Do methanotrophs drive phosphorus mineralization in soil ecosystem?

Area of Science:

• Environmental Microbiology
• Soil Science
• Biogeochemistry

Background:

• Phosphorus (P) is an essential nutrient for soil ecosystems, but its availability is often limited by its presence in unavailable inorganic and organic forms.
• Methane (CH4) oxidation by methanotrophic microorganisms is a key process in the carbon cycle, but its interaction with nutrient cycling, particularly phosphorus, is not fully understood.

Purpose of the Study:

• To investigate the linkage between methane consumption and the mineralization of different phosphorus sources in soil.
• To determine the effect of methane oxidation on the solubilization of inorganic and organic phosphorus.
• To assess the impact of methane consumption on microbial community structure and function related to phosphorus cycling.

Main Methods:

• Incubation experiments with soils subjected to repeated methane (CH4) feeding cycles.
• Addition of inorganic (Ca3(PO4)2) and organic (sodium phytate) phosphorus sources.
• Measurement of methane consumption rates, phosphorus solubilization, acid phosphatase activity, and abundance of 16S rRNA and pmoA genes.

Main Results:

• Methane consumption rates were significantly stimulated by the addition of both inorganic and organic phosphorus sources, with organic P showing a greater effect.
• Methane oxidation promoted the solubilization of inorganic P and increased acid phosphatase activity, indicating enhanced P mineralization.
• The abundance of 16S rRNA and pmoA genes, markers for microbial activity and methanotrophs, increased with higher methane consumption rates.

Conclusions:

• Methane consumption actively drives the mineralization of previously unavailable inorganic and organic phosphorus in soil ecosystems.
• The findings highlight a crucial link between carbon cycling (methane oxidation) and phosphorus availability, with implications for soil fertility and microbial community dynamics.