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1.
Instead of the conventional carbon sources used for propionic acid biosynthesis, the utilization of glycerol is considered
here, since the metabolic pathway involved in the conversion of glycerol to propionic acid is redox-neutral and energetic.
Three strains, Propionibacterium acidipropionici, Propionibacterium acnes and Clostridium propionicum were tested for their ability to convert glycerol to propionic acid during batch fermentation with initially 20 g/l glycerol.
P. acidipropionici showed higher efficiency in terms of fermentation time and conversion yield than did the other strains. The fermentation
profile of this bacterium consisted in propionic acid as the major product (0.844 mol/mol), and in minimal by-products: succinic
(0.055 mol/mol), acetic (0.023 mol/mol) and formic (0.020 mol/mol) acids and n-propanol (0.036 mol/mol). The overall propionic acid productivity was 0.18 g l−1h−1. A comparative study with glucose and lactic acid as carbon sources showed both less diversity in end-product composition
and a 17% and 13% lower propionic acid conversion yield respectively than with glycerol. Increasing the initial glycerol concentration
resulted in an enhanced productivity up to 0.36 g l−1h−1 and in a maximal propionic acid concentration of 42 g/l, while a slight decrease of the conversion yield was noticed. Such
a propionic acid production rate was similar or higher than the values obtained with lactic acid (0.35 g l−1h−1) or glucose (0.28 g l−1h−1). These results demonstrated that glycerol is a carbon source of interest for propionic acid production.
Received: 15 July 1996 / Received revision: 11 November 1996 / Accepted: 11 November 1996 相似文献
2.
A comparative study was carried out in anaerobic batch cultures on 20 g/l of either glycerol or glucose using two propionibacteria
strains, Propionibacterium acidipropionici and Propionibacterium freudenreichii ssp. shermanii. In all cases, fermentation end-products were the same and consisted of propionic acid as the major product, acetic acid
as the main by-product and two minor metabolites, n-propanol and succinic acid. Evidence was provided that greater production of propionic acid by propionibacteria was obtained
with glycerol as carbon and energy sources. P. acidipropionici showed higher efficiency in glycerol conversion to propionic acid with a faster substrate consumption (0.64 g l−1 h−1) and a higher propionic acid production (0.42 g l−1 h−1 and 0.79 mol/mol). The almost exclusive production of propionic acid from glycerol by this bacterium suggested an homopropionic
tendency of this fermentation. Acetic acid final concentration was two times lower on glycerol (2 g/l) than on glucose (4 g/l)
for both micro-organisms. P. freudenreichii ssp. shermanii exhibited a glycerol fermentation pattern typical of non-associated glycerol-consumption-product formation. This could indicate
a particular metabolism for P. freudenreichii ssp. shermanii oriented towards the production of other specific components. These results tend to show that glycerol could be an excellent
alternative to conventional carbon sources such as carbohydrates for propionic acid production.
Received: 21 May 1999 / Accepted: 1 November 1999 相似文献
3.
The potential use of spin filter device to retainPropionibacterium acidipropionici in the bioreactor under continuous mode of fermentation and improve propionic acid productivity, was examined. The yield
of propionic acid based on lactose concentration was 51% in batch and 54% in continuous (dilution rate=0.05 h−1) operation. The yield in continuous fermentation with cell retention using spin filter of 10 micron size (dilution rate=0.05
h−1) was even higher at 70% (w/w). The volumetric productivity under batch and continuous mode of operation were 0.312 g L−1 h−1 and 0.718 g L−1 h−1 respectively. Continuous fermentation with cell retention demonstrated even higher volumetric productivities at 0.98 g L−1 h−1 with out clogging problems It could be used for utilization of cheese whey to produce propionic acid at higher yield and
productivities. 相似文献
4.
