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1.
Beng Ti Tey Mung Ing Chua Ghee Sung Chua Michelle Yeen Tan Ng Dayang Radiah Awang Biak Wen Siang Tan Tau Chuan Ling 《Biotechnology and Bioprocess Engineering》2006,11(2):164-167
The influence of temperature and agitation on the growth ofEscherichia coli expressing hepatitis B core antigen (HBcAg) in stirred tank bioreactor were investigated. The highest specific growth rate
forE. coli (0.844 h−1) was achieved at a temperature of 37°C and an agitation speed of 250 rpm. The activation energy for the growth of theE. coli strain W3110IQ in the stirred tank bioreactor was estimated to be 11 kcal/mol. The highest protein yield was achieved at
a temperature of 44°C and an agitation speed of 250 rpm. The relative protein concentration at 44°C is 30 and 6% higher compared
to that at 30 and 37°C, respectively. 相似文献
2.
Woo Jun Kim Woo Gi Lee Kalaimahan Theodore Ho Nam Chang 《Biotechnology and Bioprocess Engineering》2001,6(1):6-10
The production of chitosan from the mycelia ofAbsidia coerulea was studied to improve cell growth and chitosan productivity. Culture conditions were optimized in batch cultivation (pH
4.5 agitator speed of 250 rpm, and aeration rate of, 2 vvm) and the maximum chitosan concentration achieved was 2.3 g/L under
optimized conditions. Continuous culture was carried out successfully by the formation of new growth spots under optimized
conditions, with a chitosan productivity of 0.052 gL−1 h−1, which is the highest value to date, and was obtained at a dilution rate of 0.05 h−1. Cell chitosan concentrations reached about 14% in the steady state, which is similar to that achieved in batch culture.
This study shows that for the continuous culture ofAbsidia coerulea it is vital to control the medium composition. 相似文献
3.
The effect of pH, aeration and mixing on the growth and production of carbonyl reductase by Candida viswanathii was investigated in a 6.6-l fermentor. Controlling the pH at 8.0 had a very significant effect on the enzyme production.
Aeration and agitation influenced the dissolved oxygen concentration which in turn affected growth as well as enzyme production.
A maximum carbonyl reductase activity (53 Umg−1) was attained in 24 h under the optimal cultivation conditions of controlled pH at 8.0, aeration rate 1 vvm and an agitation
speed of 250 rpm at 25°C. The enzyme activity was twice as high (56 Umg−1) in the fermentor as compared to a shake flask. Further, the duration of growth and enzyme production in the fermentor was
shortened. Cells cultivated under the optimized conditions were used for the preparative scale reduction of N, N-dimethyl-(3-keto)-2-thienyl-propanamine
to (S)-N, N-dimethyl-(3-hydroxy)-2-thienyl-propanamine, a key intermediate in the production of the important antidepressant drug
(S)-duloxetine. 相似文献
4.
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
5.
The Kluyveromyces marxianus strains CBS 6556, CBS 397 and CBS 712T were cultivated on a defined medium with either glucose, lactose or sucrose as the sole carbon source, at 30 and 37°C. The
aim of this work was to evaluate the diversity within this species, in terms of the macroscopic physiology. The main properties
evaluated were: intensity of the Crabtree effect, specific growth rate, biomass yield on substrate, metabolite excretion and
protein secretion capacity, inferred by measuring extracellular inulinase activity. The strain Kluyveromyces lactis CBS 2359 was evaluated in parallel, since it is the best described Kluyveromyces yeast and thus can be used as a control for the experimental setup. K. marxianus CBS 6556 presented the highest specific growth rate (0.70 h−1) and the highest specific inulinase activity (1.65 U mg−1 dry cell weight) among all strains investigated, when grown at 37°C with sucrose as the sole carbon source. The lowest metabolite
formation and highest biomass yield on substrate (0.59 g dry cell weight g sucrose−1) was achieved by K. marxianus CBS 712T at 37°C. Taken together, the results show a systematic comparison of carbon and energy metabolism among three of the best
known K. marxianus strains, in parallel to K. lactis CBS 2359. 相似文献
6.
