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1.
Li Zhao Jinping Lin Hualei Wang Jingli Xie Dongzhi Wei 《Bioprocess and biosystems engineering》2015,38(12):2487-2495
In this work, a two-step process was developed for the production of 3-hydroxypropionic acid from glycerol. In the first step, glycerol was converted to 1,3-propanediol by Klebsiella pneumonia. In the second step, the 1,3-propanediol was converted into 3-hydroxypropionic acid by Gluconobacter oxydans. In a 7.0 L bioreactor, the whole process took 54 h, consumed 480 g glycerol and produced 242 g 3-hydroxypropionic acid. The conversion rate of glycerol to 3-hydroxypropionic acid was 50.4 % (g g?1). The final concentration of 3-hydroxypropionic acid arrived 60.5 g L?1. The process was effective for 3-HP production from glycerol and it might provide a new approach to the biosynthesis of 3-HP from a cheap starting material. Moreover, in this paper, it was first reported that the by-product of 3-hydroxypropionic acid production from 1,3-propandeiol was acrylic acid. 相似文献
2.
White rot fungi are a promising option to treat recalcitrant organic molecules, such as lignin, polycyclic aromatic hydrocarbons,
and textile dyes, because of the lignin-modifying enzymes (LMEs) they secrete. Because knowledge of the kinetic parameters
is important to better design and operate bioreactors to cultivate these fungi for degradation and/or to produce LME(s), these
parameters were determined using Trametes versicolor ATCC 20869 (ATCC, American Type Culture Collection) in a magnetic stir bar reactor. A complete set of kinetic data has not
been previously published for this culture. Higher than previously reported growth rates with high laccase production of up
to 1,385 U l−1 occurred during growth without or glucose limitation. The maximum specific growth rate averaged 0.94 ± 0.23 day−1, whereas the maximum specific substrate consumption rates for glucose and ammonium were 3.37 ± 1.16 and 0.15 ± 0.04 day−1, respectively. The maximum specific oxygen consumption rate was 1.63 ± 0.36 day−1. 相似文献
3.
A novel protein from Gluconobacter oxydans DSM2003 which shows 60–70% similarity with members of aldo–keto reductase (AKR) superfamily was overexpressed in Escherichia coli BL21 (DE3) and purified by one step affinity chromatography with a Ni-NTA agarose column. The recombinant protein (named
GOX0644) consists of 279 amino acids with an apparent molecular mass of 32 kDa in the soluble fraction, and the gene sequence
encoding the protein GOX0644 is 100% identical to the ORF of gox0644 in G. oxydans 621H (DSM2343). For a detailed analysis of its enzymatic activity, the substrate specificity of the recombinant protein GOX0644
was determined. With NADPH as a cofactor, GOX0644 exhibited better activity to aromatic aldehydes, especially o-chlorobenzaldehyde, compared to aliphatic aldehydes. It showed almost no activity toward glyceraldehyde, xylose, glucose,
and ketones. The protein was unable to oxidize primary- or secondary alcohols. Based on these results, GOX0644 was defined
as a novel NADPH-dependent aldehyde reductase. Kinetic parameters of the protein and the dependence of its activity on temperature
and pH were also determined. 相似文献
4.
5.
6.
An optimized repeated-fed-batch fermentation process for the synthesis of dihydroxyacetone (DHA) from glycerol utilizing Gluconobacter oxydans is presented. Cleaning, sterilization, and inoculation procedures could be reduced significantly compared to the conventional fed-batch process. A stringent requirement was that the product concentration was kept below a critical threshold level at all times in order to avoid irreversible product inhibition of the cells. On the basis of experimentally validated model calculations, a threshold value of about 60 kg m-3 DHA was obtained. The innovative bioreactor system consisted of a stirred tank reactor combined with a packed trickle-bed column. In the packed column, active cells could be retained by in situ immobilization on a hydrophilized Ralu-ring carrier material. Within 17 days, the productivity of the process could be increased by 75% to about 2.8 kg m-3 h-1. However, it was observed that the maximum achievable productivity had not been reached yet.Abbreviations
K
O
Monod half saturation constant of dissolved oxygen (kg m-3)
-
K
S
Monod half saturation constant of substrate glycerol (kg m-3)
-
O
Dissolved oxygen concentration (kg m-3)
-
P
Product concentration (kg m-3)
-
P
crit
Critical product concentration constant (kg m-3)
-
S
Substrate concentration (kg m-3)
-
t
Time (s)
-
X
Biomass concentration (dry weight) (kg m-3)
-
Y
P/S
Yield coefficient of product from substrate
-
Y
X/S
Yield coefficient of biomass from substrate
-
Growth dependent specific production rate constant (kg m-3)
-
Growth independent specific production rate constant (s-1)
-
Specific growth rate (s-1)
-
max
Maximum specific growth rate constant (s-1) 相似文献
7.
