RESULTS: The pH, sugar and reducing sugars levels, organic acids content, total bacterial count (TBC) and sensory characteristics of the sample were determined. The results showed that the treated samples were able to slow down the pH and sucrose content from dropping during storage. Sample A had lactic acid at 0.93 ± 0.01 g/L and acetic acid at 0.05 ± 0.0.1 g/L, while Sample B had 0.97 ± 0.02 g/L and 0.07 ± 0.01 g/L, respectively, both lower than the control (1.10 ± 0.01 g/L and 0.09 ± 0.02 g/L). Sample A with TBC of 1.03 (± 0.08) x 105 CFU/mL was able to inhibit microbial growth better than Sample B, 1.14 (± 0.13) x 105 CFU/mL. Preservative application prior to tapping was shown to be more successful in preserving the quality and shelf-life of nipa palm sap. This approach is likely preventing early microbial activity and fermentation without the need of proper packaging, preserving the freshness and quality of the sap more effectively than adding the preservative after collection.
IMPORTANCE: Sulfate-reducing bacteria (SRB) play essential roles in global sulfur and carbon cycling and are critical for bioremediation and anaerobic digestion processes. However, detailed studies on the genotypic and phenotypic responses of SRB under varying pH conditions are limited. This study addresses this gap by examining the pH-dependent genetic and metabolic adaptations of Oleidesulfovibrio alaskensis G20, revealing key mechanisms regulating hydrogenase and ATPase activities, cell division, and extracellular polymeric substance formation. These findings provide new insights into how SRB maintains pH homeostasis, showcasing their ability to survive and function in both acidic and alkaline environments. Furthermore, this study reveals critical genetic and phenotypic characteristics that will directly aid to engineer industrial effluent management systems, bioremediation, and dissolved heavy metal recovery. By elucidating the dynamic response of O. alaskensis G20 to varied pH environments, the research provides a foundation for enhancing the resilience and performance of SRB-based systems, paving the way for improved environmental and industrial applications.