Nitrogenous excretion in two snails, Littorina saxatilis (high intertidal) and L. obtusata (low intertidal) was studied in relation to temperature acclimation (at 4° and 21°C), including total N excretion rates,
the fraction of urea in N excretion, corresponding O:N ratios and the partitioning of deaminated protein between catabolic
and anabolic processes at 4°, 11° and 21°C. Aggregate N excretion rates in both species showed no significant compensatory
adjustments following acclimation. Total weight specific N excretion rates at 21°C were higher in standard 3 mg L. saxatilis (739 ng N mg−1 h−1) than standard 5 mg L. obtusata (257 ng N mg−1 h−1) for snails acclimated to 21°C. Comparisons of Q10 values of total weight specific N excretion to Q10 values for weight specific oxygen consumption ({xxV}O2) between 4° to 11 °C and 11° to 21°C indicated that, while total rates of catabolic metabolism ({xxV}O2) and protein deamination in L. obtusata were essentially parallel, the relationship between N excretion and {xxV}O2 in L. saxatilis revealed the partitioning of a larger share of deaminated protein carbon into anabolism at 4° and 21°C than at 11°C. Urea
N accounted for a larger share of aggregate N excreted in L. saxatilis than in L. obtusata, but in both species urea N is a greater proportion of total N excreted when acclimated at 4°C (urea N: ammonia N ratio range:
1 to 2.15) than in snails acclimated to 21°C (urea N: ammonia N ratio range: 0.46 to 1.39). Molar O:N ratios indicate that
the proportion of metabolism supported by protein catabolism is greater in L. saxatilis (O:N range: 2.5–8.4) than in L. obtusata (O:N range: 7.3–13.0). In both species, regardless of acclimation temperature, the O:N ratios are generally lowest (high
protein catabolism) at 4°C and highest at 21°C. 相似文献
7.
Adedayo O. Javadpour S. Taylor C. Anderson W.A. Moo-Young M. 《World journal of microbiology & biotechnology》2004,20(6):545-550
Bacterial cultures from a wastewater treatment plant degraded a toxic azo dye (methyl red) by decolourization. Complete decolourization
using a mixed-culture was achieved at pH 6, 30 °C within 6 h at 5 mg/l methyl red concentration, and 16 h at 20—30 mg/l. Four
bacterial species were isolated that were capable of growth on methyl red as the sole carbon source, and two were identified,
namely Vibrio logei and Pseudomonas nitroreducens. The Vibrio species showed the highest methyl red degradation activity at the optimum conditions of pH 6--7, and 30—35 °C. Analysis by
NMR showed that previously reported degradation products 2-aminobenzoic acid and N,N-dimethyl-1,4-phenylenediamine were not
observed. The decolourized dye was not toxic to a monkey kidney cell line (COS-7) at a concentration of 250 μM.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Optimal conditions for chitinase production by<Emphasis Type="Italic">Serratia marcescens</Emphasis>
A chitinase-producing bacterium was isolated from seashore mud around Beobseongpo in Chunmam province through the use of a
selective enrichment culture. The best chitinase producing strain was isolated and identified asSerratia marcescens KY from its characteristics. For effective production of chitinase, optimum pH, temperature, and agitation speed were investigated
in flask cultures. The optimum pH usingSerratia marcescens KY was between pH 6 and 7 and the chitinase produced was 37.9 unit/mL. On the other hand, the optimal pH of theSerratia marcescens ATCC 27117 was 7.5, and the produced amount of chitinase was 35.2 unit/mL. The optimal temperature for chitinase production
forSerratia marcescens KY andSerratia marcescens ATCC 27117 was 30°C. The cell growth pattern at different temperature was almost identical to the chitinase production. To
investigate the optimal shaking speed under optimal culture, speeds were varied in the range of 0≈300 rpm. The maximum production
of chitinase was carried at 200 rpm although the cell growth was the highest at 150 rpm. It indicates that oxygen adjustment
is required for the maximum chitinase production. Using optimal conditions, batch cultures for comparingSerratia marcescens KY andSerratia marcescens ATCC 27117 were carried out in a 5 L fermentor. The oxygen consumption was increased with the increase of culture. Especially,
at 120 h of cultureSerratia marcescens KY andSerratia marcescens ATCC 27117 produced 38.3 unit/mL, and 33.5 unit/mL, respectively. 相似文献
9.
