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1.
Continuous production of lactic acid in a cell recycle reactor 总被引:3,自引:0,他引:3
Eric Ohleyer Harvey W. Blanch Charles R. Wilke 《Applied biochemistry and biotechnology》1985,11(4):317-332
The production of lactic acid from glucose has been demonstrated using a CSTR (continuous stirred-tank reactor) with cell
recycle. Studies were conducted withLactobacillus delbrueckii at a fermentation temperature of 42°C and a pH of 6.25. A cell density of 140 g dry weight/L and a volumetric productivity
of 150 g/L.h, with complete glucose consumption, were obtained. It was not possible to obtain a lactic acid concentration
above 60 g/L because of product inhibition. A cell purge was not necessary to maintain high viability bacteria culture or
to obtain a steady state. At steady state the net cell growth appeared to be negligible. The specific glucose consumption
for cell maintenance was 0.33 g glucose/g cells-h. 相似文献
2.
Wee Young-Jung Yun Jong-Sun Kang Kui-Hyun Ryu Hwa-Won 《Applied biochemistry and biotechnology》2002,98(1-9):1093-1104
Enterococcus faecalis RKY1, a fumarate-reducing bacterium, was immobilized in an asymmetric hollow-fiber bioreactor (HFBR) for the continuous production
of succinic acid. The cells were inoculated into the shell side of the HFBR, which was operated in transverse mode. Since
the pH values in the HFBR declined during continuous operation to about 5.7, it was necessary to change the feed pH from 7.0
to 8.0 after 24 h of operation in order to enhance production of succinic acid. During continuous operation with a medium
containing fumarate and glycerol, the productivity of succinate was 3.0–10.9 g/(L·h) with an initial concentration of 30 g/L
of fumarate, 4.9–14.9 g/(L·h) with 50 g/L of fumarate, and 7.2–17.1 g/(L·h) with 80 g/L of fumarate for dilution rates between
0.1 and 0.4 h−1. The maximum productivity of succinate obtained by the HFBR (17.1 g of succinate /[L·h]) was 1.7 times higher than that of
the batch bioconversions (9.9 g of succinate /[L·h]) with 80 g/L of fumarate. Furthermore, the long-term stability of the
HFBR was demonstrated with a continuously efficient production of succinate for more than 15 d (360 h). 相似文献
3.
The separation of lactic acid from lactose in the ultrafiltration permeate of cheese whey broth was studied using a cross-flow
nanofiltration membrane unit. Experiments to test lactic acid recovery were conducted at three levels of pressure (1.4, 2.1,
and 2.8 MPa), two levels of initial lactic acid concentration (18.6 and 27 g/L), and two types of nanofiltration membranes
(DS-5DK and DS-5HL). Higher pressure caused significantly higher permeate flux and higher lactose and lactic acid retention
(p<0.0001). Higher initial lactic acid concentrations also caused significantly higher permeate flux, but significantly lower
lactose and lactic acid retention (p<0.0001). The two tested membranes demonstrated significant differences on the permeate flux and lactose and lactic acid retention.
Membrane DS-5DK was found to retain 100% of lactose at an initial lactic acid concentration of 18.6 g/L for all the tested
pressures, and had a retention level of 99.5% of lactose at initial lactic acid concentration of 27 g/L when the pressure
reached 2.8 MPa. For all the test when lactose retention reached 99–100%, as much as 64% of the lactic acid could be recovered
in the permeate. 相似文献
4.
