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1.
An occurrence of the toxigenic fungi producing aflatoxins and ochratoxin A in food was investigated in the study (“MYCOMON”) in years 1999–2001. Twenty five commodities were purchased from retail in twelve collection places in the Czech Republic (300 food samples together). The presence of potentially toxigenic fungiAspergillus flavus was observed in 28% of the sampled food (black pepper, black tea, caraway seeds, fine flour, fruit tea, oat flakes) in the year 1999, in 17% of the sampled food (black pepper, black tea, caraway seeds, fine flour, fruit tea, oat flakes) in the year 2000 and in 18% of the sampled food (black pepper, black tea, caraway seeds, fine flour, fruit tea, oat flakes) in the year 2001.Aspergillus tamarii (aflatoxins producer) was found in black pepper samples (25%) in year 1999, in black pepper samples and black tea (25%) in year 2000 and in black pepper samples and black tea (21%) in year 2001.Aspergillus parasiticus andAspergillus nomius were not isolated.Aspergillus sectionNigri (potential producer of ochratoxin A) was detected in some food (black pepper, black tea, caraway seeds, fine flour, fruit tea, raisins, sweet red pepper).Penicillium verrucosum and Aspergillus ochraceus were not isolated from the tested food.  相似文献   

2.
Aims: Phytophthora capsici is a major pathogen of black pepper and zoospores play an important role in the infection process. Fluorescent pseudomonads that produce biosurfactants with zoosporicidal activities were isolated from the black pepper rhizosphere in Vietnam, and their genotypic diversity and potential to control Phy. capsici root rot was determined. Methods: Biosurfactant‐producing pseudomonads were genotypically and biochemically characterized by BOX‐polymerase chain reaction (PCR), 16S‐rDNA sequencing, reverse‐phase‐high‐performance liquid chromatography and liquid chromatography‐masss spectrometry analyses. Results: Biosurfactant‐producing fluorescent pseudomonads make up c. 1.3% of the culturable Pseudomonas population in the rhizosphere of black pepper. Although BOX‐PCR revealed substantial genotypic diversity, the isolates were shown to produce the same biosurfactants and were all identified as Pseudomonas putida. When applied to black pepper stem cuttings, several of the biosurfactant‐producing strains provided significant disease control. In absence of the disease, several of the bacterial strains promoted shoot and root growth of black pepper stem cuttings. Conclusions: Biosurfactant‐producing pseudomonads indigenous to the rhizosphere of black pepper plants are genotypically diverse and provide a novel resource for the control of Phy. capsici root rot and growth promotion of black pepper stem cuttings. Significance and Impact of the Study: The results of this study provide a strong basis for further development of supplementary strategies with antagonistic bacteria to control foot and root rot of black pepper and to promote plant growth.  相似文献   

3.
Aspergillus parasiticus Speare NRRL 2999 growth and aflatoxin production in black and white pepper and the penetration of the fungus in black pepper corn over various incubation periods were studied. Also, the effects of piperine and pepper oil on growth and aflatoxin production were studied. Under laboratory conditions, black and white pepper supported aflatoxin production (62.5 and 44 ppb (ng/g), respectively) over 30 days of incubation. Fungal growth measured in terms of chitin was considerably less in white pepper than in black pepper. A histological study of black pepper corn showed the fungus penetrating up to the inner mesocarp and establishing itself in the middle mesocarp. Piperine and pepper oil were found to inhibit fungal growth and toxin production in a dose-dependent manner. Thus, both black and white pepper could be considered as poor substrates for fungal growth and aflatoxin production.  相似文献   

4.
The occurrence of toxigenic fungi producing aflatoxins and ochratoxin A in foodstuffs was studied in the Czech Republic. Twenty five commodities were collected at twelve collection places in the Czech Republic (300 food samples). The presence of potentially toxigenicAspergillus flavus was observed in 28% of the sampled foods (black pepper, caraway seeds, fruit tea, black tea, oat flakes, fine flour, rolled oat flakes and semolina) in the year 1999, and in 25% of the sampled foods (black pepper, black tea, fine flour) in the year 2000.A tamarii (aflatoxins producer) was found in 3 black pepper samples (25%) in both years. Aflatoxins were detected in black pepper and caraway seed samples in the year 1999 and in sweet red pepper in the year 2000.A parasiticus andA nomius were not isolated. Aspergillus section Nigri (potential producer of ochratoxin A) was detected in some foodstuffs. Ochratoxin A was detected in raisins.Penicillium verrucosum andA ochraceus were not isolated from foodstuffs.  相似文献   

