Quantification using a HPLC-FLD-based Detector and Molecular Identification of Ochratoxin-A Producing Aspergillus Species Isolated from Stored Grain Samples.

Abstract

Aim: Quantification using an HPLC-FLD based detector and Molecular identification of Ochratoxin-A producing Aspergillus Species isolated from stored grain samples.

Background: Fungi are cosmopolitan in origin and are known to grow in any suitable substratum. In the present investigation, Aspergillus species isolated from stored grain samples were analyzed for ochratoxin-A production.

Objective: The objective of this study is the quantification of Ochratoxin and identification of ochratoxigenic fungi.

Methods: A total of n=34 black Aspergilli and n=1 Ochre Aspergilli were isolated from grain samples of Bihar, India and it was tested for OTA production. The limit of detection (LOD) is found to be 0.33 μg/kg and the limit of quantification (LOQ) is found to be 1 μg/kg for OTA in HPLC-FLD.

Results: In the present study, out of all the fungal isolates, only TiB fungal isolate was able to produce the ochratoxin-A above the level of LOQ. The positive isolate TiB obtained from stored sesame seed samples was able to produce 25.54 μg/kg of OTA. ITS sequence analysis of TiB isolate was able to match 100% with Aspergillus welwitschiae and Aspergillus foetidus.

Conclusion: This is the initial report of ochratoxigenic Aspergillus fungal isolate isolated from stored sesame seed samples of flood-prone areas of Bihar, India.