Evolutionary Adaptation as a Tool to Generate Targeted Mutant Strains as Evidence by Increased Inulinase Production in Aspergillus oryzae

Abstract

Genome sequencing has affected studies into the biology of all classes of organisms and this is certainly true for filamentous fungi. The level with which biological systems can be studied since the availability of genomes and post-genomic technologies is beyond what most people could have imagined previously. The fungal genera Aspergillus and Penicillium contain some species that are amongst the most widely used industrial microorganisms and others that are serious pathogens of plants, animals and humans. These genera are also at the forefront of fungal genomics with many genome sequences available and a whole genus genome sequencing project in progress for Aspergillus.This book highlights some of the changes in the studies into these fungi, since the availability of genome sequences. The contributions vary from insights in the taxonomy of these genera, use of genomics for forward genetics and genomic adaptations, to specific stories addressing virulence, carbon starvation, sulphur metabolism, feruloyl esterases, secondary metabolism and pH modulation, to the development of novel methodology for use in parallel to genome sequencing. It therefore provides a taste of the current status of research in Penicillium and Aspergillus and a promise of many more things to come.An essential reference for everyone working with Aspergillus and Penicillium and other filamentous fungi and the book is also recommended reading for everyone with an interest in fungal genomics.

Evolutionary adaptation of Aspergillus niger for increased ferulic acid tolerance

“…Adaptive evolution is a powerful tool, which uses the ability of micro‐organisms to adapt to environmental changes, in order to improve strains for various biotechnological applications (Wallace‐Salinas and Gorwa‐Grauslund ; Culleton et al ; González‐Ramos et al ; Patyshakuliyeva et al ). Most of the current filamentous fungi obtained through adaptive evolution were created for increased enzymatic activity.…”

“…Through an adaptive evolutionary approach, an Aspergillus niger strain with improved cellulase production was created (Patyshakuliyeva et al ). This strategy was also successful for the creation of an Aspergillus oryzae strain with improved inulinase production (Culleton et al ). Moreover, evolutionary adaptation has also been proven to be efficient to obtain industrial micro‐organisms with increased stress tolerance and substrate utilization.…”

Developments and opportunities in fungal strain engineering for the production of novel enzymes and enzyme cocktails for plant biomass degradation

“…Similarly, successive culturing of A. oryzae on agar plates with inulin resulted in significantly improved growth of the progeny (Culleton et al, 2016). Interestingly though, the best mutant did not only display increased inulinase activity, but also several other plant biomass degradation related activities.…”

Strategies for the Development of Industrial Fungal Producing Strains

“…Growth on increasing levels of ferulic acid also resulted in an improved A. niger strain with a higher tolerance to aromatic compounds, which is beneficial for various industrial applications [ 60 ]. Adaptive evolution also improved inulinase production in Aspergillus oryzae [ 61 ]. In Ashbya gossypii ATCC 10895, adaptive evolution enhanced substrate (cane molasses) utilization and increased riboflavin yield.…”