxic conditions at altitudes of 0-6000 m were simulated in an experimental decompression chamber, at a decompression speed of 110 m x min(-1). Peak amplitudes of the entire, early and late CNV were measured at each altitude together with RT measurements. RESULTS: At 6000 m, the complete CNV decreased significantly compared with that at 0 m (p<0.01). Early CNV also showed a significant decrease (p<0.05), but there was no significant change in late CNV. The RTs were prolonged significantly at 5000 and 6000 m (p<0.05, p<0.01). At the altitudes of 3000 and 0 m, a negative correlation between the peak amplitude late CNV and the RT was recognized statistically (p< 0.01), while at 4000 m and above, it was rather the early CNV and the RT that were negatively correlated (p<0.01). CONCLUSIONS: With interstimulus intervals of 2 s, acute hypoxia served to reveal the functional properties of the early and late components of CNV. CNVs may be regarded as good indexes of higher cerebral function under hypoxic conditions.

Acute Disease↗

PubMed1998

Studies on cycloheximide-sensitive and cycloheximide-resistant ribosomes in the yeast Candida maltosa.

Cycloheximide sensitivity or resistance in yeast is under the control of genes encoding different forms of ribosomal protein L41. In our previous studies, we have shown by isolating L41-Q1a, L41-P1a and their respective allelic genes, L41-Q1b and L41-P1b, from the partial diploid genome of C. maltosa, that this species, which is inducibly resistant to CYH, has both types of the L41 genes and that the expression of at least one of the L41-Q genes is induced by CYH, whereas L41-P genes are constitutively expressed. Here, we have identified another L41 (L41-Q2a), its allelic gene (L41-Q2b) and a third gene (L41-Q3) from the genome of C. maltosa. By gene disruption experiments, we now show that L41-Q1a and L41-Q1b are not responsible for the resistance to CYH and that the DeltaL41-Ps strain, which has only functional L41-Q genes, shows constitutive resistance to CYH, but grows more slowly than the DeltaL41-Qs strain, which has only functional L41-P genes, in the absence of CYH. Our results also show that in vitro, ribosomes containing L41-Q-type are less active in translation than those containing L41-P-type, although only the former ribosomes are active in the presence of CYH. These data suggest that ribosomes containing L41-Q-type are less active under normal growth conditions, but that this activity is not affected in the presence of CYH. We discuss the possible multi-step evolutionary event(s) by which C. maltosa has acquired the property of inducible resistance to CYH.

Amino Acid Sequence↗

PubMed1998

Isolation of a class IV chitin synthase gene from a zygomycete fungus, Rhizopus oligosporus.

We found the presence of DNA sequence which shows sequence similarity to the class IV chitin synthase gene (CHS3) of Saccharomyces cerevisiae in the genome of 14 Rhizopus species which belong to zygomycetes. We cloned a gene (chs3), which might correspond to one of these homologous sequences, from Rhizopus oligosporus by low stringency plaque hybridization probed with CHS3. The deduced amino acid sequence of this gene showed highest similarity to the class IV chitin synthase of Neurospora crassa (46.7% identity over 1087 amino acids), showing that this gene encodes a class IV chitin synthase. Northern analysis revealed the differential expression pattern of this gene in the asexual life cycle with highest expression in the early stage of asexual spore formation. This is the first report of the isolation and analysis of a class IV chitin synthase gene from zygomycete fungi.

Amino Acid Sequence↗

PubMed1998

Hybrid artificial lung with interleukin-10 and endothelial constitutive nitric oxide synthase gene-transfected endothelial cells attenuates inflammatory reactions induced by cardiopulmonary bypass.

