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1.
Myung-Hwan Kim Wa Gao Chung-Han Chung Jin-Woo Lee 《Biotechnology and Bioprocess Engineering》2017,22(2):142-149
The optimal conditions for mass production of carboxymethylcellulase (CMCase) by E. coli JM109/A-68 were investigated and compared with other E. coli JM109 recombinants producing CMCase. The optimal agitation speed and aeration rate for cell growth of E. coli JM109/A- 68 were 500 rpm and 0.50 vvm in a 7 L bioreactor, whereas those for production of CMCase were 416 rpm and 0.95 vvm. The optimal vessel pressures for cell growth as well as production of CMCase in a 100 L bioreactor were 0.04 MPa. The maximal production of CMCase by E. coli JM109/A-68 under the optimized conditions in a 100 L bioreactor was 11.0 times higher than its wild type, B. velezensis A-68. Optimal conditions for mass production of CMCase by recombinants were different from those for wild strains. The higher production of CMCase by E. coli JM109/A-68 and other recombinant of E. coli seemed to result from its higher cell growth under the optimal conditions for dissolved oxygen and its mixed-growth associated production pattern compared to the growthassociated production of B. velezensis A-68. 相似文献
2.
A gene encoding carboxymethylcellulase (CMCase) of Bacillus velezensis A-68 had been cloned in Escherichia coli JM109. Based on productivity and economic aspect, rice bran and ammonium chloride were chosen to be optimal carbon and nitrogen sources for production of CMCase by E. coli JM109/A-68. The optimal conditions for rice bran, ammonium chloride, and initial pH of medium for production of CMCase were established by the response surface methodology (RSM). The concentrations of four salts in the medium, K2HPO4, NaCl, MgSO4·7H2O, and (NH4)2SO4, for production of CMCase also were optimized. The optimal temperatures for cell growth and production of CMCase were 37°C. The maximal production of CMCase by E. coli JM109/A-68 was 880.2 U/mL, which was 10.5 time higher than its wild type, B. velezensis A-68. The production of CMCase by E. coli JM109/A-68 was compared with that by B. velezensis A-68 in a 100 L pilot-scale bioreactor under the optimized conditions. The production of CMCase by E. coli JM109/A-68 was found to be the mixed-growth associated unlike the growthassociated production of CMCase by B. velezensis A-68. 相似文献
3.
Hye-Jin Kim You-Jung Lee Wa Gao Chung-Han Chung Chang-Woo Son Jin-Woo Lee 《Biotechnology and Bioprocess Engineering》2011,16(3):542-548
The optimal conditions for the production of cellulases by a marine bacterium, Psychrobacter aquimaris LBH-10, were established and their effects were compared using orthogonal array experiments based on the Taguchi method.
The optimal conditions of rice bran, peptone and initial pH for the production of avicelase and CMCase by P. aquimaris LBH-10 were 50.0, 3.0, and 8.0 g/L, respectively, whereas those for filter paperase (FPase) were 100.0, 3.0, and 8.0 g/L,
respectively. Rice bran was found to be the most important factor for the production of cellulases based on the calculated
percentage of participation P (%) from an analysis of the variance (ANOVA). The optimal temperature for the cell growth of P. aquimaris LBH-10 was 25°C, whereas that for the production of avicelase, CMCase and FPase was 30°C. The optimal agitation speed and
aeration rate for cell growth was 400 rpm and 1.5 vvm, respectively, whereas those for the production of CMCase were 300 rpm
and 1.0 vvm, respectively. Aeration was found to be more important for cell growth and CMCase production than agitation. The
maximum production of avicelase, CMCase and FPase in a 100 L bioreactor for 72 h under optimized conditions was 83.2, 388.7,
and 75.4 U/mL, respectively. 相似文献
4.
