The use of bacteria-based binders to bind and strengthen 3D printed compositions; bio-plastic 3D printing materials comprised of combinations of particles of organic substrates such as coffee, pistachio shells and coconut shells, as well as sand (and combinations of one or more of the foregoing); processes for creating scent-free bio-plastic 3D printing material and products from such particles; the application of a copper finish, chrome finish and powder finish to bio-plastics made from such particles; and products and fixtures, such as sinks, toilets, faucets, coffee mug molds, lighting fixtures, and coffee cups, comprising non-flammable bio-plastic created by a process of 3D printing from such particles. Processes for imparting color or structure or surface texture to these and binding and strengthening them using enzyme-secreting bacteria.