Here are the changes you'll need to make to your mothur tool suite.
Add the following datatypes.conf.xml file to your repository.
<?xml version="1.0"?>
<datatypes>
<datatype_files>
<datatype_file name="metagenomics.py"/>
</datatype_files>
<registration>
<datatype extension="otu" type="galaxy.datatypes.metagenomics:Otu" display_in_upload="true"/>
<datatype extension="list" type="galaxy.datatypes.metagenomics:OtuList" display_in_upload="true"/>
<datatype extension="sabund" type="galaxy.datatypes.metagenomics:Sabund" display_in_upload="true"/>
<datatype extension="rabund" type="galaxy.datatypes.metagenomics:Rabund" display_in_upload="true"/>
<datatype extension="shared" type="galaxy.datatypes.metagenomics:SharedRabund" display_in_upload="true"/>
<datatype extension="relabund" type="galaxy.datatypes.metagenomics:RelAbund" display_in_upload="true"/>
<datatype extension="names" type="galaxy.datatypes.metagenomics:Names" display_in_upload="true"/>
<datatype extension="design" type="galaxy.datatypes.metagenomics:Design" display_in_upload="true"/>
<datatype extension="summary" type="galaxy.datatypes.metagenomics:Summary" display_in_upload="true"/>
<datatype extension="groups" type="galaxy.datatypes.metagenomics:Group" display_in_upload="true"/>
<datatype extension="oligos" type="galaxy.datatypes.metagenomics:Oligos" display_in_upload="true"/>
<datatype extension="align" type="galaxy.datatypes.metagenomics:SequenceAlignment" display_in_upload="true"/>
<datatype extension="accnos" type="galaxy.datatypes.metagenomics:AccNos" display_in_upload="true"/>
<datatype extension="map" type="galaxy.datatypes.metagenomics:SecondaryStructureMap" display_in_upload="true"/>
<datatype extension="align.check" type="galaxy.datatypes.metagenomics:AlignCheck" display_in_upload="true"/>
<datatype extension="align.report" type="galaxy.datatypes.metagenomics:AlignReport" display_in_upload="true"/>
<datatype extension="filter" type="galaxy.datatypes.metagenomics:LaneMask" display_in_upload="true"/>
<datatype extension="dist" type="galaxy.datatypes.metagenomics:DistanceMatrix" display_in_upload="true"/>
<datatype extension="pair.dist" type="galaxy.datatypes.metagenomics:PairwiseDistanceMatrix" display_in_upload="true"/>
<datatype extension="square.dist" type="galaxy.datatypes.metagenomics:SquareDistanceMatrix" display_in_upload="true"/>
<datatype extension="lower.dist" type="galaxy.datatypes.metagenomics:LowerTriangleDistanceMatrix" display_in_upload="true"/>
<datatype extension="ref.taxonomy" type="galaxy.datatypes.metagenomics:RefTaxonomy" display_in_upload="true">
<converter file="ref_to_seq_taxonomy_converter.xml" target_datatype="seq.taxonomy"/>
</datatype>
<datatype extension="seq.taxonomy" type="galaxy.datatypes.metagenomics:SequenceTaxonomy" display_in_upload="true"/>
<datatype extension="rdp.taxonomy" type="galaxy.datatypes.metagenomics:RDPSequenceTaxonomy" display_in_upload="true"/>
<datatype extension="cons.taxonomy" type="galaxy.datatypes.metagenomics:ConsensusTaxonomy" display_in_upload="true"/>
<datatype extension="tax.summary" type="galaxy.datatypes.metagenomics:TaxonomySummary" display_in_upload="true"/>
<datatype extension="freq" type="galaxy.datatypes.metagenomics:Frequency" display_in_upload="true"/>
<datatype extension="quan" type="galaxy.datatypes.metagenomics:Quantile" display_in_upload="true"/>
<datatype extension="filtered.quan" type="galaxy.datatypes.metagenomics:FilteredQuantile" display_in_upload="true"/>
<datatype extension="masked.quan" type="galaxy.datatypes.metagenomics:MaskedQuantile" display_in_upload="true"/>
<datatype extension="filtered.masked.quan" type="galaxy.datatypes.metagenomics:FilteredMaskedQuantile" display_in_upload="true"/>
<datatype extension="axes" type="galaxy.datatypes.metagenomics:Axes" display_in_upload="true"/>
<datatype extension="sff.flow" type="galaxy.datatypes.metagenomics:SffFlow" display_in_upload="true"/>
</registration>
</datatypes>
I'm probably not correctly handling the converter for your ref.taxonomy data type - I've not been able to find the ref_to_seq_taxonomy_converter.xml file. Can you pass it along to me so I can see if I have some debugging to do?
Also, I've eliminated the following entry from your README in the above file because the Newick class is not included in your metagenomics.py class module. It seems you may have include the Newick class in your local copy of ~/lib/galaxy/datatypes/data.py. If your tools use this class, it should be added to either your metagenomics.py class file or another class file in your repository and the value of the "type" attribute in the following should be changed accordingly.
<datatype extension="tre" type="galaxy.datatypes.data:Newick" display_in_upload="true"/>