Nitrate reduction by Paracoccus thiophilus strain LSL 251 under aerobic condition: Performance and intracellular central carbon flux pathways. (July 2020)

• Record Type: Journal Article
• Authors: Chen, Shengnan; Li, Sulin; Huang, Tinglin; Yang, Shangye; Liu, Kaiwen; Ma, Ben; Shi, Yinjie; Miao, Yutian
• Is Part Of: Bioresource technology. Volume 308(2020)
• Publication Date: 2020-07
• Subjects: Aerobic denitrification -- 13C-MFA -- Carbon metabolic distribution -- Paracoccus thiophilus; 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.2020.123301
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Strain LSL 251 was identified as Paracoccus thiophilus using 16S rRNA gene. LSL 251 removed 98.78% of nitrate and 94.79% of TOC under aerobic condition. RSM model found that the maximum TN removal efficiency was 98.43% 13 C-MFA revealed that carbon flux distributions were ED pathway and TCA cycle. Electrons were primarily donated as electron donor-NADH through TCA cycle. Abstract: The intracellular carbon metabolic flux pathways of denitrifying bacteria under aerobic conditions remain unclear. Here, a newly strain LSL251 was identified as Paracoccus thiophilus . Strain LSL251 removed 94.79% and 98.78% of total organic carbon and nitrate. 74.66% of nitrogen in culture system was lost as gaseous nitrogen. Moreover, 13 C stable isotopic labeling and metabolic flux analyses revealed that the primary intracellular carbon metabolic pathways were the Entner-Doudoroff pathway and the tricarboxylic acid (TCA) cycle. Electrons are primarily donated as direct electron donor-NADH through the TCA cycle. Furthermore, response surface methodology modeled that the highest total nitrogen removal efficiency was 98.43%, where the optimal parameters were C/N ratio of 8.00, 32.98 °C, 50.18 rpm, and initial pH of 7.73. All together, these results have shed new lights on intracellular central carbon metabolic distribution and flux pathways of aerobic denitrifying bacteria.