Identification of culturable microbial functional groups isolated from the rhizosphere of four species of mangroves and their biotechnological potential

• Microbial populations are significantly influenced by mangrove species.
• The highest microbial populations were found at the white and black mangroves.
• White mangrove had the highest microbial populations, and better soil properties.
• Mangrove rhizosphere harbors microorganisms for biotechnological applications.

This study identified microbial functional groups like total culturable bacteria, potential N2-fixing free living bacteria, N2-fixing hydrocarbonoclastic bacteria, N-assimilating hydrocarbonoclastic bacteria, total fungi, actinobacteria, P-solubilizers, lipolytic microorganisms, and starch, cellulose, pectin and protein degrading microorganisms, isolated from the rhizosphere of four species of mangroves (Red, Black, White, and Button) from the natural protected area at the Terminos Lagoon, Campeche, México. Overall, microbial populations showed significant differences (P < 0.05) among the four mangrove species. The rhizosphere of White mangrove showed better chemical and textural soil properties, and harbored the highest microbial populations when compared to the remaining mangrove species. The principal component analysis indicated that two components accounted the 85.3% of the total variation. The most significant textural and chemical soil properties were the major components, CP1 (organic matter and total organic carbon) and CP2 (sand and clay). Microbial populations correlated (P < 0.05, Pearson coefficient) with sand and clay particles, and with some soil chemical properties such as organic matter. The total nitrogen and organic carbon significantly correlated with cellulose degraders, while phosphorus with N2-fixing bacteria, total fungi, and with pectin and starch degraders.