Potassium solubilizing bacteria (KSB):: Mechanisms, promotion of plant growth, and future prospects ­ A review

Abstract

Potassium (K) is considered as an essential nutrient and a major constituent within all living cells. Naturally, soils contain K in larger amounts than any other nutrients; however most of the K is unavailable for plant uptake. Application of chemical fertilizers has a considerably negative impact on environmental sustainability. It is known that potassium solubilizing bacteria (KSB) can solubilize K-bearing minerals and convert the insoluble K to soluble forms of K available to plant uptake. Many bacteria such as Acidothiobacillus ferrooxidans, Paenibacillus spp., Bacillus mucilaginosus, B. edaphicus, and B. circulans have capacity to solubilize K minerals (e.g., biotite, feldspar, illite, muscovite, orthoclase, and mica). KSB are usually present in all soils, although their number, diversity and ability for K solubilization vary depending upon the soil and climatic conditions. KSB can dissolve silicate minerals and release K through the production of organic and inorganic acids, acidolysis, polysaccharides, complexolysis, chelation, and exchange reactions. Hence, the production and management of biological fertilizers containing KSB can be an effective alternative to chemical fertilizers. This article presents an overview of current trends and challenges on KSB, mechanisms and their role in plant growth promotion, and eventually gives some perspectives for research on K in agriculture.Keywords: Bio-fertilizer, potassium bearing minerals; potassium solubilization, plant and bacteria interactions, PGPRs 898Etesami et al

Nutrient Concentration in Vegetative Organs of the Orchid <i>Laelia anceps</i> subsp. <i>anceps</i> Based on Mineral Fertilization and Biofertilization

“…3). According to Etesami et al (2017) the effect of PGPR on K availability and the interactions between PGPR and potassiumsolubilizing bacteria (KSB) must be addressed in future studies. Biofertilization and Min-Fert + Biofert increased the Ca concentration in roots (3.3 and 3.7 g·kg −1 , P = 0.0003) (Fig.…”

Beneficial bacteria activate nutrients and promote wheat growth under conditions of reduced fertilizer application

“…(3) production of plant growth regulators or phytohormones such as indole-3-acetic acid (IAA), cytokinins, and gibberellins [14,15]; (4) production of siderophores, 1-amino-cyclopropane-1 -carboxylate (ACC) deaminase, and hydrogen cyanate [16,17]; (5) and biological control of phytopathogens and insects by synthesizing antibiotics or fungicidal compounds or competiting with detrimental microorganisms [18,19].…”

An indigenous strain of potassium-solubilizing bacteria Bacillus pseudomycoides enhanced potassium uptake in tea plants by increasing potassium availability in the mica waste-treated soil of North-east India

“…Etesami et al . () mentioned that the main mechanism of KSB to solubilize K from bound form is the production of organic and inorganic acids. However, along with this, KSB can dissolve silicate minerals and release K through acidolysis, polysaccharides, complexolysis, chelation and exchange reactions.…”