Title

Effects of linoleic acid and its degradation by-products on mesophilic hydrogen production using flocculated and granular mixed anaerobic cultures

Document Type

Article

Publication Date

2012

Publication Title

International Journal of Hydrogen Energy

Volume

37

Issue

24

First Page

18747

Last Page

18760

DOI

10.1016/j.ijhydene.2012.09.065

Keywords

Anaerobic mixed culture; Biohydrogen; biohydrogen production; chain fatty-acids; diversity; enrichment; eubacterium-limosum; fermentation; Flux balance analysis; inhibition; Linoleic acid (LA (C18:2)); Methanogenesis; myristic acid; ph; Principal component analysis (PCA); t-rflp

Abstract

The effects of linoleic acid (LA (C18:2)) and its degradation by-products on hydrogen (H-2) production were examined at 37 degrees C and an initial pH value of 5.0 using granular and flocculated mixed anaerobic cultures from the same source. In the flocculated cultures, the H-2 consumers were inhibited to a greater extent when compared to the granular cultures. The maximum H-2 yields were 2.52 +/- 0.2 and 1.9 +/- 0.2 mol mol(-1) glucose in the flocculated and granular cultures, respectively. The major long chain fatty acids (LCFAs) detected at which H-2 attained a maximum value were LA (750 mg L-1) and myristic acid (MA) (500 mg L-1). Bacteroides sp. dominated the granular cultures whereas Clostridium sp. and Bacillus spp. were the major microorganisms in the flocculated cultures. A flux balance analysis (FBA) revealed that homoacetogens consumed more H-2 in the granular when compared to the flocculated culture. A principal component analyses (PCA) showed the first three principal components accounted for approximately 76% and 68.5% of the total variability for the LA and its degradation by-products and the T-RFLP data sets, respectively. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Comments

This is an accepted manuscript version of an aritcle whose version of record was published in:International Journal of Hydrogen Energy: http://dx.doi.org/10.1016/j.ijhydene.2012.09.065