Abstract: In order to investigate the effect of microorganisms present in rice milk on the production and quality of yellow rice wine, Illumina high-throughput sequencing technology was used to comprehensively analyze the bacterial community structure in rice milk for yellow rice wine. The results showed that Lactobacillus was the dominant bacterial genus in rice milk, and its abundance was 60.67%, with Lactobacillus plantarum and Lactobacillus brevis being the most predominant, accounting for 57.4% and 21.1% of the total Lactobacillus isolates, respectively. Seven bacterial species, such as Lactobacillus plantarum and Lactobacillus brevis, were selected from a bacterial library for yellow rice wine, and then ion chromatography and gas chromatography-mass spectrometry (GC-MS) were used to determine acidic substances in their fermentation broth. It was found that Lactobacillus plantarum L4 had the strongest acid-producing capacity (9.96 g/L), and the main products were organic acids with light and fresh taste, such as lactic acid, malic acid, and citric acid. In addition, it also produced low contents of strong acid (acetic acid) and acid with bad odor (butyric acid, isovaleric acid and heptanoic acid). In the L-4 fermentation broth, the ratio of non-volatile acid to volatile acid was as high as 11.89, and the taste and odor were obviously superior to those of other strains.

Key words: Chinese rice wine, rice milk, bacterial community structure, organic acid, volatile acid