Aspergillus jilinensis sp. nov. And its thermostable alkaline enzymes evaluation

Abstract

Aspergillus comprises a diverse group of species, which have a ubiquitous distribution and occur on decaying vegetation, soil, and dust. During an investigation of the diversity of alkali-tolerant or alkalophilic fungi in China, two isolates producing columnar conidial heads with globose conidia belonging to Aspergillus were isolated from the soda soil and named as Aspergillus jilinensis. Its phylogenetic position was determined by analysis of a dataset of the combined gene fragments including the nuclear ribosomal internal transcribed spacer region, beta-tubulin, and calmodulin genes. The morphology and culture characteristics of this fungus were described. Distinctions between the new species and its close relatives were discussed. Aspergillus jilinensis was phylogenetically clustered with A. alabamensis, but it differed from the latter by producing smaller and fewer conidia. Additionally, colonies of A. jilinensis presented light buff-colored on malt extract agar and bright golden yellow color on Czapek yeast autolysate. Meanwhile, the enzyme activity assays showed that α-amylase, endo-protease, and endo-β-1, 4-xylanase of A. jilinensis were thermostable in an alkaline reaction system, responding to alkali-tolerant characteristics, indicating a potential alkali-tolerant enzyme candidate. This study updates our knowledge of species diversity of alkali-tolerant Aspergillus.