Abiostress resistance and cellulose degradation abilities of haloalkaliphilic fungi: applications for saline-alkaline remediation

Extremophiles. 2018 Mar;22(2):155-164. doi: 10.1007/s00792-017-0986-3. Epub 2017 Dec 30.

Abstract

Soda saline-alkaline lands are significantly harmful to agriculture; thus, effective strategies to remediate such soil are urgently needed. Multiple negative factors exist in the community structure of saline-alkaline fields, among which the lack of fungal species diversity remains the most prominent problem. The haloalkaliphilic fungi are a unique group of extremophiles that grow optimally under conditions of extreme salinity and alkalinity; these fungi, which buffer salinity and alkalinity by absorbing and/or constraining salt ions, produce organic acids and/or macromolecules, secrete macromolecules such as cellulose degradation enzymes, and provide biomass that is beneficial for soil health. Considering that haloalkaliphilic fungi are a valuable genetic resource of resistance and degradation genes, these fungi are expected to be applied in biotechnology. Aspergillus glaucus exhibits high resistance to a variety of stressors and the ability to degrade crop straw; and it is a practical genetic tool that can be used to identify and validate genes involved in abiotic stress resistance and cellulose decomposition genes. This review will focus on the following aspects: isolation of extreme haloalkaliphilic fungi, fungal genes involved in salt and alkalinity resistance, macromolecule degrading enzymes, applications for genetic improvement of haloalkaliphilic fungi, and application of haloalkaliphilic fungi in saline-alkali soil mycoremediation.

Keywords: Abiostress-resistant gene; Cellulase gene; Haloalkaliphilic fungi; Saline–alkaline remediation.

Publication types

  • Review

MeSH terms

  • Alkalies / metabolism
  • Aspergillus / genetics
  • Aspergillus / metabolism*
  • Biodegradation, Environmental
  • Cellulose / metabolism*
  • Salinity*
  • Stress, Physiological*

Substances

  • Alkalies
  • Cellulose