In Burkina Faso, deficiency of amino acids in protein is becoming a major healthy public problem. This study was purposed to optimize essentials amino acids in single cell protein (SCP) by supplementing different nitrogen sources during fermentation of mango waste with Candida utilis FJM12. Analytical methods were used to determine biomass yield, chemical composition and amino acids profile of SCP. The principal component analysis (PCA) method was performed to identify the nitrogen source which exhibited best rate of SCP. The maximum biomass yield (6.48±0.03 g/L) exhibited 9.65±0.36% (w/w) of ash, while using yeast extract. The proximate composition of SCP revealed 56. 40±1.30, 13.25±0.11, 3.80±0.10 and 6.60±0.25% (w/w), respectively for crude protein, lipids, carbohydrates, and nucleic acid content. PCA showed a strong correlation between yeast extract and ammonium sulphate and demonstrated their positive influence to increase the rate of SCP and essentials amino acids as compared to Food and Agriculture Organization (FAO) recommendation. These results demonstrated that C. utilis FJM12 could be suitable for essentials amino acids.

Environmental pollution can have detrimental effects on crop yield and its consumers. The current study was designed to investigate the potential human health risks associated with the consumption of lettuce crop contaminated with toxic heavy metals and microbiological status. Irrigated water, soil and lettuce were analyzed by AAS technics for heavy metals including Cd, Cr, Cu, Mn, Ni, Pb and Zn. Transfer factor (TF), daily intake of metals (DIM) and health risk index (HRI) were also calculated. Microbial analysis was carried out for the presence foodborne pathogens. The results showed that the heavy metals contents were higher in the soil than wastewater and the vegetables. Heavy metals ranged (mg•Kg −1) for Cd (1.27 to 2.93), Cr (7.28 to 7.38), Cu (0.91 to 1.70), Mn (0.29 to 6.60), Ni (1.74 to 2.16), Pb (1.32 to 1.69), Zn (3.08 to 3.79); and were higher than the WHO maximum limit permissible (ML) in vegetables. HRI < 1 indicates minimal risk. TF values designated an enhanced bio-contamination. Microbial numeration revealed the presence of spoiler and pathogenic microorganisms. The lettuce tested was not safe for human use, especially for direct consumption by human beings.

Rabilé is a ferment of dolo, a traditional sorghum beer of Burkina Faso and it is harvested at the end of dolo fermentation process. It is a significant source of proteins and it is used like a condiment and food seasoning by some communities. The present study characterized and identified the yeasts isolated from Rabilé. A total of 70 samples were collected from 7 localities of Burkina Faso with dolo sellers according to the ethnic groups. The aerobic mesophilic flora count from Rabilé varied from 8.34 ± 0.72 to 10.07 ± 0.51 log 10 CFU•g −1 and yeast varied from 7.24 to 8.28 log 10 UFC•g −1. Based on morphological, cultural, sexual and biochemical (carbon and nitrogen assimilation) profiles, 50 yeast strains were identified and found to belong to 4 genera and 7 species. Saccharomyces cerevisiae was found as most predominant yeasts species of yeast in of Rabilé with 64 %, Rhodotorula muciloginosa, (8%), Candida pseudorhangii (6%), Candida heliconiae (12%), Candida utilis (4%), Shizosaccharomyces pombe (4%) and Sporobolomyces odoratus (2%).

Rabilé" is dried yeast harvested from Sorghum beer, used as a traditional starter culture but more especially as ingredient in sauce and food cooking in Burkina Faso. The present study aimed to isolate and identify indigenous yeast flora of "Rabilé". Standard microbiological process was carried out to value and isolate yeast in different samples of "Rabilé" coming from four localities of Burkina Faso. Phenotypical method and molecular method (PCR and RFLP) were used for yeast strains characterization and identification. The results showed that yeast counts ranged from 9.49 to 10.35 log cfu/g of "Rabilé". A total of twenty yeast strains were isolated. Based on phenotypical characters three genera were detected: Candida (40%), Saccharomyces (35%) and Rhodotorula (25%). Molecular identification revealed two specific strains among yeasts isolated as S. cerevisiae with a frequency of 35% and R. mucilaginosa with a frequency of 25%. This data highlights the diversity of indigenous yeast flora of "Rabilé".

