FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

ALICJA KOŚMIDER, AGNIESZKA DROŻDŻYŃSKA, KATARZYNA CZACZYK

Title

Possibilities of wastes utilization in the propionic acid fermentation process

Abstract

The constant growth of the bio-diesel production potential in Poland, estimated to be ca. 1 MM tones in 2010, will result in the accumulation of ca. 300,000 tonnes of waste glicerol (as waste product) per year; when selling it, the price of bio-diesel will be impacted. A solution to this problem could be to apply a crude or partially refined glicerol as a component of the medium for micro-organisms producing commercially useful metabolites. In this paper, the potential was studied of utilizing pure glycerol, crude glycerol, and whey (a dairy industry waste) as a source of carbon in the biosynthesis process of propionic acid run by Propionibacterium freudenreichii ssp. shermanii. Furthermore, the efficiency of the process with a culture on standard medium was compared with the process with a propionic bacteria culture. Based on the analysis performed, it was found that the highest concentration of propionic acid (13.7 g/l) was obtained when a medium with pure glycerol as a source of carbon was applied. With other carbon sources applied: crude glycerol, whey, and their combination, the propionic acid production level was similar to the results obtained using a conventional source of carbon, i.e. glucose, and amounted to 10.5 g/l on average. It was also found that with the waste sources used, the fermentation time was extended. Under those conditions, a change in the profile of organic acids being synthesised was reported, too.

Keywords

glycerol, crude glycerol, whey, propionic acid fermentation

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