T AXONOMIC CHARACTERISATION OF ACTINOBACTERIA ISOLATED FROM THE ATMOSPHERE SURROUNDING CHAMOMILE PLANTS

Abstract

The aim of this study was to characterize the actinobacteria isolated from the atmosphere surrounding chamomile plants (from the beginning of cultivation until harvesting) in El-Fayoum Governorate, Egypt. Air samples were collected between January and March 2003. A total of 311 actinobacteria isolates were obtained: Streptomyces anulatus (n=143), S. albus (n=52), S. californicus (n=23), Streptomyces spp. (n=11), Micrococcus roseus (n=27), M. luteus (n=17), Micrococcus spp. (n=6), Rhodococcus spp. (n=10), Arthrobacter globiformis (n=4), Arthrobacter spp. (n=4), Microbacterium spp. (n=5), Cellulomonas spp. (n=5), and Nocardia spp. (n=4). The mean count (colony forming unit/plate/h) of actinobacteria increased slightly from the beginning of the cultivation period (November) to beginning of January. A significant increase in bacterial count was observed during the end of January and the beginning of March (harvesting period), followed by a drastic decrease during the end of March (late harvesting). The biochemical and morphological characteristics of these bacteria are described. It is concluded that farmers that are exposed to large concentrations of grain dust and associated microorganisms during the harvesting period are at an increased risk of developing respiratory disorders such as allergic alveolitis, asthma, chronic bronchitis, and organic dust toxic syndrome.