Monounsaturated but Not Polyunsaturated Fatty Acids Are Required for Growth of the Deep-Sea BacteriumPhotobacterium profundum SS9 at High Pressure and Low Temperature

1999 ◽  
Vol 65 (4) ◽  
pp. 1710-1720 ◽  
Author(s):  
Eric E. Allen ◽  
Daniel Facciotti ◽  
Douglas H. Bartlett
Keyword(s):  
Fatty Acids ◽  
High Pressure ◽  
Fatty Acid ◽  
Low Temperature ◽  
Mutant Strain ◽  
Deep Sea ◽  
High Pressures ◽  
Unsaturated Fatty Acids ◽  
Temperature Sensitive ◽  
Pressure Sensitive

ABSTRACT There is considerable evidence correlating the production of increased proportions of membrane unsaturated fatty acids (UFAs) with bacterial growth at low temperatures or high pressures. In order to assess the importance of UFAs to microbial growth under these conditions, the effects of conditions altering UFA levels in the psychrotolerant piezophilic deep-sea bacterium Photobacterium profundum SS9 were investigated. The fatty acids produced byP. profundum SS9 grown at various temperatures and pressures were characterized, and differences in fatty acid composition as a function of phase growth, and between inner and outer membranes, were noted. P. profundum SS9 was found to exhibit enhanced proportions of both monounsaturated (MUFAs) and polyunsaturated (PUFAs) fatty acids when grown at a decreased temperature or elevated pressure. Treatment of cells with cerulenin inhibited MUFA but not PUFA synthesis and led to a decreased growth rate and yield at low temperature and high pressure. In addition, oleic acid-auxotrophic mutants were isolated. One of these mutants, strain EA3, was deficient in the production of MUFAs and was both low-temperature sensitive and high-pressure sensitive in the absence of exogenous 18:1 fatty acid. Another mutant, strain EA2, produced little MUFA but elevated levels of the PUFA species eicosapentaenoic acid (EPA; 20:5n-3). This mutant grew slowly but was not low-temperature sensitive or high-pressure sensitive. Finally, reverse genetics was employed to construct a mutant unable to produce EPA. This mutant, strain EA10, was also not low-temperature sensitive or high-pressure sensitive. The significance of these results to the understanding of the role of UFAs in growth under low-temperature or high-pressure conditions is discussed.

scholarly journals Role and Regulation of Fatty Acid Biosynthesis in the Response of Shewanella piezotolerans WP3 to Different Temperatures and Pressures

2009 ◽  
Vol 191 (8) ◽  
pp. 2574-2584 ◽  
Author(s):  
Feng Wang ◽  
Xiang Xiao ◽  
Hong-Yu Ou ◽  
Yingbao Gai ◽  
Fengping Wang
Keyword(s):  
Fatty Acids ◽  
High Pressure ◽  
Fatty Acid ◽  
Low Temperature ◽  
Gene Cluster ◽  
Fatty Acid Synthesis ◽  
Fatty Acid Biosynthesis ◽  
Acid Synthesis ◽  
Different Temperatures ◽  
Branched Chain

ABSTRACT Members of the genus Shewanella inhabit various environments; they are capable of synthesizing various types of low-melting-point fatty acids, including monounsaturated fatty acids (MUFA) and branched-chain fatty acids (BCFA) with and without eicosapentanoic acid (EPA). The genes involved in fatty acid synthesis in 15 whole-genome-sequenced Shewanella strains were identified and compared. A typical type II fatty acid synthesis pathway in Shewanella was constructed. A complete EPA synthesis gene cluster was found in all of the Shewanella genomes, although only a few of them were found to produce EPA. The roles and regulation of fatty acids synthesis in Shewanella were further elucidated in the Shewanella piezotolerans WP3 response to different temperatures and pressures. The EPA and BCFA contents of WP3 significantly increased when it was grown at low temperature and/or under high pressure. EPA, but not MUFA, was determined to be crucial for its growth at low temperature and high pressure. A gene cluster for a branched-chain amino acid ABC transporter (LIV-I) was found to be upregulated at low temperature. Combined approaches, including mutagenesis and an isotopic-tracer method, revealed that the LIV-I transporter played an important role in the regulation of BCFA synthesis in WP3. The LIV-I transporter was identified only in the cold-adapted Shewanella species and was assumed to supply an important strategy for Shewanella cold adaptation. This is the first time the molecular mechanism of BCFA regulation in bacteria has been elucidated.

