Hydrogenophaga caeni sp. nov., isolated from activated sludge

Area of Science:

• Microbiology
• Environmental Science
• Wastewater Treatment

Background:

• Enhanced biological phosphorus removal (EBPR) systems utilize microbial communities for efficient nutrient cycling.
• Activated sludge processes are critical for wastewater treatment, harboring diverse bacterial populations.
• Understanding microbial diversity aids in optimizing wastewater treatment efficacy and environmental protection.

Purpose of the Study:

• To isolate and characterize a novel bacterial strain from an EBPR sequencing batch reactor.
• To determine the taxonomic and phylogenetic placement of the novel isolate.
• To propose a new species within the Hydrogenophaga genus.

Main Methods:

• Isolation of strain EMB71(T) from activated sludge.
• Phenotypic characterization including morphology, growth conditions, and biochemical tests.
• Chemotaxonomic analysis of fatty acids, polar lipids, and quinones.
• Molecular analysis using 16S rRNA gene sequencing and phylogenetic comparisons.

Main Results:

• Strain EMB71(T) is a facultatively aerobic, motile rod with specific growth requirements (15-35°C, pH 6.0-9.0).
• Predominant fatty acids include C(16:0) and summed feature 3; polar lipids are dominated by phosphatidylethanolamine.
• Genomic DNA G+C content is 61.6 mol%, with Q-8 as the major quinone.
• 16S rRNA gene sequence similarity to Hydrogenophaga type strains ranged from 95.1% to 96.9%.

Conclusions:

• Strain EMB71(T) represents a novel species of the genus Hydrogenophaga.
• The proposed name for this new species is Hydrogenophaga caeni sp. nov.
• This finding contributes to the taxonomic knowledge of the Comamonadaceae family and bacteria involved in wastewater treatment.