Related Experiment Video
Updated: Apr 27, 2026
06:53
In Vivo Monitoring of Transcriptional Activity During Metabolic Transition Using a Bioluminescent Reporter in Yeast
Published on: February 21, 2025
942
Altered superoxide dismutase activity by carbohydrate utilization in a Lactococcus lactis strain
H Kimoto-Nira1, N Moriya2, H Ohmori2
1NARO Institute of Livestock and Grassland Science, Ikenodai 2, Tsukuba, Ibaraki 305-0901, Japan. anne@affrc.go.jp.
Journal of Food Protection
|July 3, 2014
Summary
Carbohydrate source significantly impacts superoxide dismutase (SOD) activity in Lactococcus lactis G50, influencing its fermentation pathways. Optimizing carbohydrate use can enhance the value of these bacteria in dairy products.
Area of Science:
- Microbiology
- Biochemistry
Background:
- Reactive oxygen species (ROS) cause cellular damage.
- Superoxide dismutase (SOD) enzymes neutralize superoxide radicals.
- Lactococci, used in dairy fermentation, possess SOD and may offer health benefits.
Purpose of the Study:
- To investigate the influence of different carbohydrate sources on SOD activity in Lactococcus lactis.
- To explore the relationship between carbohydrate metabolism and SOD activity.
- To determine strain-specific responses to carbohydrate availability.
Main Methods:
- Culturing Lactococcus lactis strains (G50 and H61) on various carbohydrates (lactose, galactose, glucose).
- Measuring SOD and NADH oxidase activities.
- Analyzing fermentation end products and growth efficiency under different conditions.
Main Results:
- Lactococcus lactis G50 exhibited higher SOD activity with lactose and galactose compared to glucose.
- SOD activity in Lactococcus lactis H61 was independent of the carbohydrate source.
- NADH oxidase activity in G50 correlated with SOD activity and carbohydrate type, showing highest activity on lactose.
- Strain G50 displayed mixed-acid fermentation on lactose and galactose, and homolactic fermentation on glucose; strain H61 predominantly used homolactic fermentation.
- Metabolic stress and aerobic conditions increased SOD activity in strain G50.
Conclusions:
- The impact of carbohydrate source on SOD activity in lactococci is strain-dependent.
- Enhanced SOD activity in Lactococcus lactis can be achieved through strategic carbohydrate selection favoring mixed-acid fermentation.
- Manipulating energy distribution and fermentation pathways offers a method to improve starter culture value and dairy product quality.
Related Concept Videos
01:25Inducible Operons: lac Operon
3.0K
The lac operon in Escherichia coli is a model for understanding inducible gene regulation and metabolic flexibility. It integrates local control by lactose and global regulation through catabolite repression, enabling E. coli to preferentially metabolize glucose when available and switch to lactose utilization when glucose is scarce.Structure and Function of the lac OperonThe lac operon contains three structural genes: lacZ (β-galactosidase), lacY (lactose permease), and lacA...
3.0K
01:20Fates of Pyruvate
9.0K
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...
9.0K
01:25Production of Organic Acids
105
Lactic acid, an important organic acid extensively applied in food, pharmaceutical, and biodegradable polymer industries, is primarily produced via microbial fermentation. This method is favored over chemical synthesis due to its environmental sustainability and capacity for enantiomerically pure product formation. Among various microbial processes, the fermentation of starch-based substrates stands out due to the abundance and renewability of raw materials like corn and potatoes.Hydrolysis of...
105
01:29Fermentation
96.5K
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...
96.5K
01:19Overview of Carbohydrate Metabolism
4.5K
Carbohydrate metabolism is a fundamental biochemical process that ensures a constant supply of energy to living cells. The most important carbohydrate is glucose, which can be broken down via glycolysis to enter into the Krebs cycle and eventually lead to the production of ATP through oxidative phosphorylation.
Glucose transport into cells is facilitated by a family of transport proteins called GLUT (Glucose Transporters). GLUT4 is the primary glucose transporter for insulin-stimulated glucose...
Glucose transport into cells is facilitated by a family of transport proteins called GLUT (Glucose Transporters). GLUT4 is the primary glucose transporter for insulin-stimulated glucose...
4.5K
01:27Microbes in the Production of Fermented Foods
324
Lactic acid bacteria (LAB) and molds are instrumental in fermenting plant-based foods to enhance preservation and ensure year-round availability. These microbial processes convert plant carbohydrates into organic acids and other metabolites that inhibit spoilage organisms and contribute to the sensory qualities of the final product.In sauerkraut production, cabbage goes through a microbial succession that starts with cocci such as Leuconostoc mesenteroides. These microbes begin fermentation by...
324