Identification and Characterization of The Causal Agent of Infected Iceberg Lettuce (Lactuca Sativa L.) in Perak, Malaysia

Lack of knowledge about the causal agent of infected crops lead farmers to use wrong treatment on their crops, which is causing negative effects on environment and human’s health. This study was conducted to identify and characterize the causal agent from the infected iceberg lettuce (Lactuca sativa L.) in Perak, Malaysia. The infected iceberg lettuces were sampling from Perak area and the causal agent was isolated by direct plating technique on a nutrient medium. The isolated bacteria were identified by molecular method and biochemical test. Molecular identification was carried out using 16S rRNA sequence and then, several tests such as amylase, catalase, oxidase and others were done for identification of bacterial species based on their biochemical activities. The obtained results showed that Serratia marcescenes and Stenotrophomonas sp. were identified as the causal agents. The pathogenicity has been confirmed by the establishment of Koch’s Postulate, which showed 100% disease infection on them. The environmental effects also have been tested on the bacteria to study the ability of bacteria to grow in different environmental conditions based on different in pH, salinity, and temperature. All the bacterial sample showed that they able to growth on the pH between 4.0 to 9.0, at the temperature 10 °C to 45 °C and at the addition salinity to the medium between 2.5 %, 5.0% and 7.5 %. Keywords: Stenotrophomonas sp., Serratia sp., lettuce, lettuce diseas

Molecular Identification of Isolated Fungi from Kelantan and Terengganu Using Internal Transcriber Spacer (ITS) Region

Fungi are morphologically, ecologically, metabolically and phylogenetically diverse. Fungi play important roles as one of the major decomposer in ecosystems, dominated by Saprophytic fungi. The identification of fungi is important to differentiate each fungi owing to their special ability in our ecosystem. However, the identification of fungi is become very challenging for those untrained mycologists.  Essentially, the identification of fungi at the species-level is more problematic. Traditional approaches, based on the morphological or physiological features alone are unreliable because of the limited amount of morphological characters for fungi identification. Thus, a reliable molecular approach is required to identify the fungi at species-level. Here, we have successfully identified the species of 25 isolated fungi samples from the polluted areas in Kelantan and Terengganu by using the molecular identification utilizing the ITS1-5.8S-ITS2 regions. Phylogenetics tree was then constructed, using MEGA v7.0 software to illustrate the inter-relationships among the isolates. Among of 25 isolated fungi samples, 23 were identified from Ascomycota division and another two were from the Zygomycota division. From our observation, the most frequent species grew for both polluted areas were from Lasiodiplodia sp

Assessing indoor air quality using chemometric models

The objectives of this study are to identify the significant variables and to verify the best statistical method for determining the effect of indoor air quality (IAQ) at 7 different locations in Universiti Sultan Zainal Abidin, Terengganu, Malaysia. The IAQ data were collected using in-situ measurement. Principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), linear discrimination analysis (LDA), and agglomerative hierarchical clustering (AHC) were used to classify the significant variables as well as to compare the best method for determining IAQ levels. PCA verifies only 4 out of 9 parameters (PM10, PM2.5, PM1.0, and O3) and is the significant variable in IAQ. The PLS-DA model classifies 89.05% correct of the IAQ variables in each station compared to LDA with only 66.67% correct. AHC identifies three cluster groups, which are highly polluted concentration (HPC), moderately polluted concentration (MPC), and low-polluted concentration (LPC) area. PLS-DA verifies the groups produced by AHC by identifying the variables that affect the quality at each station without being affected by redundancy. In conclusion, PLS-DA is a promising procedure for differentiating the group classes and determining the correct percentage of variables for IAQ

Determination of selected heavy metals in airborne particles in industrial area: a baseline study

This study focuses on airborne heavy metal pollution in the industrial area. Eight points from Paka and Gebeng Industrial Area respectively were selected for this study within two monsoon seasons. The samples were analysed for heavy metals (Cd, As, Cu, Fe, Ni, Pb, and Zn) by using inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the mean concentration value of As, Pb and Cd for Paka were 0.005 mg/L ± 0.001, 0.107 mg/L ± 0.088, and 0.010 mg/L ± 0.008, respectively and Gebeng were 0.004 mg/L ± 0.002, 0.069 mg/L ± 0.059 and 0.005 mg/L ± 0.004, respectively in the southwest monsoon - much higher than the target value by European Commission in Directive 2004/107/EC and Directive 2008/50/EC. It could be concluded that the industrial and transportation emission were the major source of heavy metals in the atmosphere along the Paka and Gebeng Industrial Area

Regulation of Apoptotic Effects by Erythrocarpine E, a Cytotoxic Limonoid from Chisocheton erythrocarpus in HSC-4 Human Oral Cancer Cells