Candida cylindracea NRRL Y-17506 was grown to produce extracellular lipase from oleic acid as a carbon source. Through flask cultures, it was found that the optimum initial oleic acid concentration for cell growth was 20 g l−1. However, high initial concentrations of oleic acid up to 50 g l−1 were not inhibitory. The highest extracellular lipase activity obtained in flask culture was 3.0 U ml−1 after 48 h with 5 g l−1 of initial oleic acid concentration. Fed-batch cultures (intermittent and stepwise feeding) were carried out to improve cell concentration and lipase activity. For the intermittent feeding fed-batch culture, the final cell concentration was 52 g l−1 and the extracellular lipase activity was 6.3 U ml−1 at 138.5 h. Stepwise feeding fed-batch cultures were carried out to simulate an exponential feeding and to investigate the effects of specific growth rate (0.02, 0.04 and 0.08 h−1) on cell growth and lipase production. The highest final cell concentration obtained was 90 g l−1 when the set point of specific growth rate (μset) was 0.02 h−1. High specific growth rate (0.04 and 0.08 h−1) decreased extracellular lipase production in the later part of fed-batch cultures due to build-up of the oleic acid oversupplied. The highest extracellular lipase activity was 23.7 U ml−1 when μset was 0.02 h−1, while the highest lipase productivity was 0.31 U ml−1 h−1 at μset of 0.08 h−1. 相似文献
5.
Quesada-Chanto A. Schmid-Meyer A.C. Schroeder A.G. Carvalho-Jonas M.F. Blanco I. Jonas R. 《World journal of microbiology & biotechnology》1998,14(6):843-846
Propionibacterium shermanii CDB 10015 was able to grow at different volumetric oxygen transfer coefficients (KLa) of 10, 22, 53h–1. These results demonstrate that this bacterium, known as anaerobic, is able to grow well under aerobic conditions. The cell biomass increased from 7.9 in anaerobic conditions to 18.3g/l at KLa 53h–1, increasing also the cell yield from 0.3 to 0.7g/g. The organic acid production pattern also changed with aeration. The acetic: propionic acid ratio increased from 0.38 in anaerobiosis to 6.25 at KLa 53h–1. The vitamin B12 production decreased from 3.1mg/l in anaerobiosis to 0.5mg/l at KLa 53h–1. 相似文献
6.
Rafael C. S. Rocha Luiziana F. da Silva Marilda K. Taciro José G. C. Pradella 《World journal of microbiology & biotechnology》2008,24(3):427-431
The biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from sucrose and propionic acid by Burkholderia sacchari IPT 189 was studied using a two-stage bioreactor process. In the first stage, this bacterium was cultivated in a balanced
culture medium until sucrose exhaustion. In the second stage, a solution containing sucrose and propionic acid as carbon source
was fed to the bioreactor at various sucrose/propionic acid (s/p) ratios at a constant specific flow rate. Copolymers with
3HV content ranging from 40 down to 6.5 (mol%) were obtained with 3HV yield from propionic acid (Y
3HV/prop) increasing from 1.10 to 1.34 g g−1. Copolymer productivity of 1 g l−1 h−1 was obtained with polymer biomass content rising up to 60% by increasing a specific flow rate at a constant s/p ratio. Increasing
values of 3HV content were obtained by varying the s/p ratios. A simulation of production costs considering Y
3HV/prop obtained in the present work indicated that a reduction of up to 73% can be reached, approximating US$ 1.00 per kg which
is closer to the value to produce P3HB from sucrose (US$ 0.75 per kg). 相似文献
7.
Yin Liu Yong-Guang Zhang Ru-Bing Zhang Fan Zhang Jianhang Zhu 《Current microbiology》2011,62(1):152-158
Cosubstrates fermentation is such an effective strategy for increasing subject metabolic products that it could be available
and studied in propionic acid production, using glycerol and glucose as carbon resources. The effects of glycerol, glucose,
and their mixtures on the propionic acid production by Propionibacterium acidipropionici CGMCC1.2225 (ATCC4965) were studied, with the aim of improving the efficiency of propionic acid production. The propionic
acid yield from substrate was improved from 0.475 and 0.303 g g−1 with glycerol and glucose alone, respectively, to 0.572 g g−1 with co-fermentation of a glycerol/glucose mixture of 4/1 (mol/mol). The maximal propionic acid and substrate conversion
rate were 21.9 g l−1 and 57.2% (w/w), respectively, both significantly higher than for a sole carbon source. Under optimized conditions of fed-batch
fermentation, the maximal propionic acid yield and substrate conversion efficiency were 29.2 g l−1 and 54.4% (w/w), respectively. These results showed that glycerol/glucose co-fermentation could serve as an excellent alternative
to conventional propionic acid fermentation. 相似文献
8.
