Multiple syntrophic interactions in a terephthalate-degrading methanogenic consortium.
Terephthalate (TA) is one of the top 50 chemicals produced worldwide. Its production results in a TA-containing wastewater that is treated by anaerobic processes through a poorly understood methanogenic syntrophy. Using metagenomics, we characterized the methanogenic consortium inside a hyper-mesophilic (that is, between mesophilic and thermophilic), TA-degrading bioreactor. We identified genes belonging to dominant Pelotomaculum species presumably involved in TA degradation through decarboxylation, dearomatization, and modified β-oxidation to H(2)/CO(2) and acetate. These intermediates are converted to CH(4)/CO(2) by three novel hyper-mesophilic methanogens. Additional secondary syntrophic interactions were predicted in Thermotogae, Syntrophus and candidate phyla OP5 and WWE1 populations. The OP5 encodes genes capable of anaerobic autotrophic butyrate production and Thermotogae, Syntrophus and WWE1 have the genetic potential to oxidize butyrate to CO(2)/H(2) and acetate. These observations suggest that the TA-degrading consortium consists of additional syntrophic interactions beyond the standard H(2)-producing syntroph-methanogen partnership that may serve to improve community stability.
Lykidis
Athanasios
A
Joint Genome Institute, Lawrence National Berkeley Laboratory, Walnut Creek, CA, USA.
Chen
Chia-Lung
CL
Tringe
Susannah G
SG
McHardy
Alice C
AC
Copeland
Alex
A
Kyrpides
Nikos C
NC
Hugenholtz
Philip
P
Macarie
Hervé
H
Olmos
Alejandro
A
Monroy
Oscar
O
Liu
Wen-Tso
WT
D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D017753:Ecosystem; D019605:Euryarchaeota / Q000235:genetics / Q000378:metabolism; D054892:Metagenome / Q000235:genetics; D008697:Methane / Q000378:metabolism; D010459:Peptococcaceae / Q000378:metabolism; D010795:Phthalic Acids / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics
D010795:Phthalic Acids; D012336:RNA, Ribosomal, 16S; C011363:terephthalic acid; D008697:Methane