Light-Driven Electron Uptake from Nonfermentative Organic Matter to Expedite Nitrogen Dissimilation by Chemolithotrophic Anammox Consortia.
Environ Sci Technol
; 57(34): 12732-12740, 2023 08 29.
Article
in En
| MEDLINE
| ID: mdl-37590181
ABSTRACT
Nonphotosynthetic microorganisms are typically unable to directly utilize light energy, but light might change the metabolic pathway of these bacteria indirectly by forming intermediates such as reactive oxygen species (ROS). This work investigated the role of light on nitrogen conversion by anaerobic ammonium oxidation (anammox) consortia. The results showed that high intensity light (>20000 lx) caused ca. 50% inhibition of anammox activity, and total ROS reached 167% at 60,000 lx. Surprisingly, 200 lx light was found to induce unexpected promotion of the nitrogen conversion rate, and ultraviolet light (<420 nm) was identified as the main contributor. Metagenomic and metatranscriptomic analyses revealed that the gene encoding cytochrome c peroxidase was highly expressed only under 200 lx light. 15N isotope tracing, gene abundance quantification, and external H2O2 addition experiments showed that photoinduced trace H2O2 triggered cytochrome c peroxidase expression to take up electrons from extracellular nonfermentative organics to synthesize NADH and ATP, thereby expediting nitrogen dissimulation of anammox consortia. External supplying reduced humic acid into a low-intensity light exposure system would result in a maximal 1.7-fold increase in the nitrogen conversion rate. These interesting findings may provide insight into the niche differentiation and widespread nature of anammox bacteria in natural ecotopes.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Cytochrome-c Peroxidase
/
Anaerobic Ammonia Oxidation
Type of study:
Prognostic_studies
Language:
En
Journal:
Environ Sci Technol
Year:
2023
Document type:
Article
Affiliation country:
China