Related Experiment Video
Updated: Mar 7, 2026
06:17
Medium Preparation for the Cultivation of Microorganisms under Strictly Anaerobic/Anoxic Conditions
Published on: August 15, 2019
30.1K
Production of propionic acid by mixed bacterial fermentation
P M Border1, M P J Kierstan1, G S Plastow1
1Dalgety PLC, Group Research Laboratory, CB1 2JN, Cambridge, England.
Biotechnology Letters
|March 2, 2017
Summary
Researchers optimized propionic acid production using a mixed culture of Propionibacterium freudenreichii ssshermanii and Lactobacillus amylophilus. This method achieved high yields of propionic acid suitable for food preservation.
Area of Science:
- Microbiology
- Biotechnology
- Food Science
Background:
- Propionic acid is a valuable organic acid with applications in food preservation.
- Optimizing fermentation conditions is crucial for efficient propionic acid production.
- Starch-based media offer a sustainable substrate for microbial fermentation.
Purpose of the Study:
- To identify optimal conditions for propionic acid production by various Propionibacteria and Lactobacilli.
- To evaluate pure and mixed culture systems for enhanced propionic acid yields.
- To develop a cost-effective method for producing food-grade propionic acid.
Main Methods:
- Cultivation of Propionibacteria and Lactobacilli in starch-based media.
- Comparison of pure and mixed culture fermentation performance.
- Optimization of growth parameters for propionic acid synthesis.
- Processing of fermentation broths to isolate and concentrate propionic acid.
Main Results:
- A mixed culture of Propionibacterium freudenreichii ssshermanii and Lactobacillus amylophilus demonstrated superior performance.
- The optimized system yielded approximately 20 g/l of propionic acid from a wheat flour and corn steep liquor medium.
- Simple processing of fermentation broths resulted in a product with approximately 30% (w/w) propionic acid.
Conclusions:
- The identified mixed culture system is highly effective for propionic acid production.
- The produced propionic acid concentration is suitable for potential use as a food preservative.
- This study presents a promising biotechnological approach for sustainable propionic acid manufacturing.
Related Concept Videos
01:23Microbial Fermentation
1.7K
Fermentation is a crucial anaerobic metabolic process that enables microbes to derive energy from sugar without relying on oxygen or an electron transport chain. This process is fundamental to various biological and industrial applications and is classified based on the metabolic products generated.Role of Pyruvate in FermentationPyruvate and its derivatives serve as key electron acceptors in fermentative pathways. The oxidation of NADH to regenerate NAD+ is essential for the continuation of...
1.7K
01:20Fates of Pyruvate
11.8K
Pyruvate is the end product of glycolysis, where glucose is oxidized to pyruvate, simultaneously reducing NAD+ to NADH. Two molecules of ATP are also produced by substrate-level phosphorylation.
In aerobic organisms, pyruvate is metabolized via the citric acid cycle to produce reduced coenzymes NADH and FADH2. These coenzymes are then oxidized in the electron transport chain to produce ATP and, in the process, regenerate the NAD+ and FAD. As seen in some cell types and organisms, fermentation...
In aerobic organisms, pyruvate is metabolized via the citric acid cycle to produce reduced coenzymes NADH and FADH2. These coenzymes are then oxidized in the electron transport chain to produce ATP and, in the process, regenerate the NAD+ and FAD. As seen in some cell types and organisms, fermentation...
11.8K
01:29Fermentation
132.0K
Most eukaryotic organisms require oxygen to survive and function adequately. Such organisms produce large amounts of energy during aerobic respiration by metabolizing glucose and oxygen into carbon dioxide and water. However, most eukaryotes can generate some energy in the absence of oxygen by anaerobic metabolism.
Fermentation is a type of metabolic process that occurs in the absence of oxygen, where organic molecules such as glucose are broken down to produce energy. During this process, the...
Fermentation is a type of metabolic process that occurs in the absence of oxygen, where organic molecules such as glucose are broken down to produce energy. During this process, the...
132.0K
01:30Bacterial Phylum Actinobacteria
778
Coryneform bacteria are gram-positive, aerobic, nonmotile rods that exhibit irregular, club-shaped, or V-shaped arrangements. Their V-shape results from snapping division, where the inner cell wall layer forms the cross-wall, while the outer layer remains intact until it ruptures on one side, causing the daughter cells to bend away.The primary genera are Corynebacterium and Arthrobacter. Corynebacterium includes diverse species, ranging from saprophytes to pathogens like Corynebacterium...
778
01:26Respiration Pathways
844
Cellular respiration is a fundamental metabolic process that enables organisms to generate energy from organic molecules. One of its central pathways is the tricarboxylic acid (TCA) cycle, also known as the Krebs cycle, which plays a crucial role in energy production and biosynthetic processes.Conversion of Pyruvate to Acetyl-CoAThe pyruvate generated from glycolysis undergoes oxidative decarboxylation by the pyruvate dehydrogenase complex, producing acetyl-CoA, one molecule of NADH, and one...
844
01:18Amino Acid Catabolism
1.5K
Microorganisms rely on proteins as an essential carbon and energy source, particularly in environments with limited polysaccharides or lipids. However, proteins are too large to cross the plasma membrane unaided, necessitating enzymatic degradation. Microbes secrete extracellular proteases and peptidases that hydrolyze proteins into peptides, which can then be transported across the membrane. Once inside the cell, intracellular proteases degrade these peptides into free amino acids, which...
1.5K