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1.
Valiollah Babaeipour Seyed Abbas Shojaosadati Rasoul Khalilzadeh Nader Maghsoudi Amir Mohammad Farnoud 《Applied biochemistry and biotechnology》2010,160(8):2366-2376
Development of inexpensive and simple culture media and appropriate induction conditions are always favorable for industry.
In this research, chemical composition and stoichiometric data for γ-interferon production and recombinant Escherichia coli growth were used in order to achieve a simple medium and favorable induction conditions. To achieve this goal, the effects
of medium composition and induction conditions on the production of γ-interferon were investigated in batch culture of E. coli BL21 (DE3) [pET3a-ifnγ]. These conditions were considered as suitable conditions for the production of γ-interferon: 2.5× M9 medium, supplemented
with a mixture of amino acids (milligram per liter), including glutamic acid 215, aspartic acid 250, lysine 160, and phenylalanine
90, and induction at late-log phase (OD600 = 4.5). Under these conditions, dry cell weight of 6 ± 0.2 g/l and γ-interferon concentration of 2.15 ± 0.1 g/l were obtained.
Later, without changing the concentration ratio of amino acids and glucose, the effect of increase in the primary glucose
concentration on productivity of γ-interferon was investigated. It was found that 25 g/l glucose will result in maximum attainable
biomass and recombinant human γ-interferon. At improved conditions, a dry cell weight of 14 ± 0.2 g/l, concentration and overall
productivity of γ-interferon 4.2 ± 0.1 g/l and 420 ± 10 mg/l h, respectively, were obtained. 相似文献
2.
The alterations of organic acids citrate, α-ketoglutarate, succinate, fumarate, malate production together with isocitrate
lyase activity as a glyoxalate shunt enzyme, and antibiotic production of Streptomyces sp M4018 were investigated in relation to changes in the glucose, glycerol and starch concentrations (5–20 g/L) after identification
as a strain of Streptomyces hiroshimensis based on phenotypic and genotypic characteristics. The highest intracellular citrate and α-ketoglutarate levels in 20 g/l
of glucose, glycerol, and starch mediums were 399.47 ± 4.78, 426.93 ± 6.40, 355.84 ± 5.38 ppm and 444.81 ± 5.12, 192.96 ± 2.26,
115.20 ± 2.87 ppm, respectively. The highest succinate, malate, and fumarate levels were also determined in 20 g/l of glucose
medium as 548.9 ± 11.21, 596.15 ± 8.26, and 406.42 ± 6.59 ppm and the levels were significantly higher than the levels in
glycerol and starch. Extracellular organic acid levels measured also showed significant correlation with carbon source concentrations
by showing negative correlation with pH levels of the growth medium. The antibiotic production of Streptomyces sp. M4018 was also higher in glucose medium as was the case also for organic acids when compared with glycerol. On the other
hand, there is no production in starch. 相似文献
3.
Min Jiang Kequan Chen Zhongmin Liu Ping Wei Hanjie Ying Honam Chang 《Applied biochemistry and biotechnology》2010,160(1):244-254
To develop a cost-effective fermentation medium, spent brewer's yeast hydrolysate was evaluated as a nitrogen source for succinic
acid production by Actinobacillus succinogenes NJ113 in glucose-containing media. Autolysis and enzymatic hydrolysis were used to hydrolyze the spent brewer's yeast cells
to release the nutrients. The results showed that enzymatic hydrolysis was a more effective method due to the higher succinic
acid yield and cell growth. However, the incomplete glucose consumption indicated existence of nutrient limitation. Vitamins
were subsequently identified as the main limiting factors for succinic acid production using enzymatically hydrolyzed spent
brewer's yeast as a nitrogen source. After the addition of vitamins, cell growth and succinic acid concentration both improved.
As a result, 15 g/L yeast extract could be successfully replaced with the enzymatic hydrolysate of spent brewer's yeast with
vitamins supplementation, resulting in a production of 46.8 g/L succinic acid from 68 g/L glucose. 相似文献
4.
