Metagenomic analysis revealed the potential of lactic acid bacteria in the improvement of natural saline-alkali land

Abstract The management and improvement of saline-alkali land is necessary for sustainable agricultural development. We conducted a field experiment to investigate the effects of spraying lactic acid bacteria (LAB) on the of cucumber and tomato plantation soil. Three treatments were designed, include spraying of non-sterilized/sterilized LAB preparation or water (control) to the soil of planting every 20 days. Treatment with either sterilized or viable LAB reduced the soil pH. Metagenomic sequencing revealed that the LAB-treated groups had higher alpha-diversity and more nitrogen fixing bacteria compared with the water-treated groups. Treatment with viable or sterilized LAB increased the complexity of soil microbial interactive network in different pattern. Differential enrichment of KEGG pathways and genes were observed between LAB-treated groups: changes in environmental information processing-related pathways in cucumber soil and metabolism-related pathways in tomato soil, respectively. RDA analysis revealed biomarker bacterial communities in different treatments were associated with soil pH and total nitrogen. Our study demonstrated that LAB might be a suitable strategy for decreasing soil pH and improving community structure of certain plants in saline-alkali land.