Alvaro Israel Milagrosa Martinez-Goss Michael Friedlander 《Journal of applied phycology》1999,11(6):543-549
Acclimation responses of the red alga Gracilaria tenuistipitata var. liui collected on the northwest coast of Philippines were determined in laboratory setups and outdoor cultivation tanks in Haifa,
Israel. Growth under laboratory conditions was influenced by all three variables studied, namely, temperature (20 or 30 °C), salinity (20, 30 or39‰) and seawater pH (6.5, 7.0, 8.0 or ≥ 9.0). In 250 mL flasks lacking pH control growth was influenced
by temperature only at 20 ‰, whereas at 39 ‰, growth rates were similar at 20 or 30 °C. In 500 mL cylinders in which pH was controlled, growth rates were significantly different at a pH of 6.5 and 7.0 for all
salinities, with maximal rates occurring in 39 ‰. At pH 8.0, and above, growth rates between salinities were similar and reduced
to approximately 50% at a pH of 9.0 compared to rates at a pH of 6.5. Photosynthesis responses generally resembled growth
responses both, in 250 mL and 500 mL cultures. In 40-L outdoor tanks, weekly growth and agar yields were apparently enhanced
by increasing light intensities (up to full sunlight) and nutrient concentrations (up to 0.2 mM PO3
2- and 2.0 mM NH4
+), and rates averaged four times higher than rates determined in the smaller flask cultures. This study shows broad salinity
tolerance of G. tenuistipitata var. liui and its ability to sustain growth rates that are among the highest measured for Gracilaria spp. in outdoor cultures.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
10.
H. E. M. Mc Mahon C. T. Kelly W. M. Fogarty 《Applied microbiology and biotechnology》1997,48(4):504-509
The α-amylase of Streptomyces sp. IMD 2679 was subject to catabolite repression. Four different growth rates were achieved when the organism was grown
at 40 °C and 55 °C in the presence and absence of cobalt, with an inverse relationship between α-amylase production and growth
rate. Highest α-amylase yields (520 units/ml) were obtained at the lowest growth rate (0.062 h−1), at 40 °C in the absence of cobalt, while at the highest growth rate (0.35 h−1), at 55 °C in the presence of cobalt, α-amylase production was decreased to 150 units/ml. As growth rate increased, the rate
of specific utilisation of the carbon source maltose also increased, from 46 to 123 μg maltose (mg biomass)−1 h−1. The pattern and levels of α-glucosidase (the enzyme degrading maltose) detected intracellularly in each case, indicate that
growth rate effectively controls the rate of feeding of glucose to the cell, and thus catabolite repression.
Received: 17 February 1997 / Received revision: 29 April 1997 / Accepted: 11 May 1997 相似文献
11.
