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1.
The antimicrobial properties of acetone, methanol, and aqueous extracts of the lichens Lasallia pustulata, Parmelia sulcata, Umbilicaria crustulosa, and Umbilicaria cylindrica were studied comparatively in vitro. Antimicrobial activities of the extracts of different lichens were estimated by the
disk diffusion test for Gram-positive bacteria, Gram-negative bacteria, and fungal organisms, as well as by determining the
MIC (minimal inhibitory concentration). The obtained results showed that the acetone and methanol extracts of Lasallia pustulata, Parmelia sulcata, and Umbilicaria crustulosa manifest antibacterial activity against the majority of species of bacteria tested, in addition to selective antifungal activity.
The MIC of lichen extracts was lowest (0.78 mg/ml) for the acetone extract of Lasallia pustulata against Bacillus mycoides. Aqueous extracts of all of the tested lichens were inactive. Extracts of the lichen Umbilicaria cylindrica manifested the
weakest activity, inhibiting only three of the tested organisms. 相似文献
2.
Dong-Geun?Lee Jin-Won?Hyun Kyong-Ah?Kang Jin-Ok?Lee Sang-Hyun?Lee Bae-Jin?Ha Jong-Myung?Ha Eun?Yeol?Lee Jae-Hwa?Lee
This is the first report on the antitumor and immunostimulating activities ofUlva lactuca. Using the WSM (water-soluble fraction of a methanol extract fromUlva lactuca), a concentration of 140 g/mL was found to inhibit 50% of the human leukemia cell line U937 in growth, while splenocyte growth
was stimulated up to a concentration of 100 μg/mL. In addition, NO production by a macrophage cell line (RAW 264.7) and alkaline
phosphatase activity in mouse splenocytes were both stimulated with 10 μg/mL of WSM. Dose-dependent patterns were observed
on all three cell-lines. Accordingly, the current results indicate thatUlva lactuca may be useful as a natural antitumor and immunostimulating agent. 相似文献
3.
We investigated seasonal variations in allelopathic potential ofArtemisia princeps var.orientalis. Aqueous and meth-anol extracts and volatile substances were prepared in the laboratory from samples collected monthly (April
through October). Their impacts were then assessed on the germination and seedling growth ofLactuca sativa andAchyranthes japonica. The allelopathic potential varied with the time of sample collection and the concentration tested. For example, germination
ofL. sativa was not inhibited by the aqueous extract but seedling growth (shoots and roots) was, with its seasonal effect being significant.
ForA. japonica, seed germination was not inhibited at lower concentrations (except for August samples). However, at higher concentrations
and in certain months (especially July), germination was more negatively affected. The degree of seedling growth inhibition
also differed by month and by extract concentration, with roots being impacted more than shoots. Volatile substances also
had a time-dependent influence on the germination and seedling elongation ofA. japonica. In a separate experiment, the ethyl-acetate and water fractions of a crude methanol extract were prepared monthly fromA. princeps var.orientalis. Here, we examined their antimicrobial activities against three gram-positive bacteria (Bacillus cereus, Bacillus subtilis, andStaphylococcus aureus), two gramnegative bacteria (Escherichia coli andPseudomonas fluorescens), and one lactic acid bacterium,Lactobacillus plantar urn. The ethyl-acetate fraction that was sampled in September was remarkably potent againstB. cereus andB. subtilis, whereas the water fraction collected in August and September showed great antimicrobial activity against the grampositive
and -negative bacteria. In contrast,L. plantarum was not inhibited by the water fraction, regardless of the sampling month. Likewise, the ethyl-acetate and water fractions
collected in April and October had the lowest levels of antimicrobial activity. 相似文献
4.
Twenty six Rhizobium strains isolated from root nodules of Sesbania sesban were studied for chitinase activity on chitin agar plates. Among them, only 12 strains showed chitinase activity. The strain
showing the highest chitinase activity was selected based on maximum clear zone/colony size ratio on chitin agar plates and
chitinase activity in culture filtrate. The strain was identified as Rhizobium sp. which showed a high degree of similarity with Rhizobium radiobacter (= Agrobacterium radiobacter). The cultural and nutritional conditions were optimized for maximum chitinase activity. The Rhizobium sp. exhibited maximum chitinase activity after 36 h of incubation, at neutral pH. Among the different nutritional sources,
arabinose and yeast extract were found to be good inducers for chitinase activity. Rhizobium sp. could degrade and utilize dead mycelia of Aspergillus flavus, Aspergillus niger, Curvularia lunata, Fusarium oxysporum and Fusarium udum. 相似文献
5.
