Sunflower stalk as a carbon source inductive for fungal xylanase production

Abstract Enzymes represent a growing market due to their industrial applications, whose use on a large scale is restricted by their high cost of production. This stimulates studies with other sources such as the use of agro-industrial lignocellulosic residues in the medium composition for its production. Thus, in this work, in natura sunflower stalks (Helianthus annuus L.) and its respective alkaline and autohydrolysis pre-treatment liquors were used as carbon sources inducing xylanase production by Aspergillus sp. fermentation. Results showed xylanasic activities of 2.97 and 4.91 U/mL, using alkaline and autohydrolysis liquors, respectively, while the in natura residue displayed the highest value (17.48 U/mL). On the other hand, the in natura sunflower stalk + liquors (alkaline and autohydrolysis, separately) blend significantly improved enzyme production, 6.34 and 11.98 U/mL, compared with the use of each liquor as the sole source inducing. Therefore, sunflower stalks and their liquors are potential inducing sources for the xylanase production, compared with the commercial purified xylan.