Acidophilic fungal beta-glucosidase(s) for biorefinery applications
Typ
Examensarbete på grundnivå
Program
Kemiteknik 180 hp (högskoleingenjör)
Publicerad
2024
Författare
Danielsson, Albin
Wray, Ingrid
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Lignocellulose is a promising substrate for the production of chemicals and materials. In
traditional biorefineries, it is first pretreated to disrupt its structure, thereby yielding acidic
fractions. Therefore, enzymes from acid-tolerant organisms would be advantageous for their
bioconversion. In this study, we have investigated beta-glucosidases (BGLs) from the fungi
Talaromyces sp1. ASS 358-9 (Talaromyces-358), which thrives in highly acidic conditions and
can utilize inhibitor-rich liquor from spruce pretreatment for growth and enzyme production.
Since BGLs are crucial for biomass saccharification, we are studying the properties of
differentially expressed Talaromyces-358 BGLs, aiming to find robust enzymes for biorefinery
use that can withstand harsh environments like high temperatures and low pH levels. Culturing
Talaromyces-358 in various liquid media revealed glucose as the most favorable substrate,
significantly enhancing BGL activity over 15 days, while spruce liquor, though initially
inhibitory, eventually supported significant enzyme production. The BGLs exhibited peak
activity at 80°C and maintained considerable activity at 90°C, with optimal pH ranging from 4
to 6, demonstrating adaptability to harsh conditions. Enzyme activity was measured using
substrates such as glucose, glucose-spruce, spruce, xylan, and xylan-spruce, with
temperature measurements taken from 30°C to 90°C at pH 4, and pH measurements taken
from 2 to 9 at 50°C. However, there was little to no BGL activity observed at neutral and basic
pH levels.
Beskrivning
Ämne/nyckelord
Beta-glucosidase (BGL) , Talaromyces sp. ASS 358-9 (Talaromyces-358) , Enzyme activity , Thermal stability , pH dependence , Substrate specificity , Lignocellulose bioconversion , Biorefineries