Enumeration and characterization of airborne microbial communities in an outdoor environment of the city of Taj, India

Abstract

In the present investigation, the microbiological characteristics of the air in the outdoor environment of the city of Taj, i.e., Agra (India) was assessed by determining the concentration and composition of bacteria and fungi using culture technique. The bacterial isolates having the highest prevalence (100%) throughout the year were selected and identified based on morphological, physiological, and biochemical characteristics. The mean concentration of bacteria in PM10 and PM2.5 was 405.1 CFUm-3 and 364.9 CFUm-3, respectively, while the mean concentration of fungi in PM10 and PM2.5 was 136.5 CFUm-3 and 20.3 CFUm-3, respectively. A new technique of BD (Becton Dickinson)BBL Crystal Mind Auto reader was used. The bacteria were identified as Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Micrococcus luteus, Chromobacterium violaceum, Bacillus cereus, Brevibacillus brevis, Enterobacter aerogenes, Pseudomonas aeruginosa, Acinetobacter beijerenckii. Fifteen fungal isolates were identified comprising of Fusarium, Aspergillus, Epicoccum, Penicillium, Cladosporium, Trichoderma. Alternaria, Mucor, Rhizopus, Geotrichum, Helminthosporium, Absidia, Cephalosporium, Botrytis, and Neurospora. Aspergillus and Penicillium have the maximum percentage occurrence of 98% and 95%, respectively. Botrytis recorded a minimum percentage of 22%, followed by Neurospora 20%. The concentration of bacteria and fungi depend upon the meteorological conditions.