Optimization of protease production and sequence analysis of the purified enzyme from the cold adapted yeast Rhodotorula mucilaginosa CBMAI 1528

• Published in: Biotechnology Reports
• Main Authors: Luciana Daniela Lario, Omar Santiago Pillaca-Pullo, Lara Durães Sette, Attilio Converti, Paula Casati, Claudia Spampinato, Adalberto Pessoa
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2020
• Subjects: Antarctic yeast; Aspartic protease; Rodothorulapepsin; Biotechnology; TP248.13-248.65; Antarctic; The Antarctic; Antarc*
• Online Access: https://doi.org/10.1016/j.btre.2020.e00546; https://doaj.org/article/b47b94c32367410c99426138603cf93d

Enzymes from cold-adapted microorganisms are of high interest to industries due to their high activity at low and mild temperatures, which makes them suitable for their use in several processes that either require a supply of exogenous energy or involve the use of heat labile products. In this work, the protease production by the strain Rhodotorula mucilaginosa CBMAI 1528, previously isolated from the Antarctic continent, was optimized, and the purified enzyme analyzed. It was found that protease production was dependent on culture medium composition and growth temperature, being 20 °C and a culture medium containing both glucose and casein peptone (20 and 10 g/L, respectively) the optimal growing conditions in batch as well as in bioreactor. Moreover, mass spectrometry analysis revealed that the enzyme under study has a 100 % sequence identity with the deduced amino acid sequence of a putative aspartic protease from Rhodotorula sp. JG-1b (protein ID: KWU42276.1). This result was confirmed by the decrease of 95 % proteolytic activity by pepstatin A, a specific inhibitor of aspartic proteases. We propose that the enzyme reported here could be Rodothorulapepsin, a protein characterized in 1972 that did not have an associated sequence to date and has been classified as an orphan enzyme.