Chemical Ecology/Chemical Biology, University of Konstanz, Universitätstrasse 10, 78457, Konstanz, Germany.
Chembiochem. 2020 Nov 2;21(21):3151-3157. doi: 10.1002/cbic.202000404. Epub 2020 Jul 20.
When Streptomyces violaceoruber grows together with Streptomyces sp. MG7-G1, it reacts with strongly induced droplet production on its aerial mycelium. Initially the metabolite profile of droplets from S. violaceoruber in co-culture with Streptomyces sp. MG7-G1 was compared to samples from S. violaceoruber in single-culture by using high-performance liquid chromatography-mass spectrometry (HPLC-MS). Then, the exudate from agar plates of co-cultures and single cultures (after freezing and thawing) was also analysed. Several compounds were only observed when S. violaceoruber was grown in co-culture. Based on their high-resolution ESI mass spectra and their comparable retention times to the calcium-dependent antibiotics (CDAs) produced by S. violaceoruber, the new compounds were suspected to be deacylated calcium-dependent antibiotics (daCDAs), lacking the 2,3-epoxyhexanoyl residue of CDAs. This was verified by detailed analysis of the MS/MS spectra of the daCDAs in comparison to the CDAs. The major CDA compounds present in calcium ion-supplemented agar medium of co-cultures were daCDAs, thus suggesting that Streptomyces sp. MG7-G1 expresses a deacylase that degrades CDAs.
当紫色链霉菌与链霉菌 MG7-G1 共同生长时，它会在气生菌丝上产生强烈诱导的液滴反应。最初，通过高效液相色谱-质谱联用（HPLC-MS）比较了紫色链霉菌在与链霉菌 MG7-G1 共培养时的液滴代谢物图谱与紫色链霉菌单培养时的样品。然后，还分析了共培养和单培养琼脂平板的渗出物（冷冻和解冻后）。当紫色链霉菌在共培养中生长时，只观察到几种化合物。基于它们的高分辨率 ESI 质谱和与紫色链霉菌产生的钙依赖性抗生素（CDAs）相当的保留时间，这些新化合物被怀疑是去酰化钙依赖性抗生素（daCDAs），缺乏 CDAs 的 2,3-环氧己酰基残基。通过将 daCDAs 的 MS/MS 谱与 CDAs 进行详细分析，证实了这一点。共培养物在补充钙离子的琼脂培养基中存在的主要 CDA 化合物是 daCDAs，这表明链霉菌 MG7-G1 表达了一种去酰化酶，可降解 CDAs。
