Effect of polyhydroxyalkanoates on the microbial reductive dechlorination of polychlorinated biphenyls and competing anaerobic respirations in a marine microbial culture. (January 2023)

• Record Type: Journal Article
• Authors: Botti, Alberto; Biagi, Elena; Musmeci, Eliana; Breglia, Alessia; Degli Esposti, Micaela; Fava, Fabio; Zanaroli, Giulio
• Is Part Of: Marine pollution bulletin. Volume 186(2023)
• Publication Date: 2023-01
• Subjects: Polychlorinated biphenyls (PCBs) -- Polyhydroxyalkanoates (PHAs) -- Reductive dehalogenation -- Sulfate-reduction -- Methanogenesis -- Marine sediments; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2022.114458
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: The effect of polyhydroxyalkanoates (PHAs) with different composition on the reductive dechlorination activity of a polychlorinated biphenyls (PCBs) dechlorinating marine microbial community and on the activity of sulfate-reducing (SRB) and methanogenic bacteria (MB), were investigated in marine sediment microcosms and compared with the main monomer, 3-hydroxybutyric acid (3HB). Despite PHAs were fermented more slowly than 3HB, all electron donors stimulated constantly sulfate-reduction, methanogenesis and, only transiently, PCB reductive dechlorination. No relevant differences were observed with different compositions of PHAs. According to electron balances, the majority of the supplied electrons (50 %) were consumed by SRB and to less extent by MB (9–31 %), while a small percentage (0.01 %) was delivered to OHRB. In the studied conditions PHAs were confirmed as potential slow‑hydrogen releasing compounds in marine environment but their fermentation rate was sufficiently high to mainly stimulate the competitors of organohalide respring bacteria for electron donors. Graphical abstract: Unlabelled Image Highlights: Polyhydroxyalkanoates act as slow hydrogen releasing compounds in marine sediments. Polyhydroxyalkanoates stimulate transiently PCB reductive dechlorination. Polyhydroxyalkanoates stimulate mainly competitors of organohalide respiring bacteria. Tuning the fermentation rate may be a key factor for promoting organohalide respiration.