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.
So wrote clew in Word.