Enlargement of Deinococcus grandis spheroplasts requires Mg or Ca.

While the cell wall strictly controls cell size and morphology in bacteria, spheroplasts lack cell walls and can become enlarged in growth medium under optimal conditions. Optimal conditions depend on the bacterial species. We frequently observed extreme enlargement of spheroplasts of the radiation-resistant bacterium Deinococcus grandis in Difco Marine Broth 2216, but not in TGY broth (a commonly used growth medium for Deinococcus).

Some observations on the structure and function of the spinning apparatus in the silkworm Bombyx mori.

Silkworm silk has outstanding mechanical properties despite being spun at room temperature and from aqueous solution. Although it has been proposed that fiber formation is mainly induced by shearing and extensional flow in the spinneret, the detailed structure and function of the spinning apparatus of Bombyx mori silkworms are still not fully elucidated. In this paper we describe three aspects of the functional microanatomy of the spinning apparatus: changes in the diameter of the silk gland duct with distance along the duct, how the birefringence of the fibroin changes as it flows down the duct, and the detailed three-dimensional structure of the silk press and related structures.