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1.
Kinetic model for biotransformation of digitoxin in plant cell suspension culture ofDigitalis lanata
Jeong-Woo Choi Young-Kee Kim Hyun-Kyu Park Won Hong Lee Dong-Il Kim 《Biotechnology and Bioprocess Engineering》1999,4(4):281-286
Batch suspension cultures ofDigitalis lanata plant cell were performed to investigate the biotransformation of digitoxin.Digitalis lanata K3OHD plant cells were used to biotransform digitoxin into deacetyllanatoside C. A kinetic model was proposed to describe
cell growth, substrate consumption, depletion of digitoxin, formation and depletion of digoxin and purpureaglycoside A, and
formation of deacetyllanatoside C. The digoxin and purpureaglycoside A are intermediates of deacetyllanatoside C formation
from digitoxin. Interactions between extracellular and intracellular compounds were considered. The proposed model could accurately
predict cell growth, substrate consumption and product synthesis. And it can provide a useful framework for quantitative analysis
of biotransformation in a plant cell culture system. 相似文献
2.
A biotransformation process for the production of digoxin was developed using Digitalis lanata cell suspension cultures. Digitoxin was used as the substrate for biotransformation. Digoxin production was carried out in a variety of vessels, including 1-l exsiccators, 20-l glass reactors and a 300-l air-lift bioreactor. A culture volume of 200 l was established after 28 d and the cells were then cultured semi-continuously in a 300-l bioreactor employing the draw-fill cultivation method. Maximal digoxin production was achieved in an 8% glucose medium with a production optimum after 40-60 h of incubation in the presence of 0.65-0.8 mmol digitoxin per l. Levels of 0.52, 0.53 and 0.60 mmol digoxin per l suspension were achieved in 1-l, 20-l and 300-l vessels, respectively. About 80% of the digoxin produced was found in the bathing medium. 相似文献
3.
Naivy Pérez-Alonso Dirk Wilken André Gerth Annett Jähn Horst-Michael Nitzsche Gerhard Kerns Alina Capote-Perez Elio Jiménez 《Plant Cell, Tissue and Organ Culture》2009,99(2):151-156
Cardiotonic glycosides are extracted mostly from leaves of Digitalis plants. Commercial production of bioactive secondary metabolites by traditional agriculture is an inefficient process and
can be affected by climatic and soil conditions. Strategies, based on in vitro culture methods, have been extensively studied
to improve the production of specific plant derived chemicals. The aim of the present research was to obtain biomass of D. purpurea using the temporary immersion system (TIS) and to determine the content of cardiotonic glycosides (digitoxin, digoxin and
lanatoside C) as secondary metabolites of commercial value for the pharmaceutical industry. Shoots were cultured in 1,000 ml
TIS during 28 days. The effect of four immersion frequencies (once every 2, 4, 6, and 12 h) was studied. Biomass accumulation
was influenced by immersion frequency. The maximum biomass accumulation (values in respect of fresh and dry weight) was obtained
with immersions every 4 h (six immersions per day). HPLC analysis revealed the presence of digoxin and digitoxin for all immersion
frequencies. No lanatoside C was detected in the biomass cultured in TIS. Digoxin concentrations varied depending on the frequencies
tested. In contrast, the digitoxin content showed no dependency on the immersion frequency. Net production of digoxin and
digitoxin per TIS were found to be higher with immersions every 4 h. The best net production of digitoxin and digoxin per
TIS were 167.6 and 119.9 μg, respectively. The development of organ culture based on temporary immersion system can be a reliable
method for the steady production of biomass for cardiotonic glycosides production, which is reported for the first time for
Digitalis genus in this communication. 相似文献
4.
