Département de Biologie, Faculté des Sciences de la Nature et de la Vie et Sciences de la Terre, Université de Ghardaia, BP 455, 47000, Ghardaïa, Algeria.
Laboratoire de Biologie des Systèmes Microbiens (LBSM), Ecole Normale Supérieure Cheikh Mohamed El Bachir El Ibrahimi, B.P. 92, 16050, Kouba, Algiers, Algeria.
Curr Microbiol. 2024 Oct 11;81(12):402. doi: 10.1007/s00284-024-03932-1.
The isolation of endophytic actinobacteria from the roots of wild populations of Artemisia herba-alba Asso, a medicinal plant collected from the arid lands of Algeria, is reported for the first time. Forty-five actinobacterial isolates were identified by molecular analysis and in vitro evaluated for antimicrobial activity and plant growth-promoting (PGP) abilities (1-Aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, nitrogen fixation, phosphate and potassium solubilization, ammonia, and siderophores production). The phylogenetic relationships based on 16S rRNA gene sequences show that the genus Nocardioides (n = 23) was dominant in the sampled localities. The remaining actinobacterial isolates were identified as Promicromonospora (n = 11), Streptomyces (n = 6), Micromonopora (n = 3), and Saccharothrix (n = 2). Only six (13.33%) strains (five Streptomyces and one Saccharothrix species) were antagonistic in vitro against at least one or more indicator microorganisms. The antimicrobial activity of actinobacterial strains targeted mainly Gram-positive bacteria. The results demonstrate that more than 73% of the isolated strains had ACC deaminase activity, could fix atmospheric nitrogen and were producers of ammonia and siderophores. However, only one (2.22%) strain named Saccharothrix sp. BT79 could solubilize phosphorus and potassium. Overall, many strains exhibited a broad spectrum of PGP abilities. Thus, A. herba-alba provides a source of endophytic actinobacteria that should be explored for their potential biological activities.
首次报道了从阿尔及利亚干旱地区采集的野生黄花蒿（Artemisia herba-alba Asso）根系中分离内生放线菌。通过分子分析鉴定了 45 个放线菌分离株，并对其进行了体外评估，以评估其抗菌活性和植物促生（PGP）能力（1-氨基环丙烷-1-羧酸（ACC）脱氨酶活性、固氮、磷酸盐和钾溶解、氨和铁载体生产）。基于 16S rRNA 基因序列的系统发育关系表明，诺卡氏菌属（n = 23）在采样地点占优势。其余的放线菌分离株被鉴定为普氏菌属（n = 11）、链霉菌属（n = 6）、小单孢菌属（n = 3）和糖多孢菌属（n = 2）。只有 6 株（13.33%）菌株（5 株链霉菌和 1 株糖多孢菌）在体外对至少一种或多种指示微生物具有拮抗作用。放线菌菌株的抗菌活性主要针对革兰氏阳性菌。结果表明，超过 73%的分离株具有 ACC 脱氨酶活性，能够固定大气氮，并且是氨和铁载体的产生者。然而，只有一株（2.22%）名为糖多孢菌 BT79 的菌株能够溶解磷和钾。总体而言，许多菌株表现出广谱的 PGP 能力。因此，黄花蒿为内生放线菌提供了一个来源，应该探索其潜在的生物活性。
