Mutation breeding of Aspergillus niger by atmospheric room temperature plasma to enhance phosphorus solubilization ability

Abstract

Background Phosphorus (P) is abundant in soils, including organic and inorganic forms. Nevertheless, most of P compounds cannot be absorbed and used by plants. Aspergillus niger v. Tiegh is a strain that can efficiently degrade P compounds in soils. Methods In this study, A. niger xj strain was mutated using Atmospheric Room Temperature Plasma (ARTP) technology and the strains were screened by Mo-Sb Colorimetry with strong P-solubilizing abilities. Results Compared with the A. niger xj strain, setting the treatment time of mutagenesis to 120 s, four positive mutant strains marked as xj 90–32, xj120–12, xj120–31, and xj180–22 had higher P-solubilizing rates by 50.3%, 57.5%, 55.9%, and 61.4%, respectively. Among them, the xj120–12 is a highly efficient P solubilizing and growth-promoting strain with good application prospects. The growth characteristics such as plant height, root length, and dry and fresh biomass of peanut (Arachis hypogaea L.) increased by 33.5%, 43.8%, 43.4%, and 33.6%, respectively. Besides available P, the chlorophyll and soluble protein contents also vary degrees of increase in the P-solubilizing mutant strains. Conclusions The results showed that the ARTP mutagenesis technology can improve the P solubilization abilities of the A. niger mutant strains and make the biomass of peanut plants was enhanced of mutant strains.

Keywords

• Aspergillus niger
• Atmospheric room temperature plasma
• Phosphate-solubilizing ability
• Mutagenesis