Summary This paper presents a study of propionic acid and propionibacteria production from whey by usingPropionibacterium acidi-propionici in continuous fermentation with cell recycle. The highest propionic acid volumetric productivity achieved was 5 g.l–1.h–1 with no biomass bleeding. A maximal biomass concentration of 130 g.l–1 was achieved before initiating biomass bleeding to give a biomass volumetric productivity of 3.2 g.l–1.h–1 with a biomass of 75 g.l–1 and a propionic acid productivity of 3.6 g.l–1.h–1 (for about 100 hours i.e. more than 50 residence times). 相似文献
9.
Pseudomonas putida KT2440 grew on glucose at a specific rate of 0.48 h−1 but accumulated almost no poly-3-hydroxyalkanoates (PHA). Subsequent nitrogen limitation on nonanoic acid resulted in the
accumulation of only 27% medium-chain-length PHA (MCL-PHA). In contrast, exponential nonanoic acid-limited growth (μ = 0.15 h−1) produced 70 g l−1 biomass containing 75% PHA. At a higher exponential feed rate (μ = 0.25 h−1), the overall productivity was increased but less biomass (56 g l−1) was produced due to higher oxygen demand, and the biomass contained less PHA (67%). It was concluded that carbon-limited
exponential feeding of nonanoic acid or related substrates to cultures of P. putida KT2440 is a simple and highly effective method of producing MCL-PHA. Nitrogen limitation is unnecessary. 相似文献
10.
Actual and potential rates of hydrogen photoproduction by continuous culture of the purple non-sulphur bacterium Rhodobacter capsulatus 总被引:1,自引:1,他引:0
A. A. Tsygankov A. S. Fedorov T. V. Laurinavichene I. N. Gogotov K. K. Rao D. O. Hall 《Applied microbiology and biotechnology》1998,49(1):102-107
The influence of (NH4)2SO4 concentration and dilution rate (D) on actual and potential H2 photoproduction has been studied in ammonium-limited chemostat cultures of Rhodobacter capsulatus B10. The actual H2 production in a photobioreactor was maximal (approx. 80 ml h−1 l−1) at D = 0.06 h−1 and 4 mM (NH4)2SO4. However, it was lower than the potential H2 evolution (calculated from hydrogen evolution rates in incubation vials), which amounted to 100–120 ml h−1 l−1 at D = 0.03–0.08 h−1. Taking into account the fact that H2 production in the photobioreactor under these conditions was not limited by light or lactate, another limiting (inhibiting)
factor should be sought. One possibility is an inhibition of H2 production by the H2 accumulated in the gas phase. This is apparent from the non-linear kinetics of H2 evolution in the vials or from its inhibition by the addition of H2; initial rates were restored in both cases after the vials had been refilled with argon. The actual H2 production in the photobioreactor at D = 0.06 h−1 was shown to increase from approximately 80 ml h−1 l−1 to approximately 100 ml h−1 l−1 under an argon flow at 100 ml min−1. Under maximal H2 production rates in the photobioreactor, up to 30% of the lactate feedstock was utilised for H2 production and 50% for biomass synthesis.
Received: 22 April 1997 / Received revision: 14 July 1997 / Accepted: 27 July 1997 相似文献
11.
Corynebacterium acetoacidophilum RYU3161 was cultivated in al-histidine-limited fed-batch culture. To investigate the effect of cell growth on thel-proline production, 5l fed-batch culture was performed using an exponential feeding rate to obtain the specific growth rates (μ) of 0.04, 0.06,
0.08, and 0.1 h−1. The results show that the highest production ofl-proline was obtained at μ=0.04 h−1. The specificl-proline production rate (Qp) increased proportionally as a function of the specific growth rate, but decreased after it revealed the maximum value at
μ=0.08 h−1. Thus, the highest productivity ofl-proline was 1.66 g L−1 h−1 at μ=0.08 h−1. The results show that the production of L-proline inC. acetoacidophilum RYU3161 has mixed growth-associated characteristics. 相似文献
12.
