KaAhl, a Novel N-Acylhomoserine Lactonase from Kushneria avicenniae and Attenuated Effect on the Virulence of Erwinia carotovora

• Published in: Biotechnology and bioprocess engineering Vol. 26; no. 3; pp. 419 - 426
• Main Authors: Su, Yue, Shao, Mengru, Li, Tianying, Lin, Ling
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Society for Biotechnology and Bioengineering 01-06-2021; Springer Nature B.V; 한국생물공학회
• Subjects: Bacteria; Biotechnology; Chemistry; Chemistry and Materials Science; E coli; Erwinia carotovora; Gram-negative bacteria; Homoserine lactones; Industrial and Production Engineering; Lactones; Manganese; Metallo-β-lactamase; Metallography; Pathogenicity; Pathogens; Polypeptides; Research Paper; Salinity tolerance; Salt tolerance; Sodium chloride; Substrates; Thermal stability; Virulence; β Lactamase; 생물공학; acylhomoserine lactonase; quorum quenching; soft rot disease
• ISSN: 1226-8372; 1976-3816
• DOI: 10.1007/s12257-020-0230-3

N
-acylhomoserine lactones (AHLs) are autoinducers found in gram-negative bacteria and are ubiquitous in common plant pathogenic bacteria.
N
-acylhomoserine lactonase degrades the lactone ring of AHLs to achieve quorum quenching of phytopathogenic virulence genes. In this study, a novel AHL lactonase gene
KaAhl
was successfully cloned and identified from
Kushneria avicenniae
strain DSM 23439. KaAhl is encoded a 261-residue polypeptide belonging to the metallo-β-lactamase superfamily. The recombinant enzyme displayed maximum hydrolysis activity of 0.64 U/mg toward N-(3-oxooctanoyl)-L-homoserine lactone substrate at 30°C and pH 8.0. Besides, it had moderate thermal stability but exhibited a high salt tolerance showing approximate 50% relative activity in the presence of 35% concentrations of NaCl. Furthermore, the KaAhl was significantly promoted by Mn
2+
and Ni
2+
, which enhanced the lactonase activity to approximate 100% extent. In addition, it was observed that recombinant
Escherichia coli
BL21-pET28a-
KaAhl
producing KaAhl proteins could effectively inhibit the plant pathogenicity of
Erwinia carotovora
for 72 h, which might have great potential for controlling gram-negative pathogenic bacteria.