Microbial and “de novo” transformation of dicarboxylic acids by three airborne fungi

Abstract

Micro-organisms and organic compounds of biogenic or anthropogenic origins are important constituents of atmospheric aerosols, which are involved in atmospheric processes and climate change. In order to investigate the role of fungi and their metabolisation activity, we collected airborne fungi using a biosampler in an urban location of Montreal, Quebec, Canada (45 degrees 28' N, 73 degrees 45' E). After isolation on Sabouraud dextrose agar, we exposed isolated colonies to dicarboxylic acids (C(2)-C(7)), a major group of organic aerosols and monitored their growth. Depending on the acid, total fungi numbers varied from 35 (oxalic acid) to 180 CFU/mL (glutaric acid). Transformation kinetics of malonic acid, presumably the most abundant dicarboxylic acid, at concentrations of 0.25 and 1.00 mM for isolated airborne fungi belonging to the genera Aspergillus, Penicillium, Eupenicillium, and Thysanophora with the fastest transformation rate are presented. The initial concentration was halved within 4.5 and 11.4 days. Other collected fungi did not show a significant degradation and the malonic acid concentration remained unchanged (0.25 and 1.00 mM) within 20 days. Degradation of acid with formation of metabolites was followed using high performance liquid chromatography-ultraviolet detection (HPLC/UV) and gas chromatography-mass spectrometry (GC/MS), as well as monitoring of (13)C labelled malonic acid degradation with solid-state nuclear magnetic resonance spectroscopy (NMR). Using GC/MS we identified two processes driving chemical modifications of organic aerosol solutions: (I) formation of metabolites within several days, and (II) rapid release (< or =2 min) of organic molecules from fungal species upon the insertion of taxa in organic aerosol solutions. Metabolites included aromatic compounds and alcohols (e.g. trimethylbenzene and butanol). Potential atmospheric implications of our results are discussed.

Global fungal spore emissions, review and synthesis of literature data

“…Also the time span over the year varied from study to study: some only measured on one single day, e.g. Côté et al (2008), others even over several years continuously, e.g. Mallo et al (2010).…”

“…These cases were treated as single measurement points. Beaumont et al (1985) Forest 258 n/a n/a 52 n/a n/a yes Côté et al (2008) Forest 615 492 738 123 98 148 yes Fisar et al (1990) Forest 17 n/a n/a 3 n/a n/a Both methods Gregory (1967) Forest n/a n/a 43 300 n/a n/a 8660 no Gregory (1967) Forest 5250 n/a n/a n/a n/a 1050 no Gregory (1967) Forest n/a 766 n/a 153 n/a n/a no Kasprzyk and Worek (2006) Forest 2144 n/a n/a 429 n/a n/a no Kasprzyk and Worek (2006) Forest 2183 n/a n/a 437 n/a n/a no Kasprzyk and Worek (2006) Forest 2093 n/a n/a 419 n/a n/a no Kasprzyk and Worek (2006) Forest 2146 n/a n/a 429 n/a n/a no Marks et al n/a n/a 113 n/a n/a no Winiwarter et al (2009) Forest 49 n/a n/a 10 n/a n/a Elbert et al (2007) Tropical forest 12 476 4764 20 188 2495 953 4038 no Griffin et al (2001) Tropical forest 45 n/a n/a 9 n/a n/a no Griffin et al (2003) Tropical forest 0 n/a n/a 0 n/a n/a yes Griffin et al (2003) Tropical forest 57 n/a n/a 11 n/a n/a yes Griffin et al (2003) Tropical forest 9 5 20 2 1 4 yes Griffin et al (2003) Tropical forest Prospero et al (2005) Tropical forest 92 n/a n/a 18 n/a n/a yes Prospero et al (2005) Tropical forest 213 n/a n/a 43 n/a n/a yes Pady and Kapica (1955) Tropical forest 37 6 67 7 1 13 both methods Pady and Kapica (1955) Tropical forest 230 170 291 46 24 58 both methods Pady and Kapica (1955) Tropical forest 6 6 6 1 1 1 both methods Pady and Kapica (1955) Tropical forest 44 39 49 9 8 10 both methods Pady and Kapica (1955) Tropical forest 16 n/a n/a 3 n/a n/a both methods Pady and Kapica (1955) Tropical forest 31 n/a n/a 6 n/a n/a both methods Wu et al (2007) Tropical forest 2233 n/a n/a 447 n/a n/a yes Wu et al (2007) Tropical forest 2278 n/a n/a 456 n/a n/a yes Burch and Levetin (2002) Shrub 50 000 n/a n/a 10 000 n/a n/a no Herrero et al (2006) Shrub 609 n/a n/a 122 n/a n/a no DiGiorgio et al (1996) Shrub 92 n/a n/a 18...…”