BACKGROUND: Recently, the research on hybrid artificial organs such as heart, liver, and kidney has been reported to yield new possibilities for clinical use. However, there have been few reports on the practical use of a hybrid artificial lung, primarily due to difficulties in the concept for its application and techniques for cell attachment. In this study, we investigated the possibility for developing a novel strategy: a hybrid artificial lung with constitutive nitric oxide synthase (NOS) and interleukin (IL)-10 gene-transfected endothelial cells to attenuate inflammatory reactions induced by cardiopulmonary bypass. METHODS AND RESULTS: First, we performed an in vitro study to confirm the efficacy of our gene transfection into endothelial cells. Constitutive nitric oxide synthase and IL-10 cDNA were transfected into endothelial cells according to the hemagglutinating virus of Japan-liposome method. Levels of nitric oxide released from the endothelial constitutive NOS (ecNOS)-transfected endothelial cells were significantly higher than those of control cells (24 hours after the stimulation by lipopolysaccharide: 284.5 +/- 54.0 versus 95.7 +/- 27.9 mumol/L, P = 0.0001). On the other hand, IL-8 levels in the transfected endothelial cells were significantly lower than those in the control group (48 hours after stimulation by tumor necrosis factor-alpha: 3.1 +/- 2.4 versus 62.1 +/- 1.3 ng/mL, P = 0.0002), and IL-10 was detected in the transfected group but not in the control group. Next, we performed an in vivo study to evaluate the possibility of developing a hybrid artificial lung. One-hour partial cardiopulmonary bypass with this lung was established in rats undergoing femorofemoral bypass. Artificial lungs with no cells (group C; n = 5), that were coated with untreated endothelial cells (group E; n = 5), or that were coated with ecNOS and IL-10 gene-transfected endothelial cells (group T; n = 3) were used. At 45 minutes after the initiation of cardiopulmonary bypass, group T showed higher nitric oxide levels than groups C and E (T versus C versus E: 75.2 +/- 6.8 versus 67.2 +/- 4.3 versus 68.6 +/- 5.2 mumol/L, P = NS). The serum IL-8 levels just after cardiopulmonary bypass in group T were significantly lower than those in group C (1728 +/- 282 versus 4275 +/- 145 pg/mL, P = 0.0151). The Pao2 levels in group T just after weaning from cardiopulmonary bypass were significantly higher than those in group C (271.3 +/- 41.7 versus 136.6 +/- 12.3 mm Hg, P = 0.0362). CONCLUSIONS: These results demonstrate that a hybrid artificial lung with IL-10 and ecNOS gene-transfected endothelial cells inhibited IL-8 release and increased nitric oxide production. This suggests the possibility of developing a hybrid artificial lung capable of preserving native lung function by attenuating cardiopulmonary bypass-induced inflammatory reactions via inhibition of IL-8 release and enhanced nitric oxide production.

Animals↗

PubMed1998

Crystallization and preliminary X-ray crystallographic analysis of archaeal O6-methylguanine-DNA methyltransferase.

Crystals of archaeal O6-methylguanine-DNA methyltransferase (MGMT) from hyperthermophilic archaeon Pyrococcus kodakaraensis strain KOD1 have been grown at room temperature using polyethylene glycol as a precipitant. The diffraction pattern of the crystal extends to 2.0 A resolution at room temperature upon exposure to Cu Kalpha radiation. The crystal belongs to the space group P212121 with unit-cell dimensions of a = 52.8, b = 86.6 and c = 39.9 A. The presence of one molecule per asymmetric unit gives a crystal volume per protein mass (Vm) of 2.3 A3 Da-1 and a solvent content of 48% by volume. A full set of X-ray diffraction data was collected to 2.0 A Bragg spacings from the native crystal.

Bacterial Proteins↗

PubMed1998

Defective control of apoptosis, radiosensitivity, and spindle checkpoint in ataxia telangiectasia.

