Culturable and metagenomic approaches of wheat bran and wheat straw phyllosphere's highlight new lignocellulolytic microorganisms. (1st June 2022)

• Record Type: Journal Article
• Authors: Besaury, L.; Rémond, C.
• Is Part Of: Letters in applied microbiology. Volume 74:Number 6(2022)
• Page Start: 840
• Page End: 850
• Publication Date: 2022-06-01
• Subjects: CAZymes -- biotechnology -- lignocellulose -- phyllosphere; Microbiology -- Periodicals; 660.62
• DOI: 10.1111/lam.13676
• Languages: English
• ISSNs: 0266-8254

Abstract

Abstract: The phyllosphere, defined as the aerial parts of plants, is one of the most prevalent microbial habitats on earth. The microorganisms present on the phyllosphere can have several interactions with the plant. The phyllosphere represents then a unique niche where microorganisms have evolved through time in that stressful environment and may have acquired the ability to degrade lignocellulosic plant cell walls in order to survive to oligotrophic conditions. The dynamic lignocellulolytic potential of two phyllospheric microbial consortia (wheat straw and wheat bran) has been studied. The microbial diversity rapidly changed between the native phyllospheres and the final degrading microbial consortia after 48 h of culture. Indeed, the initial microbial consortia was dominated by the Ralstonia (35·8%) and Micrococcus (75·2%) genera for the wheat bran and wheat straw whereas they were dominated by Candidatus phytoplasma (59%) and Acinetobacter (31·8%) in the final degrading microbial consortia respectively. Culturable experiments leading to the isolation of several new lignocellulolytic isolates (belonging to Moraxella and Atlantibacter genera) and metagenomic reconstruction of the microbial consortia highlighted the existence of an unpredicted microbial diversity involved in lignocellulose fractionation but also the existence of new pathways in known genera (presence of CE2 for Acinetobacter, several AAs for Pseudomonas and several GHs for Bacillus in different metagenomes‐assembled genomes). The phyllosphere from agricultural co‐products represents then a new niche as a lignocellulolytic degrading ecosystem. Abstract: Significance and Impact of the Study : The phyllosphere's co‐products represent then a niche where microorganisms have acquired the ability to degrade lignocellulosic plant cell walls in order to survive oligotrophic conditions. This manuscript highlights by a polyphasic study the role played by unprecedently characterized lignocellulytic µorganisms which are present only on the phyllophere of the co‐products (wheat bran and wheat straw) and may present new specificities in order to degrade that lignocellulosic plant cell wall. Moreover, new enzymatic and metabolic pathways are present among those phyllospheric µorganisms. It also highlights the degradation of some specific chemical functions in the different consortia (wheat bran and wheat straw) depending on the microbial diversity. The whole work is thus promising for the context of biomass refinery.