3 1 Understanding the ecological and evolutionary genomics of microbial communities in palm wine fermentation Objective Palm is believed the oldest domesticated plant over the history of human and has been utilized for versatile products. It has been recognised for traditions and cultures in tropical and subtropical countries. However, it is lack of fundamental scientific information for further development. § To understand the fermentation nature, covering the influence of seasonal sap tapping, fermentation time, and palm species through microbial ecology, metabolomic, and genomic perspectives Key findings & future directions We found a swift fermentation process through the depletion of sugar within a few days, indicating a short shelf life of palm wine. Mixed acidic fermentation accompanied by the growth of lactic acid and acetic acid bacteria occurred at the same time as ethanol production, driven by a co-working of Saccharomyces cerevisiae and Zymomonas mobilis. S. cerevisiae was more assertive to the change of micro-ecological factors in the fermentation process. Seasonal sap tapping unchanged the core microbial species and metabolite composition, but they may contribute to specialize product signature. Profile of volatile esters, such as Octanoic acid, and Decanoic acid have set a baseline on determining the fermentation stage characters, capturing every palm species. We are impressed on the dominance of S. cerevisiae and Z. mobilis due to their ability on producing ethanol simultaneously. Further research has been planned to cover some questions on their genome properties affected by local geographic adaptation and their fermentation ability for best practice in the future. Significance By understanding the nature of palm wine fermentation, we can elaborate a better perspective to manage microflora for aroma and flavour, to achieve intended quality and product stability, to establish further product development, and more importantly to appreciate this traditional beverage. I Nyoman Sumerta1,2 and Kate Howell1 1 School of Agriculture, Food Ecosystem Sciences, The University of Melbourne, VIC 3010, Australia 2 National Research and Innovation Agency (BRIN), Jakarta, Indonesia GENERAL OVERVIEW ABSTRACT The important of fermentation nature of palm wine related to current results Take home messages: References: 2 4 5 Grape wine fruits based wine Rice wine grains based wine Palm wine sap based wine Palm wine is made of naturally fermented palm sap, which is significantly influenced by ecological factors and genomic characteristics of its microbial communities. Palm wine is a traditional alcoholic beverage, typically known in Africa, south Asia, southeast Asia, and central America where various palm species grow in their coastal area Ecological factors affected the microbial communities, but not in core structure Metabolite and microbial relationship MAIN RESULTS • Sumerta, IN., Ruan, X. & Howell, K. (2024) The forgotten wine: understanding the fermentation and composition of palm wine. Preprint at Biorxiv. https://doi.org/10.1101/2024.04.26.591403. • Wijaya, L., Sumerta IN., et al. (2024).Cultural, nutritional and microbial perspectives of tuak, a traditional Balinese beverage. J. Ethn. Foods 11, 4 https://doi.org/10.1186/s42779-024-00221-x o The ecological exposure likely had less impact to the core species, while VOCs were likely more affected by ecological factors o Seasonal sap tapping was the main ecological factor, that changed microbial diversity and the amount of VOCs o The role of S. cerevisiae and Z. mobilis needs further study on how they effectively work in palm wine fermentation The relative abundant of bacteria (upper row) was dominated by Zymomonas mobilis, which is known as sucrose fermenting bacteria (ethanol producing bacteria). Acetic acid bacteria (Acetobacter) showed an increase trend over the fermentation period and lactic acid bacteria was responsible for acidic fermentation. On the other hand, Sacchar