Determination of bioremediation potentials and plant growth-promoting properties of bacillus species isolated from the rhizosphere of dactylorhiza urvilleana

Abstract

Industrial activities have been one of the biggest factors of environmental destruction by affecting natural resources for decades. Heavy metals, which are one of the greatest dangers especially for the biosphere, can be found in industrial waste. Heavy metals that enter agricultural areas through industrial wastewater cause heavy metals to accumulate in the soil after a certain period. These accumulated heavy metals become an important environmental problem, threatening the life of living beings due to their toxic properties. In soils contaminated with wastewater containing heavy metals, microorganism populations are severely damaged in terms of both number and diversity. This heavy metal accumulation in water and soil has become a global health threat. Alternative processes are needed in the fight against heavy metal pollution. Bioremediation activity, defined as the removal process of environmental pollutants through microorganisms and plants, has gained significant importance in recent years. In our study, the tolerance potentials of Bacillus species isolated from the rhizosphere of Dactylorhiza urvilleana (Steudel) Bauman in the Ovit plateau of Rize province to metals (such as copper, lead, zinc, iron and silver) were investigated. In addition, plant growth promoting Indole Acetic Acid (IAA) production, phosphate dissolution, and ACC (1-Aminocyclopropane-1-Carboxylic acid) deaminase production were determined. It was determined that the isolated Bacillus species had a wide pH growth range and some Bacillus species were salt tolerant. The results showed that Bacillus species have bioremediation potential and plant growth promoting properties. It is thought that the bacteria isolated from the study can be used to make areas with heavy metal pollution suitable for plant cultivation and act as plant growth promoters in these areas. These bacteria strains are planned to be used as cheaper and more effective methods in studies in agriculture or areas with heavy metal pollution.