MDA-associated Amplification bias has been improved for eukaryotic cells using a technique called MALBAC [32], but these improvements have yet to be shown for prokaryotic genomes and still rely on random, or morphologically based, cell sorting. Such random sorting of single microbial cells from complex mixtures is expected to learn more bias against rare species and may require sorting and find more sequencing of hundreds to thousands

of cells before a rare genome can be obtained. Increased input template number can overcome MDA amplification bias, or difficulties in processing and sorting single cells from biofilms, and provide near complete genome coverage. Potential methods for accomplishing this include inducing artificial polyploidy or using gel microdroplets [24, 33]. However, in both of these cases, rare species may still be missed if sufficient GSK1838705A ic50 numbers of single cells cannot be sorted. This has been partially addressed in a recently published “mini-metagenomics” approach. MDA product coverage was improved by creating bacterial pools by flow cytometry, with ~100 bacteria in each pool. Screening of these pools for 16S rDNA sequences of the bacterial species of interest, followed by deep sequencing of the positive pools, allowed assembly of a relatively complete

genome from different pools containing the same 16S RNA sequences [34]. An alternative approach to simultaneously address both amplification bias and isolate rare species is to use antibodies recognizing specific microorganisms within microbial communities to enrich and/or subtract bacterial species prior to sequencing.

We hypothesized that enrichment by selective sorting in this way could provide a powerful method for significantly increasing input template number to obtain complete genomes of low abundance species, akin to creating a small microbiome in which all members expressed a single target recognized by the antibody of interest. In the present work, we developed a selection and screening pipeline using phage display and flow cytometry to isolate a single chain Fv (scFv) antibody that can: i) identify MycoClean Mycoplasma Removal Kit a bacterial species, Lactobacillus acidophilus, with extreme specificity; and ii) be applied to a microbiome, using fluorescence activated cell sorting (FACS), to identify, enrich, and deplete targeted species from bacterial mixtures. We further demonstrated that if this approach was applied to a mock community containing L. acidophilus, rather than the pure single species, antibodies recognizing L. acidophilus could be isolated. This phage display selection method is highly adaptable to recognition of any organism and provides a unique tool for dissection and sequencing of rare species from complex microbiomes. Results Selection against intact bacteria using phage display and screening by flow cytometry We chose the probiotic Lactobacillus acidophilus ATCC 4356 as a target for our approach. Lactobacilli such as sp.