Antibacterial, Anti-Inflammatory and Antioxidant Activities of an ACAZY Herbal Formula Used in Traditional Medicine to Treat Respiratory Infections

ACAZY is a plant formula used in traditional medicine in Burkina Faso to treat respiratory infections. After phytochemical analysis, this study evaluated extracts’ anti-inflammatory, antioxidant and antibacterial properties from the ACAZY recipe. Three extractions, an aqueous macerate (AM), an aqueous decoction (AD) and an hydroethanolic macerate (HEM) of the ACAZY recipe powder were carried out. Phytochemical screening of the extracts was carried out using high-performance thin-layer chromatography (HPTLC) and the determination of phenolic compounds. The anti-inflammatory potential was assessed in vitro using pro-inflammatory enzyme inhibition tests. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and Ferric-reducing antioxidant power (FRAP) antioxidant properties were also determined. The antibacterial activity was evaluated on Staphylococcus aureus and Streptococcus pneumoniae strains. Phytochemical analysis revealed the presence of flavonoids, saponins, tannins, anthracenosids, sterols and triterpenes in the extracts. The extracts inhibited pro-inflammatory enzymes by more than 40% at only 100 µg/mL. The extracts also showed potent antibacterial activity with a minimum inhibitory concentration 1 mg/mL on Staphylococcus aureus and 2 mg/mL on Streptococcus pneumoniae. The extracts in the ACAZY formula have shown anti-inflammatory and antioxidant properties in vitro. The AD also showed an antibacterial activity. This justifies its use in traditional medicine to treat acute respiratory infections.

Response Surface Methodology as an Approach for Optimization of Vinegar Fermentation Conditions Using Three Different Thermotolerant Acetic Acid Bacteria

This study aimed to investigate optimal fermentation conditions of biological acetic acid fermentation for vinegar production. Optimization was performed on 3 acetic acid bacteria strains namely VMA1, VMA7 and VMAO using Response Surface Methodology (RSM). A Box-Behnken-Design (BBD) was achieved with three different independent process parameters involving: fermentation temperature, original alcohol concentration and original acetic acid concentration and one dependent variable (acetic acid yield). The results showed that the mathematical models describe correctly the relationship between responses and factors (F values of the models (p R2 (coefficient of correlation) respectively 0.96, 0.94, 0.98, and adjusted R2 0.95, 0.92, 0.98). The maximum acidity was obtained respectively at fermentation temperatures, original alcohol concentrations and original acetic acid concentrations ranging from [37.5°C - 45°C], [16% - 20% (v/v)], [1.5% - 2% (w/v)] for VMA1, [40°C - 45°C], [14.5% - 20% (v/v)], [1.7% - 2% (w/v)] for VMA7 and [42°C - 45°C], [17% - 20% (v/v)], [1.5% - 2% (w/v)] for VMAO. The use of these acetic strains in the production of vinegar may seriously lead to a decrease or even an ablation of the costs related to the cooling of bioreactors especially in warm and hot countries, in the context of global warming.

Isolation and Characterization of Native Rhizobium Strains Nodulating Some Legumes Species in South Brazzaville in Republic of Congo

Actually, in Republic of Congo, rhizobia have poorly phenotypically and biochemically characterized. This study aimed to characterize native rhizobia. Rhizobia strains were isolated using nodule roots collected on Milletia laurentii, Acacia spp., Albizia lebbeck, and Vigna unguiculata. The strains isolated were characterized microbiologically, biochemically, physiologically, and molecularly identified using 16S rRNA method. The results reported in this study are only for six strains of all 77 isolated: RhA1, RhAc4, RhAc15, RhAc13, RhW1, and RhV3. All native strains were positive to urease activity, negative to cellulase and pectinase activity except for one isolate that showed a positive cellulase activity. Moreover, isolates have grown at 12% of NaCl. On different effects of temperatures, isolates were able to grow up to 44°C and showed good growth at pH from 7 to 9 and the ability to use ten different carbon hydrates sources. The strains were identified as Rhizobium tropici, Rhizobium sp., Mesorhizobium sp. Bradyrhizobium yuanmingense and Bradyrhizobium elkanii. The phylogenetically analysis of the 16S rRNA genes, using a clustering method, allowed us to have a history that is both ancient and stable of four clades among genes with similar patterns. Expanding our awareness of the new legume-rhizobia will be a valuable resource for incorporating an alternative nitrogen fixation approach to consolidate the growth of legumes. These germs can be used in Congolese agriculture to improve yield of crops.

Isolation and Characterization of Lactic Acid Bacteria Producing Bacteriocin like Inhibitory Substance (BLIS) from “Gappal”, a Dairy Product from Burkina Faso

Indigenous fermented foods are known for their nutritional and functional properties but they are often spoiled by pathogenic bacteria that can constitute a food safety problem. “Gappal” is a no-thermal treat food based on millet dough and milk and its production conditions can constitute a food safety problem. The aim of this study was to screen and identify LAB producing Bacteriocin-like inhibitory substances using a matrix similar to “Gappal”. The detection of potential BLIS was first performed using overlaid method after enrichment of samples in whey and millet dough. The isolates demonstrating inhibiting area were preselected, purified and tested for the presence of antibacterial properties using their neutralized cell-free culture supernatant and subsequently treated with catalase in combination with protease, pepsin or trypsin. The antimicrobial effect of two isolates (Gbf48 and Gbf50) after growth on MRS broth over 12 h at 30?C were active against E. faecalis ATCC 19433, M. luteus ATCC 49732, S. aureus ATCC 2523, L. monocytogenes, B. megaterium, B. sphaericus and B. cereus with an activity of 2560 AU/mL. The 16S RNA gene sequencing identification indicated that these isolates are Pediococcus acidilactici. Gbf 48 and Gbf 50 could be used to improve preservative factors for a controlled fermentation of non thermal treatment fermented food for their potential of acidification adds to BLIS production.