Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, Russia, 410049.
Institute for Cellular and Intracellular Symbiosis, Ural Branch of the Russian Academy of Sciences, 11 Pionerskaya Street, Orenburg, Russia, 460000.
Antonie Van Leeuwenhoek. 2024 Jul 23;117(1):105. doi: 10.1007/s10482-024-01989-3.
A rhizosphere strain, Achromobacter insolitus LCu2, was isolated from alfalfa (Medicago sativa L.) roots. It was able to degrade of 50% glyphosate as the sole phosphorus source, and was found resistant to 10 mM copper (II) chloride, and 5 mM glyphosate-copper complexes. Inoculation of alfalfa seedlings and potato microplants with strain LCu2 promoted plant growth by 30-50%. In inoculated plants, the toxicity of the glyphosate-copper complexes to alfalfa seedlings was decreased, as compared with the noninoculated controls. The genome of A. insolitus LCu2 consisted of one circular chromosome (6,428,890 bp) and encoded 5843 protein genes and 76 RNA genes. Polyphasic taxonomic analysis showed that A. insolitus LCu2 was closely related to A. insolitus DSM23807 on the basis of the average nucleotide identity of the genomes of 22 type strains and the multilocus sequence analysis. Genome analysis revealed genes putatively responsible for (1) plant growth promotion (osmolyte, siderophore, and 1-aminocyclopropane-1-carboxylate deaminase biosynthesis and auxin metabolism); (2) degradation of organophosphonates (glyphosate oxidoreductase and multiple phn clusters responsible for the transport, regulation and C-P lyase cleavage of phosphonates); and (3) tolerance to copper and other heavy metals, effected by the CopAB-CueO system, responsible for the oxidation of copper (I) in the periplasm, and by the efflux Cus system. The putative catabolic pathways involved in the breakdown of phosphonates are predicted. A. insolitus LCu2 is promising in the production of crops and the remediation of soils contaminated with organophosphonates and heavy metals.
一株根际土壤细菌，不动杆菌属（Achromobacter insolitus）LCu2 从紫花苜蓿（Medicago sativa L.）根系中分离得到。该菌能以草甘膦为唯一磷源将其降解 50%，并且能耐受 10 mM 氯化铜（II）和 5 mM 草甘膦-铜复合物。将该菌株接种到紫花苜蓿幼苗和马铃薯微型植株上，可使植物生长增加 30-50%。与未接种对照相比，接种植物中草甘膦-铜复合物对紫花苜蓿幼苗的毒性降低。不动杆菌属 LCu2 的基因组由一条环状染色体（6,428,890 bp）组成，编码 5843 个蛋白基因和 76 个 RNA 基因。多相分类学分析表明，基于 22 株模式菌株基因组的平均核苷酸同一性和多位点序列分析，不动杆菌属 LCu2 与不动杆菌属 DSM23807 密切相关。基因组分析揭示了可能与（1）植物生长促进（渗透调节剂、铁载体和 1-氨基环丙烷-1-羧酸脱氨酶生物合成和生长素代谢）；（2）有机膦酸盐降解（草甘膦氧化还原酶和多个 phn 簇负责膦酸盐的运输、调节和 C-P 裂合酶裂解）；（3）铜和其他重金属耐受性有关的基因，这些基因由 CopAB-CueO 系统调节，该系统负责铜（I）在周质中的氧化，以及 Cus 外排系统。预测了涉及膦酸盐分解的可能代谢途径。不动杆菌属 LCu2 有望用于生产作物和修复受有机膦酸盐和重金属污染的土壤。
