Antarctic actinobacteria, which can be isolated from both soils and marine sediments, demonstrate a wide range of antimicrobial activities as well as significant biosynthetic potential as the producers of biologically active compounds. However, the actinobacterial diversity of the Antarctic region has not yet been sufficiently studied. The present study sought to examine the diversity and antibacterial activity of culturable actinobacteria isolated from the rhizosphere soil of Deschampsia antarctica (É. Desv.), which was collected from Galindez Island, Maritime Antarctic. Among the actinobacteria isolated using a 16S rRNA gene sequence-based phylogenetic analysis process, five genera, namely Streptomyces, Micromonospora, Umezawaea, Kribbella and Micrococcus, were identified. To the best of our knowledge, this is the first report to describe the isolation and initial characterisation of members of the genus Umezawaea from the Antarctic. The isolated actinobacteria were assayed to determine their activity against Gram-positive bacteria, Gram-negative bacteria and yeast. Among the isolated strains, only 30.2% were able to inhibit the growth of at least one of the tested pathogens. The polymerase chain reaction-based screening of the biosynthetic genes revealed the presence of type I polyketide synthases (65.1%), type II polyketide synthases (25.6%) and non-ribosomal peptide synthetases (9.3%) in the actinobacteria strains. The examination of the sensitivity/resistance to antibiotics profile of the actinobacteria strains revealed their high sensitivity in relation to the tested antibiotics. Taken together, the results showed that Antarctic actinobacteria demonstrate potential as the producers of natural bioactive compounds, which means that they represent a valuable prospect for further studies.

南极放线菌可以从土壤和海洋沉积物中分离出来，显示出广泛的抗菌活性以及作为生物活性化合物生产者的显着生物合成潜力。然而，南极地区的放线菌多样性尚未得到充分研究。本研究旨在检查从南极洲加林德兹岛采集的Deschampsia antarctica (É. Desv.)根际土壤中分离出的可培养放线菌的多样性和抗菌活性。中使用基于序列的16S rRNA基因的系统发育分析过程中分离的放线菌，五个属，即链霉菌属，小单孢，Umezawaea，鉴定了 Kribbella和微球菌。据我们所知，这是描述Umezawaea属成员的分离和初步特征的第一份报告来自南极。分析分离的放线菌以确定它们对革兰氏阳性菌、革兰氏阴性菌和酵母菌的活性。在分离的菌株中，只有 30.2% 能够抑制至少一种测试病原体的生长。基于聚合酶链反应的生物合成基因筛选显示放线菌菌株中存在 I 型聚酮化合物合酶 (65.1%)、II 型聚酮化合物合酶 (25.6%) 和非核糖体肽合成酶 (9.3%)。放线菌菌株对抗生素的敏感性/抗性的检查表明它们对测试的抗生素具有高敏感性。总之，结果表明南极放线菌显示出作为天然生物活性化合物生产者的潜力，