A novel laccase producing Basidiomycete Peniophora sp. (NFCCI-2131) was isolated from pulp and paper mill effluent. The optimal temperature and initial pH for laccase production
by the isolate in submerged culture were found to be 30 and 4.6° C, respectively. Maltose (20 g l−1) and tryptone (1.0 g l−1) were the most suitable carbon and nitrogen sources for laccase production. Cu2+ (1.0 mM) and veratryl alcohol induced maximum laccase production giving 6.6 and 6.07 U/ml laccase activity, respectively.
Under optimised culture conditions, 7.6 U/ml activity was obtained, which was 2.4 times higher than that was achieved in basal
medium. An evaluation of the delignification efficiency of the crude enzyme in the presence of redox mediators [2,2’-azino-bis(3-ethylbenzthiazoline-6-sulphonic
acid) and (1-hydroxybenzotriazole)] revealed structural changes in lignin and existence of many active centres for both chemical
and biological degradation of lignin following enzymatic treatment. 相似文献
5.
Xu JL Zhao J Wang LF Sun HY Song CL Chi ZM 《Applied biochemistry and biotechnology》2012,166(3):599-611
In order to isolate β-galactosidase overproducers of the psychrotolerant yeast Guehomyces pullulans 17–1, its cells were mutated by using nitrosoguanidine (NTG). One mutant (NTG-133) with enhanced β-galactosidase production was
obtained. The mutant grown in the production medium with 30.0 g/l lactose and 2.0 g/l glucose could produce more β-galactosidase
than the same mutant grown in the production medium with only 30.0 g/l lactose while β-galactosidase production by its wild
type was sensitive to the presence of glucose in the medium. It was found that 40.0 g/l of the whey powder was the most suitable
for β-galactosidase production by the mutant. After optimization of the medium and cultivation conditions, the mutant could
produce 29.2 U/ml of total β-galactosidase activity within 132 h at the flask level while the mutant could produce 48.1 U/ml
of total β-galactosidase activity within 144 h in 2-l fermentor. Over 77.1% of lactose in the whey powder (5.0% w/v) was hydrolyzed
in the presence of the β-galactosidase activity of 280 U/g of lactose within 9 h while over 77.0% of lactose in the whey was
hydrolyzed in the presence of β-galactosidase activity of 280 U/g of lactose within 6 h. This was the first time to show that
the β-galactosidase produced by the psychrotolerant yeast could be used for hydrolysis of lactose in the whey powder and whey. 相似文献
6.
Response surface methodology (RSM) was employed for optimization of medium components and cultural parameters in cost effective
cane molasses based medium for attaining high yield of succinic acid. The important factors obtained by “one-variable-at-a-time-approach”
(cane molasses, corn steep liquor, sodium carbonate, and inoculum density) were further optimized by RSM. The optimum values
of the parameters obtained through RSM (cane molasses 12.5%, corn steep liquor 7.5%, and sodium carbonate 25 mM) led to almost
double yield of succinic acid (15.2 g/l in 36 h) as against “one-variable-at-a-time-approach” (7.1 g/l in 36 h) in 500-ml
anaerobic bottles containing 300-ml cane molasses based medium. Subsequently, in 10-l bioreactor succinic acid production
from Escherichia coli was further improved to 26.2 g/l in 30 h under conditions optimized through RSM. This fermentation-derived succinic acid
will definitely help in replacing existing environmentally hazardous and cost-intensive chemical methods for the production
of succinic acid. 相似文献
7.
The optimization of process parameters for high amylase production by Saccharomycopsis fibuligera A11 in solid-state fermentation was carried out using central composite design. Finally, the optimal parameters obtained
with the response surface methodology (RSM) were moisture 610.0 ml/kg, inoculum 30.0 ml (OD600 nm = 20.0)/kg, the amount ratio of wheat bran to rice husk 0.42, cassava starch concentration 20.0 g/kg, temperature 28 °C,
and natural pH. Under the optimized conditions, 4,296 U/g of dry substrate of amylase activity was reached in the solid-state
fermentation culture of the yeast strain A11 within 160 h, whereas the predicted maximum amylase activity of 4,222 U/g of
dry substrate of amylase activity was derived from the RSM regression. It was found that cassava starch can be actively converted
into monosaccharides and oligosaccharides by the crude amylase. 相似文献
8.
