共查询到20条相似文献,搜索用时 31 毫秒
1.
Ten species of Aspergillus isolated from soil samples collected from different locations in the Indian Himalayan region have been studied for their
growth requirements and tricalcium phosphate solubilization at different temperatures. The Aspergillus species could grow at low temperature and tolerated a wide range of pH. Phosphate solubilization by various Aspergillus species ranged between 374 μg/ml (A. candidus) to 1394 μg/ml (A. niger) at 28°C, 33 μg/ml (A. fumigatus) to 2354 μg/ml (A. niger) at 21°C, 93 μg/ml (A. fumigatus) to 1452 μg/ml (A. niger) at 14°C, and 21 μg/ml (A. wentii) to 83 μg/ml (A. niger) at 9°C. At 21 and 28°C, phosphate solubilization showed a decrease within 4 weeks of incubation, whereas at 9°C and 14°C,
it continued further up to 6 weeks of incubation. In general, phosphate solubilization by different Aspergillus species was recorded at a maximum of 28°C or 21°C; biomass production was favored at 21°C or 14°C. Conversely, A. nidulans and A. sydowii exhibited maximum phosphate solubilization at 14°C and produced maximum biomass at 21°C. Data suggest that suboptimal conditions
(higher or lower temperature) for fungal growth and biomass production were optimal for the production of metabolites involved
in phosphate solubilization. Significant negative correlations were obtained between pH and phosphate solubilization for eight
species at 28°C, for seven at 21°C, and for nine at 14°C. Extracellular phosphatase activity was exhibited only in case of
A. niger, whreas intracellular phosphatase activity was detected in all species, the maximum being in A. niger. Statistically significant positive or negative correlations were obtained between phosphate solubilization and other parameters
in most cases at different temperatures. 相似文献
2.
Application of sodium-dikegulac reduced plant height with associated increase in branch and leaf number and root biomass inC. roseus (L.) G. DON. Chlorophyll content reduced significantly after first month of 100 and 250 μg/ml DK application. However, such
reduction was replaced by significant rise after forth month in 250 μg/ml DK application and fifth month in 100 μg/ml DK application
followed by appreciable decline only in 250 μg/ml DK treatment but 100 μg/ml DK maintained higher level till harvest. Total
sugar content was significantly high during forth and fifth month stage of growth after DK application. Amino acid content
was higher during third to fifth month in 100 μg/ml DK treatment and during third to forth month in 250 μg/ml DK treatment.
Tryptophan, on the other hand showed higher content at the fifth month stage of growth after application of DK in both the
concentrations. Leaf and root dry weight as well as total alkaloid content were highest in 100 μg/ml DK application. DK, therefore,
appears to be a potential chemical for increasing biomass and alkaloid content inC. roseus. 相似文献
3.
Pseudomonas sp. NBRI 4014 is a potent phosphorus solubilizer (284 μg/ml). It also produced significant levels of siderophore (143.87
μg/ml) and IAA (5.6 μg/ml). Siderotyping indicated it was P. aeruginosa siderovar 1. Cadmium (180 μM), nickel (420 μM), and chromium (370 μM) resistant mutants were developed and characterized
for their PGPR properties. Mutants were stable under non-selective pressure. In cases of nickel and cadmium, there were reductions
of the siderophore levels. However, they were able to promote root and shoot elongation in soybeans (Glycine max PK 564) at a significant level (p < 0.05) in the presence of metals unfamiliar to the wild type. The persistence and stability of mutants were evident in rhizospheric
soil, thus their exploitation for polluted/contaminated sites was supported.
Received: 27 December 2001 / Accepted: 28 January 2002 相似文献
4.
