Phenotype Switching in Metal-Tolerant Bacteria Isolated from a Hyperaccumulator Plant

• Main Authors: Artur Banach, Agnieszka Kuźniar, Anna Marzec-Grządziel, Anna Gałązka, Agnieszka Wolińska
• Format: Article
• Language: English
• Published: MDPI AG 2021-09-01
• Series: Biology
• Subjects: <i>Azolla</i>; heavy metals; hydrolytic enzymes; IAA; microbiome; organic pollutants
• Online Access: https://www.mdpi.com/2079-7737/10/9/879

As an adaptation to unfavorable conditions, microorganisms may represent different phenotypes. <i>Azolla filiculoides</i> L. is a hyperaccumulator of pollutants, but the functions of its microbiome have not been well recognized to date. We aimed to reveal the potential of the microbiome for degradation of organic compounds, as well as its potential to promote plant growth in the presence of heavy metals. We applied the Biolog^TM Phenotypic Microarrays platform to study the potential of the microbiome for the degradation of 96 carbon compounds and stress factors and assayed the hydrolytic potential and auxin production by the microorganisms in the presence of Pb, Cd, Cr (VI), Ni, Ag, and Au. We found various phenotype changes depending on the stress factor, suggesting a possible dual function of the studied microorganisms, i.e., in bioremediation and as a biofertilizer for plant growth promotion. <i>Delftia</i> sp., <i>Staphylococcus</i> sp. and <i>Microbacterium</i> sp. exhibited high efficacy in metabolizing organic compounds. <i>Delftia</i> sp., <i>Achromobacter</i> sp. and <i>Agrobacterium</i> sp. were efficient in enzymatic responses and were characterized by metal tolerant. Since each strain exhibited individual phenotype changes due to the studied stresses, they may all be beneficial as both biofertilizers and bioremediation agents, especially when combined in one biopreparation.