{OTU_table} R# Documentation

OTU_table

require(GCModeller);

#' Tools for handling OTU table data
imports "OTU_table" from "metagenomics_kit";

Tools for handling OTU table data

Operational taxonomic unit (OTU)

OTU's are used to categorize bacteria based on sequence similarity.

In 16S metagenomics approaches, OTUs are cluster of similar sequence variants of the
16S rDNA marker gene sequence. Each of these cluster is intended to represent a
taxonomic unit of a bacteria species or genus depending on the sequence similarity
threshold. Typically, OTU cluster are defined by a 97% identity threshold of the 16S
gene sequences to distinguish bacteria at the genus level.

Species separation requires a higher threshold Of 98% Or 99% sequence identity, Or
even better the use Of exact amplicon sequence variants (ASV) instead Of OTU sequence
clusters.

.NET clr type export
OTU_table: OTUTable

OTU table (sequence count table)

A OTU table contains the number of sequences that are observed for each taxonomic
unit (OTUs) in each samples. Columns usually represent samples and rows represent
genera or species specific taxonomic units (OTUs). OTU tables are often saved as
BIOM formatted files.

### Limited taxonomic resolution

OTU resolution depends On the 16S approach which has some limits In distinguishing at
the species level, For example,

Escherichia coli And Shigella spp. share almost identical 16S rRNA gene sequences.

Alternative approaches are developed To achieve higher resolution up To strain level
by considering larger Or complete sets Of genes.


.NET clr function exports
relative_abundance

Transform abundance data in an otu_table to relative abundance, sample-by-sample.

Transform abundance data into relative abundance, i.e. proportional data. This is
an alternative method of normalization and may not be appropriate for all datasets,
particularly if your sequencing depth varies between samples.
filter

filter the otu data which has relative abundance greater than the given threshold
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