New method for estimating bacterial cell abundances in natural samples by use of sublimation.
We have developed a new method based on the sublimation of adenine from Escherichia coli to estimate bacterial cell counts in natural samples. To demonstrate this technique, several types of natural samples, including beach sand, seawater, deep-sea sediment, and two soil samples from the Atacama Desert, were heated to a temperature of 500 degrees C for several seconds under reduced pressure. The sublimate was collected on a cold finger, and the amount of adenine released from the samples was then determined by high-performance liquid chromatography with UV absorbance detection. Based on the total amount of adenine recovered from DNA and RNA in these samples, we estimated bacterial cell counts ranging from approximately 10(5) to 10(9) E. coli cell equivalents per gram. For most of these samples, the sublimation-based cell counts were in agreement with total bacterial counts obtained by traditional DAPI (4,6-diamidino-2-phenylindole) staining.
NASA Goddard Space Flight Center, Greenbelt, Maryland 20071, USA. daniel.p.glavin@nasa.gov.
Daniel P
DP
Glavin
H James
HJ
Cleaves
Michael
M
Schubert
Andrew
A
Aubrey
Jeffrey L
JL
Bada
D000225:Adenine / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D015169:Colony Count, Microbial / Q000295:instrumentation / Q000379:methods*; D004247:DNA / Q000032:analysis; D004783:Environmental Microbiology; D004926:Escherichia coli / Q000737:chemistry; D005456:Fluorescent Dyes; D019015:Geologic Sediments / Q000382:microbiology; D006358:Hot Temperature; D007211:Indoles; D012623:Seawater / Q000382:microbiology; D012988:Soil Microbiology; D013194:Staining and Labeling
D005456:Fluorescent Dyes; D007211:Indoles; C007293:DAPI; D004247:DNA; D000225:Adenine