Year: 2015
Type: article
Abstract: In this study, site-directed mutagenesis was carried out to alter properties of Mucor pusillus rennet (MPR) in order to find a potential substitution of commercial chymosin. Mutant G186D/E13D screened from thousands of mutants showed a significant milk-clotting activity (MCA). Mutant G186D/E13D rennet was purified and characterized. The molecular weight was estimated to be 44 kDa by SDS-PAGE. The maximum enzyme activity was at a wide range of pH (5.0-7.0) and 60ºC. The enzyme was inhibited by metal ions (Fe2+, Fe3+, Cu+ and Zn2+), 1.10-Phenantrolin and pepstatin A. Further texture analysis of types of cheddar cheese made by non-mutant rennet, mutant (G186D/E13D) rennet and commercial rennet suggested that the soluble nitrogen content and hardness of cheddar cheese made by chimeric mutant rennet was decreased without any significant change in flavor between these cheeses. The result implicated that, to some extent, the mutant rennet could decrease hydrolysis of protein during ripening of cheese, probably as a candidate for a useful milk coagulant.
Source: The Open Biotechnology Journal
Authors: Li Yuqiu, Tan Hua, Li Da, Li Zhoulin, Chi Yanping, Jiang Yuanyuan, Liu Xiangying, Wang Jinghui, Li Qiyun
Institution: Jilin Academy of Agricultural Sciences
Language: English
Subfield: Biotechnology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: diamond
OpenAlex ID: W1750753829