A genome–proteome‐based approach for xylan degradation by Cohnella sp. AR92

Abstract

Several members of Cohnella genus have been reported as xylanolytic bacteria with significant capacity as carbohydrate-active enzyme producers (CAZymes), whose mechanisms involving xylan degradation are a key goal for suitable applications in bio-based industries. Using Cohnella sp. AR92 bacterium, we ensembled a genomic-proteomic approach to assess plant biomass conversion targeting its xylanolytic set of enzymes. Also, the genomic traits of the strain AR92 were compared to other Cohnella spp., showing a significant variability in terms of genome sizes and content of genes that code CAZymes. The AR92 strain genome harbours 209 CAZymes encoding sequences active on different polysaccharides, particularly directed towards xylans. Concurrent proteomic data recovered from cultures containing three kinds of lignocellulosic-derived substrates showed a broad set of xylan-degrading enzymes. The most abundant CAZymes expressed in the different conditions assayed were endo-β-1,4-xylanases belonging to the GH11 and GH10 families, enzymes that were previously proved to be useful in the biotransformation of lignocellulosic biomass derived from sugarcane as well as onto xylan-enriched substrates. Therefore, considering the large reserve of CAZymes of Cohnella sp. AR92, a xylan processing model for AR92 strain is proposed.

Microbiological Diversity and Associated Enzymatic Activities in Honey and Pollen from Stingless Bees from Northern Argentina

“…As can be seen in the dendrogram of enzymatic activities, the microorganisms that had the highest values of xylanolytic activity (>50%) were more frequently associated with high cellulolytic activity (70-100%), and they exhibited lipolytic activity to a lesser extent (Figure 3A and Supplementary Data S3). It has been reported that both xylanases and cellulases can be induced by the same substrates, resulting in the simultaneous expression of both proteins, maximizing degradation and assimilation in the complex lignocellulosic biomass [41]. This has also been reported in cases of microbial communities, either in autochthonous niches or in defined co-cultures [42].…”

“…There were no isolated microorganisms with important productions of various enzymatic activities. In most of the evaluated substrates, when an isolate presented high values of catalytic activity, at the same time, it showed poor or no activity against other polymers, except for xylanolytic microorganisms, which present high cellulolytic activity [41]. Based on these results, there was not an enzymatic "superproducer" microorganism in the samples analysed, but in the microbial community, there was a marked "enzymatic work specialization", where the degradations of the different substrates were differentiated between species and even between genera.…”