共查询到20条相似文献,搜索用时 328 毫秒
1.
Fernández-López CL Torrestiana-Sánchez B Salgado-Cervantes MA García PG Aguilar-Uscanga MG 《Bioprocess and biosystems engineering》2012,35(4):605-614
Molasses “B” is a rich co-product of the sugarcane process. It is obtained from the second step of crystallization and is
richer in fermentable sugars (50–65%) than the final molasses, with a lower non-sugar solid content (18–33%); this co-product
also contains good vitamin and mineral levels. The use of molasses “B” for ethanol production could be a good option for the
sugarcane industry when cane sugar prices diminish in the market. In a complex medium like molasses, osmotolerance is a desirable
characteristic for ethanol producing strains. The aim of this work was to evaluate the use of molasses “B” for ethanol production
using Saccharomyces cerevisiae ITV-01 (a wild-type yeast isolated from sugarcane molasses) using different initial sugar concentrations (70–291 g L−1), two inoculum sizes and the addition of nutrients such as yeast extract, urea, and ammonium sulphate to the culture medium.
The results obtained showed that the strain was able to grow at 291 g L−1 total sugars in molasses “B” medium; the addition of nutrients to the culture medium did not produce a statistically significant
difference. This yeast exhibits high osmotolerance in this medium, producing high ethanol yields (0.41 g g−1). The best conditions for ethanol production were 220 g L−1 initial total sugars in molasses “B” medium, pH 5.5, using an inoculum size of 6 × 106 cell mL−1; ethanol production was 85 g L−1, productivity 3.8 g L−1 h−1 with 90% preserved cell viability. 相似文献
2.
Kameshnee Naidoo Manimaran Ayyachamy Kugen Permaul Suren Singh 《Bioprocess and biosystems engineering》2009,32(5):689-695
Xanthomonas campestris pv phaseoli produced an extracellular endoinulinase (9.24 ± 0.03 U mL−1) in an optimized medium comprising of 3% sucrose and 2.5% tryptone. X. campestris pv. phaseoli was further subjected to ethylmethanesulfonate mutagenesis and the resulting mutant, X. campestris pv. phaseoli KM 24 demonstrated inulinase production of 22.09 ± 0.03 U mL−1 after 18 h, which was 2.4-fold higher than that of the wild type. Inulinase production by this mutant was scaled up using
sucrose as a carbon source in a 5-L fermenter yielding maximum volumetric (21,865 U L−1 h−1) and specific (119,025 U g−1 h−1) productivities of inulinase after 18 h with an inulinase/invertase ratio of 2.6. A maximum FOS production of 11.9 g L−1 h−1 and specific productivity of 72 g g−1 h−1 FOS from inulin were observed in a fermenter, when the mutant was grown on medium containing 3% inulin and 2.5% tryptone.
The detection of mono- and oligosaccharides in inulin hydrolysates by TLC analysis indicated the presence of an endoinulinase.
This mutant has potential for large-scale production of inulinase and fructooligosaccharides. 相似文献
3.
Liu J Zhang Z Liu Z Zhu H Dang H Lu J Cui Z 《Marine biotechnology (New York, N.Y.)》2011,13(5):837-844
The aim of this work was to optimize the fermentation parameters in the shake-flask culture of marine bacterium Wangia sp. C52 to increase cold-adapted amylase production using two statistical experimental methods including Plackett–Burman
design, which was applied to find the key ingredients for the best medium composition, and response surface methodology, which
was used to determine the optimal concentrations of these components. The results showed starch, tryptone, and initial pH
had significant effects on the cold-adapted amylase production. A central composite design was then employed to further optimize
these three factors. The experimental results indicated that the optimized composition of medium was 6.38 g L−1 starch, 33.84 g L−1 tryptone, 3.00 g L−1 yeast extract, 30 g L−1 NaCl, 0.60 g L−1 MgSO4 and 0.56 g L−1 CaCl2. The optimized cultivation conditions for amylase production were pH 7.18, a temperature of 20°C, and a shaking speed of
180 rpm. Under the proposed optimized conditions, the amylase experimental yield (676.63 U mL−1) closely matched the yield (685.60 U mL−1) predicted by the statistical model. The optimization of the medium contributed to tenfold higher amylase production than
that of the control in shake-flask experiments. 相似文献
4.
