Efficacy and safety profile of a subtilisin protease produced by fermentation in Bacillus licheniformis to be used as a feed additive

Abstract

The efficacy and safety of a novel Subtilisin protease from a Bacillus sp. produced in Bacillus licheniformis was investigated in broiler chickens, and a range of toxicological tests, respectively. The B. licheniformis production strain culture supernatant was not found cytotoxic in a Vero cell assay. Subtilisin was non-mutagenic and non-clastogenic in in-vitro tests, and did not exhibit irritating potential to the eye or skin in ex-vivo/in-vitro models. Oral administration of Subtilisin to rats did not cause any adverse effects in a 13-week sub-chronic toxicity study. In addition, a 35-day dose response broiler performance trial conducted with Subtilisin (30,000 and 60,000 NFP/kg diet), showed a significant linear improvement in both body weight gain and feed conversion ratio up to 35 days of protease supplementation.In conclusion, there are no safety concerns using this novel Subtilisin as a feed additive, and the protease is efficient in improving broiler growth performance, making it a good candidate for use as a feed additive.

Keywords

• Subtilisin
• Bacillus licheniformis
• Toxicity
• Safety
• Feed additive
• Broiler chickens