TITLE:
Influence of Medicinal Spices on the Acid Tolerance of a Health Beneficial Bacterium Streptococcus thermophilus ST-M5
AUTHORS:
Margie M. Sánchez-Vega, Kayanush J. Aryana
KEYWORDS:
Spices; Garlic; Ginger; Onion; Acid Tolerance; Streptococcus thermophilus
JOURNAL NAME:
Open Journal of Medical Microbiology,
Vol.2 No.3,
September
26,
2012
ABSTRACT: There is a great deal of public interest in the use of herbal remedies. Garlic is said to antiviral and antifungal and along with ginger; they are antibacterial and preventatives for cardiovascular diseases. Ginger is very effective against nausea and has analgesic properties. Onion reduces the risk of developing diabetes and like garlic, has anticancer properties. Streptococcus thermophilus is a lactic acid bacterium that produces lactase, which facilitates the digestion of lactose in milk, decreases the symptoms of malabsorption, and reduces the risk of antibiotic associated diarrhea. Acid tolerance is an important probiotic characteristic and it is an indication of the ability of the microorganism to withstand the acidic pH of the stomach. Freshly thawed culture was inoculated in acidified MRS broth at pH 2 and 1% v/v of freshly ex-tracted spice juice was added. Control was without spice juice. Growth was determined hourly during 2 hours of incu-bation at 37?C. Bacterial culture treated with all three spices individually showed a significant increase in counts at 0 and 1 hours of incubation when compared to control. After 2 hours of incubation, culture exposed to ginger showed no significant difference compared to control, while there were slight yet significantly lower counts for culture exposed to garlic and onion individually. Among the spices, ginger had the best overall effect. These three spices can be used with Streptococcus thermophilus enabling health benefits from both sources.