共查询到20条相似文献,搜索用时 31 毫秒
1.
Thaddeus C. Ezeji Marisa Groberg Nasib Qureshi Hans P. Blaschek 《Applied biochemistry and biotechnology》2003,106(1-3):375-382
Acetone, butanol, ethanol (ABE, or solvents) were produced from starch-based packing peanuts in batch and continuous reactors.
In a batch reactor, 18.9 g/L of total ABE was produced from 80 g/L packing peanuts in 110 h of fermentation. The initial and
final starch concentrations were 69.6 and 11.1 g/L, respectively. In this fermentation, ABE yield and productivity of 0.32
and 0.17 g/(L·h) were obtained, respectively. Compared to the batch fermentation, continuous fermentation of 40 g/L of starch-based
packing peanuts in P2 medium resulted in a maximum solvent production of 8.4 g/L at a dilution rate of 0.033 h−1. This resulted in a productivity of 0.27 g/(L·h). However, the reactor was not stable and fermentation deteriorated with
time. Continuous fermentation of 35 g/L of starch solution resulted in a similar performance. These studies were performed
in a vertical column reactor using Clostridium beijerinckii BA101 and P2 medium. It is anticipated that prolonged exposure of culture to acrylamide, which is formed during boiling/autoclaving
of starch, affects the fermentation negatively. 相似文献
2.
Butanol production using Clostridium beijerinckii BA101 hyper-butanol producing mutant strain and recovery by pervaporation 总被引:1,自引:0,他引:1
Clostridium beijerinckii BA101 (mutant strain) and C. beijerinckii 8052 (wild type) were compared for substrate and butanol inhibition. The wild-type strain is more strongly inhibited by added
butanol than is the mutant strain. Acetone and butanol were removed from a fed-batch reactor inoculated with C. beijcrinckii BA101 by pervaporation using a silicone membrane. In the batch reactor, C. beijerinckii BA101 produced 25.3 g/L of total solvents, whereas in the fermentation-recovery experiment it produced 165.1 g/L of total
solvents. Solvent productivity increased from 0.35 (batch reactor) to 0.98 g/L·h (fed-batch reactor). The fed-batch reactor
wasfed with 500 g/L of glucose-based P2 medium. Acetone selectivities ranged from 2 to 10 whereas butanol selectivities ranged
from 7 to 19. Total flux varied from 26 to 31 g/m2·h. 相似文献
3.
Wei-Cho Huang David E. Ramey Shang-Tian Yang 《Applied biochemistry and biotechnology》2004,115(1-3):887-898
We explored the influence of dilution rate and pH in continuous cultures of Clostridium acetobutylicum. A 200-mL fibrous bed bioreactor was used to produce high cell density and butyrate concentrations at pH 5.4 and 35°C. By
feeding glucose and butyrate as a cosubstrate, the fermentation was maintained in the solventogenesis phase, and the optimal
butanol productivity of 4.6g/(L h) and a yield of 0.42 g/g were obtained at a dilution rate of 0.9h−1 and pH 4.3. Compared to the conventional acetone-butanol-ethanol fermentation, the new fermentation process greatly improved
butanol yield, making butanol production from corn an attractive alternative to ethanol fermentation. 相似文献
4.
Nasib Qureshi Patrick Karcher Michael Cotta Hans P. Blaschek 《Applied biochemistry and biotechnology》2004,114(1-3):713-721
Corn steep liquor (CSL), a byproduct of the corn wet-milling process, was used in an immobilized cell continuous biofilm reactor
to replace the expensive P2 medium ingredients. The use of CSL resulted in the production of 6.29 g/L of total acetone-butanol-ethanol
(ABE) as compared with 6.86 g/L in a control experiment. These studies were performed at a dilution rate of 0.32 h−1. The productivities in the control and CSL experiment were 2.19 and 2.01 g/(L·h), respectively. Although the use of CSL resulted
in a 10% decrease in productivity, it is viewed that its application would be economical compared to P2 medium. Hence, CSL
may be used to replace the P2 medium. It was also demonstrated that inclusion of butyrate into the feed was beneficial to
the butanol fermentation. A control experiment produced 4.77 g/L of total ABE, and the experiment with supplemented sodium
butyrate produced 5.70 g/L of total ABE. The butanol concentration increased from 3.14 to 4.04 g/L. Inclusion of acetate in
the feed medium of the immobilized cell biofilm reactor was not found to be beneficial for the ABE fermentation, as reported
for the batch ABE fermentation.
Names are necessary to report factually on available data. However, the USDA neither guarantees nor warrants the standard
of the product, and the use of the names by USDA implies no approval of the product to the exclusion of others that may also
be suitable. 相似文献
5.