The extracellular metalloprotease (SMP 6.1) produced by a soil isolate of Serratia marcescens NRRL B-23112 was purified and characterized. SMP 6.1 was purified from the culture supernatant by ammonium sulfate precipitation,
acetone fractional precipitation, and preparative isoelectric focusing. SMP 6.1 has a molecular mass of approximately 50 900 Da
by sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE). The following substrates were hydrolyzed: casein,
bovine serum albumin, and hide powder. SMP 6.1 has the characteristics of a metalloprotease, a pH optimum of 10.0, and a temperature
optimum of 42° C. The isoelectric point of the protease is 6.1. Restoration of proteolytic activity by in-gel renaturation
after SDS-PAGE indicates a single polypeptide chain. SMP 6.1 is inhibited by EDTA (9 μg/ml) and not inhibited by antipain
dihydrochloride (120 μg/ml), aprotinin (4 μg/ml), bestatin (80 μg/ml), chymostatin (50 μg/ml), E-64 (20 μg/ml), leupeptin
(4 μg/ml), Pefabloc SC (2000 μg/ml), pepstatin (4 μg/ml), phosphoramidon (660 μg/ml), or phenylmethylsulfonyl fluoride (400
μg/ml). SMP 6.1 retains full activity in the presence of SDS (1% w/v), Tween-20 (1% w/v), Triton X-100 (1% w/v), ethanol (5%
v/v), and 2-mercaptoethanol (0.5% v/v). The extracellular metalloprotease SMP 6.1 differs from the serratiopeptidase (Sigma)
produced by S. marcescens ATCC 27117 in the following characteristics: isoelectric point, peptide mapping and nematolytic properties.
Received: 22 November 1996 / Received revision: 27 February 1997 / Accepted: 7 March 1997 相似文献
5.
G McMahan W Yeh M N Marshall M Olsen S Sananikone J Y Wu D E Block J S VanderGheynst 《Journal of industrial microbiology & biotechnology》2001,26(3):151-155
Benomyl-resistant (BR) and wild-type (WT) strains of Fusarium lateritium were examined for their tolerance to benomyl on potato dextrose agar (PDA) containing benomyl and control of the Eutypa lata in grapevine bioassays. The WT strain grew on PDA containing 1 μg/ml benomyl at 13, 26 and 29°C. The BR strain grew on PDA
containing 10 μg/ml benomyl at 4°C, on PDA containing 100 μg/ml benomyl at 29°C, and on PDA containing 1000 μg/ml benomyl
at 13 and 26°C. The BR strain was also able to colonize grapevine segments and control E. lata in the presence of 1000 μg/ml benomyl. Both strains were amenable to production via liquid fermentation and both achieved 100% control of E. lata in grapevine bioassays. Neither the duration of fermentation nor incubation temperature during grapevine bioassays influenced
the efficacy of either strain against E. lata. The results suggest that application of BR F. lateritium alone or in combination with benomyl may provide good control of E. lata. Journal of Industrial Microbiology & Biotechnology (2001) 26, 151–155.
Received 22 December 1999/ Accepted in revised form 20 October 2000 相似文献
6.
The bacterial strains resistant to pentachlorophenol (PCP) and hexavalent chromium [Cr(VI)] were isolated from treated tannery
effluent of a common effluent treatment plant. Most of the physico-chemical parameters analyzed were above permissible limits.
Thirty-eight and four bacterial isolates, respectively were found resistant to >50 μg/ml concentration of [Cr(VI)] and the
same level of PCP. Out of the above 42 isolates, only one was found simultaneously tolerant to higher levels of both PCP (500 μg/ml)
and Cr(VI) (200 μg/ml), and hence was selected for further studies. To the best of our knowledge, this is the first report
in which a native bacterial isolate simultaneously tolerant to such a high concentrations of Cr(VI) and PCP has been reported.
The culture growth was best at 0.4% (w/v) glucose as an additional carbon source and 0.2% (w/v) ammonium chloride as a nitrogen
source. The growth results with cow urine as a nitrogen source were comparable with the best nitrogen source ammonium chloride.
The isolate exhibited resistance to multiple heavy metals (Pb, As, Hg, Zn, Co & Ni) and to antibiotics nalidixic acid and
polymixin-B. The efficacy of bacterial isolate for growth, PCP degradation (56.5%) and Cr(VI) bioremediation (74.5%) was best
at 48 h incubation. The isolate was identified as Bacillus sp. by morphological and biochemical tests. The 16S rDNA sequence analysis revealed 98% homology with Bacillus cereus. However, further molecular analysis is underway to ascertain its likelyhood of a novel species. 相似文献
7.
J. Mitsuhashi T. D. C. Grace D. F. Waterhouse 《Entomologia Experimentalis et Applicata》1970,13(3):327-341
Serial dilutions of 20 insecticides were examined for their effects on the growth of insect cells cultivated in vitro. No differences in susceptibility were found for cells derived from the moth Antheraea eucalypti and the mosquito Aedes aegypti.Rotenone was the most effective inhibitor investigated, decreasing the rate of cell division at 0.001 g/ml. Malathion and diazinon first showed effects at 12 g and 112/ml respectively. Toxicants first effective at 10 g/ml included pp-DDT, dieldrin, pyrethrins and sodium arsenate; at 100 g/ml they included lindane and carbaryl; at 1000 g/ml only nicotine sulphate.The majority of insecticides tested (principal exception rotenone) were very much more toxic to last instar A. aegypti larvae than to the insect cells, suggesting that the functions of highly organized tissues are more readily interfered with than those of individual cell types comprising them.
