Six Gram-stain-positive and rod-shaped strains, designated FJAT-51614T, FJAT-51639T, FJAT-52054T, FJAT-52991T, FJAT-53654T and FJAT-53711T, were isolated from a mangrove ecosystem. The condition for growth among the strains varied (pH ranging 5.0–11.0 and temperature 15–45 °C). These strains showed the highest 16S rRNA gene sequence similarity to the genera Bacillus, Metabacillus and Psychrobacillus. Menaquinone MK-7 (100%) was present in all strains except strain FJAT-51614T, which contained MK-7 (32%) and MK-8 (68%). The major fatty acids (>10%) in strains FJAT-52054T and FJAT-51614T were anteiso-C15: 0 and iso-C14: 0. The major fatty acid (>10%) in strain FJAT-53654T was anteiso-C15: 0, while in strain FJAT-51639T were iso-C15: 0 and iso-C17: 0. The major fatty acids in strains FJAT-52991T and FJAT-53711T were iso-C15: 0 and iso-C16: 0. The major polar lipids in strains FJAT-51639T, FJAT-52991T and FJAT-51614T were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine, while strains FJAT-53711T, FJAT-52054T and FJAT-53654T consist of diphosphatidylglycerol and phosphatidylglycerol. The genome-relatedness values among the present study strains and the closest species were below the recognized cutoff levels for species deline-ation. The polyphasic analysis comparison results represent six strains as novel species for which the names Bacillus bruguierae sp. nov. (FJAT-51639T =GDMCC 1.3073T =JCM 35615T), Bacillus kandeliae sp. nov. (FJAT-52991T =GDMCC 1.3069T =JCM 35619T), Bacillus yunxiaonensis sp. nov. (FJAT-53711T =GDMCC 1.3068T =JCM 35616T), Metabacillus rhizos-phaerae sp. nov. (FJAT-53654T =GDMCC 1.3075T =JCM 35614T), Metabacillus sediminis sp. nov. (FJAT-52054T =GDMCC 1.3074T =JCM 35620T) and Psychrobacillus mangrovi sp. nov. (FJAT-51614T =GDMCC 1.3072T =JCM35478T) are proposed.