Abstract：Abstract Litchi (Litchi chinensis Sonn.) is one of the most commercially important fruit in subtropical areas with good flavor and rich nutrients. However, pericarp browning and fruit decay during storage period with high temperature and high humidity had led to great economic loss. In order to reduce the abuse of artificial chemical fungicide, development of a new method for preservation of harvested litchi fruit had shown great importance. In this study, the fermentation broth of microbial community using Enteromorpha prolifera as subtract was used for postharvest treatment of litchi fruit. The effect of different concentrations of supernatant on visual quality and storability of harvested litchi fruit were investigated. The high-throughput sequencing technique of 16S rRNA V4 zone was used for analysis of structure and abundance of microbiota. Nuclear magnetic resonance (NMR) metabonomics technology was used for the determination of metabolites with fresh-keeping potential. Based on the sequencing of Hiseq2500 PE250 platform, the result indicated that Bacillaceae, Cyclobacteriaceae and Alteromonadaceae were main families in this microbial community, in which the Bacillus was the dominate genus with the the abundance of 32.31%. Furthermore, the abundance of Alteromonadaceae and Microbulbifer which could degrade the E. prolifera was 8.47% and 6.72%, respectively. The main preservation related substances in fermentation broth was determined as glycine betaine and trehalose, and the concentration was 0.001 5 and 0.007 9 mmol/L, respectively. Compared with the control group, the litchi fruit being dipped in the fermentation broth at different concentrations for 10 min could significantly maintain lower respiration rate of fruit, browning index, disease index and percentage of weight loss, so these after-treatment litchi fruit kept higher percentage of commercially acceptable fruit during ambient storage condition. This study provides a theoretical basis and technical method for postharvest bio-preservation of litchi fruit and other subtropical fruit.
