共查询到20条相似文献,搜索用时 31 毫秒
1.
Yun-He Li Yong-Jie Wu Bei Wu Ming-Hong Zou Zhi Zhang Guang-Ming Sun 《Acta Physiologiae Plantarum》2011,33(5):1715-1722
In mainland China, the most popular pineapple cultivar is ‘Comte de Paris’. Gibberellic acids have been widely applied to
enhance fruit growth in various species. To evaluate the effect of gibberellic acid (GA3) on ‘Comte de Paris’ pineapple production and quality, pineapple fruits were sprayed with GA3 at concentrations of 5, 20, 50, or 100 mg l−1 at both 0 and 15 days after flowering (DAF). Fruits were sampled every 15 days from 0 to 60 DAF (maturation) for flow cytometric
analysis and histological observation. The results showed that the treatments with the three highest concentrations of GA3 significantly increased fruit weight, and the most effective concentration was 50 mg l−1 GA3, which increased the flesh weight by 20.3% compared to the control. Although treatment with GA3 had little effect on the total soluble solids and fruit juice pH, it increased the vitamin C content. Although flow cytometric
analysis showed that the 50 mg l−1 GA3 treatment had only a slight impact on the number of S phase cells, histological observations indicated that the increase
of fruit volume and flesh weight under this GA3 treatment was not due to the increase of cell number but a result of the increase of cell area in the fruit flesh. 相似文献
2.
Luo LH Seo JW Baek JO Oh BR Heo SY Hong WK Kim DH Kim CH 《Applied microbiology and biotechnology》2011,89(3):697-703
Although the de novo biosynthetic mechanism of 3-hydroxypropionic acid (3-HP) in glycerol-fermenting microorganisms is still
unclear, the propanediol utilization protein (PduP) of Lactobacillus species has been suggested to be a key enzyme in this regard. To verify this hypothesis, a pduP gene from Lactobacillus reuteri was cloned and expressed, and the encoded protein was characterized. Recombinant L. reuteri PduP exhibited broad substrate specificity including 3-hydroxypropionaldehyde and utilized both NAD+ and NADP+ as a cofactor. Among various aldehyde substrates tested, the specific activity was highest for propionaldehyde, at pH 7.8
and 37 °C. The K
m and V
max values for propionaldehyde in the presence of NAD+ were 1.18 mM and 0.35 U mg−1, respectively. When L. reuteri pduP was overexpressed in Klebsiella pneumoniae, 3-HP production remarkably increased as compared to the wild-type strain (from 0.18 g L−1 to 0.72 g L−1) under shake-flask culture conditions, and the highest titer (1.38 g L−1 3-HP) was produced by the recombinant strain under batch fermentation conditions in a bioreactor. This is the first report
stating the enzymatic properties of PduP protein and the probable role in biosynthesis of 3-HP in glycerol fermentation. 相似文献
3.
Production of hexanoic acid from d-galactitol by a newly isolated Clostridium sp. BS-1 总被引:1,自引:0,他引:1
Byoung Seung Jeon Byung-Chun Kim Youngsoon Um Byoung-In Sang 《Applied microbiology and biotechnology》2010,88(5):1161-1167
In a study screening anaerobic microbes utilizing d-galactitol as a fermentable carbon source, four bacterial strains were isolated from an enrichment culture producing H2, ethanol, butanol, acetic acid, butyric acid, and hexanoic acid. Among these isolates, strain BS-1 produced hexanoic acid
as a major metabolic product of anaerobic fermentation with d-galactitol. Strain BS-1 belonged to the genus Clostridium based on phylogenetic analysis using 16S rRNA gene sequences, and the most closely related strain was Clostridium sporosphaeroides DSM 1294T, with 94.4% 16S rRNA gene similarity. In batch cultures, Clostridium sp. BS-1 produced 550 ± 31 mL L−1 of H2, 0.36 ± 0.01 g L−1 of acetic acid, 0.44 ± 0.01 g L−1 of butyric acid, and 0.98 ± 0.03 g L−1 of hexanoic acid in a 4-day cultivation. The production of hexanoic acid increased to 1.22 and 1.73 g L−1 with the addition of 1.5 g L−1 of sodium acetate and 100 mM 2-(N-morpholino)ethanesulfonic acid (MES), respectively. Especially when 1.5 g L−1 of sodium acetate and 100 mM MES were added simultaneously, the production of hexanoic acid increased up to 2.99 g L−1. Without adding sodium acetate, 2.75 g L−1 of hexanoic acid production from d-galactitol was achieved using a coculture of Clostridium sp. BS-1 and one of the isolates, Clostridium sp. BS-7, in the presence of 100 mM MES. In addition, volatile fatty acid (VFA) production by Clostridium sp. BS-1 from d-galactitol and d-glucose was enhanced when a more reduced culture redox potential (CRP) was applied via addition of Na2S·9H2O. 相似文献
4.