A gene encoding the carboxymethylcellulase (CMCase) of a marine bacterium, Bacillus subtilis subsp. subtilis A-53, was cloned in Escherichia coli JMB109 and the recombinant strain was named as E. coli JMB109/A-53. The optimal conditions of rice bran, ammonium chloride, and initial pH of the medium for cell growth, extracted by Design Expert Software based on response surface methodology, were 100.0 g/l, 7.5 g/l, and 7.0, respectively, whereas those for production of CMCase were 100.0 g/l, 7.5 g/l, and 8.0. The optimal temperatures for cell growth and the production of CMCase by E. coli JM109/A-53 were found to be and 40 and 35 °C, respectively. The optimal agitation speed and aeration rate of a 7 l bioreactor for cell growth were 400 rpm and 1.5 vvm, whereas those for production of CMCase were 400 rpm and 0.5 vvm. The optimal inner pressure for cell growth was 0.06 MPa, which was the same as that for production of CMCase. The production of CMCase by E. coli JM109/A-53 under optimized conditions was 880.2 U/ml, which was 2.9 times higher than that before optimization. In this study, rice bran and ammonium chloride were developed as carbon and nitrogen source for production of CMCase by a recombinant E. coli JM109/A-53 and the productivity of E. coli JM109/A-53 was 5.9 times higher than that of B. subtilis subp. subtilis A-53. 相似文献
5.
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
6.
An Escherichia coli strain, JM109, was successfully engineered into an efficient hyaluronic acid (HA) producer by co-expressing the only known
class-II HA synthase from a Gram-negative bacterium (Pasteurella multocida) and uridine diphosphate-glucose dehydrogenase from E. coli K5 strain. The engineered strain produced about 0.5 g/L HA in shake flask culture and about 2.0–3.8 g/L in a fed-batch fermentation
process in a 1-L bioreactor. The sharp increase in viscosity associated with HA accumulation necessitated pure oxygen supplement
to maintain fermentation in aerobic regime. Precursor supply during HA synthesis was probed by glucosamine supplement, which
shortens biosynthesis pathway and eliminates one step requiring ATP. HA synthesis was increased with glucosamine supplement
from 2.7 to 3.7 g/L (37%), which was mirrored with a concomitant 42% decrease in pure oxygen input, suggesting a close connection
between energy metabolism and precursor supply. Decoupling HA synthesis from cell growth by using fosfomycin (an inhibitor
for cell wall synthesis) led to a 70% increase in HA synthesis, suggesting detrimental effects on HA synthesis from cell growth
via precursor competition. This study demonstrates a potentially viable process for HA based on a recombinant E. coli strain. In addition, the precursor supply limitation identified in this study suggests new engineering targets in subsequent
metabolic engineering efforts. 相似文献
7.
E. coli JM109?envC?nlpD deleted with genes envC and nlpD responsible for degrading peptidoglycan (PG) led to long filamentous cell shapes. When cell fission ring location genes minC and minD of Escherichia coli were deleted, E. coli JM109?minCD changed the cell growth pattern from binary division to multiple fissions. Bacterial morphology can be further engineered by overexpressing sulA gene resulting in inhibition on FtsZ, thus generating very long cellular filaments. By overexpressing sulA in E. coli JM109?envC?nlpD and E. coli JM109?minCD harboring poly(3-hydroxybutyrate) (PHB) synthesis operon phbCAB encoded in plasmid pBHR68, respectively, both engineered cells became long filaments and accumulated more PHB compared with the wild-type. Under same shake flask growth conditions, E. coli JM109?minCD (pBHR68) overexpressing sulA grown in multiple fission pattern accumulated approximately 70 % PHB in 9 g/L cell dry mass (CDM), which was significantly higher than E. coli JM109?envC?nlpD and the wild type, that produced 7.6 g/L and 8 g/L CDM containing 64 % and 51 % PHB, respectively. Results demonstrated that a combination of the new division pattern with elongated shape of E. coli improved PHB production. This provided a new vision on the enhanced production of inclusion bodies. 相似文献
8.
