Selection of a L-Lysine-Overproducing Strain of the Red Seaweed Porphyra suborbiculata (Rhodophyta) through Mutation and Analog Enrichment

An improved strain of the red seaweed Porphyra suborbiculata containing an increased amount of the essential amino acid llysine was obtained through mutation and analog enrichment. Mutagenesis using a 10% lethal dose of ultraviolet irradiation and an enrichment culture with the l-lysine analog aminoethyl-l-cysteine (AEC) was repeated to select the most productive strain using monospores of P. suborbiculata. The concentrations of AEC required to produce 50 and 100% inhibition of survival were 60and 115 mM in the parent strain, and 72 and 135 mM in the selected AEC-resistant strain, respectively. The AEC-resistant strain,L130, produced 1.74-fold more lysine compared to its parent strain. Thus, mutagenesis with analog enrichment shows promise for selecting seaweed strains that can overproduce this essential amino acid. KCI Citation Count: 0