Search PubMed⌕ Search

Biomedical subjects

A Ciegler

Publications and source records attributed to A Ciegler.

At least 19 recordsLinked to original sources
PubMed1985

Effect of phytate on aflatoxin formation by Aspergillus parasiticus grown on different grains.

Aflatoxin production by Aspergillus parasiticus on corn, soybean, and cottonseed in the absence or presence of added sodium phytate was examined. No variation in aflatoxin concentrations was found in raw, chemically sterilized, or autoclaved soybeans whereas a five-fold reduction in total aflatoxins was found in cottonseed after addition of 330 micrograms sodium phytate to 10 g of autoclaved material. However, phytate did not affect aflatoxin production on non-sterile cottonseeds, although in corn a slight inhibition was found. Extraction of raw soybeans with hexane allowed production of 20-fold more aflatoxins, but levels were still lower than those found on rice or corn. Part of this relative inhibition in soybeans may arise from a heat-unstable, polar solvent-soluble, dialyzable factor present in soybeans. Our results support the conclusion that phytate is not the factor in soy responsible for its relative resistance to aflatoxin formation.

Aflatoxins↗
PubMed1985

The effect of drying method and storage time on citrinin activity in corn.

Sterilized whole corn was inoculated with a Penicillium spp.,3 a citrinin-producing fungus, and incubated at room temperature for 8 weeks. The corn was then blended and divided into two parts, which were dried either in air at room temperature (ADC) or in a forced draft oven at 60 C for 24 hr (ODC). Each batch of corn was ground and stored in plastic containers. The corn was fed to broiler chicks prior to and after 3, 6, 9, and 12 months of storage at 4 C. The inoculated corn was fed undiluted or blended with noninoculated corn to give mixtures containing one-third and two-thirds of inoculated corn. Noninoculated corn, inoculated corn, and blends of the two were fed to chicks for 5 hr as the only feed. Feed consumption, water intake, and excretion were measured at the end of the test. The citrinin contents of the ADC at 3, 6, 9, and 12 mo were 824, 599, 667, and 590 ppm and were 928, 541, 781, and 490 ppm for the ODC at the same periods. Water consumption and water excretion increased as the amount of citrinin intake increased. Neither drying method nor length of storage affected the citrinin activity in the corn. The citrinin in ODC was neither bound nor converted to a derivative that was unextractable.

Animal Feed↗
PubMed1985

Effect of heat drying of corn on the extraction of citrinin.

Experiments were conducted to determine if drying citrinin-contaminated corn at varying temperatures and times either bound citrinin or converted it to a derivative that could not be extracted from the grain. Sterilized whole corn was inoculated with spores of a Penicillium spp. that produces citrinin and was incubated for 8 weeks. Following incubation, the corn was mixed and divided into three portions. In Experiment 1, one portion was dried at room temperature and the other portions were dried at 65 C for either 40 or 72 hr. In Experiment 2, one portion was air-dried and the other portions were dried at 60 C for 24 hr or 100 C for 3 hr. The corn was then ground to a texture suitable for feeding to chicks. Analysis of the corn indicated that temperature or length of drying time had no adverse effects on the extraction of citrinin from the corn. The citrinin was not rendered unextractable by either being bound because of heating or by being converted to a derivative. When fed to chicks for 5 hr, water consumption and urine excretion data indicated that there was no loss of citrinin activity because of method of drying.

Animal Feed↗
PubMed1984

Effect of phytate on aflatoxin formation by Aspergillus parasiticus and Aspergillus flavus in synthetic media.

The effect of phytate on the production of aflatoxins by Aspergillus parasiticus and Aspergillus flavus grown on synthetic media was examined. In the absence of pH control (initial pH 4.5-6.5) for A. parasiticus, phytate (14.3 mM) caused a six-fold decrease in aflatoxins in the medium and a ten-fold decrease in those retained by the mycelia. When the initial pH of the medium was adjusted to 4.5 no effect on aflatoxin production was observed. With A. flavus or A. parasiticus grown on media with a higher initial pH value (6 to 7), the presence of phytate in the media caused an increase in aflatoxin production. These results are inconsistent with previous studies which indicated that phytate depresses aflatoxin production by rendering zinc, a necessary co-factor for aflatoxin biosynthesis, unavailable to the mold.

