Measurement of ice nucleation-active bacteria on plants and in precipitation by quantitative PCR

dc.contributor.author	Hill, TCJ	en
dc.contributor.author	Moffett, BF	en
dc.contributor.author	DeMott, PJ	en
dc.contributor.author	Georgakopoulos, DG	en
dc.contributor.author	Stump, WL	en
dc.contributor.author	Franc, GD	en
dc.date.accessioned	2014-06-06T06:53:05Z
dc.date.available	2014-06-06T06:53:05Z
dc.date.issued	2014	en
dc.identifier.issn	00992240	en
dc.identifier.uri	http://dx.doi.org/10.1128/AEM.02967-13	en
dc.identifier.uri	http://62.217.125.90/xmlui/handle/123456789/6356
dc.subject.other	Atmospheric process	en
dc.subject.other	Biological sources	en
dc.subject.other	Environmental sample	en
dc.subject.other	Natural vegetation	en
dc.subject.other	Naturally occurring	en
dc.subject.other	Pantoea agglomerans	en
dc.subject.other	Pseudomonas syringae	en
dc.subject.other	Xanthomonas campestris	en
dc.subject.other	Bacteria	en
dc.subject.other	Genes	en
dc.subject.other	Glacial geology	en
dc.subject.other	Nucleation	en
dc.subject.other	Polymerase chain reaction	en
dc.subject.other	Snow	en
dc.subject.other	Vegetation	en
dc.subject.other	Ice	en
dc.subject.other	abundance	en
dc.subject.other	bacterium	en
dc.subject.other	glaciation	en
dc.subject.other	high temperature	en
dc.subject.other	ice	en
dc.subject.other	measurement method	en
dc.subject.other	plant	en
dc.subject.other	polymerase chain reaction	en
dc.subject.other	precipitation (climatology)	en
dc.subject.other	vegetation structure	en
dc.title	Measurement of ice nucleation-active bacteria on plants and in precipitation by quantitative PCR	en
heal.type	journalArticle	en
heal.identifier.primary	10.1128/AEM.02967-13	en
heal.publicationDate	2014	en
heal.abstract	Ice nucleation-active (INA) bacteria may function as high-temperature ice-nucleating particles (INP) in clouds, but their effective contribution to atmospheric processes, i.e., their potential to trigger glaciation and precipitation, remains uncertain. We know little about their abundance on natural vegetation, factors that trigger their release, or persistence of their ice nucleation activity once airborne. To facilitate these investigations, we developed two quantitative PCR (qPCR) tests of the ina gene to directly count INA bacteria in environmental samples. Each of two primer pairs amplified most alleles of the ina gene and, taken together, they should amplify all known alleles. To aid primer design, we collected many new INA isolates. Alignment of their partial ina sequences revealed new and deeply branching clades, including sequences from Pseudomonas syringae pv. atropurpurea, Ps. viridiflava, Pantoea agglomerans, Xanthomonas campestris, and possibly Ps. putida, Ps. auricularis, and Ps. poae. qPCR of leaf washings recorded ̃108 ina genes g-1 fresh weight of foliage on cereals and 105 to 107 g-1 on broadleaf crops. Much lower populations were found on most naturally occurring vegetation. In fresh snow, ina genes from various INA bacteria were detected in about half the samples but at abundances that could have accounted for only a minor proportion of INP at -10°C (assuming one ina gene per INA bacterium). Despite this, an apparent biological source contributed an average of ̃85% of INP active at -10°C in snow samples. In contrast, a thunderstorm hail sample contained 0.3 INA bacteria per INP active at -10°C, suggesting a significant contribution to this sample. © 2014, American Society for Microbiology.	en
heal.journalName	Applied and Environmental Microbiology	en
dc.identifier.issue	4	en
dc.identifier.volume	80	en
dc.identifier.doi	10.1128/AEM.02967-13	en
dc.identifier.spage	1256	en
dc.identifier.epage	1267	en