Kinetics of kojic acid fermentation by Aspergillus flavus Link 44-1 using various sources of carbon [glucose, xylose, sucrose, starch, maltose, lactose or fructose] and nitrogen [NH4Cl, (NH4)2S2O8, (NH4)2NO3, yeast extract or peptone] were analyzed using models based on logistic and Luedeking–Piret equations. The highest kojic
acid production (39.90 g l−1) in submerged batch fermentation was obtained when 100 g l−1 glucose was used as a carbon source. Organic nitrogen sources such as peptone and yeast extract were favorable for kojic
acid production as compared to inorganic nitrogen sources. Yeast extract at 5 g l−1 was optimal. The optimal carbon to nitrogen (C/N) ratio for kojic acid fermentation was 93.3. In a resuspended cell system,
the rate of glucose conversion to kojic acid by cell-bound enzymes increased with increasing glucose concentration up to 70
g l−1, suggesting that the reaction followed the Michaelis–Menten enzyme kinetic model. The value of K
m and V
max for the reaction was 18.47 g l−1 glucose and 0.154 g l−1 h−1, respectively. Journal of Industrial Microbiology & Biotechnology (2000) 25, 20–24.
Received 13 October 1999/ Accepted in revised form 02 April 2000 相似文献
13.
Vogelaar JC Klapwijk B Temmink H van Lier JB 《Journal of industrial microbiology & biotechnology》2003,30(2):81-88
Kinetic parameters describing growth and decay of mesophilic (30°C) and thermophilic (55°C) aerobic biomass were determined
in continuous and batch experiments by using oxygen uptake rate measurements. Biomass was cultivated on a single soluble substrate
(acetate) in a mineral medium. The intrinsic maximum growth rate (μ
max) at 55°C was 0.71±0.09 h−1, which is 1.5 times higher than the μ
max at 30°C (0.48±0.11 h−1). The biomass decay rates increased from 0.004 h−1 at 30°C to 0.017 h−1 at 55°C. Monod constants were very low for both types of biomass: 9±2 mg chemical oxygen demand (COD) l−1at 30°C and 3±2 mg COD l−1at 55°C. Theoretical biomass yields were similar at 30 and 55°C: 0.5 g biomass COD (g acetate COD)−1. The observed biomass yields decreased under both temperature conditions as a function of the cell residence time. Under
thermophilic conditions, this effect was more pronounced due to the higher decay rates, resulting in lower biomass production
at 55°C compared to 30°C.
Electronic Publication 相似文献
14.
Ethanol production from hardwood spent sulfite liquor using an adapted strain of Pichia stipitis 总被引:1,自引:0,他引:1
J N Nigam 《Journal of industrial microbiology & biotechnology》2001,26(3):145-150
Conditions have been optimized for fermentation of pretreated hardwood spent sulfite liquor (HSSL) using an adapted strain
of Pichia stipitis. The pretreatments, consisting of boiling and overliming with Ca(OH)2 of HSSL, to partially remove inhibitors, and adaptation of the yeast strain to HSSL, were both critical for a successful
fermentation. Ethanol concentration was increased from 6.7 to 20.2 g l−1 using adapted P. stipitis (A) and pretreated HSSL. The maximum ethanol yield (Y
p/s) and productivity (Q
p) were 0.41 g g−1 and 0.44 g l−1 h−1, respectively, at an oxygen transfer rate of 2.0 mmol O2 l−1 h−1. The optimized results with this strain were compared to those of other xylose-fermenting yeasts and Saccharomyces cerevisiae (SSL-acclimatized) currently used at an industrial plant for the fermentation of spent sulfite liquor. Journal of Industrial Microbiology & Biotechnology (2001) 26, 145–150.
Received 23 June 2000/ Accepted in revised form 21 October 2000 相似文献
15.
