PLA from PolySciTech used in testing on carboxylesterases from environmental sources for industrial applications

 

High-temperature-active microbial enzymes are important biocatalysts for many industrial applications including recycling of synthetic and biobased polyesters increasingly used in textiles, fibres, coatings and adhesives. Recently, researchers from Bangor University, Institute of Catalysis, University of Toronto, University of Calgary, Russian Academy of Sciences, and Institute of Polar Sciences used Poly(D)lactide (cat# AP159), Poly(L)lactide (Cat# AP128) from PolySciTech Division of Akina, Inc. (www.polyscitech.com) to test the ability these enzymes to break down various polymers. This research holds promise to provide for industrial enzymes for a wide array of applications. Read more: Distaso, Marco A., Tatyana N. Chernikova, Rafael Bargiela, Cristina Coscoln, Peter J. Stogios, Jose L. Gonzalez, Sofia Lemak et al. "Thermophilic carboxylesterases from hydrothermal vents of the volcanic island of Ischia active on synthetic and biobased polymers and mycotoxins." bioRxiv (2022). (https://www.biorxiv.org/content/10.1101/2022.09.17.508236v1.full.pdf)

“Hydrothermal vents have a widespread geographical distribution and are of high interest for investigating microbial communities and robust enzymes for various industrial applications. We examined microbial communities and carboxylesterases of two terrestrial hydrothermal vents of the volcanic island of Ischia (Italy) predominantly composed of Firmicutes (Geobacillus and Brevibacillus spp.), Proteobacteria and Bacteroidota. High-temperature enrichment cultures with the polyester plastics polyhydroxybutyrate (PHB) and polylactic acid (PLA) resulted in an increase of Thermus and Geobacillus spp., and to some extent, Fontimonas and Schleiferia spp. The screening at 37-70°C of metagenomic fosmid library from above enrichment cultures resulted in identification and successful production in Escherichia coli of three hydrolases (IS10, IS11 and IS12), all derived from yet uncultured Chloroflexota and showing low sequence identity (33-56%) to characterized enzymes. Enzymes exhibited maximal esterase activity at temperatures 70-90°C, with IS11 showing the highest thermostability (90% activity after 20 min incubation at 80°C). IS10 and IS12 were highly substrate-promiscuous and hydrolysed all 51 monoester substrates tested. Enzymes were active with polyesters (PLA and polyethylene terephthalate model substrate, 3PET) and mycotoxin T-2 (IS12). IS10 and IS12 had a classical α/β hydrolase core domain with a serine hydrolase catalytic triad (Ser155, His280, and Asp250) in the hydrophobic active sites. The crystal structure of IS11 resolved at 2.92 Å revealed the presence of the N-terminal β-lactamase-like domain and C-terminal lipocalin domain. The catalytic cleft of IS11 includes catalytic residues Ser68, Lys71, Tyr160, and Asn162, whereas the lipocalin domain encloses the catalytic cleft like a lid contributing to substrate binding. Thus, this study has identified novel thermotolerant carboxylesterases with a broad substrate range including polyesters and mycotoxins for potential applications in biotechnology.”