Wax Esters in the Marine Environment: Origin and Composition of the Wax from Bute Inlet, British Columbia

1979 ◽  
Vol 36 (12) ◽  
pp. 1519-1523 ◽  
Author(s):  
Richard F. Lee ◽  
Judd C. Nevenzel
Keyword(s):  
British Columbia ◽  
Marine Pollution ◽  
Major Change ◽  
Dry Weight ◽  
Wax Esters ◽  
Wax Ester ◽  
Winter Temperatures ◽  
The World ◽  
Major Hydrocarbon ◽  
Fatty Acid Compositions

During severe winters large amounts of a solid lipid accumulate on the water surface and on the shores of Bute Inlet, a deep fjord on the mainland of British Columbia. Chromatographic analyses show that this wax consists chiefly of wax esters (48%), with minor amounts of hydrocarbons (4%) and triacylglycerols (6%). Dominant among the zooplankton in this inlet is the copepod Calanus plumchrus, which also is rich in wax esters (40–50% of dry weight). Except for the lack of polyunsaturation in Bute Inlet wax there is a close similarity between the wax ester, alcohol, and fatty acid compositions of C. plumchrus and Bute Inlet wax. The major hydrocarbon of both is pristane. We hypothesize that Bute Inlet wax is produced by some major change in water conditions which cause a massive kill of copepods. At winter temperatures this lipid is a solid and as such may accumulate on the beach. Copepods are the likely source for the wax esters in slicks and sediments reported from oceanic areas throughout the world. Key words: marine pollution, biological pollutant, lipid, hydrocarbon, wax, zooplankton, Copepoda

scholarly journals A Fatty Acyl Coenzyme A Reductase Promotes Wax Ester Accumulation in Rhodococcus jostii RHA1

2017 ◽  
Vol 83 (20) ◽  
Author(s):  
James Round ◽  
Raphael Roccor ◽  
Shu-Nan Li ◽  
Lindsay D. Eltis
Keyword(s):  
Specific Activity ◽  
Dry Weight ◽  
Fatty Acyl ◽  
Wax Esters ◽  
Wax Ester ◽  
Wild Type ◽  
Considerable Potential ◽  
Commodity Chemicals ◽  
Acyl Coenzyme A ◽  
Rhodococcus Jostii

ABSTRACT Many rhodococci are oleaginous and, as such, have considerable potential for the sustainable production of lipid-based commodity chemicals. Herein, we demonstrated that Rhodococcus jostii RHA1, a soil bacterium that catabolizes a wide range of organic compounds, produced wax esters (WEs) up to 0.0002% of its cellular dry weight during exponential growth on glucose. These WEs were fully saturated and contained primarily 31 to 34 carbon atoms. Moreover, they were present at higher levels during exponential growth than under lipid-accumulating conditions. Bioinformatics analyses revealed that RHA1 contains a gene encoding a putative fatty acyl coenzyme A (acyl-CoA) reductase (FcrA). The purified enzyme catalyzed the NADPH-dependent transformation of stearoyl-CoA to stearyl alcohol with a specific activity of 45 ± 3 nmol/mg · min and dodecanal to dodecanol with a specific activity of 5,300 ± 300 nmol/mg · min. Deletion of fcrA did not affect WE accumulation when grown in either carbon- or nitrogen-limited medium. However, the ΔfcrA mutant accumulated less than 20% of the amount of WEs as the wild-type strain under conditions of nitric oxide stress. A strain of RHA1 overproducing FcrA accumulated WEs to ∼13% cellular dry weight under lipid-accumulating conditions, and their acyl moieties had longer average chain lengths than those in wild-type cells (C17 versus C16). The results provide insight into the biosynthesis of WEs in rhodococci and facilitate the development of this genus for the production of high-value neutral lipids. IMPORTANCE Among the best-studied oleaginous bacteria, rhodococci have considerable potential for the sustainable production of lipid-based commodity chemicals, such as wax esters. However, many aspects of lipid synthesis in these bacteria are poorly understood. The current study identifies a key enzyme in wax ester synthesis in rhodococci and exploits it to significantly improve the yield of wax esters in bacteria. In so doing, this work contributes to the development of novel bioprocesses for an important class of oleochemicals that may ultimately allow us to phase out their unsustainable production from sources such as petroleum and palm oil.

