Antimicrobial activity against methicillin-resistant Staphylococcus aureus in the culture broth of Enterococcus faecalis TH10, an isolate from Malaysian fermentation food, Temph.
The substance that produced by Enterococcus faecalis TH10 showed a great antibacterial activity against methicillin resistant staphylococcus aureus (MRSA)
Japanese Journal of Dairy and Food Science. 45 (1996)
We examined antibacterial activities of
Enterococcus faecalis TH10 against methicillin-resistant Staphylococcus
aureus (MRSA) which is known as a bacterium causing nosocomial infection.
We extracted culture supernatant fluids of Enterococcus faecalis TH10. We prepared the extract apt for the test
and performed an antibacterial test with a paper disk method.
extract from culture supernatant fluids of Enterococcus
faecalis TH10 showed a potent antibacterial activity against MRSA and a
modest antibacterial activity against methicillin-sensitive Staphylococcus aureus. No antibacterial
activity was observed in Enterococcus
genus. We considered that Enterococcus
faecalis TH10 is different from
bacteriocin which shows antibacterial activity against the related
species of lactic acid bacteria.
Effect of cultural conditions on the fumarate metabolism in Lactobacillus delbrueckii.
Case：Identification of LAB
The investigation of the cultural conditions which affect to the fumarate metabolism by 3 strains of Lactobacillus delbrueckii
Journal of Food Science and Technology. 41, 469-474 (1994)
Organic acids which microorganisms
produce play an important role to add flavor and acidity to fermented foods. However, the degree
of acidity and quality varies based on each organic acid. When the balance
between the acidity and quality of organic acids is improper, the taste becomes
bad. There were not many studies about fumarase, one of the lactic acid
bacteria which transforms fumaric acid to L-malate. In this study, we examined the cultural conditions which affect
to the fumarate metabolism by 3 strains of Lactobacillus delbrueckii.
We determined the quantity of organic
acids in the culture fluid. We filtrated bacterial bodies and measure the
filtrate with high-performance liquid chromatography. The degree of bacterial
growth was evaluated by optical density with 660 nm.
Bacterial growth was promoted by applying fumaric acid
to mediums based on the examination about medium compositions. We also examined
the effect of metal-ion to the fumarate
metabolic potential. The fumarate
metabolic potential was enhanced in the culture added Mg2+, but it was
suppressed in the culture added Cu2+. The transformation from fumaric acid to L-malate among these 3 strains associated with their growth and its
maturity rate did not change either in static culture or shaking culture.
Screening for lactic acid bacteria transforming fumarate to L-malate and some properties of selected strains.
Case：Identification of LAB
Screening for lactic acid bacteria with L-malate formation potential and examining its properties
Journal of Food Science and Technology. 40, 316-322 (1993)
L-malate is one kind of organic
acid which microorganisms produce. It plays an important role not only for
fermented foods but also for the compounds to add flavor and acidity to
juice and soft drinks. We compared the capabilities
of transforming fumaric acid to L-malate among various strains of lactic acid bacteria.
We determined the production of L-malate by the enzymatic method in the reaction mixtures which
consisted of the suspensions containing each sample strain and fumaric acid. The
optimal pH, incubation temperature and sodium chloride concentration were also
Many strains that have a great
potential belonged to Lactobacillus.
Optimal pH at the transformation
from fumaric acid to L-malate among Lactobacillus
delbrueckii subsp. lactis 1135 and Lactobacillus
delbrueckii subsp.bulgaricus 7235 was pH 7 and pH 6. Both
strains demonstrated great L-malate formation
properties in the range of 30 to 45 degree C. The highest L-malate production of lactis 1135 and bulgaricus 7235
was measured when the sodium chloride
concentration was 10% and3%.