Tetrahymena thermophila protozoa have a minimum doubling time of 6.5 hours when grown using bacteria as the limiting substrate. the yield of protozoal biomass is 0.33 g per g of bacteria and the substrate constant is 12 mg i^-1. the protozoa are cultured at steady state in a chemostat using a feed stream containing 10 g i^-1 of nonviable bacteria.

(a) what is the maximum dilution rate for operation of the chemostat?
(b) what is the concentration of t. thermophila when the operating dilution rate is one-half of the maximum?
(c) what is the concentration of bacteria when the dilution rate is three-quarters of the maximum?
(d) what is the biomass productivity when the dilution rate is one-third of the maximum?