“…Sampling Device Airflow Sample Period/Number of Samplings Amato et al (2005) Single stage cloud collectors n/a 2 Samplings Amato et al (2007) Sterilised cloud droplet impactor n/a 7 cloud events Bauer et al (2002a) Active cloud water sampler n/a 3 cloud events, 8 samplings Beaumont et al (1985) Andersen Sampler model 0101 28.3 l min −1 1981-1983/weekly, 3 samplings per day Burch and Levetin (2002) Burkart volumetric spore trap n/a four days in September Côté et al (2008) 12.5 l min −1 6.5 h/one sampling Davies et al (1963) Hirst-type spore trap 10 l min −1 n/a Herrero et al (2006) Hirst-type spore trap (Burkart) n/a year 2003/continuous samplings DiGiorgio et al (1996) Hirst-type spore trap (Burkart) 40 l min −1 one year/2 samplings a week Elbert et al (2007) Rotating impactor, isokinetic jet impactor n/a 2001/continuous measurements Fisar et al (1990) Single stage large-volume impactor 42 l min −1 50-200l per sample, i.e. a few minutes Glikson et al (1995) Teflon filters for PM10 n/a 4-8 1992/daily samplings Gregory (1952) May cascade impactor 10 l min −1 24 h Griffin et al (2001) Filter samples 9.3 l min −1 18-28 July 2000 5 samplings Griffin et al (2003) Filter membrane 6.5-28.4 l min −1 18 July 2000-8 August 2001 Griffin et al (2006) Filter membrane 1.9-17.4 l min −1 06:30-18:45 UTC/2-3 air samplings Griffin et al (2007) Membrane Filtration n/a 3-10 2002/continuous samplings Griffin (2007) Data taken from multiple sources n/a n/a Hamilton (1959) Hirst-type spore trap 10 l min −1 5-9 1954/15 min per day Ho et al (2005) Hirst-type spore trap 10 l min −1 continuous from 1993 to 1996 Kasprzyk and Worek (2006) Hirst-type spore trap (Lanzoni) 10 l min −1 one year/continuous samplings Kellogg et al (2004) in-house designed system 10 l min −1 n/a Lau et al (2006) Graseby GMWT 2200 would be of help in order to minimize measurement biases and allow for better intercomparability of measurements.…”

Arctic microbial and next-generation sequencing approach for bacteria in snow and frost flowers: selected identification, abundance and freezing nucleation

“…Recently, the increase in the number of storms has been associated with the efficient long-range transport of dust, microbial and other chemicals to the Arctic regions (Clarke et al, 2001;Grousset et al, 2003;Uno et al, 2009). During long distance transportation, air masses may undergo chemical and physical transformation under extreme environmental conditions such as high levels of solar radiation, multiple freeze-thaw cycles, relatively acidic conditions, and predominantly inorganic salts (Jickells, 1999;Ariya et al, 2002Ariya et al, , 2009Cote et al, 2008). Little is known on the effects of the photochemical and aging processes of the chemical and biological composition of dust particles, or whether chemical properties and the genomic structure of microbial entities transported with dust are altered, or mutated during long distance transport (Smith et al, 2010).…”

Atmospheric Habitable Zones in Y Dwarf Atmospheres

“…The atmospheric residence time of these organisms is highly uncertain but there is a growing body of works that show that some organisms are metabolically active, particularly in clouds (Lighthart & Shaffer 1995;Lighthart 1997;Fuzzi et al 1997;Sattler et al 2001;Côté et al 2008;Womack et al 2010;Gandolfi et al 2013). Other solar system planets have been postulated to have a habitable atmosphere.…”