Pure Air Control Services and the Environmental Diagnostics Laboratory are pleased to introduce "Under the Scope", a new section of the IEQ REVIEW. There are over 100,000 species of fungi. Many fungi are good and useful (edible mushrooms would be an example of these) while some cause problems (some fungi can injure plants and humans). Every week the IEQ Review will describe a specific microorganism, its morphological origin and potential health effects.  If you would like to know about a specific organism and/or would like it published in The IEQ Review please email Dr. Rajiv Sahay with the Environmental Diagnostics Laboratory (EDL) at Pure Air Control Services laboratory@pureaircontrols.com

This week we will cover ...   
 
Aspergillus Niger grows on Czapek dox agar (CDA) and MEA, colonies consist of a compact white or yellow basal felt covered by a dense layer of dark-brown to black conidial heads.  Commonly found on textiles, in soils, grains, fruits, and vegetables.  Conidial heads are large (up to 3 mm x 15-20 um in diameter), globose, dark brown, becoming radiate and tending to split into several loose columns with age. Conidiophores are smooth-walled, hyaline or turning dark towards the vesicle. Conidial heads are biseriate with the phialides borne on brown, often septate metulae. Conidia are globose to subglobose (3.5-5.0 um in diameter), dark brown to black and rough-walled.
 
Clinical significance
Aspergillus niger is one of the most common and easily identifiable species of the genus Aspergillus, with its white to yellow mat later bearing black conidia. This is the third most common species associated with invasive pulmonary aspergillosis. It is also often a causative agent of aspergilloma and is the most frequently encountered agent of otomycosis.
 

Aspergillus Niger
 
For more information on microorganisms, IEQ investigations or laboratory samples and protocols please contact:
Dr. Rajiv Sahay
Pure Air Control Services
1-800-422-7873 ext 304
laboratory@pureaircontrols.com