Institute of Zoology, University of Belgrade, Faculty of Biology, Studentski Trg 16, 11000, Belgrade, Serbia.
Institute for Biological Research "Siniša Stanković", National Institute of Republic of Serbia, University of Belgrade, Bulevar Despota Stefana 142, 11060, Belgrade, Serbia.
Naturwissenschaften. 2022 Mar 10;109(2):19. doi: 10.1007/s00114-022-01790-0.
Pygidial gland secretions are used as repellent defensive allomones in ground beetles. We provide the first precise data on the chemical composition and antimicrobial potency of the secretion of the blue ground beetle, as well as on the morphology of its pygidial glands. The latter structures were not previously studied chemoecologically and morphologically, and we hypothesized that their secretion may have some antimicrobial action, as is the case with certain Carabus species. Gas chromatography-mass spectrometry (GC-MS) was used to identify methacrylic and angelic acids as dominant chemicals in the secretion from individuals of three populations of the blue ground beetle in Serbia. We tested its secretion against selected strains of medically important microorganisms. The secretion exibits antimicrobial action against certain bacterial species and all tested micromycetes. The most significant antifungal effect of the secretion was against Penicillium ochrochloron, which is more sensitive to the secretion than to commercial antifungal drugs ketoconazole and bifonazole. Bifonazole achieved minimum inhibitory concentrations against Trichoderma viride at more than three times higher value than did the secretion, indicating a significant antifungal effect of the secretion against this micromycete as well. Additionally, we tested commercially available standards of two dominant chemicals in the secretion to investigate their interaction and antimicrobial role in the secretion. Finally, we describe all glandular morpho-functional units of the blue ground beetle. Our results suggest that the secretion of the blue ground beetle may serve not only defensive but also antimicrobial functions, which likely aid the survival of this beetle in the microbial-rich forest litter habitat.
臀腺分泌物被用作地甲虫的驱避防御信息素。我们提供了蓝地甲虫分泌物的化学成分和抗菌活性以及其臀腺形态的第一个精确数据。这些结构以前没有从化学生态学和形态学的角度进行研究，我们假设它们的分泌物可能具有一些抗菌作用，就像某些 Carabus 物种一样。气相色谱-质谱联用 (GC-MS) 用于鉴定甲丙烯酸和当归酸作为塞尔维亚三个蓝地甲虫种群个体分泌物中的主要化学物质。我们测试了其分泌物对选定的重要医学微生物菌株的作用。分泌物对某些细菌和所有测试的真菌都具有抗菌作用。分泌物对青霉菌的抗真菌作用最为显著，其对青霉菌的敏感性比商业抗真菌药物酮康唑和比伏康唑更强。比伏康唑对绿色木霉的最小抑菌浓度值比分泌物高出三倍以上，表明分泌物对这种真菌也有显著的抗真菌作用。此外，我们还测试了分泌物中两种主要化学物质的市售标准，以研究它们在分泌物中的相互作用和抗菌作用。最后，我们描述了蓝地甲虫的所有腺体形态功能单位。我们的结果表明，蓝地甲虫的分泌物可能不仅具有防御作用，而且还具有抗菌作用，这可能有助于这种甲虫在富含微生物的森林凋落物栖息地中的生存。
