Maybe… the undispersed 0.4% whould have to stick somewhere and, depending on manufacturing process, can either be lost (to the wall of the water vessel) of get incorporated properly into the product during emulsification.
The problem with Naticide is that nobody except Synerga know what it actually is. Could be a very good or very poor preservative, could be a scam and a pile of lies, could be adulterated with whatever preservatives like several other ‘natural’ preservatives on the market… As long as I don’t see proper, independent data and know what’s really inside, I wouldn’t trust such a ‘preservative’, let alone use it as sole preservative. You can’t really adjust production processes when you don’t know what you’re using.
Which bacteria did they find? Maybe add a second preservative which is strong against these

.
Thank you very much for your response
The bacteria they found are Candida albicans and Aspergillus brasiliensis.