Indicators signaling Arsenic (As) stress through physiology of microalgae using non-destructive methods like variable fluorescence are rare but requisite. This study reports stress markers indicating arsenic (As) toxicity (in two concentrations 11.25 µg/L and 22.5 µg/L compared to a control) exposed to a microalga (Diacronema lutheri), using fast repetition rate fluorometry (FRRf). Growth and physiological parameters such as cell density, chl a and the maximum quantum yield F_v/F_m showed coherence and impeded after the exponential phase (day 9 - day 12) in As treatments compared to the control (p < 0.05). On contrary photo-physiological constants were elevated showing higher optical (a_LHII) and functional [Sigma (σ_PSII)] absorption cross-section for the As treatments (p < 0.05) further implying the lack of biomass production yet an increase in light absorption. In addition, As exposure increased the energy dissipation by heat (NPQ-NSV) showing a strong relationship with the de-epoxidation ratio (DR) involving photoprotective pigments. Total As bioaccumulation by D. lutheri showed a strong affinity with Fe adsorption throughout the algal growth curve. This study suggests some prompt photo-physiological proxies signaling As contamination and endorsing its usefulness in risk assessments, given the high toxicity and ubiquitous presence of As in the ecosystem.

使用非破坏性方法（如可变荧光）通过微藻生理学发出砷 (As) 压力信号的指标很少见，但必不可少。本研究使用快速重复率荧光测定法 (FRRf)报告了暴露于微藻 (Diacronema lutheri) 的表明砷 (As) 毒性的应激标记（与对照相比，两种浓度分别为 11.25 µg/L 和 22.5 µg/L）。生长和生理参数，如细胞密度、叶绿素a和最大量子产率 F _v /F _m显示相干性，并在 As 处理后的指数阶段（第 9 天 - 第 12 天）与对照相比显示出一致性和阻碍（p < 0.05）。相反，光生理常数升高，显示出更高的光学（_LHII) 和 As 处理的功能性 [Sigma (σ _PSII )] 吸收截面 (p < 0.05) 进一步暗示缺乏生物质生产但光吸收增加。此外，暴露增加了热能耗散 (NPQ-NSV)，显示出与涉及光保护颜料的脱环氧化率 (DR) 密切相关。D. lutheri的总砷生物富集在整个藻类生长曲线中显示出与 Fe 吸附的强亲和力。鉴于 As 在生态系统中的高毒性和无处不在，这项研究提出了一些提示 As 污染的快速光生理代理信号，并支持其在风险评估中的有用性。