A method of enhancing the antimicrobial properties of a bacterial strain, comprising cultivation of the bacterial strain in a medium comprising water, at least one component chosen from bee pollen, pollen, and bee bread, and optionally honey and/or nectar is described. The bacterial strain has the ability to be viable for at least 8 days in a 65% by weight sugar solution, preferably at least 8 days in a 70% by weight sugar solution.