Related Experiment Video
Updated: Aug 15, 2026

Methods for Characterizing the Co-development of Biofilm and Habitat Heterogeneity
Published on: March 11, 2015
The occurrence and persistence of mixed biofilms in automobile air conditioning systems
R B Simmons1, L J Rose, S A Crow
1Environmental Research Center, Dept of Biology, PO Box 4010, Georgia State University, Atlanta, GA 30302-4010, USA.
Abstract:
Twelve automobile air conditioner systems from six manufacturers and three countries, selected mostly because of complaints of unpleasant odors in the passenger compartment, were examined for microbial growth by direct microscopy and enrichment culture. Mixed populations of fungi and bacteria (with occasional protozoa) were observed in biofilms in at least some of the components from all used units. The aluminum heat exchanger fins from ten evaporators demonstrated bacterial biofilms that yielded Methylobacterium mesophilicum. Penicillium viridicatum colonized components from four units. These bacteria and fungi were recoverable repeatedly from these units during 'dry' storage of up to 27 months. This report associates a bacterial-fungal community with disagreeable air quality in some automobiles.
Related Concept Videos
Surface Membrane Barriers
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...
Biofilms
Microbial Mats
Bioreactor Controls-I
Bioreactor Controls-II
Microbiota of the Respiratory Tract

