共查询到20条相似文献,搜索用时 31 毫秒
1.
O.V. Krasilnikov M.-F.P. Capistrano L.N. Yuldasheva R.A. Nogueira 《The Journal of membrane biology》1997,156(2):157-172
Replacement of an amino acid residue at position 130 -Gly by Cys- in the primary structure of Staphylococcus aureus alpha-toxin
decreases the single-channel conductance induced by the toxin in planar lipid bilayers. Concomitantly, the pH value at which
the channel becomes unable to discriminate between Cl− and K+ ions is also decreased. By contrast, the pH dependence of the efficiency of the mutant toxin to form ion channels in lipid
bilayers was unchanged (maximum efficiency at pH 5.5–6.0). The asymmetry and nonlinearity of the current-voltage characteristics
of the channel were increased by the point mutation but the diameter of the water pore induced by the mutant toxin, evaluated
in lipid bilayers and in erythrocyte membranes, was found to be indistinguishable from that formed by wild-type toxin and
equal to 2.4–2.6 nm.
Alterations at the ``trans mouth' were found to be responsible for all observed changes of the channel properties. This mouth is situated close to
the surface of the second leaflet of a bilayer lipid membrane. The data obtained allows us to propose that the region around
residue 130 in fact determines the main features of the ST-channel and takes part in the formation of the trans entrance of the channel.
Received: 8 September 1995/Revised: 20 November 1996 相似文献
2.
F. A. Hammerschlag P. J. Bottino R. N. Stewart 《Plant Cell, Tissue and Organ Culture》1981,1(1):247-254
Experiments were designed to determine whetherXanthomonas campestris pv.pelargonii produces a toxin which induces symptoms of bacterial blight in geranium, and is active at the cellular level. Culture filtrates
ofX. c. pv.pelargonii were prepared by ethyl acetate extraction and ultrafiltration of the aqueous fraction. Culture filtrates adjusted to several
pH values induced maximum disease ratings on geranium seedlings in the pH range 7–10. Geranium callus growth was significantly
reduced by the filtrate in the same pH range. An active fraction could also be isolated from diseased tissue. A thin-layer
chromatography-callus bioassay system detected toxin activity in the culture filtrate and in extracts of geranium stems inoculated
withX. c. pv.pelargonii. Callus growth inhibition was located at Rf = 0.2–0.3 for both sources of toxin. These results suggest thatX. c. pv.pelargonii produces a toxin which causes disease symptoms, is present in diseased tissues, and inhibits callus growth. This opens the
possibility of developing resistance to this pathogen by selecting cells insensitive to the toxin and regenerating plants
from these cells. 相似文献
3.
A. De Smul J. Dries L. Goethals H. Grootaerd W. Verstraete 《Applied microbiology and biotechnology》1997,48(3):297-303
In a mesophilic (30–35 °C), sulphidogenic, ethanol-fed expanded-granular-sludge-blanket reactor, sulphate, at loading rates
of up to 10.0–12.0 g Sl−1␣day−1, was removed with an average efficiency of more than 80%. The pH was between 7.7 and 8.3 and the maximal total dissolved
sulphide concentration was up to 20 mM S (650 mg S/l). The alkaline pH was maintained by either a pH-control unit with sodium
hydroxide or by stripping part of the sulphide and CO2 from the recycle with nitrogen gas. The superficial upstream liquid velocity (v
up) was 3.0–4.5 m/h. The ratio of ethanol to sulphur was near stoichiometry. At alkaline pH, the activity of the acetotrophic
sulphate-reducing bacteria, growing on acetate, was strongly enhanced, whereas at pH below 7.7 the acetotrophic sulphate-reducing
bacteria were inhibited by aqueous H2S. With regard to the removal efficiency and operational stability, external stripping with N2 and pH control were equally successful.
Received: 2 December 1996 / Received revision: 13 March 1997 / Accepted: 15 March 1997 相似文献
4.
