共查询到20条相似文献,搜索用时 31 毫秒
1.
Sachin Kumar Surendra P. Singh Indra M. Mishra Dilip K. Adhikari 《Journal of industrial microbiology & biotechnology》2009,36(12):1483-1489
A yeast strain Kluyveromyces sp. IIPE453 (MTCC 5314), isolated from soil samples collected from dumping sites of crushed sugarcane bagasse in Sugar Mill,
showed growth and fermentation efficiency at high temperatures ranging from 45°C to 50°C. The yeast strain was able to use
a wide range of substrates, such as glucose, xylose, mannose, galactose, arabinose, sucrose, and cellobiose, either for growth
or fermentation to ethanol. The strain also showed xylitol production from xylose. In batch fermentation, the strain showed
maximum ethanol concentration of 82 ± 0.5 g l−1 (10.4% v/v) on initial glucose concentration of 200 g l−1, and ethanol concentration of 1.75 ± 0.05 g l−1 as well as xylitol concentration of 11.5 ± 0.4 g l−1 on initial xylose concentration of 20 g l−1 at 50°C. The strain was capable of simultaneously using glucose and xylose in a mixture of glucose concentration of 75 g l−1 and xylose concentration of 25 g l−1, achieving maximum ethanol concentration of 38 ± 0.5 g l−1 and xylitol concentration of 14.5 ± 0.2 g l−1 in batch fermentation. High stability of the strain was observed in a continuous fermentation by feeding the mixture of glucose
concentration of 75 g l−1 and xylose concentration of 25 g l−1 by recycling the cells, achieving maximum ethanol concentration of 30.8 ± 6.2 g l−1 and xylitol concentration of 7.35 ± 3.3 g l−1 with ethanol productivity of 3.1 ± 0.6 g l−1 h−1 and xylitol productivity of 0.75 ± 0.35 g l−1 h−1, respectively. 相似文献
2.
Kim YS Lee JH Kim NH Yeom SJ Kim SW Oh DK 《Applied microbiology and biotechnology》2011,90(2):489-497
In the fed-batch culture of glycerol using a metabolically engineered strain of Escherichia coli, supplementation with glucose as an auxiliary carbon source increased lycopene production due to a significant increase in
cell mass, despite a reduction in specific lycopene content. l-Arabinose supplementation increased lycopene production due to increases in cell mass and specific lycopene content. Supplementation
with both glucose and l-arabinose increased lycopene production significantly due to the synergistic effect of the two sugars. Cell growth by the
consumption of carbon sources was related to endogenous metabolism in the host E. coli. Supplementation with l-arabinose stimulated only the mevalonate pathway for lycopene biosynthesis and supplementation with both glucose and l-arabinose stimulated synergistically only the mevalonate pathway. In the fed-batch culture of glycerol with 10 g l−1 glucose and 7.5 g l−1
l-arabinose, the cell mass, lycopene concentration, specific lycopene content, and lycopene productivity after 34 h were 42 g l−1, 1,350 mg l−1, 32 mg g cells−1, and 40 mg l−1 h−1, respectively. These values were 3.9-, 7.1-, 1.9-, and 11.7-fold higher than those without the auxiliary carbon sources,
respectively. This is the highest reported concentration and productivity of lycopene. 相似文献
3.
