Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, SP, Brazil.
FEMS Microbiol Ecol. 2012 Dec;82(3):692-702. doi: 10.1111/j.1574-6941.2012.01439.x. Epub 2012 Jul 30.
Species of Microcystis are the most common bloom-forming cyanobacteria in several countries. Despite extensive studies regarding the production of bioactive cyanopeptides in this genus, there are limited data on isolated strains from Brazil. Three Microcystis sp. strains were isolated from the Salto Grande Reservoir (LTPNA01, 08 and 09) and investigated for the presence of mcy genes, microcystins and other cyanopeptides. Microcystin and microginin production was confirmed in two isolates using high-resolution tandem mass spectrometry after electrospray ionization (ESI-Q-TOF), and the structures of two new microginin congeners were proposed (MG756 Ahda-Val-Leu-Hty-Tyr and MG770 MeAhda-Val-Leu-Hty-Tyr). The biosynthesis profile of the identified cyanopeptides was evaluated at different growth phases via a newly developed HPLC-UV method. Results demonstrated no substantial differences in the production of microcystins and microginins after data normalization to cell quota, suggesting a constitutive biosynthesis. This study represents the first confirmed co-production of microginins and microcystins in Brazilian strains of Microcystis sp. and highlights the potential of Brazilian cyanobacteria as a source of natural compounds with pharmaceutical interest.
微囊藻属的物种是几个国家中最常见的形成水华的蓝藻。尽管针对该属生物活性蓝藻肽的产生进行了广泛的研究，但有关巴西分离株的资料有限。从 Salto Grande 水库中分离出了 3 株微囊藻属（LTPNA01、08 和 09）菌株，并对其 mcy 基因、微囊藻毒素和其他蓝藻肽进行了研究。使用电喷雾电离（ESI-Q-TOF）后进行高分辨率串联质谱分析，在两种分离株中证实了微囊藻毒素和微囊藻素的产生，并提出了两种新的微囊藻素同系物（MG756 Ahda-Val-Leu-Hty-Tyr 和 MG770 MeAhda-Val-Leu-Hty-Tyr）的结构。通过新开发的 HPLC-UV 方法，在不同的生长阶段评估了鉴定出的蓝藻肽的生物合成谱。结果表明，在对细胞丰度进行归一化后，微囊藻毒素和微囊藻素的产生没有明显差异，这表明其生物合成具有组成型。本研究代表了首次在巴西微囊藻属菌株中证实微囊藻素和微囊藻素的共同产生，并强调了巴西蓝藻作为具有药物应用潜力的天然化合物来源的潜力。
