Evaluation of Fungal Flora and Aflotoxins from the Ground Nuts Collected from Various Regions of Warangal District

Abstract

Aims: The aim of the current study is to screen about twenty three ground nut samples for the identification and detection of mycotoxin-producing fungi and type of mycotoxin. Study Design: The present investigation was designed to identify the type of mycotoxin in the ground nut samples collected from various regions of Warangal district of Telangana State, India. Place and Duration of Study: Mahabubabad, Nekkonda, Thorrur, Palakurty, Jangon etc., of Warangal district, 2 years; from July 2014 to July 2016. Methodology: The study includes: analysis of moisture content M.C. mycological analysis, isolation of sample-borne mycoflora, isolation of sample surface mycoflora, standard dilution plate, identification of the fungal genera, determination of potential toxigenic fungi using DRBC test, aflatoxin extraction and analysis by ELISA. Results: The M.C. of samples collected during wet season from Mahabubabad, Nekkonda, Thorrur, Palakurty, Jangon of different storage systems ranged between 13.1 – 17.0%, 17.7%, 12.8%, 15.4%, 14.1%, 9.0%, 12.5%, 10.6%, respectively. The freshly harvested ground samples showed highest M.C. percentage with 36.6%. Using Czapek Dox Agar (CDA) media we have isolated six fungal genera containing fourteen species from sterilized and unsterilized samples. Isolated genera were Aspergillus spp. Cladospoium sp., Fusarium sp., Rhizopus stolonifer, Penicillium spp. and yeasts and the fourteen species were isolated from the surface of the collected samples. The commonly observed species were R. stolonifer, A. candidus, A. flavus, A. tamarii,         A. wentii, A. ochraceus, A. niger, P. fellutanum, P. citrinum, A. ochraceus, Yeast, F. equiseti,            P. aethiopicum. The identification and the total Colony Forming Units (CFU) of isolated fungi were performed using standard plate technique. The total enumerated CFU of isolated fungi from the 23 collections was (114×103). High fungal contamination was observed in the sample kadiri-2 followed by Jyoti and JM-3. Detection of toxogenic fungi using DRBC media tested positive for several fungal species. Aflotoxin analysis using ELISA showed that Kadiri-2 (MK-374), Jyoti and JM-3 produced 8.6, 6.4, 7.0, ppb of aflatoxin content. Conclusion: Using Czapek Dox Agar (CDA) six fungal genera comprising fourteen fungal species were isolated from sterilized and unsterilized samples. Identification and estimation of the total Colony Forming Units (CFU) of fungi was carried out using standard plate technique. The total enumeration of isolated fungi from the 23 collections was (114×103) CFU. Aflotoxin analysis using ELISA showed that the concentrations of aflatoxin in the samples are low and below permitted limits.