The effect of pH on the photosynthetic properties of photosystem I (PSI) particles isolated from spinach chloroplasts were
studied using various spectroscopic and activity measurements. The results indicated that the PSI light energy absorption
was not affected by changing pH of suspending media. The low-temperature fluorescence yield of the dominating long-wavelength
emission band at 734 nm was decreased with increasing pH, whereas it did not exhibit changes in the major peak position at
pHs studied except for pH 12, where the major peak in low-temperature chlorophyll (Chl) fluorescence emission spectra was
shifted toward the blue light by 5 nm. Pronounced changes were found in PSI photochemical activities. Mild alkalinity (pH
8–10) in suspending media stimulated the rate of oxygen uptake with a maximum activity of oxygen consumption at about pH 9,
while the other pHs exhibited an inhibition as compared to the control at pH 7.8. The rate of P700 photooxidation increased
with the increasing pH, and the optimum for the reaction activity was in the region of pH 9–11. Circular dichroism spectra
revealed that a progressive increase occurred in the conformation of the α-helices as pH value decreased from pH 7.8 to 3.0
or increased from pH 7.8 to 12.0. The results demonstrated that the Chl states in PSI particles were highly stable, while
the photochemical activities and protein secondary structures were very sensitive to the pH stimuli of external medium. 相似文献
5.
Jianshe Wang Yingguo Bai Peilong Yang Pengjun Shi Huiying Luo Kun Meng Huoqing Huang Jun Yin Bin Yao 《World journal of microbiology & biotechnology》2010,26(5):917-924
A xylanase gene, xynE2, was cloned from thermoalkaline Anoxybacillus sp. E2 and was expressed in Escherichia coli BL21 (DE3). The gene consisted of 987 bp and encoded a 328-residue xylanase with a calculated molecular weight of 38.8 kDa.
On the basis of amino acid sequence similarities, this enzyme was assigned as a member of glycoside hydrolase family 10. Purified
recombinant XynE2 showed maximal activity at pH 7.8 and 65°C, and was thermostable at 60°C. The enzyme was highly active and
stable over a broad pH range, showing more than 90% of maximal activity at pH 6.6–pH 8.6 and retaining more than 80% of activity
at pH 4.6–pH 12.0, 37°C for 1 h, respectively. These favorable properties make XynE2 a good candidate in the pulp and paper
industries. This is the first report on gene cloning, expression and characterization of a xylanase from the genus Anoxybacillus. 相似文献
6.
Microcystis aeruginosa isolated in 2005 from the shallow eutrophic Lake Chao (Anhui, China) was investigated in terms of growth parameters and microcystin
production under varying nutrient concentrations (P, N) and pH values (abiotic factors) as well as under the influence of
spent medium of the non-toxic cyanobacterium Synechocystis sp. (biotic factors). Stimulating effects on growth were observed at the alkaline pH value (10.5), whereas toxin production
was significantly increased under phosphate-P limitation (0.6 mg L−1 medium). Within a broad range of nitrate–N concentrations (41.2–247.2 mg L−1 medium), no significant influence on cell growth and microcystin production was observed; however, N-starvation resulted
in a typical decrease of growth and toxicity. In addition, cryopreservation of M. aeruginosa evidenced the decrease of toxin production by time-dependent exposure with the cryoprotectant dimethyl sulfoxide under thawing
conditions without affecting the growth of the cyanobacterial cells. 相似文献
7.
This study investigated the effects of surfactant additives and medium pH on mycelial morphology and exopolysaccharide (EPS)
production in liquid culture of a valuable medicinal fungus Cordyceps sinensis Cs-HK1. In the medium containing 20 g l−1 glucose and 6 g l−1 peptone as the sole nitrogen source, the Cs-HK1 fungal mycelia formed smooth and spherical pellets about 1.8-mm mean diameter.
The mycelial pellets became less uniform at pH (4.0–5.0) lower than the optimum (pH 6.0) or turned to filamentous form at
higher pH (8–9). Surfactants added to the medium inhibited pellet formation, resulting in smaller and looser pellets. Tween
80 exhibited a remarkable promoting effect on EPS production, increasing the EPS yield more than twofold at 1.5% (w/v), which
was most probably attributed to the stimulation of EPS biosynthesis and release from the fungal cells by Tween 80. 相似文献
8.