Faramarzi MA Yazdi MT Jahandar H Amini M Monsef-Esfahani HR 《Journal of industrial microbiology & biotechnology》2006,33(9):725-733
The strain of Acremonium strictum PTCC 5282 was applied to investigate the biotransformation of androst-1,4-dien-3,17-dione (I; ADD). Microbial products obtained were purified by preparative TLC and the pure metabolites were characterized on the basis of their spectroscopic features (13C NMR, 1H NMR, FTIR, MS) and physical constants (melting points and optical rotations). The 15α-Hydroxyandrost-1,4-dien-3,17-dione (II), 17β-hydroxyandrost-1,4-dien-3-one (III), androst-4-en-3,17-dione (IV; AD), 15α-hydroxyandrost-4-en-3,17-dione (V), 15α,17β-dihydroxyandrost-1,4-dien-3-one (VI) and testosterone (VII) were produced during this fermentation. Formation of the 15α,17β-dihydroxy derivative of ADD is reported for the first time during steroid biotransformation. The bioconversion reactions observed were 1,2-hydrogenation, 15α-hydroxylation and 17-ketone reduction. From the time course profile of this biotransformation, ketone reduction and 1,2-hydrogenation were observed from the first day of fermentation while 15α-hydroxylation occurred from the third day. Optimum concentration of the substrate, which gave the maximum bioconversion efficiency, was 0.5 mg ml−1 in one batch. The highest yield of the microbial products recorded in this work was achieved within the pH range 6.5–7.3 and at the temperature of 27 °C. 相似文献
5.
D. Hernández-Rodríguez J. E. Sánchez M. G. Nieto F. J. Márquez-Rocha 《World journal of microbiology & biotechnology》2006,22(7):753-760
Summary Endosulfan is an insecticide used on many vegetable crops. In mushroom cultivation, vegetable materials used as a growth substrate
may contain residues of endosulfan that may accumulate in the final mushroom biomass. After preparing the substrate, it is
subjected to pasteurization and/or composting and then inoculated with the desired fungus. The purpose of this research was
to determine the rate and extent of endosulfan reduction from a grass substrate that was either composted or sterilized by
autoclaving. In addition, the rate and extent of removal of endosulfan from substrate colonized with Pleurotus pulmonarius was determined. The degradation of 65 mg/kg endosulfan was analyzed on both, the substrate preparation and the culture of
P.
pulmonarius on the grass Digitaria
decumbens. During composting in presence of Ca(OH)2 for 120 h, the concentrations of α and β endosulfan were reduced by 61.4 and 49.5% respectively, significantly higher compared
with the control (without Ca(OH)2,) in which the reduction was 38.5%. After sterilization the concentration of α and β endosulfan was reduced by 84.8 and 87.5%
respectively. After the colonization of substrate by P. pulmonarius (15 days after spawning) α and β endosulfan were reduced by 96% and at the end of cultivation (35 days after spawning) were
reduced by 99%. When carpophores were analyzed, residues of α and β endosulfan were observed between 0.019–0.084 mg/kg. The
results showed that α and β endosulfan were partially removed during the preparation of substrate and entirely eliminated
during fungal colonization on the substrate. 相似文献
6.
S. Ramachandra Rao Usha Tripathi G.A. Ravishankar 《Biocatalysis and Biotransformation》2013,31(2):137-143
Cell suspension cultures of Capsicum frutescens accumulated digoxin, purpureaglycoside A and other unknown derivatives when digitoxin, a cardiac glycoside, was used as a precursor. The feeding of digitoxin complexed with g -cyclodextrin increased the accumulation of digoxin, purpureaglycoside A and other unknown derivatives. Control cultures (without digitoxin) did not produce any of these metabolites. The growth of cells was affected by both digitoxin as well as digitoxin- g -cyclodextrin. The accumulation of purpureaglycoside A and digoxin reached a maximum of 1241 and 374 w g 100 ml m 1 culture on the 6th and 2nd day, respectively, which was 3.9 and 4.5 fold higher than cultures treated with digitoxin alone (sampled on the 13th day). The other unknown derivatives formed in digitoxin- g -cyclodextrin fed cultures were 15 times higher than digitoxin alone fed C. frutescens cultures. The addition of glucose to digitoxin- g -cyclodextrin treated cultures increased the accumulation of purpureaglycoside A which reached a maximum of 3589 w g 100 ml m 1 culture after 12 h incubation, which was a 2.9 fold increase over cultures treated with digitoxin- g -cyclodextrin alone. 相似文献
7.
Petrovic L Pohle D Münstedt H Rechtenwald T Schlegel KA Rupprecht S 《Journal of biomedical science》2006,13(1):41-46
Summary Non-resorbable thermoplastic polymers have become more important for reconstructive surgery due to their excellent chemical
and physical properties. Polyetheretherketone-β-tricalcium phosphate (βTCP-PEEK) composites were developed as alternative
materials for load-bearing applications. This study presents the effect of polyetheretherketone (PEEK) specimens incorporated
with 5, 10, 20 and 40 wt% β-tricalcium phosphate (βTCP) and processed by injection molding on cultivated osteoblast cells.
