Bacterial spores are in the air everywhere you go, including those that will serve to initiate the nitrogen cycle.
They do reproduce quite fast too. Adding a few additional spores in a bottle may help though.
The sea surface microlayer as a source of viral and bacterial enrichment in marine aerosols
http://www.sciencedirect.com/scienc...serid=10&md5=40b38327342e6565f15ebec8990a7ab9
Josephine Y. Aller, , Marina R. Kuznetsova, Christopher J. Jahns and Paul F. Kemp
Received 26 April 2004; revised 4 October 2004; accepted 28 October 2004. Available online 13 December 2004.
Abstract
Marine aerosols are formed primarily by the eruption of rising bubbles through the sea-surface microlayer (SML), and aerosol formation is the main vector for transport of bacteria and viruses across the air–sea interface. The processes by which materials are transported to and through the SML to the atmosphere results in an enrichment in the SML of microbial and other organisms. We evaluated concentrations of marine bacteria and viruses in natural aerosols and in those simulated by bubbling sea sprays and compared them to the concentrations in SML (200– thick) and in subsurface water. Association of microorganisms with transparent gel-like organic particles and physiological status of bacteria were also assessed. We found a 15–25-fold enrichment in bacteria and viruses during transport from subsurface waters to the SML, and then into the atmosphere. The majority of microorganisms in aerosols were found embedded in the organic particles. Large portions of microorganisms in the SML were also associated with the particles, while in subsurface waters most of them were free-living. A larger percentage of damaged and less active bacterial cells occur in the microlayer than in subsurface waters, and preliminary data suggest that an even greater percentage occurs in aerosols. Our data support the idea that the SML in a major source of microorganisms entering the atmosphere from water bodies. Aerosolization is potentially an important long-distance dispersal mechanism and may account for observed cosmopolitan distributions of some bacteria.
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Bacteria in the global atmosphere –
Part 1: Review and synthesis of literature
data for different ecosystems
http://atmos-chem-phys-discuss.net/9/10777/2009/acpd-9-10777-2009.pdf
S. M. Burrows, W. Elbert, M. G. Lawrence, and U. P¨oschl
Max Planck Institute for Chemistry, Mainz, Germany
Received: 6 March 2009 – Accepted: 11 April 2009 – Published: 4 May 2009
Correspondence to: S. M. Burrows (susannah.burrows@mpic.de)
Published by Copernicus Publications on behalf of the European Geosciences Union.
From it:
The number of prokaryotic cells (organisms that lack a cell nucleus, including bacteria
and archaea) in forest soils has been estimated at 4×107 g−1, while the number of
prokaryotic cells in all other soils (including desert and cultivated soils) is believed to be
about 2×109 g−1 5 (Whitman et al., 1998). Bacteria also live on leaves and other aerial
plant surfaces, with concentrations on leaves of about 108 g−1 (Lindow and Brandl,
2003). The global population of microbes on leaves may be as many as 1026 cells (Morris
and Kinkel, 2002).
The published measurements listed in Table C give an overview of the concentra10
tions of bacteria in near-surface air in various locations around the world, organized by
ecosystem or land use type. Although the picture is still incomplete, some rough estimates
of concentrations can be obtained from this table (Table 1, discussed below).
In choosing these numbers, we considered only a selection of the available data. In
general, measurements of total bacterial concentration were given preference. Where
15 only culturable bacteria concentrations were available, an attempt was made to estimate
an appropriate scaling factor by comparing other measurements from the same
study with total concentration measurements in similar environments.
Table 1. Estimates of total mean bacterial concentration in near-surface air of various ecosystem
types (m−3). See Sect. 8 for details.
Ecosystem Best estimatea Low estimatea High estimate
coastalb 7.6×104 2.3×104 1.3×105
cropsb 1.1×105 4.1×104 1.7×105
desertsc 1.6×102 3.8×104
forestsd 5.6×104 3.3×104 8.8×104
grasslandsb,e 1.1×105 2.5×104 8.4×105
land icef 1×104
seasb,f,g 1×104 1×101 8×104
shrubse,f 3.5×105 1.2×104 8.4×105
tundrad,f 1.2×104 5.6×104
wetlandsh 9×104 2×104 8×105
urban (curbside)d 6.5×105 4.4×105 9.2×105
urban parkb 1.2×105 4.8×104 1.9×105