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1.
The scale-up strategy for acarbose fermentation by Actinoplanes sp. A56 was explored in this paper. The results obtained in shake-flask cultivation demonstrated that the ratio of maltose
and glucose had significant effects on the biosynthesis of acarbose, and the feeding medium containing 3:1 (mass ratio) of
maltose and glucose was favorable for acarbose production. Then the correlation of the carbon source concentration with acarbose
production was further investigated in 100-l fermenter, and the results showed that 7.5–8.0 g of total sugar/100 ml and 4.0–4.5 g
of reducing sugar/100 ml were optimal for acarbose production. Based on the results in 100-l fermenter, an effective and simplified
scale-up strategy was successfully established for acarbose fermentation in a 30-m3 fermenter, by using total sugar and reducing sugar as the scale-up parameter. As a result, 4,327 mg of acarbose/l was obtained
at 168 h of fermentation. 相似文献
2.
《Process Biochemistry》2014,49(12):2044-2048
Production of pediocin SM-1 by Pediococcus pentosaceus Mees 1934 was investigated in semi-aerobic, pH-controlled, batch and fed-batch fermentations using a complex medium containing sucrose as the main source of carbon. The effects of sucrose concentration were studied in fed-batch fermentations in which a sucrose solution was added at stable feeding rates (5, 7, 9 and 10 g/l/h). The results showed that pediocin is produced as a product of the primary metabolism and its titer could be greatly improved by adjusting the sucrose feeding rate in fed-batch fermentation. The maximum titer of pediocin of 145 AU/ml was obtained in the fed-batch culture with 7 g/l/h feeding rate and that was 119% higher compared to the titer obtained in batch culture. Higher feeding rates (9 and 10 g/l/h) resulted in decreased pediocin yields while biomass levels appeared to be rather unaffected. The specific rate of pediocin formation was also sensitive to sucrose concentration levels. A mathematical model developed on the basis of well-known rate equations for batch and fed-batch cultures and growth associated production, described successfully cell growth, sucrose assimilation, lactate production and pediocin production in fed-batch culture. 相似文献
3.
Kim HM Paik SY Ra KS Koo KB Yun JW Choi JW 《Journal of microbiology (Seoul, Korea)》2006,44(2):233-242
The objectives of this study were to optimize submerged culture conditions of a new fungal isolate, Ganorderma resinaceum, and to enhance the production of bioactive mycelial biomass and exopolysaccharides (EPS) by fed-batch culture. The maximum mycelial growth and EPS production in batch culture were achieved in a medium containing 10 g/l glucose, 8 g/l soy peptone, and 5 mM MnCl(2) at an initial pH 6.0 and temperature 31 degrees C. After optimization of culture medium and environmental conditions in batch cultures, a fed-batch culture strategy was employed to enhance production of mycelial biomass and EPS. Five different EPS with molecular weights ranging from 53,000 to 5,257,000 g/mole were obtained from either top or bottom fractions of ethanol precipitate of culture filtrate. A fed-batch culture of G. resinaceum led to enhanced production of both mycelial biomass and EPS. The maximum concentrations of mycelial biomass (42.2 g/l) and EPS (4.6 g/l) were obtained when 50 g/l of glucose was fed at day 6 into an initial 10 g/l of glucose medium. It may be worth attempting with other mushroom fermentation processes for enhanced production of mushroom polysaccharides, particularly those with industrial potential. 相似文献
4.
Enhancement of 5-aminolevulinate production with recombinant Escherichia coli using batch and fed-batch culture system 总被引:1,自引:0,他引:1
5-Aminolevulinate (ALA) production with recombinant Escherichia coli Rosetta (DE3)/pET28a(+)-hemA was studied. In batch fermentation, the addition of glucose and glycine was effective to improve ALA production. Then the fed-batch fermentation was conducted with continuous feeding of precursors. When the concentrations of succinic acid and glycine were 7.0 g/l and 4.0 g/l, respectively, in the feeding, the ALA yield reached 4.1g/l. But the molar yield (ALA/glycine) was decreased in the fed-batch fermentation compared to batch fermentation. And it was found that the pH control during fed-batch cultivation was very important for the cell growth and ALA production. A two-stage pH value controlling strategy was suggested, in which, the pH value in the first 6h was regulated at pH 5.9, after then at pH 6.2, and the ALA yield was as high as 6.6g/l via fed-batch fermentation. 相似文献
5.