Junpei Zhou Pengjun Shi Rui Zhang Huoqing Huang Kun Meng Peilong Yang Bin Yao 《Journal of industrial microbiology & biotechnology》2011,38(4):523-530
A pH-stable and protease-resistant xylanase (XynB119) was identified from Streptomyces sp. TN119, a strain isolated from the gut luminal contents of longhorned beetle (Batocera horsfieldi) larvae. Using the GC TAIL-PCR method, the 1,026-bp coding gene (xynB119) with 67.3% GC content was successfully cloned and expressed in Escherichia coli. It encodes a 341-residue polypeptide with a calculated molecular mass of 35.9 kDa, including a putative 41-residue signal
peptide, a catalytic domain of glycosyl hydrolase (GH) family 11, a short Gly/Pro-rich linker, and a family 2 cellulose-binding
domain (CBM 2). The deduced amino acid sequence is most similar to (61.9% identity) an endo-1,4-β-xylanase from Streptomyces thermoviolaceus OPC-520. Purified recombinant XynB119 exhibited peak activity at 50°C and pH 7.0, remained stable over a broad pH range (retaining >70%
activity after incubation at pH 1.0–11.0 for 1 h at 37°C without substrate), had strong protease resistance (retaining >90%
activity after proteolytic treatment at 37°C for 1 h) and SDS resistance (at 100 mM). These properties make XynB119 promising
for application in the feed industry and valuable for basic research. Compared to r-XynB119, the r-XynB119 derivative without
CBM 2 and linker region (r-XynB119d) exhibited a decreased pH stability of >25% at extreme pHs (pH 1.0–3.0 and pH 11.0–12.0). 相似文献
9.
A new xylanase from thermoacidophilic Alicyclobacillus sp. A4 with broad-range pH activity and pH stability 总被引:1,自引:0,他引:1
Yingguo Bai Jianshe Wang Zhifang Zhang Peilong Yang Pengjun Shi Huiying Luo Kun Meng Huoqing Huang Bin Yao 《Journal of industrial microbiology & biotechnology》2010,37(2):187-194
We have identified a highly pH-adaptable and stable xylanase (XynA4) from the thermoacidophilic Alicyclobacillus sp. A4, a strain that was isolated from a hot spring in Yunnan Province, China. The gene (xynA4) that encodes this xylanase was cloned, sequenced, and expressed in Escherichia coli. It encodes a 338-residue polypeptide with a calculated molecular mass of 42.5 kDa. The deduced amino acid sequence is most
similar to (53% identity) an endo-1,4-β-xylanase from Geobacillus stearothermophilus that belongs to family 10 of the glycoside hydrolases. Purified recombinant XynA4 exhibited maximum activity at 55°C and
pH 7.0, had broad pH adaptability (>40% activity at pH 3.8–9.4) and stability (retaining >80% activity after incubation at
pH 2.6–12.0 for 1 h at 37°C), and was highly thermostable (retaining >90% activity after incubation at 60°C for 1 h at pH
7.0). These properties make XynA4 promising for application in the paper industry. This is the first report that describes
cloning and expression of a xylanase gene from the genus Alicyclobacillus. 相似文献
10.
Maria L. Villalonga Reynaldo Villalonga Loredana Mariniello Leissy Gómez Prospero Di Pierro Raffaele Porta 《World journal of microbiology & biotechnology》2006,22(6):595-602
Summary Dextran (MW=7.2×104), carboxymethylcellulose (MW=2.5×104, substitution degree=0.7) and Ficoll (MW=6.9×104) were derivatized with 1,4-diaminobutane and covalently attached to bovine pancreatic trypsin through a transglutaminase-catalysed
reaction. The conjugates contained an average of 0.7–1.8 mol of polymers per mol of protein, and retained about 61–82% of
the original esterolytic activity of trypsin. The optimum pH for trypsin was shifted to alkaline values after enzymatic glycosidation.
The thermostability of the polymer–enzyme complexes was increased in about 13.7–50.0 °C over 10 min incubation. The prepared
conjugates were also more stable against thermal incubation at different temperatures ranging from 50 °C to 60 °C. In comparison
with native trypsin, the enzyme-polymer complexes were about 22- to 48-fold more resistant to autolytic degradation at pH
9.0. Transglutaminase-catalysed glycosidation also protected trypsin against denaturation in surfactant media, with 9- to
68–fold increased half-life times in the presence of 0.3% (w/v) sodium dodecylsulfate. 相似文献
11.
