共查询到20条相似文献,搜索用时 15 毫秒
1.
Selective production of bikaverin in a fluidized bioreactor with immobilized Gibberella fujikuroi 总被引:1,自引:0,他引:1
Escamilla-Silva Eleazar Poggi-Varaldo Héctor De la Torre-Martínez M. Mayra Sanchez Cornejo M.A. Guadalupe Dendooven Luc 《World journal of microbiology & biotechnology》2001,17(5):469-474
The best culture medium composition for the production of bikaverin by Gibberella fujikuroi in shake-flasks, i.e. 100 g glucose l–1; 1 g NH4Cl l–1; 2 g rice flour l–1; 5 g KH2PO4 l–1 and 2.5 g MgSO4 l–1, was obtained through a fractional factorial design and then scaled-up to a fluidized bioreactor. The effects of carbon and nitrogen concentrations, inoculum size, aeration, flow rate and bead sizes on batch bikaverin production using immobilized G. fujikuroi in a fluidized bioreactor were determined by an orthogonal experimental design. Concentrations of up to 6.83 g bikaverin l–1 were obtained when the medium contained 100 g glucose l–1 and 1 g NH4Cl l–1 with an inoculum ratio of 10% v/v, an aeration rate of 3 volumes of air per volume of medium min–1, and a bead size of 3 mm. Based on dry weight, the bikaverin production was 30–100 times larger than found in submerged culture and approximately three times larger than reported for solid substrate fermentation. 相似文献
2.
An efficient and reproducible protocol is described for the regeneration of Cinnamomum camphora protoplasts isolated from cultured embryogenic suspension cells. Maximum protoplast yield (13.1±2.1×106/g FW) and viability (91.8±3.8%) were achieved using a mixture of 3% (w/v) cellulase Onozuka R10 and 3% (w/v) macerozyme Onozuka R10 in 12.7% (w/v) mannitol solution containing 0.12% (w/v) MES, 0.36% (w/v) CaCl2·2H2O, and 0.011% (w/v) NaH2PO4·2H2O. First divisions occurred 7–10 days following culture initiation. The highest division frequency (24.6±2.9%) and plating efficiency (6.88±0.8%) were obtained in liquid medium (MS) supplemented with 30 g l–1 sucrose, 0.7M glucose, 0.1 mg l–1 NAA, 1.0 mg l–1 BA, and 1.0 mg l–1 GA3. After somatic embryo induction and then shoot induction, the protoplast-derived embryos produced plantlets at an efficiency of 17.5%. Somatic embryos developed into well-rooted plants on MS medium supplemented with 1.0 mg l–1 3-indole butyric acid (IBA). Regenerated plants that transferred to soil have normal morphology. 相似文献
3.
By-product formation by a novel glycerol-producing yeast,Candida glycerinogenes,with different O2 supplies 总被引:3,自引:0,他引:3
Candida glycerinogenes is an aerobe which does not depend on sulphite for production of glycerol. With a sufficient O2 supply, up to 130 g glycerol l–1 was produced with 2.6 g acetic acid l–1 as by-product. However, with an insufficient O2 supply – with higher volumes of medium or at higher corn steep liquid concentrations – the glycerol concentration was lower because the by-products, ethanol, pyruvate and lactic acid, were produced in greater amounts, up to 45 g l–1, 4.3 g l–1, 1.6 g l–1, respectively, whereas, less acetic acid (0.6 g l–1) was produced. In addition, ethanol decreased to 0.4 g l–1 and the glycerol yield improved from 34 to 50% (w/w) by adding 50 g sulphite l–1, nevertheless, acetic acid increased to 7.8 g l–1. 相似文献
4.
Lactulose production from lactose and fructose was investigated with several commercial -galactosidases. The enzyme from Kluyveromyces lactis exhibited the highest lactulose productivity among the -galactosidases tested. The reaction conditions for lactulose production were optimized using cells that had been permeabilized by treatment with 50% (v/v) ethanol: cell concentration, 10.4 g l–1; concentration of substrates, 40% (w/v) lactose and 20% (w/v) fructose; temperature, 60°C; pH 7.0. Under these conditions, the permeabilized cells produced approximately 20 g l–1 lactulose in 3 h with a lactulose productivity of 6.8 g l–1 h–1. These results represent 1.3- and 2.1-fold increases in lactulose concentration and productivity compared with untreated washed cells. This is the first reported trial of enzymatic synthesis of lactulose using permeabilized yeast cells. 相似文献
5.
