Côte d’Ivoire has the largest cashew tree cultivation area in the world, but the cashew apple produced is still underutilized despite its potential for industrial use. The present study aimed to isolate and identify acetic acid bacterial strains and assess their potential use for cashew apple-based vinegar production. Vinegar mother from fermented juice was used to isolate acetic acid bacteria on a standard glucose-based medium. Physiological and biochemical tests followed by 16S rRNA gene analysis and phylogeny were used for isolate characterization. Moreover, their acetic acid production capacity was assessed. As results, five strains of the Acetobacter genus were isolated. Phenotypic and phylogenetic analysis revealed that four of them, namely OYA2, OYA6, OYA9, and OYA10, belong to the A. tropicalis/A. senegalensis species complex with 99.7% or 100% similarity. The fifth strain, OYA7, being similar (99.7%) to A. syzygii. All the isolates were resistant to alcohol 15% (v/v) and grew well between pH 5.0 and 6.5. Their optimal growth temperatures varied between 27 °C and 37 °C, and only isolate OYA6 grew at a temperature of up to 40 °C. They produced vinegar with a yield (Y_p/s, g/g) varying from 0.82 to 0.92, and acetic acid contents (g/L) of 80.67, 70.26, 70.11, 68.70 and 67.22 were obtained with OYA6, OYA7, OYA2, OYA10, and OYA9, respectively. Thus, the isolate OYA6 appeared as the best candidate for vinegar production, owing to its superior yield and thermotolerance abilities that need to be further explored for industry use.

Côte d’Ivoire has the main cashew tree culture area worldwide, but the cashew apple produced is still underutilized although its potential for industry. In the present study, the aim was to isolate and identify acetic acid bacterial strains, and to assess their potential use for cashew apple-based vinegar production. Vinegar mother from fermented juice was used to isolate acetic acid bacteria on a standard glucose-based medium. Physiological and biochemical tests followed by 16S rRNA gene analysis and phylogeny were used for isolate characterization. Moreover, their acetic acid production capacity was assessed. As results, five (05) strains of the Acetobacter genus were isolated. Phenotypic and phylogenetic analysis revealed that four of them, namely OYA2, OYA6, OYA9, and OYA10, belong to A. tropicalis / A. senegalensis species complex with 99,7% or 100% similarity. The last strain, OYA7, match to A. syzygii (99,7%). All the isolates were resistant to 15° alcohol (v/v) and grew well between pH 5.0 and 6.5. Their optimal growth temperatures varied between 27°C and 37°C, and only isolate OYA6 grows up to 40°C. They produced vinegar with yield (Yp/s , g/g) varying from 0.82 to 0.92, and acetic acid content (g/L) of 80.67 ± 2.1, 70.26 ± 0.9, 70.11 ± 1.7, 68.70 ± 1.5 and 67.22 ± 0.40 were obtained with OYA6, OYA7, OYA2, OYA10, and OYA9, respectively. Thus, the isolate OYA6 appeared as the best candidate for vinegar production, owing to its superior yield and thermotolerance ability that need to be further explored for industry use purpose.

Background: Basal stem rot (BSR) affects oil palm cultivation in Côte d’Ivoire. Although the disease has been documented in southern plantations, the identities and pathogenicity of associated fungal isolates remain insufficiently characterised. Aims: To identify fungal isolates associated with BSR in southern Côte d’Ivoire and assess their pathogenicity on oil palm seedlings. Study Design: Laboratory identification and nursery pathogenicity experiments. Place of Study: Oil palm plantations in Ehania, Eloka and Boubo, with pathogenicity testing at the Robert Michaux Research Station, Dabou. Methodology: Basidiocarps were collected from symptomatic palms, and isolates were identified using internal transcribed spacer (ITS) sequencing and phylogenetic analysis. Two-month-old oil palm seedlings were inoculated by immersing their roots in mycelial suspension for 30 minutes. Disease incidence and disease severity index (DSI) were assessed for GN6, GN13 and GN19. Results: Three of 15 sampled basidiocarps exhibited typical Ganoderma characteristics. The three isolates showed 95–96% ITS sequence similarity to Ganoderma zonatum and grouped with this species in the phylogenetic analysis. Seedlings developed chlorosis and necrosis following inoculation. Overall disease incidence was 83.32% for GN6, 69.77% for GN13 and 68% for GN19. At three weeks, DSI values were 83%, 63% and 88%, respectively. GN6 had the highest overall disease incidence, whereas GN19 had the highest week-three DSI. Conclusion: The findings support an association between G. zonatum and BSR in the sampled plantations. Further sampling and pathogenicity testing are required to establish the distribution and variability of the associated isolates.