Zusammenfassung Verdünnungsserien von 20 Insektiziden wurden auf ihren Effekt auf das Wachstum von in vitro kultivierten Insektenzellen untersucht. Die untersuchten Zellen stammten aus Kulturen von Ovariolen von Antheraea eucalypti-Puppen und von Gewebe von Aedes aegypti-Larven. Rotenon erwies sich als das wirksamste Insektizid: es verlangsamte die Zellteilung in einer Konzentration von 0.001 g/ml. Malathion wurde erst in einer Konzentration von 12 g/ml wirksam, Diazinon bei 112 g/ml. Mehrere Insektizide zeigten erste Wirksamkeit bei 10 g/ml; diese waren: pp-DDT, pp-DDD, pp-DDE, Methoxychlor, Aldrin, Dieldrin, Pyrethrine, Allethrin und Natriumarsenat. Insektizide mit einer ersten Wirksamkeit bei 100 g/ml waren Lindan, Isolan, Dimetilan, Carbaryl, DNOC und Piperonylbutoxid. Nikotinsulfat war erst bei 1 mg/ml oder bei höheren Konzentrationen wirksam. Zwischen den Antheraea- und Aedes-Zellen wurde kein Unterschied in der Empfindlichkeit gegen die verschiedenen Insektizide gefunden. Bei niedrigen Konzentrationen zeigten Malathion und Natriumarsenat erst nach dem 4. Tag bedeutendere Effekte. Ein schwacher synergistischer Effekt wurde beim Mischen von Pyrethrinen mit Piperonylbutoxid in niedrigen Konzentrationen beobachtet, nicht aber bei hohen Konzentrationen.Bei der Mehrzahl (17 von 19) der Insektizide waren die Zellen in 10 bis 10.000 mal höheren Insektizid-Konzentrationen zu überleben fähig als A. aegypti-Larven im letzten Stadium. Rotenon war das einzige Insektizid, dessen Toxizität auf Zellen stärker war (10.000 Mal) als auf intakte Larven.相似文献
8.
Production of high yields of arachidonic acid in a fed-batch system by Mortierella alpina ATCC 32222
Of six strains of Mortierella tested, Mortierella alpina ATCC 32222 produced the highest yields of arachidonic acid. Supplementation of soy flour (1% w/v) and vegetable oils (1%
v/v) significantly increased the biomass, lipid content and arachidonic acid level. Replacement of NaNO3 with corn steep liquor (1% w/v) also improved arachidonic acid production. A fed-batch culture system at 25 °C, producing
a high biomass (52.4 g/l) and arachidonic acid content (9.1 g/l) in 8␣days, was developed. A fed-batch system at low temperature
(15 °C) gave even higher arachidonic acid levels (11.1 g/l) in 11 days.
Received: 28 October 1996 / Received revision: 3 March 1997 / Accepted: 7 March 1997 相似文献
9.
Sclerotia and mycelium ofPhymatotrichum omnivorum were exposed to anhydrous ammonia (NH3) and then observed with an electron microscope in order to determine the effects of the NH3 treatment on the fungal membranes. Sclerotia were exposed to four rates of NH3: 28, 56, 84, and 112μg NH3/ml of air for 24 hours. At 28μg/ml, the plasmalemma became wavy and the mitochondrial cristae began to swell and disperse. At 56μg NH3/ml the plasmalemma showed breakage and formation of vesicles, and all other membrane systems within the cell were broken
and distorted. All membranes were totally disrupted and no organelles were recognizable at 84μg NH3/ml.
Mycelium was exposed to 2, 4, 8, 20, and 40μg NH3/ml for one minute. Damage to cell membranes was not observed at NH3 conc. up to 4μg/ ml. At 8μg NH3/ml the plasmalemma was broken and the mitochondria were disrupted. At 20μg/ ml and above, all internal organization was destroyed. 相似文献
10.
