Background: Delta-6 desaturase (FADS6) is a key bifunctional enzyme desaturating linoleic acid (LA) or α-linolenic acid (ALA) in the biosynthesis of polyunsaturated fatty acids (PUFAs). In previous work, we analyzed the substrate specificity of two FADS6 enzymes from Mortierella alpina ATCC 32222 (MaFADS6) and Micromonas pusilla CCMP1545 (MpFADS6), which showed preference for LA and ALA, respectively. We also clarified the PUFA profiles in M. alpina, where these lipids were synthesized mainly via the ω6 pathway and rarely via the ω3 pathway and as a result contained low ALA and eicosapentaenoic acid (EPA) levels.
Result: To enhance EPA production in M. alpina by favoring the ω3 pathway, a plasmid harboring the MpFADS6 gene was constructed and overexpressed in a uracil-auxotrophic strain of M. alpina using the Agrobacterium tumefaciens-mediated transformation (ATMT) method. Our results revealed that the EPA production reached 80.0 ± 15.0 and 90.4 ± 9.7 mg/L in MpFADS6 transformants grown at 28 and at 12 °C, respectively. To raise the level of ALA, free form fatty acid was used as exogenous substrate, which increased the EPA production up to 114.5 ± 12.4 mg/L. To reduce the cost of EPA production in M. alpina, peony seed oil (PSO) and peony seed meal (PSM) were used as source of ALA, and EPA production was improved to 149.3 ± 7.8 and 515.29 ± 32.66 mg/L by supplementing with 0.1 % PSO and 50 g/L PSM, respectively. The EPA yield was further increased to 588.5 ± 29.6 mg/L in a 5-L bioreactor, which resulted in a 26.2-fold increase compared to EPA production in wild-type M. alpina. In this work, we have significantly enhanced EPA production through overexpression of a FADS6 desaturase with preference for ALA, combined with supplementation of its substrate.
Conclusion: An ALA-preferring FADS6 from M. pusilla CCMP1545 was applied to enhance EPA production in M. alpina. By exogenous addition of peony seed oil or peony seed meal, EPA production was further increased in flasks and fermenters. This research also highlights the value of peony seed meal which can be converted to a high value-added product containing EPA, and as a way to increase the EPA/AA ratio in M. alpina.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4929779 | PMC |
http://dx.doi.org/10.1186/s12934-016-0516-5 | DOI Listing |
Curr Environ Health Rep
January 2025
Center for Public Health and Environmental Assessment, United States Environmental Protection Agency, 104 Mason Farm Rd., Chapel Hill, NC, 27514, USA.
Purpose Of Review: A major contributor to household air pollution (HAP) in sub-Saharan Africa (SSA) is unclean cooking fuel. Improved cookstove technology (ICT) interventions have been promoted as a solution, but their impacts on health are unclear. Our aim is to conduct a systematic review to explore the impacts of ICT interventions on health outcomes in SSA.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Department of Chemistry and Biochemistry, Concordia University, Montreal, Quebec H4B 1R6, Canada.
Coal tar-related products as a source of polycyclic aromatic compounds (PACs) are particularly concerning due to high PAC concentrations and inadequate source management. Benzo[b]carbazole, a benzocarbazole isomer exclusively found in coal tar-derived products, acts as an ideal marker to distinguish coal tar sources from others, enabling more robust quantification of coal tar contributions to PACs. To evaluate the historical and recent contributions of coal tar-related sources to the levels of PACs in Lake Ontario and associated ecological risk, we analyzed 31 PACs and 3 BCBz isomers in surface sediments and a sediment core.
View Article and Find Full Text PDFBiostatistics
December 2024
Department of Biostatistics, Yale University School of Public Health, 60 College Street, New Haven, CT06511, United States.
Evaluating air quality interventions is confronted with the challenge of interference since interventions at a particular pollution source likely impact air quality and health at distant locations, and air quality and health at any given location are likely impacted by interventions at many sources. The structure of interference in this context is dictated by complex atmospheric processes governing how pollution emitted from a particular source is transformed and transported across space and can be cast with a bipartite structure reflecting the two distinct types of units: (i) interventional units on which treatments are applied or withheld to change pollution emissions; and (ii) outcome units on which outcomes of primary interest are measured. We propose new estimands for bipartite causal inference with interference that construe two components of treatment: a "key-associated" (or "individual") treatment and an "upwind" (or "neighborhood") treatment.
View Article and Find Full Text PDFEnviron Pollut
January 2025
Department of Agronomy, Purdue University, West Lafayette, Indiana 47907, USA; Department of Environmental & Ecological Engineering, Purdue University, West Lafayette, Indiana 47907, USA; Ecological Sciences & Engineering Interdisciplinary Graduate Program, Purdue University, West Lafayette, Indiana 47907, USA.
Numerous unregulated organic compounds (UOCs) including pharmaceuticals, opioids, and personal care products (PCPs) end up in wastewater. UOC presence in biosolids (a wastewater treatment byproduct), which are applied to soil for different reasons raises environmental and health risk concerns. In this study, two multi-class extraction methods were developed and validated to target 111 UOCs from 8 different major families simultaneously in biosolids and biosolids-impacted soil.
View Article and Find Full Text PDFPoult Sci
January 2025
Institute for Egg Science and Technology, School of Food and Biological Engineering, Chengdu University, No. 2025 Chengluo Avenue, Chengdu 610106, China. Electronic address:
This study investigated the effects of sequential high-pressure homogenization followed by heat treatment on the physicochemical properties and lipidomic characteristics of liquid egg (LE) and liquid egg yolk (LEY). After treatment, homogenization and heat-treated liquid egg (H-LE) and homogenization and heat-treated liquid egg yolk (H-LEY) exhibited significantly enhanced flowability and thermal stability, with gelation temperatures increasing from 65°C to 82°C for H-LE and from 82°C to 95°C for H-LEY. In vitro digestion analysis revealed that H-LE demonstrated a 14.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!