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
6.
The continuous cultivation of immobilized Saccharomyces cerevisiae CBS 8066 on dilute-acid hydrolysates of forest residuals was investigated. The yeast cells were immobilized in 2–4% Ca-alginate
beads. The 2% beads were not stable. However, the 3 and 4% beads were stable for at least 3 wk when an extra resource of calcium
ions was available in the medium. The continuous cultivation of a dilute-acid hydrolysate by the immobilized cells at dilution
rates of 0.3, 0.5, and 0.6 h−1 resulted in 86, 83, and 79% sugar consumption, respectively, and an ethanol yield between 0.45 and 0.48 g/g. The hydrolysate
was fermentable at a dilution rate of 0.1 h−1 in a free-cell system but washed out at a dilution rate of 0.2 h−1. The continuous cultivation of a more inhibiting hydrolysate was not successful by either free- or immobilized-cell systems
even at a low dilution rate of 0.07 h−1. However, when the hydrolysate was overlimed, it was fermentable by the immobilized cells at a dilution rate of 0.2 h−1. 相似文献
7.
Triantafyllos Roukas 《Applied biochemistry and biotechnology》1996,59(3):299-307
The continuous production of ethanol from nonsterilized carob pod extract by immobilizedSaccharomyces cerevisiae on mineral kissiris using one- and two-reactor systems has been investigated. A maximum ethanol productivity of 9.6 g/L/h
was obtained at an initial sugar concentration of 200 g/L and D = 0.4 h-1 with 68% of theoretical yield and 34% of sugar utilization using the one-reactor system. AtS
0 = 200 g/L, D = 0.05 h-1, 83% of theoretical yield, and 64% of sugar utilization, an ethanol productivity of 2.6 g/L/h was achieved. In the tworeactor
system, a maximum ethanol productivity of 11.4 g/L/h was obtained at S0 = 200 g/L and D = 0.4 h-1 with 68.5% of theoretical yield and 41.5% of sugar utilization. The two-reactor system was operated at a constant dilution
rate of 0.3 h-1 for 60 d without loss of the original immobilized yeast activity. In this case, the average ethanol productivity, ethanol
yield (% of theoretical), and sugar utilization were 10.7 g/L/h, 71.5%, and 48%, respectively. 相似文献
8.
Heizir F. de Castro Samuel C. Oliveira Sandra A. Furlan 《Applied biochemistry and biotechnology》2003,107(1-3):547-555
A new approach for the utilization of hemicellulosic hydrolysate from sugarcane bagasse is described. This approach consists
of using the hydrolysate to dilute the conventional feedstock (sugarcane juice) to the usual sugar concentration (150 g/L)
employed for the industrial production of ethanol. The resulting sugar mixture was used as the substrate to evaluate the performance
of a continuous reactor incorporating a cell recycle module, operated at several dilution rates. An induced flocculent pentose-fermenting
yeast strain was used for this bioconversion. Under the conditions used, the reactor performance was satisfactory at substrate
feed rates of 30 g/(L·h) or less, corresponding to an ethanol productivity of about 11.0 g/(L·h) and an overall sugar conversion
>95%. These results show real advantages over the existing alternatives for a better exploitation of surplus bagasse to increase
industrial alcohol production. 相似文献
9.
Campos Edhilvia J. Qureshi Nasib Blaschek Hans P. 《Applied biochemistry and biotechnology》2002,98(1-9):553-561
In this article we report on acetone butanol ethanol (ABE) fermentation characteristics of degermed corn when using Clostridium beijerinckii BA101. Recent economic studies suggested that recovery of germ from corn and hence corn oil would help to make the ABE fermentation
process more economical. C. beijerinckii BA101 ferments corn mash efficiently to produce ABE under appropriate nutritional and environmental conditions. Corn mash
contains germ/corn oil that is, possibly, ancillary to the production of butanol during the ABE fermentation process. Since
the presence of corn oil is not a critical factor in solvent fermentation, it can be removed and this will allow for byproduct
credit. Batch fermentation of degermed corn resulted in 8.93 g/L of total ABE production as compared with 24.80 g/L of total
ABE when supplemented with P2 medium nutrients. During the course of the germ separation process, corn steeping is required
prior to grinding and removing the germ. It is likely that some nutrients from the corn are leached out during the steeping
process. This may reduce the rate of fermentation and impact the final concentration of butanol/ABE that can be achieved.
Fermentation of degermed corn with corn steep liquor resulted in the production of 19.28 g/L of ABE. 相似文献
10.