scholarly journals Influence of Ice Encasement and Ethylene Regulation on Cellular-protection Responses in Annual Bluegrass

2021 ◽  
pp. 1-12
Author(s):  
Kevin Laskowski ◽  
Emily Merewitz
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Low Temperature ◽  
Unsaturated Fatty Acid ◽  
Acid Content ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Content ◽  
Plant Tissues ◽  
Annual Bluegrass ◽  
Ice Encasement

Annual bluegrass (Poa annua var. reptans), when grown as a putting green species, is sensitive to winter injury such as ice cover. Inhibiting plant ethylene production could be a way to improve annual bluegrass tolerance of ice encasement. The goals of this study were to determine how winter conditions and ethylene regulatory treatments affect the antioxidant system, fatty acid composition, and apoplastic proteins of annual bluegrass plant tissues. Ethylene-promotive (1-aminocyclopropane-1-carboxylic acid or ethephon) and ethylene inhibition treatments [aminoethoxyvinylglycine (AVG)] were applied to plants in the field during acclimation. Plant plugs were taken and subjected to low temperature (−4 °C) and ice-encasement treatments in growth chamber conditions. Antioxidant activities of ascorbate peroxidase (APX), peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) were measured along with malondialdehyde content (MDA) and apoplastic protein content in leaf and crown tissue. Saturated and unsaturated fatty acid contents were measured in leaf, crown, and root tissue. Higher unsaturated fatty acids are often associated with greater low-temperature tolerance. Compared with the untreated controls, ethephon-treated annual bluegrass had greater MDA contents, lower POD and SOD activity, and greater saturated and decreased unsaturated fatty acids. Ethylene inhibition treatments caused annual bluegrass to have less saturated fatty acid content and greater unsaturated fatty acid content, a greater content of apoplast proteins, and higher CAT activity when compared with the untreated controls. The activity of APX was greater in AVG-treated annual bluegrass than in controls. Ethylene may reduce physiological health overwinter, and inhibitory treatments may promote winter tolerance by promoting antioxidant activity, apoplast proteins, and the content of unsaturated fatty acids in plant tissues.

scholarly journals Large-Scale Transposon Mutagenesis of Photobacterium profundum SS9 Reveals New Genetic Loci Important for Growth at Low Temperature and High Pressure

2007 ◽  
Vol 190 (5) ◽  
pp. 1699-1709 ◽  
Author(s):  
Federico M. Lauro ◽  
Khiem Tran ◽  
Alessandro Vezzi ◽  
Nicola Vitulo ◽  
Giorgio Valle ◽  
...  
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Deep Sea ◽  
Large Scale ◽  
High Pressures ◽  
Cell Envelope ◽  
Transposon Mutagenesis ◽  
Chromosomal Structure ◽  
And Function ◽  
Photobacterium Profundum

ABSTRACT Microorganisms adapted to piezopsychrophilic growth dominate the majority of the biosphere that is at relatively constant low temperatures and high pressures, but the genetic bases for the adaptations are largely unknown. Here we report the use of transposon mutagenesis with the deep-sea bacterium Photobacterium profundum strain SS9 to isolate dozens of mutant strains whose growth is impaired at low temperature and/or whose growth is altered as a function of hydrostatic pressure. In many cases the gene mutation-growth phenotype relationship was verified by complementation analysis. The largest fraction of loci associated with temperature sensitivity were involved in the biosynthesis of the cell envelope, in particular the biosynthesis of extracellular polysaccharide. The largest fraction of loci associated with pressure sensitivity were involved in chromosomal structure and function. Genes for ribosome assembly and function were found to be important for both low-temperature and high-pressure growth. Likewise, both adaptation to temperature and adaptation to pressure were affected by mutations in a number of sensory and regulatory loci, suggesting the importance of signal transduction mechanisms in adaptation to either physical parameter. These analyses were the first global analyses of genes conditionally required for low-temperature or high-pressure growth in a deep-sea microorganism.