Gang Li Suling Yang Lingbo Qu Ran Yang Jianjun Li 《Journal of Solid State Electrochemistry》2011,15(1):161-166
A Nafion/multi-wall carbon nanotubes (MWNT) composite film-modified electrode was fabricated. The modified electrode showed
excellent electrocatalytic activity toward ascorbic acid (AA) and uric acid (UA) in 0.1-mol L−1 NaCl medium (pH 6.5). Compared to the bare electrode that only displayed a broad and overlapped oxidation peak, the Nafion/MWNT
film-modified electrode not only remarkably enhanced the anodic peak currents of AA and UA but also avoided the overlapping
of the anodic peaks of AA and UA with a 320-mV separation of both peaks. Under the optimized conditions, the peak currents
of AA and UA were proportional to their concentration at the ranges of 8.0 × 10−5 to 6.0 × 10−3 mol L−1 and 6.0 × 10−7 to 8.0 × 10−5 mol L−1, respectively. The proposed method was used for the detection of AA and UA in real samples with satisfactory results. 相似文献
9.
The production of propionic acid by Propionibacterium freudenreichii CCTCC M207015 was investigated in a 7.5-l stirred-tank fermentor. Batch fermentations by P. freudenreichii CCTCC M207015 at various pH values ranging from 5.5 to 7.0 were studied. Based on the analysis of the time course of specific
cell growth rate (μ
x) and specific propionic acid formation rate (μ
p), a two-stage pH-shift control strategy was proposed. At first 48 h, pH was controlled at 6.5 to obtain the maximal μ
x, subsequently pH 6.0 was used to maintain high μ
p to enhance the production of propionic acid. By applying this pH-shift control strategy in propionic acid fermentation, the
maximal propionic acid and glucose conversion efficiency had a significant improvement and reached 19.21 g/l and 48.03%, respectively,
compared with those of constant pH operation (14.58 g/l and 36.45%). Fed-batch fermentation with pH-shift control strategy
was also applied to produce propionic acid; the maximal propionic acid yield and glucose conversion efficiency reached 25.23 g/l
and 47.76%, respectively. 相似文献
10.
11.
Glycerol would stimulate the production of poly(γ-glutamic acid) (γ-PGA) and decrease its molecular weight in Bacillus subtilis NX-2. When 20 g/l glycerol was added in the medium, the yield of γ-PGA increased from 26.7 ± 1.0 to 31.7 ± 1.3 g/l, and molecular
weight of γ-PGA decreased from 2.43 ± 0.07 × 106 to 1.86 ± 0.06 × 106 Da. In addition, it was found that the decrease of γ-PGA chain length by glycerol would lead to the decrease of broth viscosity
during the fermentation and enhanced the uptake of substrates, which could not only improve cell growth but also stimulate
γ-PGA production. Moreover, it was also found that glycerol could effectively regulate molecular weight between 2.43 ± 0.07 × 106 and 1.42 ± 0.05 × 106 Da with the concentration ranging from 0 to 60 g/l. This was the first time to discover such contribution of glycerol on
γ-PGA production in Bacillus genus. And the effects of glycerol on molecular weight of γ-PGA would be developed to be an approach for the regulation of
microbial γ-PGA chain length, which is of practical importance for future commercial development of this polymer. 相似文献
12.
