John Paul Balmonte
Lehigh University, PA·Earth & Environmental Science
The average depth of the ocean is about 4,000 meters, so most of the microbes that break down organic carbon in the sea live under enormous pressure. These bacteria and archaea consume organic carbon and release carbon dioxide, and their activity helps determine where carbon and nutrients are regenerated and how much organic matter is preserved.
- Fields
Earth & Environmental Science
Microbiology & Immunology
Ecology & Evolution
- Topics
deep ocean
deep sea
marine microbes
- Grants
- 1 known grant, through Mar 2027
What they work on
- Compare how depressurization changes the activity of extracellular enzymes produced by deep-ocean microbial communities, using pressurization systems at sea and in the lab.
- Determine how pressures characteristic of bathypelagic and abyssopelagic depths affect surface-water-derived microbial communities and their enzymes.
- Measure hydrolysis rates of peptides and polysaccharides, two major classes of marine organic matter, under high pressure and in in situ incubations in Danish coastal waters and the open North Atlantic and Pacific Oceans.
- Develop methods to measure enzyme activities in situ in the deep ocean, and test whether pressure affects the selfish uptake of polysaccharides by marine microbes.
More about the research
Yet most measurements of their carbon cycling are made at surface pressures, because the specialized high-pressure equipment needed is rarely available. It therefore remains unknown how closely those measurements reflect what deep-sea microbes actually do at depth.
Why it matters
Measuring deep-sea microbial activity at realistic pressures could substantially improve estimates of how quickly carbon is recycled, and how much is preserved, in the deep ocean, a central part of the global carbon cycle. The work may also aid future efforts to identify enzymes that function well under high pressure.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Winifred Johnson
University of North Carolina Wilmington, NC·Earth & Environmental Science
Identify which marine microbial groups produce which osmolytes under nitrogen stress by pairing osmolyte measurements with transcriptomics in laboratory cultures.
Sheri Floge
Wake Forest University, NC·Earth & Environmental Science
Measure how much vitamin B1 and related vitamers are released by B1-producing picocyanobacteria and heterotrophic bacteria grown in pure cultures.
Jill McDermott
Lehigh University, PA·Earth & Environmental Science
Determine how the April 2025 eruption at 9°50'N East Pacific Rise reorganized crustal permeability and fluid pathways, using high-temperature vent fluid sampling paired with in situ temperature measurements.
The school
Lehigh University: 13 labs on PI Pages, $62M a year on research, 99 research doctorates a year.
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