Large-scale analysis of the genome of the rare alkaline-halophilic Stachybotrys microspora reveals 46 cellulase genes.

ABSTRACT

Fungi are of great importance in biotechnology, for example in the production of enzymes and metabolites. The main goal of this study was to obtain a high-coverage draft of the Stachybotrys microspora genome and to annotate and analyze the genome sequence data. The rare fungus S. microspora N1 strain is distinguished by its ability to grow in an alkaline halophilic environment and to efficiently secrete cellulolytic enzymes. Here we report the draft genome sequence composed of 3715 contigs, a genome size of 35 343 854 bp, with a GC content of 53.31% and a coverage around 20.5×. The identification of cellulolytic genes and of their corresponding functions was carried out through analysis and annotation of the whole genome sequence. Forty-six cellulases were identified using the fungicompanion bioinformatic tool. Interestingly, an S. microspora endoglucanase selected from those with a low isoelectric point was predicted to have a halophilic profile and share significant homology with a well-known bacterial halophilic cellulase. These results confirm previous biochemical studies revealing a halophilic character, which is a very rare feature among fungal cellulases. All these properties suggest that cellulases of S. microspora may have potential for use in the biofuel, textile, and detergent industries.