Comparison between Different Hydrolysis Processes of Vine-Trimming Waste to Obtain Hemicellulosic Sugars for Further Lactic Acid Conversion 总被引:1,自引:0,他引:1
Moldes AB Bustos G Torrado A Domínguez JM 《Applied biochemistry and biotechnology》2007,143(3):244-256
Trimming vine shoot samples were treated with water under selected operational conditions (autohydrolysis reaction) to obtain
a liquid phase containing hemicellulose-decomposition products. In a further acid-catalyzed step (posthydrolysis reaction),
xylooligosaccharides were converted into single sugars for the biotechnological production of lactic acid using Lactobacillus
pentosus. A wide range of temperatures, reaction times, and acid concentrations were tested during the autohydrolysis–posthydrolysis
process to investigate their influence on hemicellulose solubilization and reaction products. The maximum concentration of
hemicellulosic sugars was achieved using autohydrolysis at 210 °C followed by posthydrolysis with 1% H2SO4 during 2 h. Data from autohydrolysis–posthydrolysis were compared with the results obtained at the optima conditions assayed
for prehydrolysis (3% H2SO4 at 130 °C during 15 min) based on previous works. Prehydrolysis extracted more hemicellulosic sugars from trimming vine shoots;
however, the protein content in the hydrolysates from autohydrolysis–posthydrolysis was higher. The harsher conditions assayed
during the autohydrolysis process and the higher content of protein after this treatment could induce Maillard reactions decreasing
consequently the concentration of hemicellulosic sugars in the hydrolysates. Therefore, despite the several advantages of
autohydrolysis (less equipment caused by the absence of mineral acid, less generation of neutralized sludges, and low cost
of reagents) the poor results obtained in this work with no detoxified hydrolysates (Q
P = 0.36 g/L h, Q
S = 0.79 g/L h, Y
P/S = 0.45 g/g, Y
P/Sth = 61.5 %) or charcoal-treated hydrolysates (Q
P = 0.76 g/L h, Q
S = 1.47 g/L h, Y
P/S = 0.52 g/g, Y
P/Sth = 71.5 %) suggest that prehydrolysis of trimming vine shoots with diluted H2SO4 is more attractive than autohydrolysis-posthydrolysis for obtaining lactic acid through fermentation of hemicellulosic sugars
with L. pentosus. Besides the higher hemicellulosic sugars concentration achieved when using the prehydrolysis technology, no detoxification
steps are required to produce efficiently lactic acid (Q
P = 1.14 g/L h; Q
S = 1.64 g/L h; Y
P/S = 0.70 g/g; Y
P/Sth = 92.6 %), even when vinification lees are used as nutrients (Q
P = 0.89 g/L h; Q
S = 1.54 g/L h; Y
P/S = 0.58 g/g; Y
P/Sth = 76.1 %). 相似文献
5.
Kwang Il Kim Woo Kyung Kim Deok Ki Seo In Sang Yoo Eun Ki Kim Hyon Hee Yoon 《Applied biochemistry and biotechnology》2003,107(1-3):637-647
Conversion of food wastes into lactic acid by simultaneous saccharification and fermentation (SSF) was investigated. The process
involves saccharification of the starch component in food wastes by a commercial amylolytic enzyme preparation (a mixture
of amyloglucosidase, α-amylase, and protease) and fermentation by Lactobacillus delbrueckii. The highest observed overall yield of lactic acid in the SSF was 91% of theoretical. Lactic acid concentration as high as
80 g/L was attainable in 48 h of the SSF. The optimum operating conditions for the maximum productivity were found to be 42°C
and pH 6.0. Without supplementation of nitrogen-containing nutrients, the lactic acid yield in the SSF decreased to 60%: 27
g/L of lactic acid from 60 g/L of food waste. The overall performance of the SSF, however, was not significantly affected
by the elimination of mineral supplements. 相似文献
6.
Actinobacillus succinogenes 130 Z was used to produce succinic acid from cheese whey in this study. At the presence of external CO2 supply, the effects of initial cheese whey concentration, pH, and inoculum size on the succinic acid production were studied.