Normal human osteoblast (NHOst) cells were seeded onto polymer discs to evaluate cell viability and proliferation after 24,
72 and 120 h of cultivation by employing the WST-1 assay. Standard tissue culture plastic was used as a control. The osteoblast
cells were found to be viable in all PEEK groups, while the cell proliferation was progressively inhibited due to the incorporated
β-tricalcium phosphate. βTCP-PEEK showed concentration independent decrease of cell proliferation compared to the unfilled
PEEK and the control group. In summary, this study confirms the non-toxic nature of pure PEEK, whereas this could not definitely
be verified for βTCP-PEEK as a composite material in chosen concentrations of β-tricalcium phosphate in vitro. 相似文献
8.
Eukaryotic algae were studied to determine their ability to biotransform HgII under aerated and pH controlled conditions. All algae converted HgII into β-HgS and Hg0 to varying degrees. When HgII was administered as HgCl2 to the algae, biotransformation by species of Chlorophyceae (Selenastrum
minutum and Chlorella fusca var. fusca) was initiated with β-HgS synthesis (K
1/2 of hours) and concomitant Hg° evolution occurred in the first hour. Hg° synthesis was impeded by the formation of β-HgS and
this inhibition was released in C. fusca var. fusca when cellular thiols were oxidized by the addition of dimethylfumarate (DMF). The diatom, Navicula pelliculosa (Bacillariophyceae), converted a substantially greater proportion of the applied HgII into Hg0, whereas the thermophilic alga, Galdieria sulphuraria (Cyanidiophyceae), rapidly biotransformed as much as 90% of applied HgII into β-HgS (K
1/2 ≈ 20 min). This thermophile was also able to generate Hg0 even after all exogenously applied HgCl2 had been biotransformed. The results suggest that β-HgS may be the major dietary mercurial for grazers of contaminated eukaryotic
algae. 相似文献
9.
Ye. M. Nogovitsina V. V. Grishko I. B. Ivshina 《Russian Journal of Bioorganic Chemistry》2011,37(5):626-633
Conditions for a directed biocatalytic oxidation of β-sitosterol to pharmacologically valuable stigmast-4-en-3-one using Rhodococcus actinobacteria were determined. It was shown that palmitic acid induced the cholesterol oxidase reaction and allowed for
the decrease in the bioconversion process duration from 7 to 5 days. The maximum level of stigmast-4-ene-3-one formation was
achieved using an additional growth substrate n-hexadecane. With increased concentrations of β-sitosterol (up to 2 g/l) an effective target product formation (80%) was achieved
in the presence of Tween-80 and β-cyclodextrin. R. erythropolis strains were 1.5–2 times more active than R. ruber strains in catalyzing the β-sitosterol biotransformation process. 相似文献
10.
Mark L. Thompson Ray Marriott Adam Dowle Gideon Grogan 《Applied microbiology and biotechnology》2010,85(3):721-730
The biocatalytic generation of high-value chemicals from abundant, cheap and renewable feedstocks is an area of great contemporary
interest. A strain of Rhodococcus erythropolis designated MLT1 was isolated by selective enrichment from the soil surrounding hop plants, using the abundant triene β-myrcene
from hops as a sole carbon source for growth. Resting cells of the organism were challenged with β-myrcene, and the major
product of biotransformation was determined by mass spectrometric analysis to be the monoterpene alcohol geraniol. Controls
demonstrated that the product was biogenic and that an aerobic environment was required. The ability to transform β-myrcene
was shown to be restricted to cells that had been grown on this substrate as sole carbon source. Pre-incubation of cells with
the cytochrome P450 inhibitors metyrapone or 1-aminobenzotriazole reduced geraniol production by 23% and 73% respectively,
but reduction in activity was found not to correlate with the inhibitor concentration. A comparative analysis of insoluble
and soluble cell extracts derived from cells of MLT1 grown on either β-myrcene or glucose revealed at least four proteins
that were clearly overproduced in response to growth on β-myrcene. Mass spectrometric analysis of tryptic digests of three
of these protein bands suggested their identities as an aldehyde dehydrogenase, an acyl-CoA dehydrogenase and a chaperone-like
protein, each of which has a precedented role in hydrocarbon metabolism clusters in Rhodococcus sp. and which may therefore participate in a β-myrcene degradation pathway in this organism. 相似文献
11.