Mendes FS González-Pajuelo M Cordier H François JM Vasconcelos I 《Applied microbiology and biotechnology》2011,92(3):519-527
In this work, the production of 1,3-propanediol from glucose and molasses was studied in a two-step process using two recombinant
microorganisms. The first step of the process is the conversion of glucose or other sugar into glycerol by the metabolic engineered
Saccharomyces cerevisiae strain HC42 adapted to high (>200 g l−1) glucose concentrations. The second step, carried out in the same bioreactor, was performed by the engineered strain Clostridium acetobutylicum DG1 (pSPD5) that converts glycerol to 1,3-propanediol. This two-step strategy led to a flexible process, resulting in a 1,3-propanediol
production and yield that depended on the initial sugar concentration. Below 56.2 g l−1 of sugar concentration, cultivation on molasses or glucose showed no significant differences. However, at higher molasses
concentrations, glycerol initially produced by yeast could not be totally converted into 1,3-propanediol by C. acetobutylicum and a lower 1,3-propanediol overall yield was observed. In our hand, the best results were obtained with an initial glucose
concentration of 103 g l−1, leading to a final 1,3-propanediol concentration of 25.5 g l−1, a productivity of 0.16 g l−1 h−1 and 1,3-propanediol yields of 0.56 g g−1 glycerol and 0.24 g g−1 sugar, which is the highest value reported for a two-step process. For an initial sugar concentration (from molasses) of
56.2 g l−1, 27.4 g l−1 of glycerol were produced, leading to 14.6 g l−1 of 1.3-propanediol and similar values of productivity, 0.15 g l−1 h−1, and overall yield, 0.26 g g−1 sugar. 相似文献
4.
Compared with steady state, oscillation in continuous very-high-gravity ethanol fermentation with Saccharomyces cerevisiae improved process productivity, which was thus introduced for the fermentation system composed of a tank fermentor followed
by four-stage packed tubular bioreactors. When the very-high-gravity medium containing 280 g l−1 glucose was fed at the dilution rate of 0.04 h−1, the average ethanol of 15.8% (v/v) and residual glucose of 1.5 g l−1 were achieved under the oscillatory state, with an average ethanol productivity of 2.14 g h−1 l−1. By contrast, only 14.8% (v/v) ethanol was achieved under the steady state at the same dilution rate, and the residual glucose was as high as 17.1 g l−1, with an ethanol productivity of 2.00 g h−1 l−1, indicating a 7% improvement under the oscillatory state. When the fermentation system was operated under the steady state
at the dilution rate of 0.027 h−1 to extend the average fermentation time to 88 h from 59 h, the ethanol concentration increased slightly to 15.4% (v/v) and residual glucose decreased to 7.3 g l−1, correspondingly, but the ethanol productivity was decreased drastically to 1.43 g h−1 l−1, indicating a 48% improvement under the oscillatory state at the dilution rate of 0.04 h−1. 相似文献
5.
Lang YJ Bai L Ren YN Zhang LH Nagata S 《Extremophiles : life under extreme conditions》2011,15(2):303-310
Using ectoine-excreting strain Halomonas salina DSM 5928T, we developed a new process for high-efficiency production of ectoine, which involved a combined process of batch fermentation
by growing cells and production by resting cells. In the first stage, batch fermentation was carried out using growing cells
under optimal fermentation conditions. The second stage was the production phase, in which ectoine was synthesized and excreted
by phosphate-limited resting cells. Optimal conditions for synthesis and excretion of ectoine during batch fermentation in
a 10 l fermentor were 0.5 mol l−1 NaCl and an initial monosodium glutamate concentration of 80 g l−1 respectively. The pH was adjusted to 7.0 and the temperature was maintained at 33°C. In phosphate-limited resting cells medium,
monosodium glutamate and NaCl concentration was 200 g l−1 and 0.5 mol l−1, respectively, as well as pH was 7.0. The total concentration of ectoine produced was 14.86 g l−1, the productivity and yield of ectoine was 7.75 g l−1 day−1 and 0.14 g g−1, respectively, and the percentage of ectoine excreted was 79%. These levels of ectoine production and excretion are the highest
reported to date. 相似文献
6.