Objectives
To investigate the roles of adhS, which encodes the AdhS subunit of membrane-bound alcohol dehydrogenase (mADH) in Gluconobacter oxydans DSM2003, and to rationally improve mADH activity.Results
adhS was identified and overexpressed in G. oxydans DSM2003. Its overexpression promoted the AdhA subunit which serves as the primary dehydrogenase transfer from the periplasmic space to the periplasmic surface of the membrane thereby increasing the amount of active mADH and thus enhancing mADH activity up to 1.96-fold. The increased mADH activity significantly altered product selectivity (glyceric acid/dihydroxyacetone) during glycerol oxidation and increased the glyceric acid production by 7.6-fold. By comparison, overexpression of adhS and adhABS was equally effective in increasing the mADH activity and glyceric acid production.Conclusions
adhS overexpression effectively improved mADH activity, indicating that for mADH, adhS might be a limiting component. The findings provide a guide for the efficient application of Gluconobacter spp. in hydroxy acid production.8.
Guodong Wei Xuepeng Yang Tula Gan Wenyu Zhou Jinping Lin Dongzhi Wei 《Journal of industrial microbiology & biotechnology》2009,36(8):1029-1034
Gluconobacter oxydans has a lower biomass yield. Uniform design (UD) was applied to determine the optimum composition of the critical media and
their mutual interactions for increased biomass yield of Gluconobacter oxydans DSM 2003 in shake flasks. Fed-batch fermentation process for biomass was optimized in a 3.7-l fermentor. By undertaking a
preliminary and improved fed-batch fermentation-process strategy, a cell density of 6.0 g/l (DCW) was achieved in 22 h and
14.1 g/l (DCW) in 35 h, which is the highest cell density of G. oxydans produced thus far in a 3.7-l bioreactor. The biomass production was increased by 135% compared with that using the original
cultivation strategy. Bioconversion of ethylene glycol to glycolic acid was catalyzed by the resting cells of G. oxydans DSM 2003, and conversion rate reached 86.7% in 48 h. In summary, the approach including high-density fermentation of G. oxydans DSM 2003 and bioconversion process was established and proved to be an effective method for glycolic acid production. 相似文献
9.
Pumin Nutaratat Nantana Srisuk Panarat Arunrattiyakorn Savitree Limtong 《Biotechnology and Bioprocess Engineering》2016,21(3):414-421
Indole-3-acetic acid (IAA) is a significant secondary metabolite that is the most important auxin of plant hormones. Production of IAA is considered to be a key trait to support plant growth. The improvement of IAA production by a basidiomycetous red yeast Rhodosporidium paludigenum DMKU-RP301 was investigated. Batch and fed-batch fermentation of R. paludigenum DMKU-RP301 were conducted in a 2 L stirred tank fermenter. Using batch fermentation, it was found that when cultivated at an agitation speed of 200 rpm and a 3 L/min aeration rate, this yeast produced IAA at its maximum level of 1,627.1 mg/L (9.7 mg/L/h). In fed-batch fermentation, a higher level of maximum IAA production than that found in batch fermentation was observed, i.e. 2,743.9 mg/L (25.4 mg/L/h). It is therefore suggested that fed-batch fermentation improves the efficiency of IAA production in terms of product concentration and IAA productivity. Moreover, yeast carotenoid production was also investigated using R. paludigenum DMKU-RP301, and found a maximum carotenoid production of 3.05 mg/L. 相似文献
10.
Gluconobacter oxydans that produces the cellulose was isolated. In order to confirm the chemical features of cellulose, various spectrophtometeric
analysis were carried out using electron microscopy, X-ray diffractogram, and CP/MAS13C NMR. The purified cellulose was found to be identical to that ofAcetobacter xylinum. For effective production of cellulose, the various carbon and nitrogen sources, mixture of calcium and magnesium ions, and
biotin concentration were investigated in flask cultures. Among the various carbon sources, glucose and sucrose were found
to be best for the production of cellulose, with maximum concentration of 2.41 g/L obtained when a mixture of 10 g/L of each
glucose and sucrose were used. With regard to the nitrogen sources, when 20 g/L of yeast extract was used, the maximum concentration
of bacterial cellulose was reached. The concentration of cellulose was increased with mixture of 2 mM of each Ca2+ and Mg2+. The optimum biotin concentration for the production of cellulose was in the range of 15 to 20 mg/L. At higher biotin concentration
(25–35 mg/L), the bacterial cellulose production was lower. 相似文献
11.
