Prodigiosin - an antibacterial red pigment produced by Serratia marcescens IBRL USM 84 associated with a marine sponge Xestospongia testudinaria.

The objectives of present study are to extract the antibiotic compound from marine isolate and to determine its in vitro antimicrobial activity against bacteria. A marine bacterial isolate Serratia marcescens IBRL USM 84 was isolated from the surface of a marine sponge Xestospongia testudinaria. This species of bacteria produced red pigment with antibacterial activity. The red antibacterial pigment was produced intracellularly and inhibited 13 out of 18 tested bacteria, with Gram positive was more susceptible than the Gram negative bacteria. The growth and antibacterial red pigment production profiles demonstrated the highest antibacterial red pigment production was achieved at the 48 hours of cultivation (14.08 U/ml) time in marine broth when incubated at 25 °C with 150 rpm agitation. The antibacterial red pigment was extracted, purified and confirmed as prodigiosin.

Efficacy of pyroligneous acid from Rhizophora apiculata on pathogenic Candida albicans.

Rhizophora apiculata pyroligneous acid which is a crude condensate produced from the distillation of smoke generated in the process of charcoal making has the potential to be used as antifungal agent especially to treat candidal infections. In this study, pyroligneous acid (PA), concentrated pyroligneous acid (CPA), Dichloromethane extracts of CPA namely DCM A and B were tested against four pathogenic strains of Candida albicans. The results exhibited significant inhibition zones within the range of 7.00 -8.00 mm for PA, 16.00- 17.00 mm for CPA, 16.00-18.00 mm for DCM A and 19.00-22.00 mm for DCM B. The results also revealed that extract DCM B of CPA was the most potential to be used as anticandidal agent with the minimum inhibitory concentration values between 3.13-6.25 mg/mL. Scanning electron micrographs of DCM B treated C. albicans cells confirmed the damaged cells caused by the extract.

Pharmacological screening of methanolic extract of Ixora species

<p><b>OBJECTIVE</b>To investigate the antimicrobial activity of methanolic extracts of different parts of Ixora species.</p><p><b>METHODS</b>Antimicrobial activity was carried out using disc diffusion assay against fungi, gram-positive and gram-negative bacteria.</p><p><b>RESULTS</b>All methanolic extracts of different parts of Ixora species showed a broad-spectrum of antibacterial and antiyeast activities, which inhibited the growth of at least one bacterium or yeast. There was no remarkable difference between different Ixora species observed in this study.</p><p><b>CONCLUSIONS</b>The significant antimicrobial activity shown by this Ixora species suggests its potential against infections caused by pathogens. The extract may be developed as an antimicrobial agent.</p>

Gallic acid: An anticandidal compound in hydrolysable tannin extracted from the barks of Rhizophora apiculata Blume.

A research was conducted to study the anticandidal compound of tannin extracted from the barks of a mangrove tree, Rhizophora apiculata Blume. Tannin obtained from the barks of Rhizophora apiculata Blume was further separated into condensed and hydrolysable tannins. A strong anticandidal activity was detected in the hydrolysable tannin, which exhibited minimal inhibitory concentration (MIC) of 6.25 mg/ml, and it was found to have yeastostatic activity at lower concentration (below MIC value) and yeastocidal activity at higher concentration (more than the MIC value). Furthermore, the isolation of the bioactive compound in hydrolysable tannin that responsible for the anticandidal activity was also determined using thin layer chromatography and high-performance liquid chromatography (HPLC). The results obtained confirmed that gallic acid was the bioactive compound that plays role in inhibiting and killing the Candida albicans cells.