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
5.
Jonny E. Scherwinski-Pereira Rodrigo S. da Guedes Paulo César P. FerminoJr Tatiane L. Silva Frederico Henrique S. Costa 《In vitro cellular & developmental biology. Plant》2010,46(4):378-385
An efficient procedure has been developed for inducing somatic embryogenesis and regeneration of plants from tissue cultures
of oil palm (Elaeis guineensis Jacq.). Thin transverse sections (thin cell layer explants) of different position in the shoot apex and leaf sheath of oil
palm were cultivated in Murashige and Skoog (MS) (Physiol Plant 15:473–497, 1962) medium supplemented with 0–450 μM picloram and 2,4-D with 3.0% sucrose, 500 mg L−1 glutamine, and 0.3 g L−1 activated charcoal and gelled with 2.5 g L−1 Phytagel. Embryogenic calluses were evaluated 12 wk after inoculation. Picloram (450 μM) was effective in inducing embryogenic
calluses in 41.5% of the basal explants. Embryogenic calluses were maintained on a maturation medium composed of basal media,
plus 0.6 μM NAA and 12.30 μM 2iP, 0.3 g L−1 activated charcoal, and 500 mg L−1 glutamine, with subcultures at 4-wk intervals. Somatic embryos were converted to plants on MS medium with macro- and micronutrients
at half-strength, 2% sucrose, and 1.0 g L−1 activated charcoal and gelled with 2.5 g L−1 Phytagel. 相似文献
6.
Fermentation of biomass derived synthesis gas to ethanol is a sustainable approach that can provide more usable energy and
environmental benefits than food-based biofuels. The effects of various medium components on ethanol production by Clostridium ragsdalei utilizing syngas components (CO:CO2) were investigated, and corn steep liquor (CSL) was used as an inexpensive nutrient source for ethanol production by C. ragsdalei. Elimination of Mg2+, NH4
+ and PO4
3− decreased ethanol production from 38 to 3.7, 23 and 5.93 mM, respectively. Eliminating Na+, Ca2+, and K+ or increasing Ca2+, Mg2+, K+, NH4
+ and PO4
3− concentrations had no effect on ethanol production. However, increased Na+ concentration (171 mM) inhibited growth and ethanol production. Yeast extract (0.5 g l−1) and trace metals were necessary for growth of C. ragsdalei. CSL alone did not support growth and ethanol production. Nutrients limiting in CSL were trace metals, NH4
+ and reducing agent (Cys: cysteine sulfide). Supplementation of trace metals, NH4
+ and CyS to CSL (20 g l−1, wet weight basis) yielded better growth and similar ethanol production as compared to control medium. Using 10 g l−1, the nutritional limitation led to reduced ethanol production. Higher concentrations of CSL (50 and 100 g l−1) were inhibitory for cell growth and ethanol production. The CSL could replace yeast extract, vitamins and minerals (excluding
NH4
+). The optimized CSL medium produced 120 and 50 mM of ethanol and acetate, respectively. The CSL could provide as an inexpensive
source of most of the nutrients required for the syngas fermentation, and thus could improve the economics of ethanol production
from biomass derived synthesis gas by C. ragsdalei. 相似文献
7.