Juan Wang Wen-Yuan Gao Jian Zhang Bei-Mei Zuo Li-Ming Zhang Lu-Qi Huang 《In vitro cellular & developmental biology. Plant》2012,48(1):107-112
Based on the results of carbon source consumption in cell suspension culture of Panax quinquefolium L., 30 g L−1 sucrose was fed into a 5-L stirred tank bioreactor on day 16 of culture to enhance cell density and metabolite production.
Using a fed-batch cultivation strategy, polysaccharide production was enhanced to 1.608 g L−1, which was 1.96-fold greater than with batch cultivation. The maximum saponin yield (7.828 mg L−1) was obtained on day 24 and was about 36% higher than the yields obtained using batch cultivation. In a two-stage culture
process, a combined treatment with sucrose, lactoalbumin hydrolysate, and methyl jasmonate caused a significant increase in
total saponin yield (31.52 mg L−1) in cell cultures after 27 d. This value represents an increase of 4.03-fold compared with the total saponin yield in fed-batch
cultivation. The two-stage culture mode provided the best method for the in vitro production of secondary metabolites from P. quinquefolium. 相似文献
5.
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
6.
Effects of post-harvest application of two plant growth regulators viz., gibberellic acid (GA3) and benzyl adenine (BA) with sucrose in the vase solution on cell membrane stability and vase life of gladiolus were investigated.
The vase solution treatment combinations of GA3 and BA with sucrose significantly increased the membrane stability index and enhanced the vase life as compared to the sucrose
alone treatments or the controls. Vase solution treatment of GA3 (50 mg l−1), followed by BA (50 mg l−1) with sucrose (50 g l−1) significantly increased solution uptake, fresh weight and dry weight of cut spikes. The same treatments also enhanced the
concentration of reducing and non-reducing sugars in gladioli petals 4 days after treatment (DAT). Cut spikes in vase solution
enriched with 50 mg l−1 GA3 + 50 g l−1 sucrose showed higher antioxidative enzyme activities of superoxide dismutase (SOD) and glutathione reductase (GR), lower
lipoxygenase (LOX) activity and lipid peroxidation (measured as TBARS). Petal membrane stability index was also highest in
cut spikes 6 DAT with 50 mg l−1 GA3 + 50 g l−1 sucrose vase solution. Treatment of gladiolus cut spikes with 50 mg l−1 GA3 + 50 g l−1 sucrose vase solution showed two fold increase in vase life and improved flower quality with a higher number of open flower
per spike at any one time. These results suggest that post-harvest application of GA3 (50 mg l−1) with sucrose (50 g l−1) maintains higher spike fresh and dry weight, improves anti-oxidative defence, stabilizes membrane integrity leading to a
delay in petal cell death. 相似文献
7.
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
8.
John Chi-Wei Lan Tau Chuan Ling Grant Hamilton Andrew Lyddiatt 《Biotechnology and Bioprocess Engineering》2006,11(5):425-431
The development of fermentation conditions for the production of C595 diabody fragment (dbFv) inE. coli HB2151 clone has been explored. Investigations were carried out to study the effect of carbon supplements over the expression
period, the comparison of C595 dbfv production in synthetic and complex media, the influence of acetic acid upon antibody
production, and comparison of one-stage and two-stage processes operated at batch or fed-batch modes in bioreactor. Yeast
extract supplied during expression yielded more antibody fragment than any other carbon supply. The synthetic medium presented
higher specific productivity (0.066 mg dbFv g−1 dry cell weight) when compared to the complex medium (0.044 mg dbFv g−1 DCW). The comparison of fermentation strategies demonstrated that (1) one-stage fed-batch fermentation performed higher C595
dbFv production than that operated in batch mode which was significantly affected by acetate concentration; (2) a two-stage
batch operation could enhance C595 dbFv production. It was found that a concentration of 12.3 mg L−1 broth of C595 dbFv and a cell concentration of 10.8 g L−1 broth were achieved at the end of two-stage operation in 5-L fermentation. 相似文献
9.
