Insights into the action of phylogenetically diverse microbial expansins on the structure of cellulose microfibrils

Kuvaus

Abstract Background Microbial expansins (EXLXs) are non-lytic proteins homologous to plant expansins involved in plant cell wall formation. Due to their non-lytic cell wall loosening properties and potential to disaggregate cellulosic structures, there is considerable interest in exploring the ability of microbial expansins (EXLX) to assist the processing of cellulosic biomass for broader biotechnological applications. Herein, EXLXs with different modular structure and from diverse phylogenetic origin were compared in terms of ability to bind cellulosic, xylosic, and chitinous substrates, to structurally modify cellulosic fibrils, and to boost enzymatic deconstruction of hardwood pulp. Results Five heterogeneously produced EXLXs (Clavibacter michiganensis; CmiEXLX2, Dickeya aquatica; DaqEXLX1, Xanthomonas sacchari; XsaEXLX1, Nothophytophthora sp.; NspEXLX1 and Phytophthora cactorum; PcaEXLX1) were shown to bind xylan and hardwood pulp at pH 5.5 and CmiEXLX2 (harboring a family-2 carbohydrate-binding module) also bound well to crystalline cellulose. Small-angle X-ray scattering revealed a 20–25% increase in interfibrillar distance between neighboring cellulose microfibrils following treatment with CmiEXLX2, DaqEXLX1, or NspEXLX1. Correspondingly, combining xylanase with CmiEXLX2 and DaqEXLX1 increased product yield from hardwood pulp by ~ 25%, while supplementing the TrAA9A LPMO from Trichoderma reesei with CmiEXLX2, DaqEXLX1, and NspEXLX1 increased total product yield by over 35%. Conclusion This direct comparison of diverse EXLXs revealed consistent impacts on interfibrillar spacing of cellulose microfibers and performance of carbohydrate-active enzymes predicted to act on fiber surfaces. These findings uncover new possibilities to employ EXLXs in the creation of value-added materials from cellulosic biomass.
Näytä enemmän

Julkaisuvuosi

2024

Aineiston tyyppi

Tekijät

Department of Bioproducts and Biosystems

Aleksi Zitting Orcid -palvelun logo - Tekijä

Anu Koivula - Tekijä

Emma R. Master Orcid -palvelun logo - Tekijä

Garry W. Buchko - Tekijä

Janak Sapkota - Tekijä

Kaisa Marjamaa - Tekijä

Majid Haddad Momeni - Tekijä

Natalia Maiorova - Tekijä

Paavo Penttilä Orcid -palvelun logo - Tekijä

Rosaliina Turunen - Tekijä

Salla Hiltunen - Tekijä

Vilma Jäämuru - Tekijä

University of Toronto - Muu tekijä

VTT Technical Research Centre of Finland Ltd. - Muu tekijä

Washington State University - Muu tekijä

figshare - Julkaisija

Projekti

Muut tiedot

Tieteenalat

Biokemia, solu- ja molekyylibiologia

Kieli

Saatavuus

Avoin

Lisenssi

Creative Commons Nimeä 4.0 Kansainvälinen (CC BY 4.0)

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Asiasanat

Ajallinen kattavuus

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