Abstract
With the invasion of green tides and the increase of urban green areas worldwide, multimillion tons of Enteromorpha need to be reutilized. In this study, Enteromorpha prolifera powder is considered a promising biomass resource for the production of commercial chemical products production. Ilamycins, novel cyclic heptapeptides with significant anti-TB activities, are isolated from Streptomyces atratus SCSIO ZH16, a deep-sea-derived strain. Using EP powder as a nitrogen source, the production of ilamycins reached 709.97 mg/L through optimization of the nitrogen source using the engineered strain S. atratus SCSIO ZH16 ΔR. After mutant strain constructions and tests, strain S. atratus SCSIO ZH16 ΔR::bldD EP powder achieved a higher production titer of ilamycins. Furthermore, the production titer of ilamycins and ilamycin E reached 1561.77 mg/L and 745.44 mg/L, respectively, in a 5 L bioreactor. This study suggests that E. prolifera is a promising and eco-friendly nitrogen source for the production of ilamycins.