Liu GQ Xiao HX Wang XL Zhao Y Zhang YG Ren GP 《Applied biochemistry and biotechnology》2011,165(1):87-97
The medicinal fungus Ganoderma lucidum was inoculated into the media with and without supplementation of medicinal insect extracts to screen stimulators from Chinese
medicinal insects for mycelial growth and triterpenoids production in submerged fermentation. The methanol and ether extracts
of the tested insects had no significant stimulatory effect on the mycelial biomass production (P > 0.05), and those of H. remigator and Mylabris phalerata markedly inhibited the mycelial growth. However, the ether extract of Catharsius molossus at a concentration of 200 mg l−1 led to a significant increase in triterpenoids concentration from 231.7 ± 9.77 to 313.7 ± 10.6 mg l−1 (P < 0.01). Analysis of fermentation kinetics of G. lucidum suggests that glucose concentration in the extract of C. molossus-added group decreased more quickly as compared to the control group from day 2 to day 7 of fermentation process, while the
triterpenoids biosynthesis was promoted at the same culture period. However, the culture pH profile was not affected by the
addition of the extract. Chemical study of the extract show that cis-9,10-methylenehexadecanoic acid (9,10-MEA) and hexadecanoic acid (especially 9,10-MEA) were the key active compounds of the
extract responsible for the stimulatory effect on the triterpenoids production. 相似文献
13.
In order to reduce of the manufacturing cost of bacterial cellulose (BC), BC production by Acetobacter sp. V6 was investigated in shaking culture using molasses and corn steep liquor (CSL) as the sole carbon and nitrogen sources,
respectively. The highest BC production was obtained with Ca3(PO4)2-treated molasses. Maximum BC yield (2.21 ± 0.04 g/l) was obtained at 5% (w/v) total sugar in molasses. In improved medium containing molasses and CSL, BC production was observed in the medium after
1 day of incubation and increased rapidly thereafter with maximum yield (3.12 ± 0.03 g/l) at 8 days. This value was approximately
twofold higher than the yield in the complex medium. Physical properties of BC from the complex and molasses media were studied
using Fourier-transform infrared (FT-IR) spectroscopy and X-ray diffractometer. By FT-IR, all the BC were found to be of cellulose
type І, the same as typical native cellulose. The relative crystallinity of BC produced in the complex and molasses media
were 83.02 and 67.27%, respectively. These results suggest that molasses and CSL can be useful low-cost substrates for BC
production by Acetobacter sp. V6 without supplementation with expensive nitrogen complexes such as yeast extract and polypeptone, leading to the reduction
in the production costs. 相似文献
14.
The Effect of pH on Continuous Biohydrogen Production from Swine Wastewater Supplemented with Glucose 总被引:1,自引:0,他引:1
Yecong Li Jun Zhu Xiao Wu Curtis Miller Liang Wang 《Applied biochemistry and biotechnology》2010,162(5):1286-1296
The effect of pH on hydrogen production from liquid swine manure supplemented with glucose by a mixed culture of fermentative
bacteria in an anaerobic sequencing batch reactor was evaluated in this study. At 37 ± 1 °C, five pH values ranging from 4.7
to 5.9 at an increment of 0.3 were tested at a hydraulic retention time (HRT) of 16 h. The results showed that at this HRT,
the optimal pH for hydrogen production was 5.0, under which the biogas comprised 33.57 ± 5.65% of hydrogen with a production
rate of 8.88 ± 2.94 L-H2/day and a yield of 1.48 ± 0.49 L-H2/L liquid swine manure. The highest biomass concentration, highest butyric acid to acetic acid ratio, lowest propionic acid
concentration, and the best stability were all found at pH 5.0, while the highest CH4 productivity was found at pH 5.9. For efficient hydrogen production, oxygen content should be controlled under 2%, beyond
which an inverse linear relationship (R
2 = 0.986) was observed. 相似文献
15.