Hong-Yang Zhu Hong Xu Xiao-Yan Dai Yang Zhang Han-Jie Ying Ping-Kai Ouyang 《Bioprocess and biosystems engineering》2010,33(5):565-571
A new yeast, isolated from natural osmophilic sources, produces d-arabitol as the main metabolic product from glucose. According to 18S rRNA analysis, the NH-9 strain belongs to the genus
Kodamaea. The optimal culture conditions for inducing production of d-arabitol were 37 °C, neutral pH, 220 rpm shaking, and 5% inoculum. The yeast produced 81.2 ± 0.67 g L−1
d-arabitol from 200 g L−1
d-glucose in 72 h with a yield of 0.406 g g−1 glucose and volumetric productivity
Q\textP Q_{\text{P}} of 1.128 g L−1 h−1. Semi-continuous repeated-batch fermentation was performed in shaker-flasks to enhance the process of d-arabitol production by Kodamaea ohmeri NH-9 from d-glucose. Under repeated-batch culture conditions, the highest volumetric productivity was 1.380 g L−1 h−1. 相似文献
10.
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
11.
Michelin M Polizeli Mde L Silva DP Ruzene DS Vicente AA Jorge JA Terenzi HF Teixeira JA 《Journal of industrial microbiology & biotechnology》2011,38(12):1979-1984
Fungi producing high xylanase levels have attracted considerable attention because of their potential industrial applications.
Batch cultivations of Aspergillus terricola fungus were evaluated in stirred tank and airlift bioreactors, by using wheat bran particles suspended in the cultivation
medium as substrate for xylanase and β-xylosidase production. In the stirred tank bioreactor, in physical conditions of 30°C,
300 rpm, and aeration of 1 vvm (1 l min−1), with direct inoculation of fungal spores, 7,475 U l−1 xylanase was obtained after 36 h of operation, remaining constant after 24 h. In the absence of air injection in the stirred
tank reactor, limited xylanase production was observed (final concentration 740 U l−1). When the fermentation process was realized in the airlift bioreactor, xylanase production was higher than that observed
in the stirred tank bioreactor, being 9,265 U l−1 at 0.07 vvm (0.4 l min−1) and 12,845 U l−1 at 0.17 vvm (1 l min−1) aeration rate. 相似文献
12.
Xiao-Hai Feng Fei Chen Hong Xu Bo Wu Jun Yao Han-Jie Ying Ping-Kai Ouyang 《Bioprocess and biosystems engineering》2010,33(9):1077-1085
Propionic acid was produced in a multi-point fibrous-bed (MFB) bioreactor by Propionibacterium freudenreichii CCTCC M207015. The MFB bioreactor, comprising spiral cotton fiber packed in a modified 7.5-l bioreactor, was effective for
cell-immobilized propionic acid production compared with conventional free cell fermentation. Batch fermentations at various
glucose concentrations were investigated in the MFB bioreactor. Based on analysis of the time course of production, a fed-batch
strategy was applied for propionic acid production. The maximum propionic acid concentration was 67.05 g l−1 after 496 h of fermentation, and the proportion of propionic acid to total organic acids was approximately 78.28% (w/w).
The MFB bioreactor exhibited excellent production stability during batch fermentation and the propionic acid productivity
remained high after 78 days of fermentation. 相似文献
13.
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
14.
Yoshifumi Kawana Raiki Yamamoto Yukira Mochida Kunio Suzuki Shigeyuki Baba Hamako Sasamoto 《Plant biotechnology reports》2007,1(4):219-226
Liquid cultures were successfully generated from cotyledons of two Sonneratia species, S. alba and S. caseolaris in Murashige and Skoog (MS) medium containing 0.1 μmol L−1 2,4-dichlorophenoxyacetic acid (2,4-D). Adventitious roots differentiated from cotyledons of S. alba. Proliferated cells were subcultured and a large volume of suspension cells was subsequently established in 100-mL flasks.
