Production of ochratoxin a by aspergillus ochraceus NRRL-3174 before and after exposures to /sup 60/Co irradiation

Journal Article · Mon Mar 01 04:00:00 EST 1976 · Appl. Environ. Microbiol.; (United States)

OSTI ID:5370769

Applegate, K L; Chipley, J R

Spores from the toxigenic organism Aspergillus ochraceus NRRL-3174 were exposed to specific levels of gamma irradiation and then allowed to germinate on selected media. Increases in ochratoxin A production by irradiated, compared to non-irradiated, spores were observed after inoculation of spores onto a cracked red wheat or into a synthetic liquid medium. Variations in daily ochratoxin production were also observed for control and irradiated spore-derived cultures developing on both media, with maximum toxin production varying from 7 to 11 days of incubation. The most notable increases in ochratoxin A production occurred from cultures developing from spores having been irradiated with 10, 25, or 50 krad. Exposures to 400 or 600 krad resulted in complete inhibition of spore germination and, consequently, no ochratoxin production. Of the two substrates used, wheat and synthetic, the quantities of ochratoxin A produced were significantly lower in the synthetic media than on the natural substrate. Higher and more rapid toxin production occurred from spores having been irradiated with 10, 25, 50, and 100 krad than occurred from the non-irradiated control spores when grown on synthetic media. Cultures derived from spores having been exposed to 10, 25, and 50 krad produced significantly higher levels of ochratoxin A after 8 days of incubation on natural substrate than did the controls. Analysis of variance revealed that substrate, length of incubation, as well as irradiation levels all affected the time required to produce maximum levels of ochratoxin A.

• Research Organization: Ohio State Univ., Columbus
• OSTI ID: 5370769
• Journal Information: Appl. Environ. Microbiol.; (United States), Journal Name: Appl. Environ. Microbiol.; (United States) Vol. 31:3; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

560131* -- Radiation Effects on Microorganisms-- Basic Studies-- (-1987)
560132 -- Radiation Effects on Microorganisms-- Food Preservation-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANTIGENS
ASPERGILLUS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOMASS
COBALT 60
COBALT ISOTOPES
CULTURE MEDIA
DOSE-RESPONSE RELATIONSHIPS
ELECTROMAGNETIC RADIATION
ENERGY SOURCES
FUNGI
GAMMA RADIATION
INCUBATION
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
IRRADIATION
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
PLANTS
PRODUCTION
RADIATION EFFECTS
RADIATIONS
RADIOISOTOPES
RADIOSENSITIVITY EFFECTS
RENEWABLE ENERGY SOURCES
SPORES
TOXIC MATERIALS
TOXINS
YEARS LIVING RADIOISOTOPES