A. S. Vangnai W. Promden W. De-Eknamkul K. Matsushita H. Toyama 《Biochemistry. Biokhimii?a》2010,75(4):452-459
The quinate dehydrogenase (QDH) from Gluconobacter oxydans IFO3244 exhibits high affinity for quinate, suggesting its application in shikimate production. Nucleotide sequence analysis
of the qdh gene revealed a full-length of 2475-bp encoding an 824-amino acid protein. The qdh gene has the unusual TTG translation initiation codon. Conserved regions and a signature sequence for the quinoprotein family
were observed. Phylogenetic analysis demonstrated relatedness of QDH from G. oxydans to other quinate/shikimate dehydrogenases with the highest similarity (56%) with that of Acinetobacter calcoaceticus ADP1 and lower similarity (36%) with a membrane-bound glucose dehydrogenase of Escherichia coli. The function of the gene coding for QDH was confirmed by heterologous gene expression in pyrroloquinoline quinone-synthesizing
Pseudomonas putida HK5. 相似文献
12.
Konrad Kosciow Claudia Domin Paul Schweiger Uwe Deppenmeier 《Journal of industrial microbiology & biotechnology》2016,43(7):989-999
Gluconobacter (G.) oxydans strains have great industrial potential due to their ability to incompletely oxidize a wide range of carbohydrates. But there is one major limitation preventing their full production potential. Hydrolysis of polysaccharides is not possible because extracellular hydrolases are not encoded in the genome of Gluconobacter species. Therefore, as a first step for the generation of exoenzyme producing G. oxydans, a leaky outer membrane mutant was created by deleting the TolB encoding gene gox1687. As a second step the xynA gene encoding an endo-1,4-β-xylanase from Bacillus subtilis was expressed in G. oxydans ΔtolB. More than 70 % of the total XynA activity (0.91 mmol h?1 l culture?1) was detected in the culture supernatant of the TolB mutant and only 10 % of endoxylanase activity was observed in the supernatant of G. oxydans xynA. These results showed that a G. oxydans strain with an increased substrate spectrum that is able to use the renewable polysaccharide xylan as a substrate to produce the prebiotic compounds xylobiose and xylooligosaccharides was generated. This is the first report about the combination of the process of incomplete oxidation with the degradation of renewable organic materials from plants for the production of value-added products. 相似文献
13.
Lifei Chen Chunling Ma Ruiming Wang Jianlou Yang Haijie Zheng 《Biotechnology letters》2016,38(10):1769-1774
Objectives
To improve 1,3-propanediol (1,3-PD) production and reduce byproduct concentration during the fermentation of Klebsiella pneumonia.Results
Klebsiella. pneumonia 2-1ΔldhA, K. pneumonia 2-1ΔaldH and K. pneumonia 2-1ΔldhAΔaldH mutant strains were obtained through deletion of the ldhA gene encoding lactate dehydrogenase required for lactate synthesis and the aldH gene encoding acetaldehyde dehydrogenase involved in the synthesis of ethanol. After fed-batch fermentation, the production of 1,3-PD from glycerol was enhanced and the concentrations of byproducts were reduced compared with the original strain K. pneumonia 2-1. The maximum yields of 1,3-PD were 85.7, 82.5 and 87.5 g/l in the respective mutant strains.Conclusion
Deletion of either aldH or ldhA promoted 1,3-PD production in K. pneumonia.14.
Yu-Tze Horng Kai-Chih Chang Ta-Chung Chou Chung-Jen Yu Chih-Ching Chien Yu-Hong Wei Po-Chi Soo 《Journal of industrial microbiology & biotechnology》2010,37(7):707-716
1,3-Propanediol (1,3-PD) can be used for the industrial synthesis of a variety of compounds, including polyesters, polyethers,
and polyurethanes. 1,3-PD is generated from petrochemical and microbial sources. 1,3-Propanediol is a typical product of glycerol
fermentation, while acetate, lactate, 2,3-butanediol, and ethanol also accumulate during the process. Substrate and product
inhibition limit the final concentration of 1,3-propanediol in the fermentation broth. It is impossible to increase the yield
of 1,3-propanediol by using the traditional whole-cell fermentation process. In this study, dhaD and dhaK, the genes for glycerol dehydrogenase and dihydroxyacetone kinase, respectively, were inactivated by homologous recombination
in Klebsiella pneumoniae. The dhaD/dhaK double mutant (designated TC100), selected from 5,000 single or double cross homologous recombination mutants, was confirmed
as a double cross by using polymerase chain reaction. Analysis of the cell-free supernatant with high-performance liquid chromatography
revealed elimination of lactate and 2,3-butanediol, as well as ethanol accumulation in TC100, compared with the wild-type
strain. Furthermore, 1,3-propanediol productivity was increased in the TC100 strain expressing glycerol dehydratase and 1,3-PDO
dehydrogenase regulated by the arabinose PBAD promoter. The genetic engineering and medium formulation approaches used here should aid in the separation of 1,3-propanediol
from lactate, 2,3-butanediol, and ethanol and lead to increased production of 1,3-propanediol in Klebsiella pneumoniae. 相似文献
15.