M Ozkan SG Desai Y Zhang DM Stevenson J Beane EA White ML Guerinot LR Lynd 《Journal of industrial microbiology & biotechnology》2001,27(5):275-280
Characteristics of 13 newly isolated thermophilic, anaerobic, and cellulolytic strains were compared with previously described
strains of Clostridium thermocellum: ATCC 27405 and JW20 (ATCC 31549). Colony morphology, antibiotic sensitivity, fermentation end-products, and cellulose degradation
were documented. All 13 strains were sensitive to erythromycin (5 μg/ml) and chloramphenicol (25 μg/ml), and all strains but
one were sensitive to kanamycin (20 μg/ml). Polymerase chain reaction (PCR) amplification using primers based on gene sequences
from C. thermocellum ATCC 27405 was successful for all 13 strains in the case of the hydrogenase gene and 11 strains in the case of phosphotransacetylase/acetate
kinase genes. Ten strains amplified a product of the expected size with primers developed to be specific for C. thermocellum 16SrRNA primers. Two of the 13 strains did not amplify any product with the PCR primers designed for the phosphotransacetylase/acetate
kinase and 16SrRNA primers. A MboI-like GATC- recognizing restriction activity was present in all of the five strains examined. The results of this study have
several positive implications with respect to future development of a transformation system for cellulolytic thermophiles.
Journal of Industrial Microbiology & Biotechnology (2001) 27, 275–280.
Received 12 September 2000/ Accepted in revised form 20 November 2000 相似文献
11.
Anju Arora Sudhir Saxena Dinesh Kumar Sharma 《World journal of microbiology & biotechnology》2006,22(2):97-100
Azolla, an aquatic fern is ideal candidate for exploitation in constructed wetlands for treating metal-contaminated wastewaters. This study demonstrates the potential of Azolla spp. namely A. microphylla, A. pinnata and A.␣filiculoides to tolerate Cr ions in the growth environment and bioconcentrate them. These species could grow in presence of up to 10 μg ml−1 Cr and showed biomass production 30–70% as compared to controls. Nitrogenase activity was not affected at 1–5 μg ml−1 but at higher concentrations it diminished. There was no growth at higher concentrations of chromium. However, the necrosed biomass harvested from treatments containing higher concentrations of chromium, accumulated Cr to the levels 5000–15,000 μg g−1. At increased levels of Cr, the metal was accumulated in higher amount in dry biomass. Bioconcentration Factor (BCF) ranged between 243 and 4617 for the three species. A. microphylla showed highest bioconcentration potential. Thus, these Azolla spp. can be exploited for treatment of tannery and other Cr contaminated wastewaters. 相似文献
12.
Antimicrobial Butyrolactone I Derivatives from the Ecuadorian Soil Fungus Aspergillus terreus Thorn. var terreus 总被引:1,自引:0,他引:1
M. E. Cazar G. Schmeda-Hirschmann L. Astudillo 《World journal of microbiology & biotechnology》2005,21(6-7):1067-1075
Summary The fungus Aspergillus terreus Thorn var. terreus isolated from an Ecuador soil sample was cultured in liquid and solid media and yielded three main metabolites identified
as terreic acid (1), butyrolactone I (2) and lovastatin (3). The natural products as well as three synthetic butyrolactone I derivatives were assessed for antimicrobial activity against
Gram-positive and Gram-negative bacteria and fungi as well as for seed germination and seedling growth. Furthermore, the compounds
were assessed as inhibitors towards the enzymes acetylcholinesterase, β-glucosidase, and β-glucuronidase. Terreic acid, butyrolactone I, butyrolactone 4′,4′′-diacetate (2.1), and 3′-(3-methylbutyl)-butyrolactone II (2.2) were active towards the phytopathogenic bacteria Erwinia carotovora with IC50 of 5 and 4–18 μg/ml, respectively. Under the same experimental conditions, the IC50 of streptomycin was 1.9 μg/ml. 3′-(3-Methylbutyl)-butyrolactone II was moderately active against Pseudomonas syringae and Botrytis cinerea with IC50 of 21μg/ml and MIC of 15.6 μg/ml, respectively. Butyrolactone I also inhibited germination of the dicot Lactuca sativa with an IC50 of 5 × 10−5 M. The IC50 of reference herbicide acetochlor was 1 × 10−5 M. The effect of 2.2 and 2.3, known as butyrolactone III on Panicum millaceum germination and growth was stronger than that of 2 and 2.1. Reduction of the double bond in the isoprenyl side chain of butyrolactone I increased the antibacterial effect against E. carotovora as well as acetylation. To our best knowledge, this is the first report on the antibacterial effect of butyrolactone derivatives
towards Erwinia carotovora and the phytopathogenic fungus Botrytis cinerea. The butyrolactone I derivative 2.2 presented a moderate inhibitory effect against the enzyme acetylcholinesterase with an IC50 of 47 μg/ml. Under the same experimental conditions, the reference inhibitor galanthamine had an IC50 of 3 μg/ml. 相似文献
13.
