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.

The study was carried out to assess genetic diversity among forty-one sorghum accessions obtained from Savanna Agricultural Research Institute (SARI), Nyankpala, Northern Region of Ghana and the germplasm collection of Department of Molecular Biology and Biotechnology, University of Cape Coast. Genetic diversity and relationship among the forty-one accessions were evaluated using 22 microsatellite primers. The 22 markers generated 92 alleles, with a mean of 4.2, indicating an average range of diversity. The average polymorphic information content (PIC) was 0.44, indicating that the microsatellites were informative. The cluster analysis grouped the 41 cultivars into seven distinct clusters. The most genetically distinct genotypes were Edipipii, Jibare and Belkozia, which did not cluster with any other line. The similarity between the sorghum accessions ranged from 77 to 100%. Observed heterozygosity ranged from 0 to 0.17 with an average of 0.03 per locus. Results of this study indicated that the landraces were related, and were probably exchanged between farmers in the collection regions, with some duplication found in the material, indicating that there must have been a common source of material somewhere in the history of the breeding programmes. Nonetheless, the Edipipii, Jibare and Belkozia could be exploited in breeding programmes to transfer desirable traits into elite Ghanaian sorghum cultivars.

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Soil contamination through oil spillage accumulates in the soil and affect plant growth. The study was conducted to examine the effect of spilled engine oil on soil nutrients and germination of seed in the in the Central region of Ghana. Ten samples were collected randomly from selected mechanic and fitting sites in the Elmina municipality. A randomized complete block design using three test crops was used to evaluate soil quality indicators such as N, P, K and soil pH on the polluted soil using standard methods. Maize recorded 3.67, 18.5 and 3.7% germination in contaminated soils from Aponkyedasoro, Nippon and Afitafum, respectively. Cowpea and sorghum recorded no germination in these soils. The three crops showed higher germination rates in the control soils, with the highest being recorded in sorghum (72.2%), followed by cowpea (70.4%) with the least being recorded in maize (66.6%). The results showed that nitrogen (N) level in the experimental soil was very low (0.065-0.075%) as compared to the control (0.115%) in this study. However, polluted soil from Aponkyedasoro, Afitafum and Nippon recorded a higher level of phosphorus (60.84-31.58 µg/g) and potassium (0.52-0.58 µg/g) than control (P=20.97 µg/g; K=0.43 µg/g) despite having a low germination rate. Copper, zinc, sodium and iron concentration were higher in the engine oil-polluted soil. The study revealed that the concentration of heavy metals and spilled engine oil in the soil has a higher effect on plant development; hence, public awareness should be created of its detrimental effect on the ecosystem.

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