Hyung-Kyoon Choi Sang-Ic Kim Joo-Sun Son Seung-Suh Hong Hyun-Soo Lee In-Sik Chung Hyong-Joo Lee 《Biotechnology letters》2000,22(22):1793-1796
High paclitaxel production (26 mg l–1) was achieved through the intermittent feeding of 3, 1, and 2% (w/v) sucrose at days 0, 7, and 21, respectively, to a suspension culture of Taxus chinensis cells. Intermittent feedings of 1 and 2% (w/v) maltose at days 7 and 21, respectively, to the culture increased the paclitaxel production up to 67 mg l–1. 相似文献
6.
Genta Kobayashi Kuniaki Tanaka Hirokazu Itoh Takeharu Tsuge Kenji Sonomoto Ayaaki Ishizaki 《Biotechnology letters》2000,22(13):1067-1069
The feeding of propionic acid for production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] by Alcaligenes eutrophus ATCC17697 was optimized using a fed-batch culture system. The concentration of propionic acid was maintained at 3 g l–1 as growth was inhibited by propionic acid in the broth. A pH-stat substrate feeding system was used in which propionic acid was fed automatically to maintain a pH of the culture broth at 7.0. By feeding a substrate solution containing 20% (w/v) propionic acid, 4.9% (w/v) ammonia water [at a molar ratio of carbon to nitrogen (C/N molar ratio) of 10] in cell growth phase, the concentration of propionic acid in the broth was maintained at 3 g l–1 giving a specific growth rate of 0.4 h–1. To promote P(3HB-co-3HV) production, two stage fed-batch culture which consisted of the stage for the cell growth and the stage for the P(3HB-co-3HV) accumulation was carried out. When the substrate solution whose C/N molar ratio was 50 was fed in P(3HB-co-3HV) accumulation phase, the cell concentration and the P(3HB-co-3HV) content in the cells reached 64 g l–1 and 58% (w/w) in 55.5 h, respectively. 相似文献
7.
Cintia Marangoni Agenor Furigo Jr. Gláucia Maria Falcão de Aragão 《Biotechnology letters》2000,22(20):1635-1638
With the objective of verifying the influence of oleic acid as a nutritional supplement in the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by Ralstonia eutropha, cultures were established with 0.3 g oleic acid l–1 and without this supplement, in 30 g inverted sugar l–1 and 1 g propionic acid l–1. The use of this supplement increased the accumulation of polymer from 18.3% to 28.3% (w/w) although the mass of 3-hydroxyvalerate in the polymer remained constant for both cultures. 相似文献
8.
Mathematical model parameters for the methanogenic degradation of propylene glycol were estimated in a sequential manner by means of an optimization technique. Model parameters determined from an initial experimental data set using one bioreactor were then verified with the results from a second bioreactor. The proposed methodology is a useful tool to obtain model parameters for continuous flow reactors with completely mixed regime.
Abbrevations:
S – substrate concentration (mg COD l–1); S
in – influent substrate concentration (mg COD l–1); D
L – dilution rate (day–1); – stoichiometric coefficients (ND); nx – number of microbial species (ND); X
S – fixed biomass concentration (mg biomass l–1); X
L – suspended biomass concentration of (mg biomass l–1); k
d – decay rate of biomass (day–1); b
S – specific detachment rate of biofilm (day–1); – specific growth rate of biomass (day–1); m – maximum specific growth rate of biomass (day–1); K
S – half saturation constant (mg COD l–1); K
I – inhibition constant (mg COD l–1). 相似文献
9.
The microalga Haematococcus pluvialis was cultured with NaNO3 from 0 to 1 g l–1 and optimal growth was obtained at 0.15 g l–1. Sodium acetate and malonate (from 0 to 2% w/v) enhanced the accumulation of astaxanthin three and five times higher, respectively, than in autotrophic control cultures. However, high concentration of those compounds strongly inhibited growth. The ratio chlorophyll a/total carotenoids was a good indicator of the extent of nitrogen deficiency in the cells. 相似文献
10.
