Browsing by Subject "Bacillus cereus"
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    Antibacterial activity of Chrysanthemum indicum, Centella asiatica and Andrographis paniculata on Bacillus cereus and Listeria monocytogenes under Low pH Stress
    ( 2012) Patchanee Yasurin ; Nateepat Pitinidhipat ; Christina Vania Utami
    Classic food preservation methods do not guarantee to inhibit Bacillus cereus and Listeria monocytogenes growth. The application of natural antibacterial agent is an alternative way to control their growth. Asia herbs, Chrysanthemum indicum, Centella asiatica, and Andrographis paniculata were used in this experiment to test their antibacterial activity under low pH stress. Their antibacterial activities of 95% ethanolic crude extracts were tested on B. cereus and L. monocytogenes 10403S under different low pH stress by agar disc diffusion method. The best antibacterial effect on both bacteria was found at low pH stress condition. Lowering pH also acts as one inhibitory effect. The result of in vitro antibacterial effect as inhibition zone at pH 7.0, 6.5, 6.0, 5.5, showed that the inhibition zone diameters of C. indicum extracts were 7.62±1.18. 7.87±2.35, 6.25±3.06 and 9.50±2.14 cm, while the inhibition zone diameters of C. asiatica extracts were 8.75±1.03, 8.75±2.66, 7.75±2.37 and 9.12±1.96 cm and A. paniculata extracts were 9.75±1.75, 5.87±3.52, 8.5±1.23 and 9.33±1.63 against L. monocytogenes 10403S, respectively. Under the same condition, the inhibition zone diameters of C. indicum extracts at 2.12±0.64, 1.37±0.92, 0.93±0.78 and 6.00±3.25 cm, the inhibition zone diameters of C. asiatica extracts at 0.62±0.44, 2.25±0.46, 1.75±0.28 and 6.50±1.60 cm and A. paniculata extracts at 0.87±0.79, 1.25±0.60, 2.00±1.65 and 6.00±1.31, respectively against B. cereus. All 95% ethanolic crude extracts showed more inhibition effect on L. monocytogenes 10403S than B.cereus. However, the promising active antibacterial compounds in all three herbs are needed to be identified. The MBCs of A. paniculata, C. asiatica and C. indicum showed 4, 16 and >32 µl/ml against B. cereus while A. paniculata and C. asiatica showed 16 and >32 µl/ml against L. monocytogenes 10403S.
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    Effect of extraction and shaking time on antibacterial activity of dry centella asiatica againts food pathogenic microorganisms
    (School of Biotechnology, Assumption University of Thailand, 2014-07) Patchanee Yasurin
    The outbreaks caused by pathogenic bacteria still being a major human health and food industry problem. Since time immemorial, people used plant material as medicine and nowadays, it widely used as tea preparation. Centella asiatica is a potential herbs related to its antibacterial activity. Therefore, this study aimed to investigate the antibacterial activity of dry C. asiatica crude 95% ethanolic extract under different extraction time (1, 3, 5, and 7 days) and shaking action (120 rpm) against three human pathogenic bacteria; Salmonella enterica typhimurium U302 (DT104b), S. enterica enteritidis (human), S. enteric 4, 5, 12:i:- (human) US clone, and Bacillus cereus by using agar disc diffusion method. The results showed that the all extracts showed antibacterial activity against B. cereus with inhibition zone range of 0.214 ± 0.053 to 0.557 ± 0.559 mm but has not significantly effect on Salmonella sp. The highest antibacterial activity of dry C. asiatica achieved on the three days extraction time. The shaking action could increase antibacterial activity. The MIC (minimum inhibitory concentration) was between 40-80 µl/ml and MBC (minimum bactericidal concentration) was 80-160 µl/ml. This showed that C. asiatica dry extract could inhibit gram-positive bacteria rather than gram-negative and shaking effect gives promising factor to increase effectiveness of plant ethanol extraction.
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    Effect of solvent and time extraction on antibacterial activity of Acacia concinna's pod against Bacillus cereus
    ( 2015-09) Patchanee Yasurin
    Herb extract becomes the great interesting functional ingredient. Acacia concinna -poi pod) is a potential herb as the functional ingredient. Therefore, this study aimed to investigate the effect of extraction solvent and time on antibacterial activity of dry A. concinna Bacillus cereus. The agar disc diffusion method was used to evaluate the antibacterial activity of A. concinna ts using Muller Hinton Agar media (MHA). The 20 g dry A. concinna solvents; water, 95% ethanol and hexane, for 1, 3 and 5 days at 120 rpm. Then dry A. concinna or at 70°C for water , 40°C for 95% ethanol and hexane then dilute to 20 µl/ml. The results showed that dry A. concinna extraction solvents in all extraction times. While dry s pod 95% ethanol crude extracts gave the lowest antibacterial activity. The dry A. concinna -hexane crude extracts gave the highest antibacterial activity; 0.89 ±0.07 cm. There are no statistically significant of antibacterial activity of A. concinna in all three extraction solvents. The results indicated that only extraction solvent affected the antibacterial activity of A. concinna for evaluate the Minimum inhibitory concentration (MIC) and the Minimum bactericidal concentration (MBC). The MIC was between 40-80 µl/ml and MBC was > 160 µl/ml. This showed that dry A. concinna t can be further applied to use in food industry, pharmaceutical and cosmetic.