Copper is one of the essential trace dietary minerals for all living organisms, but is potentially toxic at higher concentrations, mainly due to the redox reactions in its transition state. Tolerance of microbes towards copper is primarily attributed to chelation and biosorption. In this study, marine-derived filamentous fungi were evaluated for their ability to remove Cu(II) from a culture medium. Further, the cellular response of a select isolate to salinity stress (0, 35 and 100 PSU) and Cu(II) stress (0, 100, and 500 ppm) was studied using the peptide mass fingerprinting technique, which revealed expression of 919 proteins, of which 55 proteins were commonly expressed across all conditions. Housekeeping proteins such as citrate synthase, pyruvate carboxylase, ribosomal proteins, ATP synthases, and more were expressed across all conditions. Reactive oxygen species scavenging proteins such as glutaredoxin, mitochondrial peroxiredoxins and thioredoxins were expressed under Cu(II) and salinity stresses individually as well as in combination. Up-regulation of glutaredoxin under Cu(II) stress with fold change values of 18.3 and 13.9 under 100 ppm and 500 ppm of Cu(II) indicated active scavenging of free radicals to combat oxidative damage. The common mechanisms reported were enzymatic scavenging of free radicals, activation of DNA damage and repair proteins and probable intracellular metal chelation. This indicated multiple stress mechanisms employed by the isolate to combat the singular and synergistic effects of Cu(II) and salinity stress.

中文翻译：

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海洋来源的丝状真菌 Penicillium chrysogenum 中的可变蛋白质表达响应于不同的铜浓度和盐度。

铜是所有生物体必需的微量膳食矿物质之一，但在较高浓度下具有潜在毒性，主要是由于其过渡态的氧化还原反应。微生物对铜的耐受性主要归因于螯合和生物吸附。在这项研究中，评估了海洋来源的丝状真菌从培养基中去除 Cu( II )的能力。此外，选定分离株对盐度胁迫（0、35 和 100 PSU）和 Cu( II ) 的细胞反应) 压力（0、100 和 500 ppm）使用肽质量指纹技术进行了研究，该技术揭示了 919 种蛋白质的表达，其中 55 种蛋白质在所有条件下都普遍表达。管家蛋白，如柠檬酸合酶、丙酮酸羧化酶、核糖体蛋白、ATP 合酶等，在所有条件下均得到表达。活性氧清除蛋白如谷氧还蛋白、线粒体过氧化还原蛋白和硫氧还蛋白在 Cu( II ) 和盐度胁迫下单独或组合表达。上调的Cu（下谷氧还蛋白的II）与18.3倍变值的应力，并在100 ppm的和500ppm的Cu 13.9（II) 表示积极清除自由基以对抗氧化损伤。报道的常见机制是自由基的酶促清除、DNA 损伤的激活和修复蛋白质以及可能的细胞内金属螯合。这表明分离株采用多种胁迫机制来对抗 Cu( II ) 和盐度胁迫的单一和协同效应。