Insights into the multi-targeted effects of free nitrous acid on the microalgae Chlorella sorokiniana in wastewater. (March 2022)

• Record Type: Journal Article
• Authors: Abbew, Abdul-Wahab; Qiu, Shuang; Amadu, Ayesha Algade; Qasim, Muhammed Zeeshan; Chen, Zhipeng; Wu, Zhengshuai; Wang, Lingfeng; Ge, Shijian
• Is Part Of: Bioresource technology. Volume 347(2022)
• Publication Date: 2022-03
• Subjects: Wastewater -- Free nitrous acid -- Microalgae -- Microalgal-bacterial consortium -- Nitritation; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2021.126389
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Physiological and transcriptomic analysis revealed FNA influences on microalgae. FNA influence is concentration-dependent and multi-targeted. FNA caused oxidative stress and membrane damage. FNA impaired electron transport, photosynthesis, and respiration. Peroxisomal, chlorophyll and carotenoid synthesis were stimulated. Abstract: Microalgal-bacterial consortium process (MBCP) proposed as an alternative to the activated sludge process contains free nitrous acid (FNA). FNA antimicrobial influences on nitrifiers have been demonstrated. However, its influence on microalgae is largely unknown, limiting the system stability of MBCP. This study revealed the multi-targeted responses of a model wastewater microalgae, Chlorella sorokiniana, to FNA exposure through physiological and transcriptomic analyses. Results showed a concentration-dependent FNA-influence as both microalgal growth and photosynthesis (Fv/Fm, rETR, Y(II), NPQ) inversely correlated with FNA doses. Increased ROS, MDA content (5.0-fold), SOD (2.7-fold), and LDH (12.0-fold) activities in the treatments revealed FNA-induced oxidative pressure. Moreover, RNA-sequencing results revealed significantly downregulated genes related to photosynthesis, respiration, nitrogen metabolism, and tricarboxylic acid cycle. Comparatively, peroxisome, chlorophyll, and carotenoid genes were upregulated. These findings elucidate the inhibitory mechanisms of FNA on microalgae and contribute towards the prospective practical application of the MBCP system for sustainable wastewater treatment.