scholarly journals A role for unsaturated fatty acids in mitochondrial movement and inheritance.

1991 ◽  
Vol 115 (5) ◽  
pp. 1249-1257 ◽  
Author(s):  
L C Stewart ◽  
M P Yaffe
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Prolonged Incubation ◽  
Mitochondrial Movement ◽  
Mitochondrial Transfer ◽  
Mitochondrial Distribution

Yeast cells with the mdm2 mutation display temperature-sensitive growth and defective intracellular mitochondrial movement at the non-permissive temperature. The latter phenotype includes both an absence of mitochondrial transfer into daughter buds of mitotically growing cells and an aberrant mitochondrial distribution in cells exposed to mating pheromone. The wild-type MDM2 gene was cloned by complementation, and DNA sequence analysis revealed a large open reading frame encoding a putative protein of 58.4 kD. The predicted protein sequence is identical to that reported for the yeast OLE1 gene encoding fatty acid desaturase. Unsaturated fatty acid levels are substantially decreased in mdm2 cells after a prolonged incubation at the non-permissive temperature. The addition of oleic acid complements the temperature-sensitive growth and mitochondrial distribution defects of the mutant cells. These results indicate that mdm2 is a temperature-sensitive allele of OLE1 and demonstrate an essential role for unsaturated fatty acids in mitochondrial movement and inheritance.

scholarly journals Overexpression of yccL (gnsA) andydfY (gnsB) Increases Levels of Unsaturated Fatty Acids and Suppresses both the Temperature-SensitivefabA6 Mutation and Cold-SensitivesecG Null Mutation of Escherichia coli

2001 ◽  
Vol 183 (19) ◽  
pp. 5523-5528 ◽  
Author(s):  
Rie Sugai ◽  
Hisayo Shimizu ◽  
Ken-ichi Nishiyama ◽  
Hajime Tokuda
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Low Temperature ◽  
Unsaturated Fatty Acid ◽  
Cold Shock ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Content ◽  
Null Mutation ◽  
Null Mutant ◽  
Multicopy Suppressor

ABSTRACT A multicopy suppressor of the cold-sensitive secGnull mutation was isolated. The suppressor containedsfa and yccL, the former of which has been reported to be a multicopy suppressor of the fabA6mutation carried by a temperature-sensitive unsaturated fatty acid auxotroph. Subcloning of the suppressor gene revealed thatyccL, renamed gnsA (secGnull mutant suppressor), was responsible for the suppression of both the secG null mutation and the fabA6mutation. In contrast, the sfa gene did not suppress thefabA6 mutation. The ydfY(gnsB) gene, encoding a protein which is highly similar to GnsA, also suppressed both the secG null mutation and the fabA6 mutation. Although both gnsAand gnsB are linked to cold shock genes, the levels of GnsA and GnsB did not exhibit a cold shock response. AgnsA-gnsB double null mutant grew normally under all conditions examined; thus, the in vivo functions of gnsAand gnsB remain unresolved. However, overexpression of gnsA and gnsBstimulated proOmpA translocation of the secG null mutant at low temperature and caused a significant increase in the unsaturated fatty acid content of phospholipids. Taken together, these results suggest that an increase in membrane fluidity due to the increase in unsaturated fatty acids compensates for the absence of the SecG function, especially at low temperature.

