Screening and biodiversity analysis of cultivable inorganic phosphate–solubilizing bacteria in the rhizosphere of Hydrilla verticillata

RESEARCH ARTICLE Screening and biodiversity analysis of cultivable inorganic phosphate–solubilizing bacteria in the rhizosphere of Hydrilla verticillata Yong LiID1*, Huan Liu1, Xintao Yu1, Sidan Gong1, Zhilian Gong2 1 Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China, 2 School of Food and Biological Engineering, Xihua University, Chengdu, China * liyong@swjtu.edu.cn Abstract The inorganic phosphate–solubilizing bacteria (IPB) in the rhizosphere of Hydrilla verticillata can convert insoluble inorganic phosphorus in the environment into soluble phosphorus that can be directly absorbed and utilized by Hydrilla verticillata. In this research, the roots and rhizosphere sediments of Hydrilla verticillata were collected from high–organic matter urban landscape water. The National Botanical Research Institute’s Phosphate growth medium (NBRIP medium) was used to screen for efficient cultivable IPB. The 16S rRNA gene sequence analysis was used to determine the taxonomic affiliation of the strains, and ammonium molybdate spectrophotometry was used to detect the phosphate-solubilizing ability of the strains. The results show that a total of 28 IPB strains with good phosphate-sol- ubilizing effect are obtained from the roots and rhizosphere sediments of Hydrilla verticillata. These IPB strains belong to two phyla, four orders, seven classes, nine families, and nine genera. Among these, Bacillus and Acinetobacter are the dominant genera, and the strains SWIH-7, SWIP-6, SWIP-7, SWIP-13, SWIP-15 and SWIP-16 are potential new species.

The IPB strains isolated and screened in this research are rich in diversity, with potential new species and stable phosphate-solubilizing characteristic. These IPB strains are suitable for further development as microbial bacterial agents, which can be applied to promote the recovery of submerged plants in polluted water with high–organic matter, treatment of pol- luted water and ecological restoration of water. Introduction The problem of water pollution has become one of the most important environmental prob- lems in China and the world, which seriously threatens the safety of the water environment on which human beings depend. High–load sediment pollution is one of the water pollution, and controlling sediment endogenous pollution is the key concern of water environmental protec- tion and management [1]. Polluted water remediation methods include physical, chemical, biological and combined methods. Compared with physical and chemical methods, biological PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0297047 January 19, 2024 1 / 11 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Li Y, Liu H, Yu X, Gong S, Gong Z (2024) Screening and biodiversity analysis of cultivable inorganic phosphate–solubilizing bacteria in the rhizosphere of Hydrilla verticillata. PLoS ONE 19(1): e0297047. https://doi.org/10.1371/journal. pone.0297047 Editor: Estibaliz Sansinenea, Beneme´rita Universidad Auto´noma de Puebla: Benemerita Universidad Autonoma de Puebla, MEXICO Received: November 5, 2023 Accepted: December 26, 2023

Published: January 19, 2024 Peer Review History: PLOS recognizes the benefits of transparency in the peer review process; therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. The editorial history of this article is available here: https://doi.org/10.1371/journal.pone.0297047 Copyright: © 2024 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are available from the National Center for Biotechnology Information at https://www.ncbi.