Application of Psychrotolerant Antarctic Bacteria and Their Metabolites as Efficient Plant Growth Promoting Agents

Abstract

Iron is the fourth most abundant element on earth. However, its low bioavailability is a key plant-growth limiting factor. Bacteria play an important role in plant growth promotion since they produce specific secondary metabolites that may increase macro- and micronutrient accessibility in soil. Therefore, bacterial-derived iron chelators, as well as surface-active compounds, are recognised as essential to plant welfare. In this study, three cold-active Antarctic bacterial strains, i.e. Pseudomonas sp. ANT_H12B, Psychrobacter sp. ANT_H59 and Bacillus sp. ANT_WA51, were analysed. The physiological and genomic characterisation of these strains revealed their potential for plant growth promotion, reflected in the production of various biomolecules, including biosurfactants (that may lower the medium surface tension of even up to 53%) and siderophores (including ANT_H12B-produced mixed-type siderophore that demonstrated the highest production, reaching the concentration of up to 1.065 mM), increasing the availability of nutrients in the environment and neutralising fungal pathogens. Tested bacteria demonstrated an ability to promote the growth of a model plant, alfalfa, increasing shoots’ length and fresh biomass even up to 26 and 46% respectively; while their metabolites increased the bioavailability of iron in soil up to 40%. It was also revealed that the introduced strains did not disrupt physicochemical conditions and indigenous soil microbial composition, which suggests that they are promising amendments preserving the natural biodiversity of soil and increasing its fertility.

Identification of a New Antifungal Peptide W1 From a Marine Bacillus amyloliquefaciens Reveals Its Potential in Controlling Fungal Plant Diseases

“…Recently, researchers have isolated several antifungal microbes from the polar regions, such as Bacillus sp . ANT_WA51, B. amyloliquefaciens PC3 and Penicillium chrysogenum A096, which produce active antifungal peptides and show potential application values in agriculture ( Chen et al, 2013 ; Cui et al, 2017 ; Ding et al, 2018 , 2019 ; Styczynski et al, 2022 ). Therefore, screening for antifungal bacteria from the polar regions has become a new approach to controlling agricultural diseases ( Núñez-Montero and Barrientos, 2018 ).…”

Metabolically versatile psychrotolerant Antarctic bacterium Pseudomonas sp. ANT_H12B is an efficient producer of siderophores and accompanying metabolites (SAM) useful for agricultural purposes

“…Pseudomonas sp. ANT_H12B genome consists of 6 276 261 base pairs (58.57% GC content) and contains 6168 genes [ 28 ].…”

“…Genomic DNA extraction (cetyl trimethylammonium bromide /lysozyme method), sequencing (Illumina MiSeq platform) and basic genomic analysis (RAST, PATRIC and KEGG services) of Pseudomonas sp. ANT_H12B were performed and described in our previous work [ 28 ]. In this study additional genomic analysis was used to characterize the genetic background of the phenotypic profile of Pseudomonas sp.…”

“…In our previous paper we described Pseudomonas sp. ANT_H12B, a psychrotolerant siderophores producer, which exhibited PGP properties with regard to alfalfa ( Medicago sativa L.) [ 28 ]. Due to these characteristics ANT_H12B could potentially be used for the manufacturing of biostimulating agricultural products, however, its biotechnological potential was not fully revealed, especially according to the optimization of siderophores production and the potential PGP role of other accompanying metabolites.…”

Effects of Functionalized Materials and Bacterial Metabolites on Quality Indicators in Composts

“…Bacterial metabolites were obtained from RDLS Sp. z o.o., and their production process is described in the publication and patent application [ 28 , 29 ]. Selected chemical parameters of the materials used for composting are given in Table 2 .…”