Conjugal transfer of hydrogen-oxidizing ability of Alcaligenes hydrogenophilus to Pseudomonas oxalaticus

Area of Science:

• Microbiology
• Bacterial genetics
• Metabolic engineering

Background:

• Hydrogen-oxidizing bacteria play a crucial role in the hydrogen cycle.
• Understanding the genetic basis of hydrogen oxidation is key for biotechnological applications.
• Conjugal transfer is a significant mechanism for horizontal gene transfer in bacteria.

Purpose of the Study:

• To investigate the conjugal transfer of hydrogen-oxidizing ability (Hox) in Alcaligenes hydrogenophilus.
• To determine the efficiency of plasmid transfer between different bacterial species.
• To assess the stability and functionality of transferred genes in new hosts.

Main Methods:

• Conjugation experiments were performed between Alcaligenes hydrogenophilus and Pseudomonas oxalaticus strains.
• Plasmid pHG21-a, encoding hydrogenases, was used for transfer studies.
• Growth characteristics and hydrogen-oxidizing capacity of transconjugant strains were evaluated.

Main Results:

• Conjugal transfer of plasmid pHG21-a occurred most frequently at 25°C, while optimal growth was at 30°C.
• The plasmid was successfully transferred from A. hydrogenophilus to Pseudomonas oxalaticus OX1 and OX4.
• Transconjugant strains acquired the ability for autotrophic growth using H2 and CO2.
• Plasmid pHG21-a demonstrated stable maintenance in the Pseudomonas hosts.

Conclusions:

• Hydrogen-oxidizing ability can be effectively transferred between bacterial species via conjugation.
• Plasmid pHG21-a facilitates stable acquisition of autotrophic growth on H2 and CO2 in new hosts.
• This study provides insights into bacterial H2 metabolism and potential for metabolic engineering.