The recombinant E. coli Delta6 mutant (galR, glpK, gldA, IdhA, lacI, tpiA) was used to produce 1,3-propanediol (PD) from glucose. The 1,3-PD production increased with feedback control of the glucose concentration using fed-batch fermentation. The maximum 1,3-PD concentration produced was 43 g/l after 60 h of fermentation. Glycerol production was minimized when controlling the glucose concentration at less than 1 g/l. The expression levels of seven enzymes related to the 1,3-PD production metabolism were compared during the cell growth phase and 1,3-PD production phase, and their expression levels all increased during 1,3-PD production, with the exception of alcohol dehydrogenase. 相似文献
6.
Chang HN Kim NJ Kang J Jeong CM Choi JD Fei Q Kim BJ Kwon S Lee SY Kim J 《Bioprocess and biosystems engineering》2011,34(4):419-431
We carried out the first simulation on multi-stage continuous high cell density culture (MSC-HCDC) to show that the MSC-HCDC
can achieve batch/fed-batch product titer with much higher productivity to the fed-batch productivity using published fermentation
kinetics of lactic acid, penicillin and ethanol. The system under consideration consists of n-serially connected continuous stirred-tank reactors (CSTRs) with either hollow fiber cell recycling or cell immobilization
for high cell-density culture. In each CSTR substrate supply and product removal are possible. Penicillin production is severely
limited by glucose metabolite repression that requires multi-CSTR glucose feeding. An 8-stage C-HCDC lactic acid fermentation
resulted in 212.9 g/L of titer and 10.6 g/L/h of productivity, corresponding to 101 and 429% of the comparable lactic acid
fed-batch, respectively. The penicillin production model predicted 149% (0.085 g/L/h) of productivity in 8-stage C-HCDC with
40 g/L of cell density and 289% of productivity (0.165 g/L/h) in 7-stage C-HCDC with 60 g/L of cell density compared with
referring batch cultivations. A 2-stage C-HCDC ethanol experimental run showed 107% titer and 257% productivity of the batch
system having 88.8 g/L of titer and 3.7 g/L/h of productivity. MSC-HCDC can give much higher productivity than batch/fed-batch
system, and yield a several percentage higher titer as well. The productivity ratio of MSC-HCDC over batch/fed-batch system
is given as a multiplication of system dilution rate of MSC-HCDC and cycle time of batch/fed-batch system. We suggest MSC-HCDC
as a new production platform for various fermentation products including monoclonal antibody. 相似文献
7.
Li Hua Jin Kyuhyuk Kwun Jung-heon Lee 《World journal of microbiology & biotechnology》2008,24(9):1657-1662
A fed-batch fermentation process for the production of organophosphorus hydrolase (OPH) (EC 3.1.8.1) by E. coli pET812 was developed in this research. With batch fermentation, the maximum OPH concentrations attained by batch fermentation
were as low as 4 × 105 U/l because cell growth and OPH production were inhibited by a high initial concentration of glucose. To develop a fed-batch
fermentation process for obtaining higher concentrations of OPH, highly concentrated glucose solution (500 g/l) was added
intermittently or continuously to increase the carbon source concentration. Eventually, 3.2 × 106 U/l of OPH was produced with fed-batch fermentation in 24 h. This was eight times higher than the yield with conventional
batch fermentation. A total concentration of 399–441 mg of OPH was produced/l, which was four times higher than that reported
when using E. coli. Nearly half (44%) of the produced OPH was secreted into the culture solution. 相似文献
8.
Yongqian Fu Xiaolong Sun Huayue Zhu Ru Jiang Xi Luo Longfei Yin 《World journal of microbiology & biotechnology》2018,34(6):74
In previous work, we proposed a novel modified one-step fermentation fed-batch strategy to efficiently generate l-lactic acid (l-LA) using Rhizopus oryzae. In this study, to further enhance efficiency of l-LA production through one-step fermentation in fed-batch cultures, we systematically investigated the initial peptone- and glucose-feeding approaches, including different initial peptone and glucose concentrations and maintained residual glucose levels. Based on the results of this study, culturing R. oryzae with initial peptone and glucose concentrations of 3.0 and 50.0 g/l, respectively, using a fed-batch strategy is an effective approach of producing l-LA through one-step fermentation. Changing the residual glucose had no obvious effect on the generation of l-LA. We determined the maximum LA production and productivity to be 162 g/l and 6.23 g/(l·h), respectively, during the acid production stage. Compared to our previous work, there was almost no change in l-LA production or yield; however, the productivity of l-LA increased by 14.3%. 相似文献
9.