The by-product formation during the fermentation process was also analyzed. The highest succinic acid yield of 0.57 was obtained
at initial cheese whey concentration of 50 g/L, while the highest succinic acid productivity of 0.58 g h−1 L−1 was obtained at initial cheese whey concentration of 100 g/L. Increase in pH and inoculum size caused higher succinic acid
yield and productivity. At the preferred fermentation condition of pH 6.8, inoculum size of 5% and initial cheese whey concentration
of 50 g/L, succinic acid yield of 0.57, and productivity of 0.44 g h−1 L−1 were obtained. Acetic acid and formic acid were the main by-products throughout the fermentation run of 48 h. It is feasible
to produce succinic acid using lactose from cheese whey as carbon resource by A. succinogenes 130 Z. 相似文献
7.
Effect of acetic acid and furfural on cellulase production of Trichoderma reesei RUT C30 总被引:4,自引:0,他引:4
Because of the high temperature applied in the steam pretreatment of lignocellulosic materials, different types of inhibiting
degradation products of saccharides and lignin, such as acetic acid and furfural, are formed. The main objective of the present
study was to examine the effect of acetic acid and furfural on the cellulase production of a filamentous fungus Trichoderma reesei RUT C30, which is known to be one of the best cellulase-producing strains. Mandels’s mineral medium, supplemented with steam-pretreated
willow as the carbon source at a concentration corresponding to 10 g/L of carbohydrate, was used. Four different concentration
levels of acetic acid (0–3.0 g/L) and furfural (0–1.2 g/L) were applied alone as well as in certain combinations. Two enzyme
activities, cellulase and β-glucosidase, were measured. The highest cellulase activity obtained after a 7-d incubation was
1.55 FPU/mL with 1.0 g/L of acetic acid and 0.8 g/L of furfural added to the medium. This was 17% higher than that obtained
without acetic acid and furfural. Furthermore, the results showed that acetic acid alone did not influence the cellulase activity
even at the highest concentration. However, β-glucosidase activity was increased with increasing acetic acid concentration.
Furfural proved to be an inhibiting agent causing a significant decrease in both cellulase and β-glucosidase production. 相似文献
8.
Hyang-Ok Kim Young-Jung Wee Jin-Nam Kim Jong-Sun Yun Hwa-Won Ryu 《Applied biochemistry and biotechnology》1996,131(1-3):694-704
The fermentative production of lactic acid from cheese whey and corn steep liquor (CSL) as cheap raw materials was investigated
by using Lactobacillus sp. RKY2 in order to develop a cost-effective fermentation medium. Lactic acid yields based on consumed lactose were obtained
at more than 0.98 g/g from the medium containing whey lactose. Lactic acid productivities and yields obtained from whey lactose
medium were slightly higher than those obtained from pure lactose medium. The lactic acid productivity gradually decreased
with increase in substrate concentration owing to substrate and product inhibitions. The fermentation efficiencies were improved
by the addition of more CSL to the medium. Moreover, through the cell-recycle repeated batch fermentation, lactic acid productivity
was maximized to 6.34 g/L/h, which was 6.2 times higher than that of the batch fermentation. 相似文献
9.
Ying Zhou José M. Domínguez Ningjun Cao Jianxin Du George T. Tsao 《Applied biochemistry and biotechnology》1999,78(1-3):401-407
The effect of nutrients on L(+)-lactic acid production from glucose was investigated using Rhizopus oryzae ATCC 523 11. From the shake-flask experiments, the optimal medium composition was defined for improved lactic-acid production.
In order to enhance lactic-acid production rate and product yield, controlled aeration in a bubble column was conducted under
optimal conditions. Results showed a maximum lactic-acid production rate of 2.58 g/L/h was obtained with an initial glucose
concentration of 94 g/L. Finallactic-acid concentration of 83 g/L was achieved after 32 h of fermentation with a weight of
0.88 glactic acid/g glucose consumed. 相似文献
10.
