Assessment of the diversity and abundance of bacterial population and its correlation with medium chain fatty acids production from fermentation of two leachate qualities

Production of medium chain fatty acids from ensiled potato peels; effect of inoculum type and kinetic study

“…The fermentation profile of fatty acids production in the presence of the three inocula is shown in Figure 2. Acetic acid was the dominant fatty acid in the systems as has also been reported by other authors (Saadoun et al, 2022;Zhang et al, 2022), irrespective of the type of inoculum used. The high concentration of acetic acid during anaerobic fermentation has been attributed to the excessive oxidation of ethanol (Wu et al, 2021).…”

Converting food waste into high-value medium chain fatty acids and long chain alcohols via chain elongation with an internally produced electron donor

“…Clostridium , a well-studied model chain elongator, became the dominant bacteria involved in MCFAs production, especially in the 4Y system. 8 Specifically, the highest Clostridium abundance (5.23%) was observed in the 4Y reactor, which was approximately 4.88 times higher than that in the control and 1.69 times higher than that in the 1Y system. Therefore, the enrichment of such native organisms ensured the successful establishment of the CE process.…”

“…For instance, only 49.5 mg COD per L C 7 and 18.46 mg COD per L C 8 acids were observed in the 4Y system, despite it being thermodynamically and kinetically feasible to elongate C 5 or C 6 acids (Tables S3 and S4 †). The limited ability of organisms to elongate carboxylates to 7 or 8 carbon atoms might be one of the possible reasons for the low C 7 and C 8 acid yields in these experimental groups, 8,35 as the microbial structures in the yeast-inoculated systems were different. Besides that, the caproate contained in these systems may undergo substrate oxidation to acetate, 36 making the fromation of heptanoate and caprylate more challenging in these three yeast-inoculated systems.…”

“…The enriched genus Clostridium might be the metabolically active genera to carry out butanol synthesis, which has been validated in many coculture or pure-culture systems. 8,51,52 Potential Clostridium species with the ability to produce butanol are presented in Fig. S3.…”

“…6 However, these end products only carry low monetary value and limited application scope. 7,8 In an attempt to optimise the carbon recovery from FW while improving the economic gain during anaerobic fermentation, medium chain fatty acids (MCFAs) and long chain alcohols (LCAs) have attracted particular attention lately. 6 Medium chain fatty acids (MCFAs) are carboxylates with an aliphatic straight carbon chain consisting of 6 to 12 carbons.…”