Planctomycetes are a phylogenetic group of bacteria with complex cell organization, large genomes and a wide spectrum of genome-encoded secondary metabolites. As suggested by analysis of available planctomycete genomes, these bacteria represent a promising source of potentially novel biologically active compounds. The number of cultured planctomycetes, however, remains limited. This study was undertaken in order to assess the presence of antimicrobial activity and its spectrum in the recently described freshwater planctomycete Lacipirellula parvula PX69T representing the novel family Lacipirellulaceae. The genome of strain PX69T contained 6 gene clusters encoding type III polyketide synthases, non-ribosomal peptide synthetases, and other secondary metabolites, which displayed low similarity to those in other bacteria. Strain PX69T was shown to exhibit antimicrobial activity against a number of test microorganisms. The highest antimicrobial activity, up to 83‒87% of growth inhibition, was observed against Staphylococcus aureus and Candida albicans. The medium composition and the cultivation time have been optimized in order to maximize antimicrobial activity of strain PX69T.

中文翻译：

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一种新型淡水浮游菌 Lacipirellula parvula PX69T 的抗菌活性

Planctomycetes 是一组系统发育细菌，具有复杂的细胞组织、大基因组和广泛的基因组编码的次级代谢产物。正如对可用浮菌属基因组的分析所表明的那样，这些细菌代表了潜在的新型生物活性化合物的有希望的来源。然而，培养的浮游菌的数量仍然有限。进行这项研究是为了评估最近描述的淡水浮生菌 Lacipirellula parvula PX69T 中抗菌活性的存在及其谱，代表了新的 Lacipirellulaceae 家族。菌株PX69T基因组包含6个基因簇，分别编码III型聚酮合酶、非核糖体肽合成酶和其他次级代谢产物，与其他细菌的相似度较低。菌株 PX69T 显示出对许多测试微生物的抗微生物活性。对金黄色葡萄球菌和白色念珠菌的抗菌活性最高，高达 83-87% 的生长抑制。培养基成分和培养时间已经过优化，以最大限度地提高 PX69T 菌株的抗菌活性。