5.
Aspergillus parasiticus Speare NRRL 2999 growth and aflatoxin production in black and white pepper and the penetration of the fungus in black pepper corn over various incubation periods were studied. Also, the effects of piperine and pepper oil on growth and aflatoxin production were studied. Under laboratory conditions, black and white pepper supported aflatoxin production (62.5 and 44 ppb (ng/g), respectively) over 30 days of incubation. Fungal growth measured in terms of chitin was considerably less in white pepper than in black pepper. A histological study of black pepper corn showed the fungus penetrating up to the inner mesocarp and establishing itself in the middle mesocarp. Piperine and pepper oil were found to inhibit fungal growth and toxin production in a dose-dependent manner. Thus, both black and white pepper could be considered as poor substrates for fungal growth and aflatoxin production.  相似文献   

6.
Truong NV  Liew EC  Burgess LW 《Fungal biology》2010,114(2-3):160-170
Phytophthora foot rot of black pepper caused by Phytophthora capsici is a major disease of black pepper (Piper nigrum) throughout Vietnam. To understand the population structure of P. capsici, a large collection of P. capsici isolates from black pepper was studied on the basis of mating type, random amplified microsatellites (RAMS) and repetitive extragenic palindromic (REP) fingerprinting. Two mating types A1 and A2 were detected in four provinces in two climatic regions, with A1:A2 ratios ranging from 1:3 to 1:5. In several instances A1 and A2 mating types were found to co-exist in the same farm or black pepper pole, suggesting the potential for sexual reproduction of P. capsici in the field in Vietnam although its contribution to disease epidemics is uncertain. RAMS and REP DNA fingerprinting analysis of 118 isolates of P. capsici from black pepper showed that the population was genetically more diverse where two mating types were found, although the overall genetic diversity was low with most of the isolates belonging to one clonal group. The implication of these findings is discussed. The low diversity among isolates suggests that the P. capsici population may have originated from a single source. There was no genetic differentiation of isolates from different climatic regions. In addition to the large clonal group, several isolates with unique RAMS/REP phenotypes were also detected. Most of these unique phenotypes belonged to the minority A1 mating type. This may have significant implications for a gradual increase in overall genetic diversity.  相似文献   

7.
Marine sponges belonging to the order Haplosclerida are one of the more prolific sources of new natural products possessing various biological activities. The present study examined the cytotoxic and genotoxic potential of ingenamine G, an alkaloid isolated from the Brazilian marine sponge Pachychalina alcaloidifera. Ingenamine G displayed a moderate cytotoxic activity against human proliferating lymphocytes evaluated by the MTT assay (IC(50) 15 microg/mL). The hemolytic assay showed that ingenamine G cytotoxic activity was not related to membrane disruption. The comet assay and chromosome aberration analysis were applied to determine the genotoxic and clastogenic potential of ingenamine G, respectively. Cultured human lymphocytes were treated with 5, 10, 15 and 20 microg/mL of ingenamine G during the G(1), G(1)/S, S (pulses of 1 and 6 h), and G(2) phases of the cell cycle. All tested concentrations were cytotoxic, reduced significantly the mitotic index, and were clastogenic in all phases of the cell cycle, especially in S phase. While an increase in DNA-strand breaks was observed starting with the concentration corresponding to the IC(50). The presence of genotoxicity and polyploidy during interphase and mitosis, respectively, suggests that ingenamine G at high concentrations is clastogenic and indirectly affects the construction of mitotic fuse.  相似文献   

