Related Experiment Video
Updated: Aug 14, 2026
08:28
Creating Rapid Oxygen Oscillations in Microbial Single-cell Growth Analysis using a Microfluidic Double-layer Device
Published on: July 18, 2025
Oxygen Responses and Mat Formation by Beggiatoa spp
M M Møller1, L P Nielsen, B B Jørgensen
1Institute of Ecology and Genetics, University of Aarhus, DK-8000 Aarhus C, Denmark.
Applied and Environmental Microbiology
|August 1, 1985
Summary
Beggiatoa bacteria exhibit a phobic response to oxygen, reversing movement when oxygen levels increase. This behavior helps them position within oxygen-sulfur interfaces and explains their vertical migration in sediments.
Area of Science:
- Microbiology
- Environmental Science
- Biophysics
Background:
- Beggiatoa are sulfur-oxidizing bacteria found in oxygen-rich environments.
- Their movement and positioning are crucial for survival in micro-gradients.
- Understanding their behavioral responses is key to ecological studies.
Purpose of the Study:
- To investigate the behavioral responses of Beggiatoa sp. filaments to oxygen gradients.
- To determine the sensitivity and response time of Beggiatoa to oxygen changes.
- To understand how these responses influence Beggiatoa mat structure and migration patterns.
Main Methods:
- Microscopy and oxygen microelectrodes were used to observe Beggiatoa filament movement.
- Controlled oscillations in oxygen tension were applied.
- Behavioral responses were studied in stable microgradients of oxygen.
Main Results:
- Beggiatoa filaments reversed direction in response to increasing oxygen tension.
- The phobic response to oxygen was sensitive to changes as low as <5% air saturation.
- Response time ranged from 20 to 50 seconds.
- Partial filament responses led to bending and coiling, aiding positioning in O(2)-H(2)S interfaces.
- Beggiatoa mat structure correlated with oxygen gradients.
- Vertical migration in illuminated sediments was linked to light and oxygen responses.
Conclusions:
- Beggiatoa exhibit a distinct oxygen-phobic response that dictates their movement and positioning.
- This behavior is critical for survival at the oxygen-hydrogen sulfide interface.
- Combined responses to light and oxygen explain vertical migration patterns in sediments.
Related Concept Videos
01:29Oxygen Requirements and Growth Patterns
Microorganisms exhibit diverse oxygen requirements and growth patterns driven by their metabolic strategies and environmental adaptations. Oxygen, while essential for many organisms, can also be toxic under certain conditions, shaping how microorganisms grow and survive.Oxygen Requirements of MicroorganismsMicroorganisms are classified based on their ability to use or tolerate oxygen:● Obligate aerobes like Mycobacterium tuberculosis need oxygen for energy production, as it serves as the...
01:25Microbial Mats
Microbial communities forming biofilms and mats represent complex, spatially structured ecosystems where metabolic processes are stratified according to light, oxygen, and nutrient gradients. Biofilms are initial colonization stages, only a few millimeters thick, while mature microbial mats can reach centimeter-scale thickness and display intricate vertical organization. Their structural and functional heterogeneity allows microorganisms to occupy distinct ecological niches within a few...
01:18Bioreactor Controls-II
In aerobic fermentations, oxygen is vital for microbial growth and metabolite production. Since air comprises only about 20% oxygen and the gas is poorly soluble in water—just 9 ppm at 20°C—supplying sufficient oxygen becomes a critical challenge, especially in high-demand processes like yeast growth or citric acid production. Even a fully saturated broth may offer only a few seconds of oxygen availability.To address this, sterile or scrubbed air is introduced into the fermentor via a sparger...
01:27Oxygen Transport in the Blood
Hemoglobin (Hb) is a crucial molecule in the human body, consisting of four polypeptide chains, each bound to an iron-containing heme group. This unique structure enables hemoglobin to bind to oxygen, with each molecule capable of combining with four molecules of oxygen, leading to rapid and reversible oxygen loading. When fully loaded with oxygen, it is called oxyhemoglobin, while hemoglobin that has released oxygen is called reduced hemoglobin or deoxyhemoglobin. As hemoglobin binds oxygen,...
01:24Regulation of Angiogenesis and Blood Supply
Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits. Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor...
01:20Gas Exchange and Transport
Gas exchange, the intake of molecular oxygen (O2) from the environment and the outflow of carbon dioxide (CO2) into the environment, is necessary for cellular function. Gas exchange during respiration occurs largely via the movement of gas molecules along pressure gradients. Gas travels from areas of higher partial pressure to areas of lower partial pressure. In mammals, gas exchange occurs in the alveoli of the lungs, which are adjacent to capillaries and share a membrane with them.