EFFECT OF GINGER, LEMURU FISH OIL SAPONIFICATION AND OLIVE OIL ON COMPOSITION FATTY ACID OF BEEF

2014 ◽  
Vol 4 (1) ◽  
pp. 31-39
Author(s):  
Siwitri Kadarsih
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fish Oil ◽  
Olive Oil ◽  
Rice Bran ◽  
Dry Matter ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Omega 3 ◽  
Omega 6

The objective was to get beef that contain unsaturated fatty acids (especially omega 3 and 6), so as to improve intelligence, physical health for those who consume. The study design using CRD with 3 treatments, each treatment used 4 Bali cattle aged approximately 1.5 years. Observations were made 8 weeks. Pasta mixed with ginger provided konsentrat. P1 (control); P2 (6% saponification lemuru fish oil, olive oil 1%; rice bran: 37.30%; corn: 62.70%; KLK: 7%, ginger paste: 100 g); P3 (lemuru fish oil saponification 8%, 2% olive oil; rice bran; 37.30; corn: 62.70%; KLK: 7%, ginger paste: 200 g). Konsentrat given in the morning as much as 1% of the weight of the cattle based on dry matter, while the grass given a minimum of 10% of the weight of livestock observation variables include: fatty acid composition of meat. Data the analyzies qualitative. The results of the study showed that the composition of saturated fatty acids in meat decreased and an increase in unsaturated fatty acids, namely linoleic acid (omega 6) and linolenic acid (omega 3), and deikosapenta deikosaheksa acid.Keywords : 

scholarly journals Explore the gene network regulating the composition of fatty acids in cottonseed

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lihong Ma ◽  
Xinqi Cheng ◽  
Chuan Wang ◽  
Xinyu Zhang ◽  
Fei Xue ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Gene Network ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Accumulation Pattern ◽  
Time Points ◽  
Expression Characteristics

Abstract Background Cottonseed is one of the major sources of vegetable oil. Analysis of the dynamic changes of fatty acid components and the genes regulating the composition of fatty acids of cottonseed oil is of great significance for understanding the biological processes underlying biosynthesis of fatty acids and for genetic improving the oil nutritional qualities. Results In this study, we investigated the dynamic relationship of 13 fatty acid components at 12 developmental time points of cottonseed (Gossypium hirsutum L.) and generated cottonseed transcriptome of the 12 time points. At 5–15 day post anthesis (DPA), the contents of polyunsaturated linolenic acid (C18:3n-3) and saturated stearic acid (C18:0) were higher, while linoleic acid (C18:2n-6) was mainly synthesized after 15 DPA. Using 5 DPA as a reference, 15,647 non-redundant differentially expressed genes were identified in 10–60 DPA cottonseed. Co-expression gene network analysis identified six modules containing 3275 genes significantly associated with middle-late seed developmental stages and enriched with genes related to the linoleic acid metabolic pathway and α-linolenic acid metabolism. Genes (Gh_D03G0588 and Gh_A02G1788) encoding stearoyl-ACP desaturase were identified as hub genes and significantly up-regulated at 25 DPA. They seemed to play a decisive role in determining the ratio of saturated fatty acids to unsaturated fatty acids. FAD2 genes (Gh_A13G1850 and Gh_D13G2238) were highly expressed at 25–50 DPA, eventually leading to the high content of C18:2n-6 in cottonseed. The content of C18:3n-3 was significantly decreased from 5 DPA (7.44%) to 25 DPA (0.11%) and correlated with the expression characteristics of Gh_A09G0848 and Gh_D09G0870. Conclusions These results contribute to our understanding on the relationship between the accumulation pattern of fatty acid components and the expression characteristics of key genes involved in fatty acid biosynthesis during the entire period of cottonseed development.

scholarly journals A non-canonical Δ9-desaturase synthesizing palmitoleic acid identified in the thraustochytrid Aurantiochytrium sp. T66