Murashige & Skoog medium was modified for enhancing artemisinin production in Artemisia annua hairy root cultures by altering the ratio of NO
3
–
/NH
4
+
and the total amount of initial nitrogen. Increasing ammonium to 60 mM decreased both growth and artemisinin accumulation in hairy root cultures. With NO
3
–
/NH
4
+
at 5:1 (w/w), the optimum concentration of total initial nitrogen for artemisinin production was 20 mM. After 24 days of cultivation with 16.7 mM nitrate and 3.3 mM ammonium, the maximum artemisinin production of hairy roots was about 14 mg l–1, a 57% increase over that in the standard MS medium. 相似文献
11.
Acid hydrolysis of sugarcane bagasse for lactic acid production 总被引:3,自引:0,他引:3
Pattana Laopaiboon Arthit Thani Vichean Leelavatcharamas Lakkana Laopaiboon 《Bioresource technology》2010,101(3):1036-1043
In order to use sugarcane bagasse as a substrate for lactic acid production, optimum conditions for acid hydrolysis of the bagasse were investigated. After lignin extraction, the conditions were varied in terms of hydrochloric (HCl) or sulfuric (H2SO4) concentration (0.5–5%, v/v), reaction time (1–5 h) and incubation temperature (90–120 °C). The maximum catalytic efficiency (E) was 10.85 under the conditions of 0.5% of HCl at 100 °C for 5 h, which the main components (in g l−1) in the hydrolysate were glucose, 1.50; xylose, 22.59; arabinose, 1.29; acetic acid, 0.15 and furfural, 1.19. To increase yield of lactic acid production from the hydrolysate by Lactococcus lactis IO-1, the hydrolysate was detoxified through amberlite and supplemented with 7 g l−1 of xylose and 7 g l−1 of yeast extract. The main products (in g l−1) of the fermentation were lactic acid, 10.85; acetic acid, 7.87; formic acid, 6.04 and ethanol, 5.24. 相似文献
12.
Urbance SE Pometto AL Dispirito AA Denli Y 《Applied microbiology and biotechnology》2004,65(6):664-670
Continuous and repeat-batch biofilm fermentations using Actinobacillus succinogenes were performed with immobilized and suspended-cell systems. For the immobilized continuous system, plastic composite supports (PCS) containing 50% (w/w) polypropylene (PP), 35% (w/w) ground soybean hulls, 5% (w/w) dried bovine albumin, 2.5% (w/w) soybean flour, 2.5% (w/w) yeast extract, 2.5% (w/w) dried red blood cells, and 2.5% (w/w) peptone, or PP tubes (8.5 cm in length) were arranged around the agitator shaft in a grid formation. Agitation was controlled at 125 rpm and 150 rpm. Samples were taken at dilution rates of 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 h–1 and analyzed for succinic acid production and glucose consumption (g l–1). For PCS bioreactors, the highest final succinic acid concentrations (10.1 g –1, 10.4 g l–1) and percentage yields (62.6%, 71.6%) occurred at the dilution rate of 0.2 h–1. PCS disks were evaluated in a repeat-batch biofilm reactor. Suspended-cell batch fermentations were performed in flasks and a repeat-batch bioreactor. The maximum concentration of succinic acid produced was 40 g l–1. Peak succinic acid percentage yields in continuous and repeat-batch fermentations of A. succinogenes were observed in suspended-cell continuous fermentations at a dilution rate of 1.0 h–1 (76.2%) and in PCS repeat-batch fermentations with an initial glucose concentration of 40 g l–1 (86.7%). 相似文献
13.
Wen Chang Chen 《Biotechnology letters》1996,18(1):69-72
Summary Effect of initial sucrose concentration on the production of -fructofuranosidase from Aspergillus japonicus TIT-90076 were investigated in shaking batch cultures. The maximal enzyme production occurred at 25 % (w/v) sucrose and an inhibitory effect on cell growth was exhibited when the initial sucrose concentration was above 10 % (w/v). For evaluation of the process economy, a relationship between the process output (FFase production at 96-h cultivation, in units ml–1) and the process input (initial sucrose concentration, S0, in % (w/v)) can be simply expressed as follows: FFase production = (142.9S0/(29.3 + S0))(16.7 – 0.22S0). 相似文献
14.
