College of Life SciencesKey Laborary of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education)Collaborative Innovation Center for Mountain Ecology & Agro-Bioengineering (CICMEAB)Institute of Agro-Bioengineering, Guizhou University, Guiyang, 550025, Guizhou, China.
World J Microbiol Biotechnol. 2021 May 31;37(7):109. doi: 10.1007/s11274-021-03078-3.
Phosphate solubilizing microorganisms widely exist in plant rhizosphere soil, but report about the P solubilization and multiple growth-promoting properties of rare actinomycetes are scarce. In this paper, a phosphate solubilizing Tsukamurella tyrosinosolvens P9 strain was isolated from the rhizosphere soil of tea plants. Phosphorus-dissolving abilities of this strain were different under different carbon and nitrogen sources, the soluble phosphorus content was 442.41 mg/L with glucose and potassium nitrate as nutrient sources. The secretion of various organic acids, such as lactic acid, maleic acid, oxalic acid, etc., was the main mechanism for P solubilization and pH value in culture was very significant negative correlation with soluble P content. In addition, this strain had multiple growth-promoting characteristics with 37.26 μg/mL of IAA and 72.01% of siderophore relative content. Under pot experiments, P9 strain improved obviously the growth of peanut seedlings. The bacterial communities of peanut rhizoshpere soil were assessed after inoculated with P9 strain. It showed that there was no significant difference in alpha-diversity indices between the inoculation and control groups, but the P9 treatment group changed the composition of bacterial communities, which increased the relative abundance of beneficial and functional microbes, which relative abundances of Chitinophagaceae at the family level, and of Flavihumibacter, Ramlibacter and Microvirga at the genus level, were all siginificant increased. Specially, Tsukamurella tyrosinosolvens were only detected in the rhizosphere of the inoculated group. This study not only founded growth-promoting properties of T. tyrosinosolvens P9 strain and its possible phosphate solublizing mechanism, but also expected to afford an excellent strain resource in biological fertilizers.
解磷微生物广泛存在于植物根际土壤中，但有关稀有放线菌的溶磷和多种促生特性的报道较少。本文从茶树根际土壤中分离得到一株解磷游动放线菌 Tsukamurella tyrosinosolvens P9 菌株。该菌株在不同碳源和氮源条件下的溶磷能力不同，以葡萄糖和硝酸钾为营养源时，可溶性磷含量为 442.41mg/L。该菌株主要通过分泌乳酸、马来酸、草酸等多种有机酸来实现溶磷，且培养体系的 pH 值与可溶性磷含量呈极显著负相关。此外，该菌株还具有多种促生特性，其 IAA 产量为 37.26μg/mL，相对铁载体含量为 72.01%。盆栽试验表明，P9 菌株能明显促进花生幼苗的生长。接种 P9 菌株后，对花生根际土壤细菌群落进行评估。结果表明，接种组和对照组的α多样性指数无显著差异，但 P9 处理组改变了细菌群落的组成，增加了有益和功能微生物的相对丰度，在科水平上，Chitinophagaceae 的相对丰度显著增加，属水平上，Flavihumibacter、Ramlibacter 和 Microvirga 的相对丰度均显著增加。特别的是，Tsukamurella tyrosinosolvens 仅在接种组的根际中检测到。本研究不仅发现了 T. tyrosinosolvens P9 菌株的促生特性及其可能的溶磷机制，还为生物肥料提供了一种优良的菌株资源。