Hurok Oh Young-Jung Wee Jong-Sun Yun Hwa-Won Ryu 《Applied biochemistry and biotechnology》2003,107(1-3):603-613
The effect of various nitrogen sources on cell growth and lactic acid production was investigated. The most effective nitrogen
source was yeast extract; more yeast extract gave higher cell growth and lactic acid productivity. Yeast extract dosage and
cell growth were proportional up to a yeast extract concentration of 30 g/L, and lactic acid productivity was linearly correlated
up to a yeast extract dosage of 25 g/L. However, increasing the yeast extract content raises the total production cost of
lactic acid. Therefore, we attempted to find the optimum yeast extract dosage for a repeated-batch operation with cell recycling.
The results show that when using Enterococcus faecalis RKY1 only 26% of the yeast extract dosage for a conventional batch fermentation was sufficient to produce the same amount
of lactic acid, whereas the lactic acid concentration in the product stream (92–94 g/L) and lactic acid productivity (6.03–6.20
g/[L·h]) were similar to those of a batch operation. Furthermore, long-term stability was established. 相似文献
11.
Fábio C. Sampaio Paolo Torre Flávia M. Lopes Passos Célia Alencar de Moraes Patrizia Perego Attilio Converti 《Applied biochemistry and biotechnology》2007,136(2):165-181
To obtain in-depth information on the overall metabolic behavior of the new good xylitol producer Debaryomyces hansenii UFV-170, batch bioconversions were carried out using semisynthetic media with compositions simulating those of typical acidic
hemicellulose hydrolysates of sugarcane bagasse. For this purpose, we used media containing glucose (4.3–6.5 g/L), xylose
(60.1–92.1 g/L), or arabinose (5.9–9.2 g/L), or binary or ternary mixtures of them in either the presence or absence of typical
inhibitors of acidic hydrolysates, such as furfural (1.0–5.0 g/L), hydroxymethylfurfural (0.01–0.30 g/L), acetic acid (0.5–3.0
g/L), and vanillin (0.5–3.0 g/L). D. hansenii exhibited a good tolerance to high sugar concentrations as well as to the presence of inhibiting compounds in the fermentation
media. It was able to produce xylitol only from xylose, arabitol from arabinose, and no glucitol from glucose. Arabinose metabolization
was incomplete, while ethanol was mainly produced from glucose and, to a lesser less extent, from xylose and arabinose. The
results suggest potential application of this strain in xyloseto-xylitol bioconversion from complex xylose media from lignocellulosic
materials. 相似文献
12.
Luís C. Duarte Florbela Carvalheiro Joana Tadeu Francisco M. Gírio 《Applied biochemistry and biotechnology》2006,130(1-3):461-475
The combined effects of inhibitors present in lignocellulosic hydrolysates was studied using a multivariate statistical approach.
Acetic acid (0–6 g/L), formic acid (0–4.6 g/L) and hydroquinone (0–3 g/L) were tested as model inhibitors in synthetic media
containing a mixture of glucose, xylose, and arabinose simulating concentrated hemicellulosic hydrolysates. Inhibitors were
consumed sequentially (acetic acid, formic acid, and hydroquinone), alongside to the monosaccharides (glucose, xylose, and
arabinose). Xylitol was always the main metabolic product. Additionally, glycerol, ethanol, and arabitol were also obtained.
The inhibitory action of acetic acid on growth, on glucose consumption and on all product formation rates was found to be
significant (p≤0.05), as well as formic acid inhibition on xylose consumption and biomass production. Hydroquinone negatively affected biomass
productivity and yield, but it significantly increased xylose consumption and xylitol productivity. Hydroquinone interactions,
either with acetic or formic acid or with both, are also statistically signficant. Hydroquinone seems to partially lessen
the acetic acid and amplify formic acid effects. The results clearly indicate that the interaction effects play an important
role on the xylitol bioprocess. 相似文献
13.
M. J. T. Carrondo J. P. S. G. Crespo M. J. Moura 《Applied biochemistry and biotechnology》1988,17(1-3):295-312
The kinetics ofP. acidipropionici (ATCC25562), a xylose-utilizing rumen microorganism, was studied to assess its use for propionic acid production from wood
hydrolyzates.
