Aims:This study was carried out to optimize the fermentation conditions using statistical approach for polyhydroxyalkanoate(PHA) production by a local isolate, Burkholderia cepaciaBPT1213, in the shake flask system.Methodology and results:Throughout this study, B. cepaciaBPT1213 was grown in minimal salt medium (MSM) supplemented with 2% of waste glycerol (86.70% purity).The strain can produce up to 1.33 g/L cell dry weight (CDW) with 22.21% of PHA content, thus giving a total PHA concentration 0.30 g/L before optimization. A factorial design experiment that was carried out showed all parameters KH2PO4, Na2HPO4·2H2O, carbon-to-nitrogen ratio (C/N), initial pH of medium, and temperature significantly affected the growth (cell dry weight, CDW) and PHA content. Response surface methodology (RSM) using central composite design (CCD) was then applied to optimize these parameters. The optimum conditions suggested were at 2.5 g/L KH2PO4, 4.5 g/L Na2HPO4·2H2O, 30 (g/g) C/N ratio, initial medium pH of 8.5 and 37 °C cultivation temperature, with a predicted CDW of 3.43 g/L and PHA content of 45.71% contributing to 1.57 g/L total PHA concentration. The verification experiment resulted in 3.60 g/L of CDW with 48.08% of PHA content contributing to 1.73 g/L total PHA concentration.Conclusion, significance and impact of study:The statistical approach using factorial design and RSM have succeeded in increasing the production of PHA by B. cepaciaBPT1213 using waste glycerol as the sole carbon source which is a promising renewable and cheaper feedsto

An efficient public health preparedness and response plan for infectious disease management is important in recent times when emerging and exotic diseases that hitherto were not common have surfaced in countries with potential to spread outside borders. Stewardship from a reference laboratory is important to take the lead for the laboratory network, to proactively set up disease surveillance, provide referral diagnostic services, on-going training and mentorship and to ensure coordination of an effective laboratory response. In Malaysia, the Institute for Medical Research has provided the stewardship for the Ministry of Health's laboratory network that comprises of hospital pathology, public health and university laboratories. In this paper we share our experiences in recent infectious disease outbreak investigations as a reference laboratory within the Ministry of Health infectious disease surveillance network.

Background: Clausine B, a carbazole alkaloid isolated from the stem bark of Clausena excavata, was investigated for its antiproliferative activities against five human cancer cell lines: HepG2 (hepatic cancer), MCF-7 (hormone-dependent breast cancer), MDA-MB-231 (non-hormone-dependent breast cancer), HeLa (cervical cancer), and CAOV3 (ovarian cancer). Methods: Chang liver (normal cells) was used as a control. The effect of clausine-B was measured using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Results: Clausine-B was found to be active (IC50<30 μg/mL) against four of the cancer cell lines tested. The IC50 values for these four lines were: 21.50 μg/mL (MDA-MB-231), 22.90 g/ml (HeLa), 27.00 μg/mL (CAOV3) and 28.94 μg/mL (HepG2). Clausine-B inhibited the MCF-7 cancer cell line at 52.90 μg/mL, and no IC50 value was obtained against Chang liver. Conclusion: It is possible that the phenolic group in clausine-B responsible for the antiproliferative activities found in this study.