Heinrich Spieler A. Wilhelm Alfermann Ernst Reinhard 《Applied microbiology and biotechnology》1985,23(1):1-4
Summary
Digitalis lanata cells were grown at dif-ferent dissolved-oxygen (DO) levels in 20-1 airlift reactors. A DO level of 30% saturation (using
air for aeration) was found to be optimal for growth and the biotransformation ofβ-methyldigitoxin toβ-methyldigoxin. Product yield was further in-creased by using stirred tank reactors instead of the airlift reactor. 相似文献
12.
Calcium is a known signalling molecule in eukaryotic cells and plays a central role in the regulation of many cellular processes.
In the following study, we report on the effect of external calcium treatments on the biotransformation of ginsenoside Rb1
to ginsenoside Rd by Paecilomyces bainier 229-7. We observed that the intracellular calcium content of P. bainier 229-7 mycelia was increased in response to exposure to high external Ca2+ concentrations. Both ginsenoside Rd biotransformation and β-glucosidase activity were both found to be dependent on the external
calcium concentration. At an optimal Ca2+ concentration of 45 mM, maximal ginsenoside Rd bioconversion rate of 92.44% was observed and maximal β-glucosidase activity
of 0.1778 U was reached in a 72-h biotransformation. The Ca2+ channel blocker Verapamil blocked the trans-membrane influx of calcium and decreased ginsenoside Rd biotransformatiom. In
addition, β-glucosidase activity and ginsenoside Rd content decreased by 36.0 and 29.2% respectively after a 72-h incubation
in the presence of 0.05 mM Calmodulin (CaM) antagonist Perphenazine. These results suggest that both Ca2+ channels and CaM are involved in ginsenoside Rd biotransformation via regulation of β-glucosidase activity. This is the first
report regarding the effects of calcium signal transduction on biotransformation and enzyme activity in fungi. 相似文献
13.
β-Glucosidase and β-galactosidase activity profile tested in different seeds during 24 h germination revealed reasonably high
levels of activity inVigna radiata, Cicer arietinum, andTrigonella foenum-graecum. In all seeds tested, β-galactosidase activity was, in general, higher than that of β-glucosidase.T. foenum-graecum seedlings exhibited maximal total and specific activities for both the enzymes during 72 h germination. Se supplementation
as Na2SeO3 up to 0.75 ppm was found to be beneficial to growth and revealed selective enhancement of β-galactosidase activity by 40%
at 0.5 ppm Se. The activities of both the enzymes drastically decreased at 1.0 ppm level of Se supplementation. On the contrary,
addition of Na2SeO3 in vitro up to 1 ppm to the enzyme extracts did not influence these activities. Hydrolytic rates of β-glucosidase in both
control and Se-supplemented groups were enhanced by 20% with 0.05M glycerol in the medium and 30% at 0.1M glycerol. The rates were marginally higher in Se-supplemented seedlings than the controls, irrespective of added glycerol
in the medium. In contrast, hydrolysis by β-galactosidase showed a trend of decrease in Se-supplemented seedlings compared
to the control, when glycerol was present in the medium. Addition of Se in vitro in the assay medium showed no difference
in the hydrolytic rate by β-galactosidase when compared to control, while the activity of β-glucosidase declined by 50%. Se-grown
seedlings showed an enhancement of transglucosidation rate by 40% in the presence of 0.1M glycerol. The study reveals a differential response to Se among the β-galactosidase and β-glucosidase ofT. foenumgraecum with increase in the levels of β-galactosidase activity. 相似文献
14.
Of three β-galactosidases from Aspergillus oryzae, Kluyveromyces lactis and Bacillus sp., used for the production of low-content galacto- oligosaccharides (GOS) from lactose, the latter produced the highest
yield of trisaccharides and tetrasaccharides. GOS production was enhanced by mixing β-galactosidase glucose oxidase. The low-content
GOS syrups, produced either by β-galactosidase alone or by the mixed enzyme system, were subjected to the fermentation by
Kluyveromyces marxianus, whereby glucose, galactose, lactose and other disaccharides were depleted, resulting in up to 97% and 98% on a dry weight
basis of high-content GOS with the yields of 31% and 32%, respectively.