Development of a cost-effective glucose-corn steep medium for production of butanol by Clostridium beijerinckii 总被引:1,自引:0,他引:1
M Parekh J Formanek H P Blaschek 《Journal of industrial microbiology & biotechnology》1998,21(4-5):187-191
Corn steep water (CSW) medium (1.6% solids plus 6% glucose) was evaluated for growth and butanol production by Clostridium beijerinckii NCIMB 8052 wild-type and hyper-amylolytic, hyper-butanol-producing mutant strain BA101. CSW alone was not a suitable substrate,
whereas addition of glucose supported growth and butanol production by both strains. In a batch-scale fermentation using an
optimized 6% glucose-1.6% solids CSW medium, C. beijerinckii NCIMB 8052 and strain BA101 produced 10.7 g L−1 and 14.5 g L−1 of butanol, respectively. The total solvents (acetone, butanol, and ethanol) produced by C. beijerinckii NCIMB 8052 and strain BA101 were 14 g L−1 and 20 g L−1, respectively. Initial fermentation in small-scale flasks containing 6% maltodextrin-1.6% solids concentration CSW medium
resulted in 6 g L−1 and 12.6 g L−1 of butanol production by C. beijerinckii NCIMB 8052 and strain BA101, respectively. CSW can serve as an economic source of nitrogen, vitamins, amino acids, minerals,
and other nutrients. Thus, it is feasible to use 6% glucose-1.6% solids CSW medium in place of semi-defined P2 medium.
Received 9 February 1998/ Accepted in revised form 1 September 1998 相似文献
8.
Based on the report that the introduction of the biosynthetic precursor of lincomycin, propylproline, could increase the production
of lincomycin (Bruce et al. in US Patent 3,753,859, 1973), a mutant strain pro10–20, with resistance of feedback suppression of proline (an analog of propylproline) was thus selected
and lincomycin production increased by 10%. The addition of three amino acids (l-proline, l-tyrosine, l-alanine) which are the precursors of propylproline to the fermentation medium was found to enhance the accumulation of l-dopa through different pathways and was favorable to lincomycin biosynthesis. The production of lincomycin was increased
by 23, 10, 13%, respectively, with the addition of 0.05 g L−1
l-proline at 60 h, 0.005 g L−1
l-tyrosine and 0.1 g L−1
l-alanine directly in the medium. 相似文献
9.
Lactobacillus intermedius NRRL B-3693 produced mannitol, lactic acid, and acetic acid when grown on fructose at 37°C. The optimal pH for mannitol production
from fructose by the heterofermentative lactic acid bacterium (LAB) in pH-controlled fermentation was at pH 5.0. It produced
160.7 ± 1.1 g mannitol in 40 h with a volumetric productivity of 4.0 g l−1 h−1 in a simplified medium containing 250 g fructose, 50 g corn steep liquor (CSL), and 33 mg MnSO4 per liter. However, the mannitol production by the LAB was severely affected by the variability of CSL. The supplementation
of CSL with soy peptone (5 g/l), tryptophan (50 mg/l), tryptophan (50 mg/l) plus tyrosine (50 mg/l), or commercial protease
preparation (2 ml/100 g of CSL) enhanced the performance of the inferior CSL and thus helped to overcome the nutrient limitations. 相似文献
10.
M. Bustamante M. E. González A. Cartes M. C. Diez 《Journal of industrial microbiology & biotechnology》2011,38(1):189-197
The present work optimized the initial pH of the medium and the incubation temperature for ligninolytic enzymes produced by
the white-rot fungus Anthracophyllum discolor. Additionally, the effect of soya lecithin on mycelial growth and the production of ligninolytic enzymes in static batch
cultures were evaluated. The critical micelle concentration of soya lecithin was also studied by conductivity. The effects
of the initial pH (3, 4, and 5) and incubation temperature (20, 25, and 30°C) on different enzymatic activities revealed that
the optimum conditions to maximize ligninolytic activity were 26°C and pH 5.5 for laccase and manganese peroxidase (MnP) and
30°C and pH 5.5 for manganese-independent peroxidase (MiP). Under these culture conditions, the maximum enzyme production
was 10.16, 484.46, and 112.50 U L−1 for laccase, MnP, and manganese-independent peroxidase MiP, respectively. During the study of the effect of soya lecithin
on A. discolor, we found that the increase in soya lecithin concentration from 0 to 10 g L−1 caused an increase in mycelial growth. On the other hand, in the presence of soya lecithin, A. discolor produced mainly MnP, which reached a maximum concentration of 30.64 ± 4.61 U L−1 after 25 days of incubation with 1 g L−1 of the surfactant. The other enzymes were produced but to a lesser extent. The enzymatic activity of A. discolor was decreased when Tween 80 was used as a surfactant. The critical micelle concentration of soya lecithin calculated in our
study was 0.61 g L−1. 相似文献
11.
