Directed evolution for soluble and active periplasmic expression of bovine enterokinase in Escherichia coli.

Bovine enterokinase light chain (EK) is an industrially useful protease for accurate removal of affinity-purification tags from high-value biopharmaceuticals. However, recombinant expression in Escherichia coli produces insoluble inclusion bodies, requiring solubilisation, refolding, and autocatalytic activation to recover functional enzyme. Error-prone PCR and DNA shuffling of the EK gene, T7 promoter, lac operon, ribosome binding site, and pelB leader sequence, yielded 321 unique variants after screening ~ 6500 colonies.

Safety Evaluation of a Novel Algal Feed Additive for Poultry Production.

Feed additives are critical components for poultry health and the economic viability of antibiotic-free poultry production. The aim of the present study is to evaluate the safety of a novel algal-derived feed additive, a dried biomass powder produced from strain crAL082, modified to express an N-acetylmuramoyl-L-alanine amidase (EC 3.5.