We examined the regulation of apoptosis, radiosensitivity, and spindle checkpoint in response to DNA-damaging agents in ataxia telangiectasia (AT)-derived lymphoblastoid cell lines (AT-LCLs), which lack AT mutated (ATM) protein expression. In addition to the previous findings that AT-LCLs are defective in regulation of cell cycle at the G1, S, and G2-M checkpoints in response to X-ray irradiation (X-IR) and are highly sensitive to X-IR (J. Biol. Chem., 271: 20486-20493, 1996), we showed for the first time that AT-LCLs were defective in X-IR-associated spindle checkpoint control. The cells were also resistant to early apoptosis as much as LCLs derived from patients with Li-Fraumeni syndrome (LFS-LCLs). Terminal deoxynucleotidyl transferase-mediated nick end labeling assay of LCLs, however, demonstrated a significant increase in apoptotic cells among AT-LCLs cultured over a longer period after X-IR. These findings were in contrast to those of LFS-LCL, which showed very little increase in terminal deoxynucleotidyl transferase-mediated nick end labeling-positive population, even in cells with hyperploidy. Thus, although early apoptosis and cell cycle controls in response to DNA damage are disrupted in both ATM and p53 mutations, cells from AT patients are much more susceptible to late-onset apoptosis than those of LFS. These differences may depend on the level of accumulation of DNA damage and/or threshold that triggers late-onset cell death in ATM or p53 mutations. Our findings allow a better understanding of the role of ATM in p53-dependent and independent signal transduction pathways in response to DNA damaging agents.

Apoptosis↗

PubMed1998

Relation between evolutionary distance and enzymatic properties among the members of the CYP52A subfamily of Candida maltosa.

The CYP52A subfamily of the alkane-assimilating yeast Candida maltosa consists of six structurally related isoforms. Four of them (CYP52A3, 4, 5, and 9) are strongly induced by alkanes and play an important role for the conversion of various alkanes and fatty acids. Taking advantage of a homologous overexpression system, we found in the present study that both of the two other CYP52A forms, CYP52A10 and CYP52A11, represent specialists for the hydroxylation of lauric acid suggesting their preference for short-chain fatty acids. At the same time, they hydroxylated palmitic acid only moderately and failed to convert hexadecane. Based on the now completed knowledge about the principal substrate specificities of all members of the CYP52A subfamily of C. maltosa, it became apparent that evolutionarily more distantly related P450 forms developed either to alkane or to fatty acid hydroxylases, whereas P450 forms which retained the ability to convert both types of substrates were also found to be evolutionarily related to both alkane and fatty acid hydroxylases.

Candida↗

PubMed1998

Incorporation of extracellular phospholipids and their effect on the growth and lipid metabolism of the Saccharomyces cerevisiae cho1/pss mutant.

The cho1/pss mutant of Saccharomyces cerevisiae, which is auxotrophic for choline or ethanolamine because of the deficiency in phosphatidylserine synthesis, grew in the presence of 0.05 mM phosphatidylcholine (PC) with octanoic acids (diC8PC) or decanoic acids (diC10PC), but not in the presence of PC with longer acyl residues. It did not grow in the presence of the soluble hydrolytic products of PC, phosphorylcholine or glycerophosphorylcholine, at comparable concentrations. Addition of 10 mM hemicholinium-3, a choline transport inhibitor, or disruption of the CTR gene, which encodes a choline transporter, inhibited the growth of the cho1/pss mutant in the presence of choline, but not in the presence of 0.1 mM diC8PC. Under diC8PC-supported growth conditions, octanoic acid was barely detectable in the cellular phospholipid fraction, but was recovered in the culture medium as the free acid, and the phosphatidylethanolamine (PE) content was low in comparison to the choline-supported conditions. These results suggest that PCs with short acyl residues were taken up by the cho1/pss mutant and remodeled as they were used, and that PCs with short acyl residues do not inhibit conversion of PE to PC. The current results provide a new direction in the analysis of intracellular phospholipid movement and metabolism in yeast.

Caprylates↗

PubMed1998

Characterization of two intein homing endonucleases encoded in the DNA polymerase gene of Pyrococcus kodakaraensis strain KOD1.