S. Shanmughapriya G. Seghal Kiran Joseph Selvin T. Anto Thomas C. Rani 《Applied biochemistry and biotechnology》2010,162(3):625-640
Marinobacter sp. (MSI032) isolated from the marine sponge Dendrilla nigra was optimized for the production of extracellular cellulolytic enzyme (CMCase) by submerged fermentation. Initial experiments
showed that the culture medium containing 1% maltose as carbon source and 1% peptone and casein as nitrogen source supported
maximal enzyme production at 27 °C and at a pH of 9.0. Further optimization carried out showed the maximal enzyme production
was supported by the presence of 2% NaCl and 10 mM Zn2+ ions in the production media. The production of enzyme cellulase occurred at 48 h of incubation which proved the importance
of this strain for cellulase production in large scale. Further, the enzyme was purified to 12.5-fold with a 37% yield and
a specific activity of 2,548.75 U/mg. The purified enzyme displayed maximum activity at mesophilic temperature (27–35 °C)
and at a broad pH range with optimal activity at pH 9.0. The purified enzyme was stable even at a higher alkaline pH of 12.0
which is greater than the pH stability that has not been reported in any of the cellulolytic isolates studied so far. Thus,
from the present study, it is crucial that, instead of exploring the thermophilic resource that is limited in natural environments,
the mesophilic bacteria that occurs commonly in nature can be added up to the database of cellulolytic bacteria. Thus, it
is possible that a wide diversity of mesophilic bacteria associated with marine sponges opens up a new doorstep for the degradation
of cellulosic waste material for the production of liquid fuels. This is the first report elucidating the prospects of sponge-associated
marine bacterium for the production of extracellular alkaline cellulase. 相似文献
16.
Jun Yao Hong Xu Ningning Shi Xin Cao Xiaohai Feng Sha Li Pingkai Ouyang 《Applied biochemistry and biotechnology》2010,160(8):2332-2341
Bacillus subtilis NX-2 produces γ-polyglutamic acid (γ-PGA) when using glucose and l-glutamate as carbon sources. The conversion of carbon sources into γ-PGA was analyzed with the 13C-NMR method after enriching the media with 13C-labeled glucose. The results showed that the percentage of γ-PGA monomers derived from glucose was relatively low, approximately
6% and 9%, respectively, with an initial glucose concentration of 30 and 40 g L−1. It was concluded that glucose was utilized mainly as the growth-limiting substrate for cell growth and supplied the required
energy during γ-PGA biosynthesis, while l-glutamate was preferred as the main substrate for γ-PGA formation. To achieve an efficient conversion of l-glutamate and enhance the γ-PGA production, a fed-batch culture was proposed by feeding of glucose. By this method, supplied
l-glutamate (40 g L−1) was completely depleted, and γ-PGA yield was attained 42 g L−1. 相似文献
17.
Sensitive fluorescent probes for determination of hydrogen peroxide and glucose based on enzyme-immobilized magnetite/silica nanoparticles 总被引:2,自引:0,他引:2
Qing Chang Lihua Zhu Guodong Jiang Heqing Tang 《Analytical and bioanalytical chemistry》2009,395(7):2377-2385
Sensitive fluorescent probes for the determination of hydrogen peroxide and glucose were developed by immobilizing enzyme
horseradish peroxidase (HRP) on Fe3O4/SiO2 magnetic core–shell nanoparticles in the presence of glutaraldehyde. Besides its excellent catalytic activity, the immobilized
enzyme could be easily and completely recovered by a magnetic separation, and the recovered HRP-immobilized Fe3O4/SiO2 nanoparticles were able to be used repeatedly as catalysts without deactivation. The HRP-immobilized nanoparticles were able
to activate hydrogen peroxide (H2O2), which oxidized non-fluorescent 3-(4-hydroxyphenyl)propionic acid to a fluorescent product with an emission maximum at 409 nm.
Under optimized conditions, a linear calibration curve was obtained over the H2O2 concentrations ranging from 5.0 × 10−9 to 1.0 × 10−5 mol L−1, with a detection limit of 2.1 × 10−9 mol L−1. By simultaneously using glucose oxidase and HRP-immobilized Fe3O4/SiO2 nanoparticles, a sensitive and selective analytical method for the glucose detection was established. The fluorescence intensity
of the product responded well linearly to glucose concentration in the range from 5.0 × 10−8 to 5.0 × 10−5 mol L−1 with a detection limit of 1.8 × 10−8 mol L−1. The proposed method was successfully applied for the determination of glucose in human serum sample. 相似文献
18.