10.
Mugihito Oshiro Katsuhiro Hanada Yukihiro Tashiro Kenji Sonomoto 《Applied microbiology and biotechnology》2010,87(3):1177-1185
In order to achieve high butanol production by Clostridium saccharoperbutylacetonicum N1-4, the effect of lactic acid on acetone–butanol–ethanol fermentation and several fed-batch cultures in which lactic acid
is fed have been investigated. When a medium containing 20 g/l glucose was supplemented with 5 g/l of closely racemic lactic
acid, both the concentration and yield of butanol increased; however, supplementation with more than 10 g/l lactic acid did
not increase the butanol concentration. It was found that when fed a mixture of lactic acid and glucose, the final concentration
of butanol produced by a fed-batch culture was greater than that produced by a batch culture. In addition, a pH-controlled
fed-batch culture resulted in not only acceleration of lactic acid consumption but also a further increase in butanol production.
Finally, we obtained 15.5 g/l butanol at a production rate of 1.76 g/l/h using a fed-batch culture with a pH-stat continuous
lactic acid and glucose feeding method. To confirm whether lactic acid was converted to butanol by the N1-4 strain, we performed
gas chromatography–mass spectroscopy (GC-MS) analysis of butanol produced by a batch culture during fermentation in a medium
containing [1,2,3-13C3] lactic acid as the initial substrate. The results of the GC-MS analysis confirmed the bioconversion of lactic acid to butanol. 相似文献
11.
Production of Poly(3-hydroxybutyrate) from waste potato starch 总被引:1,自引:0,他引:1
There has been a considerable interest in using low cost carbon substrates for the production of Poly(3-hydroxybutyrate) (PHB). We have shown that saccharified waste potato starch can be used as a viable alternative carbon source in high cell density PHB production. Using Ralstonia eutropha NCIMB 11599 with phosphate limitation, 179 g/l biomass, 94 g/l PHB, Y(biomass/starch) = 0.46 g/g, Y(PHB/starch) = 0.22 g/g, and PHB productivity = 1.47 g/(l*h) were achieved. Residual maltose accumulated in the fed-batch reactor but caused no noticeable inhibition. Performance with saccharified starch was virtually identical to that with glucose. 相似文献
12.
Cell yield and toxicity of B. thuringiensis H-14 was improved markedly by adopting a simple fed-batch fermentation technique based on controlling glucose concentration. Maintenance of steady glucose concentration (0.3-0.5%) in the culture medium was achieved by the continuous addition of concentrated glucose solution. Addition of glucose at 3 g/hr/l of culture starting from 3rd hr till 16th hr of fermentation was found to yield cell densities of 80 g/l (wet weight) which represented a nearly 3-fold increase over the batch mode. A fivefold increase in toxicity was obtained by fed-batch fermentation. Cultivation of B. thuringiensis H-14 to high cell densities had no negative effect on sporulation and toxin synthesis. The rate of pH drop and dissolved oxygen level were within manageable limits. 相似文献
13.
Rhamnolipid is one of the most commonly used biosurfactants with the ability to reduce the surface tension of water from 72
to 30 mN/m. An indigenous isolate Pseudomonas
aeruginosa S2 possessing excellent ability to produce rhamnolipid was used as a model strain to explore fermentation technology for
rhamnolipid production. Using optimal medium and operating conditions (37°C, pH 6.8, and 250 rpm agitation) obtained from
batch fermentation, P. aeruginosa S2 was able to produce up to 5.31 g/l of rhamnolipid from glucose-based medium. To further improve the rhamnolipid yield,
a pH-stat fed-batch culture was performed by maintaining a constant pH of 6.8 through manipulating glucose feeding. The effect
of influent glucose concentration on rhamnolipid yield and productivity was investigated. Using the pH-stat culture, a maximum
rhamnolipid concentration (6.06 g/l) and production rate (172.5 ml/h/l) was obtained with 6% glucose in the feed. Moreover,
combining pH-stat culture with fill-and-draw operation allowed a stable repeated fed-batch operation for approximately 500 h.
