scholarly journals Effluent solids recirculation to municipal sludge digesters enhances long-chain fatty acids degradation capacity

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Sepehr Shakeri Yekta ◽  
Tong Liu ◽  
Thuane Mendes Anacleto ◽  
Mette Axelsson Bjerg ◽  
Luka Šafarič ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Conversion Efficiency ◽  
Biogas Production ◽  
Operating Conditions ◽  
Long Chain Fatty Acids ◽  
Municipal Sludge ◽  
Substantial Impact ◽  
Effluent Recirculation ◽  
Long Chain ◽  
Chain Fatty Acids

Abstract Background Slow degradation kinetics of long-chain fatty acids (LCFA) and their accumulation in anaerobic digesters disrupt methanogenic activity and biogas production at high loads of waste lipids. In this study, we evaluated the effect of effluent solids recirculation on microbial LCFA (oleate) degradation capacity in continuous stirred-tank sludge digesters, with the overall aim of providing operating conditions for efficient co-digestion of waste lipids. Furthermore, the impacts of LCFA feeding frequency and sulfide on process performance and microbial community dynamics were investigated, as parameters that were previously shown to be influential on LCFA conversion to biogas. Results Effluent solids recirculation to municipal sludge digesters enabled biogas production of up to 78% of the theoretical potential from 1.0 g oleate l−1 day−1. In digesters without effluent recirculation, comparable conversion efficiency could only be reached at oleate loading rates up to 0.5 g l−1 day−1. Pulse feeding of oleate (supplementation of 2.0 g oleate l−1 every second day instead of 1.0 g oleate l−1 every day) did not have a substantial impact on the degree of oleate conversion to biogas in the digesters that operated with effluent recirculation, while it marginally enhanced oleate conversion to biogas in the digesters without effluent recirculation. Next-generation sequencing of 16S rRNA gene amplicons of bacteria and archaea revealed that pulse feeding resulted in prevalence of fatty acid-degrading Smithella when effluent recirculation was applied, whereas Candidatus Cloacimonas prevailed after pulse feeding of oleate in the digesters without effluent recirculation. Combined oleate pulse feeding and elevated sulfide level contributed to increased relative abundance of LCFA-degrading Syntrophomonas and enhanced conversion efficiency of oleate, but only in the digesters without effluent recirculation. Conclusions Effluent solids recirculation improves microbial LCFA degradation capacity, providing possibilities for co-digestion of larger amounts of waste lipids with municipal sludge.

Influence of mesophilic and thermophilic conditions on the anaerobic digestion of food waste: Focus on the microbial activity and removal of long chain fatty acids

2018 ◽  
Vol 36 (11) ◽  
pp. 1106-1112 ◽  
Author(s):  
Xiaohui Guo ◽  
Kang Kang ◽  
Gaoyuan Shang ◽  
Xiunan Yu ◽  
Ling Qiu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Microbial Activity ◽  
Food Waste ◽  
Biogas Production ◽  
Organic Loading Rate ◽  
Long Chain Fatty Acids ◽  
Methanogenic Activity ◽  
Long Chain ◽  
Chain Fatty Acids

The mesophilic reactor (MR) exhibited advantages in biogas production and performance stability over thermophilic reactor (TR) during the long-term anaerobic digestion (AD) of food waste (FW) with stepwise organic loading rate elevating. It was interesting to explore the mechanism causing the divergences in performances between these two reactors. The microbial activity was compared on day 110 when TR began to deteriorate. The results show that MR had significantly higher specific acetoclastic methanogenic activities (SAMA) and specific propionate and butyrate oxidative activities (SPOA and SBOA) than TR. The SAMA, SPOA and SBOA in TR were only 50.3%, 18.6% and 46.4% of those values in MR, respectively. Remarkably, the specific hydrogenotrophic methanogenic activity of 15.5±2.1, 15.7±4.6 mmol CH4·L−1 original slurry·d−1 in MR and TR was comparative with insignificant difference, which indicates that the microbial activity in TR had been inhibited widely apart from the hydrogenotrophic methanogenesis. Additionally, many particles with the diameters of 1–2 mm were observed to form in MR and identified as complexes of calcium and long chain fatty acids (LCFAs). The formation of calcium crystallization might alleviate the inhibition of LCFAs during AD of FW, which further supports the better performance in MR than TR.

scholarly journals Erratum to “Inhibitory Effect of Long-Chain Fatty Acids on Biogas Production and the Protective Effect of Membrane Bioreactor”

2016 ◽  
Vol 2016 ◽  
pp. 1-2 ◽  
Author(s):  
Kris Triwulan Dasa ◽  
Supansa Y. Westman ◽  
Ria Millati ◽  
Muhammad Nur Cahyanto ◽  
Mohammad J. Taherzadeh ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Protective Effect ◽  
Membrane Bioreactor ◽  
Biogas Production ◽  
Inhibitory Effect ◽  
Long Chain Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids

scholarly journals Inhibitory Effect of Long-Chain Fatty Acids on Biogas Production and the Protective Effect of Membrane Bioreactor

