Spatial-temporal modeling of metabolic gas exchange in ripening tomato

25 Jan 2025
Job Information

Organisation/Company

KU Leuven

Research Field

Biological sciences » Biological engineering

Researcher Profile

First Stage Researcher (R1)

Country

Belgium

Application Deadline

20 Mar 2025 - 00:00 (UTC)

Type of Contract

Temporary

Job Status

Full-time

Hours Per Week

38 hours/week

Offer Starting Date

1 Apr 2025

Is the job funded through the EU Research Framework Programme?

Not funded by a EU programme

Reference Number

BAP-2025-48

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

The ripening process of fruit involves various changes, including softening, reduced acidity, production of aroma compounds, and color shifts. These changes are regulated and organized across both space and time. In climacteric fruits, ripening is marked by a significant increase in ethylene production, accompanied by a surge in respiration. Respiration, a key part of central metabolism, provides the energy needed for fruit development, cellular maintenance, and biosynthesis.
Respiration, which consumes oxygen and produces carbon dioxide, creates gas concentration gradients within the fruit, driving diffusion of the gasses in and out of the tissue. Studies, including ours, have shown the existence of these gradients, which can lead to hypoxic areas inside the fruit, depending on its size, shape and tissue properties changing with ripening, and external gas levels.
Understanding the internal gas profiles of fruit is key to studying changes in central metabolism. We have used microsensors with tips smaller than 1 mm to measure oxygen profiles in intact apples, pears, and tomatoes. Additionally, we have developed high-resolution reaction-diffusion models to study gas transport in these fruits. These models simulate the movement of oxygen, carbon dioxide, and nitrogen using geometries obtained from X-ray computed tomography (XCT), incorporating respiration and fermentation kinetics along with carbon dioxide inhibition terms.
The aim of this PhD project is to advance our understanding of the spatial and temporal effects of climacteric ripening in tomato fruit. This will involve incorporating the fruit microstructure that leads to spatial gradients in metabolic gases (oxygen, carbon dioxide, and ethylene) at different ripening stages. You will enhance a 3D multiscale reaction-diffusion model to add ethylene transport, while accounting for changes in respiration during ripening. Novel methods will be developed to validate the gas transport model, and the influence of microstructure on gas movement will be examined using a fruit tissue generator. A benchmark respiration model based on Michaelis-Menten kinetics will be developed that incorporates dynamic mechanisms of ripening, along with an improved coupling between ethylene and respiration. A mathematical model will be created to link ethylene biosynthesis to its perception and signaling. The model will be validated using advanced sensors.

Where to apply

Website

https://easyapply.jobs/r/lpXB4Al23vMrYl3pniBO

Requirements

Research Field

Engineering

Education Level

Master Degree or equivalent

Languages

ENGLISH

Level

Excellent

Research Field

Biological sciences

Years of Research Experience

None

Additional Information
Benefits

The lab offers you a 4-year PhD position at the Arenberg Doctoral School. The lab will support you in all aspects in order to successfully obtain a PhD degree with a high level scientific training. You will be given opportunities to participate in national and international meetings and collaborate with experts in the field. Leuven is a small city with metropolic flair in the heart of Europe close to Brussels, and with a rich historic background of science and technology. With more than 40 000 students it provides a vibrant environment for both research and living.

Eligibility criteria

You will quickly develop skills and expertise through a unique combination of advanced engineering and biology techniques. Therefore, as an ideal candidate you have a diploma in bioscience engineering or related fields, with a good understanding of diffusion transport phenomena and/or a basis in fruit biology. You are eager to learn and search new knowledge in these areas and quickly acquire skills to work with available methods, instruments and software independently. You have already programmed yourself code in Matlab, python or similar and have a keen interest in working with advanced software for heat and mass transfer simulation, such as computational fluid dynamics software.
You speak English fluently, and integrate easily in our international postharvest group where we offer the required support and expertise to guide you successfully through your PhD. As with previous successful PhD students, you aim at high impact publications in journals such as New Phytologist, Plant Physiology, Postharvest Biology and Technology and Nature Foods.

Selection process

For more information please contact Dr. ir. Pieter Verboven, tel.: +32 16 32 14 53, mail: pieter.verboven@kuleuven.be or Prof. dr. ir. Bart Nicolai, tel.: +32 16 32 23 75, mail: bart.nicolai@kuleuven.be .
You can apply for this job no later than 20/03/2025 via the online application tool

Work Location(s)

Number of offers available

1

Company/Institute

KU Leuven

Country

Belgium

State/Province

Vlaams Brabant

City

Leuven

Postal Code

3000

Street

Leuven

Geofield

Contact

State/Province

Leuven

City

Vlaams Brabant

Street

Leuven

Postal Code

3000

E-Mail

pieter.verboven@kuleuven.be

STATUS: EXPIRED

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