Aflatoxins↗
PubMed1984

Naphtho-gamma-pyrone production by Aspergillus niger isolated from stored cottonseed.

Aspergillus niger was found to be the predominant fungal contaminant of stored cottonseed. Seven strains were isolated and grown on rice. The hexane-insoluble material from methylene chloride extracts of 2-week-old cultures contained components toxic to mice. Based on high-pressure thin-layer and liquid chromatographic analyses, the major components in the mixture were eight different naphtho-gamma-pyrones. Of these, the hydrated dimeric naphthopyrones aurasperones B and C occurred in higher yield than aurasperones A, iso-A, and D and the monomeric naphthopyrones flavasperone and rubrofusarin, all of which were present in the mixture. In addition, fonsecin monomethyl ether was isolated. This metabolite may be a precursor in the biosynthesis of the hydrated aurasperones; it has not been identified previously as a metabolite of A. niger. The relative amounts of the different naphthopyrones were dependent on both the growth substrate and the fungal isolate.

Aspergillus niger↗
PubMed1983

Production of aflatoxins on soybean and cottonseed meals.

p6e production of aflatoxins by Aspergillus flavus SRRC-1000 growing on soybean (Forrest) and glandless cottonseed (Deltapine 16) meals was examined with respect to effects of zinc and phytate. Aflatoxins were not produced on unautoclaved soybean meal. Addition of zinc (as zinc sulfate) to autoclaved meal inhibited aflatoxin production and supplementation with sodium phytate relieved this inhibition. Addition of sodium phytate alone promoted production. When cottonseed meal was treated to release native phytate into the meal from phytate-sequestering globoids, aflatoxin production increased. However, the largest production on cottonseed meal occurred upon dialysis of the meal without releasing phytate, implying removal of a small molecular weight inhibitor.

Aflatoxins↗
PubMed1983

Preliminary study of mycoflora and mycotoxins in grain dust from New Orleans area grain elevators.

Dust particles arising from disintegration of grain during handling and shipping may be inhaled by exposed barge and elevator workers. Since the normal grain mycoflora usually contain mycotoxin-producing fungi, these toxins could be natural contaminants of grain dust. Known mycoflora of commercial grain include species of Penicillium, Aspergillus, and Fusarium-fungi that may produce ochratoxins, aflatoxins and zearalenone. A procedure was developed to extract simultaneously these toxins from grain dust. Initial extraction with methylene chloride and water was followed by specific cleanup procedures for each toxin and then by thin layer chromatographic quantitation. In 50-g samples the lowest level of detection for zearalenone was 50 ng of zearalenone/g of dust, for ochratoxin, 10 ng/g and for aflatoxin, 5 ng/g. Dust samples were collected at various locations in two grain elevators and their associated transfer facilities in the New Orleans area. Large amounts of dust that had settled upon floors, machinery and ledges were tested, as well as that which had been collected by dust control systems. Samples were analyzed for aflatoxins, ochratoxin A, and zearalenone. None of the 15 samples contained any detectable amount of aflatoxins or ochratoxin A, but 10 of the 15 samples contained zearalenone at levels from 25 to 100 ng/g.

Dust↗
PubMed1982

The inability of Fusarium species extracts to induce dieback in pine.

Cultures of F. moniliforme var. subglutinans, F. moniliforme, F. lateritium, F. equiseti, F. semitectum and F. solani from pine and F. moniliforme and F. graminearum from southern U.S. corn were grown on rice and corn, extracted, and checked for toxicity in mice, chicken embryos, and pine seedlings, and for mutagenicity by the Ames test. While extracts from both fungal groups contained toxins, none of the extracts induced dieback in pine seedlings. Almost all of the cultures isolated from corn in contrast to those from pine, were mutagenic. Thin-layer chromatography did not detect T-2 toxin, moniliformin, or vomitoxin, indicating that these toxins do not elicit dieback symptoms in pine.

Animals↗
PubMed1982

Mutagenicity and toxicity of aflatoxin precursors.

The Salmonella/microsome test and the chick embryo test were used to determine the mutagenicity and toxicity of five aflatoxin B1 precursors. A definite pattern emerges: the nearer the B1 an intermediate appears in the biosynthetic pathway, the more potent is its mutagenicity and toxicity.

Aflatoxin B1↗
PubMed1982

Secalonic acid D toxicity in rat lung.