Rabilé" is a popular traditional ferment in Burkina Faso, consisting mainly of yeasts. It is used as a food supplement or additive like Single Cell Protein (SCP). The present work focused on identifying yeast microbiota in local food, and studying their growth kinetic parameters. "Rabilé" sampling from the 13 regions of Burkina Faso was used to isolate yeast strains. Molecular methods, including PCR-RFLP, Sanger Sequencing, and Single Locus Analysis, were applied for strain identification. The kinetic parameters were determined in batch culture. The results show 390 isolates belonging to 12 species with a predominance of Saccharomyces cerevisiae, followed by Cutaneotrichosporon curvatus. Among the selected strains, S. cerevisiae OG22 and Kluyveromyces marxianus KY01 showed the highest maximum growth rate (0.566 and 0.568 h -1 ) concerning kinetic parameters. These results demonstrate that "Rabilé" is an important biotope of yeast strains, and could be a potential food supplement.

The present study aims at optimizing the production of Saccharomyces cerevisiae SKM10 single cell proteins (SCP) from mango waste. To optimize the production process, the effect of two independent variables was evaluated by a three-level full factorial design using response surface methodology (RSM). The parameters studied were inoculum size (2 to 12% v/v) and concentration of substrates (5 to 10 g/L). Analytical methods were used to determine yeast cell biomass, sugar and protein content in yeast. Under optimal conditions, sugar content and maximum cell dry weight attained were 15.28 and 29.85% (w/w). Optimal protein content of 79.14% (w/w) was achieved at 8% (v/v) inoculum and 8% (g/L) substrate concentration. These results have provided useful information on how to improve the production by RSM and suggested that S. cerevisiae SKM10 might be applied effectively to produce SCP using mango waste as a low-cost substrate.

Background: Quantitative PCR (qPCR) can be used to detect and quantify a load of a pathogen. It is a good indicator of the degree of transmissibility. While performing routine qPCR, we observed an unusually short cycle threshold (Ct) value of SARS-CoV-2 for a clinical specimen obtained in Bamako, Mali. This prompted us to sequence the short-cycle SARS-CoV-2 sample to identify potential mutations in the Spike gene (S gene) gene. Methods: Post-infection, Quantitative Reverse Transcription (qRT-PCR) was performed over a defined time course to estimate the Ct of the SARS-CoV-2 specimen collected from the patient. Sanger sequencing was done on the entire fragment of the S gene to identify mutations. Findings: Sanger sequencing revealed mutations in the lineage of interest, designated B.1.525 by Pango, and also known as "Eta" using the nomenclature defined by WHO. This variant was originally found in Nigeria and Italy. The four novel mutations identified in Eta (D228N, Y451N, I1172M, and C1250F) were otherwise observed with a low frequency worldwide. Although the initial Ct was 10 in the case study patient, he did not exhibit severe symptoms of SARS-CoV-2, for example, pneumonia. However, we observed a longer viral clearance period than usual, of 3 weeks. We note that as compared to SARS-CoV-2 samples obtained during the first peaks of SARS-CoV-2 infection in Mali, when the

In recent years, research on yeasts as probiotics has gained more and more interest, which will allow the development of “new” products in the probiotics market. In this context, seventeen yeast strains isolated from Rabilé, a traditional beer produced in Burkina Faso, were assessed for their probiotic attributes. The yeast identification was performed by molecular methods, including PCR-RFLP and 5.8S-ITS region sequencing. Saccharomyces cerevisiae (14 strains) was the predominantly identified species, followed by Pichia kudriavzevii (2 strains) and Rhodotorula mucilaginosa (1 strain). Except for R. mucilaginosa, all yeast strains grew well at human temperature. The yeast strains showed high resistance when they were exposed to simulated gastrointestinal conditions. Auto-aggregation ability was between 70.20 ± 10.53% and 91.82 ± 1.96%, while co-aggregation with E. coli ranged from 24.92 ± 3.96% to 80.68 ± 9.53% and with S. enterica serovar Typhimurium from 40.89 ± 8.18% to 74.06 ± 7.94%. Furthermore, the hydrophobicity of isolated strains toward n-hexane was in the range from 43.17 ± 5.07% to 70.73 ± 2.42%. All yeast strains displayed high antioxidant capabilities, and the strains did not show hemolysis halos, such that they can be considered safe. Additionally, S. cerevisiae strains strongly inhibited the growth of foodborne pathogens. This is the first preliminary study to identify and characterize the yeast strains isolated from Rabilé with interesting probiotic properties.