Evaluation of new xylanolytic-producing isolates of Aspergillus from Misiones subtropical rainforest using sugarcane bagasse

DÍAZ, GABRIELA VERÓNICA; ZAPATA, PEDRO DARÍO; VILLALBA, LAURA LIDIA; FONSECA, MARÍA ISABEL

Arab Journal of Basic and Applied Sciences

Taylor & Francis Group

Año: 2019 vol. 26 p. 292 - 301

Xylanases hydrolyse efficiently the xylan component of hemicelluloses into single xylosemonomers. Hence, these enzymes are suitable to be applied in the bioconversion of lignocellulosic wastes such as sugarcane bagasse to improve the bioethanol process. Misionesrainforest in the northeast of Argentina has a huge biodiversity which becomes the mostlikely site to screen new fungal isolates for powerful xylanolytic enzymes. The aim of thiswork was to find efficient xylanolytic Aspergillus with low levels of proteolytic enzymesthrough the isolation and exploration of native fungi from Misiones. Fungi were isolatedfrom different locations of this subtropical region and 25 Aspergillus isolates were screenedbased on their ability to produce xylanolytic and proteolytic enzymes. From the principalcomponent and conglomerate analysis, six groups were discriminated. The most promisingfungi presented the highest endoxylanase and b-xylosidase activities and the lowest proteolytic activities. These isolates were A. niger LBM 055 and A. niger LBM 134 which reached 29and 27 UmL1 of endoxylanases, respectively; 0.6 UmL1 of b-xylosidases, no casein andvery little gelatin proteases. This study proves that the search of new fungi from nature isan important strategy to find novel isolates with the ability to secrete high-performancexylanases and exploit these enzymes in the bioconversion of lignocellulosic wastes