A marked increase in rhamnolipid production was achieved, leading to the best rhamnolipid yield of approximately 9.4 g/l during
the second repeated run. 相似文献
14.
Demonstration of the Crabtree effect in Phaffia rhodozyma during continuous and fed-batch cultivation 总被引:3,自引:0,他引:3
By monitoring cell yield and fermentation products during fed-batch and continuous growth, Pfaffia rhodozyma was shown to exhibit the Crabtree effect. In fed-batch culture at feed concentrations of 27 and 55 g glucose/l there was good agreement between the observed biomass formation and that predicted by a mass balance model. At 125 g glucose/l in the feed, biomass formation was less than predicted and fermentation products such as ethanol and acetic acid accumulated in the culture medium. In continuous culture with a feed concentration of 10 g glucose/l, the Crabtree effect became apparent at a dilution rate of 0.1 h -1 . Aerobic fermentation did not occur provided the sugar substrate was maintained at a concentration of less than 0.5 g/l. Although the cell yield coefficient was reduced from 0.5 g/g to 0.16 g/g during aerobic fermentation, the carotenoid content of the cells was unaffected. 相似文献
15.
N. Padukone K. W. Evans J. D. McMillan C. E. Wyman 《Applied microbiology and biotechnology》1995,43(5):850-855
This work describes the characterization of recombinantEsherichia coli ATCC 11303 (pLOI 297) in the production of ethanol from cellulose and xylose. We have examined the fermentation of glucose
and xylose, both individually and in mixtures, and the selectivity of ethanol production under various conditions of operation.
Xylose metabolism was strongly inhibited by the presence of glucose. Ethanol was a strong inhibitor of both glucose and xylose
fermentations; the maximum ethanol levels achieved at 37°C and 42°C were about 50 g/l and 25 g/l respectively. Simmultaneous
sacharification and fermentation of cellulose with recombinantE. coli and exogenous cellulose showed a high ethanol yield (84% of theoretical) in the hydrolysis regime of pH 5.0 and 37°C. The
selectivity of organic acid formation relative to that of ethanol increased at extreme levels of initial glucose concentration;
production of succinic and acetic acids increased at low levels of glucose ( <1 g/l), and lactic acid production increased
when initial glucose was higher than 100 g/l. 相似文献
16.
Bélanger L Figueira MM Bourque D Morel L Béland M Laramée L Groleau D Míguez CB 《FEMS microbiology letters》2004,236(2):197-204
The green fluorescent protein (GFP) was used as a model protein to study the recombinant protein production by the strain Methylobacterium extorquens ATCC 55366. Scale-up from shake flasks to 20 l fed-batch fermentation was achieved using methanol as a sole carbon and energy source and a completely minimal culture medium. Two different expression vectors were used to express GFP. Clone PCM-GFP containing the vector pCM110 with native promoter of the methanol dehydrogenase PmxaF produced approximately 100-fold more GFP than the clone PRK-GFP containing the vector pRK310 with the heterogeneous promoter Plac. Several fed-batch fermentations with and without selective pressure (tetracycline) were run in a 20 l stirred tank fermenter using the two different clones of M. extorquens. The methanol concentration was monitored with an on-line semiconductor gas sensor in the culture broth. It was maintained at a non-toxic level of 1.4 g l(-1) with an adaptative control which regulates the methanol feed rate. The same growth profile was achieved in all fermentations. The maximum growth rate (micro(max)) was 0.18 h(-1) with an overall yield (Y(X/S)) of 0.3 g g(-1) methanol. With this high cell density fermentation process, we obtained high levels (up to 4 g l(-1)) of GFP with the clone PCM-GFP. The maximum specific GFP production (Y(GFP/X)) with this clone was 80 mg g(-1) representing approximately 16% of the total cell protein. Additional feeding of pure oxygen to the fermenter permitted a longer phase of exponential growth but had no effect on the total yields of biomass and GFP. The specific GFP production of clone PCM-GFP remained unaffected in the presence or absence of selective pressure (tetracycline), within the initial 50 h of the fermentation culture. These results suggest that M. extorquens ATCC 55366 could be an interesting candidate for overexpression of recombinant proteins. 相似文献
17.