Two intein endonucleases, denoted PI- Pko I and PI- Pko II, in the DNA polymerase gene of the hyperthermophilic archaeon Pyrococcus kodakaraensis KOD1 were expressed in Escherichia coli and the recombinant endonucleases were characterized. Both endonucleases were thermostable and cleaved their intein-less DNA sequences leaving four base 3'-hydroxyl overhangs. PI-Pko I exhibited 22 times higher specific activity than PI-Pko II and the activity of PI-Pko II was enhanced at higher potassium ion concentrations (1 M). Recognition sequences were also determined using synthetic oligonucleotides inserted into plasmid pUC19. It was shown that DNA sequences of 19 and 16 bp are needed for cleavage by PI-Pko I and PI-Pko II, respectively. PI-Pko II could cleave the downstream junction region between intein-encoding and mature DNA polymerase regions and cleavage by PI-Pko II could be detected even when chromosomal DNA of P.kodakaraensis KOD1 was used as substrate. Therefore, it is suggested that these endonucleases are switching endonucleases whose function lies in the rearrangement of chromosomal DNA.

Archaeal Proteins↗

PubMed1998

In vitro heat effect on heterooligomeric subunit assembly of thermostable indolepyruvate ferredoxin oxidoreductase.

Indolepyruvate ferredoxin oxidoreductase (IOR) from hyperthermophilic archaeon Pyrococcus kodakaraensis KOD1 catalyzes the oxidative decarboxylation of arylpyruvates by forming a heterooligomeric complex (alpha2beta2). The genes iorA and iorB which encode respective alpha and beta subunits, were coexpressed heterologously in Escherichia coli cells under anaerobic conditions. IOR activity was detected from the cell extract containing both subunits and its activity was enhanced by in vitro heat treatment prior to the assay. The iorA and iorB were expressed individually and each subunit was examined for enzymatic activity with and without heat treatment. IOR activity was detected neither from the extract of alpha subunit nor beta subunit. The alpha and beta subunits were mixed and then IOR activity was examined. Weak IOR activity was detected without heat treatment, however, upon heat treatment its activity was enhanced. The mixture of individually heat treated alpha and beta subunits did not possess any IOR activity even though the mixed sample was heat treated again. IOR alpha and beta subunits were individually purified to homogeneity, mixed with or without heat treatment and subunit assembly was examined by determining molecular mass. Upon heat treatment, inactive alpha and beta were converted to an active high molecular weight complex (195 kDa) which corresponds to the alpha2beta2 structure. However, the active complex was not formed without heat treatment, suggesting that high temperature environments are important for the heterooligomerization of IOR subunits.

Base Sequence↗

PubMed1998

Mutual conversion of fatty-acid substrate specificity by a single amino-acid exchange at position 527 in P-450Cm2 and P-450Alk3A.

The two eukaryotic fatty-acid hydroxylases P-450Cm2 and P-450Alk3A, which represent CYP52A4 variants naturally occurring in the yeast Candida maltosa, were characterized with respect to their substrate specificity. Whereas P-450Cm2 was found to catalyse lauric acid omega-hydroxylation with greater efficiency, P-450Alk3A had higher palmitic acid turnover numbers compared to P-450Cm2, resulting in ratios of lauric acid to palmitic acid turnover rates of nearly 11 and 3 for P-450Cm2 and P-450Alk3A, respectively. As shown by means of chimeric enzymes and site-directed mutagenesis, the key residue determining these differences in substrate specificity was found to be a single amino acid at position 527. Interestingly, the mutual exchange of valine (P-450Cm2) and leucine (P-450Alk3A) led to a direct transposition of specificity, suggesting that amino acids at this site may determine the efficiency of fatty-acid hydroxylation relatively independently of other active-site residues. This was further supported by the finding that P-450Cm2 and P-450Alk3A with methionine at position 527 displayed almost identical hydroxylation activities. Moreover, methionine to leucine substitutions at the corresponding alignment position in P-450Cm1 (CYP52A3), P-450Alk2A (CYP52A5) and P-450Alk5A (CYP52A9) altered the fatty-acid specificity of these enzymes. In comparison to the structure of the bacterial P-450BM3 (CYP102), we propose that the amino acid at position 527 may serve to close the substrate-binding pocket near to the haem in the fatty-acid-omega-hydroxylating P-450 of the CYP52 family.