Octavio Carvajal-Zarrabal Cirilo Nolasco-Hipólito Kopli B. Bujang Ayaaki Ishizaki 《Journal of industrial microbiology & biotechnology》2009,36(3):409-415
A membrane bioreactor for production of nisin Z was constructed using Lactococcus lactis IO-1 in continuous culture using hydrolyzed sago starch as carbon source. A strategy used to enhance the productivity of
nisin Z was to maintain the cells in a continuous growth at high cell concentration. This resulted in a volumetric productivity
of nisin Z, as 50,000 IU l−1 h−1 using a cell concentration of 15 g l−1, 30°C, pH 5.5 and a dilution rate of 1.24 h−1. Adding 10 g l−1 YE and 2 g l−1 polypeptone, other inducers were unnecessary to maintain production of nisin. The operating conditions of the reactor removed
nisin and lactate, thus minimizing their effects which allowed the maintenance of cells in continuous exponential growth phase
mode with high metabolic activity. 相似文献
7.
Methee Khamduang Kanoktip Packdibamrung Jarun Chutmanop Yusuf Chisti Penjit Srinophakun 《Journal of industrial microbiology & biotechnology》2009,36(10):1267-1274
The production of l-phenylalanine is conventionally carried out by fermentations that use glucose or sucrose as the carbon source. This work
reports on the use of glycerol as an inexpensive and abundant sole carbon source for producing l-phenylalanine using the genetically modified bacterium Escherichia coli BL21(DE3). Fermentations were carried out at 37°C, pH 7.4, using a defined medium in a stirred tank bioreactor at various
intensities of impeller agitation speeds (300–500 rpm corresponding to 0.97–1.62 m s−1 impeller tip speed) and aeration rates (2–8 L min−1, or 1–4 vvm). This highly aerobic fermentation required a good supply of oxygen, but intense agitation (impeller tip speed
~1.62 m s−1) reduced the biomass and l-phenylalanine productivity, possibly because of shear sensitivity of the recombinant bacterium. Production of l-phenylalanine was apparently strongly associated with growth. Under the best operating conditions (1.30 m s−1 impeller tip speed, 4 vvm aeration rate), the yield of l-phenylalanine on glycerol was 0.58 g g−1, or more than twice the best yield attainable on sucrose (0.25 g g−1). In the best case, the peak concentration of l-phenylalanine was 5.6 g L−1, or comparable to values attained in batch fermentations that use glucose or sucrose. The use of glycerol for the commercial
production of l-phenylalanine with E. coli BL21(DE3) has the potential to substantially reduce the cost of production compared to sucrose- and glucose-based fermentations. 相似文献
8.
Rhamnolipid biosurfactant production by Pseudomonas nitroreducens isolated from petroleum-contaminated soil was investigated. The effects of carbon, nitrogen and carbon to nitrogen ratio
on biosurfactant production were examined using mineral salts medium as the growth medium. The tenso-active properties (surface
activity and critical micelle concentrations of the produced biosurfactant were also evaluated. The best carbon source, nitrogen
source were glucose and sodium nitrate giving rhamnolipid yields of 5.28 and 4.38 g l−1, respectively. The maximum rhamnolipid production of 5.46 g l−1 was at C/N (glucose/sodium nitrate) of 22. The rhamnolipid biosurfactant reduced the surface tension of water from 72 to
~37 mN/m. It also has critical micelle concentration of ~28 mg l−1. Thus, the results presented in our reports show that the produced rhamnolipid can find wide applications in various bioremediation
activities such as enhanced oil recovery and petroleum degradation. 相似文献
9.
Guo T Tang Y Zhang QY Du TF Liang DF Jiang M Ouyang PK 《Journal of industrial microbiology & biotechnology》2012,39(3):401-407
Clostridium beijerinckii mutant strain IB4, which has a high level of inhibitor tolerance, was screened by low-energy ion implantation and used for
butanol fermentation from a non-detoxified hemicellulosic hydrolysate of corn fiber treated with dilute sulfuric acid (SAHHC).
