The first genomic insights into the phylum were achieved in 2015, at which time the name "Modulibacteria" was proposed<ref name=":0" />. Two genomes were recovered from methanogenic sludge samples of a full-scale upflow anaerobic sludge blanket (UASB) reactor treating a high-strength organic wastewater discharged from a food-processing factory. Through a combination of genome-based metabolic reconstruction and microscopic observation, it was determined that that the two studied Modulibacteria species (''Moduliflexus flocculans'' and ''Vecturithrix granuli'') produce filamentous structures and are Gram-negative, strictly anaerobic fermenters capable of non-flagellar based gliding motility. Both have an unusually large number of sensory and response regulator genes compared to other bacteria<ref name=":0" />.
Members of the Modulibacteria phylum have been detected in a variety of environments in addition to bioreactors and hypersaline mats, includingsuch as wetland sediments ([https://www.ncbi.nlm.nih.gov/nuccore/FJ516883 FJ516883.1]), the dolphin mouth<ref>{{Cite journal|last=Bik|first=Elisabeth M.|last2=Costello|first2=Elizabeth K.|last3=Switzer|first3=Alexandra D.|last4=Callahan|first4=Benjamin J.|last5=Holmes|first5=Susan P.|last6=Wells|first6=Randall S.|last7=Carlin|first7=Kevin P.|last8=Jensen|first8=Eric D.|last9=Venn-Watson|first9=Stephanie|last10=Relman|first10=David A.|date=2016-02-03|title=Marine mammals harbor unique microbiotas shaped by and yet distinct from the sea|url=https://www.nature.com/articles/ncomms10516|journal=Nature Communications|language=en|volume=7|issue=1|pages=1–13|doi=10.1038/ncomms10516|issn=2041-1723}}</ref><ref>{{Cite journal|last=Dudek|first=Natasha K.|last2=Sun|first2=Christine L.|last3=Burstein|first3=David|last4=Kantor|first4=Rose S.|last5=Aliaga Goltsman|first5=Daniela S.|last6=Bik|first6=Elisabeth M.|last7=Thomas|first7=Brian C.|last8=Banfield|first8=Jillian F.|last9=Relman|first9=David A.|date=2017-12-18|title=Novel Microbial Diversity and Functional Potential in the Marine Mammal Oral Microbiome|url=https://www.ncbi.nlm.nih.gov/pubmed/29153320|journal=Current biology: CB|volume=27|issue=24|pages=3752–3762.e6|doi=10.1016/j.cub.2017.10.040|issn=1879-0445|pmid=29153320}}</ref>, and a tubeworm from a coldseep ([https://www.ncbi.nlm.nih.gov/nuccore/FM165273 FM165273]).
