[P004] Poster

1:00 PM - 1:50 PM JST(4:00 AM - 4:50 AM UTC)

[P02-258] Identification of a novel thermotolerant lipase and its producer from mesophilic anaerobic digestion sludge by functional metaproteomics

○Riku Sakurai¹, Yasuhiro Fukuda², Chika Tada² (1. National Institute of Advanced Industrial Science and Technology (Japan), 2. Tohoku University (Japan))

Keywords:

Lipase,Anaerobic digestion,Zymography,Functional metaproteomics

Lipases are widely used biocatalysts with applications across the agricultural, chemical, food-processing, and biofuel industries. Although microbial lipases are particularly attractive due to their catalytic diversity and high production yields, most characterized enzymes originate from aerobic microorganisms. In contrast, lipases from anaerobic environments remain poorly understood. In this study, we applied a functional metaproteomic approach and identified a novel lipase and its producer from anaerobic digestion sludge. Remarkably, the identified lipase showed no detectable sequence similarity to known lipases. Instead, in silico analyses suggested that it was derived from an ABC transporter substrate-binding protein. This unprecedented enzyme displayed extremophile-like properties, exhibiting maximal activity at 97.5 ℃ and pH 11. We further reconstructed a metagenome-assembled genome encoding this lipase and found that it likely represents a novel genus closely affiliated with Candidatus Scatomorpha. Metabolic reconstruction indicated that this microorganism degrades extracellular lipids and utilizes the hydrolysate glycerol. Collectively, our findings expand the known diversity of lipases in anaerobic ecosystems and demonstrate the power of functional metaproteomics for discovering previously unrecognized biocatalysts and linking them to their microbial producers.