Valentino Setoa Junior Te'o

Making a Bacterial Thermophilic Enzyme in a Fungal Expression System

This unit describes production of a bacterial thermophilic xylanase enzyme in an industrially exploited filamentous fungus, Trichoderma reesei. Successful expression of a gene of interest in a heterologous host involves front‐end design of the expression constructs using bioinformatics tools, making the constructs in the laboratory, and introducing them into the expression host. This is followed by synthesis and characterization of the gene product on a laboratory scale and optimization of the cultivation parameters in a controlled, scaled‐up fermentation. The thermophilic xylanase B (XynB) enzyme from the bacterium Dictyoglomus thermophilum discussed here can be easily purified by heat‐precipitation from the culture supernatant of the mesophilic host. A functional XynB can also be produced in Escherichia coli, but at a lower yield compared to that obtained in T. reesei. The protocol provided here can be adapted to various other proteins and filamentous fungal hosts.

Draft Genome Sequence of Caloramator mitchellensis, a Thermoanaerobe Isolated from the Waters of the Great Artesian Basin

ABSTRACT The genome sequence of Caloramator mitchellensis strain VF08, a rod-shaped, heterotrophic, strictly anaerobic bacterium isolated from the free-flowing waters of a Great Artesian Basin (GAB) bore well located in Mitchell, an outback Queensland town in Australia, is reported here. The analysis of the 2.42-Mb genome sequence indicates that the attributes of the genome are consistent with its physiological and phenotypic traits.