Gilsang Jeong Kyeongyong Lee Jiyoung Choi Seokjo Hwang Byeongdo Park Wontae Kim Youngcheol Choi Ingyun Park Jonggill Kim 《Journal of microbiology (Seoul, Korea)》2009,47(1):28-32
Sex ratio distorting endosymbionts induce reproductive anomalies in their arthropod hosts. They have recently been paid much
attention as firstly texts of evolution of host-symbiont relationships and secondly potential biological control agents to
control arthropod pests. Among such organisms, Wolbachia and Cardinium bacteria are well characterized. This study aims at probing such bacteria in the Osmia community to evaluate their potential utilization to control arthropod pests. Among 17 PCR tested species, Osmia cornifrons and a parasitic fly are infected with Wolbachia and a mite species is infected with Cardinium. Phylogenetic tree analyses suggest that horizontal transfer of the bacteria occurred between phylogenetically distant hosts. 相似文献
6.
Purpose of the present study was to evaluate alkaloid profile of the aerial parts of Lupinus angustifolius growing in Turkey by capillary gas chromatography-mass spectrometry (GC-MS). Fifteen alkaloids were identified by capillary
GC-MS. 13α-Hydroxylupanine (50.78%) and lupanine (23.55%) were determined as the main alkaloids in the aerial parts of L. angustifolius. Ammodendrine, isoangustifoline, tetrahydrorhombifoline, angustifoline, α-isolupanine, 5,6-dehydrolupanine, 11,12-dehydrolupanine,
13α-acetoxylupanine, 13α-isovaleroyloxylupanine, 13α-valeroyloxylupanine, 13α-tigloyloxylupanine, 13α-cis-cinnamoyloxylupanine and 13α-cis-cinnamoyloxy-17-oxolupanine were identified as the minor alkaloids of the plant. Furthermore, antibacterial and antifungal
activities of L. angustifolius alkaloid extract were tested against standard strains of the following bacteria; Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus as well as the fungi; Candida albicans and C. krusei. The alkaloid extract showed significant activity on B. subtilis, S. aureus and P. aeruginosa while it was weakly active on E. coli. On the other hand, the extract possessed moderate activity against C. albicans and C. krusei. 相似文献
7.
Young Tae Kim Kang Seon Lee Moon Jung Kim Seung Bum Kim 《Journal of microbiology (Seoul, Korea)》2009,47(1):33-39
The effects of Chinese cabbage (Brassica rapa subsp. pekinensis) carrying cry1AC derived from Bacillus thuringiensis (Bt) on leaf bacterial community were examined by analyzing the horizontal transfer of trans-gene fragments from plants to
bacteria. The effect of plant pathogenic bacteria on the gene transfer was also examined using Pseudomonas syringae pathovar. maculicola. The frequency of hygromycin-resistant bacteria did not alter in Bt leaves, though slight increase was observed in Pseudomonas-infected Bt leaves with no statistical significance. The analysis of bacterial community profiles using the denaturing gradient
gel electrophoresis (DGGE) fingerprinting indicated that there were slight differences between Bt and control Chinese cabbage,
and also that infected tissues were dominated by P. syringae pv. maculicola. However, the cultured bacterial pools were not found to contain any transgene fragments. Thus, no direct evidence of immediate
gene transfer from plant to bacteria or acquisition of hygromycin resistance could be observed. Still, long-term monitoring
on the possibility of gene transfer is necessary to correctly assess the environmental effects of the Bt crop on bacteria. 相似文献
8.