Arsenic content of cyanobacterial biomass, soil and water samples from arsenic-contaminated area of eastern India were estimated.
It was found that arsenic content in cyanobacterial biomass (276.9 μg g−1) was more than soil (19.01 μg g−1) or water sample (244.13 μg L−1). Shallow tube well water showed more arsenic (244.13 μg L−1) than deep tube well water (146.13 μg L−1). Arsenic resistant genera recorded from the contaminated area were Oscillatoria princeps, Oscillatoria limosa, Anabaena sp. and Phormidium laminosum. Among these, P. laminosum was isolated and exposed to different concentration of Arsenic in vitro (0.1–100 ppm) to study the toxicity level of arsenic.
Modulation in stress enzymes and stress-related compounds were studied in relation to lipid peroxidase, catalase, super oxide
dismutase (SOD), ascorbate peroxidase (APX), reduced glutathione and carotenoids in arsenic exposed biomass to understand
the resistance mechanism of the genus both in laboratory condition as well as in natural condition. Arsenic content of cyanobacterial
biomass from contaminated area was more (276.9 μg g−1) than laboratory exposed sample (37.17 μg g−1), indicating bioconcentration of arsenic in long-term-exposed natural biomass. Overall, more activity of catalase was recorded
in cyanobacterial biomass of natural condition whereas SOD and APX were at higher level in laboratory culture. 相似文献
14.
Ferreira Nunes AP Martins Teixeira L Reis Bastos CC de Souza Fonseca L Netto dos Santos KR 《Current microbiology》2002,44(6):385-390
Reports of staphylococci with reduced susceptibility to glycopeptides are cause for concern. This study evaluated the susceptibility
of 84 staphylococci clinical isolates to glycopeptides by the disk diffusion, agar dilution, E-test, and BHIA screening methods.
Vancomycin agar dilution showed all strains presented minimum inhibitory concentration (MIC) ranging from 0.5 to 2 μg/ml,
and the E-test showed similar results. Teicoplanin agar dilution test showed MICs ranging from ≤ 0.5 to 2 μg/ml for Staphylococcus aureus and MICs ranging from <0.25 to 32 μg/ml for coagulase-negative Staphylococcus (CNS). Ten CNS isolates presented MICs ranging from 8 to 32 μg/ml for agar dilution and/or E-test. All the staphylococci
were susceptible to vancomycin by the disk diffusion test (DDT), but two CNS isolates presented intermediate resistance to
teicoplanin by the DDT and MICs of susceptibility, with two other CNS strains, teicoplanin-susceptible by the DDT, presented
MICs of intermediate resistance. On the vancomycin-containing agar, 20 CNS isolates were able to grow, but no S. aureus strain. All these isolates showed MICs to teicoplanin (4–32 μg/ml) higher than those isolates that did not grow on the agar
screen plate. PFGE of chromosomal SmaI digests showed a wide diversity of these CNS strains, without any predominance of a single PFGE pattern.
Received: 25 May 2001 / Accepted: 9 July 2001 相似文献
15.
Linezolid is an oxazolidinone compound that has been shown to have impressive antimicrobial activity against a number of Gram-positive
bacteria. It inhibits an initiation step of protein synthesis, and its binding site has been shown to be on the 50S ribosomal
subunit. Linezolid was tested to see whether would interfere with the formation of the 50S subunit in Staphylococcus aureus cells, since a number of other 50S-specific antibiotics have this second inhibitory function. Linezolid inhibited protein
synthesis in S. aureus cells with an IC50 of 0.3 μg/ml. A concentration-dependent decline in cell number with an increase in generation time was found. Pulse-chase
labeling studies revealed a specific inhibitory effect on 50S particle formation, with no effect on 30S subunit assembly.
