Metagenomics analysis of cocoa bean fermentation microbiome identifying species diversity and putative functional capabilities.

Fermentation of Theobroma cacao L. beans is the most critical stage in the production of cocoa products such as chocolates and its derivatives. There is a limited understanding of the complex response of microbial diversity during cocoa bean fermentation. The aim of the present study was to investigate microbial communities in the cocoa bean fermentation heap using a culture-independent approach to elucidate microbial diversity, structure, functional annotation and mapping unto metabolic pathways. Genomic DNA was extracted and purified from a sample of cocoa beans fermentation heap and was followed by library preparations. Sequence data was generated on Illumina Hiseq 2000 paired-end technology (Macrogen Inc). Taxonomic analysis based on genes predicted from the metagenome identified a high percentage of Bacteria (90.0%), Yeast (9%), and bacteriophages (1%) from the cocoa microbiome. Lactobacillus (20%), Gluconacetobacter (9%), Acetobacter (7%) and Gluconobacter (6%) dominated this study. The mean species diversity, measured by Shannon alpha-diversity index, was estimated at 142.81. Assignment of metagenomic sequences to SEED database categories at 97% sequence similarity identified a genetic profile characteristic of heterotrophic lactic acid fermentation of carbohydrates and aromatic amino acids. Metabolism of aromatic compounds, amino acids and their derivatives and carbohydrates occupied 0.6%, 8% and 13% respectively. Overall, these results provide insights into the cocoa microbiome, identifying fermentation processes carried out broadly by complex microbial communities and metabolic pathways encoding aromatic compounds such as phenylacetaldehyde, butanediol, acetoin, and theobromine that are required for flavour and aroma production. The results obtained will help develop targeted inoculations to produce desired chocolate flavour or targeted metabolic pathways for the selection of microbes for good aroma and flavour compounds formation.

Antimicrobial and Antibiofilm Activities of Helical Antimicrobial Peptide Sequences Incorporating Metal-Binding Motifs.

Antimicrobial peptides (AMPs) represent alternative strategies to combat the global health problem of antibiotic resistance. However, naturally occurring AMPs are generally not sufficiently active for use as antibiotics. Optimized synthetic versions incorporating additional design principles are needed. Here, we engineered amino-terminal Cu(II) and Ni(II) (ATCUN) binding motifs, which can enhance biological function, into the native sequence of two AMPs, CM15 and citropin1.1. The incorporation of metal-binding motifs modulated the antimicrobial activity of synthetic peptides against a panel of carbapenem-resistant enterococci (CRE) bacteria, including carbapenem-resistant Klebsiella pneumoniae (KpC+) and Escherichia coli (KpC+). Activity modulation depended on the type of ATCUN variant utilized. Membrane permeability assays revealed that the in silico selected lead template, CM15, and its ATCUN analogs increased bacterial cell death. Mass spectrometry, circular dichroism, and molecular dynamics simulations indicated that coordinating ATCUN derivatives with Cu(II) ions did not increase the helical tendencies of the AMPs. CM15 ATCUN variants, when combined with Meropenem, streptomycin, or chloramphenicol, showed synergistic effects against E. coli (KpC+ 1812446) biofilms. Motif addition also reduced the hemolytic activity of the wild-type AMP and improved the survival rate of mice in a systemic infection model. The dependence of these bioactivities on the particular amino acids of the ATCUN motif highlights the possible use of size, charge, and hydrophobicity to fine-tune AMP biological function. Our data indicate that incorporating metal-binding motifs into peptide sequences leads to synthetic variants with modified biological properties. These principles may be applied to augment the activities of other peptide sequences.

Designing metallodrugs with nuclease and protease activity.

The accidental discovery of cisplatin some 50 years ago generated renewed interest in metallopharmaceuticals. Beyond cisplatin, many useful metallodrugs have been synthesized for the diagnosis and treatment of various diseases, but toxicity concerns, and the propensity to induce chemoresistance and secondary cancers make it imperative to search for novel metallodrugs that address these limitations. The Amino Terminal Cu(ii) and Ni(ii) (ATCUN) binding motif has emerged as a suitable template to design catalytic metallodrugs with nuclease and protease activities. Unlike their classical counterparts, ATCUN-based metallodrugs exhibit low toxicity, employ novel mechanisms to irreversibly inactivate disease-associated genes or proteins providing in principle, a channel to circumvent the rapid emergence of chemoresistance. The ATCUN motif thus presents novel strategies for the treatment of many diseases including cancers, HIV and infections caused by drug-resistant bacteria at the genetic level. This review discusses their design, mechanisms of action and potential for further development to expand their scope of application.

Geographical Distribution of Cacao swollen shoot virus Molecular Variability in Ghana.

Cacao (Theobroma cacao L.) was introduced into West Africa from South America during the nineteenth century. However, cacao swollen shoot disease (CSSD) was first observed in Ghana in 1936 and, later, discovered in Nigeria, Côte d'Ivoire, Togo, and Sierra Leone. The objectives of this work were to assess the genetic diversity and spatial distribution of the Cacao swollen shoot virus (CSSV) in Ghana and investigate the origin and spread of the virus by identifying alternative host plants. Results obtained from polymerase chain reaction amplifications and phylogenetic relationship analyses of infected cacao and alternative host plants collected from the cacao-growing regions in Ghana revealed the existence of nine CSSV groups, A, B, C, E, G, J, K, L and M, with six groups detected for the first time in Ghana. The CSSV groups in Ghana are very divergent and correspond to at least five different putative species, according to the International Committee on Taxonomy of Viruses recommendations (A, B-C complex, G, E, and M), with the M species only being detected in the alternate host Ceiba pentandra. The spatial distribution of the different molecular groups in Togo, Côte d'Ivoire, and Ghana makes it difficult to predict a single origin for CSSV among the West African cacao-growing countries.

Trema orientalis Linn. Blume: A potential for prospecting for drugs for various uses.

Medicinal plants are used by traditional practitioners to treat several ailments. Ethnomedicinal studies on Trema orientalis Linn. Blume (Ulmaceae) have shown that it is used in the treatment of diabetes mellitus, respiratory diseases, oliguria, and malaria. This article is aimed at providing comprehensive information on the medicinal uses, biology, phytochemical constituents, and pharmacological data available on T. orientalis. This has been done to explore its therapeutic potential for future research opportunities. This review was compiled with information obtained from databases such as Medline, Elsevier, Springer, Science Direct, Pubmed, Google Scholar, and a library search for articles published in peer-reviewed journals. Compounds present in the plant include tannins, saponins, flavanoids, triterpenes, phytosterols, and several constituents of xanthones. Some pharmacological research done on the plant has focused on, hypoglycemic activity, analgesic, anti-inflammatory activities, anti-plasmodial activity, diuretic activity, laxativity effect, anti-convulsant activity, anti-helmintic activity, anti-sickling effect, anti-oxidant, and anti-bacterial activity. This compilation strongly supports the view that T. orientalis has beneficial therapeutic properties, and indicates its potential as an effective herbal remedy for several diseases. The promising results from several research works could be further substantiated by clinical trials.