Chen XS Li S Liao LJ Ren XD Li F Tang L Zhang JH Mao ZG 《Bioprocess and biosystems engineering》2011,34(5):561-567
The production of ε-poly-l-lysine (ε-PL) by Streptomyces sp. M-Z18 from glycerol was investigated in a 5-L jar-fermenter. Batch fermentations by Streptomyces sp. M-Z18 at various pH values ranging from 3.5 to 4.5 were studied. Based on the analysis of the time course of specific
cell growth rate and specific ε-PL formation rate, a novel two-stage pH control strategy was developed to improve ε-PL production
by shifting the culture pH from 3.5 to 3.8 after 36 h of cultivation. By applying the strategy, the maximal ε-PL concentration
and productivity had a significant improvement and reached 9.13 g L−1 and 4.76 g L−1 day−1, respectively, compared with those in one-stage pH control process where the pH value is controlled at 3.5 (7.83 g L−1 and 3.13 g L−1 day−1). Fed-batch fermentation with two-stage pH control strategy was also applied to produce ε-PL; final ε-PL concentration of
30.11 g L−1 was obtained, being 3.3-fold greater than that of batch fermentation. To our knowledge, it is the first report on production
of ε-PL from glycerol in fermenter scale and achievement of high ε-PL production with two-stage pH control strategy. 相似文献
12.
Clemens G. Borkenstein Josef Knoblechner Heike Frühwirth Michael Schagerl 《Journal of applied phycology》2011,23(1):131-135
The present study reviews the options of cultivating the green alga, Chlorella emersonii, under photoautotrophic conditions with flue gas derived from a cement plant. It was conducted in the Lafarge Perlmooser
plant in Retznei, Austria, where stone coal and various surrogate fuels such as used tyres, plastics and meat-and-bone meal
are incinerated for heating limestone. During 30 days of cultivation, flue gas had no visible adverse effects compared to
the controls grown with pure CO2. The semi-continuous cultivation with media recycling was performed in 5.5-L pH-stat photobioreactors. The essay using CO2 from flue gas yielded a total of 2.00 g L−1 microalgal dry mass and a CO2 fixation of 3.25 g L−1. In the control, a total of 2.06 g L−1 dry mass was produced and 3.38 g L−1 CO2 was fixed. Mean growth rates were between 0.10 day−1 (control) and 0.13 day−1 (flue gas). No accumulation of flue gas residues was detected in the culture medium. At the end of the experiment, however,
the concentration of lead was three times higher in algal biomass compared to the control, indicating that cultures aerated
with this type of flue gas should not be used as food supplements or animal feed. 相似文献
13.
Survase SA Jurgens G van Heiningen A Granström T 《Applied microbiology and biotechnology》2011,91(5):1305-1313
Clostridium beijerinckii DSM 6423 was studied using different continuous production methods to give maximum and stable production of isopropanol and
n-butanol. In a single-stage continuous culture, when wood pulp was added as a cell holding material, we could increase the
solvent productivity from 0.47 to 5.52 g L−1 h−1 with the yield of 54% from glucose. The overall solvent concentration of 7.51 g L−1 (39.4% isopropanol and 60.6% n-butanol) with the maximum solvent productivity of 0.84 g L−1 h−1 was obtained with two-stage continuous culture. We were able to run the process for more than 48 overall retention times
without losing the ability to produce solvents. 相似文献
14.