The compound inhibited 50S synthesis with an IC50 of 0.6 μg/ ml, indicating an equivalent effect on translation and particle assembly. A postantibiotic effect of 1 h was found
when cells were initially treated with the drug at 2 μg/ ml. 50S particle numbers recovered more rapidly than translational
capacity, consistent with the increase in viable cell numbers. The inhibitory activities of this novel antimicrobial agent
in cells are discussed.
Received: 28 June 2001 / Accepted: 27 August 2001 相似文献
16.
Comparison of microporous and nonporous membrane bioreactor systems for the treatment of BTEX in vapor streams 总被引:1,自引:0,他引:1
Attaway H Gooding CH Schmidt MG 《Journal of industrial microbiology & biotechnology》2002,28(5):245-251
Increased regulatory constraints on industrial releases of atmospheric volatile organic compounds (VOCs) have resulted in
an interest in using biofilters, bioscrubbers and air/liquid membranes for treatment of vapor phase waste streams. In this
report, we describe the comparison of the use of two fundamentally different types of membrane module systems that allow the
rapid diffusion of vapor phase aromatics and oxygen to an active biofilm for subsequent biodegradation. One system used a
commercial membrane module containing microporous polypropylene fibers while the other used a nonporous silicone tubing membrane
module for the delivery of substrate (a mixture of benzene, ethylbenzene, toluene, and xylenes [BTEX]) and electron acceptor
(O2). Tests of the systems under similar conditions with BTEX in the vapor feed stream showed significant performance advantages
for the silicone membrane system. The average surface-area-based BTEX removal rate for the microporous membrane system over
500 h of operation was 7.88 μg h−1 cm−2 while the rate for the silicone membrane system was 23.87 μg h−1 cm−2. The percentages of BTEX removal were also consistently better in the silicone membrane system versus the microporous system.
Part of the performance problem associated with the microporous membrane system appeared to be internal water condensation
and possible plugging of the pores with biomass over time that could not be resolved with vapor phase backflushing. Journal of Industrial Microbiology & Biotechnology (2002) 28, 245–251 DOI: 10.1038/sj/jim/7000235
Received 17 August 2001/ Accepted in revised form 03 December 2001 相似文献
17.
Toxicity of Hexavalent Chromium and Its Reduction by Bacteria Isolated from Soil Contaminated with Tannery Waste 总被引:8,自引:0,他引:8
An Arthrobacter sp. and a Bacillus sp., isolated from a long-term tannery waste contaminated soil, were examined for their tolerance to hexavalent chromium
[Cr(VI)] and their ability to reduce Cr(VI) to Cr(III), a detoxification process in cell suspensions and cell extracts. Both
bacteria tolerated Cr(VI) at 100 mg/ml on a minimal salts agar medium supplemented with 0.5% glucose, but only Arthrobacter could grow in liquid medium at this concentration. Arthrobacter sp. could reduce Cr(VI) up to 50 μg/ml, while Bacillus sp. was not able to reduce Cr(VI) beyond 20 μg/ml. Arthrobacter sp. was distinctly superior to the Bacillus sp. in terms of their Cr(VI)-reducing ability and resistance to Cr(VI). Assays with permeabilized (treated with toluene or
Triton X 100) cells and crude extracts demonstrated that the Cr(VI) reduction was mainly associated with the soluble protein
fraction of the cell. Arthrobacter sp. has a great potential for bioremediation of Cr(VI)-containing waste.
Received: 13 June 2002 / Accepted: 13 September 2002 相似文献
18.
This study aimed to evaluate the antioxidant activities of a cultured medicinal fungus—Armillariella mellea (Vahl. ex Fr.) Karst. (AM). Three antioxidant assay systems, namely cytochrome c, xanthine oxidase inhibition, and FeCl2-ascorbic acid stimulated lipid peroxidation in rat tissue homogenate tests, were used. Total flavonoid and phenol contents
of AM extracts were also analyzed. Results showed that both aqueous (AM-H2O) and ethanolic (AM-EtOH) extracts of solid state cultured AM showed antioxidant activities in a concentration-dependent
manner. At concentrations 1–100 μg/ml, the free radical scavenging activity was 73.7–92.1% for AM-H2O, and 60.0–90.8% for AM-EtOH. These extracts also showed an inhibitory effect on xanthine oxidase activity, but with a lesser
potency (IC50 is 9.17 μg/ml for AM-H2O and 7.48 μg/ml for AM-EtOH). In general, AM-H2O showed a stronger antilipid peroxidation activity on different rat’s tissues than AM-EtOH. However, both AM extracts displayed
a weak inhibitory effect on lipid peroxidation in plasma. Interestingly, the antilipid peroxidation activity of AM-H2O (IC50–6.66 μg/ml) in brain homogenate was as good as IC50–5.42 μg/ml. AM-H2O (80.0 mg/g) possessed a significantly higher concentration of total flavonoids than AM-EtOH (30.0 mg/g), whereas no difference
was noted in the total phenol content between these two extracts. These results conclude that AM extracts possess potent free
radical scavenging and antilipid peroxidation activities, especially the AM-H2O in the brain homogenate.