Continuous production of l(+)-lactic acid by Lactobacillus casei in two-stage systems 总被引:2,自引:0,他引:2
Bruno-Bárcena JM Ragout AL Córdoba PR Siñeriz F 《Applied microbiology and biotechnology》1999,51(3):316-324
A two-stage two-stream chemostat system and a two-stage two-stream immobilized upflow packed-bed reactor system were used
for the study of lactic acid production by Lactobacillus casei subsp casei. A mixing ratio of D
12/D
2 = 0.5 (D = dilution rate) resulted in optimum production, making it possible to generate continuously a broth with high lactic acid
concentration (48 g l−1) and with a lowered overall content of initial yeast extract (5 g l−1), half the concentration supplied in the one-step process. In the two-stage chemostat system, with the first stage at pH
5.5 and 37 °C and a second stage at pH 6.0, a temperature change from 40 °C to 45 °C in the second stage resulted in a 100%
substrate consumption at an overall dilution rate of 0.05 h−1. To increase the cell mass in the system, an adhesive strain of L. casei was used to inoculate two packed-bed reactors, which operated with two mixed feedstock streams at the optimal conditions
found above. Lactic acid fermentation started after a lag period of cell growth over foam glass particles. No significant
amount of free cells, compared with those adhering to the glass foam, was observed during continuous lactic acid production.
The extreme values, 57.5 g l−1 for lactic acid concentration and 9.72 g l−1 h−1 for the volumetric productivity, in upflow packed-bed reactors were higher than those obtained for free cells (48 g l−1 and 2.42 g l−1 h−1) respectively and the highest overall l(+)-lactic acid purity (96.8%) was obtained in the two-chemostat system as compared with the immobilized-cell reactors (93%).
Received: 4 December 1997 / Received revision: 23 February 1998 / Accepted: 14 March 1998 相似文献
16.
The growth performance of malolactic fermenting bacteria Oenococcus oeni NCIMB 11648 and Lactobacillus brevis X2 was assessed in continuous culture. O. oeni grew at a dilution rate range of 0.007 to 0.052 h−1 in a mixture of 5:6 (g l−1) of glucose/fructose at an optimal pH of 4.5, and L. brevis X2 grew at 0.010 to 0.089 h−1 in 10 g l−1 glucose at an optimal pH of 5.5 in a simple and safe medium. The cell dry weight, substrate uptake and product formation
were monitored, as well as growth kinetics, yield parameters and fermentation balances were also evaluated under pH control
conditions. A comparison of growth characteristics of two strains was made, and this showed significantly different performance.
O. oeni has lower maximum specific growth rate (μmax=0.073 h−1), lower maximum cell productivity (Q
x
max=17.6 mg cell l−1 h−1), lower maximum biomass yield (Y
x/s
max=7.93 g cell mol−1 sugar) and higher maintenance coefficient (m
s=0.45 mmol−1 sugar g−1 cell h−1) as compared with L. brevis X2 (μmax=0.110 h−1; Q
x
max=93.2 g−1 cell mol−1 glucose; Y
x/s
max=22.3 g cell mol−1 glucose; m
s=0.21 mmol−1 glucose g−1 cell h−1). These data suggest a possible more productive strategy for their combined use in maturation of cider and wine. 相似文献
17.
Miho Sasaki Toru Jojima Masayuki Inui Hideaki Yukawa 《Applied microbiology and biotechnology》2010,86(4):1057-1066
Wild-type Corynebacterium glutamicum produced 0.6 g l−1 xylitol from xylose at a productivity of 0.01 g l−1 h−1 under oxygen deprivation. To increase this productivity, the pentose transporter gene (araE) from C. glutamicum ATCC31831 was integrated into the C. glutamicum R chromosome. Consequent disruption of its lactate dehydrogenase gene (ldhA), and expression of single-site mutant xylose reductase from Candida tenuis (CtXR (K274R)) resulted in recombinant C. glutamicum strain CtXR4 that produced 26.5 g l−1 xylitol at 3.1 g l−1 h−1. To eliminate possible formation of toxic intracellular xylitol phosphate, genes encoding xylulokinase (XylB) and phosphoenolpyruvate-dependent
fructose phosphotransferase (PTSfru) were disrupted to yield strain CtXR7. The productivity of strain CtXR7 increased 1.6-fold over that of strain CtXR4. A fed-batch
21-h CtXR7 culture in mineral salts medium under oxygen deprivation yielded 166 g l−1 xylitol at 7.9 g l−1 h−1, representing the highest bacterial xylitol productivity reported to date. 相似文献
18.
