An Insight Into Ameliorating Production, Catalytic Efficiency, Thermostability and Starch Saccharification of Acid-Stable α-Amylases From Acidophiles.

Deepak Parashar,Tulasi Satyanarayana

doi:10.3389/fbioe.2018.00125

Abstract

Most of the extracellular enzymes of acidophilic bacteria and archaea are stable at acidic pH with a relatively high thermostability. There is, however, a dearth of information on their acid stability. Although several theories have been postulated, the adaptation of acidophilic proteins to low pH has not been explained convincingly. This review highlights recent developments in understanding the structure and biochemical characteristics, and production of acid-stable and calcium-independent α-amylases by acidophilic bacteria with special reference to that of Bacillus acidicola.

Highlights

Enzyme characteristics such as thermostability, selectivity, solvent tolerance and substrate affinity can be improved through genetic engineering based on the availability of large data on improving these characteristics (Verma and Satyanarayana, 2012; Widersten, 2014; Joshi and Satyanarayana, 2015)
The majority of the enzymes used at commercial scale lack adequate acid stability, limiting their applications
In order to overcome these problems, microbes that are capable of tolerating harsh conditions could be exploited for naturally tailored enzymes that are superior to their neutrophililic counterparts for utility under harsh bioprocess conditions (Hough and Danson, 1999; Eichler, 2001; Sharma et al, 2012; Raddadi et al, 2015)

Summary

Introduction

Enzyme characteristics such as thermostability, selectivity, solvent tolerance and substrate affinity can be improved through genetic engineering based on the availability of large data on improving these characteristics (Verma and Satyanarayana, 2012; Widersten, 2014; Joshi and Satyanarayana, 2015). Several acidophilic microbes have been reported (Table 1), a very few acid-stable amylases have been studied in adequate detail (Matzke et al, 1997; Sharma et al, 2012). The enzyme is a homodimer with a subunit molecular mass of 66 kDa. Recently a Ca2+-independent, acid-stable α-amylase (Baamy) from the acidophilic bacterium Bacillus acidicola TSAS1 has been investigated in detail.

Results

Conclusion