All the cytokinins tested inhibited cell proliferation. After three years of culture, the potential to differentiate was tested
as indicated by greening of the cells. Greening occurred when suspension cells were transferred to solid MS medium with and
without 0.1 μmol L−1 2,4-D. Greening was stimulated by low concentrations of the weak auxins indolebutyric acid (IBA) and naphthaleneacetic acid
(NAA) while 2,4-D stimulated late-stage greening. Abscisic acid (ABA) inhibited greening. Gibberellic acid (GA3) at 1.0 μmol L−1 stimulated callus greening and was not inhibitory even when tested at high concentrations. Cytokinins were inhibitory in
combination with 0.1 μmol L−1 of either IBA or NAA. The cause of different effects of plant hormones on growth and differentiation was discussed. Small-scale
liquid media and 24-well culture plates of solid media methods developed in this paper are suitable for the optimization of
hormonal conditions for cell proliferation and differentiation. 相似文献
15.
Succinic acid, a four-carbon diacid, has been the focus of many research projects aimed at developing more economically viable
methods of fermenting sugar-containing natural materials. Succinic acid fermentation processes also consume CO2, thereby potentially contributing to reductions in CO2 emissions. Succinic acid could also become a commodity used as an intermediate in the chemical synthesis and manufacture
of synthetic resins and biodegradable polymers. Much attention has been given recently to the use of microorganisms to produce
succinic acid as an alternative to chemical synthesis. We have attempted to maximize succinic acid production by Actinobacillus succinogenes using an experimental design methodology for optimizing the concentrations of the medium components. The first experiment
consisted of a 24−1 fractional factorial design, and the second entailed a Central Composite Rotational Design so as to achieve optimal conditions.
The optimal concentrations of nutrients predicted by the model were: NaHCO3, 10.0 g l−1; MgSO4, 3.0 g l−1; yeast extract, 2.0 g l−1; KH2PO4. 5.0 g l−1; these were experimentally validated. Under the best conversion conditions, as determined by statistical analysis, the production
of succinic acid was carried out in an instrumented bioreactor using sugarcane bagasse hemicellulose hydrolysate, yielding
a concentration of 22.5 g l−1. 相似文献
16.
Torben Hoefel Eva Wittmann Liv Reinecke Dirk Weuster-Botz 《Applied microbiology and biotechnology》2010,88(2):477-484
Recombinant Cupriavidus necator H 16 with a novel metabolic pathway using a cobalamin-dependent mutase was exploited to produce 2-hydroxyisobutyric acid
(2-HIBA) from renewable resources through microbial fermentation. 2-HIBA production capacities of different strains of C. necator H 16 deficient in the PHB synthase gene and genetically engineered to enable the production of 2-HIBA from the intracellular
PHB precursor (R)-3-hydroxybutyryl-CoA were evaluated in 48 parallel milliliter-scale stirred tank bioreactors (V = 11 mL). The effects of media composition, limitations, pH, and feed rate were studied with respect to the overall process
performances of the different recombinant strains. 2-HIBA production was at a maximum at nitrogen limiting conditions and
if the pH was controlled between 6.8 and 7.2 under fed-batch operating conditions (intermittent fructose addition). The final
concentration of 2-HIBA was 7.4 g L−1 on a milliliter scale. Best reaction conditions identified on the milliliter scale were transferred to a laboratory-scale
fed-batch process in a stirred tank bioreactor (V = 2 L). Two different process modes for the production of 2-HIBA, a single-phase and a dual-phase fermentation procedure,
were evaluated and compared on a liter scale. The final concentration of 2-HIBA was 6.4 g L−1 on a liter scale after 2 days of cultivation. 相似文献
17.
