Proteomic Analysis of the Secretome of Cellulomonas fimi ATCC 484 and Cellulomonas flavigena ATCC 482.

Warren W Wakarchuk,Denis Brochu,John Kelly,Simon Foote,Tamara Erak,Hirak Saxena,Anna Robotham,Kyoung Heon Kim

doi:10.1371/journal.pone.0151186

Warren W Wakarchuk, Denis Brochu + Show 6 more

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https://doi.org/10.1371/journal.pone.0151186

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Abstract

The bacteria in the genus Cellulomonas are known for their ability to degrade plant cell wall biomass. Cellulomonas fimi ATCC 484 and C. flavigena ATCC 482 have been the subject of much research into secreted cellulases and hemicellulases. Recently the genome sequences of both C. fimi ATCC 484 and C. flavigena ATCC 482 were published, and a genome comparison has revealed their full spectrum of possible carbohydrate-active enzymes (CAZymes). Using mass spectrometry, we have compared the proteins secreted by C. fimi and C. flavigena during growth on the soluble cellulose substrate, carboxymethylcellulose (CMC), as well as a soluble xylan fraction. Many known C. fimi CAZymes were detected, which validated our analysis, as were a number of new CAZymes and other proteins that, though identified in the genome, have not previously been observed in the secretome of either organism. Our data also shows that many of these are co-expressed on growth of either CMC or xylan. This analysis provides a new perspective on Cellulomonas enzymes and provides many new CAZyme targets for characterization.

Highlights

Strains of the Cellulomonas genus were shown almost 40 years ago to produce extracellular enzymes that could efficiently degrade pretreated sugarcane bagasse [1]
We compared the genomes of four actinobacteria (C. fimi (CFi), C. flavigena CFl), S. coelicolor (SC) and
In the work presented here the accounting for the predicted carbohydrate-active enzymes (CAZymes) certainly shows significant CAZyme expression from both strains including most of the predicted cellulase and xylanase including all of the predicted AA10 enzymes which are most beneficial for utilization of insoluble substrates

Summary

Introduction

Strains of the Cellulomonas genus were shown almost 40 years ago to produce extracellular enzymes that could efficiently degrade pretreated sugarcane bagasse [1]. In order to make sense of these multi-enzyme systems for biomass degradation, it is important to understand under what conditions and with what kind of induction and regulation are different subsets of CAZymes expressed. The secretome of both T. fusca and a Streptomyces species have been examined by modern proteomics techniques [17, 18], but to date, no similar analysis of the secretome of Cellulomonas species has been completed. We show here that expression of many of these proteins appears to be dependent on the growth medium (CMC or xylan)

Material and Methods

Results and Discussion

Conclusions