Alternative medium from agricultural by-products used for a starter of vinegar fermentation

Abstract

The objective of this research was to find a cheap agricultural waste media for the preparation of the effective starter culture of acetic acid bacteria (AAB). The alternative culture medium for AAB was compared to potato medium, preparing from pineapple peel extract (PPE) and banana juice. These media was adjusted the reducing sugar to 25 gL-1 and initial pH of 5.0 used for growing Acetobacter pasteurianus FPB2-3. The results found that this strain grew well in PPE medium comparable to potato medium and viable cells achieved the level of at least 9 log CFUmL-1 when cultured for 36 hr. While addition of banana juice, led cell growth decreased. The highest alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities in cell free extract were gained by using potato medium while the alternative media showed decrease of activity. However, these pre-culture gave acetic acid production same as the control medium, which cell completely oxidize ethanol to acetic acid. Consistently, analysis by FT-IR indicated insignificantly difference on cell components among these media. The result shows that constitutes of such agricultural by-product can be utilized as an alternative cheap inoculation media for AAB.