The sea bass that were fed the alternative microbe protein diet did have significantly lower weight to begin with, but that evened out as they grew. And, notably, the group that received the traditional feed diet had greater variability in their weight gain as they grew—whereas those fed the alternative microbe protein diet showed a more even accumulation of weight over the experiment’s course.

Meanwhile, the wastewater from other soybean uses goes unused—but according to the recent results, could feasibly tackle both of these sustainability challenges at once. Furthermore it’s not just soybean waste water, the researchers say: several agricultural processes create wastewater side streams that are rich in the combination of carbon, nitrogen, and phosphorus that’s needed to sustain a growing population of hungry, protein-accumulating bacteria.

Microbial community‐based protein from soybean‐processing wastewater as a sustainable alternative fish feed ingredient.