What does this equation mean?

The cost consequences follow directly from that ceiling. Humbird’s fed-batch process model, built around bioreactors at or below the 20-cubic-meter limit, converges on roughly thirty-seven dollars per kilogram of wet cell mass at the largest realistic production scale he models; a perfusion-based alternative converges on roughly fifty-one dollars per kilogram. At the very largest theoretical volumes he considers, and only by essentially eliminating growth-medium cost — a change he treats as necessary but explicitly insufficient on its own — the model’s absolute floor comes down to approximately sixteen dollars per kilogram. Growth medium, chiefly the amino acids that feed the cells, is the dominant line item: at a modeled scale of 100 kilotonnes of annual production, macronutrients alone account for roughly 51% of total fed-batch cost. Humbird models individual amino-acid prices as falling with production volume along a fitted relationship, $\log_{10}(P) = -0.563\,\log_{10}(V) + 3.65$. where P is price in dollars per kilogram and V is production volume in metric tons per year — a real economy-of-scale effect, but one that only partially offsets the bioreactor ceiling above it. His own summary conclusion is that “metabolic efficiency enhancements and the development of low-cost media from plant hydrolysates are both necessary but insufficient conditions for displacement of conventional meat by cultured meat” [ 13 ] — necessary and insufficient, not impossible, which is a materially different claim than the industry sometimes attributes to him in rebuttal.