Total ammonia nitrogen inhibits medium-chain fatty acid biosynthesis by disrupting hydrolysis, acidification, chain elongation, substrate transmembrane transport and ATP synthesis processes.
Bioresour Technol
; 409: 131236, 2024 Oct.
Article
en En
| MEDLINE
| ID: mdl-39122132
ABSTRACT
This study used 16S rRNA gene sequencing and metatranscriptomic analysis to comprehensively illustrate how ammonia stress influenced medium-chain fatty acids (MCFA) biosynthesis. MCFA synthesis was inhibited at total ammonia nitrogen (TAN) concentrations above 1000 mg N/L. TAN stress hindered organic hydrolysis, acidification, and volatile fatty acids elongation. Chain-elongating bacteria (e.g., Clostridium_sensu_stricto_12, Clostridium_sensu_stricto_1, Caproiciproducens) abundance remained unchanged, but their activity decreased, partially due to the increased reactive oxygen species. Metatranscriptomic analysis revealed reduced activity of enzymes critical for MCFA production under TAN stress. Fatty acid biosynthesis pathway rather than reverse ß-oxidation pathway primarily contributed to MCFA production, and was inhibited under TAN stress. Functional populations likely survived TAN stress through osmoprotectant generation and potassium uptake regulation to maintain osmotic pressure, with NADH-ubiquinone oxidoreductase potentially compensating for ATP loss. This study enhances understanding of MCFA biosynthesis under TAN stress, aiding MCFA production system stability and efficiency improvement.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Adenosina Trifosfato
/
Ácidos Grasos
/
Amoníaco
Idioma:
En
Revista:
Bioresour Technol
Asunto de la revista:
ENGENHARIA BIOMEDICA
Año:
2024
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
Reino Unido