Characterization of SdGA, a cold-adapted and salt-tolerant glucoamylase from Saccharophagus degradans.

WAYLLACE, NATAEL M.; HEDÍN, NICOLAS; BUSI, MARIA VICTORIA; DIEGO FABIAN GOMEZ CASATI

Virtual

Congreso; 3er. Encuentro & 1er. Workshop, Red Argentina de Tecnología Enzimática (RedTez).; 2021

RedTez

Saccharophagus degradans is a gram-negative marinebacterium. It is the most versatile bacterium in terms of the degradation ofcomplex polymers (CP) found to date. It is capable to degrade at least 10complex polymers such as starch, agar, laminarin, cellulose, pectin, alginate,chitin, fucoidan, pectin, pullulan, and xylan at high rate. The objective ofthis work is to carry out the structural characterization and functionalproperties of SdGA, a novel glucoamylase (GA) from S. degradans. The enzyme is composed mainly of a N-terminal GH15_Ndomain linked to a C-terminal catalytic domain (CD) found in the GH15 family ofglycosylhydrolases with an overall structure similar to other bacterial GAs.The protein was successfully expressed in Escherichiacoli cells, purified and its biochemical properties were investigated. SdGAshowed maximum activity at 39°C and pH 6.0. The enzyme has high activity in awide range, from low to mild temperatures, like cold-adapted enzymes. It showedthe same maximum activity in the range of 0 – 1.0 M NaCl like salt-tolerantamylases. Furthermore, SdGA has a larger CD due to various amino acidinsertions and a higher content of flexible residues compared to other thermostableGAs. We propose that this novel SdGA, is a salt-tolerant and cold-adapted enzymethat might be suitable for use in different industrial processes that requireenzymes which act at low or medium temperatures.