Incidence and significance of black aspergilli in agricultural commodities: a review, with a key to all species accepted to-date

Abstract

Black aspergilli ( Aspergillus species of Section Nigri ) present dark colonies, often black, and uniseriate or biseriate conidial heads. Currently 26 species and one variety are accepted within this section. They have been isolated from a wide variety of food worldwide and are considered as common causes of food spoilage and biodeterioration of other materials. They are commonly present in cereals and vineyards and have the ability to cause Aspergillus rot of black berry. Some species of this section, like A. niger and A. awamori , are a common source of extracellular enzymes such as amylases and lipases, and organic acids, such as citric and gluconic acid, used as additives in food processing and are used for biotechnological purposes. These products hold the GRAS (Generally Recognised as Safe) status. Other species are able to produce ochratoxins (OTA) and fuminisins. This review briefly shedlighted on the taxonomy of this important group of Aspergillus along with the species incidence, mycotoxin production in agricultural commodities as well as their significance as plant pathogens. A provisional key for identification (based on phenotypic characteristics) is provided for all described species to-date.