Safety assessment of Synechococcus sp. PCC 7002 biomass: genotoxicity, acute and subchronic toxicity studies

Synechococcus sp. PCC 7002 has the potential to be used as a new resource of food owing to its nutritional and functional benefits. However, little information has been published regarding the safety of Synechococcus sp. PCC 7002 biomass (SynB). The present study assessed genotoxicity, acute and subchronic toxicity of SynB for the first time. SynB did not show any genotoxicity based on the Ames test, mammalian erythrocyte micronucleus test, and mouse primary spermatocyte chromosome aberration test. SynB administered by gavage in mice at a dose of 10 g per kg body weight did not induce death or toxicity based on the acute toxicity study, indicating the median lethal dose value of SynB was over 10 g per kg body weight. In the 90-day subchronic toxicity study, no treatment-related mortality or clinical sign was noted with SynB at doses of 5 and 10 g per kg body weight in mice, and there was no adverse effect of SynB on food consumption, organ coefficients, blood biochemistry, urinalysis and histopathology. The Non Observed Adverse Effect Level for SynB in female and male mice was not less than 10 g per kg body weight per day based on subchronic toxicity. These results support the safe use of SynB as a new food raw material.