Lactic acid production from xylose by the fungus Rhizopus oryzae 总被引:1,自引:1,他引:0
Lignocellulosic biomass is considered nowadays to be an economically attractive carbohydrate feedstock for large-scale fermentation of bulk chemicals such as lactic acid. The filamentous fungus Rhizopus oryzae is able to grow in mineral medium with glucose as sole carbon source and to produce optically pure l(+)-lactic acid. Less is known about the conversion by R. oryzae of pentose sugars such as xylose, which is abundantly present in lignocellulosic hydrolysates. This paper describes the conversion of xylose in synthetic media into lactic acid by ten R. oryzae strains resulting in yields between 0.41 and 0.71 g g−1. By-products were fungal biomass, xylitol, glycerol, ethanol and carbon dioxide. The growth of R. oryzae CBS 112.07 in media with initial xylose concentrations above 40 g l−1 showed inhibition of substrate consumption and lactic acid production rates. In case of mixed substrates, diauxic growth was observed where consumption of glucose and xylose occurred subsequently. Sugar consumption rate and lactic acid production rate were significantly higher during glucose consumption phase compared to xylose consumption phase. Available xylose (10.3 g l−1) and glucose (19.2 g l−1) present in a mild-temperature alkaline treated wheat straw hydrolysate was converted subsequently by R. oryzae with rates of 2.2 g glucose l−1 h−1 and 0.5 g xylose l−1 h−1. This resulted mainly into the product lactic acid (6.8 g l−1) and ethanol (5.7 g l−1). 相似文献
19.
Automated feeding strategies for high-cell-density fed-batch cultivation of Pseudomonas putida KT2440 总被引:1,自引:0,他引:1
Four automatic substrate feeding strategies were developed and investigated in this study to obtain rapid, repeatable, and reliable high cell densities of Pseudomonas putida KT2440 from glucose. Growth yield data of the key nutrients, Y
X/Glucose, Y
X/NH4, Y
X/PO4, Y
X/Mg, and Y
CO2/Glucose, were determined to be 0.41, 5.44, 13.70, 236, and 0.65 g g−1, respectively. Although standard exponential feeding strategy worked well when the predetermined μ was set at 0.25 h−1, an exponential glucose feeding strategy with online μ
max estimation resulted in a higher average biomass productivity (3.4 vs 2.8 g l−1 h−1). A CO2 production rate based pulse glucose feeding strategy also resulted in good overall productivity (3.0 g l−1 h−1) and can be used as an alternative to pH-stat or DO-stat feeding. A cumulative CO2 production based continuous feed with real-time cumulative glucose consumption estimation resulted in much higher biomass productivity (4.3 g l−1 h−1) and appears to be an excellent and reliable approach to fully automating high-cell-density fed-batch cultivation of P. putida. 相似文献
20.
The mycelia of Aspergillus niger, cultivated in a medium containing 45 g l−1 maltose, 66 g l−1 yeast extract, and 5 g l−1 K2HPO4 at 30°C and 200 rpm, were used as a biocatalyst in the glucosylation of ascorbic acid. Free mycelia from 3-day-old culture,
when used in a 6-h reaction with maltose as the acyl donor, gave 16.07 g l−1 ascorbic acid glucoside corresponding to a volumetric productivity of 2.68 g l−1 h−1 and a conversion of 67%. Mycelia from 3-day-old cultures were entrapped in calcium alginate beads and used as a catalyst
in the glucosylation of ascorbic acid. An ascorbic acid-to-maltose molar ratio of 1:9 was found to be optimum, and the conversion
reached 75% after 12 h. The concentration of ascorbic acid glucoside produced at this molar ratio was 17.95 g l−1, and the productivity was 1.5 g l−1 h−1. The biocatalyst was repeatedly used in a fixed bed bioreactor for the synthesis of ascorbic acid glucoside and approximately
17 g l−1 of ascorbic acid glucoside corresponding to a volumetric productivity of 1.42 g l−1 h−1 was produced in each use. The conversion was retained at 70% in each use. The entrapped mycelia also exhibited exceptionally
high reusability and storage stability. The product was purified to 85% by anion exchange and gel permeation chromatography
with a final yield of 75%. 相似文献