METHOD FOR PREPARING SHORT-CHAIN FATTY ACID HAVING HIGH PROPANOIC ACID CONTENT BY CONTINUOUS FERMENTATION

摘要

Disclosed is a method for preparing short-chain fatty acids having high propanoic acid content, comprising: mix sludge and kitchen wastes for pre-fermentation to produce substrates required for synthesis of propionic acid, and then add propionibacterium to conduct anaerobic continuous fermentation, content of propionic acid in the final fermentation broth is as high as 71.2% of the total acid.

主权项

1. A method for preparing short-chain fatty acids having high propanoic acid content by continuous fermentation, comprising the following steps:
(1) Mix sludge, kitchen wastes and alkali for anaerobic fermentation; (2) Discharge a certain volume of fermentation mixture from anaerobic fermentation reactor at a time interval, and then add fresh sludge, kitchen waste and alkali; (3) Centrifuge discharged mixture, take out a portion of low layer solid substance after centrifugation, add water and mix in suspension oscillator, then inject together with the fresh sludge, the kitchen waste and the alkali in step (2) into anaerobic hydrolysis fermentation tank; fetch supernatant after centrifugation to sterilize in sterilization oven, after cooling down to room temperature, adjust pH value to 6-8, and inject into anaerobic acidogenic fermentation tank; (4) Prepare seed culture solution of propionibacterium, and add into the anaerobic acidogenic fermentation tank to produce propionic acid by fermentation; (5) Discharge a part volume of fermentation broth from the anaerobic acidogenic fermentation tank at a time interval, obtain propionic acid-rich fermentation supernatant after centrifugation, meanwhile, supplement sterilized supernatant after centrifugation and the seed culture solution of propionibacterium to the anaerobic acidogenic fermentation tank.