Enzymatic pre-hydrolysis applied to the anaerobic treatment of effluents from poultry slaughterhouses 总被引:1,自引:0,他引:1
Alessandra Bormann Garcia Vallado Denise Maria Guimares Freire Magali Christe Cammarota 《International biodeterioration & biodegradation》2007,60(4):219-225
A pool of hydrolases with 21.4 U g−1 lipase activity was produced through solid-state fermentation of the fungus Penicillium restrictum in waste from the Orbignya oleifera (babassu) oil processing industry. Enzymatic hydrolysis and anaerobic biodegradability tests were conducted on poultry slaughterhouse effluents with varying oil and grease contents (150–1200 mg l−1) and solid enzymatic pool concentrations (0.1–1.0% w/v). Enhanced anaerobic treatment efficiency relative to raw effluent was achieved when a 0.1% concentration of enzymatic pool was used in the pre-hydrolysis stage with 1200 mg oil and grease l−1 (chemical oxygen demand (COD) removal efficiency of 85% vs. 53% and biogas production of 175 ml vs. 37 ml after 4 d). 相似文献
15.
Dairy wastewater containing different oil and grease contents was treated in batch activated sludge systems with and without (control) an enzymatic pre-hydrolysis stage [with 0.2% (w/v) of fermented babassu cake containing Penicillium restrictum lipases]. When the oil and grease concentration in the control bioreactor was increased (400, 600 and 800 mg l–1), the COD removal efficiency fell (86%, 75% and 0%). However, in the reactor fed with pre-hydrolysed wastewater, COD removal efficiency was maintained (93%, 92% and 82%). At an oil and grease concentration of 800 mg l–1, the control bioreactor presented final volatile suspended solids (VSS) values ten times greater (2225 mg l–1) than those obtained for bioreactor fed with pre-hydrolysed wastewater (200 mg l–1). 相似文献
16.
Massimiliano Fenice Federico Federici Laura Selbmann Maurizio Petruccioli 《Journal of biotechnology》2000,80(3)
Extracellular pigment production by immobilised Monascus purpureus C322 has been studied in repeated-batch processes using different immobilising carriers such as Ca-alginate, polyurethane sponge, active carbon and pearlite. With Ca-alginate, pigment production was maximum (30.5 UA470 as process mean production, three batches) while the cell leakage was negligible (0.4 g l−1 free biomass) and the bead mechanical stability good; with this carrier, an extended repeated-batch fermentation (nine batches, 55 days) was carried out: the process pigment productivity was 3.87 UA470 day−1. 相似文献
17.
Ram horns are a waste material from the meat industry. The use of ram horn peptone (RHP) as a supplement for lactic acid production was investigated using Lactobacillus casei. For this purpose, first, RHP was produced. Ram horns were hydrolysed by treating with acids (3 M H2SO4 and 6 M HCl) and neutralizing the solutions to yield ram horn hydrolysate (RHH). The RHH was evaporated to yield RHP. The amounts of protein, nitrogen, ash, some minerals, total sugars, total lipids and amino acids of the RHP were determined and compared with a bacto-tryptone from casein. When the concentrations (1–6% w/v) of the RHP were used in bacterial growth medium as a supplement, 2% RHP (ram horn peptone medium) had a maximum influence on the production of lactic acid by L. casei. The content of lactic acid in the culture broth containing 2% RHP (43 g l–1) grown for 24 h was 30% higher than that of the control culture broth (33 g l–1) and 10% higher than that of 2% bacto-tryptone (39 g l–1). RHP was demonstrated to be a suitable supplement for production of lactic acid. This RHP may prove to be a valuable supplement in fermentation technology. 相似文献
18.