An erratum to this article can be found at 相似文献
15.
Hua D Ma C Song L Lin S Zhang Z Deng Z Xu P 《Applied microbiology and biotechnology》2007,74(4):783-790
High vanillin productivity was achieved in the batch biotransformation of ferulic acid by Streptomyces sp. strain V-1. Due to the toxicity of vanillin and the product inhibition, fed-batch biotransformation with high concentration
of ferulic acid was unsuccessful. To solve this problem and improve the vanillin yield, a biotransformation strategy using
adsorbent resin was investigated. Several macroporous adsorbent resins were chosen to adsorb vanillin in situ during the bioconversion.
Resin DM11 was found to be the best, which adsorbed the most vanillin and the least ferulic acid. When 8% resin DM11 (wet
w/v) was added to the biotransformation system, 45 g l−1 ferulic acid could be added continually and 19.2 g l−1 vanillin was obtained within 55 h, which was the highest vanillin yield by bioconversion until now. This yield was remarkable
for exceeding the crystallization concentration of vanillin and therefore had far-reaching consequence in its downstream processing. 相似文献
16.
Michikatsu Sato Machiko Watanabe Hiroto Nagano Yoshiaki Yagi 《Biotechnology letters》1994,16(7):703-708
A simple and specific recovery method for α-cyclodextrin (α-CD) was developed by employing co-digestion of CD reaction mixtures
with CGTase fromBacillus ohbensis and α-glucosidase. The combination of CGTase fromB. ohbensis and α-glucosidase, such as α-amylase, β-amylase, or glucoamylase was examined for the selective degradation of β-and γ-CD
in the CD reaction mixture formed by CGTase fromB. macerans. The co-digestion of the CD mixture with Taka-amylase and the CGTase resulted in α-CD and maltodextrins, the combination
with β-amylase resulted in α-CD and maltose, and that with glucoamylase resulted in α-CD and glucose. The conditions of selective
degradation of β- and γ-CD by co-digestion with the CGTase and glucoamylase were optimized as follows: the incubation pH,
5.5; incubation temperature, 50°C; CGTase concentration, 15 u/g of substrate; glucoamylase, 10 u/g of substrate; substrate
concentration, 10% (w/v); the incubation time was fixed for 18 hr from the stand point of operation convenience.
Most part of the content was presented in poster session at the 7th International Cyclodextrin Symposium, Tokyo, April 1994. 相似文献
17.
Ong RM Goh KM Mahadi NM Hassan O Rahman RN Illias RM 《Journal of industrial microbiology & biotechnology》2008,35(12):1705-1714
The cyclodextrin glucanotransferase (CGTase, EC 2.4.1.19) gene from Bacillus sp. G1 was successfully isolated and cloned into Escherichia coli. Analysis of the nucleotide sequence revealed the presence of an open reading frame of 2,109 bp and encoded a 674 amino acid
protein. Purified CGTase exhibited a molecular weight of 75 kDa and had optimum activity at pH 6 and 60°C. Heterologous recombinant
protein expression in E. coli is commonly problematic causing intracellular localization and formation of inactive inclusion bodies. This paper shows that
the majority of CGTase was secreted into the medium due to the signal peptide of Bacillus sp. G1 that also works well in E. coli, leading to easier purification steps. When reacted with starch, CGTase G1 produced 90% β-cyclodextrin (CD) and 10% γ-CD.
This enzyme also preferred the economical tapioca starch as a substrate, based on kinetics studies. Therefore, CGTase G1 could
potentially serve as an industrial enzyme for the production of β-CD. 相似文献
18.