Amino Acid Sequence↗

PubMed1998

Ion pairs involved in maintaining a thermostable structure of glutamate dehydrogenase from a hyperthermophilic archaeon.

Intersubunit ion pairs are considered to be involved for maintaining a stable structure of the glutamate dehydrogenase (GDH) from hyperthermophiles. In order to demonstrate an effect of intersubunit ion pairs on the structural stability, two kinds of mutation (T138E, Thr at position 138 was replaced by Glu; E158Q, Glu at position 158 was replaced by Gln) which add and remove ion pairs, respectively, were introduced into Pk-gdhA gene encoding GDH from Pyrococcus kodakaraensis KOD1. Addition of one ion pair (Pk-GDHA-T138E) increased the optimum temperature and thermostability. In contrast, Pk-GDH-E158Q showed lower optimum temperature and less thermostability than wild type GDH. Structure analysis of GDHs was performed by circular dichroism (CD) and indicated that all recombinant enzymes (Pk-GDH, Pk-GDH-T138E, Pk-GDH-E158Q) possess different structures from that of natural GDH. Upon heat treatment (60 degrees C, 2 h), the structures of Pk-GDH and Pk-GDH-T138E were converted to another form close to the natural structure. However, no structural conversion by heat treatment was observed in Pk-GDH-E158Q. These results indicate that intersubunit ion pairs play an important role in forming thermostable structure of Pk-GDH.

Amino Acid Sequence↗

PubMed1998

Measurement of early pregnancy factor activity for monitoring the viability of the equine embryo.

The viability of embryos before flushing from donor mares (n = 5) and after transfer to recipient mares (n = 7) was monitored in mare serum by detecting early pregnancy factor (EPF) using the rosette inhibition test (RIT). The EPF activity was measured in donor mares before and after natural mating at natural estrus; after ovulation on Days 2, 5 and 8; and after embryo flushing (Day 8) on Days 8, 9, 10 and 13 after ovulation. The collected embryos were transferred immediately after flushing. The EPF activity in recipient mares were measured on the day of transfer and after embryo transfer on Days 1, 2, 3 and 5. Pregnancy was confirmed on Day 12 to 14 after embryo transfer. The mean EPF activity of donor mares was increased to the pregnant level (> an RI titer score of 10) on Day 2 after ovulation. Two days after flushing the embryos, the EPF activity of donor mares had decreased to the nonpregnant level. Among the 7 recipient mares, 3 mares were diagnosed pregnant on Day 12 after embryo transfer with ultrasound. The EPF activity of the pregnant recipient mares was increased above the minimum level observed in pregnant mares on Days 2 to 3 after transfer. However, among the nonpregnant recipient mares after embryo transfer, the EPF activity of 3 mares remained at the pregnant level only 2 to 3 d and then declined to the nonpregnant level. In one recipient mare, EPF activity did not reach the pregnant level throughout the sample collection. The results of this study indicated that equine EPF can be detected in serum of pregnant mares as early as Day 2 after ovulation. From our observation, we conclude that the measurement of EPF activity is useful for monitoring the in vivo viability of equine embryos and early detection of embryonic death.

Animals↗

PubMed1998

Evaluation of fluids from cystic follicles for in vitro maturation and fertilization of bovine oocytes.

