38
A. Meyerdierks and F.O. Glöckner
Environmental Sample
DNA Isolation
Small Insert Library
- plasmid
- bacteriophage
Pyrosequencing
Sanger-Based
Sequencing
Screening
- sequence-based
* PCR
* hybridisation
- function based
* expression analysis
* shuttle vectors
Library Characterisation
- number of clones
- fraction of clones with inserts
- insert size
Bioinformatic
Analysis
DNA Purification
DNA Amplification
- MDA
Enrichment
- selective filtration
- density gradient centrifugation
- specific staining by fluorescenz
in situ hybridisation
& capture/sorting
- labeling of the DNA of
metabolically
active cells & capture
- enrichment culture
[-single cell/cell population
isolation ]
and/or
or
Large Insert Library
- fosmid
- BAC
and/or
Fig. 2.1 Metagenomic workflow. Steps indicated by dashed lines are optional
The genetic composition of a highly diverse microbial community can be
assessed using several different approaches. A simple inventory of genetic capabilities without gene order and phylogenetic affiliation of single genes is best obtained
by shotgun sequencing of small insert libraries (Venter et al. 2004, Tringe et al.