Ectoine production from putrefactive non-volatile amines in the moderate halophile Halomonas elongata

The moderate halophile Halomonas elongata can assimilate a variety of sugars and/or amino acids derived from bio-wastes as carbon and/or nitrogen sources. Thus, H. elongata could be a practical cell factory for bioproduction of fine chemicals such as ectoine. In protein-rich bio-wastes, putrefactive non-volatile amines could be formed as biogenic amines by decarboxylation of amino acids during biological rotten processes and be a considerable toxicological risk. Therefore, we investigated whether H. elongata can assimilate major putrefactive non-volatile amines, Histamine and Tyramine, as carbon and/or nitrogen sources or not. Comparative analysis using closely related H. elongata strains, OUT30018 and DSM2581T, revealed that H. elongata OUT30018 can assimilate both Histamine and Tyramine, and produce ectoine under high salinity, while H. elongata DSM2581T cannot. Thus, H. elongata OUT30018 would be a one of the most promising cell factories to produce fine chemicals such as ectoine from the putrefactive non-volatile amines in protein-rich bio-waste.