The aim of this study was to determine the cytotoxic and apoptotic effects of erythrocarpine E (CEB4), a limonoid extracted from Chisocheton erythrocarpus on human oral squamous cell carcinoma. Based on preliminary dimethyl-2-thiazolyl-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays, CEB4 treated HSC-4 cells demonstrated a cytotoxic effect and inhibited cell proliferation in a time and dose dependent manner with an IC50 value of 4.0±1.9 µM within 24 h of treatment. CEB4 was also found to have minimal cytotoxic effects on the normal cell line, NHBE with cell viability levels maintained above 80% upon treatment. Annexin V-fluorescein isothiocyanate (FITC), poly-ADP ribose polymerase (PARP) cleavage and DNA fragmentation assay results showed that CEB4 induces apoptosis mediated cell death. Western blotting results demonstrated that the induction of apoptosis by CEB4 appeared to be mediated through regulation of the p53 signalling pathway as there was an increase in p53 phosphorylation levels. CEB4 was also found to up-regulate the pro-apoptotic protein, Bax, while down-regulating the anti-apoptotic protein, Bcl-2, suggesting the involvement of the intrinsic mitochondrial pathway. Reduced levels of initiator procaspase-9 and executioner caspase-3 zymogen were also observed following CEB4 exposure, hence indicating the involvement of cytochrome c mediated apoptosis. These results demonstrate the cytotoxic and apoptotic ability of erythrocarpine E, and suggest its potential development as a cancer chemopreventive agent

Identification and Characterization of The Causal Agent of Infected Iceberg Lettuce (Lactuca Sativa L.) in Perak, Malaysia.

Lack of knowledge about the causal agent of infected crops lead farmers to use wrong treatment on their crops, which is causing negative effects on environment and human’s health. This study was conducted to identify and characterize the causal agent from the infected iceberg lettuce (Lactuca sativa L.) in Perak, Malaysia. The infected iceberg lettuces were sampling from Perak area and the causal agent was isolated by direct plating technique on a nutrient medium. The isolated bacteria were identified by molecular method and biochemical test. Molecular identification was carried out using 16S rRNA sequence and then, several tests such as amylase, catalase, oxidase and others were done for identification of bacterial species based on their biochemical activities. The obtained results showed that Serratia marcescenes and Stenotrophomonas sp. were identified as the causal agents. The pathogenicity has been confirmed by the establishment of Koch’s Postulate, which showed 100% disease infection on them. The environmental effects also have been tested on the bacteria to study the ability of bacteria to grow in different environmental conditions based on different in pH, salinity, and temperature. All the bacterial sample showed that they able to growth on the pH between 4.0 to 9.0, at the temperature 10 °C to 45 °C and at the addition salinity to the medium between 2.5 %, 5.0% and 7.5 %

7 alpha-Hydroxy-beta-Sitosterol from Chisocheton tomentosus Induces Apoptosis via Dysregulation of Cellular Bax/Bcl-2 Ratio and Cell Cycle Arrest by Downregulating ERK1/2 Activation

In continuation of our interest towards the elucidation of apoptotic pathways of cytotoxic phytocompounds, we have embarked upon a study on the anticancer effects of 7 alpha-hydroxy-beta-sitosterol (CT1), a rare natural phytosterol oxide isolated from Chisocheton tomentosus. CT1 was found to be cytotoxic on three different human tumor cell lines with minimal effects on normal cell controls, where cell viability levels were maintained >= 80 upon treatment. Our results showed that cell death in MCF-7 breast tumor cells was achieved through the induction of apoptosis via downregulation of the ERK1/2 signaling pathway. CT1 was also found to increase proapoptotic Bax protein levels, while decreasing anti-apoptotic Bcl-2 protein levels, suggesting the involvement of the intrinsic pathway. Reduced levels of initiator procaspase-9 and executioner procaspase-3 were also observed following CT1 exposure, confirming the involvement of cytochrome c-mediated apoptosis via the mitochondrial pathway. These results demonstrated the cytotoxic and apoptotic ability of 7 alpha-hydroxy-beta-sitosterol and suggest its potential anti-cancer use particularly on breast adenocarcinoma cells

Chemical structure of erythrocarpine E (CEB4) extracted from <i>Chisocheton erythrocarpus.</i>

<p>Chemical structure of erythrocarpine E (CEB4) extracted from <i>Chisocheton erythrocarpus.</i></p

Modulation of p53 signalling and p53-related apoptotic protein levels by CEB4 on HSC-4 oral cancer cells.

<p>Cells were incubated with CEB4 for 6 and 12 h, harvested in lysis buffer and subjected to SDS-PAGE. Protein expression levels were examined by Western blot analysis and quantified using the ImageJ software employing β-actin as a normalization control. (<b>A</b>) Analysis of p53 and MDM2 inhibitor levels. (<b>B</b>) Analysis of anti-apoptotic Bcl-2 and pro-apoptotic Bax protein levels. (<b>C</b>) Analysis of initiator procaspase-9 and effector caspase-3 zymogen levels. Quantification of normalized protein levels against β-actin are shown on right panels.</p