Inhibition of yeast by lactic acid bacteria in continuous culture: nutrient depletion and/or acid toxicity? 总被引:1,自引:0,他引:1
Lactic acid was added to batch very high gravity (VHG) fermentations and to continuous VHG fermentations equilibrated to steady state with Saccharomyces cerevisiae. A 53% reduction in colony-forming units (CFU) ml–1 of S. cerevisiae was observed in continuous fermentation at an undissociated lactic acid concentration of 3.44% w/v; and greater than 99.9% reduction was evident at 5.35% w/v lactic acid. The differences in yeast cell number in these fermentations were not due to pH, since batch fermentations over a pH range of 2.5–5.0 did not lead to changes in growth rate. Similar fermentations performed in batch showed that growth inhibition with added lactic acid was nearly identical. This indicates that the apparent high resistance of S. cerevisiae to lactic acid in continuous VHG fermentations is not a function of culture mode. Although the total amount of ethanol decreased from 48.7 g l–1 to 14.5 g l–1 when 4.74% w/v undissociated lactic acid was added, the specific ethanol productivity increased ca. 3.2-fold (from 7.42×10–7 g to 24.0×10–7 g ethanol CFU–1 h–1), which indicated that lactic acid stress improved the ethanol production of each surviving cell. In multistage continuous fermentations, lactic acid was not responsible for the 83% (CFU ml–1) reduction in viable S. cerevisiae yeasts when Lactobacillus paracasei was introduced to the system at a controlled pH of 6.0. The competition for trace nutrients in those fermentations and not lactic acid produced by L. paracasei likely caused the yeast inhibition. 相似文献
19.
Jeong-Hwa Kim Mi-Ryung Kim Ji-Hyun Lee Jin-Woo Lee Sung-Koo Kim 《Biotechnology letters》2000,22(12):987-990
Pullulan productivity was optimized in Aureobasidium pullulans ATCC 42023 with 54 g glucose l–1. Pullulan with its higher molecular weight (>1000000) was produced using 2% (w/v) glucose and 3% (w/v) glucosamine together. The maximum concentration of pullulan was 8 g l–1 at 140 h with shake-flask culture. 相似文献
20.
S. N. Mukhopadhyay A. Ornelas Vale E. Camargo Rubio G. Cassarubias Arcos 《Applied microbiology and biotechnology》1978,6(1):55-66
Summary Submerged batch cultivation under controlled environmental conditions of pH 3.8, temperature 30°C, and KLa200 h–1 (above 180 mMO2
l
–1 h–1 oxygen supply rate) produced a maximum (12.0 g·l
–1) SCP (Candida utilis) yield on the deseeded nopal fruit juice medium containing C/N ratio of 7.0 (initial sugar concentration 25 g·l
–1) with a yield coefficient of 0.52 g cells/g sugar. In continuous cultivation, 19.9 g·l
–1 cell mass could be obtained at a dilution rate (D) of 0.36 h–1 under identical environmental conditions, showing a productivity of 7.2 g·l
–1·h–1. This corresponded to a gain of 9.0 in productivity in continuous culture over batch culture. Starting with steady state values of state variables, cell mass (CX–19.9 g·l
–1), limiting nutrient concentration (Cln–2.5 g·l
–1) and sugar concentration (CS–1.5 g·l
–1) at control variable conditions of pH 3.8, 30°C, and KLa 200 h–1 keeping D=0.36 h–1 as reference, transient response studies by step changes of these control variables also showed that this pH, temperature and KLa conditions are most suitable for SCP cultivation on nopal fruit juice. Kinetic equations obtained from experimental data were analysed and kinetic parameters determined graphically. Results of SCP production from nopal fruit juice are described.Nomenclature Cln
concentration of ammonium sulfate (g·l
–1)
- CS
concentration of total sugar (g·l
–1)
- CX
cell concentration (g·l
–1)
- D
dilution rate (h–1)
- Kln
Monod's constant (g·l
–1)
- m
maintenance coefficient (g ammonium sulfate cell–1 h–1)
- m(S)
maintenance coefficient (g sugar g cell–1 h–1)
- t
time, h
- Y
yield coefficient (g cells/g ammonium sulfate)
- Ym
maximum of Y
- YS
yield coefficient based on sugar consumed (g cells · g sugar–1)
- YS(m)
maximum value of YS
-
µm
maximum specific growth rate constant (h–1) 相似文献