Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Energy conservation in aerobically grown Staphylococcus aureus.

Z Tynecka1, Z Szcześniak, A Malm

  • 1Department of Pharmaceutical Microbiology, Medical Academy, Lublin, Poland.

Research in Microbiology
|November 30, 1999
PubMed
Summary

This study explores how Staphylococcus aureus conserves energy when growing aerobically. The bacteria were starved and given either glutamate or L-lactate as energy sources. The researchers found that the bacteria used two types of oxidases to process these substrates. Glutamate oxidation was tightly linked to ATP synthesis, while L-lactate oxidation was loosely linked. The study also identified two potential energy coupling sites in the respiratory chain. These findings help clarify how different substrates influence energy conservation in bacterial cells.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Bacterial aetiology of recalcitrant acute otitis media in 62 children-high risk of pathogen colonisation after treatment.

Clinical otolaryngology : official journal of ENT-UK ; official journal of Netherlands Society for Oto-Rhino-Laryngology & Cervico-Facial Surgery·2017
Same author

Nasopharyngeal vs. adenoid cultures in children undergoing adenoidectomy: prevalence of bacterial pathogens, their interactions and risk factors.

Epidemiology and infection·2015
Same author

Transpleural cardioplasty in achalasia; operation results and sequelae.

Thorax·2014
Same author

Exposure to candesartan during the first trimester of pregnancy in type 1 diabetes: experience from the placebo-controlled DIabetic REtinopathy Candesartan Trials.

Diabetologia·2011
Same author

Seven-year follow-up of a randomized clinical trial comparing proton-pump inhibition with surgical therapy for reflux oesophagitis.

The British journal of surgery·2007
Same author

Changes of gastric mucosal architecture during long-term omeprazole therapy: results of a randomized clinical trial.

Alimentary pharmacology & therapeutics·2006

Area of Science:

  • Microbial metabolism within bioenergetics
  • Bacterial respiratory chain research
  • Energy conservation in prokaryotic systems

Background:

Understanding how bacteria conserve energy during aerobic respiration is central to microbial physiology. Prior research has shown that bacteria utilize various terminal oxidases to manage substrate oxidation and ATP synthesis. However, the specific roles of menaquinol oxidases in energy coupling remain unclear. Established knowledge includes the presence of multiple oxidases in bacterial electron transport chains. This paper's contribution lies in identifying which oxidases are involved in energy conservation in Staphylococcus aureus. While it is known that bacteria can oxidize substrates like glutamate and lactate, the coupling mechanisms differ. The current study addresses how these substrates interact with different oxidases and influence ATP synthesis. It also explores the coupling efficiency of these processes in whole cells versus lysates. This work adds clarity to the functional roles of specific oxidases in energy conservation.

Purpose Of The Study:

Keywords:
Bacterial energy metabolismMenaquinol oxidase functionStaphylococcus aureus respirationATP synthesis coupling

Frequently Asked Questions

The main finding is that glutamate oxidation is tightly coupled to ATP synthesis, while L-lactate oxidation is loosely coupled.

L-lactate oxidation occurs via two oxidases: the ba3-type and the bo-type menaquinol oxidases.

CCCP is used to disrupt the proton gradient, which helps assess the coupling efficiency of substrate oxidation to ATP synthesis.

The P/O ratio is 1.5 for glutamate and 0.03 for L-lactate, indicating tighter coupling for glutamate.

Related Experiment Videos

The aim of this study was to determine the role of menaquinol oxidases in energy conservation during aerobic growth of Staphylococcus aureus. The specific problem addressed is the unclear mechanism of how different substrates interact with oxidases to generate ATP. The motivation stems from the need to understand bacterial energy metabolism under starvation conditions. The researchers focused on two substrates, glutamate and L-lactate, and their oxidation pathways. They also sought to identify which oxidases are responsible for ATP synthesis in whole cells. The study aimed to compare the efficiency of energy coupling between these substrates. By using KCN and CCCP, the authors tested the involvement of different oxidases in the process. This approach allowed them to distinguish between tightly and loosely coupled oxidation reactions.

Main Methods:

The researchers used Staphylococcus aureus 17810R cells starved of energy reserves and supplemented with glutamate or L-lactate. They measured substrate oxidation and ATP synthesis in whole cells and lysates. KCN was applied to determine which oxidases were involved in the process. CCCP was used to assess the effect of proton gradient disruption on oxidation rates. The study compared the P/O ratios of glutamate and L-lactate oxidation. NADH oxidation rates were measured in cell lysates to evaluate coupling efficiency. The authors also tested whether ATP synthesis was coupled to specific oxidases. These methods allowed them to distinguish between tightly and loosely coupled oxidation reactions.

Main Results:

The study found that L-lactate oxidation occurred via two terminal menaquinol oxidases: the ba3-type and the bo-type. Glutamate oxidation, in contrast, occurred only via the bo-type oxidase. ATP synthesis was coupled exclusively to the bo-type oxidase for both substrates. The P/O ratio for glutamate was 1.5, while for L-lactate it was 0.03. CCCP increased glutamate oxidation by 50% but had no effect on L-lactate oxidation. In lysates, NADH and L-lactate oxidation rates were equal. These findings suggest that glutamate oxidation is tightly coupled to ATP synthesis. L-lactate oxidation, however, appears loosely coupled in whole cells.

Conclusions:

The authors propose that two energy coupling sites may exist in the respiratory chain of strain 17810R. One is in the NADH-menaquinone oxidoreductase complex, and the other in the bo-type menaquinol oxidase complex. Glutamate oxidation is tightly coupled to ATP synthesis, while L-lactate oxidation is loosely coupled. The P/O ratios support this distinction in coupling efficiency. The bo-type oxidase is the primary site for ATP synthesis in whole cells. The study also suggests that the ba3-type oxidase is involved in L-lactate oxidation but not in ATP synthesis. The findings indicate that energy conservation mechanisms vary depending on the substrate. The authors conclude that the respiratory chain of S. aureus 17810R has distinct coupling sites for different substrates.

The study suggests two energy coupling sites: one in the NADH-menaquinone complex and one in the bo-type oxidase complex.

Lysate experiments showed equal NADH and L-lactate oxidation rates, indicating differences in coupling in whole cells.