scholarly journals Identification and Cultivation of Anaerobic, Syntrophic Long-Chain Fatty Acid-Degrading Microbes from Mesophilic and Thermophilic Methanogenic Sludges

2006 ◽  
Vol 73 (4) ◽  
pp. 1332-1340 ◽  
Author(s):  
Masashi Hatamoto ◽  
Hiroyuki Imachi ◽  
Akiyoshi Ohashi ◽  
Hideki Harada
Keyword(s):  
Fatty Acid ◽  
Enrichment Culture ◽  
Stable Isotope Probing ◽  
Chain Fatty Acid ◽  
Rrna Gene ◽  
Long Chain Fatty Acid ◽  
Bacterial Populations ◽  
Enrichment Cultures ◽  
The Family ◽  
Long Chain

ABSTRACT We investigated long-chain fatty acid (LCFA)-degrading anaerobic microbes by enrichment, isolation, and RNA-based stable isotope probing (SIP). Primary enrichment cultures were made with each of four LCFA substrates (palmitate, stearate, oleate, or linoleate, as the sole energy source) at 55�C or 37�C with two sources of anaerobic granular sludge as the inoculum. After several transfers, we obtained seven stable enrichment cultures in which LCFAs were converted to methane. The bacterial populations in these cultures were then subjected to 16S rRNA gene-based cloning, in situ hybridization, and RNA-SIP. In five of seven enrichment cultures, the predominant bacteria were affiliated with the family Syntrophomonadaceae. The other two enrichment cultures contained different bacterial populations in which the majority of members belonged to the phylum Firmicutes and the class Deltaproteobacteria. After several attempts to isolate these dominant bacteria, strain MPA, belonging to the family Syntrophomonadaceae, and strain TOL, affiliated with the phylum Firmicutes, were successfully isolated. Strain MPA converts palmitate to acetate and methane in syntrophic association with Methanospirillum hungatei. Even though strain TOL assimilated [13C]palmitate in the original enrichment culture, strain TOL has not shown the ability to degrade LCFAs after isolation. These results suggest that microbes involved in the degradation of LCFAs under methanogenic conditions might not belong only to the family Syntrophomonadaceae, as most anaerobic LCFA-degrading microbes do, but may also be found in phylogenetically diverse bacterial groups.

scholarly journals Diversity of Anaerobic Microorganisms Involved in Long-Chain Fatty Acid Degradation in Methanogenic Sludges as Revealed by RNA-Based Stable Isotope Probing

2007 ◽  
Vol 73 (13) ◽  
pp. 4119-4127 ◽  
Author(s):  
Masashi Hatamoto ◽  
Hiroyuki Imachi ◽  
Yuto Yashiro ◽  
Akiyoshi Ohashi ◽  
Hideki Harada
Keyword(s):  
Fatty Acid ◽  
Stable Isotope ◽  
Major Fatty Acid ◽  
Stable Isotope Probing ◽  
Chain Fatty Acid ◽  
Long Chain Fatty Acid ◽  
Bacterial Populations ◽  
Anaerobic Microorganisms ◽  
Degrading Bacteria ◽  
Long Chain

ABSTRACT Long-chain fatty acid (LCFA) degradation is a key step in methanogenic treatment of wastes/wastewaters containing high concentrations of lipids. However, despite the importance of LCFA-degrading bacteria, their natural diversity is little explored due to the limited availability of isolate information and the lack of appropriate molecular markers. We therefore investigated these microbes by using RNA-based stable isotope probing. We incubated four methanogenic sludges (mesophilic sludges MP and MBF and thermophilic sludges TP and JET) with 13C-labeled palmitate (1 mM) as a substrate. After 8 to 19 days of incubation, we could detect 13C-labeled bacterial rRNA. A density-resolved terminal restriction fragment length polymorphism fingerprinting analysis showed distinct bacterial populations in 13C-labeled and unlabeled rRNA fractions. The bacterial populations in the 13C-labeled rRNA fractions were identified by cloning and sequencing of reverse-transcribed 16S rRNA. Diverse phylogenetic bacterial sequences were retrieved, including those of members of the family Syntrophaceae, clone cluster MST belonging to the class Deltaproteobacteria, Clostridium clusters III and IV, phylum Bacteroidetes, phylum Spirochaetes, and family Syntrophomonadaceae. Although Syntrophomonadaceae species are considered to be the major fatty acid-degrading syntrophic microorganisms under methanogenic conditions, they were detected in only two of the clone libraries. These results suggest that phylogenetically diverse bacterial groups were active in situ in the degradation of LCFA under methanogenic conditions.

scholarly journals Microbial Communities Involved in Anaerobic Degradation of Unsaturated or Saturated Long-Chain Fatty Acids

2006 ◽  
Vol 73 (4) ◽  
pp. 1054-1064 ◽  
Author(s):  
Diana Z. Sousa ◽  
M. Alcina Pereira ◽  
Alfons J. M. Stams ◽  
M. Madalena Alves ◽  
Hauke Smidt
Keyword(s):  
Fatty Acid ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Enrichment Culture ◽  
Methane Yield ◽  
Rrna Gene ◽  
Microbial Composition ◽  
Dgge Profile ◽  
Enrichment Cultures ◽  
Long Chain

