Suspended particulate matter (SPM), an important component of the natural water environment, can act as a carrier of many pollutants that affect aquatic organisms. In the present study, the effect of SPM obtained from Jinjiang Estuary on the physiological, biochemical, and photosynthetic properties of typical freshwater algae (Chlorella pyrenoidosa) was investigated. The results showed that under different concentrations of SPM treatment, the superoxide dismutase (SOD), catalase (CAT) activities, and malondialdehyde (MDA) content of C. pyrenoidosa increased, but the soluble protein content decreased. SPM with different particle sizes had less effect on SOD of C. pyrenoidosa, but showed a promoting effect on CAT and MDA as well as soluble protein content. In terms of photosynthetic activity, high concentrations (70, 90 mg/L) and small particle sizes (0–75, 75–120 μm) of SPM had a greater effect on the chlorophyll a content of C. pyrenoidosa. In addition, different concentrations of SPM had no significant effect on the potential photosynthetic activity of PS II (F_v/F₀) and the maximum quantum yield of PS II (F_v/F_m), but the inhibition of the initial slope (alpha), the maximum photosynthetic rate (ETR_max) and the semi-light saturation point (I_k) increased with the increase of SPM concentration. F_v/F₀, ETR_max, and I_k of C. pyrenoidosa showed some degree of recovery after inhibition in the presence of SPM of different particle sizes.

悬浮颗粒物（SPM）是自然水环境的重要组成部分，可以作为影响水生生物的许多污染物的载体。本研究旨在研究从晋江口获得的SPM对典型淡水藻类（蛋白核小球藻）生理、生化和光合特性的影响。结果表明，不同浓度SPM处理下，蛋白核糖藻超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性和丙二醛（MDA）含量升高，但可溶性蛋白含量降低。不同粒径的SPM对核糖体SOD影响较小，但对CAT、MDA以及可溶性蛋白含量有促进作用。在光合活性方面，高浓度（70、90 mg/L）和小粒径（0~75、75~120 μm）的SPM对蛋白核藻叶绿素a含量影响较大。此外，不同浓度的SPM对PS II的潜在光合活性（F _v /F ₀）和PS II的最大量子产率（F _v /F _m）没有显着影响，但对初始斜率（ α)、最大光合速率(ETR _max )和半光饱和点(I _k )随着SPM浓度的增加而增加。在不同粒径的SPM存在下，蛋白核棒状杆菌的F _v /F ₀、ETR _max和I _{k在抑制后表现出一定程度的恢复。}