Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW 2480, Australia.
Southern Cross Plant Science, Southern Cross University, Lismore, NSW 2480, Australia.
Mar Drugs. 2019 May 3;17(5):264. doi: 10.3390/md17050264.
The secondary metabolite Tyrian purple, also known as shellfish purple and royal purple, is a dye with historical importance for humans. The biosynthetic origin of Tyrian purple in Muricidae molluscs is not currently known. A possible role for symbiotic bacteria in the production of tyrindoxyl sulphate, the precursor to Tyrian purple stored in the Australian species, , has been proposed. This study aimed to culture bacterial symbionts from the purple producing hypobranchial gland, and screen the isolates for bromoperoxidase genes using molecular methods. The ability of bromoperoxidase positive isolates to produce the brominated indole precursor to Tyrian purple was then established by extraction of the culture, and analysis by liquid chromatography-mass spectrometry (LC-MS). In total, 32 bacterial isolates were cultured from hypobranchial glands, using marine agar, marine agar with hypobranchial gland aqueous extracts, blood agar, thiosulphate citrate bile salts sucrose agar, and cetrimide agar at pH 7.2. These included 26 spp., two spp., one sp., one sp., one sp. and one sp. The two species were the only isolates found to have coding sequences for bromoperoxidase enzymes. LC-MS analysis of the supernatant and cell pellets from the bromoperoxidase producing spp. cultured in tryptone broth, supplemented with KBr, confirmed their ability to produce the brominated precursor to Tyrian purple, tyrindoxyl sulphate. This study supports a potential role for symbiotic spp. in the biosynthesis of Tyrian purple.
次生产物天青色素，又称贝类紫和皇家紫，是一种具有历史意义的人类染料。目前还不知道贻贝类软体动物中天青色素的生物合成起源。有人提出，共生细菌可能在澳大利亚物种 储存的天青色素前体硫代硫酸酯 Tyrindoxyl 的产生中起作用。本研究旨在从产生紫色的腹神经节中培养细菌共生体，并使用分子方法筛选分离物中的溴过氧化物酶基因。然后通过提取培养物并通过液相色谱-质谱（LC-MS）分析来确定溴过氧化物酶阳性分离物产生天青色素的溴化吲哚前体的能力。总共从 腹神经节中培养了 32 个细菌分离物，使用了海洋琼脂、含腹神经节水提取物的海洋琼脂、血琼脂、硫代硫酸盐柠檬酸盐胆汁盐蔗糖琼脂和 pH 为 7.2 的 cetrimide 琼脂。其中包括 26 种 种、2 种 种、1 种 种、1 种 种、1 种 种和 1 种 种。只有两种 种被发现具有编码溴过氧化物酶的基因序列。在补充了 KBr 的胰蛋白胨肉汤中培养的具有溴过氧化物酶的 种的上清液和细胞沉淀的 LC-MS 分析证实了它们产生天青色素前体 Tyrindoxyl sulphate 的能力。本研究支持共生 种在天青色素生物合成中的潜在作用。