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Kris Triwulan Dasa ◽  
Supansa Y. Westman ◽  
Ria Millati ◽  
Muhammad Nur Cahyanto ◽  
Mohammad J. Taherzadeh ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Protective Effect ◽  
Membrane Bioreactor ◽  
Biogas Production ◽  
Inhibitory Effect ◽  
Lower Percentage ◽  
Long Chain Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids

Anaerobic digestion of lipid-containing wastes for biogas production is often hampered by the inhibitory effect of long-chain fatty acids (LCFAs). In this study, the inhibitory effects of LCFAs (palmitic, stearic, and oleic acid) on biogas production as well as the protective effect of a membrane bioreactor (MBR) against LCFAs were examined in thermophilic batch digesters. The results showed that palmitic and oleic acid with concentrations of 3.0 and 4.5 g/L resulted in >50% inhibition on the biogas production, while stearic acid had an even stronger inhibitory effect. The encased cells in the MBR system were able to perform better in the presence of LCFAs. This system exhibited a significantly lower percentage of inhibition than the free cell system, not reaching over 50% at any LCFA concentration tested.

scholarly journals Differential Effects of Fatty Acid Saturation and Chain Length on NASH in Juvenile Iberian Pigs

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 682-682 ◽  
Author(s):  
Kayla Dillard ◽  
Morgan Coffin ◽  
Gabriella Hernandez ◽  
Victoria Smith ◽  
Catherine Johnson ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Body Weight ◽  
Fatty Acid ◽  
Liver Injury ◽  
Olive Oil ◽  
Coconut Oil ◽  
Long Chain Fatty Acids ◽  
Medium Chain ◽  
Long Chain ◽  
Chain Fatty Acids

Abstract Objectives Non-alcoholic fatty liver disease (NAFLD) represents the major cause of pediatric chronic liver pathology in the United States. The objective of this study was to compare the relative effect of inclusion of isocaloric amounts of saturated medium-chain fatty acids (hydrogenated coconut oil), saturated long-chain fatty acids (lard) and unsaturated long-chain fatty acids (olive oil) on endpoints of NAFLD and insulin resistance. Methods Thirty-eight 15-d-old Iberian pigs were fed 1 of 4 diets containing (g/kg body weight × d) 1) control (CON; n = 8): 0 g fructose, 10.5 g fat, and 187 kcal metabolizable energy (ME), 2) lard (LAR; n = 10): 21.6 g fructose, 17.1 g fat (100% lard) and 299 kcal ME, 3) hydrogenated coconut oil (COCO; n = 10): 21.6 g fructose, 16.9 g fat (42.5% lard and 57.5% coconut oil) and 299 kcal ME, and 4) olive oil (OLV, n = 10): 21.6 g fructose, 17.1 g fat (43.5% lard and 56.5% olive oil) and 299 kcal ME, for 9 consecutive weeks. Body weight was recorded every 3 d. Serum markers of liver injury and dyslipidemia were measured on d 60 at 2 h post feeding, with all other serum measures assessed on d 70. Liver tissue was collected on d 70 for histology, triacylglyceride (TG) quantification, and metabolomics analysis. Results Tissue histology indicated the presence of steatosis in LAR, COCO and OLV compared with CON (P ≤ 0.001), with a further increase in in non-alcoholic steatohepatitis (NASH) in OLV and COCO compared with LAR (P ≤ 0.01). Alanine and aspartate aminotransferases were higher in COCO and OLV (P ≤ 0.01) than CON. All treatment groups had lower liver concentrations of methyl donor's choline and betaine versus CON, while bile acids were differentially changed (P ≤ 0.05). COCO had higher levels of TGs with less carbons (Total carbons < 52) than all other groups (P ≤ 0.05). Several long-chain acylcarnitines involved in fat oxidation were higher in OLV versus all other groups (P ≤ 0.05). Conclusions Inclusion of fats enriched in medium-chain saturated and long-chain unsaturated fatty acids in a high-fructose high-fat diet increased liver injury, compared with fats with a long-chain saturated fatty acid profile. Further research is required to investigate the mechanisms causing this difference in physiological response to these dietary fat sources. Funding Sources ARI, AcornSeekers.

Long chain fatty acids can form aggregates and affect the membrane integrity

2021 ◽  
Vol 204 ◽  
pp. 111795
Author(s):  
Gulen Melike Demirbolat ◽  
Goknil Pelin Coskun ◽  
Omer Erdogan ◽  
Ozge Cevik
Keyword(s):  
Fatty Acids ◽  
Membrane Integrity ◽  
Long Chain Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids
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