Bettin F Montanari Q Calloni R Gaio TA Silveira MM Dillon AJ 《Journal of industrial microbiology & biotechnology》2009,36(1):1-9
Some conditions in media composition for laccases production, such as different sources of carbon and organic nitrogen, antifoams
and a surfactant, were studied in liquid cultures of Pleurotus sajor-caju strain PS-2001. Cultivation with fructose or glucose as carbon sources produced maximum enzyme activities of 37 and 36 U mL−1, respectively. When sucrose was present in the medium, the best results were obtained using 5 g L−1 of this carbohydrate, on the 11th day of the process, attaining laccase titres of 13 U mL−1. In a medium without casein, practically no enzyme was produced during the experiments; among the sources of nitrogen studied,
pure casein led to the highest titres of laccase activity. Different concentrations of pure casein and sucrose were also tested.
As to the different concentrations of casein, the addition of 1.5 g L−1 resulted in the highest titres of laccase activity. Negligible levels of manganese peroxidase activity were also detected
in the culture medium. In low concentrations, polypropylene glycol or silicon-based antifoams and the surfactant Tween 80
have no significant influence on the formation of laccases by P. sajor-caju. However, enhanced concentration of polypropylene glycol negatively affected the production of laccases but favored the titres
in total peroxidases, lignin peroxidase and veratryl alcohol oxidase. 相似文献
15.
This work was aimed at producing inulinase by solid-state fermentation of sugarcane bagasse, using factorial design to identify
the effect of corn steep liquor (CSL) and soybean bran concentration, particle size of bagasse and size of inoculum. Maximum
inulinase activity achieved was 250 U per g of dry substrate (gds) at 20% (w/w) of CSL, 5% (w/w) of soybean bran, 1 × 1010 cells mL−1 and particle size of bagasse in the range 9/32 mesh. The use of soybean bran decreased the time to reach maximum activity
from 96 to 24 h and the maximum productivity achieved was 8.87 U gds−1 h−1. The maximum activity was obtained at pH 5.0 and 55.0°C. Within the investigated range, the enzyme extract was more thermostable
at 50.0°C, showing a D-value of 123.1 h and deactivation energy of 343.9 kJ gmol−1. The extract showed highest stability from pH 4.5 to 4.8. Apparent K
m and V
max are 7.1 mM and 17.79 M min−1, respectively. 相似文献
16.
The maximum ethanol concentration produced from glucose in defined media at 45°C by the thermotolerant yeast Kluyveromyces marxianus IMB3 was 44 g L−1. Acclimatisation of the strain through continuous culture at ethanol concentrations up to 80 g L−1, shifted the maximum ethanol concentration at which growth was observed from 40 g L−1 to 70 g L−1. Four isolates were selected from the continuous culture, only one of which produced a significant increase in final ethanol
concentration (50 ± 0.4 g L−1), however in subsequent fermentations, following storage on nutrient agar plates, the maximum ethanol concentration was comparable
with the original isolate. The maximum specific ethanol production rates (approximately 1.5 g (gh)−1) were also comparable with the original strain except for one isolate (0.7 g (gh)−1). The specific ethanol productivity decreased with ethanol concentration; this decrease correlated linearly (rval 0.92) with
cell viability. Due to the transience of induced ethanol tolerance in the strain it was concluded that this was not a valid
method for improving final ethanol concentrations or production rates.
Received 18 July 1997/ Accepted in revised form 19 February 1998 相似文献
17.
Fontes CP Honorato TL Rabelo MC Rodrigues S 《Bioprocess and biosystems engineering》2009,32(4):493-499
The use of agriculture excess as substrate in industrial fermentations became an interesting alternative to reduce production
costs and to reduce negative environmental impact caused by the disposal of these products. In this work, a kinetic study
of mannitol production using cashew apple juice as substrate was studied. The carbohydrates of cashew apple juice are glucose
and fructose. Sucrose addition favored the yield of mannitol (85%) at the expense of lower productivity. The best results
were obtained applying only cashew apple juice as substrate, containing 50 g L−1 of total reducing sugar (28 g L−1 of fructose), yielding 18 g L−1 of mannitol with 67% of fructose conversion into mannitol and productivity of 1.8 g L−1 h−1. 相似文献
18.
