The increase in global travel and the incorrect and excessive use of antibiotics has led to an unprecedented rise in antibiotic resistance in bacterial and fungal populations. To overcome these problems, novel bioactive natural products must be discovered, which may be found in underexplored environments, such as estuarine habitats. In the present work, estuarine actinomycetotal strains were isolated with conventional and iChip techniques from the Tagus estuary in Alcochete, Portugal, and analysed for different antimicrobial bioactivities. Extracts were produced from the isolated cultures and tested for bioactivity against Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922, Aspergillus fumigatus ATCC 240305, Candida albicans ATCC 10231 and Trichophyton rubrum FF5. Furthermore, bioactive extracts were subjected to dereplication by high-performance liquid chromatography (HPLC) and high-resolution mass spectrometry (HRMS) to putatively identify their chemical components. In total, 105 isolates belonging to 3 genera were obtained. One which was isolated, MTZ3.1 ^T, represents a described novel taxon for which the name Streptomyces meridianus was proposed. Regarding the bioactivity testing, extracts from 12 strains proved to be active against S. aureus, 2 against E. coli, 4 against A. fumigatus, 3 against C. albicans and 10 against T. rubrum. Dereplication of bioactive extracts showed the presence of 28 known bioactive molecules, 35 hits have one or more possible matches in the DNP and 18 undescribed ones. These results showed that the isolated bacteria might be the source of new bioactive natural products.

全球旅行的增加以及抗生素的不正确和过度使用导致细菌和真菌种群的抗生素耐药性空前上升。为了克服这些问题，必须发现新的生物活性天然产物，这些天然产物可能存在于未开发的环境中，例如河口栖息地。在目前的工作中，利用传统技术和 iChip 技术从葡萄牙阿尔科切特的塔霍河河口分离出河口放线菌菌株，并分析了不同的抗菌生物活性。从分离的培养物中提取提取物，并测试其针对金黄色葡萄球菌ATCC 29213、大肠杆菌ATCC 25922、烟曲霉ATCC 240305、白色念珠菌ATCC 10231 和红色毛癣菌FF5 的生物活性。此外，通过高效液相色谱（HPLC）和高分辨率质谱（HRMS）对生物活性提取物进行去重复，以推测鉴定其化学成分。总共获得了属于3属的105个分离株。分离出的一个，MTZ3.1  ^T ，代表了一种所描述的新分类群，建议将其命名为 Meridianus 链霉菌。关于生物活性测试，12 株菌株的提取物被证明具有抗金黄色葡萄球菌活性，2 株抗大肠杆菌活性，4株抗烟曲霉活性，3 株抗白色念珠菌活性，10 株抗红色毛霉活性。生物活性提取物的去重复显示存在 28 种已知的生物活性分子，35 种命中在 DNP 中具有一种或多种可能的匹配，还有 18 种未描述的分子。这些结果表明，分离的细菌可能是新的生物活性天然产物的来源。