Indoor heterogeneous photochemistry of molds and their contribution to HONO formation.

To better understand the impact of molds on indoor air quality, we studied the photochemistry of microbial films made by Aspergillus niger species, a common indoor mold. Specifically, we investigated their implication in the conversion of adsorbed nitrate anions into gaseous nitrous acid (HONO) and nitrogen oxides (NO ), as well as the related VOC emissions under different indoor conditions, using a high-resolution proton transfer reaction-time of flight-mass spectrometer (PTR-TOF-MS) and a long path absorption photometer (LOPAP). The different mold preparations were characterized by the means of direct injection into an Orbitrap high-resolution mass spectrometer with a heated electrospray ionization (ESI-Orbitrap-MS).

Influence of indoor chemistry on the emission of mVOCs from Aspergillus niger molds.

People spend 80% of their time indoors exposed to poor air quality due to mold growth in humid air as well as human activities (painting, cooking, cleaning, smoking…). To better understand the impact of molds on indoor air quality, we studied the emission of microbial Volatile Organic Compounds (mVOCs) from Aspergillus niger, cultivated on malt agar extract, using a high-resolution proton transfer reaction- time of flight- mass spectrometer (PTR-TOF-MS). These emissions were studied for different cultivation time and indoor relative humidities.

Reduced microbial diversity induces larger volatile organic compound emissions from soils.

Microorganisms in soil are known to be a source and a sink of volatile organic compounds (VOCs). The role of the microbial VOCs on soil ecosystem regulation has been increasingly demonstrated in the recent years. Nevertheless, little is known about the influence of the microbial soil community structure and diversity on VOC emissions.

Profiles of volatile organic compound emissions from soils amended with organic waste products.

Volatile Organic Compounds (VOCs) are reactive compounds essential to atmospheric chemistry. They are mainly emitted by living organisms, and mostly by plants. Soil microbes also contribute to emissions of VOCs.