2,3-Butanediol is an important bio-based chemical product, because it can be converted into several C4 industrial chemicals. In this study, a lactate dehydrogenase-deleted mutant was constructed to improve 2,3-butanediol productivity in Enterobacter aerogenes. To delete the gene encoding lactate dehydrogenase, λ Red recombination method was successfully adapted for E. aerogenes. The resulting strain produced a very small amount of lactate and 16.7% more 2,3-butanediol than that of the wild-type strain in batch fermentation. The mutant and its parental strain were then cultured with six different carbon sources, and the mutant showed higher carbon source consumption and microbial growth rates in all media. The 2,3-butanediol titer reached 69.5 g/l in 54 h during fed-batch fermentation with the mutant,which was 27.4% higher than that with the parental strain.With further optimization of the medium and aeration conditions,118.05 g/l 2,3-butanediol was produced in 54 h during fed-batch fermentation with the mutant. This is by far the highest titer of 2,3-butanediol with E. aerogenes achieved by metabolic pathway engineering. 相似文献
18.
Ibrar Khan Kiran Nazir Zhi-Peng Wang Guang-Lei Liu Zhen-Ming Chi 《Applied microbiology and biotechnology》2014,98(4):1539-1546
In this study, after screening of eight fungal strains for their ability to produce calcium malate, it was found that Penicillium viticola 152 isolated from marine algae among them could produce the highest titer of calcium malate. At the same time, it was found that corn steep liquor (CSL) could stimulate calcium malate production and 0.5 % (v/v) CSL was the most suitable for calcium malate production. Under the optimal conditions, a titer of calcium malate in the supernatant was 132 g/l at flask level. During a 10-l fermentation, a titer of 168 g/l, a yield of 1.28 g/g of glucose, and a productivity of 1.75 g/l/h were reached within 96 h of the fermentation, and 93.4 % of the sugar was used for calcium malate production and cell growth, demonstrating that the titer, yield, and productivity of calcium malate by this fungal strain were very high and the fermentation period was very short. After analysis of the partially purified product with high-performance liquid chromatography, it was found that the main product was calcium malate. The results demonstrated that P. viticola 152 obtained in this study was the most suitable for developing a novel one-step fermentation process for calcium malate production from glucose on a large scale. 相似文献
19.
Actinoplanes utahensis ZJB-08196 fed-batch fermentation at elevated osmolality for enhancing acarbose production 总被引:1,自引:0,他引:1
Acarbose, a potent α-glucosidase inhibitor, is as an oral anti-diabetic drug for treatment of the type two, noninsulin-dependent diabetes. Actinoplanes utahensis ZJB-08196, an osmosis-resistant actinomycete, had a broad osmolality optimum between 309 mOsm kg−1 and 719 mOsm kg−1. Utilizing this unique feature, an fed-batch culture process under preferential osmolality was constructed through intermittently feeding broths with feed medium consisting of 14.0 g l−1 maltose, 6.0 g l−1 glucose and 9.0 g l−1 soybean meal, at 48 h, 72 h, 96 h and 120 h. This intermittent fed-batch culture produced a peak acarbose titer of 4878 mg l−1, increased by 15.9% over the batch culture. 相似文献
20.
Ya-Jun Wang Li-Ling Liu Zhi-Hua Feng Zhi-Qiang Liu Yu-Guo Zheng 《World journal of microbiology & biotechnology》2011,27(12):2759-2766
Acarbose is a clinically useful drug for the treatment of type II, insulin-independent diabetes as a hypoglycemic agent. An
acarbose-overproducing strain ZJB-08196, indentified as Actinoplanes utahensis, was able to produce 4,210 mg l−1 of acarbose at 591 mOsm kg−1 with the optimized conditions at bench scale. Shake flask fermentation showed that maltose, glycerol and monosodium glutamate
were supportive for acarbose production; soybean meal had higher bioavailability than corn steep liquor. Moreover, acarbose
formation was not parallel with mycelial growth and the pattern of acarbose production by A. utahensis ZJB-08196 was the type of mixed-growth associated. 相似文献