Seven amino acids were tested as precursors to affect pristinamycin production by a mutant strain derived from Streptomyces pristinaespiralis ATCC25486. Of those, glycine was selected as the best precursor to facilitate both cell growth and pristinamycin production
at the feeding time of 36-h incubation and the feeding rate of 0.75 g L−1 flask culture. The optimized time and concentration of glycine feeding were applied to enlarged 3-L bioreactor fermentation
with a resin added at the time of 20-h fermentation for in situ separation. As a result, a combination of the glycine feeding
and the added resin resulted in the maximal pristinamycin yield of 616 mg L−1 culture 12 h after glycine feeding. The yield from the combined treatment was 1.71-, 2.77- and 4.32-fold of those from the
mere glycine and resin treatments and the control, respectively. Other parameters, including intracellular nucleic acid content,
animo nitrogen content and pH level, during 72-h fermentation were also given in association with the pristinamycin yields
in the different treatments. The results indicate that glycine feeding is an effective approach to enhance pristinamycin production
in the culture of S. pristinaespiralis F213 with supplemented resin for in situ separation. 相似文献
18.
Gibberellic acid (GA3) is a commercially important plant growth hormone, which is gaining much more attention all over the world due to its effective
use in agriculture and brewing industry. Industrially it is produced by submerged fermentation technique using Ascomycetous
fungusGibberella fujikuroi. Solid state and immobilized cell fermentation techniques had also been developed as an alternative to obtain higher yield
of GA3. This review summarizes the problems of GA3 fermentation such as production of co-secondary metabolites along with GA3, substrate inhibition and degradation of GA3 to biologically inert compound gibberellenic acid, which limits the yield of GA3 in the fermentation medium. These problems can be overcome by various bioprocessing strategiese.g. two-stage and fed batch cultivation processes. Further research on bioreactor operation strategies such as continuous and/or
extractive fermentation with or without cell recycle/retention system need to be investigated for improvement in yield and
productivity. Down stream processing for GA3 isolation is also a challenge and procedures available for the same have been critically evaluated. 相似文献
19.
The cashew fruit (Anacardium occidentale L.) has been used as a promising agricultural resource for the production of low-molecular weight (MW) hyaluronic acid (HA) (104–105 Da). The cashew juice is a rich source of vitamin C containing, 1.2–2.0 g L−1. This work explores the effects of the initial concentration of the ascorbate on the solid fermentation of the juice-moisturized
bagasse from the cashew apple fruit. The results show that the MW reduction of HA is proportional to the initial ascorbate concentration. The presence of ascorbate did not influence the Streptococcus zooepidemicus metabolism. However, the HA productivity was increased from 0.18 to 0.28 mg g−1 h−1 when the ascorbate concentration ranged from 1.7 to 10 mg mL−1. These findings contribute to the controlled production of HA in a low MW range, which is important in cell signalization, angiogenesis and nanoparticles production. 相似文献
20.
Jesús Adolfo Jiménez Nieves Alonso-Blázquez Dolores López-Vela Cristina Celestino Mariano Toribio Jesus Alegre 《In vitro cellular & developmental biology. Plant》2011,47(5):578-588
Somatic embryogenesis can be induced in the leaves of cork oak (Quercus suber L.) trees. The use of this propagation system in multivarietal forestry requires the mass production of cloned plants at
low cost. Investigations were made into the influence of three types of Erlenmeyer flask and three orbiting speeds (60, 110,
and 160 rpm) on oxygen transfer rate (KL
a), the shear force index (SFI), biomass production, and the proliferation of embryogenic clumps (EMCs) in cultures during
the proliferation phase. KL
a varied between 0.11 and 1.47 h−1 without biomass production being limited by oxygen availability. The EMCs grew even in hypoxic conditions, although the suppression
of gaseous exchange strongly reduced biomass production. Cultures with different levels of hydrodynamic stress and SFI values
(1.4·10−3–8.8·10−3 cm min−1) were obtained. Proliferation rates of EMCs increased with agitation rate and the SFI. The largest number of EMCs was obtained
in baffled flasks agitated at 160 rpm (KL
a of 1.47 h−1, and SFI of 8.8·10−3 cm min−1) with mild hydrodynamic stress enhancing growth. Biomass production increased with agitation and hydrodynamic stress, but
only when the SFI value was below 5·10−3 cm min−1. The greatest biomass production was obtained in smooth 100 ml flasks agitated at 160 rpm. The differentiation of embryos
was favoured by the lowest KL
a (0.11 h−1) and SFI (1.40·103 cm min−1) values, achieved using these flasks when agitated at 60 rpm. 相似文献