Research On Reducing Ethyl Lactate Content In Niulanshan Base Liquor By Microorganisms And Its Application

Ethyl lactate is one of the three esters of liquor, it’s not volatile, different hydroxyl and carboxyl motoyoshi with various types of organic components are the affinity, which react buffer balancing role with the liquor aftertaste. But the content is too high, then it will lead to the liquor astringent, rough sense, in order to reduce the content of ethyl lactate in the liquor, more uses highly alcohol degree pick the wine, which will reduce the rate of spirits yield. the use of selective medium to isolate lactate-utilizing bacteria and which use lactic acid in the fermented grains to achieve the purpose that reducing ethyl lactate.First, isolation of the index bacteria, Lu-Ye and Minimal medium were isolation and purified of the liquor micro-organisms, which two media are the sole carbon source by the lactic acid, a total of24strains were isolated from fermented grains, daqu, pit mud, yellow fermentation liquor etc the total7samples, which fermented grains have5bacteria and daqu have19index bacteria, pit mud and yellow fermentation liquor can’t be isolated bacteria.Strains that was isolated liquid fermentation, and remove the unchanged turbidity or produce biofilm fermentation broth, calculate the utilization of lactic acid, discard the samples that utilization in less than50%, and obtain13index bacteria, Lu-Ye medium have4bacteria, Minimal medium have9bacteria.Test the characteristics of the remaining13bacteria after be isolated, under the influence factors of liquor fermentation, and test performance of the strains from the mixed carbon source fermentation, anaerobic fermentation and add the alcohol fermentation. Summarize the performance of all stains, utilization of the lactic acid that isolated four effective strains in the Lu-Ye medium were lower than the nine strains that isolated in the Minimal medium after fermentation in these three conditions.Selected strains and do small scale experiments that simulate Fen-flavour liquor production process, the second batch of small scale test is reproduce the experiment for the first. Summarize experimental results of two batchs test, M5; M6have certain effects, which M6have the effect in two batchs of a small test, while M5does not reduce the ethyl lactate in the second batch of low alcohol degree segment.M5, M6were identified by agarose gel electrophoresis, initially identified M5is Bacillus tequilensis strain, M6is Bacillus amyloliquefaciens strain.Finally, M5, M6were made of bran koji, and applied to large-xcale production. In the base liquor, Ethyl lactate content have declined slightly in the M5,M6and two mixed bacteria etc three samples.