Plant Growth-Promoting Halobacteria and Their Ability to Protect Crops from Abiotic Stress: An Eco-Friendly Alternative for Saline Soils

Arid and semi-arid soils have low productivity due to abiotic stresses associated with drought and salinity. Halobacteria can increase the yield of crops subjected to these stresses. These bacteria thrive in a wide range of salinity (1-25% NaCl) and also in the absence of NaCl and have direct and indirect mechanisms that promote plant growth.

There are very few studies that evaluate the impact of halobacteria on soil fertility and consider their effect on plant growth, especially in the situation of current climate change, soil degradation and soil salinization, as well as the criteria for selecting bacteria.

The selection of halobacteria has been based on a qualitative criterion that considers the morphology of colonies grown in media enriched with salts, mainly Na+, but not all bacteria growing in salt-enriched media are able to uptake Na+ ions. Therefore, it seems that it is more appropriate to apply a quantitative criterion for the selection of halobacteria, which could be their ability to capture Na+ ions in vitro. The use of suitable halobacteria in rhizospheres and evaluation as biofertilizers could contribute greatly to the recovery of saline soils.

Photo: Application of halobacteria and their metabolites to recover soil fertility and increase crop yield in soils degraded by salinity and drought. https://www.mdpi.com/2073-4395/12/4/804