Anjali Madhavan Sriappareddy Tamalampudi Aradhana Srivastava Hideki Fukuda Virendra S. Bisaria Akihiko Kondo 《Applied microbiology and biotechnology》2009,82(6):1037-1047
Previously, a Saccharomyces cerevisiae strain was engineered for xylose assimilation by the constitutive overexpression of the Orpinomyces xylose isomerase, the S. cerevisiae xylulokinase, and the Pichia stipitis SUT1 sugar transporter genes. The recombinant strain exhibited growth on xylose, under aerobic conditions, with a specific growth
rate of 0.025 h−1, while ethanol production from xylose was achieved anaerobically. In the present study, the developed recombinant yeast was
adapted for enhanced growth on xylose by serial transfer in xylose-containing minimal medium under aerobic conditions. After
repeated batch cultivations, a strain was isolated which grew with a specific growth rate of 0.133 h−1. The adapted strain could ferment 20 g l−1 of xylose to ethanol with a yield of 0.37 g g−1 and production rate of 0.026 g l−1 h−1. Raising the fermentation temperature from 30°C to 35°C resulted in a substantial increase in the ethanol yield (0.43 g g−1) and production rate (0.07 g l−1 h−1) as well as a significant reduction in the xylitol yield. By the addition of a sugar complexing agent, such as sodium tetraborate,
significant improvement in ethanol production and reduction in xylitol accumulation was achieved. Furthermore, ethanol production
from xylose and a mixture of glucose and xylose was also demonstrated in complex medium containing yeast extract, peptone,
and borate with a considerably high yield of 0.48 g g−1. 相似文献
12.
Kang-Ik Jo You-Jung Lee Bo-Kyung Kim Bo-Hwa Lee Chung-Han Chung Soo-Wan Nam Sung-Koo Kim Jin-Woo Lee 《Biotechnology and Bioprocess Engineering》2008,13(2):182-188
Optimal conditions for pilot-scale production of the carboxymethylcellulase (CMCase) by Bacillus amyloliquefaciens DL-3 were investigated. The best carbon and nitrogen sources for the production of CMCase by B. amyloliquefaciens DL-3 were found to be rice hull and peptone and their optimal concentrations were 5.0 and 0.20% (w/v), respectively. Optimal
temperature and initial pH for the production of CMCase were 37°C and 6.8. Optimal agitation speed and aeration rate for the
production of CMCase were 300 rpm and 1.0 vvm in a 7 L bioreactor, which were different from those for the cell growth of
B. amyloliquefaciens DL-3. The highest productions of CMCase by B. amyloliquefaciens DL-3 from 5.0% (w/v) rice hull as a carbon source under optimal conditions in a 7 or 100 L bioreactor were 220 and 367 U/mL,
respectively. 相似文献
13.
Kyung-Taek Oh Young-Ju Kim Nam Van Nguyen Woo-Jin Jung Ro-Dong Park 《Biotechnology and Bioprocess Engineering》2008,13(5):566-570
Demineralization (DM) from crab shell (CS) waste was carried out using a lactic acid-producing bacterium, Lactobacillus paracasei subsp. tolerans KCTC-3074 for 7 days at 25, 30, and 35°C. DM rates were 89∼92% and slightly affected by temperature. DM was also performed
for four particle-sized shell samples (0.84∼3.35, 3.35∼10, 10∼20, and 20∼35 mm) with 10% inoculum, 5% shell, and 10% glucose
at 30°C and 180 rpm for 7 days. It was found out that the shell size had a slight effect on the rate of DM. Negative relationships
were found between DM and residual dry weight (r2 = 0.960), and between DM and pH (r2 = 0.906). Conversely, positive relationships were found between DM and medium protein (r2 = 0.696), and between DM and total titratable acidity (r2 = 0.630). 相似文献
14.
In order to test whether piperazinium dilactate can be produced by fermentation in its exact stoichiometric composition without losses of yield, the kinetics of cell growth and lactate production were investigated in the batch cultivation of Lactobacillus paracasei, using piperazine as a neutralizer in pH control. It was found that piperazine dilactate is formed in its stoichiometric composition at about pH 5.0, and lactic acid fermentation occurred with yields of about 90% under these conditions. Piperazine at concentrations less than or equal to 50 g/l did not affect growth and product formation. The presence or absence of piperazine did not produce any significant differences in either the maximum specific growth rate or the maximum specific lactate formation rate when piperazine was present or absent (0.65 h—1 compared to 0.68 h—1 and 3.86 g/g × h compared to 3.63 g/g × h, respectively). The Luedeking‐Piuret relationship between the two quantities was also not changed significantly when piperazine was added. To estimate the optimum parameters for cell growth and lactate formation in the presence of piperazine, a factorial experiment was designed and carried out under consideration of the parameter ranges 5.0 ≤ pH ≤ 7.0 and 30 °C ≤ T ≤ 36 °C. In this way, three‐dimensional models of the specific growth rate, the specific lactate formation rate and the lactate yield were obtained. 相似文献
15.
