The mechanisms by which nutrients traverse the Mycobacterium tuberculosis (Mtb) outer membrane remain mostly unknown and. in the absence of classical porins. likely involve specialized transport systems. Calcium ions (Ca2+) are an important nutrient and serve as a second messenger in eukaryotes. https://www.bekindtopets.com/super-value-Blue-Lotion-Topical-Antiseptic-16-oz-flash-save/