Toluene dioxygenase (TDO) catalyzes asymmetric cis-dihydroxylation of aromatic compounds. To achieve high efficient biotransformation of benzene to benzene cis-diols, Pseudomonas putida KT2442, Pseudomonas stutzeri 1317, and Aeromonas hydrophila 4AK4 were used as hosts to express TDO gene tod. Plasmid pSPM01, a derivative of broad-host plasmid pBBR1MCS-2 harboring tod from plasmid pKST11, was constructed and introduced into the above three strains. Their abilities to catalyze the biotransformation
of benzene to benzene cis-diols, namely, cis-3,5-cyclohexadien-1,2-diols abbreviated as DHCD, were examined. In shake-flask cultivation under optimized culture media
and growth condition, benzene cis-diols production by recombinant P. putida KT2442 (pSPM01), P. stutzeri 1317 (pSPM01), and A. hydrophila 4AK4 (pSPM01) were 2.68, 2.13, and 1.17 g/l, respectively. In comparison, Escherichia coli JM109 (pSPM01) and E. coli JM109 (pKST11) produced 0.45 and 0.53 g/l of DHCD, respectively. When biotransformation was run in a 6-l fermenter, DHCD
production in P. putida KT2442 (pSPM01) was approximately 60 g/l; this is the highest DHCD production yield reported so far. 相似文献
9.
Qiang Li Dan Wang Yong Wu Maohua Yang Wangliang Li Jianmin Xing Zhiguo Su 《Journal of microbiology (Seoul, Korea)》2010,48(3):290-296
Succinic acid is one of the platform compounds and its production via natural feedstocks has drawn worldwide concerns. To
evaluate the inhibitory effects of fermentation products on the growth of Actinobacillus succinogenes 130ZT and Escherichia coli NZN111, AFP111, BL21, fermentations with addition of individual products in medium were carried out. The cell growth was
inhibited when the concentrations of formate, acetate, lactate, and succinate were at range of 8.8–17.6 g/L, 10–40 g/L, 9–18
g/L, and 10–80 g/L, respectively. For these two species of bacteria, E. coli was more resistant to acid products than A. succinogenes, while both endured succinate rather than by-products. As a result of end product inhibition, succinate production yield
by A. succinogenes decreased from 1.11 to 0.49 g/g glucose. Logistic and Monod mathematical models were presented to simulate the inhibition
kinetics. The Logistic model was found more suitable for describing the overall synergistic inhibitory effects. 相似文献
10.
He Jun Yu Bing Zhang Keying Ding Xuemei Chen Daiwen 《Indian journal of microbiology》2009,49(2):188-195
The strain of Trichoderma reesei Rut C-30 was subjected to mutation after treatment with N-methyl-N′-nitro-N-nitrosoguanidine (NG) for 6 h followed by UV irradiation for 15 min. Successive mutants showed enhanced cellulase production,
clear hydrolysis zone and rapid growth on Avicel-containing plate. Particularly, the mutant NU-6 showed approximately two-fold
increases in activity of both FPA and CMCase in shake flask culture when grown on basal medium containing peptone (1%) and
wheat bran (1%). The enzyme production was further optimized using eight different media. When a mixture of lactose and yeast
cream was used as cellulase inducer, the mutant NU-6 yielded the highest enzyme and cell production with a FPase activity
of 6.2 U ml−1, a CMCase activity of 54.2 U ml−1, a β-glucosidase activity of 0.39 U ml−1, and a fungal biomass of 12.6 mg ml−1. It deserved noting that the mutant NU-6 also secreted large amounts of xylanases (291.3 U ml−1). These results suggested that NU-6 should be an attractive producer for both cellulose and xylanase production. 相似文献
11.
12.
M. Subhosh Chandra Buddolla Viswanath B. Rajasekhar Reddy 《Indian journal of microbiology》2007,47(4):323-328
The production of cellulolytic enzymes by Aspergillus niger on lignocellulosic substrates groundnut fodder, wheat bran, rice bran and sawdust in solid state fermentation in a laboratory
scale was compared. Czapek Dox liquid broth amended with cellulose (0.5%) was used to moisten lignocellulosic solid supports
for cultivation of Aspergillus niger. The production of filter paperase, carboxymethyl cellulase and -glucosidase were monitored at daily intervals for 5 days.