L. Moeller B. Strehlitz A. Aurich A. Zehnsdorf T. Bley 《Engineering in Life Science》2007,7(5):504-511
Citric acid (CA) is mainly produced in a biotechnological process using Aspergillus niger. In this process, large amounts of wastes have to be removed. Since the use of Yarrowia lipolytica for CA production is an environmental compatible alternative method, the CA production was optimized in regard to growth temperature and pH as well as substrate and product inhibition. The highest value of the maximum specific growth rate at pH 6.5 was found to be μmax = 0.192 h–1, whereas the largest amount of CA of 24.91 g/L as well as the highest selectivity of the bioprocess (89.9 % CA) and the maximum yield (0.22 gCA/gGlucose) were obtained at pH 6.0. During the growth phase, the temperature optimum was found to be in the range of 30–34 °C (μmax = 0.132 h–1). Nevertheless, the highest concentration of CA during the production phase was obtained at 30 °C (41 g/L CA, 93.1 % CA, 0.55 gCA/gglucose). In studying the substrate inhibition of the process, a clear tendency of decrease in the maximum specific growth rate was detected when the initial glucose concentration was increased from 50 g/L (μmax = 0.17 h–1) to 200 g/L (μmax = 0.055 h–1). The addition of 120 g/L CA to the culture broth at the start of the production phase reduced the production of CA from 32.1 g/L to 7.4 g/L. 相似文献
16.
Fed-batch cultures of recombinant Escherichia coli BL21 for producing human-like collagen were performed at different specific growth rates (0.1~0.25 h−1) before induction and at a constant value of 0.05 h−1 after induction by the method of pseudo-exponential feeding. Although the final biomass (around 69 g l−1) was almost the same in all fed-batch cultures, the highest product concentration (13.6 g l−1) was achieved at the specific growth rate of 0.15 h−1 and the lowest (9.6 g l−1) at 0.25 h−1. The mean productivity of human-like collagen was the highest at 0.15 h−1 (0.57 g l−1 h−1) and the lowest at 0.1 h−1 (0.35 g l−1 h−1). In the phase before induction, the cell yield coefficient (YX/S) decreased when the specific growth rate increased, while the formation of acetic acid increased upto 2.5 g l−1 at 0.25 h−1. The mean product yield coefficient (YP/S) also decreased with specific growth rate increasing. The respiration quotient (RQ) increased slightly with specific growth rate increasing before induction, and the mean value of RQ was around 72%. The optimum growth rate for human-like collagen production was 0.15~0.2 h−1. 相似文献
17.
Production of the bacteriocin pediocin SM‐1 by Pediococcus pentosaceus Mees 1934 was investigated in pH‐controlled batch and chemostat cultures using a complex medium containing glucose, sucrose or fructose. In chemostat cultures operated at 150 rpm, 30°C, 60% dissolved oxygen tension, pH 6.5, and D = 0.148 h?1, the pediocin titer reached 185 AU/mL representing an increase of 32% compared with batch cultures in which glucose was used as the carbon source. Pediocin biosynthesis was markedly affected by the growth rate of the producer microorganism. For all carbon sources tested, pediocin production appeared to take place only at dilution rates lower than μmax. However, only glucose supported production at the very low dilution rate of 0.05 h?1 indicating a direct regulation of pediocin biosynthesis by the carbon source. Glucose supported higher biomass productivity and higher pediocin titers and yields compared with the other sugars used. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1481–1486, 2015 相似文献
18.
