What is bromelain?
Bromelain is a group of thiol hydrolytic proteases extracted from the tropical plant pineapple. Bromelain which belongs to the papain family of cysteine proteases mainly exists in the fruit, bud, leaf and stem of pineapple. Bromelain has a variety of properties, including anti-cancer activity, anti-inflammatory effect, antimicrobial effect, antibiotic potentiation, skin protection, postsurgery recovery and so on. Therefore, it has a wide range of applications in the medical and food fields.
Traditional production technology
The traditional production technology has the problems of high cost, low enzyme activity and low yield for taking pineapple as raw material. In addition to low production efficiency, it also brings issues of environmental pollution and resource waste.
Bromelain in feed processing
Bromelain can improve the conversion rate of feed and also has a certain the rapeutic effect on diarrhea caused by pathogenic bacteria as antibiotic subtitution. In a word, it is beneficial to the growth and health of farmed animals.
Local problem
China is a big agricultural country, and breeding industry is an important branch of agriculture. In the shortage of protein feed resources and the low efficiency of animal protein utilization in China, bromelain undoubtedly has a very rich application potential. However, the complexity and difficulty of the traditional production process hinder its further development and application.
Solution
We hope to use the engineered Bacillus subtilis to heterogeneously express bromelain, so as to ameliorate the traditional production methods. And the purpose for our study is to improve both enzymatic activity and stability via semi-rational directed evolution.