Ecotoxicological response of Spirulina platensis to coexisted copper and zinc in anaerobic digestion effluent

Ting Zhou; Xuan Li; Qi Zhang; Shiman Dong; Huan Liu; Yuhuan Liu; Alex V Chaves; Peter J Ralph; Roger Ruan; Qilin Wang

doi:10.1016/j.scitotenv.2022.155874

Ecotoxicological response of Spirulina platensis to coexisted copper and zinc in anaerobic digestion effluent

Sci Total Environ. 2022 Sep 1:837:155874. doi: 10.1016/j.scitotenv.2022.155874. Epub 2022 May 11.

Authors

Ting Zhou¹, Xuan Li², Qi Zhang³, Shiman Dong⁴, Huan Liu², Yuhuan Liu⁵, Alex V Chaves⁶, Peter J Ralph⁷, Roger Ruan⁸, Qilin Wang⁹

Affiliations

¹ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia; State Key Laboratory of Food Science and Technology, Engineering Research Center for Biomass Conversion, Ministry of Education, Nanchang University, Nanchang, Jiangxi 330047, China.
² Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia.
³ State Key Laboratory of Food Science and Technology, Engineering Research Center for Biomass Conversion, Ministry of Education, Nanchang University, Nanchang, Jiangxi 330047, China.
⁴ College of Tropical Crops, Hainan University, Haikou, Hainan 570228, China.
⁵ State Key Laboratory of Food Science and Technology, Engineering Research Center for Biomass Conversion, Ministry of Education, Nanchang University, Nanchang, Jiangxi 330047, China. Electronic address: liuyuhuan@ncu.edu.cn.
⁶ School of Life and Environmental Sciences, University of Sydney, Camperdown, NSW 2006, Australia.
⁷ Climate Change Cluster (C3), University of Technology Sydney, NSW 2007, Australia.
⁸ Center for Biorefining and Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Ave., St. Paul, MN 55108, USA.
⁹ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia. Electronic address: Qilin.Wang@uts.edu.au.

PMID: 35568173
DOI: 10.1016/j.scitotenv.2022.155874

Abstract

Copper ion (Cu²⁺) and zinc ion (Zn²⁺) are widely co-existent in anaerobic digestion effluent as typical contaminants. This work aims to explore how Cu²⁺-Zn²⁺ association affects physiological properties of S. platensis using Schlösser medium (SM) and sterilized anaerobic digestion effluent (SADE). Microalgae cells viability, biochemical properties, uptake of Cu²⁺ and Zn²⁺, and risk assessment associated with the biomass reuse as additives to pigs were comprehensively assessed. Biomass production ranged from 0.03 to 0.28 g/L in SM and 0.63 to 0.79 g/L in SADE due to the presence of Cu²⁺ and Zn²⁺. Peak value of chlorophyll-a and carotenoid content during the experiment decreased by 70-100% and 40-100% in SM, and by 70-77% and 30-55% in SADE. Crude protein level reduced by 4-41% in SM and by 65-75% in SADE. The reduction ratio of these compounds was positively related to the Cu²⁺ and Zn²⁺ concentrations. Maximum value of saturated and unsaturated fatty acids was both obtained at 0.3 Cu + 2.0 Zn (50.8% and 22.8%, respectively) and 25% SADE reactors (33.8% and 27.7%, respectively). Uptake of Cu in biomass was facilitated by Zn²⁺ concentration (> 4.0 mg/L). Risk of S. platensis biomass associated with Cu²⁺ was higher than Zn²⁺. S. platensis from SM (Cu²⁺ ≤ 0.3 mg/L and Zn²⁺ ≤ 4.0 mg/L) and diluted SADE (25% and 50% SADE) reactors could be used as feed additives without any risk (hazard index <1), which provides sufficient protein and fatty acids for pig consumption. These results revealed the promising application of using S. platensis for bioremediation of Cu²⁺ and Zn²⁺ in anaerobic digestion effluent and harvesting biomass for animal feed additives.

Keywords: Ecotoxicological response; Heavy metal; Risk assessment; S. platensis; Sterilized anaerobic digestion effluent.

MeSH terms

Anaerobiosis
Animals
Biomass
Copper* / metabolism
Copper* / toxicity
Spirulina* / metabolism
Swine
Zinc / metabolism
Zinc / toxicity

Substances

Copper
Zinc

Supplementary concepts

Arthrospira platensis