Toxicity of the mycotoxin secalonic D (SAD) was examined histopathologically in rats. Dose response was studied by intragastric and intratracheal instillation, and SAD was given in suspension in Krebs-Ringer phosphate solution at doses well below the reported LD50 values for both rats and mice. A full autopsy was performed on rats sacrificed 1--69 d after instillation. Responses differed markedly depending on the route of administration. Histopathological lesions were observed only in the lungs of rats receiving SAD intratracheally. At 24 h after treatment, the lungs of affected animals showed an acute polymorphonuclear reaction in the distal airways and adjacent alveoli and there was necrosis of airway epithelium. The latter resulted in the development of typical lesions of bronchiolitis obliterans. The initial acute inflammatory response in the peripheral lung became granulomatous at 3 d and the granulomas contained numerous foreign body type giant cells. Between 3 and 7 d the granulomas and bronchiolitis obliterans increased in severity; thereafter they tended to resolve. On termination of the experiment at 69 d there were a few small residual granulomas; however, no significant irreversible pulmonary injury was observed.

Animals↗
PubMed1982

Secalonic acid D: natural contaminant of corn dust.

The mycotoxin secalonic acid D was detected for the first time as a natural contaminant of corn dust obtained from grain storage elevators. Secalonic acid D amounts ranged from 0.3 to 4.5 ppm (0.3 to 4.5 micrograms/g), as determined by reversed-phase high-performance liquid chromatography.

Dust↗
PubMed1981

Role of lactone ring of aflatoxin B1 in toxicity and mutagenicity.

Cleavage of the lactone ring of aflatoxin B1 results in a nonfluorescent compound that has greatly reduced biological activity. Mutagenicity, as measured by the Ames test, is reduced 450-fold compared to that of B1, and toxicity, as measured by the chick embryo test, is reduced 18-fold.

Aflatoxin B1↗
PubMed1980

Evaluation of bone strength during aflatoxicosis and ochratoxicosis.

Young chickens were fed graded levels of aflatoxin (0, 0.625, 1.25, 2.5, 5.0, and 10.0 mug/g of diet) or ochratoxin (0, 0.5, 1.0, 2.0, 4.0, and 8.0 mug/g of diet), and the breaking strength, displacement before failure, and diameter of their tibias were determined. Breaking strength was decreased at growth inhibitory levels of aflatoxin (2.5 mug/g) and ochratoxin (2 mug/g), whereas a reduction in diameter required higher levels (5.0 and 4.0 mug/g, respectively). Bones from birds with ochratoxicosis selected to have diameters equal to control bones had lower breaking strength. In an attempt to negate mathematically the effect of decreased diameter and bias in any selection process, stress at time of failure of the bones was calculated and found to be decreased by feeding aflatoxin but not ochratoxin. Total displacement of bones before breaking was increased significantly (P < 0.05) by both toxins at the highest levels administered, but this increase was primarily the result of an increase in displacement from the start of failure to complete failure. Increased displacement associated with both toxicoses was equal in bones selected to be of equal diameter or in bones from the same treatment but of different diameters. However, calculation of modulus of elasticity which is corrected for diameter revealed aflatoxin had no effect whereas ochratoxin tripled the effect. These data indicate that the material properties of bones can be altered during mycotoxicoses and suggest yet another way in which mycotoxins are detrimental to animal health.

Aflatoxins↗
PubMed1980

Evaluation of penicillic acid for toxicity in broiler chickens.

Penicillic acid is a mycotoxin produced by various fungi. It may occur in high concentrations in corn and can also be produced concomitantly with other mycotoxins in poultry feed. This mycotoxin was evaluated for its toxicity in broiler chickens by feeding graded concentrations (0, 100, 200, and 400 microgram/g of diet) to 4 groups of 10 birds per treatment. No significant (P greater than .05) effects were measured on growth rate, feed conversion, relative size of pancreas, spleen, liver, heart, bursa, or kidney or on hemoglobin, packed cell volume, liver lipid, plasma protein, or glucose. The only significant effects were a slight reduction in the size of the proventriculus and gizzard at dose levels of 200 and 400 microgram/g. Neither the salt nor lactone forms of penicillic acid had any detectable effect. The acute oral LD50 for the sodium salt form was 92 +/- 9 mg/kg. These data suggest that penicillic acid by itself has little toxicity (less than 1% of that of aflatoxin) in chickens.

Animals↗