8.
M. Jalili  S. Jinap  S. Radu 《Mycopathologia》2010,170(4):251-258
The concentration of ochratoxin A (OTA) in 120 commercial pepper (84 pre-packed and 36 bulk samples), which consist of local and imported white and black pepper in powder and seed form in Malaysia were determined. The objective of the study was to investigate and compare OTA concentration in black pepper and white pepper being commercialized in Malaysia. Determination method was based on HPLC with fluorescence detection coupled with immunoaffinity column clean-up step. Mobile phase consisted of acetonitrile–water–acetic acid (49.5:49.5:1.0, v/v/v), and flow rate was 1 ml/min. The LOD was 0.02 ng/g, and the average recovery values of OTA ranged from 79.5 to 92.0% in black pepper and 81.2–90.3% in white pepper. A total of 57 samples (47.5%) were contaminated with OTA ranging from 0.15 to 13.58 ng/g. The results showed that there was a significant difference between type of pepper and brands. OTA concentration in black pepper was significantly higher than white pepper (p < 0.05). The highest concentration of ochratoxin, 13.58 ng/g, was detected in a sample of black pepper seed followed by 12.64 ng/g in a sample of black pepper powder, both were bulk samples purchased from open market.  相似文献   

9.
S Palit  A Sharma  G Talukder 《Cytobios》1991,68(273):85-89
Various dilutions (1/10, 1/20, 1/40) of the lethal toxic dose of cobalt chloride, a non-carcinogenic salt, were found to be clastogenic to bone marrow cells of mice when administered orally in vivo. The clastogenic effects, mainly chromosome breaks, increased significantly with increasing concentration. The frequency of cell division was affected only by higher concentrations of the salt.  相似文献   

10.
During a survey of nurseries and plantations of black pepper plants in Quang Tri province in Vietnam during the rainy season of 2007, nine fungal taxa were isolated from the roots of the black pepper plants. Fusarium solani was found in about one out of four black pepper root samples examined but not in the nurseries and also not from black pepper plants younger than five years growing in plantations. Since in these nurseries about one out of two black pepper plants examined had yellow leaves, this observation suggests that another pathogen must be the initial cause of the yellowing of the leaves. A likely pathogenic candidate is M. incognita which was extracted from every single black pepper plant examined in the nurseries. During the same survey, we also observed that F. solani was not isolated from the roots of black pepper plants that did not had yellow leaves and that the percentage of black pepper plants with yellow leaves increased with increased frequency of occurrence of F. solani. This observation indicates that F. solani plays a role in the yellowing of the leaves of black pepper plants in a later stage of the development of the plants. The results of a greenhouse experiment showed the negative effects inoculation with M. incognita alone or in combination with F. solani may have on the percentage of black pepper plants with yellow leaves and on plant growth. No effect of inoculation with F. solani before, at the same time, or two weeks after inoculation with M. incognita on root galling and nematode reproduction was observed.  相似文献   

11.
The relation between the pH of the medium and clastogenic activity was studied in Chinese hamster ovary (CHO) K1 cells in vitro. The pH was adjusted with NaOH, KOH, HCl or H2SO4. No clastogenic activity was observed over the initial pH range of 7.3-10.9 without S9 mix, but a few chromosomal aberrations were induced at pH 10.4 with S9 mix. The frequency of aberrations increased with the increase in amount of S9. At acidic pH, many chromatid breaks were induced at initiatial pH 5.5 or below without S9 mix, and aberrations such as chromatid breaks and chromatid exchanges were induced at initial pH 6.2 or below with S9 mix. Using MES and Bis-Tris as buffers instead of sodium bicarbonate, we observed that aberrations of the chromatid break type were inducible at pH 6.2 or below. These results show that the combination of strong alkalinity and S9 is clastogenic to CHO-K1 cells, and also that weakly acidic media are genetically active. The results indicate that incubations at non-physiological pH might give false-positive responses.  相似文献   

12.
The 1-p-(3-methyltriazeno) benzoic acid potassium salt (MTBA) is a triazeno analogue of dacarbazine, an antineoplastic agent capable of mediating the appearance of new antigenic specificities on cancer cells in mice, a phenomenon described as 'chemical xenogenization' (CX). Recently we reported the clastogenic potential of MTBA on human lymphocytes. Since sister-chromatid exchange (SCE) assay is more sensitive than clastogenic tests, at least at low drug concentrations, we assessed SCE frequencies induced by MTBA on human lymphocytes stimulated by PHA. Drug treatment at 2-500 micrograms/ml was performed in vitro prior to or after PHA addition. SCE values increased significantly in a dose-dependent manner up to 200 micrograms/ml. However, SCE frequencies, as well as chromosome breaks, did not increase dramatically. These data indicate that MTBA concentrations used for CX do not cause severe cytogenetic damage to immune cells at least in vitro.  相似文献   

