Vol. 9, Special Issue 10, Part R (2025)

Composition and diversity of airborne microbes vary significantly across different urban environments, influencing human health. This study was aimed to analyse the air microbiota in different environments (laboratory, garbage van, traffic congested road, hospital) which could play role on air quality and public health.

Settle-plates with Trypticase soy agar (TSA) and Potato Dextrose agar (PDA) were used for sampling air (10 min and 1 hr). Each environment harboured distinct microbial communities (both bacteria and fungi), influenced by human activity, environmental and sanitary conditions. 11 strains (SJ-1, SJ-3-7, SJ-9-10, SJ-13, SJ-15-16) were characterized based on morphology. Colonies were white, cream and yellow coloured, with mucoid or chalky consistency, and irregular or smooth margins. Fungus with white mycelia were also obtained. CFU/m³ was estimated to be 0.0424, 0.328, 0.167 & 0.099 (10 min). All the bacterial strains were gram positive, with majority coccus and catalase positive (except SJ-3, 10). SJ-9, 15 and 16 were identified as Staphylococcus sp. Our tests also suggested that SJ-6, 7 belong to Bacillus subtilis or Bacillus cereus, although further tests were warranted. SJ-3, 10 were gram positive cocci, non-motile, catalase and oxidase negative, suggesting presence of Streptococcus sp., which is a common bacterial species in any air sample. Antibiotic susceptibility tests using Kanamycin revealed MIC 32 μg/ml for SJ-1, 7, 9, while it was above 256 μg/ml for all others. Thus, the present study sheds light on air quality in various indoor and outdoor environments, which need to be kept under check to prevent any health issues.