Kazunori Uematsu Douglas Fong Dewey D. Y. Ryu 《Applied biochemistry and biotechnology》1988,19(2):177-188
The continuous wine fermentation process, which employs a newly designed tapered column type bioreactor and immobilized yeast cells (Montrachet 522), was studied and its fermentation performance was compared with batch and suspended cell continuous wine fermentation systems. It was found that a stable continuous culture fermentation process could be maintained for a period of 2–3 mo when the new bioreactor system packed with immobilized yeast cells was employed. The new bioreactor containing immobilized yeast cells performed significantly better than the suspended cell culture system or batch culture. The effluent wine from the continuous fermentor system contained 7.1% (v/v) ethanol and 0.18% (w/v) residual sugar at 0.01 h-1 dilution rate. The new continuous bioreactor system also gave 17–34 times higher maximum ethanol productivity compared to the conventional batch wine fermentation. At a low dilution rate, 0.01-1, as high as 92% sugar to ethanol yield was achieved. Based on the results obtained from this study, the possibility of developing a continuous wine cooler fermentation process was demonstrated. A two-stage continuous wine fermentation system may be designed and operated. The grape juice can be fed into the first-stage that is operated at about 0.2 h-1 dilution rate and the effluent from the first-stage is fed into the second-stage continuous fermentor operated at about 0.01 h-1 dilution rate. By doing so, a wine cooler can be produced continuously and efficiently, by employing the newly designed tapered column type bioreactor charged with the immobilized yeast cells. 相似文献
11.
Gi-Wook Choi Hyun-Woo Kang Se-Kwon Moon Bong-Woo Chung 《Applied biochemistry and biotechnology》2010,160(5):1517-1527
In this study, a fermentor consisting of four linked stirred towers that can be used for simultaneous saccharification and
fermentation (SSF) and for the accumulation of cell mass was applied to the continuous production of ethanol using cassava
as the starchy material. For the continuous process with SSF, the pretreated cassava liquor and saccharification enzyme at
total sugar concentrations of 175 g/L and 195 g/L were continuously fed to the fermentor with dilution rates of 0.014, 0.021,
0.031, 0.042, and 0.05 h−1. Considering the maximum saccharification time, the highest volumetric productivity and ethanol yield were observed at a
dilution rate of 0.042 h−1. At dilution rates in the range of 0.014 h−1 to 0.042 h−1, high production rates were observed, and the yeast in the first to fourth fermentor showed long-term stability for 2 months
with good performance. Under the optimal culture conditions with a feed sugar concentration of 195 g/L and dilution rate of
0.042 h−1, the ethanol volumetric productivity and ethanol yield were 3.58 g/L∙h and 86.2%, respectively. The cell concentrations in
the first to fourth stirred tower fermentors were 74.3, 71.5, 71.2, and 70.1 g dry cell/L, respectively. The self-flocculating
yeast, Saccharomyces cerevisiae CHFY0321, developed by our group showed excellent fermentation results under continuous ethanol production. 相似文献
12.
The exponential cells ofBacillus cereus immobilized in calcium alginate and spun into microcylindrical particles were used in a fluidized-bed reactor for continuous
synthesis of thermostable α-amylase. The reactor was operated over a period of 30 d with a dilution rate of 0.33 h-1, producing 1000–1200 U/mL of enzyme. The productivity of the reactor was in the range of 330–396 kU/h. A 20-fold increase
in the productivity with respect to batch fermentation with free cells was attained. 相似文献
13.
Lawford Hugh G. Rousseau Joyce D. Mohagheghi Ali McMillan James D. 《Applied biochemistry and biotechnology》2000,84(1-9):295-310
This study examined the continuous cofermentation performance characteristics of a dilute-acid “prehydrolysate-adapted” recombinant
Zymomonas 39676:pZB4L and builds on the pH-stat batch fermentations with this recombinant that we reported on last year. Substitution
of yeast extract by 1% (w/v) corn steep liquor (CSL) (50% solids) and Mg (2 mM) did not alter the coferm entation performance.
