当前位置： SCI文献检索 > LETTERS IN APPLIED MICROBIOLOGY期刊下所有文献 > Molasses supplementation promotes conidiation but suppresses aflatoxin production by small sclerotial Aspergillus flavus.

Molasses supplementation promotes conidiation but suppresses aflatoxin production by small sclerotial Aspergillus flavus.

Abstract：

AIMS:To find a supplemental ingredient that can be added to routinely used growth media to increase conidial production and decrease aflatoxin biosynthesis in small sclerotial (S strain) isolates of Aspergillus flavus. METHODS AND RESULTS:Molasses was added to three commonly used culture media: coconut agar (CAM), potato dextrose agar (PDA), and vegetable juice agar (V8) and production of conidia, sclerotia, and aflatoxins by A. flavus isolate CA43 was determined. The effect of nitrogen sources in molasses medium (MM) on production of conidia, sclerotia and aflatoxins was examined. Water activity and medium pH were also measured. Conidia harvested from agar plates were counted using a haemocytometer. Sclerotia were weighed after drying at 45 degrees C for 5 days. Aflatoxins B(1) and B(2) were quantified by high-performance liquid chromatography. Addition of molasses to the media did not change water activity or the pH significantly. Supplementing CAM and PDA with molasses increased conidial production and decreased aflatoxins. Two-fold increased yield of conidia was found on MM, which, like V8, did not support aflatoxin production. Adding ammonium to MM significantly increased the production of sclerotia and aflatoxins, but slightly decreased conidial production. Adding urea to MM significantly increased the production of conidia, sclerotia and aflatoxins. CONCLUSIONS:Molasses stimulated conidial production and inhibited aflatoxin production. Its effect on sclerotial production was medium-dependent. Water activity and medium pH were not related to changes in conidial, sclerotial or aflatoxin production. Medium containing molasses alone or molasses plus V8 juice were ideal for conidial production by S strain A. flavus. SIGNIFICANCE AND IMPACT OF THE STUDY:Insight into molecular events associated with the utilization of molasses may help to elucidate the mechanism(s) that decreases aflatoxin biosynthesis. Targeting genetic parameters in S strain A. flavus isolates may reduce aflatoxin contamination of crops by reducing the survival and toxigenicity of these strains.

journal_name

Lett Appl Microbiol

journal_title

Letters in applied microbiology

authors

Chang PK,Hua SS

doi

10.1111/j.1472-765X.2006.02056.x

subject

Has Abstract

pub_date

2007-02-01 00:00:00

pages

131-7

issue

eissn

0266-8254

issn

1472-765X

pii

LAM2056

journal_volume

pub_type

杂志文章

在线工具

Molasses supplementation promotes conidiation but suppresses aflatoxin production by small sclerotial Aspergillus flavus.