This chapter discusses the taxonomy of non-Bacillus and Pseudomonas (NBP) bioprotectant strains, including enterobacteria, actinomycetes, Sphingomonas, Methylobacterium, Agrobacterium-Rhizobium and Lactobacillus. The chapter reviews their mechanisms of action against plant pathogens. Sources of isolates and methods of isolation are discussed in building strain collections. The chapter then reviews procedures for screening antagonistic bacteria candidates as bioprotectants using biochemical and molecular markers, including the example of lactic acid bacteria. The chapter then covers strain improvement to increase fitness and efficacy in the field through physiological and genetic manipulation. Since they are essential for commercial development, biosafety issues are discussed, followed by an overview of patented substances and commercialized products. The chapter concludes with a summary and future trends in research on non-Bacillus and Pseudomonas species.