Fungi in acidic fire: A potential source of industrially important enzymes

The microbial life that exists in harsh habitats of low pH possess several unique characteristics, which assign interesting qualities to these microorganisms and enable them to thrive in such a harsh environment. Among microorganisms inhabiting low pH environments, fungi are the second largest reported organisms. These acidophilic fungi are the main source of acid–stable enzymes that could be utilized in many industries including paper, leather making, food and feed industries, where the efficacy of commonly available enzymes is limited by challenges like stability and functional kinetics. The current review discusses the acidophilic fungi with emphasis on their diversity and pH homeostasis mechanisms adopted against low pH environments. In addition, an overview about the acid–stable enzymes obtained from these acidophilic fungi, their main sources and potential applications have also been discussed.