Candida peltata NRRL Y-6888 to ferment xylose to xylitol was evaluated under different fermentation conditions such as pH, temperature, aeration,
substrate concentration and in the presence of glucose, arabinose, ethanol, methanol and organic acids. Maximum xylitol yield
of 0.56 g g−1 xylose was obtained when the yeast was cultivated at pH 6.0, 28°C and 200 rpm on 50 g L−1 xylose. The yeast produced ethanol (0.41 g g−1 in 40 h) from glucose (50 g L−1) and arabitol (0.55 g g−1 in 87 h) from arabinose (50 g L−1). It preferentially utilized glucose > xylose > arabinose from mixed substrates. Glucose (10 g L−1), ethanol (7.5 g L−1) and acetate (5 g L−1) inhibited xylitol production by 61, 84 and 68%, respectively. Arabinose (10 g L−1) had no inhibitory effect on xylitol production.
Received 24 December 1998/ Accepted in revised form 18 March 1999 相似文献
19.
Withanolides are biologically active secondary metabolites present in roots and leaves of Withania somnifera. In the present study, we have induced adventitious roots from leaf explants of W. somnifera for the production of withanolide-A, which is having pharmacological activities. Adventitious roots were induced directly
from leaf segments of W. somnifera on half strength Murashige and Skoog (MS) semisolid medium (0.8% agar) with 0.5 mg l−1 indole-3-butyric acid (IBA) and 30 g l−1 sucrose. Adventitious roots cultured in flasks using half strength MS liquid medium with 0.5 mg l−1 IBA and 30 g l−1 showed higher accumulation of biomass (108.48 g l−1FW and 10.76 g l−1 DW) and withanolide-A content (8.8 ± 0.20 mg g−1 DW) within five weeks. Nearly 11-fold increment of fresh biomass was evident in suspension cultures and adventitious root
biomass produced in suspension cultures possessed 21-fold higher withanolide-A content when compared with the leaves of natural
plants. An inoculum size of 10 g l−1 FW favoured the biomass accumulation and withanolide-A production in the tested range of 2.5, 5.0, 10.0 and 20.0 g l−1 FW. Among different media tested [Murashige and Skoog (MS), Gamborg’s (B5), Nitsch and Nitsch (NN) and Chu’s (N6)], MS medium
favoured both biomass accumulation and withanolide-A production. Half strength MS medium favoured the biomass accumulation
and withanolide-A production among the different strength MS medium tested (0.25, 0.5, 0.75, 1.0, 1.5 and 2.0). The current
results showed great potentiality of adventitious roots cultures for the production of withanolide-A. 相似文献
20.
I-Y Lee W T Seo G J Kim M K Kim C S Park Y H Park 《Journal of industrial microbiology & biotechnology》1997,18(4):255-259
Maltose and sucrose were efficient carbon sources for the production of curdlan by a strain of Agrobacterium sp. A two-step, fed-batch operation was designed in which biomass was first produced, followed by curdlan production which
was stimulated by nitrogen limitation. There exists an optimal timing for nitrogen limitation for curdlan production in the
two-step, fed-batch operation. Maximum curdlan production (60 g L−1) was obtained from sucrose with a productivity of 0.2 g L−1 h−1 when nitrogen was limited at a cell concentration of 16.0 g L−1. It was also noted that the curdlan yield from sucrose was as high as 0.45 g curdlan g−1 sucrose, and the highest specific production rate was 1.0 g curdlan g−1 cells h−1 right after nitrogen limitation. Of particular importance was the use of molasses as a cheap carbon source to produce curdlan
in the two-step, fed-batch cultivation. As high as 42 g L−1 of curdlan with a yield of 0.35 g curdlan g−1 total sugar was obtained after 120 h of fed-batch cultivation.
Received 20 August 1996/ Accepted in revised form 26 November 1996 相似文献