13.
Housefly is a significant domestic pest, which causes nuisance. The use of insecticides is discouraged to manage housefly; therefore, alternative management strategies are inevitable. The current study investigated the impact of different plant extracts, i.e., Moringa oleifera (moringa), Allium sativum (garlic) and Piper nigrum (black pepper) on biological parameters of house fly. Two different concentrations (i.e., 25 and 50%) of the extracts were blended in larval diet made through mixing of wheat bran, yeast and dried milk powder. The results indicated significant differences for larval duration. Maximum larval duration was recorded for garlic followed by black pepper and moringa, respectively. In case of pupal duration, non-significant differences were observed among plant extracts. Increase rate of oviposition was noticed with moringa at 25% concentration, while decreased oviposition rate was noted for garlic with 50% concentration. Egg hatching percentage remained non-significant for the botanical extracts. The highest survival was observed with moringa, while garlic resulted in the lowest survival. The highest repellency was noticed for garlic followed by black pepper, whereas moringa resulted in the lowest repellency after 30, 60 and 90 min. Prolonged developmental time was observed for bot concentrations of garlic, whereas moringa noted the shortest developmental time. Thus moringa was found to be a promoter of housefly development. Minimum adult emergence was found with both concentrations of garlic followed by 50% concentration of black pepper. The 50% concentration of black pepper promoted the population of adult males, while both concentrations of moringa and 25% concentration of black pepper encouraged the population of female adults. Study outcomes depicted that tested botanical extracts had significant potential for disturbing biological parameters of housefly. The garlic extracts can potentially be used to manage housefly. However, further investigations on the larval and adult mortality are needed.  相似文献   

14.
15.
Thirty-five nematode species belonging to 19 genera were extracted from 432 soil and root samples collected in 19 districts in six provinces in the North Central Coast, Central Highlands and Phu Quoc Island. Based on our study, the predominant nematode species associated with black pepper plants in Vietnam is Meloidogyne incognita: almost every soil and root sample examined during our study was infected with this root-knot nematode species. No difference in frequency of occurrence of M. incognita among the three agro-ecological regions surveyed was observed. However, the root population density of M. incognita in black pepper plants was on average about five times higher in the North Central Coast and Central Highlands than in Phu Quoc Island. Large differences in root population density of M. incognita on black pepper plants were observed in different districts within the same agro-ecological region. Black pepper roots infected with M. incognita showed the same type of galls as described in the literature. The percentage of root galling averaged about 40% in all the three agro-ecological regions. The percentage of black pepper plants with yellow leaves was on average about 20–25% in the North Central Coast and Central Highlands, which was somewhat higher compared to Phu Quoc Island (16.9%). Large differences in percentage of black pepper plants with yellow leaves were observed in different districts within the same agro-ecological region. The same type of yellow leaves as described in the literature for black pepper plants infected with Meloidogyne species was observed in our study. In general, a positive relationship between the soil and root population densities of M. incognita on black pepper plants and percentage of plants with yellow leaves was observed. However, in one district (Quang Tri) a relatively low nematode population density was associated with a high percentage of plants with yellow leaves. Five nematode species were recorded for the first time on black pepper plants in Vietnam. Our study reconfirms previous reports that Radopholus similis does not occur in Vietnam.  相似文献   

