Both groups you mentioned are extremely diverse in terms of their physiology and genetic features. As for the IB, the principal negative effects of their growth are
related with the corrosion of water pumps pressure tanks, galvanized pipes and fittings; the clogging of metal and plastic pipes; the reduction of water flow and water pressure and the coating of the resin beds of water softeners with slime.(have in mind that the iron bacteria are in general very resistant to chemical methods
of control, perhaps due to the protective slime layers and other coatings which surround the cells,together with the tendency for the cells to clump and/or form thick layers.)
Best regards!
P.S.
DONDERO, N. C. 1975 The Sphaerorilus-Leptuthrix group. Annual Review of Microbiology 29. 407-428
AVERY, E. L. 1970 Effects of domestic sewage on aquatic insects and salmonids of the East Gallatin River. Montana. Water