Characterization of Bacillus subtilis strains in Thua nao, a traditional fermented soybean food in northern Thailand.
OBJECTIVE
To clarify the diversity of Bacillus subtilis strains in Thua nao that produce high concentrations of products useful in food manufacturing and in health-promoting compounds.


RESULTS
Production of amylase, protease, subtilisin NAT (nattokinase), and gamma-polyglutamic acid (PGA) by the Bacillus subtilis strains in Thua nao was measured. Productivity of protease NAT by these strains tended to be higher than by Japanese commercial natto-producing strains. Molecular diversity of isolated strains was analysed via randomly amplified polymorphic DNA-PCR fingerprinting. The strains were divided into 19 types, including a type with the same pattern as a Japanese natto-producing strain.


CONCLUSIONS
B. subtilis strains that could be a resource for effective production of protease, amylase, subtilisin NAT, or PGA were evident in Thua nao produced in various regions in northern Thailand.


CONCLUSIONS
This study clearly demonstrated the value of Thua nao as a potential resource of food-processing enzymes and health-promoting compounds.
Inatsu
Y
Y
National Food Research Institute, Tsukuba, Japan. inatu@affrc.go.jp
Nakamura
N
N
Yuriko
Y
Y
Fushimi
T
T
Watanasiritum
L
L
Kawamoto
S
S
D000681:Amylases / Q000032:analysis / Q000235:genetics; D001412:Bacillus subtilis / Q000145:classification* / Q000201:enzymology* / Q000302:isolation & purification; D005285:Fermentation; D010447:Peptide Hydrolases / Q000032:analysis / Q000235:genetics; D010802:Phylogeny; D011099:Polyglutamic Acid / Q000031:analogs & derivatives / Q000032:analysis / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D013025:Glycine max / Q000382:microbiology*; D013381:Subtilisins / Q000032:analysis / Q000235:genetics; D013785:Thailand
C511775:poly(gamma-glutamic acid); D011099:Polyglutamic Acid; D000681:Amylases; D010447:Peptide Hydrolases; D013381:Subtilisins; C053771:nattokinase