Whole Foods Market has announced plans to celebrate the opening of its store at 808 Massachusetts Ave. with a “bread-breaking” ceremony at 9:45 a.m. Sept. 18 . The new grocery will be the Texas-based chain’s 28th location in Massachusetts, and will have 115 full and part-time employees. Johnnie’s Foodmaster occupied the space until last fall. The new supermarket will carry groceries, produce, seafood, and meats. It will also have a pizza station, and a noodle and dumpling bar. The store will be open from 8 a.m. to 10 p.m. seven days a week.