community structure of benthic bacteria of the humboldt current ecosystem
DESCRIPTION
Census of Marine Life (CoML) / Sloan Foundation International Census of Marine Microbes (ICoMM) & Keck Foundation) PROGRAM: “ Microbial Population Structure of the World’s Oceans”. COMMUNITY STRUCTURE OF BENTHIC BACTERIA OF THE HUMBOLDT CURRENT ECOSYSTEM. - PowerPoint PPT PresentationTRANSCRIPT
COMMUNITY STRUCTURE OF BENTHIC BACTERIA OF THE
HUMBOLDT CURRENT ECOSYSTEMV. A. GALLARDO, C. ESPINOZA, A. FONSECA
Departamento de OceanografíaUniversidad de Concepción
Census of Marine Life (CoML) / Sloan FoundationInternational Census of Marine Microbes (ICoMM) & Keck Foundation)
PROGRAM: “Microbial Population Structure of the World’s Oceans”
Cape Town, June - 2009
ICoMM´S PROGRAM:“MICROBIAL POPULATION STRUCTURE OF THE
WORLD’S OCEANS”• With funding from the W.M. Keck Foundation, ICoMM
established a facility for generating V-6 tag rRNA gene sequences from Bacteria and Archaea at the Marine Biological Laboratory in Woods Hole, MA, USA.
• Adopted a massively-parallel, 454-based tag sequencing strategy that allows extensive study of marine microbial communities (not only of dominant forms).
• This strategy is based on sequencing of hypervariable regions of the SSU rRNA gene (in our case V6).
• Allows to measure both abundance and taxa richness• Allows efficient comparisons of their composition and
structure.
METHODOLOGY
• The Genome Sequencer™ GS20 System from 454 Life Sciences™ and Roche Applied Science is used.
• It is a sequencing platform suitable for a wide range of applications, in this particular case for small RNA analysis and amplicon sequencing.
• The Genome Sequencer FLX is built upon 454 Sequencing™ technology that allows 200–300 bp read lengths and very high single-read accuracy.
• One application in which the technology is accelerating the field’s understanding is metagenomics.
METHODOLOGY (cont.)• The GS20 system uses DNA-capture beads that catch on average
one short single-stranded template • Beads are distributed on a solid-phase sequencing substrate (a
PicoTiterPlateTM) with 1.6 million wells.• Each well can hold a bead and additional reagents, including
polymerase, luciferase, and ATP sulfurylase. • The template is then copied millions of times in an oil emulsion
PCR (emPCR). • Microfluidics cycle each of the four nucleotide triphosphates over
the PicoTiterPlateTM. • Incorporation of a nucleotide releases pyrophosphate, the
substrate for a luminescence reaction which is recorded with a cooled CCD camera.
• The record of intensity of each flow of a nucleotide is a flow-gram analogous to a chromatogram that reports the order of A, C, G and T residues from a DNA sequencing template.
THE GENOME SEQUENCER FLX GS20
•Supports a number of formats allowing users to customize the nr. of samples /instrument run and the nr. of reads/sample.
•A single run can be physically divided into 2, 4 or 16 samples with 210,000 reads per sample,•70,000 reads per sample and 12,000 reads per sample.
ICoMM´S:“UNVEILING THE OCEAN’S HIDDEN MAJORITY
THROUGH 454 TAG SEQUENCING”
• Apr. 2007 – Call for proposals• Jun. 2007 –Presentation of proposals• Nov. 2007 – Our proposal highly rated, approved
for 16 samples (42 projects in total)• Dec. 2007 – First sampling.• Dec. 2008 – Fourth and last sampling.• Mar. 2009 - Full database available in VAMPS.
HUMBOLDT PROPOSAL
• Proposal to apply the 454 tag sequencing technology to sediment microbial communities
under the influence of the oxygen minimum zone of an Eastern Boundary Current ecosystem: the
Humboldt marine ecosystem.
SAMPLING STATIONS
“SPECIES” OF BACTERIA
• The method treats each V6-rRNA tag as a proxy for the presence of an organism (whatever taxon is warranted), i.e., species, genus, family, order, class or phylum:
• Allows the identification of the different kinds of taxa and their abundance in a community.
m
TOTAL NROFSEQS =351,751
Revised: April 2nd 2009
SPRING
SPRING
SUMMER
WINTER
40 PHYLA (294,839 tag seqs., 95%)
TOTAL326,344 tag seqs.
% PHYLA
TOTAL326,344 tag seqs.
42 CLASSES (228,784 tag seqs., 70%)
% CLASSES
TOTAL326,344 tag seqs.
89 ORDERS (185,002 tag seqs, 58%)
232 FAMILIES (147,631 tag seqs., 45%)
TOTAL326,344 tag seqs.
671 GENERA (68,610 tag seqs., 21%)
% DOMINANCE
RAREFACTION - STA. 1 (15m)Rarefaction Plot - Phyla - ST 1
SP 1
SU
WI
SP 2
ES
(n)
n
0
10
20
30
40
50
0 200 400 600 800
PHYLA CLASSES ORDERS
FAMILIES GENERA
RAREFACTION – STA. 4 (27m)Rarefaction Plot - Phyla - ST 4
SP 1
SU
WI
SP 2
ES
(n)
n
0
10
20
30
40
50
0 100 200 300 400 500 600
Rarefaction Plot - Classes - ST 4
SP 1
SU
WI
SP 2
ES
(n)
n
0
10
20
30
40
50
0 100 200 300 400 500 600
PHYLA CLASSES ORDERS
FAMILIES GENERA
RAREFACTION – STA. 7 (35m)Rarefaction Plot - Phyla - ST 7
SP 1
SU
WI
SP 2
ES
(n)
n
0
10
20
30
40
50
0 100 200 300 400 500
RAREFACTION- STA. 18 (88m)
Our undescribed as yet spirochaete
FILMED BY THOMAS ISHOEY AT SYNTHETIC GENOMICS, 2008
BACTERIAL MAT
EDITION: CAROLA ESPINOZA 2008
HYPOXIC / ANOXIC ZONES
DEAD ZONES?
THANKS