Ecotoxic effects of combined exposure of microplastics and cadmium on Sinorhizobium fredii

doi:10.16178/j.issn.0528-9017.20250063

Abstract

Abstract:

To investigate the ecotoxic effects of combined exposure of microplastics and cadmium on soil microorganisms, the ecotoxic effects of mono-dispersed polystyrene microplastics (MPs) (0, 20, 100, 200 mg·L^-1) and cadmium (Cd²⁺) (4 mg·L^-1) on Sinorhizobium fredii were studied by single and combined exposure. The results showed that the growth of Sinorhizobium fredii was obviously inhibited under single MPs/Cd²⁺ exposure, while the activities of superoxide dismutase(SOD) and catalase(CAT) were significantly (p<0.05) increased. In addition, the concentration of superoxide anion, electrolyte leakage rate, proline and malondialdehyde contents in Sinorhizobium fredii increased first and then decreased with the increase of MPs/Cd²⁺ concentration. Under combined exposure, soluble protein content in Sinorhizobium fredii was significantly higher than that in single MPs/Cd²⁺ treatment group, SOD and CAT activities in Sinorhizobium fredii were increased. The results above indicated that under the combined exposure of MPs and Cd²⁺, Sinorhizobium fredii mitigated the ecotoxicity of a single pollutant to Sinorhizobium fredii by adjusting the content of osmotic substances and reducing the damage degree of biofilm.

Key words: microplastic, cadmium, Sinorhizobium fredii, ecotoxic effect

CLC Number:

YUAN Dan, WU Tianyu, QIN Yutian, YANG Yuxin, ZHAO Wei, SONG Xiaoyu, CHEN Dong, ZHANG Liang. Ecotoxic effects of combined exposure of microplastics and cadmium on Sinorhizobium fredii[J]. Journal of Zhejiang Agricultural Sciences, 2025, 66(12): 3093-3098.

Figures/Tables 4

References 21

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处理	电解质渗透率/%	可溶性蛋白含量/ (mg·g^-1)	脯氨酸含量/ (μg·g^-1)	丙二醛含量/ (μmol·g^-1)
0	35.0±0.6 g	28.9±0.6 a	5.3±0.6 d	2.2±0.2 h
T1	49.1±1.2 d	21.1±0.9 d	8.7±0.5 b	5.3±0.6 g
T2	51.4±0.3 c	16.6±0.8 e	10.4±1.0 a	8.6±0.3 f
T3	41.1±1.1 f	16.3±1.2 e	8.6±0.8 b	10.5±0.7 e
T4	58.2±0.9 a	17.5±0.9 e	5.8±0.6 d	22.5±1.2 a
T5	53.4±0.4 b	22.6±0.7 cd	5.6±0.6 d	13.3±0.6 d
T6	51.0±0.3 c	23.7±0.5 c	9.2±0.4 ab	18.3±1.0 c
T7	44.0±0.8 e	26.0±0.8 b	7.1±0.7 c	20.1±0.9 b

处理	电解质渗透率/%	可溶性蛋白含量/ (mg·g^-1)	脯氨酸含量/ (μg·g^-1)	丙二醛含量/ (μmol·g^-1)
0	35.0±0.6 g	28.9±0.6 a	5.3±0.6 d	2.2±0.2 h
T1	49.1±1.2 d	21.1±0.9 d	8.7±0.5 b	5.3±0.6 g
T2	51.4±0.3 c	16.6±0.8 e	10.4±1.0 a	8.6±0.3 f
T3	41.1±1.1 f	16.3±1.2 e	8.6±0.8 b	10.5±0.7 e
T4	58.2±0.9 a	17.5±0.9 e	5.8±0.6 d	22.5±1.2 a
T5	53.4±0.4 b	22.6±0.7 cd	5.6±0.6 d	13.3±0.6 d
T6	51.0±0.3 c	23.7±0.5 c	9.2±0.4 ab	18.3±1.0 c
T7	44.0±0.8 e	26.0±0.8 b	7.1±0.7 c	20.1±0.9 b