Performance and microbial diversity of palm oil mill effluent microbial fuel cell

Aim: To evaluate the bioenergy generation and the microbial community structure from palm oil mill effluent using microbial fuel cell. Methods and Results: Microbial fuel cells enriched with palm oil mill effluent (POME) were employed to harvest bioenergy from both artificial wastewater containing acetate and complex POME. The microbial fuel cell (MFC) showed maximum power density of 3004 mW m^?2 after continuous feeding with artificial wastewater containing acetate substrate. Subsequent replacement of the acetate substrate with complex substrate of POME recorded maximum power density of 622 mW m^?2. Based on 16S rDNA analyses, relatively higher abundance of Deltaproteobacteria (88·5%) was detected in the MFCs fed with acetate artificial wastewater as compared to POME. Meanwhile, members of Gammaproteobacteria, Epsilonproteobacteria and Betaproteobacteria codominated the microbial consortium of the MFC fed with POME with 21, 20 and 18·5% abundances, respectively. Conclusions: Enriched electrochemically active bacteria originated from POME demonstrated potential to generate bioenergy from both acetate and complex POME substrates. Further improvements including the development of MFC systems that are able to utilize both fermentative and nonfermentative substrates in POME are needed to maximize the bioenergy generation. Significance and Impact of the Study: A better understanding of microbial structure is critical for bioenergy generation from POME using MFC. Data obtained in this study improve our understanding of microbial community structure in conversion of POME to electricity.     

New antiplasmodial indole alkaloids from Hunteria zeylanica

Two new indole alkaloids, bisnicalaterine D (1), consisting of an eburnane and a corynanthe type of skeletons, and nicalaterine A (2) were isolated from the bark of Hunteria zeylanica. Their structures were elucidated by various spectroscopic data such as NMR and CD spectra. A series of bisnicalaterines and nicalaterine A showed potent antiplasmodial activity against Plasmodium falciparum 3D7.     

Ethnic differences in survival after breast cancer in South East Asia

Background

The burden of breast cancer in Asia is escalating. We evaluated the impact of ethnicity on survival after breast cancer in the multi-ethnic region of South East Asia.

Methodology/Principal Findings

Using the Singapore-Malaysia hospital-based breast cancer registry, we analyzed the association between ethnicity and mortality following breast cancer in 5,264 patients diagnosed between 1990 and 2007 (Chinese: 71.6%, Malay: 18.4%, Indian: 10.0%). We compared survival rates between ethnic groups and calculated adjusted hazard ratios (HR) to estimate the independent effect of ethnicity on survival. Malays (n = 968) presented at a significantly younger age, with larger tumors, and at later stages than the Chinese and Indians. Malays were also more likely to have axillary lymph node metastasis at similar tumor sizes and to have hormone receptor negative and poorly differentiated tumors. Five year overall survival was highest in the Chinese women (75.8%; 95%CI: 74.4%–77.3%) followed by Indians (68.0%; 95%CI: 63.8%–72.2%), and Malays (58.5%; 95%CI: 55.2%–61.7%). Compared to the Chinese, Malay ethnicity was associated with significantly higher risk of all-cause mortality (HR: 1.34; 95%CI: 1.19–1.51), independent of age, stage, tumor characteristics and treatment. Indian ethnicity was not significantly associated with risk of mortality after breast cancer compared to the Chinese (HR: 1.14; 95%CI: 0.98–1.34).

Conclusion

In South East Asia, Malay ethnicity is independently associated with poorer survival after breast cancer. Research into underlying reasons, potentially including variations in tumor biology, psychosocial factors, treatment responsiveness and lifestyle after diagnosis, is warranted.     

Monoterpene Alcohol Metabolism: Identification, Purification, and Characterization of Two Geraniol Dehydrogenase Isoenzymes from Polygonum minus Leaves

NADP(+)-dependent geraniol dehydrogenase (EC 1.1.1.183) is an enzyme that catalyzes the oxidation of geraniol to geranial. Stable, highly active cell-free extract was obtained from Polygonum minus leaves using polyvinylpolypyrrolidone, Amberlite XAD-4, glycerol, 2-mercaptoethanol, thiourea, and phenylmethylsulfonylfluoride in tricine-NaOH buffer (pH 7.5). The enzyme preparation was separated into two activity peaks, geraniol-DH I and II, by DEAE-Toyopearl 650M column chromatography at pH 7.5. Both isoenzymes were purified to homogeneity in three chromatographic steps. The geraniol-DH isoenzymes were similar in molecular mass, optimal temperature, and pH, but the isoelectric point, substrate specificity, and kinetic parameters were different. The K(m) values for geraniol of geraniol-DH I and II appeared to be 0.4 mM and 0.185 mM respectively. P. minus geraniol-DHs are unusual among geraniol-DHs in view of their thermal stability and optimal temperatures, and also their high specificity for allylic alcohols and NADP(+).     