Using declared assumptions, the cost of using CSL and Mg was estimated to be 12.5c/gal of ethanol with a possibility of 50%
cost reduction using fourfold less CSL with 0.1% diammonium phosphate. Because of competition for a common sugar transporter
that exhibits a higher affinity for glucose, utilization of glucose was complete whereas xylose was always present in the
chemostat effluent. The ethanol yield, based on sugar used, was 94% of theoretical maximum. Altering the sugar ratio of the
synthetic dilute acid hardwood prehydrolysate did not appear to significantly change the pattern of xylose utilization. Using
a criterion of 80% sugar utilization for determining the maximum dilution rate (D
max), changing the composition of the feed from 4% xylose to 3%, and simultaneously increasing the glucose from 0.8 to 1.8% shifted
D
max from 0.07 to 0.08/h. With equal amounts of both sugars (2.5%), D
max was 0.07/h. By comparison to a similar investigation with rec Zm CP4:pZB5 with a 4% equal mixture of xylose and glucose,
we observed that at pH 5.0, the D
max was 0.064/h and shifted to 0.084/h at pH 5.75. At a level of 0.4% (w/v) acetic acid in the CSL-based medium with 3% xylose
and 1.8% glucose at pH 5.75, the D
max for the adapted recombinant shifted from 0.08 to 0.048/h, and the corresponding maximum volumetric ethanol productivity decreased
45%, from 1.52 to 0.84 g/(L·h). Under these conditions of continuous culture, linear regression of a Pirt plot of the specific
rate of sugar utilization vs D showed that 4 g/L of acetic acid did not affect the maximum growth yield (0.030 g dry cell mass/g sugar), but did increase
the maintenance coefficient twofold, from 0.46 to 1.0 g of sugar/(g of cell·h). 相似文献
14.
H. Moon S. W. Kim J. Lee S. K. Rhee E. S. Choi H. A. Kang I. H. Kim S. I. Hong 《Applied biochemistry and biotechnology》2003,111(2):65-79
As a novel feeding strategy for aptomizing human epidermal growth factor (hEGF) production with a recombinant Hansenula polymorpha DL-1 using the methanol oxidase (MOX) promoter in H. polymorpha DL-1, independent exponential feeding of two substrates was used. A simple kinetic model considering the cell growth on two
substrates was established and used to calculate the respective feeding rates of glycerol and methanol. In the fedbatch culture
with methanol-only feeding, the optimal set point of specific growth rate on methanol was found to be 0.10 h−1. When the fed-batch cultures were conducted by the independent feeding of glycerol and methanol, the actual specific growth
rate on glycerol and methanol was slightly lower than the set point of specific growth rate. By the uncoupled feeding of glycerol
and methanol the volumetric productivity of hEGF increased from 6.4 to 8.0 mg/(L·h), compared with methanol-only feeding. 相似文献
15.
Gimenes Maria Antonieta P. Carlos Luiz Cláudio S. Faria Luís F. F. Pereira Nei 《Applied biochemistry and biotechnology》2002,98(1-9):1049-1059
The global oxygen uptake rate (OUR) and specific oxygen uptake rates (SOUR) were determined for different values of the volumetric
oxygen mass transfer coefficient (15, 43, and 108 h−1), and for varying initial xylose concentrations (50, 100, 150, and 200 g/L) in shaking flasks. The initial cell concentration
was 4.0 g/L, and there was only significant growth in the fermentation with the highest oxygen availability. In this condition,
OUR increased proportionally to cell growth, reaching maximum values from 2.1 to 2.5 g of O2/(L·h) in the stationary phase when the initial substrate concentration was raised from 50 to 200 g/L, respectively. SOUR
showed different behavior, growing to a maximum value coinciding with the beginning of the exponential growth phase, after
which point it decreased. The maximum SOUR values varied from 265 to 370 mg of O2/(g of cell·h), indicating the interdependence of this parameter and the substrate concentration. Although the volumetric
productivity dropped slightly from 1.55 to 1.18 g of xylitol/(L·h), the strain producing capacity (γ
P/X
) rose from 9 to 20.6 g/g when the initial substrate concentration was increased from 50 to 200 g/L. As for the xylitol yield
over xylose consumed (γ
P/S
), there was no significant variation, resulting in a mean value of 0.76 g/g. The results are of interest in establishing
a strategy for controlling the dynamic oxygen supply to maximize volumetric productivity. 相似文献
16.
Spores ofClostridium acetobutylicum were immobilized in calcium alginate. An active gel preparation was obtained after outgrowth of the spores to vegetative
cells within the gel matrix. A 100 mL column containing the immobilized cells was used for continuous production. At steady-state
conditions the productivity of butanol was 67 g/L reactor volume/day. 相似文献
17.
