Microbiota and Metabolite Profiles in Spontaneous Pre-Fermented Coconut Water: A Driver for Nata de coco Production by Komagataeibacter nataicola
Pre-fermented coconut water harbors a diverse array of nutrients species, rendering it an exceptional resource for the synthesis of bacterial cellulose (BC). However, the natural fermentation of coconut water is subject to numerous uncontrollable factors, which consequently affect both production yield and quality in manufacturing facilities. A total of 40 pre-fermented coconut water samples were collected from the factory over a period of five months in this study. Three strains of K. nataicola, renowned for their exceptional BC synthesis ability as determined in laboratory experiments, were individually inoculated into the 40 pre-fermented coconut waters. We have observed pronounced disparities in BC production levels among these three strains. By employing microbial metabolomics, a comparative analysis was conducted on samples obtained from 40 different fermentation durations, revealing significant variations in the diversity and abundance of bacteria and fungi within pre-fermented coconut water across different months. In April, July, June, March, and May, pre-fermented coconut water exhibited the presence of 15, 8, 8, 11, and 10 distinct bacterial genera respectively. Additionally, there were observed occurrences of 10, 3, 7 ,7 and 5 diverse fungal genera. The genera Lactococcus, Liquorilactobacillus, Paucilactobacillus, erozyma exhibited higher abundance in March with LDA scores >4. In April, the significantly enriched biomarkers included unclassified Enterobacteriaceae, Acinetobacter, Enterobacter, Ogataea. May was characterized by a higher abundance of Tolumonas and Cyberlindnera Xenoacremonium. Limosilactobacillus, Klebsiella were identified as the main biomarkers in June. The biomarkers for July comprised Lactacillusococcus and Candida. Metabolite analysis reveals significant monthly variations in the metabolites present in pre-fermented coconut water, with lactic acid, mannitol, ethanol, and ascorbic acid identified as potential discriminative metabolites. Investigating the correlation between pH levels and key metabolites that influence on the structure of microbial communities. Through RDA analysis, a more in was conducted on the key metabolites that impact pH and microbial community structure. The results revealed that bacterial colonies are significantly influenced by pH, mannitol, and lactic acid, while ascorbic acid and mannitol play important roles in shaping fungal structure. The correlation network reveals a significant association between BC production and the microbial community, as well as in pre-fermented coconut water. This study offers recommendations for the industrial-scale fermentation of pre-fermented coconut water and establishes a basis for developing a microbial consortium with enhanced BC production.