Evaluation of toxicity showed C. beijerinckii IB4 had a higher level of tolerance than parent strain C. beijerinckii NCIMB 8052 for five out of six phenolic compounds tested (the exception was vanillin). Using glucose as carbon source, C. beijerinckii IB4 produced 9.1 g l−1 of butanol with an acetone/butanol/ethanol (ABE) yield of 0.41 g g−1. When non-detoxified SAHHC was used as carbon source, C. beijerinckii NCIMB 8052 grew well but ABE production was inhibited. By contrast, C. beijerinckii IB4 produced 9.5 g l−1 of ABE with a yield of 0.34 g g−1, including 2.2 g l−1 acetone, 6.8 g l−1 butanol, and 0.5 g l−1 ethanol. The remarkable fermentation and inhibitor tolerance of C. beijerinckii IB4 appears promising for ABE production from lignocellulosic materials. 相似文献
10.
Guggulsterone, a hypolipidemic natural agent, is produced in resin canals of the plant Commiphora wightii. In this study, the stimulatory effects of growth retardants [ALAR (N,N-dimethylaminosuccinamic acid) and CCC (chlormequat chloride)] and fungal elicitor on guggulsterone accumulation in cell cultures
of C. wightii are reported. CCC at 1 mg l−1 enhanced guggulsterone content (~123 μg l−1) when added on the fifth day after inoculation, while ALAR at 2.5 mg l−1 increased guggulsterone content (~116 μg l−1) when added on the tenth day. In a two-stage fed-batch process, combined treatment with fungal elicitor and growth retardant
caused a significant increase (~353 μg l−1) in guggulsterone content in cell cultures after 17 days of growth. This represents an approximately fivefold increase over
the guggulsterone contents in initial cultures of this plant. 相似文献
11.
Dan Wang Qiang Li Yu Mao Jianmin Xing Zhiguo Su 《Applied microbiology and biotechnology》2010,87(6):2025-2035
Escherichia coli strains with foreign genes under the isopropyl-β-d-thiogalactopyranoside-inducible promoters such as lac, tac, and trc were engineered and considered as the promising succinic acid-producing bacteria in many reports. The promoters mentioned
above could also be induced by lactose, which had not been attempted for succinic acid production before. Here, the efficient
utilization of lactose as inducer was demonstrated in cultures of the ptsG, ldhA, and pflB mutant strain DC1515 with ppc overexpression. A fermentative process for succinic acid production at high level by this strain was developed. In flask
anaerobic culture, 14.86 g l−1 succinic acid was produced from 15 g l−1 glucose with a yield of 1.51 mol mol−1 glucose. In two-stage culture carried out in a 3-l bioreactor, the overall yield and concentration of succinic acid reached
to 1.67 mol mol−1 glucose and 99.7 g l−1, respectively, with a productivity of 1.7 g l−1 h−1 in the anaerobic stage. The efficient utilization of lactose as inducer made recombinant E. coli a more capable strain for succinic acid production at large scale. 相似文献
12.
Poly(3-hydroxybutyrate) (PHB) biosynthesis from soybean oil by Cupriavidus necator was studied using a bench scale bioreactor. The highest cell concentration (83 g l−1) was achieved using soybean oil at 40 g l−1 and a pulse of the same concentration. The PHB content was 81% (w/w), PHB productivity was 2.5 g l−1 h−1, and the calculated Yp/s value was 0.85 g g−1. Growth limitation and the onset of PHB biosynthesis took place due to exhaustion of P, and probably also Cu, Ca, and Fe. 相似文献
13.
Xin Zhao Cuimin Hu Siguo Wu Hongwei Shen Zongbao K. Zhao 《Journal of industrial microbiology & biotechnology》2011,38(5):627-632
Microbial lipid is a potential alternative feedstock for the biodiesel industry. New culture strategies remain to be developed
to improve the economics of microbial lipid technology. This work describes lipid production by the oleaginous yeast Rhodosporidium toruloides Y4 using a 15-l bioreactor with different substrate feeding strategies. Among these strategies, the intermittent feeding
mode gave a lipid productivity of 0.36 g l−1 h−1, whereas the constant glucose concentration II (CC-II) mode gave the highest lipid productivity of 0.57 g l−1 h−1. The repeated fed-batch mode according to the CC-II mode was performed with a duration time of 358 h, and the overall lipid
productivity was 0.55 g l−1 h−1. Our results suggested that substrate feeding modes had a great impact on lipid productivity and that the repeated fed-batch
process was the most appealing method by which to enhance microbial lipid production. 相似文献
14.