Duldhardt I Nijenhuis I Schauer F Heipieper HJ 《Applied microbiology and biotechnology》2007,77(3):705-711
The effect of seven important pollutants and three representative organic solvents on growth of Thauera aromatica K172, as reference strain for nitrate-reducing anaerobic bacteria, was investigated. Toxicity in form of the effective concentrations
(EC50) that led to 50% growth inhibition of potential organic pollutants such as BTEX (benzene, toluene, ethylbenzene, and
xylene), chlorinated phenols and aliphatic alcohols on cells was tested under various anaerobic conditions. Similar results
were obtained for Geobacter sulfurreducens and Desulfococcus multivorans as representative for Fe3+-reducing and sulphate-reducing bacteria, respectively, leading to a conclusion that anaerobic bacteria are far more sensitive
to organic pollutants than aerobic ones. Like for previous studies for aerobic bacteria, yeast and animal cell cultures, a
correlation between toxicity and hydrophobicity (log P values) of organic compounds for different anaerobic bacteria was ascertained. However, compared to aerobic bacteria, all
three tested anaerobic bacteria were shown to be about three times more sensitive to the tested substances. 相似文献
9.
KiBeom Lee 《World journal of microbiology & biotechnology》2007,23(9):1317-1320
Lactobacillus
delbrueckii subsp. lactis strains were developed having increased activity, by gradually acclimatizing the bacteria to acidic conditions over repeated
batch culture. Cells from one batch culture were used as the inoculum for the subsequent batch culture and thereby an adapted
strain of Lactobacillus was obtained showing improved lactic acid productivity, cell growth and total glucose utilization. Furthermore, the acclimatized
cells used significantly less nitrogen for a given level of lactic acid production, which is significant from an industrial
point of view. The developed procedure decreases fermentation time and nutrient use, leading to reduced operation costs, while
providing a lactic acid yield superior to previously reported methods. 相似文献
10.
Inui M Suda M Kimura S Yasuda K Suzuki H Toda H Yamamoto S Okino S Suzuki N Yukawa H 《Applied microbiology and biotechnology》2008,77(6):1305-1316
A recombinant butanol pathway composed of Clostridium acetobutylicum ATCC 824 genes, thiL, hbd, crt, bcd-etfB-etfA, and adhe1 (or adhe) coding for acetyl-CoA acetyltransferase (THL), β-hydroxybutyryl-CoA dehydrogenase (HBD), 3-hydroxybutyryl-CoA dehydratase
(CRT), butyryl-CoA dehydrogenase (BCD), butyraldehyde dehydrogenase (BYDH), and butanol dehydrogenase (BDH), under the tac promoter control was constructed and was introduced into Escherichia coli. The functional expression of these six enzymes was proved by demonstrating the corresponding enzyme activities using spectrophotometric,
high performance liquid chromatography and gas chromatography analyses. The BCD activity, which was not detected in E. coli previously, was shown in the present study by performing the procedure from cell extract preparation to activity measurement
under anaerobic condition. Moreover, the etfA and etfB co-expression was found to be essential for the BCD activity. In the case of BYDH activity, the adhe gene product was shown to have higher specificity towards butyryl-CoA compared to the adhe1 product. Butanol production from glucose was achieved by the highly concentrated cells of the butanologenic E. coli strains, BUT1 with adhe1 and BUT2 with adhe, under anaerobic condition, and the BUT1 and BUT2 strains were shown to produce 4 and 16-mM butanol with 6- and 1-mM butyrate
as a byproduct, respectively. This study reports the novel butanol production by an aerobically pregrown microorganism possessing
the genes of a strict anaerobe, Clostridium acetobutylicum. 相似文献
11.
Kim PI Jung MY Chang YH Kim S Kim SJ Park YH 《Applied microbiology and biotechnology》2007,74(5):1103-1111
One strain of Lactobacillus salivarius, two strains of Lactobacillus reuteri and Lactobacillus amylovorus, and two strains of Bifidobacterium thermacidophilum with antagonistic effect against Clostridium perfringens were isolated from porcine gastrointestinal tract. Isolates were assayed for their ability to survive in synthetic gastric
juice at pH 2.5 and were examined for their ability to grow on agar plate containing porcine bile extract. There was a large
variation in the survival of the isolates in gastric juice and growth in the medium containing 0.3% (w/v) bile. L. salivarius G11 and L. amylovorus S6 adhered to the HT-29 epithelial cell line. Cell-free supernatant of L. amylovorus S6 showed higher antagonistic activity as effective as the antibiotics such as neomycin, chlortetracycline, and oxytetracycline
against bacterial pathogens including C. perfringens, Salmonella typhimurium, Staphylococcus aureus, Vibrio cholerae, Edwardsiella tarda, and Aeromonas salmonicida subsp. salmonicida. 相似文献
12.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
13.
