Catalyzes the ATP-dependent phosphorylation of fructose-l-phosphate to fructose-l,6-bisphosphate. Involved in the utilization of fructose as a sole carbon and energy source. ATP + beta-D-fructose 1-phosphate = ADP + beta-D-fructose 1,6-bisphosphate + H(+) Optimum pH is between 7.5 and 9. Homodimer. Expression is highly up-regulated in presence of fructose. Loss of growth on fructose. Growth on glucose is not affected. Belongs to the carbohydrate kinase PfkB family.