Published in Russian in Prikladnaya Biokhimiya i Mikrobiologiya, 2007, Vol. 43, No. 4, pp. 495–500.
The text was submitted by the authors in English. 相似文献
19.
S. H. Mousavi Z. Tayarani-Najaran M. Asghari H. R. Sadeghnia 《Cellular and molecular neurobiology》2010,30(4):591-598
The serum/glucose deprivation (SGD)-induced cell death in cultured PC12 cells represents a useful in vitro model for the study
of brain ischemia and neurodegenerative disorders. Nigella sativa L. (family Ranunculaceae) and its active component thymoquinone (TQ) has been known as a source of antioxidants. In the present
study, the protective effects of N. sativa and TQ on cell viability and reactive oxygen species (ROS) production in cultured PC12 cells were investigated under SGD
conditions. PC12 cells were cultured in DMEM medium containing 10% (v/v) fetal bovine serum, 100 units/ml penicillin, and
100 μg/ml streptomycin. Cells were seeded overnight and then deprived of serum/glucose for 6 and 18 h. Cells were pretreated
with different concentrations of N. sativa extract (15.62–250 μg/ml) and TQ (1.17–150 μM) for 2 h. Cell viability was quantitated by MTT assay. Intracellular ROS production
was measured by flow cytometry using 2′,7′-dichlorofluorescin diacetate (DCF-DA) as a probe. SGD induced significant cells
toxicity after 6, 18, or 24 h (P < 0.001). Pretreatment with N. sativa (15.62–250 μg/ml) and TQ (1.17–37.5 μM) reduced SGD-induced cytotoxicity in PC12 cells after 6 and 18 h. A significant increase
in intracellular ROS production was seen following SGD (P < 0.001). N. sativa (250 μg/ml, P < 0.01) and TQ (2.34, 4.68, 9.37 μM, P < 0.01) pretreatment reversed the increased ROS production following ischemic insult. The experimental results suggest that
N. sativa extract and TQ protects the PC12 cells against SGD-induced cytotoxicity via antioxidant mechanisms. Our findings might raise
the possibility of potential therapeutic application of N. sativa extract and TQ for managing cerebral ischemic and neurodegenerative disorders. 相似文献
20.
Cui J Goh KK Archer R Singh H 《Journal of industrial microbiology & biotechnology》2007,34(5):393-402
The protein-bound polysaccharides of Coriolus versicolor (CPS) have been reported to stimulate overall immune functions against cancers and various infectious diseases by activating
specific cell functions. A New Zealand isolate (Wr-74) and a patented strain (ATCC-20545) of C. versicolor were compared in this study. The fruit bodies of both strains were grown for visual verification. Both strains were grown
in submerged-culture using an airlift fermentor with milk permeate as the base medium supplemented with glucose, yeast extract
and salt. Metabolic profiles of both strains obtained over 7-day fermentation showed very similar trends in terms of biomass
production (8.9–10.6 mg/ml), amounts of extracellular polysaccharide (EPS) from the culture medium (1150–1132 μg/ml), and
intracellular polysaccharide (IPS) from the mycelium (80–100 μg/ml). Glucose was the dominant sugar in both EPS and IPS, and
the polymers each consisted of three molecular weight fractions ranging from 2 × 106 to 3 × 103 Da. Both the EPS and IPS were able to significantly induce cytokine production (interleukin 12 and γ interferon) in murine
splenocytes in vitro. Highest levels of interleukin 12 (291 pg/ml) and γ interferon (6,159 pg/ml) were obtained from samples
containing Wr-74 IPS (0.06 μg/ml) and ATCC 20545 IPS (0.1 μg/ml), respectively. The results indicated that lower levels of
EPS and IPS generally resulted in higher immune responses than did higher polymer concentrations. 相似文献