We tested the influence of extracts from three medicinal herbs —Salvia miltiorrhiza, Schizandra chinensis, andEugenia caryophyllata — on activity of the nematodeRhabditis elongate. Treatment with f.caryophyllata was most useful, causing the greatest decrease in populations and mobility, but did not have any detrimental effect on the
initial growth of the host microorganism,Escherichia coli. For example, when 0.5 g/L of the extract was added to an inoculated liquid culture, we counted 710 nematodes/mL, with a multiplication
rate 5 times greater than the initial population. This was in contrast to the control sample, which had a count of 1100 nematodes/mL
and a growth ratio of 11. For our field test, nematode mobility in the presence of the extract also decreased, to 6.8 mm/day,
compared with 20 mm/day for the control. Likewise, when 1.0 g/L of the extract was added to the soil, the total number of
nematodes was reduced to only 30- to 40% of the control population. 相似文献
14.
We have investigated the floral ontogeny of Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis (of the eucalypt group, Myrtaceae) using scanning electron microscopy and light microscopy. Several critical characters for establishing relationships between these genera and to the eucalypts have been determined. The absence of compound petaline primordia in Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis excludes these taxa from the eucalypt clade. Post-anthesis circumscissile abscission of the hypanthium above the ovary in Stockwellia, Eucalyptopsis and Allosyncarpia is evidence that these three taxa form a monophyletic group; undifferentiated perianth parts and elongated fusiform buds are characters that unite Stockwellia and Eucalyptopsis as sister taxa. No floral characters clearly associate Arillastrum with either the eucalypt clade or the clade of Stockwellia, Eucalyptopsis and Allosyncarpia.We gratefully acknowledge Clyde Dunlop and Bob Harwood (Northern Territory Herbarium) for collecting specimens of Allosyncarpia, and Bruce Gray (Atherton) for collecting specimens of Stockwellia. The Australian National Herbarium (CANB) kindly lent herbarium specimens of Eucalyptopsis for examination. This research was supported by a University of Melbourne Research Development Grant to Andrew Drinnan. 相似文献
15.
Stefanie Kimbacher Ingrid Gerstl Branko Velimirov Sylvia Hagemann 《Molecular genetics and genomics : MGG》2009,282(2):165-172
P transposons belong to the eukaryotic DNA transposons, which are transposed by a cut and paste mechanism using a P-element-coded transposase. They have been detected in Drosophila, and reside as single copies and stable homologous sequences in many vertebrate species. We present the P elements Pcin1, Pcin2 and Pcin3 from Ciona intestinalis, a species of the most primitive chordates, and compare them with those from Ciona savignyi. They showed typical DNA transposon structures, namely terminal inverted repeats and target site duplications. The coding
region of Pcin1 consisted of 13 small exons that could be translated into a P-transposon-homologous protein. C. intestinalis and C. savignyi displayed nearly the same phenotype. However, their P elements were highly divergent and the assumed P transposase from C. intestinalis was more closely related to the transposase from Drosophila melanogaster than to the transposase of C. savignyi. The present study showed that P elements with typical features of transposable DNA elements may be found already at the base of the chordate lineage.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
16.
17.
Various solvent extracts of the lichen Usnea ghattensis showed good antioxidant activity. A methanol extract prevented lipid peroxidation by 87% followed by 65% in Trolox at 20 μg/ml. It also showed superoxide anion scavenging activity and free radical scavenging activity 56% and 73%, respectively. The known antioxidants butylated hydroxytoluene (BHT), butylated hydroxyanisol (BHA) and quercetin at similar concentrations showed superoxide anion scavenging activity of 68, 59 and 47% and free radical scavenging activity 83, 77 and 69%, respectively. In addition, these extracts were inhibitory against Bacillus licheniformis, Bacillus megaterium, Bacillus subtilis and Staphylococcus aureus with MIC values of 5–10 μg/ml.Received after revisions 10 May 2005 相似文献
18.
One solution to the global crisis of antibiotic resistance is the discovery of novel antimicrobial compounds for clinical
application. Marine organisms are an attractive and, as yet, relatively untapped resource of new natural products. Cell extracts
from the marine diatom, Phaeodactylum tricornutum, have antibacterial activity and the fatty acid, eicosapentaenoic acid (EPA), has been identified as one compound responsible
for this activity. During the isolation of EPA, it became apparent that the extracts contained further antibacterial compounds.
