The present invention is directed to a microbial inoculant that is effective for preventing cold stress. In an important aspect of the invention, the microbial inoculant includes the Azospirillum brasilense, Bacillus subtilis, Bacillus megaterium, Lactocoecus spp., Pseudomonas sp, Pseudomonas putita, Pseudomonas lurida, Acinetobacter, Paenibacillus sp, Burkholderia phytofirmans. The use of those as a microbial inoculant is effective for increasing the productivity of both nonlegume and legume plants as well as vegetable plants over a wide variety of soil types and climates. One important aspect of the invention is directed to biologically pure cultures of Azospirillum brasilense, Bacillus subtilis, Bacillus megaterium, Lactocoecus spp., Pseudomonas sp, Pseudomonas putita, Pseudomonas lurida, Acinetobacter, Paenibacillus sp, Burkholderia phytofirmans. Azospirillum brasilense, Bacillus subtilis, Bacillus megaterium, Lactocoecus spp., Pseudomonas sp, Pseudomonas putita, Pseudomonas lurida, Acinetobacter, Paenibacillus sp, Burkholderia phytofirmans, may be used as a microbial inoculant either alone or in combination with other agronomically beneficial microorganisms. Application of the microbial inoculant to the plant or the soil prevent cold stress, provides an increased level of soil nitrogen, improves mineral uptake into plants, stimulates plant growth through the production of plant growth regulators, and inhibits phytopathogenic microflora. In another important aspect, the present invention provides a method for growing Azospirillum brasilense, Bacillus subtilis, Bacillus megaterium, Lactocoecus spp., Pseudomonas sp, Pseudomonas putita, Pseudomonas lurida, Acinetobacter, Paenibacillus sp, Burkholderia phytofirmans. In accordance with the method of the invention, Azospirillum brasilense, Bacillus subtilis, Bacillus megaterium, Lactocoecus spp., Pseudomonas sp, Pseudomonas putita, Pseudomonas lurida, Acinetobacter, Paenibacillus sp, Burkholderia phytofirmans is inocu