Shainn-Wei Wang William J. McCarthy 《In vitro cellular & developmental biology. Animal》1997,33(4):315-323
Summary A sensitive lactate dehydrogenase (LDH) assay was modified to determine the cytolytic activity of Bacillus thuringiensis CryIC and CryIAc delta endotoxins to viable collagenase-dissociated midgut epithelial cells (MEC) from larvae of Spodoptera frugiperda and Spodoptera exigua. The MEC preparations from these Spodoptera sp. consisted predominantly of columnar cells (65–75%) and goblet cells (25–35%). Time course microscopy experiments indicated
that only the columnar cells became swollen during CryIC toxin incubation. Also, comparative cytotoxicity studies were run
with cell lines of nonmidgut origin established from S. frugiperda (SF21AE) and S. exigua (SEUCR1A). Optimum conditions for the cytotoxicity assay were similar for MEC and cell lines of both species, and were met
in an assay in which 0.1-ml cell concentrations (8.5±0.5×104 cells) were incubated with toxin dilutions (0.01–20 μg) for 1 h at 24° C at a final pH of 7.8.
The Spodoptera sp. MEC were twofold more sensitive to CryIC (68% lysis) than CryIAc (32% lysis) at optimum toxin levels (2.5–5 μg). Also,
the SEUCR1A cells were more sensitive (2.3-fold) to CryIC (70% lysis) than CryIAc (30% lysis) at optimum toxin levels of 5–10
μg. The SF21AE cells, however, were twofold less sensitive to CryIC (30% lysis) than SEUCR1A cells and response to CryIAc
and CryIC was similar.
Immunoblot analysis of either Spodoptera sp. MEC or brush border membrane vesicles (BBMV) identified seven CryIC binding proteins with molecular mass of 137, 120,
115, 68, 65, 63, and 45 kDa. Occasionally, a 148-kDa protein band was observed. The CryIAc toxin bound to two proteins on
MEC and BBMV with molecular mass of 137 and 120 kDa. 相似文献
12.
We have fused the epidermal growth factor (EGF) to the amino terminus of Pseudomonas exotoxin A (PE) to create a cytotoxic agent, designated EGF-PE, which preferentially kills EGF-receptor-bearing cells. In
this study, we analyzed the effect of the Ia domain, the binding domain, of PE on the cytotoxicity of EGF-PE towards EGF-receptor-bearing
cells and tried to develop a more potent EGF-receptor-targeting toxin. EGF-PE molecules with sequential deletions at the amino
terminus of PE were constructed and expressed in E. coli strain BL21(DE3). The cytotoxicity of these chimeric toxins was then examined. Our results show that the amino-terminal and
carboxy-terminal regions of the Ia domain of PE are important for the cytotoxicity of a PE-based targeting toxin. To design
a more potent PE-based EGF-receptor-targeting toxin, a chimeric toxin, named EGF-PE(Δ34–220), which had most of the Ia domain
deleted but retained amino acid residues 1–33 and 221–252 of this domain, was constructed. EGF-PE(Δ34–220) has EGF-receptor-binding
activity but does not show PE-receptor-binding activity and is mildly cytotoxic to EGF-receptor-deficient NR6 cells. As expected,
EGF-PE(Δ34–220) is a more potent cytotoxic agent towards EGF-receptor-bearing cells than EGF-PE(Δ1–252), where the entire
Ia domain of PE was deleted. In addition, EGF-PE(Δ34–220) was shown to be extremely cytotoxic to EGF-receptor-bearing cancer
cells, such as A431, CE81T/VGH, and KB-3-1 cells. We also found that EGF-PE(Δ34–220) was highly expressed in BL21(DE3) and
could be easily purified by urea extraction. Thus, EGF-PE(Δ34–220) can be a useful cytotoxic agent towards EGF-receptor-bearing
cells.
Received : 20 May 1994 / Received last revision : 9 September 1994 / Accepted : 28 September 1994 相似文献
13.
A moderately halophilic strain LY9 with high amylolytic activity was isolated from soil sample obtained from Yuncheng, China.
Biochemical and physiological characterization along with 16S rRNA sequence analysis placed the isolate in the genus Halobacillus. Amylase production started from the post-exponential phase of bacterial growth and reached a maximum level during the early-stationary
phase. The isolate LY9 was found to secrete the amylase, the production of which depended on the salinity of the growth medium.
Maximum amylase production was observed in the presence of 10% KCl or 10% NaCl. Maltose was the main product of soluble starch
hydrolysis, indicating a β-amylase activity. The enzyme showed optimal activity at 60°C, pH 8.0, and 10–12.5% of NaCl. It
was highly active over broad temperature (50–70°C), NaCl concentration (5.0–20.0%), and pH (4.0–12.0) ranges, indicating its
thermoactive and alkali-stable nature. However, activity dropped off dramatically at low NaCl concentrations, showing the
amylase was halophilic. Ca2+ was found to stimulate the β-amylase activity, whereas ethylenediaminetetraacetic acid (EDTA), phenylarsine oxide (PAO),
and diethyl pyrocarbonate (DEPC) strongly inhibited the enzyme, indicating it probably was a metalloenzyme with cysteine and
histidine residues located in its active site. Moreover, the enzyme exhibited remarkable stability towards sodium dodecyl
sulfate
(SDS) and Triton X-100. This is the first report of β-amylase production from moderate halophiles. The present study indicates
that the extracellular β-amylase of Halobacillus sp. LY9 may have considerable potential for industrial application owing to its properties. 相似文献
14.