Laura Pinilla Rodrigo Torres Claudia Ortiz 《World journal of microbiology & biotechnology》2011,27(11):2521-2528
Two wild strains of Zymomonas mobilis were isolated (named as ML1 and ML2) from sugar cane molasses obtained from different farms of Santander, Colombia. Initially,
selection of the best ethanol-producer strains was carried out using ethanol production parameters obtained with a commercial
strain Z. mobilis DSM 3580. Three isolated strains were cultivated in a culture medium containing yeast extract, peptone, glucose and salts,
at pH 6 and 32°C with stirring rate of 65 rpm during 62 h. The best results of ethanol production were obtained with the native
strain ML1, reaching a maximum ethanol concentration of 79.78 g l−1. ML1 and ML2 strains were identified as Z.
mobilis, according to the morphology, biochemical tests and molecular characterization by PCR of specific DNA sequences from Z. mobilis. Subsequently, the effect of different nitrogen sources on production of ethanol was evaluated. The best results were obtained
using urea at a 0.73 g/l. In this case, maximum concentration of ethanol was 83.81 g l−1, with kinetic parameters of yield of ethanol on biomass (YP/X) = 69.01(g g−1), maximum volumetric productivity of ethanol (Qpmax) = 2.28 (g l−1 h−1), specific productivity of ethanol (qP) = 3.54 (h−1) and specific growth rate (μ) = 0.12 h−1. Finally, we studied the effect of different culture conditions (pH, temperature, stirring, C/N ratio) with a Placket-Burman′s
experimental design. This optimization indicated that the most significant variables were temperature and stirring. In the
best culture conditions a significant increase in all variables of response was achieved, reaching a maximum ethanol concentration
of 93.55 g l−1. 相似文献
15.
Maltose and yeast extract were the most favourable carbon and nitrogen sources for exopolysaccharide production by submerged
culture of Shiraia bambusicola WZ-003, and initial maltose and yeast extract concentrations were at 30 and 3 g l−1, respectively. Plant oils could increase the mycelial growth and exopolysaccharide production in tested concentration. K+ and Mg2+ could enhance the mycelial growth and exopolysaccharide biosynthesis. The optimal cultivation temperature and initial pH
were found to be 26°C and 6.0, respectively. Exopolysaccharide concentration reached 0.53 g l−1 in 15-l fermenter under optimal nutritional conditions. 相似文献
16.
Biomass and lipid productivities of Chlorella vulgaris under different growth conditions were investigated. While autotrophic growth did provide higher cellular lipid content (38%),
the lipid productivity was much lower compared with those from heterotrophic growth with acetate, glucose, or glycerol. Optimal
cell growth (2 g l−1) and lipid productivity (54 mg l−1 day−1) were attained using glucose at 1% (w/v) whereas higher concentrations were inhibitory. Growth of C. vulgaris on glycerol had a similar dose effects as those from glucose. Overall, C. vulgaris is mixotrophic. 相似文献
17.
Butanol, a four-carbon primary alcohol (C4H10O), is an important industrial chemical and has a good potential to be used as a superior biofuel. Bio-based production of
butanol from renewable feedstock is a promising and sustainable alternative to substitute petroleum-based fuels. Here, we
report the development of a process for butanol production from glycerol, which is abundantly available as a byproduct of
biodiesel production. First, a hyper butanol producing strain of Clostridium pasteurianum was isolated by chemical mutagenesis. The best mutant strain, C. pasteurianum MBEL_GLY2, was able to produce 10.8 g l−1 butanol from 80 g l−1 glycerol as compared to 7.6 g l−1 butanol produced by the parent strain. Next, the process parameters were optimized to maximize butanol production from glycerol.
