Molecular Divergence and Identification of Aspergillus Species in Dry Fishes of Gujarat, India

Abstract

The fungal infestations have become significant cause for the quality and economic loss. They often cause infections to the handlers and consumers. Some of the fungal species are potent allergens, mycotoxin producers and can even cause superficial and pulmonary infection. Reports of previous studies are restricted to genus level due to overlapping of morphological characters. So, the present study was carried out to identify the predominant fungal species prevalent in fishes of west coast region by molecular technique. Totally, 24 sundried fishes were collected from the Veraval region of Gujarat and analyzed for the presence of fungal species. Randomly collected fungal strain was initially indentified based on morphological characters and polymerase chain reaction was carried out for the amplification of 18S rDNA gene. The amplicon was sequenced and analyzed using BLAST. The sequence analysis revealed that Aspergillus flavus, A. nidulans, A. oryzae, A. sydowii, A. rugulosa, A. niger, A. foetidus, Lichtheimia ramosa and Curvularia lunata were present in dried fish. The phylogenetic tree was constructed based on DNA sequence dissimilarity and revealed that two clades were formed among the fungal species with one clade belonging to A. nidulans, A. rugulosa and A. sydowii and the other to A. flavus and A. oryzae. Therefore, it is concluded that, in west coast region A. flavus is a dominant species observed in dry fish which is potent aflatoxin producers and highly carcinogenic in nature. So, handlers need stringent hygienic practices with suitable processing and packaging technique to control the fungal contamination.