ABSTRACTAnaerobic long-chain fatty acid (LCFA)-degrading bacteria were identified by combining selective enrichment studies with molecular approaches. Two distinct enrichment cultures growing on unsaturated and saturated LCFAs were obtained by successive transfers in medium containing oleate and palmitate, respectively, as the sole carbon and energy sources. Changes in the microbial composition during enrichment were analyzed by denaturing gradient gel electrophoresis (DGGE) profiling of PCR-amplified 16S rRNA gene fragments. Prominent DGGE bands of the enrichment cultures were identified by 16S rRNA gene sequencing. A significant part of the retrieved 16S rRNA gene sequences was most similar to those of uncultured bacteria. Bacteria corresponding to predominant DGGE bands in oleate and palmitate enrichment cultures clustered with fatty acid-oxidizing bacteria withinSyntrophomonadaceaeandSyntrophobacteraceaefamilies. A low methane yield, corresponding to 9 to 18% of the theoretical value, was observed in the oleate enrichment, and acetate, produced according to the expected stoichiometry, was not further converted to methane. In the palmitate enrichment culture, the acetate produced was completely mineralized and a methane yield of 48 to 70% was achieved from palmitate degradation. Furthermore, the oleate enrichment culture was able to use palmitate without detectable changes in the DGGE profile. However, the palmitate-specialized consortia degraded oleate only after a lag phase of 3 months, after which the DGGE profile had changed. Two predominant bands appeared, and sequence analysis showed affiliation with theSyntrophomonasgenus. These bands were also present in the oleate enrichment culture, suggesting that these bacteria are directly involved in oleate degradation, emphasizing possible differences between the degradation of unsaturated and saturated LCFAs.

scholarly journals Sulfide level in municipal sludge digesters affects microbial community response to long-chain fatty acid loads

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Sepehr Shakeri Yekta ◽  
Tong Liu ◽  
Mette Axelsson Bjerg ◽  
Luka Šafarič ◽  
Anna Karlsson ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Microbial Community ◽  
Microbial Communities ◽  
Community Response ◽  
Chain Fatty Acid ◽  
Rrna Gene ◽  
Municipal Sludge ◽  
Long Chain Fatty Acid ◽  
Conversion Rates ◽  
Long Chain

Abstract Background Waste lipids are attractive substrates for co-digestion with primary and activated sewage sludge (PASS) to improve biogas production at wastewater treatment plants. However, slow conversion rates of long-chain fatty acids (LCFA), produced during anaerobic digestion (AD), limit the applicability of waste lipids as co-substrates for PASS. Previous observations indicate that the sulfide level in PASS digesters affects the capacity of microbial communities to convert LCFA to biogas. This study assessed the microbial community response to LCFA loads in relation to sulfide level during AD of PASS by investigating process performance and microbial community dynamics upon addition of oleate (C18:1) and stearate (C18:0) to PASS digesters at ambient and elevated sulfide levels. Results Conversion of LCFA to biogas was limited (30% of theoretical biogas potential) during continuous co-digestion with PASS, which resulted in further LCFA accumulation. However, the accumulated LCFA were converted to biogas (up to 66% of theoretical biogas potential) during subsequent batch-mode digestion, performed without additional substrate load. Elevated sulfide level stimulated oleate (but not stearate) conversion to acetate, but oleate and sulfide imposed a synergistic limiting effect on acetoclastic methanogenesis and biogas formation. Next-generation sequencing of 16S rRNA gene amplicons of bacteria and archaea showed that differences in sulfide level and LCFA type resulted in microbial community alterations with distinctly different patterns. Taxonomic profiling of the sequencing data revealed that the phylum Cloacimonetes is likely a key group during LCFA degradation in PASS digesters, where different members take part in degradation of saturated and unsaturated LCFA; genus W5 (family Cloacimonadaceae) and family W27 (order Cloacimonadales), respectively. In addition, LCFA-degrading Syntrophomonas, which is commonly present in lipid-fed digesters, increased in relative abundance after addition of oleate at elevated sulfide level, but not without sulfide or after stearate addition. Stearate conversion to biogas was instead associated with increasing abundance of hydrogen-producing Smithella and hydrogenotrophic Methanobacterium. Conclusions Long-chain fatty acid chain saturation and sulfide level are selective drivers for establishment of LCFA-degrading microbial communities in municipal sludge digesters.

scholarly journals Long-chain fatty acid-induced changes in gene expression in neonatal cardiac myocytes

2000 ◽  
Vol 41 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Karin A. J.M. van der Lee ◽  
Michaël M. Vork ◽  
Johan E. De Vries ◽  
Peter H.M. Willemsen ◽  
Jan F.C. Glatz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fatty Acid ◽  
Cardiac Myocytes ◽  
Chain Fatty Acid ◽  
Long Chain Fatty Acid ◽  
Induced Changes ◽  
Long Chain

Intestinal delivery in a long-chain fatty acid formulation enables lymphatic transport and systemic exposure of orlistat

2021 ◽  
Vol 596 ◽  
pp. 120247
Author(s):  
Given Lee ◽  
Sifei Han ◽  
Zijun Lu ◽  
Jiwon Hong ◽  
Anthony R.J. Phillips ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Systemic Exposure ◽  
Chain Fatty Acid ◽  
Lymphatic Transport ◽  
Long Chain Fatty Acid ◽  
Intestinal Delivery ◽  
Acid Formulation ◽  
Long Chain
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