Gluconobacter oxydans LMG 1489 was selected as the best strain for NAD(P)-dependent polyol dehydrogenase production. The highest enzyme activities were obtained when this strain was cultivated on a medium consisting of 30 g glycerol l–1, 7.2 g peptone l–1 and 1.8 g yeast extract l–1. Two D-fructose reducing, NAD-dependent intracellular enzymes were present in the G. oxydans cell-free extract: sorbitol dehydrogenase, and mannitol dehydrogenase. Substrate reduction occurred optimally at a low pH (pH 6), while the optimum for substrate oxidation was situated at alkaline pHs (pH 9.5–10.5). The mannitol dehydrogenase was more thermostable than the sorbitol dehydrogenase. The cell-free extract could be used to produce D-mannitol and D-sorbitol enzymatically from D-fructose. Efficient coenzyme regeneration was accomplished by formate dehydrogenase-mediated oxidation of formate into CO2. 相似文献
16.
A heat shock was applied to Saccharomyces cerevisiae: a change from 18°C to 45°C over 5 min and then maintenance at later temperature for 20 min followed by cooling to 18°C.
Such a treated inoculum, when used in an alcoholic fermentation of Welsch Riesling grape must at 18°C, gave up to 12 g glycerol l−1 This is a new and easy method for high glycerol production in large scale wine production. 相似文献
17.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes. 相似文献
18.
Gluconobacter oxydans is an industrially important bacterium that possesses many uncharacterized oxidoreductases, which might be exploited for novel biotechnological applications. In this study, gene gox1801 was homologously overexpressed in G. oxydans and it was found that the relative expression of gox1801 was 13-fold higher than that in the control strain. Gox1801 was predicted to belong to the 3-hydroxyisobutyrate dehydrogenase-type proteins. The purified enzyme had a native molecular mass of 134 kDa and forms a homotetramer. Analysis of the enzymatic activity revealed that Gox1801 is a succinic semialdehyde reductase that used NADH and NADPH as electron donors. Lower activities were observed with glyoxal, methylglyoxal, and phenylglyoxal. The enzyme was compared to the succinic semialdehyde reductase GsSSAR from Geobacter sulfurreducens and the γ-hydroxybutyrate dehydrogenase YihU from Escherichia coli K-12. The comparison revealed that Gox1801 is the first enzyme from an aerobic bacterium reducing succinic semialdehyde with high catalytic efficiency. As a novel succinic semialdehyde reductase, Gox1801 has the potential to be used in the biotechnological production of γ-hydroxybutyrate. 相似文献
19.
Ae-Young Mo Bora Kwon Seralathan Kamala-Kannan Kui-Jae Lee Byung-Taek Oh Dae-Hyuk Kim Moon-Sik Yang Jin-Hyung Kim Seung-Moon Park 《World journal of microbiology & biotechnology》2010,26(6):1099-1105
Bacteria of the Bacillus species have been reported as an important microorganism in fermented soybean products. In the present study, thirty Bacillus isolates were screened from Meju, a Korean soybean fermentation starter. The comparative analysis of 16S rDNA sequences, 16S-23S internal transcribed spacer
sequences, phenotypic, and biochemical characterizations revealed three phylogenetically distinct groups namely Bacillus atrophaeus,
Bacillus polyfermenticus and Bacillus subtilis. The isolates were assayed for poly-γ-glutamate production and fibrinolytic activity. Among the isolates, B. polyfermenticus exhibited maximum poly-γ-glutamate production and fibrinolytic activity. Moreover, the soybean products fermented by B. polyfermenticus have increased the time taken for coagulation and hemorrhage in mice. The results of the present study clearly indicate the
functional role of B. polyfermenticus in fermented soybean products. 相似文献
20.
A genetic transformation system has been developed for callus cells of Crataegus
aronia using Agrobacterium
tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with
5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different
types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red
colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli
were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this
is the first time to report an Agrobacterium-mediated transformation system in Crataegus
aronia. 相似文献