Propionic acid has been shown to have a stronger inhibitory effect than acetic acid, with the undissociated acid form being
responsible for the majority of the inhibitory effect. Thus, in batch tests with pH controlled at 6.0, the propionic acid
concentration reaches 25 g/L and the acetic acid 7 g/L. Xylose uptake rate is dependent on the specific growth rate and glucose
concentration.
An immobilized cell columnar reactor at very high product yields (80%) proved adequate for propionic production. At cell concentrations
of 95 g/L with high product concentration, volumetric productivities of 2.7 g/L·h were obtained in ultrafiltration cell recycle
systems. 相似文献
14.
Radix Scrophulariae (Xuanshen) is one of the famous Chinese herbal medicines widely used to treat rheumatism, tussis, pharyngalgia, arthritis,
constipation, and conjunctival congestion. Harpagoside and cinnamic acid are the main bioactive components of Xuanshen. The
purpose of this study was to develop an HPLC–UV method for simultaneous determination of harpagoside and cinnamic acid in
rat plasma and investigate pharmacokinetic parameters of harpagoside and cinnamic acid after oral administration of Xuanshen
extract (760 mg kg−1). After addition of syringin as internal standard, the analytes were isolated from plasma by liquid–liquid extraction. Separation
was achieved on a Kromasil C18 column, and detection was by UV absorption at 272 nm. The described assay was validated in terms of linearity, accuracy,
precision, recovery, and limit of quantification according to the FDA validation guidelines. Calibration curves for both analytes
were linear with the coefficient of variation (r) for both was greater than 0.999. Accuracy for harpagoside and cinnamic acid ranged from 100.7–103.5% and 96.9–102.9%, respectively,
and precision for both analytes were less than 8.5%. The main pharmacokinetic parameters found for harpagoside and cinnamic
acid after oral infusion of Xuanshen extract were as follows: C
max 1488.7 ± 205.9 and 556.8 ± 94.2 ng mL−1, T
max 2.09 ± 0.31 and (1.48 ± 0.14 h, AUC0–24 10336.4 ± 1426.8 and 3653.1 ± 456.4 ng h mL−1, 11276.8 ± 1321.4 and 3704.5 ± 398.8 ng h mL−1, and t
1/2 4.9 ± 1.3 and 2.5 ± 0.9 h, respectively. These results indicated that the proposed method is simple, selective, and feasible
for pharmacokinetic study of Radix Scrophulariae extract in rats.
Figure Radix Scrophulariae 相似文献
15.
Aspergillus niger ATCC 9142 mycelium was entrapped in calcium alginate beads and employed in an air-lift completely stirred reactor for continuous
production of citric acid. Maximum yield obtained from 10% (w/v) sucrose was 12 g dm-3 with about 40% fermentation efficiency. Maximum rate of production 70 mg g-1 h-1 was about five times that obtained in classical batch fermentation. 相似文献
16.
Xylitol production by Debaryomyces hansenii NRRL Y-7426 was performed on synthetic medium varying the initial xylose concentration between 50 and 300 g/L. The experimental
results of these tests were used to investigate the effect of substrate level on xylose consumption by this yeast. Satisfactory
values of product yield on substrate (0.74–0.83 g/g) as well as volumetric productivity (0.481–0.694 g/L·h) were obtained
over a wide range of xylose levels (90–200 g/L), while a worsening of kinetic parameters took place at higher concentration,
likely due to a substrate inhibition phenomenon. The metabolic behavior of D. hansenii was studied, under these conditions, through a carbon material balance to estimate the fractions of xylose consumed by the
cell for different activities (xylitol production, biomass growth, and respiration) during the lag, exponential, and stationary
phases. 相似文献
17.
Hugh G. Lawford Joyce D. Rousseau Ali Mohagheghi James D. McMillan 《Applied biochemistry and biotechnology》1999,77(1-3):191-204
Long-term (149 d) continuous fermentation was used to adapt a xylose-fermenting recombinant Zymomonas mobilis, strain 39676:pZB 4L, to conditioned (overlimed) dilute-acid yellow poplar hemicellulose hydrolyzate (“prehydrolyzate”).
