Coating with Odourless Microorganisms to Improve Indoor Air Quality

Air-conditioning systems are indispensable for human daily life. Clean air is recognised as an integral component in human health and well-being while offensively smelling or polluted air severely spoils a pleasant environment. However, microbial activity and offensive odours in indoor air continue to be an issue in indoor environments such as in automobiles or airplanes.

Although various types of fragrances are commercially available for removing offensive odours, they do not fundamentally remove the moulds and bacteria proliferating on the evaporator core but merely dilute the unpleasant odour temporarily. Also, the antibacterial agents that are commercially available at present are not developed to specifically act on particular moulds or bacteria proliferating on the evaporator core.

To address this, an eco-friendly air purification technology was developed using a biofilm coating containing odourless microorganisms to improve indoor air quality, in particular, in air-conditioning systems such as in automobiles.

Various species and strains of odourless microorganisms were screened and confirmed that when a biofilm is formed using a combination of microorganisms from the Methylobacterium species, the growth of offensive odour-causing microorganisms can be prevented, thus reducing offensive odours and increasing indoor air quality.

Biofilm works as biofiltration that degrades volatile organic compounds (VOCs) using living materials (odourless bacteria). The odourless bacteria decompose VOCs to low odour or odourless gases. With usage of the air-conditioning systems, there will be increase in accumulation of odour-generating bacteria. This bacteria complex of both odourless and odour-generating bacteria will decompose VOCs and generate odourless or odour gases according to their own metabolisms. The odourless bacteria biofilm is designed specifically to moderate generation of odourous gases over a period of a year.

Features of the biofilm coating include:

• Can be applied through spray coating
• Lasts for up to 365 days
• Composition may be adjusted to specific needs of different environments

Other potential applications include:

• Air-conditioning or HVAC systems in residential or commercial buildings / automobiles
• Filters
• Wastewater treatment units

Benefits of this biofilm coating technology include:

• Eco-friendly biotechnology
• Improved indoor air quality for all