Large‐scale culture of a megakaryocytic progenitor cell line with a single‐use bioreactor system 下载免费PDF全文
Retno Wahyu Nurhayati Yoshihiro Ojima Takeaki Dohda Masahiro Kino‐Oka 《Biotechnology progress》2018,34(2):362-369
The increasing application of regenerative medicine has generated a growing demand for stem cells and their derivatives. Single‐use bioreactors offer an attractive platform for stem cell expansion owing to their scalability for large‐scale production and feasibility of meeting clinical‐grade standards. The current work evaluated the capacity of a single‐use bioreactor system (1 L working volume) for expanding Meg01 cells, a megakaryocytic (MK) progenitor cell line. Oxygen supply was provided by surface aeration to minimize foaming and orbital shaking was used to promote oxygen transfer. Oxygen transfer rates (kLa) of shaking speeds 50, 100, and 125 rpm were estimated to be 0.39, 1.12, and 10.45 h?1, respectively. Shaking speed was a critical factor for optimizing cell growth. At 50 rpm, Meg01 cells exhibited restricted growth due to insufficient mixing. A negative effect occurred when the shaking speed was increased to 125 rpm, likely caused by high hydrodynamic shear stress. The bioreactor culture achieved the highest growth profile when shaken at 100 rpm, achieving a total expansion rate up to 5.7‐fold with a total cell number of 1.2 ± 0.2 × 109 cells L?1. In addition, cells expanded using the bioreactor system could maintain their potency to differentiate following the MK lineage, as analyzed from specific surface protein and morphological similarity with the cells grown in the conventional culturing system. Our study reports the impact of operational variables such as shaking speed for growth profile and MK differentiation potential of a progenitor cell line in a single‐use bioreactor. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:362–369, 2018 相似文献
19.
Extracellular human granulocyte-macrophage colony stimulating factor (hGM-CSF) expression was studied under the control of
the GAP promoter in recombinant Pichia pastoris in a series of continuous culture runs (dilution rates from 0.025 to 0.2 h−1). The inlet feed concentration was also varied and the steady state biomass concentration increased proportionally demonstrating
efficient substrate utilization and constancy of the biomass yield coefficient (Yx/s) for a given dilution rate. The specific product formation rate (qP) showed a strong correlation with dilution rates demonstrating growth associated product formation of hGM-CSF. The volumetric
product concentration achieved at the highest feed concentration (4×) and a dilution rate of 0.2 h−1 was 82 mg l−1 which was 5-fold higher compared to the continuous culture run with 1× feed concentration at the lowest dilution rate thus
translating to a 40 fold increase in the volumetric productivity. The specific product yield (YP/X) increased slightly from 2 to 2.5 mg g−1, with increasing dilution rates, while it remained fairly invariant, for all feed concentrations demonstrating negligible
product degradation or feed back inhibition. The robust nature of this expression system would make it easily amenable to
scale up for industrial production. 相似文献
20.
Jin Young Lee Seong Woo Kang Seung Wook Kim 《Biotechnology and Bioprocess Engineering》2008,13(1):1-6
Verticillium lecanii is recognized as an entomopathogenic fungus, and has high potential in the biological control of pests. In this study, it
was investigated that the relationship between agitation speed in a 2.5 L stirred tank reactor (STR) at 25°C and initial pH
5.5, and the morphological characteristics of V. lecanii CS-625, such as hyphal length/width, spore length/width, and the number of tips during spore production. The agitation speed
affected the hyphae patterns and the number of tips. The number of spores rapidly increased at 48 to 60 h of cultivation,
and the highest spore productivity (2.5 × 1010 spore/L·h at 60 h) occurred with an agitation speed of 350 rpm and an aeration rate of 1.0 vvm. The number of tips increased
in proportion to the increase in spore production during the same culture time. The highest number of tips (4.8 × 108 tipJ.mL) was obtained at 72 h of cultivation. The shortest mean spore length (2.8 μm) was obtained at 60 h of cultivation. Therefore,
it was determined that the increased number of tips and decreased mean spore length were closely related to the production
of V. lecanii spores. 相似文献