To moisten by sprinkling; still so used in breweries.
In microbiology, maybe the opposite? "Zafiriou et al. (1989) has demonstrated that in a very low density cell suspension, highly sparged to remove gaseous products..."
The suspension is being sprinkled, not to moisten something else but to maximize gaseous diffusion? I can see that you might use exactly the same equipment as the brewers, but the point of the operation is rather different. And there are online references to bubble-sparged photobioreactors, which seem farther yet from the original dewy sense.
"sperge" is Latin for sprinkle, leading to "asperges" and "aspergillum" for brushes (?!) used to sprinkle holy water in the Roman Catholic church; and from there, to the look-alike fungal species Aspergillum and probably to the family name of the doctor who described Asperger's syndrome. I can't come up with a good back-formation to name the syndrome for sprinkling, or brushes, or even fungi.