The present study was undertaken to isolate these additional antibacterial factors using silica column chromatography and
reverse-phase high-performance liquid chromatography. Two antibacterial fractions, each containing a pure compound, were isolated
and their chemical structures were investigated by mass spectrometry and nuclear magnetic resonance spectroscopy. The antibacterial
compounds were identified as the monounsaturated fatty acid (9Z)-hexadecenoic acid (palmitoleic acid; C16:1 n-7) and the relatively unusual polyunsaturated fatty acid (6Z, 9Z, 12Z)-hexadecatrienoic acid (HTA; C16:3 n-4). Both are active against Gram-positive bacteria with HTA further inhibitory to the
growth of the Gram-negative marine pathogen, Listonella anguillarum. Palmitoleic acid is active at micro-molar concentrations, kills bacteria rapidly, and is highly active against multidrug-resistant
Staphylococcus aureus. These free fatty acids warrant further investigation as a new potential therapy for drug-resistant infections. 相似文献
19.
Shahriar Saiedian Ezzatollah Keyhani Jacqueline Keyhani 《Acta Physiologiae Plantarum》2007,29(5):463-471
Crocus sativus L., cultivated since ancient times as the source of saffron, is a triploid plant that can be propagated only via its corms
which undergo a period of dormancy. Understanding the processes taking place in the corm is essential to preserve the plant
and improve its quality. Color and taste being of prime importance in the quality of the saffron spice, knowledge on polyphenol
oxidase (PPO) activity in the plant is of particular interest given the role of the enzyme in fruit and vegetable browning
during processing and during the storage of processed food. In this paper, PPO activity was investigated for the first time
in extracts obtained from dormant C. sativus L. corms. PPO activity was detectable using l-DOPA, pyrogallol, catechol or p-cresol as substrate, each being oxidized to its corresponding o-quinone; no activity was detectable with l-tyrosine, tyramine or phenol as substrate. Two pH optima, respectively at 4.5 and 6.7, were observed with all substrates
and a third one, at 8.5, was found with l-DOPA and p-cresol. Kinetics parameters studied at pH 6.7 indicated the highest catalytic efficiency (in units mg−1 prot mM−1) with pyrogallol: 150, then catechol: 39, l-DOPA: 6.4 and p-cresol: 4.6. The enzymatic activity was inhibited by 50% in the presence of 0.22, 0.35, 0.5 and 0.7 mM kojic acid with, respectively,
catechol, pyrogallol, p-cresol and l-DOPA as substrate. When stained for PPO activity, non-denaturing gel electropherograms of extract revealed three distinct
bands, indicating the presence of multiple isoenzymes in dormant C. sativus L. corms. 相似文献
20.
Horton CE Huang KX Bennett GN Rudolph FB 《Journal of industrial microbiology & biotechnology》2003,30(7):427-432
Esters are formed by the condensation of acids with alcohols. The esters isoamyl acetate and butyl butyrate are used for food and beverage flavorings. Alcohol acetyltransferase is one enzyme responsible for the production of esters from acetyl-CoA and different alcohol substrates. The genes ATF1 and
ATF2, encoding alcohol acetyltransferases from the yeast Saccharomyces cerevisiae have been sequenced and characterized. The production of acids and alcohols in mass quantities by the industrially important Clostridium acetobutylicum makes it a potential organism for exploitation of alcohol acetyltransferase activity. This report focuses on the heterologous expression of the alcohol acetyltransferases in Escherichia coli and C. acetobutylicum.
ATF1 and ATF2 were cloned and expressed in E. coli and ATF2 was expressed in C. acetobutylicum. Isoamyl acetate production from the substrate isoamyl alcohol in E. coli and C. acetobutylicum cultures was determined by head-space gas analysis. Alcohol acetyltransferase I produced more than twice as much isoamyl acetate as alcohol acetyltransferase II when expressed from a high-copy expression vector. The effect of substrate levels on ester production was explored in the two bacterial hosts to demonstrate the efficacy of utilizing ATF1and ATF2 in bacteria for ester production. 相似文献