Chun-yan Xie Zhen-xin Gu Gong-jian Fan Fei-rong Gu Yong-bin Han Zhi-gang Chen 《Applied biochemistry and biotechnology》2009,158(2):483-492
The submerged fermentation of Cordyceps militaris for cordycepin production and mycelial growth was investigated in this study. Three natural materials of brown rice paste
(BRP), beerwort (B), and soybean meal juice (SMJ) were used for fermentation of C. militaris in shaking flasks. The effects of the ratio of three natural materials on dry mycelium weight (DMW) and on cordycepin yield
(CY) were analyzed. D-Optional mixture design was used to optimize the ratio of these materials. Compared with the signal
culture, the higher mycelial growth and cordycepin production were obtained in mixture. The analysis of Design Expert 6.0
indicated that BRP, B, and SMJ very significantly influenced (P < 0.001) DMW and CY of C. militaris, respectively. The highest DMW (18.96 g/l) and CY (2.17 mg/g) were both obtained at a ratio of 53:6:42. The experiments’
results indicated that the above mixture of these natural materials by D-optional mixture design can be used as a proper medium
for the growth of mycelium and the production of cordycepin. 相似文献
19.
Bezerra RA Rodrigues JA Ratusznei SM Canto CS Zaiat M 《Applied biochemistry and biotechnology》2011,165(1):347-368
Currently, there is an increasing demand for the production of biodiesel and, consequently, there will be an increasing need
to treat wastewaters resulting from the production process of this biofuel. The main objective of this work was, therefore,
to investigate the effect of applied volumetric organic load (AVOL) on the efficiency, stability, and methane production of
an anaerobic sequencing batch biofilm reactor applied to the treatment of effluent from biodiesel production. As inert support,
polyurethane foam cubes were used in the reactor and mixing was accomplished by recirculating the liquid phase. Increase in
AVOL resulted in a drop in organic matter removal efficiency and increase in total volatile acids in the effluent. AVOLs of
1.5, 3.0, 4.5 and 6.0 g COD L−1 day−1 resulted in removal efficiencies of 92%, 81%, 67%, and 50%, for effluent filtered samples, and 91%, 80%, 63%, and 47%, for
non-filtered samples, respectively, whereas total volatile acids concentrations in the effluent amounted to 42, 145, 386 and
729 mg HAc L−1, respectively. Moreover, on increasing AVOL from 1.5 to 4.5 g COD L−1 day−1 methane production increased from 29.5 to 55.5 N mL CH4 g COD−1. However, this production dropped to 36.0 N mL CH4 g COD−1 when AVOL was increased to 6.0 g COD L−1 day−1, likely due to the higher concentration of volatile acids in the reactor. Despite the higher concentration of volatile acids
at the highest AVOL, alkalinity supplementation to the influent, in the form of sodium bicarbonate, at a ratio of 0.5–1.3 g NaHCO3 g CODfed−1, was sufficient to maintain the pH near neutral and guarantee process stability during reactor operation. 相似文献
20.
Mohamad Faizal Ibrahim Suraini Abd-Aziz Mohamad Nafis Abdul Razak Lai Yee Phang Mohd Ali Hassan 《Applied biochemistry and biotechnology》2012,166(7):1615-1625
Acetone–butanol–ethanol (ABE) production from renewable resources has been widely reported. In this study, Clostridium butyricum EB6 was employed for ABE fermentation using fermentable sugar derived from treated oil palm empty fruit bunch (OPEFB). A
higher amount of ABE (2.61 g/l) was produced in a fermentation using treated OPEFB as the substrate when compared to a glucose
based medium that produced 0.24 g/l at pH 5.5. ABE production was increased to 3.47 g/l with a yield of 0.24 g/g at pH 6.0.
The fermentation using limited nitrogen concentration of 3 g/l improved the ABE yield by 64%. The study showed that OPEFB
has the potential to be applied for renewable ABE production by C. butyricum EB6. 相似文献