Kaya M Ito J Kotaka A Matsumura K Bando H Sahara H Ogino C Shibasaki S Kuroda K Ueda M Kondo A Hata Y 《Applied microbiology and biotechnology》2008,79(1):51-60
For efficient production of isoflavone aglycones from soybean isoflavones, we isolated three novel types of β-glucosidase
(BGL1, BGL3, and BGL5) from the filamentous fungi Aspergillus oryzae. Three enzymes were independently displayed on the cell surface of a yeast Saccharomyces cerevisiae as a fusion protein with α-agglutinin. Three β-glucosidase-displaying yeast strains hydrolyzed isoflavone glycosides efficiently
but exhibited different substrate specificities. Among these β-glucosidases, BGL1 exhibited the highest activity and also
broad substrate specificity to isoflavone glycosides. Although glucose released from isoflavone glycosides are generally known
to inhibit β-glucosidase, the residual ratio of isoflavone glycosides in the reaction mixture with BGL1-displaying yeast strain
(Sc-BGL1) reached approximately 6.2%, and the glucose concentration in the reaction mixture was maintained at lower level.
This result indicated that Sc-BGL1 assimilated the glucose before they inhibited the hydrolysis reaction, and efficient production
of isoflavone aglycones was achieved by engineered yeast cells displaying β-glucosidase. 相似文献
19.
Capel CS de Souza AC de Carvalho TC de Sousa JP Ambrósio SR Martins CH Cunha WR Galán RH Furtado NA 《Journal of industrial microbiology & biotechnology》2011,38(9):1493-1498
The goal of this study is to produce oleanolic acid derivatives by biotransformation process using Mucor rouxii and evaluate their antimicrobial activity against oral pathogens. The microbial transformation was carried out in shake flasks
at 30°C for 216 h with shaking at 120 rpm. Three new derivatives, 7β-hydroxy-3-oxo-olean-12-en-28-oic acid, 7β,21β-dihydroxy-3-oxo-olean-12-en-28-oic
acid, and 3β,7β,21β-trihydroxyolean-12-en-28-oic acid, and one know compound, 21β-hydroxy-3-oxo-olean-12-en-28-oic acid, were
isolated, and the structures were elucidated on the basis of spectroscopic analyses. The antimicrobial activity of the substrate
and its transformed products was evaluated against five oral pathogens. Among these compounds, the derivative 21β-hydroxy-3-oxo-olean-12-en-28-oic
acid displayed the strongest activity against Porphyromonas gingivalis, which is a primary etiological agent of periodontal disease. In an attempt to improve the antimicrobial activity of the
derivative 21β-hydroxy-3-oxo-olean-12-en-28-oic acid, its sodium salt was prepared, and the minimum inhibitory concentration
against P. gingivalis was reduced by one-half. The biotransformation process using M. rouxii has potential to be applied to the production of oleanolic acid derivatives. Research and antimicrobial activity evaluation
of new oleanolic acid derivatives may provide an important contribution to the discovery of new adjunct agents for treatment
of dental diseases such as dental caries, gingivitis, and periodontitis. 相似文献
20.
Teng D Fan Y Yang YL Tian ZG Luo J Wang JH 《Applied microbiology and biotechnology》2007,74(5):1074-1083
β-1,3-1,4-glucanase (EC3.2.1.73) as an important industrial enzyme has been widely used in the brewing and animal feed additive
industry. To improve expression efficiency of recombinant β-1,3-1,4-glucanase from Bacillus licheniformis EGW039(CGMCC 0635) in methylotrophic yeast Pichia pastoris GS115, the DNA sequence encoding β-1,3-1,4-glucanase was designed and synthesized based on the codon bias of P. pastoris, the codons encoding 96 amino acids were optimized, in which a total of 102 nucleotides were changed, the G+C ratio was simultaneously
increased from 43.6 to 45.5%. At shaking flask level, β-1,3-1,4-glucanase activity is 67.9 and 52.3 U ml−1 with barley β-glucan and lichenan as substrate, respectively. At laboratory fermentor level, the secreted protein concentration
is approximately 250 mg l−1. The β-1,3-1,4-glucanase activity is 333.7 and 256.7 U ml−1 with barley β-glucan and lichenan as substrate, respectively; however, no activity of this enzyme on cellulose is observed.
Compared to the nonoptimized control, expression level of the optimized β-1,3-1,4-glucanase based on preferred codons in P. pastoris shown a 10-fold higher level. The codon-optimized enzyme was approximately 53.8% of the total secreted protein. The optimal
acidity and temperature of this recombinant enzyme were pH 6.0 and 45°C, respectively. 相似文献