16.
We investigated the radiobiological effects of the radon daughter bismuth-212 (212Bi) in Chinese hamster ovary (CHO) K1 cells and in xrs-5 cells, which are X-ray sensitive and deficient in the ability to rejoin DNA double-strand breaks. The cells were exposed to 250 kVp X-rays or to 212Bi chelated to diethylene triamine pentaacetic acid (DTPA); chelation of 212Bi to DTPA prevented its attachment to or entry into the cells. Cytotoxic, clastogenic, and mutagenic responses of the cells were measured and RBEs (D10, 2 chromatid aberrations/cell and 10 induced 6-thioguanine-resistant mutants) were calculated to be 3.8, 3.5, and 3.9, respectively for K1, and 1.4, 0.8, and 5.1, respectively, for xrs-5. With the exception of the RBE of less than 1 for alpha-induced aberrations in xrs-5, the results are consistent with the following conclusions: (1) alpha-particles are in general more effective cytotoxic, clastogenic and mutagenic agents than X-rays; (2) the primary lethal and clastogenic lesion induced by both X-rays and alpha-particles is probably a DNA double-strand break; (3) DNA double-strand breaks induced by alpha-radiation are less well repaired than those induced by X-rays, although a portion of alpha-induced damage is repairable; and (4) deficiencies in rejoining DNA double-strand breaks affect the clastogenic and cytotoxic effects of X-rays and alpha-radiation, not their mutagenic effects. The RBE of 0.8 for aberration induction in xrs-5 cells could reflect a deficiency in the ability of these cells to convert alpha-induced damage to chromosome aberrations. Alternatively, the RBE of less than 1 might reflect an unusual sensitivity of xrs-5 cells to alpha-induced G2 delays.  相似文献   

17.
Growth and aflatoxin production byAspergillus flavus (MAM-268 C17, TNS=98) on autoclaved coconut, black pepper, crushed red pepper, red pepper powder were studied. Coconut were found to be a better substrate for fungal growth, as well as aflatoxin production. Red pepper powder could be considered as a poor substrate for fungal growth. The amount of aflatoxin found in crushed red pepper under laboratory conditions is much less compared with coconut, black pepper and red pepper powder.  相似文献   

18.
Ahmed S  Othman OE 《Mutation research》2003,541(1-2):115-121
Fasinex (triclabendazole) has been reported to be an active fasciolocidal agent used in humans and in farm animals. The clastogenic effects of fasinex were tested in lymphocyte cultures of the river buffalo at three final concentrations: 25, 50 and 100 microg/ml. Chromosomal aberrations, sister chromatid exchanges and micronucleus formation are the three cytogenetic parameters used in this study.The results demonstrated that the number of cells with different types of chromosomal aberrations, including chromatid breaks and gaps, isochromatid breaks and gaps and polyploidy, was increased significantly in cultures treated with different doses of fasinex compared to the control. This increase was dose-dependent where there was a positive correlation between increased drug concentration and induction of chromosomal aberrations.The frequency of sister chromatid exchanges and the formation of micronuclei in all lymphocyte cultures treated with different doses of fasinex were increased significantly compared to the control; these increases were also dose-dependent.In conclusion, the three cytogenetic parameters used to evaluate the effect of fasinex revealed that the drug has a strong clastogenic effect on river buffalo lymphocytes in vitro.  相似文献   

19.
Bacterial antagonists of Phytophthora capsici were isolated from underground shoot portions of rooted cuttings of black pepper. Initially isolates were screened by dual culture on potato dextrose agar and carrot agar. Further, a screening was done on black pepper shoots for supression of lesion caused by the pathogen. Most of the antagonists showed varying levels of antagonism in the dual culture and the shoot assay. Isolate PN-026, showing the highest suppression of lesion development in the shoot assay was found to be the most efficient antagonist in reducing Phytophthora capsici induced nursery wilt of black pepper. This screening involving the host, pathogen, and the antagonist, performed on black pepper shoot (the planting material for this vegetatively propagated crop), could be used as a rapid and reliable method for the isolation of efficient bacterial antagonists of P. capsici.  相似文献   

20.
It was supposed earlier that achromatic gaps could be used as markers of mutagenic effect of environmental pollution, especially under weaker clastogenic influences. The frequencies of true chromosome aberrations and those of chromatid gaps were estimated in house mice and common voles from Uralian localities with various mutagenic potential of environment. Gaps and breaks were distinguished according to the CBIS system. In several localities, rodents displayed highly significant increase of the rates of cells with chromosome aberrations and with gaps as compared to the baseline values; only in the common vole, the P level for the gap increase was 0.056. The mean gap rate was correlated significantly with that of chromosome aberrations, not only with chromatid breaks, but with the aberrations of other types, too. This parameter appears not to be more sensitive indicator of environmental mutagens than true chromosome mutations, when mutagenic impact is not very powerful, as it was in the localities investigated. The house mouse can be recommended as an effective test species for ecogenetic monitoring.  相似文献   

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