An “adapted” variant was isolated from a chemostat operating at a dilution rate of 0.03/h with a 50% (v/v) prehydrolyzate,
corn steep liquor, and sugar-supplemented medium, at pH 5.75. The level of xylose and glucose in the medium was kept constant
at 4% (w/v) and 0.8% (w/v), respectively. These sugar concentrations reflect the composition of the undiluted hardwood prehydrolyzate.
The level of conditioned hardwood prehydrolyzate added to the medium was increased in 5% increments startingata level of 10%.
At the upper level of 50% prehydrolyzate, the acetic-acid concentration was about 0.75% (w/v). The adapted variant exhibited
improved xylose-fermentation performance in a pure-sugar, synthetic hardwood prehydrolyzate medium containing 4% xylose (w/v),
0.8% (w/v) glucose, and acetic acid in the range 0.4–1.0% (w/v). The ethanol yield was 0.48–0.50 g/g; equivalent to a sugar-to-ethanol
conversion efficiency of 94–96% of theoretical maximum. The maximum growth yield and maintenance energy coefficients were
0.033 g dry cell mass (DCM)/g sugars and 0.41 g sugars/g DCM/h, respectively. The results confirm that long-term continuous
adaptation is a useful technique for effecting strain improvement with respect to the fermentation of recalcitrant feedstocks. 相似文献
18.
Succinic acid was produced efficiently from fumaric acid by a recombinantE. coli strain DH5αt/pGC1002 containing multicopy fumarate reductase genes. The effects of initial fumaric acid and glucose concentration
on the production of succinic acid were investigated. Succinic acid reached 41 to over 60 g/L in 48.5 h starting with 50 to
64 g/L fumaric acid. Significant substrate inhibition was observed at initial fumaric acid concentration of 90 g/L. L-Malic
acid became the major fermentation product under these conditions. Provision of glucose (5-30 g/L) to the fermentation medium
stimulated the initial succinic acid production rate over two folds. 相似文献
19.
Continuous production of L-aspartic acid 总被引:2,自引:0,他引:2
For the continuous production ofl-aspartic acid from fumaric acid and ammonia by the action of aspartase, the enzyme extracted fromEscherichia coli orE. coli cells having high aspartase activity were immobilized by various methods.
In 1973 we succeeded in the industrial production ofl-aspartic acid usingE. coli cells immobilized with polyacrylamide gel.
For the improvement of this process, we developed a novel technique using κ-carrageenan as the immobilizing matrix forE. coli cells. Further, EAPc-7 strain, having higher aspartase activity, was contracted from the parentE. coli by continuous cultivation with a definite medium. The aspartase activity was about seven times higher than that of the parent
cells. In 1982 we changed from the conventional method to the improved method, using EAPc-7 strain immobilized with κ-carrageenan. 相似文献
20.
Simultaneous production of citric acid and erythritol from crude glycerol by Yarrowia lipolytica Wratislavia K1 总被引:2,自引:0,他引:2
This study shows a possible microbial process for utilization of crude glycerol generated by the biodiesel industry for citric
acid and erythritol production. Simultaneous production of citric acid and erythritol under nitrogen-limited conditions with
glycerol as the carbon source was achieved with an acetate negative mutant of Y. lipolytica Wratislavia K1 in fed-batch cultivations. The effect of the initial glycerol concentration (from 30–180 g dm−3) on the citrate and erythritol production was investigated. As a result of the experiments, maximum citric acid production
(110 g dm−3) and a very high amount of erythritol (81 g dm−3) were determined after 168 h of fed-batch cultivation with the initial glycerol concentration of 150 g dm−3 and the total glycerol concentration of 250 g dm−3. In addition, the citric acid to isocitric acid ratio of the products from this strain was 35.5:1.
Presented at the 34th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 21–25 May
2007. 相似文献