Luo H Wang K Huang H Shi P Yang P Yao B 《Journal of industrial microbiology & biotechnology》2012,39(4):547-555
In this article, we firstly report a highly alkali-tolerant fungal β-mannanase from Humicola
insolens Y1. The full-length cDNA of the β-mannanase, designated as man5A, has an open reading frame of 1,233 bp that encodes a 411-amino acid polypeptide (Man5A) with a calculated molecular mass
of 42.3 kDa. The deduced sequence of Man5A comprises a putative 20-residue signal peptide and a catalytic domain belonging
to glycoside hydrolase family 5, and displays 61–85% identities with hypothetical proteins and 32–39% with experimentally
verified fungal β-mannanases. Purified recombinant Man5A produced by Pichia pastoris has a specific activity of 1,122 U mg−1 and exhibits optimal activity at pH 5.5 and 70°C. Distinct from other reported fungal β-mannanases, Man5A is highly alkali
tolerant, exhibiting 45 and 36% of the maximal activity at pH 8.0 and 9.0, respectively, and more than 10% activity even at
pH 10.0. Moreover, Man5A has excellent pH stability at pH 5.0–12.0 and is highly thermostable at 50°C. The higher frequency
of alkaline amino acids (Arg and Lys), greater pKa values of the catalytic residues, and more positively charged residues on the surface of Man5A might be the causes. Man5A
has strong resistance to various neutral and alkaline proteases, retaining more than 97% of the activity after proteolytic
treatment for 1 h. The superior characteristics of Man5A make it more advantageous for the application in the kraft pulp industry. 相似文献
15.
Andreas Janshoff Claudia Steinem Manfred Sieber A. el Bayâ Marcus Alexander Schmidt H.-J. Galla 《European biophysics journal : EBJ》1997,26(3):261-270
The binding of cholera toxin, tetanus toxin and pertussis toxin to ganglioside containing solid supported membranes has been
investigated by quartz crystal microbalance measurements. The bilayers were prepared by fusion of phospholipid-vesicles on
a hydrophobic monolayer of octanethiol chemisorbed on one gold electrode placed on the 5 MHz AT-cut quartz crystal. The ability
of the gangliosides GM1, GM3, GD1a, GD1b, GT1b and asialo-GM1 to act as suitable receptors for the different toxins was tested by measuring the changes of quartz resonance frequencies.
To obtain the binding constants of each ligand-receptor-couple Langmuir-isotherms were successfully fitted to the experimental
adsorption isotherms. Cholera toxin shows a high affinity for GM1 (Ka = 1.8 ⋅ 108M–1), a lower one for asialo-GM1 (Ka = 1.0 ⋅ 107 M–1) and no affinity for GM3. The C-fragment of tetanus toxin binds to ganglioside GD1a, GD1b and GT1b containing membranes with similar affinity (Ka∼106 M–1), while no binding was observed with GM3. Pertussis toxin binds to membranes containing the ganglioside GD1a with a binding constant of Ka = 1.6 ⋅ 106 M–1, but only if large amounts (40 mol%) of GD1a are present. The maximum frequency shift caused by the protein adsorption depends strongly on the molecular structure of
the receptor. This is clearly demonstrated by an observed maximum frequency decrease of 99 Hz for the adsorption of the C-fragment
of tetanus toxin to GD1b. In contrast to this large frequency decrease, which was unexpectedly high with respect to Sauerbrey's equation, implying
pure mass loading, a maximum shift of only 28 Hz was detected after adsorption of the C-fragment of tetanus toxin to GD1a.
Received: 14 January 1997 / Accepted: 15 April 1997 相似文献
16.
