Related Experiment Video
Updated: Aug 10, 2025
06:58
Looking Outwards: Isolation of Cyanobacterial Released Carbohydrate Polymers and Proteins
Published on: May 27, 2019
6.6K
Probiotic Properties of Exopolysaccharide-Producing Bacteria from Natto
Vongsathorn Ngampuak1, Acharawan Thongmee1, Napapan Pongpoungphet2
1Microbiology Unit, Department of Biomedical Science, Faculty of Science, Rangsit University, Patumthani, Thailand.
International Journal of Food Science
|February 10, 2023
Summary
Researchers identified a promising probiotic strain, Bacillus subtilis VN5, from natto. This strain exhibits excellent survival under acidic and bile conditions, showing potential for gut health applications.
Area of Science:
- Microbiology
- Food Science
- Probiotics Research
Background:
- Natto, a fermented soybean food, is popular in Japan and Thailand.
- Screening for potential probiotic microorganisms from natto is a key area of research.
- Bacillus subtilis strain VN5 was isolated from natto for its high exopolysaccharide (EPS) production.
Purpose of the Study:
- To characterize the microbial exopolysaccharide (EPS) produced by Bacillus subtilis VN5.
- To evaluate the probiotic properties of Bacillus subtilis VN5.
- To assess the potential of Bacillus subtilis VN5 as a novel probiotic strain.
Main Methods:
- Fourier transform infrared (FT-IR) spectroscopy was used to analyze the EPS.
- Probiotic properties were tested, including resistance to lysozyme and acidic conditions.
- Survival rates in various bile salt concentrations were determined.
- Inhibition of pathogenic bacteria growth was assessed.
Main Results:
- FT-IR analysis indicated the presence of carboxyl and hydroxyl groups in the EPS, with patterns similar to levans.
- Bacillus subtilis VN5 demonstrated 90% resistance to lysozyme within 30 minutes.
- The strain survived across a wide pH range (1-6) and showed 100% survival in bile solutions (0.3-1%) for 24 hours.
- VN5 did not inhibit the growth of tested pathogenic bacteria (Escherichia coli, Staphylococcus aureus, Salmonella typhi).
- Gamma hemolysis was observed in the VN5 strain.
Conclusions:
- Bacillus subtilis strain VN5 possesses significant probiotic characteristics, including robust survival under challenging gastrointestinal conditions.
- The exopolysaccharide produced by VN5 warrants further investigation for its functional properties.
- While lacking direct antimicrobial activity against tested pathogens, VN5 shows high potential as a novel probiotic strain for the food industry.
Related Concept Videos
01:29Bacterial Flora of the Large Intestine
555
The gut microbiome is formed by a vast and diverse community of bacteria that colonizes our large intestine. These bacteria start residing in the gut from birth and continue diversifying throughout life, influenced by factors such as diet, lifestyle, and stress. The gut bacterial community also includes bacteria from food and those that enter the colon through the anus.
The normal gut flora of the colon plays a critical role in generating essential vitamins such as vitamins K, B5, and B7.
The normal gut flora of the colon plays a critical role in generating essential vitamins such as vitamins K, B5, and B7.
555
01:27Microorganisms in Agriculture and Food industry
134
Microorganisms play a crucial role in agriculture and the food industry, contributing to soil fertility, crop protection, and food production. Their functions range from nitrogen fixation and biopesticide production to fermentation and food preservation, making them indispensable to sustainable farming and food safety.Role in AgricultureNitrogen-fixing bacteria, such as Rhizobium (symbiotic) and Azotobacter (free-living), convert atmospheric nitrogen into ammonia through biological nitrogen...
134
01:30Bacterial Phylum Actinobacteria
59
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...
59
01:26Biosynthesis of Polysaccharides
49
Polysaccharides such as glycogen and starch are synthesized from nucleoside diphosphate sugars, primarily uridine diphosphate glucose (UDPG) and adenosine diphosphate glucose (ADPG). These activated glucose donors act as key intermediates in carbohydrate metabolism and biosynthesis. UDPG primarily involves glycogen synthesis in animals and many bacteria, while ADPG plays a fundamental role in starch synthesis in plants and certain bacteria.UDPG is formed when glucose-1-phosphate reacts with...
49
01:27Bacterial Phylum Firmicutes
77
Firmicutes is a diverse phylum of Gram-positive bacteria characterized by a low GC content in their genomes. This phylum includes organisms with monoderm or diderm cell envelopes, highlighting a complex evolutionary history. Firmicutes comprises several major orders, including Lactobacillales, Clostridiales, and Bacillales, which exhibit remarkable diversity in their morphology, metabolism, and ecological roles.The order Lactobacillales includes lactic acid bacteria, which are fermentative...
77
01:28Peptidoglycan Synthesis
128
Structure of PeptidoglycanPeptidoglycan is a vital structural component of the bacterial cell wall, providing mechanical strength and shape to the cell. It consists of repeating units of two sugars—N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)—linked by β-1,4 glycosidic bonds. These sugar chains are cross-linked by short peptide chains, forming a mesh-like polymer that surrounds the bacterial plasma membrane.Cytoplasmic Phase – Precursor SynthesisPeptidoglycan...
128