A strain with 2 g/L yield of poly-ε-lysine was firstly screened from soil on an agar plate containing methylene blue and then further selected by a flask experiment. The strain was preliminarily identified as Streptomyces albulus. The experiment about medium optimization showed that glucose was the best carbon sources and yeast extract and (NH4)2SO4 were the best compound nitrogen sources. The yield of ε-PL reached 3.9 g/L with optimal medium.