Under the optimized batch condition, the butanol concentration, yield, and productivity of 17.8 g l−1, 0.30 g g−1, and 0.43 g l−1 h−1 could be achieved. Finally, continuous fermentation of C. pasteurianum MBEL_GLY2 with cell recycling was carried out using glycerol as a major carbon source at several different dilution rates.
The continuous fermentation was run for 710 h without strain degeneration. The acetone–butanol–ethanol productivity and the
butanol productivity of 8.3 and 7.8 g l−1 h−1, respectively, could be achieved at the dilution rate of 0.9 h−1. This study reports continuous production of butanol with reduced byproducts formation from glycerol using C. pasteurianum, and thus could help design a bioprocess for the improved production of butanol. 相似文献
18.
Changhua Hu Yi Zou Wenting Zhao 《World journal of microbiology & biotechnology》2009,25(10):1705-1711
Effect of soybean oil on mycelial biomass and pleuromutilin biosynthesis by Pleurotus mutilis-04 was investigated in shake flask culture. The maximum pleuromutilin production and mycelial biomass were 8.32 ± 0.02 g l−1 and 49.10 ± 1.00 g l−1 when 20 g l−1 soybean oil was fed at 24 and 96 h respectively. A repeated fed-batch fermentation strategy with feeding 3 g l−1 soybean oil from 96 to 144 h at 24 h intervals was developed successfully to maintain mycelial growth and provide abundant
fatty acids for pleuromutilin biosynthesis. Compared with glucose as the sole carbon source, soybean oil was obviously beneficial
for the production of pleuromutilin. The results suggested that manipulation of metabolic regulation by soybean oil was an
effective way to enhance the production pleuromutilin. 相似文献
19.
The effects of initial culture pH ranging from 5.0 to 7.5 on biomass content, precursor 3-hydroxy-2-butanone (HB) accumulation,
and 2,3,5,6-tetramethylpyrazine (TTMP) formation by Bacillus subtilis CCTCC M 208157 were investigated in shake flask fermentation. Weak acidic conditions were found to favor cell growth and
precursor HB accumulation, while TTMP could be synthesized more efficiently in conditions with initial pH towards neutrality.
Batch bioprocess of TTMP fermentation by Bacillus subtilis CCTCC M 208157 at various controlled pH values ranging from 5.5 to 7.0 was then examined in 7.5-l fermentor. The results
suggested that optimum pH for cell growth and precursor HB accumulation was 5.5 with maximum cell growth rate (Q
x) and precursor HB accumulation rate (Q
HB) of 0.833 g l−1 h−1 and 1.118 g l−1 h−1, respectively, while optimum pH for TTMP formation was 7.0 with maximum TTMP formation rate (Q
TTMP) of 0.095 g l−1 h−1. A pH-shifted strategy was accordingly developed to improve TTMP production in bioreactor fermentation by shifting the culture
pH from 5.5 to 7.0 after 48 h of cultivation. By applying the strategy, final TTMP concentration of 7.43 g l−1 was obtained, being 22.2% greater than that of constant-pH fermentation. 相似文献
20.
The optimal reaction conditions for the conversion of oleic acid to 10-hydroxystearic acid by whole cells of Stenotrophomonas nitritireducens were: pH 7.5, 35°C, 0.05% (w/v) Tween 80, 20 g cells l−1, and 30 g oleic acid l−1 in an anaerobic atmosphere. Under these conditions, the cells produced 31.5 g 10-hydroxystearic acid l−1 over 4 h with a conversion yield of 100% (mol/mol) and a productivity of 7.9 g l−1 h−1, indicating that oleic acid was converted completely to 10-hydroxystearic acid, with no detectable byproduct. This is the
highest concentration, productivity, and yield of 10-hydroxystearic acid from oleic acid reported thus far. 相似文献