The peak production of the enzymes occurred within 3 days of incubation. Among solid supports used in the study, wheat bran
was the best solid matrix followed by groundnut fodder in production of cellulolytic enzymes in solid state fermentation.
Groundnut fodder supported significant production of FPase (2.09 FPU/g), CMCase (1.36 U/g) and -glucosidase activity (0.0117
U/g) in solid state fermentation. Considerable secretion of protein (5.10 mg/g) on groundnut fodder at peak time interval
1st day of incubation was recorded. 相似文献
13.
Farzana Ashrafi Neela L. Nonaka M. H. Rahman S. Suzuki 《World journal of microbiology & biotechnology》2009,25(6):1095-1101
The transferability of the tetracycline (TC) resistance gene tet(M) from marine bacteria to human enteric bacteria was examined by a filter-mating method. Vibrio spp., Lactococcus garvieae, Bacillus spp., Lactobacillus sp., and Paenibacillus sp. were used as donors, and Escherichia coli JM109 and Enterococcus faecalis JH2-2 were used as recipients. The combination of Vibrio spp. and E. coli resulted in 5/68 positive transconjugants with a transfer rate of 10−7 to 10−3; however, no transfer was observed with E. faecalis. In case of L. garvieae and E. faecalis, 6/6 positive transconjugants were obtained with a transfer rate of 10−6 to 10−5; however, no transfer was observed with E. coli. The tet(M) gene of Bacillus, Lactobacillus, and Paenibacillus were not transferred to either E. coli or E. faecalis. tet(M) transfer was confirmed in positive E. coli and E. faecalis transconjugants by polymerase chain reaction (PCR) and Southern hybridization. All the donor strains did not harbor plasmids,
while they all harbored transposon Tn916. In the transconjugants, the transposon was not detected by PCR, suggesting the possible transfer of tet(M) from the marine bacterial chromosome to the recipient chromosome. This is the first report to show that tet(M) can be transferred from marine bacteria to human enteric bacteria in a species-specific manner. 相似文献
14.
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
15.
The phoA expression system is an efficient one and is successfully used in foreign gene expression. In a previous study, it was found
that pH during the expression phase had a significant effect on extracellular hEGF production under control of the phoA promoter by Escherichia coli DA19, an acetate-tolerant strain of E. coli DH5α, in a chemically defined medium, but the level of hEGF production was only 75.5 mg/L. E. coli DB15 is another acetate tolerant mutant of DH5α. In the present study, production of hEGF under control of the phoA promoter by DB15 was further investigated. When transition from the growth phase, where phosphate was abundant, to the expression
phase where phosphate was limited, was performed based on cell density, the extracellular hEGF reached 165 mg/L, twice that
when transition was based on dissolved oxygen. Furthermore, adding 0.22 g/L of CaCl2 during the growth phase, further increased hEGF production to 228 mg/L, which is 3-fold the level produced by DA19 (pAET-8)
cultured in the same medium. 相似文献
16.
Piyachai Premvaranon Suchada Vearasilp Sa-nguansak Thanapornpoonpong Dumnern Karladee Shela Gorinstein 《Biologia》2011,66(6):1074-1081
The aim of this investigation was to improve in vitro the technique of production of double haploid in Indica hybrid rice by combining anther culture, hormone shock and doubling chromosome. It was discussed how to avoid somaclonal
variation during culturing and to reduce the time of this process. The anthers of KDML 105 × SPR 1 (Indica × Indica) were cultured in Linsmaier and Skoog (LS) medium, which contained nutrients, growth regulators [(2,4,-dichlorophenoxy acetic
acid (2,4-D) and naphthalene acetic acid (NAA)] and organic compounds, and then subcultured by inducing embryo-like structure
(ELS) LS media. During 4 weeks used LS media supplemented with 10 μM KNO3 + 2 mg/L 2,4-D + 2 mg/L NAA + 20% coconut water + 1 mg/L of activated charcoal had induced high embryogenic frequent callus
with length of 4–5 mm. The supplementation of 0.2 g/L colchicine and 100 μM 2,4-D was the most efficient in LS media. Over
70% of viable double haploid ELS were produced in 8 weeks and subcultured only twice compared with conventional anther which
takes more than 12 weeks. This new technique can therefore be applied to rice in order in shorten time to produce higher number
of double haploid plantlets. 相似文献
17.
