DefinePK

Abstract

Background and Objective: Phosphorus (P) is one of the most limiting nutrients for plant growth. Phosphorus deficiency is limiting crop production in many agricultural soils worldwide. The application of phosphorus solubilizing bacteria (PSB) to soils can replace or partially reduce using of inorganic P fertilizers. A bacteriophage, or phage, is a virus that infects a bacterial cell, taking over the host cell's genetic material. The four phages were propagated, purified, studied for the morphological properties, finally studying the genetic diversity. Materials and Methods: Obtained, examined the efficiency and identification of bacteria for solubilizing phosphorus. Isolation, studying the properties and studying genetic diversity. Results: Four virulent phages (Bv1, Bv2, Bv3 and Bv4) specific for Bacillus velezensis were isolated from the Egyptian soil. The Bacillus phages were purified by alternative low and high-speed centrifugation methods. Electron micrographs showed that phages appeared to be a member of the Siphoviridae family based on their structure and particle morphology (the particles have a head and long non-contractile tail). Sodium Dodecyl Sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) technique was performed to determine the properties of viral proteins. It was found that the Bv1 virus had five structural proteins, while Bv2 and Bv3 virus had eight structural proteins and finally, the Bv4 virus had ten structural proteins. The purity and quantity of isolated DNAs were determined spectrophotometrically. Data showed that the concentration of Bv1 DNA was 0.75 μg, Bv2 DNA and Bv3 DNA was 0.60 μg and finally Bv4 DNA 0.55 μg μL–1. The analysis of genetic material of B. velezensis phages was determined based on both the ISSR-PCR technique and the effect of restriction enzymes. Data showed different amplification patterns with all phages. Conclusion: The bacteriophages of B. velezensis were isolated from soil, propagated, purified, study some of its properties.