Follicular cysts are defined as cystic structures derived from unovulated follicles. The formation of the cysts appears to be related to failure of the oocyte to resume meiosis. The aim of this study was to evaluate in the bovine: 1) the ability of the fluid from cystic follicles to promote in vitro oocyte maturation and fertilization, 2) the predictive value of the morphology of oocytes derived from cystic follicles on the ability of the follicular fluid to promote in vitro maturation/fertilization as well as the oocytes to undergo maturation and fertilization. In Experiment 1, the ability of fluid from cystic (and normal) follicles from live and slaughtered cows (to promote) in vitro maturation and fertilization of bovine cumulus-oocyte-complexes (COC's) was assessed by cumulus expansion, sperm penetration, male pronucleus formation and polyspermy rates. Concentrations of progesterone (P4) and estradiol-17 beta (E2) were measured in the fluid from cystic follicles collected from live and slaughtered cows. In Experiment 2, we investigated the relationship of the morphology of COC's from cystic follicles, and the effect of the follicular fluids on oocyte maturation as well as P4 and E2 concentrations. In Experiment 1, although sperm penetration and male pronucleus formation were inhibited significantly by fluid from some cystic follicles collected from live and slaughtered cows, there were no significant differences in sperm penetration, male pronucleus formation and polyspermy rates between fluid from cystic follicles collected from live cows, from slaughtered cows and from control groups, regardless of the P4/E2 ratio. In Experiment 2, the morphology of cumulus-oocyte complexes from cystic follicles varied and the pronucleus formation of oocytes after in vitro fertilization was abnormal. On the other hand, the male pronucleus formation rates were not significantly different between the cystic follicular fluids and control, regardless, of the P4/E2 ratio. The results of this study suggest that many of the bovine follicular fluids from cystic follicles possess the ability to induce cumulus expansion, nuclear maturation and male pronucleus formation following in vitro maturation and fertilization of bovine oocytes. The morphology of the cumulus-oocytes complexes from cystic follicles seems not to relate to the ability of the cystic follicular fluids to induce oocyte maturation, and oocytes from cystic follicles possess the ability to form male pronucleus even though most were abnormal after in vitro fertilization.

Animals↗

PubMed1998

A selective switch-on system for self-renewal of embryonic stem cells using chimeric cytokine receptors.

Propagation of embryonic stem (ES) cells with an undifferentiated pluripotential phenotype depends on leukemia inhibitory factor (LIF). The LIF receptor complex is composed of a heterodimer of LIF receptor alpha (LIFR alpha) and gp130. To activate LIFR signaling pathways independently from endogenous ones, we constructed chimeric receptors by linking the extracellular domain of human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor alpha or beta (hGMR alpha or beta) to the transmembrane and cytoplasmic regions of either mouse LIFR alpha or gp130. hGMR alpha-mLIFR/hGMR beta-mgp130 or hGMR alpha-mgp130/hGMR beta-mgp130, but not hGMR alpha-mLIFR/hGMR beta-mLIFR, preserved the self-renewal activity in A3 ES cells. All of these chimeric receptors were phosphorylated after hGM-CSF stimulation without phosphorylation of endogenous gp130. Phosphorylation of the signal transducer and activator of transcription 3 through chimeric receptors correlated with the undifferentiated phenotype. Therefore, these chimeric receptors prove useful to analyze mechanisms of the self-renewal of ES cells.

Animals↗

PubMed1998

Metabolism analysis and on-line physiological state diagnosis of acetone-butanol fermentation.

Fermentation equations for acetone-butanol (AB) were applied in a metabolic analysis of the reaction network under various conditions; that is, at different pHs and a high NADH2 turnover rate using methyl viologen, in a Clostridium acetobutylicum culture. The results disclosed variations in the pattern of rate changes that reflected changes in the physiological state. A linear relationship was found to exist between NADH2 generation and butanol production rate. By coupling an automated measurement system with the fermentation model, on-line estimation of the culture state was accomplished. Based on the AB fermentation model, new parameters were defined for on-line diagnosis of the physiological state and determination of the best timing for amplifying NADH2 generation by the addition of methyl viologen to obtain a high level of butanol productivity. A potential means of achieving optimal control for a high level of solvent production, involving the correlation of certain rates, is proposed.

Acetone↗