18.
Xiao-Xing Wei Zhen-Yu Shi Mei-Qing Yuan Guo-Qiang Chen 《Applied microbiology and biotechnology》2009,82(4):703-712
Nine anaerobic promoters were cloned and constructed upstream of PHB synthesis genes phbCAB from Ralstonia eutropha for the micro- or anaerobic PHB production in recombinant Escherichia coli. Among the promoters, the one for alcohol dehydrogenase (P
adhE
) was found most effective. Recombinant E. coli JM 109 (pWCY09) harboring P
adhE
and phbCAB achieved a 48% PHB accumulation in the cell dry weight after 48 h of static culture compared with only 30% PHB production
under its native promoter. Sixty-seven percent PHB was produced in the dry weight (CDW) of an acetate pathway deleted (Δpta deletion) E. coli JW2294 harboring the vector pWCY09. In a batch process conducted in a 5.5-l NBS fermentor containing 3 l glucose LB medium,
E. coli JW2294 (pWCY09) grew to 7.8 g/l CDW containing 64% PHB after 24 h of microaerobic incubation. In addition, molecular weight
of PHB was observed to be much higher under microaerobic culture conditions. The high activity of P
adhE
appeared to be the reason for improved micro- or anaerobic cell growth and PHB production while high molecular weight contributed
to the static culture condition. 相似文献
19.
A genetically engineered strain of Escherichia coli JM109 harboring the isopropanol-producing pathway consisting of five genes encoding four enzymes, thiolase, coenzyme A (CoA)
transferase, acetoacetate decarboxylase from Clostridium acetobutylicum ATCC 824, and primary–secondary alcohol dehydrogenase from C. beijerinckii NRRL B593, produced up to 227 mM of isopropanol from glucose under aerobic fed-batch culture conditions. Acetate production
by the engineered strain was approximately one sixth that produced by a control E. coli strain bearing an expression vector without the clostridial genes. These results demonstrate a functional isopropanol-producing
pathway in E. coli and consequently carbon flux from acetyl-CoA directed to isopropanol instead of acetate. This is the first report on isopropanol
production by genetically engineered microorganism under aerobic culture conditions. 相似文献
20.
The gene encoding malate dehydrogenase (MDH) was overexpressed in a pflB ldhA double mutant of Escherichia coli, NZN111, for succinic acid production. With MDH overexpression, NZN111/pTrc99A-mdh restored the ability to metabolize glucose anaerobically and 0.55 g/L of succinic acid was produced from 3 g/L of glucose
in shake flask culture. When supplied with 10 g/L of sodium bicarbonate (NaHCO3), the succinic acid yield of NZN111/pTrc99A-mdh reached 1.14 mol/mol glucose. Supply of NaHCO3 also improved succinic acid production by the control strain, NZN111/pTrc99A. Measurement of key enzymes activities revealed
that phosphoenolpyruvate (PEP) carboxykinase and PEP carboxylase in addition to MDH played important roles. Two-stage culture
of NZN111/pTrc99A-mdh was carried out in a 5-L bioreactor and 12.2 g/L of succinic acid were produced from 15.6 g/L of glucose. Fed-batch culture
was also performed, and the succinic acid concentration reached 31.9 g/L with a yield of 1.19 mol/mol glucose. 相似文献