R. P. Tiwari T. C. Bhalla S. S. Saini G. Singh D. V. Vadehra 《Journal of biosciences》1986,10(1):145-151
The inhibitory effects of aflatoxin B1 were found to be related to the gram character in procaryotes, used in this study. Ethylene diamine tetra chloroacetic acid
(0.05% w/v) or Tween-80 (0.05 % v/v) addition accentuated the aflatoxin B1 growth inhibition inSalmonella typhi andEscherichia coli at different pH values. The inhibition of lipase production was only 5–20 % inPseudomonas fluorescence ca. 25–48% inStaphylococcus aureus andBacillus cereus at different aflatoxin B1 concentrations (4–16μg/ml).However, inhibition of α-amylase induction was complete in1Bacillus megaterium whereas the inhibition was partial inPseudomonas fluorescence (27–40%) at 32μg aflatoxin B1 concentration. An increase in leakage of cell contents and decreased inulin uptake were observed in toxin incubated sheep
red blood cell suspension (1 %) with increased aflatoxin B1 concentration 相似文献
17.
Mustafa Kh. Dabbous Ola Hammouda Burcharda Brinkley 《Molecular and cellular biochemistry》1981,34(2):87-93
Summary Limited proteolysis with pepsin solubilized 25% of the insoluble gingival matrix as mainly soluble collagenous material. Fractional
salt precipication at neutral pH resulted in the separation of types III and I at 1.8 and 2.6 M NaCl, respectively. In addition,
a collagenous fraction accounting for 2% of the solubilized collagen and precipitating at 4.5 M NaCl was shown to be identical
with type V collagen. Isolation and partial characterization of the constituent-α-chains of the 4.5 M PPT by gel filtration,
ion exchange and hydroxylapatite chromatography as well as disc electrophoresis showed that gingival type V collagen contains
αA and αB chains in a ratio αB/αA of 1.73–1.8. Electron microscopic examination of ATP-precipitates showed that this collagen
type gave only one kind of SLS aggregates with asymmetric band pattern characteristically different from that of type I collagen.
The data provide evidence that gingival AB collagen is a heteropolymer in which the αA and αB chains are assembled in the
same macromolecule in a 1∶2 ratio. 相似文献
18.
A halophilic isolate Thalassobacillus sp. LY18 producing extracellular amylase was isolated from the saline soil of Yuncheng Salt Lake, China. Production of the enzyme was synchronized with bacterial growth and reached a maximum level during the early stationary phase. The amylase was purified to homogeneity with a molecular mass of 31 kDa. Major products of soluble starch hydrolysis were maltose and maltotriose, indicating an α-amylase activity. Optimal enzyme activity was found to be at 70°C, pH 9.0, and 10 % NaCl. The α-amylase was highly stable over broad temperature (30–90°C), pH (6.0–12.0), and NaCl concentration (0–20 %) ranges, showing excellent thermostable, alkalistable, and halotolerant nature. The enzyme was stimulated by Ca2+, but greatly inhibited by EDTA, indicating it was a metalloenzyme. Complete inhibition by diethyl pyrocarbonate and β-mercaptoethanol revealed that histidine residue and disulfide bond were essential for enzyme catalysis. The surfactants tested had no significant effects on the amylase activity. Furthermore, it showed high activity and stability in the presence of water-insoluble organic solvents with log P ow ≥ 2.13. 相似文献
19.
Optimum conditions for action of the killer toxin K1 on sensitive strainS. cerevisiae S6 were established. Maximum killing was reached in a very narrow pH range of 4.5–4.6. Maximum susceptibility to toxin was
displayed by highly energized fresh cells from the early exponential phase in the presence of an external energy source (at
least 200 mmol/L glucose). Further, maintenance of maximum membrane potential was necessary for killer action, as documented
by decreasing toxin activity in the presence of increasing concentrations of KCl. The killing was strongly stimulated in the
presence of millimolar concentrations of Ca2+ and Mg2+. 相似文献
20.
G. P. Kononenko A. A. Burkin E. V. Zotova N. A. Soboleva 《Applied Biochemistry and Microbiology》2000,36(2):177-180
Ochratoxin A was quantitatively monitored in grain extracts by indirect solid-phase enzyme immunoassay with the use of an
immobilized conjugate of the toxin with gelatin and polyclonal rabbit antibodies raised against the ochratoxin A-BSA conjugate.
This monitoring found that 1.7 to 18.5% of the samples were contaminated with the toxin at a concentration of 25.9–291.7 μg/kg.
An analysis of forage grain found ochratoxin A at concentrations of 440-3250 μg/kg. 相似文献