Geranylated 4-Phenylcoumarins Exhibit Anticancer Effects against Human Prostate Cancer Cells through Caspase-Independent Mechanism

Geranylated 4-phenylcoumarins, DMDP-1 & -2 isolated from Mesua elegans were investigated for anticancer potential against human prostate cancer cells. Treatment with DMDP-1 & -2 resulted in cell death in a time and dose dependent manner in an MTT assay on all cancer cell lines tested with the exception of lung adenocarcinoma cells. DMDP-1 showed highest cytotoxic efficacy in PC-3 cells while DMDP-2 was most potent in DU 145 cells. Flow cytometry indicated that both coumarins were successful to induce programmed cell death after 24 h treatment. Elucidation on the mode-of-action via protein arrays and western blotting demonstrated death induced without any significant expressions of caspases, Bcl-2 family proteins and cleaved PARP, thus suggesting the involvement of caspase-independent pathways. In identifying autophagy, analysis of GFP-LC3 showed increased punctate in PC-3 cells pre-treated with CQ and treated with DMDP-1. In these cells decreased expression of autophagosome protein, p62 and cathepsin B further confirmed autophagy. In contrary, the DU 145 cells pre-treated with CQ and treated with DMDP-2 has reduced GFP-LC3 punctate although the number of cells with obvious GFP-LC3 puncta was significantly increased in the inhibitor-treated cells. The increase level of p62 suggested leakage of cathepsin B into the cytosol to trigger potential downstream death mediators. This correlated with increased expression of cathepsin B and reduced expression after treatment with its inhibitor, CA074. Also auto-degradation of calpain-2 upon treatment with DMDP-1 &-2 and its inhibitor alone, calpeptin compared with the combination treatment, further confirmed involvement of calpain-2 in PC-3 and DU 145 cells. Treatment with DMDP-1 & -2 also showed up-regulation of total and phosphorylated p53 levels in a time dependent manner. Hence, DMDP-1 & -2 showed ability to activate multiple death pathways involving autophagy, lysosomal and endoplasmic reticulum death proteins which could potentially be manipulated to develop anti-cancer therapy in apoptosis resistant cells.     

Erythrocarpines A-E, new cytotoxic limonoids from Chisocheton erythrocarpus

Five new cytotoxic limonoids, erythrocarpines A-E (1-5), were isolated from the bark of Chisocheton erythrocarpus Hiern. Chemical structures, stereochemistry, and conformation were fully elucidated and characterized by 2D NMR, MS, and computational methods.     

The leaf development process and its significance for reducing self-shading of a tropical pioneer tree species

On a monoaxial erect stem of trees with continuous leafing, the older leaves would be quickly shaded by newer (upper) leaves if the trees did not have any compensating mechanisms to avoid self-shading. We hypothesized that the dynamic adjustment of leaf deployment, by regulating the patterns of leaf growth and by changing leaf orientation as leaves age, is a compensating mechanism. To verify this hypothesis, we analyzed leaf development and crown structure of a Far Eastern tropical pioneer tree species, Macaranga gigantea (Rub. f. et Toll.) M.A., which unfolds huge leaves directly on a monoaxial stem with a short leafing interval. Petioles required more than 90 days for full elongation and the petiole angle (the angle between the petiole axis and the vertical) increased over time. Thus, a series of leaves on a stem progressively increased in petiole length and petiole angle from the youngest to the oldest leaves. This is beneficial because it decreases the degree of self-shading within a crown. A simulation suggested that an average crown for the M. gigantea seedlings, which was constructed using empirically determined morphometric data cannot entirely eliminate self-shading within the crown. But an average crown had a lower degree of self-shading, with less dry mass allocation to the petiole than simulated crowns that were identical to the average crown in all but one respect: they had constant petiole lengths or petiole angles. We conclude that M. gigantea seedlings reduce self-shading by regulating elongation of the petiole and changes in the petiole angle with increasing leaf age.     

Genetic Relatedness among Lansium domesticum Accessions Using RAPD Markers

Genetic relatedness among 85 Lansium domesticum Corr. accessionsfrom Peninsular Malaysia were investigated using random amplifiedpolymorphic DNA (RAPD) markers. Ten primers were used for amplificationand yielded a total of 113 bands, of which 107 were polymorphic.Homology tests showed that the RAPD bands used in the studysatisfy assumptions of homology and non-allelic behaviour. Adendrogram showing genetic similarities among accessions wasconstructed based on the 107 polymorphic bands using UPGMA clusteranalysis. Jaccard similarity coefficients ranged from 0.25 to1.00 among accessions indicating a diverse genepool in the speciesindicative of different species parentage. The dendrogram separatedthe 85 accessions into three main clusters, one comprising 56accessions which possess thin-skinned fruit (mostly Dokong andLangsat), while the second has 28 accessions (mostly Duku-langsat,Duku Terengganu and Duku Johor) with thick fruit skin and thethird comprising only one accession, namely Duku hutan. Thus,RAPD analysis was a useful tool for determining the geneticrelatedness among accessions and identifying different typesof L. domesticum. Copyright 2000 Annals of Botany Company Lansium domesticum, genetic relatedness, RAPD markers, cluster analysis