Responses of Lactiplantibacillus plantarum and Candida glabrata Isolated from Retted Cassava to Acid Stress and Their Influence on Substrate Fermentation for Gari Production

Aim: Fermentation subject microbial cells to stress, such as, acid stress which can lead to inactivation of cells and consequently death. Microbial cells have developed mechanisms of adapting to these stress conditions. In this study therefore, the physiological and proteomic responses of Lactiplantibacillus plantarumLC03 and Candida glabrataYC02 to acid stress and their influence on substrate fermentation for Gari production has been investigated. Methodology: Using the turbidimetry method and SDS-PAGE; LC-MS/MS, the physiological and proteomic responses of the LAB and yeast to acid stress were assessed. Analysis of the physiocochemical and organoleptic properties of the fermented cassava using the LAB and yeast alone and in combination was conducted by means of standard methods. Results: Lactiplantibacillus plantarumLC03 and Candida glabrataYC02 had growth at pH 1, 2 and pH 3 respectively with an increased protein intensity of Type I glyceraldehyde-3-phosphate dehydrogenase and enolase 2 respectively. The lowest cyanide content (6.49d), highest protein content (0.94c) and improved organoleptic acceptability (7.92a) was observed in Gari produced with the combination of Lactiplantibacillus plantarumLC03 and Candida glabrataYC02 as starters with significant differences in Gari produced with single starters of Lactiplantibacillus plantarumLC03 and Candida glabrataYC02 and control. Conclusion: Increased protein intensity during acid stress conditions enhanced the survival of Lactiplantibacillus plantarumLC03 and Candida glabrataYC02 (starters), thereby, improving the quality (improved sensory properties, nutritional and reduced anti-nutrient contents) of Gari produced.