Moringa oleifera, Lam. (Moringaceae) is grown world-wide in the tropics and sub-tropics of Asia and Africa and contains abundant various nutrients. This study describes the effect of different parts (leaf, stem and stalk) and seasons (summer and winter) on the chemical compositions and antioxidant activity of M. oleifera grown in Taiwan. The results showed that the winter samples of Moringa had higher ash (except the stalk part), calcium and phenolic compounds (except the leaf part) and stronger antioxidative activity than summer samples. The methanolic extract of Moringa showed strong scavenging effect of DPPH radicals and reducing power. The trend of antioxidative activity as a function of the part of Moringa was: leaf > stem > stalk for samples from both seasons investigated. The Moringa extract showed strong hydrogen peroxide scavenging activity and high Superoxide Dismutase (SOD) activity except the stalk part.

Aims: To find the cause of misidentification of aeromonads when using the Vitek system. Methods and Results: Two Aeromonas veronii biovar sobria isolates were misidentified as Vibrio alginolyticus by the Vitek system. Both strains' identification was confirmed by biochemical testing, API 20E/20NE kits and/or 16S RFLP analysis. Thirty-one known Aeromonas species were tested by the Vitek system using 0AE45 and 0AE85% saline in the suspension medium. It was not clear whether low salinity causes misidentification of Aeromonas species more frequently. Conclusions: The specified reaction time may be inappropriately short for some critical biochemical tests of some strains. An ingenious reading strategy regarding incubation time is necessary to improve identification of Aeromonas species by the Vitek system. Significance and Impact of the Study: To our knowledge, this is the first report of misidentification of A. veronii biovar sobria as V. alginolyticus in the Vitek system.

Propolis originates from a resinous substance collected by honeybees from the buds and leaves of trees and plants, which is then mixed with pollen as well as enzymes secreted by the bees. In the present study, the susceptibility of Listeria monocytogenes to the ethanol extract of propolis (EEP) as influenced by EEP concentration, incubation temperature, pH, and cell age was investigated. In addition, the antimutagenic action of EEP against 4-nitroquinoline-N-oxide (4-NQO) was also examined. Results revealed that EEP at a dosage of 7.5 µg mL −1 or higher exerted a bactericidal effect on L. monocytogenes. L. monocytogenes was most susceptible to EEP at 37 • C followed by 25 and 4 • C. At acid pH values, cells of the test organism were more sensitive to EEP than at neutral pH, while most resistant at alkaline pH values. Cell age was also found to affect the susceptibility of L. monocytogenes to EEP. Cells in the mid-exponential phase showed the highest susceptibility, followed by cells in the late-exponential phase and stationary phase. EEP caused cell leakage of the test organism. A marked increase in the absorbance at 260 nm, UV-absorbing material in the supernatant of cell suspension, and irregularly shaped materials around the cell surface were noted after cells of L. monocytogenes were exposed to EEP. Furthermore, EEP at a dosage of 7.5-60.0 µg per plate was found to suppress 4-NQO-induced mutation by 17.6-88.8%.

In the present study, the ethanol extract of propolis (EEP) collected in Taiwan was prepared and assayed for the effects concentration, incubation temperature, pH and cell age on the antimicrobial activity against Streptococcus mutans, a dental cavitycausing oral pathogen. Additionally, cell leakage of Str. mutans in presence of EEP was also examined.It was found EEP exerted bacteriostatic and bactericidal effects against Str. mutans, respectively, at concentrations of 1.875 and 3.75 µg/mL or more. At 37°C, Str. mutans was more sensitive to EEP than at 25°C while most resistant at 4°C. Cells of test organism were most susceptible to EEP at acid pH followed by neutral and alkaline pH. It was also noted that cells of Str. mutans in the stationary phase were more resistant, while cells in the mid-exponential phase were more susceptible to EEP. After exposure to EEP, a marked increase in the 260 nm absorbance for the supernatant of culture, was observed, indicating the release of UV-absorbing materials. Scanning electron micrographs also showed an increase in material with irregular shape on the surface of EEP-treated Str. mutans cells.

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