PVA-Hydrogel Entrapped <Emphasis Type="Italic">Candida Guilliermondii</Emphasis> for Xylitol Production from Sugarcane Hemicellulose Hydrolysate 总被引:1,自引:0,他引:1
da Cunha MA Converti A Santos JC Ferreira ST da Silva SS 《Applied biochemistry and biotechnology》2009,157(3):527-537
Viable cells of Candida guilliermondii were immobilized by inclusion into polyvinyl alcohol (PVA) hydrogel using the freezing–thawing method. Entrapment experiments
were planned according to a 23 full factorial design, using the PVA concentration (80, 100, and 120 g L−1), the freezing temperature (−10, −15, and −20 °C), and the number of freezing-thawing cycles (one, three, and five) as the
independent variables, integrated with three additional tests to estimate the errors. The effectiveness of the immobilization
procedure was checked in Erlenmeyer flasks as the pellet capability to catalyze the xylose-to-xylitol bioconversion of a medium
based on sugarcane bagasse hemicellulosic hydrolysate. To this purpose, the yield of xylitol on consumed xylose, xylitol volumetric
productivity, and cell retention yield were selected as the response variables. Cell pellets were then used to perform the
same bioconversion in a stirred tank reactor operated at 400 rpm, 30 °C, and 1.04 vvm air flowrate. At the end of fermentation,
a maximum xylitol concentration of 28.7 g L−1, a xylitol yield on consumed xylose of 0.49 g g−1 and a xylitol volumetric productivity of 0.24 g L−1 h−1 were obtained. 相似文献
18.
Faria Luis F. Figueiredo Gimenes Maria Antonieta P. Nobrega Ronaldo Pereira Nei 《Applied biochemistry and biotechnology》2002,98(1-9):449-458
Oxygen availability is the most important environmental parameter in the production of xylitol by yeasts, directly affecting
yields and volumetric productivity. This work evaluated the cell behavior in fermentations carried out with different dissolved
oxygen concentrations (0.5–30.0% of saturation), as well as a limited oxygen restriction (0% of saturation), at several oxygen
volumetric transfer coefficients (12 ≤ k
L
a ≤ 70 h−1). These experiments allowed us to establish the specific oxygen uptake rate limits to ensure high yields and volumetric productivity.
When oxygen availability was limited, the specific oxygen uptake rate values were between 12 and 26 mg of O2/of g cell·h, resulting in a yield of 0.71 g of xylitol/xylose consumed, and 0.85 g/[L·h] for the volumetric productivity.
According to the results, the effective control of the specific oxygen uptake rate makes it possible to establish complete
control over this fermentative process, for both cell growth and xylitol production. 相似文献
19.
The kinetics of continuous citric acid (CA) fermentation, using two acetate-negative mutants of Yarrowia lipolytica (Wratislavia AWG7 and Wratislavia 1.31) with long-term cell recycle, were investigated at a dilution rate (D) of 0.011 h−1. The capacity of the mutants to produce CA from raw glycerol under steady state conditions was compared. The process involving
the Wratislavia AWG7 strain showed that this strain was a better producer of CA than the Wratislavia 1.31 strain in this regime.
In steady state, the concentration of CA in the effluent was constant and amounted to 116 g dm−3. This corresponded to a volumetric CA production rate of 1.3 g dm−3 h−1. A stable high-level production of CA was maintained for over 400 h of operation. The Wratislavia AWG7 strain employed remained
highly stable throughout the experiment and demonstrated good viability, high genetic and phenotypic stability over the long-term
continuous fermentation process. 相似文献
20.
Hou-Rui Z Xiang-Xiang Q Silva SS Sarrouh BF Ai-Hua C Yu-Heng Z Ke J Qiu X 《Applied biochemistry and biotechnology》2009,152(2):199-212
In this paper, two new strians, Issatchenkia occidentalis (Lj-3, CCTCC M 2006097) and Issatchenkia orienalis (S-7, CCTCC M 2006098), isolated from different environments on solid media, were used in the detoxification process of the
hemicellulosic hydrolysate of sugarcane bagasse. High-pressure liquid chromatography elution curve of UV-absorption compounds
represented by acetic acid, furfural, and guaiacol (toxic compounds found in the hemicellulosic hydrolysate) showed that several
chromatographic peaks were evidently diminished for the case of detoxified hydrolysate with isolate strains compared to the
high peaks resulted for no detoxified hydrolysate. It was clear that these inhibitors were degraded by the two new isolates
during their cultivation process. Fermentation results for the biodetoxified hydrolysate showed an increase in xylitol productivity
(Q
p) by 1.97 and 1.95 times (2.03 and 2.01 g l−1 h−1) and in xylitol yield (Y
p) by 1.72 and 1.65 times (0.93 and 0.89 g xylitol per gram xylose) for hydrolysate treated with S-7 and Lj-3, respectively,
in comparison with no detoxified hydrolysate (1.03 g l−1 h−1 and 0.54 g xylitol per gram xylose). This present work demonstrated the importance of Issatchenkia yeast in providing an effective biological detoxification approach to remove inhibitors and improve hydrolysate fermentability,
leading to a high xylitol productivity and yield. 相似文献