2021 ◽  
Author(s):  
E-Ming Rau ◽  
Inga Marie Aasen ◽  
Helga Ertesvåg
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Palmitoleic Acid ◽  
Unsaturated Fatty Acids ◽  
Gene Annotation ◽  
Vaccenic Acid ◽  
Strain Engineering ◽  
Δ9 Desaturase ◽  
Δ12 Desaturase

Abstract Thraustochytrids are oleaginous marine eukaryotic microbes currently used to produce the essential omega-3 fatty acid docosahexaenoic acid (DHA, C22:6 n-3). To improve the production of this essential fatty acid by strain engineering, it is important to deeply understand how thraustochytrids synthesize fatty acids. While DHA is synthesized by a dedicated enzyme complex, other fatty acids are probably synthesized by the fatty acid synthase, followed by desaturases and elongases. Which unsaturated fatty acids are produced differs between different thraustochytrid genera and species; for example, Aurantiochytrium sp. T66, but not Aurantiochytrium limacinum SR21, synthesizes palmitoleic acid (C16:1 n-7) and vaccenic acid (C18:1 n-7). How strain T66 can produce these fatty acids has not been known, because BLAST analyses suggest that strain T66 does not encode any Δ9-desaturase-like enzyme. However, it does encode one Δ12-desaturase-like enzyme. In this study, the latter enzyme was expressed in A. limacinum SR21, and both C16:1 n-7 and C18:1 n-7 could be detected in the transgenic cells. Our results show that this desaturase, annotated T66Des9, is a Δ9-desaturase accepting C16:0 as a substrate. Phylogenetic studies indicate that the corresponding gene probably has evolved from a Δ12-desaturase-encoding gene. This possibility has not been reported earlier and is important to consider when one tries to deduce the potential a given organism has for producing unsaturated fatty acids based on its genome sequence alone. Key points • In thraustochytrids, automatic gene annotation does not always explain the fatty acids produced. • T66Des9 is shown to synthesize palmitoleic acid (C16:1 n-7). • T66des9 has probably evolved from Δ12-desaturase-encoding genes.

scholarly journals Meat Quality, Fatty Acid Content and NMR Metabolic Profile of Dorper Sheep Supplemented with Bypass Fats

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1133
Author(s):  
Atique Ahmed Behan ◽  
Muhammad Tayyab Akhtar ◽  
Teck Chwen Loh ◽  
Sharida Fakurazi ◽  
Ubedullah Kaka ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Meat Quality ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Fatty Acid Content ◽  
Basal Diet ◽  
Negative Influence ◽  
Significant Difference ◽  
Dorper Sheep

The supplementation of rumen bypass fat (RBF) has remained one of the preferred approaches used to decrease undesirable saturated fatty acids (FA) and increase beneficial unsaturated FA in the meat. This study was planned to evaluate the influences of rumen bypass fats on meat quality, fatty acid and metabolic profiles in male Dorper sheep (n = 36) with 24.66 ± 0.76 kg (mean ± standard error) initial body weight. Treatment comprised a basal diet (30:70 rice straw to concentrate) with no added RBF as a control (CON), basal diet with prilled fat (PF), basal diet with prilled fat plus lecithin (PFL) and basal diet with calcium soap of palm fatty acids (CaS). The findings revealed that cooking loss, drip loss and shear force in longissimus dorsi (LD) muscle were not affected by RBF supplementation, while meat pH was significantly higher in the CaS on aging day 1. However, the diet supplemented with prilled fat and lecithin modified the meat’s fatty acid profile significantly by increasing unsaturated fatty acids and decreasing saturated fats. The relative quantification of the major differentiating metabolites found in LD muscle of sheep showed that total cholesterol, esterified cholesterol, choline, glycerophosphocholine and glycerophospholipids were significantly lower in CaS and PFL diets, while glycerol and sphingomyelin were significantly higher in CaS and PFL diets. Most of the metabolites in the liver did not show any significant difference. Based on our results, the supplementation of protected fats did not have a negative influence on meat quality and the meat from Dorper sheep fed prilled fat with lecithin contained more healthy fatty acids compared to other diets.

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