On the nutrition and metabolism of zooplankton XI. Lipids in Calanus helgolandicus grazing Biddulphia sinensis

1977 ◽  
Vol 57 (2) ◽  
pp. 525-533 ◽  
Author(s):  
J. R. Sargent ◽  
R. R. Gatten ◽  
E. D. S. Corner ◽  
C. C. Kilvington
Keyword(s):  
Brood Size ◽  
Developmental Stages ◽  
Dry Weight ◽  
Wax Esters ◽  
Wax Ester ◽  
Calanoid Copepods ◽  
Lipid Levels ◽  
History Of ◽  
Northern Pacific

Many of the calanoid copepods contain large amounts of neutral lipid that is predominantly wax esters (Lee, Hirota & Barnett, 1971; Lee & Hirota, 1973; Sargent & Garten, 1976). The role of these compounds in the life-history of copepods is particularly well documented for the large Northern Pacific calanoid Euchaeta japonica Marukawa. These animals have their highest levels of total lipid (50% of the dry weight) at stage V, up to 80% being wax esters (Lee, Nevenzel & Lewis, 1974). Wax ester levels are lower in adult females but are high in the eggs, the contents of which are subsequently used during the naupliar stages (Lee et al. 1974). Thus, wax esters accumulated during the later developmental stages provide a fuel for the developing eggs and embryos; from which it follows that the amounts of these lipids present in mature animals are likely to be critical in determining the brood size and survival of the ensuing generation. So far, however, the factors controlling lipid levels in copepods have been poorly understood.

scholarly journals Dynamic decoupling of biomass and lipid biosynthesis by autonomously regulated switch

2018 ◽  
Author(s):  
Suvi Santala ◽  
Elena Efimova ◽  
Ville Santala
Keyword(s):  
Isocitrate Lyase ◽  
Glucose Dehydrogenase ◽  
Lipid Synthesis ◽  
Dry Weight ◽  
Carbon Flow ◽  
Wax Esters ◽  
Wax Ester ◽  
Acinetobacter Baylyi ◽  
Metabolic Switch ◽  
Engineered Strain

For improving the microbial production of fuels and chemicals, gene knock-outs and overexpression are routinely applied to intensify the carbon flow from substrate to product. However, their possibilities in dynamic control of the flux between the biomass and product synthesis are limited, whereas dynamic metabolic switches can be used for optimizing the distribution of carbon and resources. The production of single cell oils is especially challenging, as the synthesis is strongly regulated, competes directly with biomass, and requires defined conditions, such as nitrogen limitation. Here, we engineered a metabolic switch for redirecting carbon flow from biomass to wax ester production in Acinetobacter baylyi ADP1 using acetate as a carbon source. Isocitrate lyase, an essential enzyme for growth on acetate, was expressed under an arabinose inducible promoter. The autonomous downregulation of the expression is based on the gradual oxidation of the arabinose inducer by a glucose dehydrogenase gcd. The depletion of the inducer, occurring simultaneously to acetate consumption, switches the cells from a biomass mode to a lipid synthesis mode, enabling the efficient channelling of carbon to wax esters in a simple batch culture. In the engineered strain, the yield and titer of wax esters were improved by 3.8 and 3.1 folds, respectively, over the control strain. In addition, the engineered strain accumulated wax esters 19% of cell dry weight, being the highest reported among microbes. The study provides important insights into the dynamic engineering of the biomass-dependent synthesis pathways for the improved production of biocompounds from low-cost, sustainable substrates.

The lipid, fatty acid and fatty alcohol composition of the myctophid fish Electrona antarctica: high level of wax esters and food-chain implications

1997 ◽  
Vol 9 (3) ◽  
pp. 258-265 ◽  
Author(s):  
Charles F. Phleger ◽  
Peter D. Nichols ◽  
Patti Virtue
Keyword(s):  
Fatty Acids ◽  
Total Lipid ◽  
Dry Weight ◽  
Monounsaturated Fatty Acids ◽  
Wax Esters ◽  
Wax Ester ◽  
Lipid Fatty Acid ◽  
Myctophid Fish ◽  
High Level ◽  
Elephant Island

The myctophid, Electrona antarctica, was collected by trawl from the Elephant Island region of the Antarctic Peninsula, and from East Antarctica near 61°S and 93°W. Total lipid was higher in Elephant Island E. antarctica (whole fish, 466–585 mg g−1 dry weight) than those from Eastern Antarctica (394–459 mg g−1). Wax esters comprised 86.2–90.5% of total lipid in E. antarctica flesh. There were no significant differences between Eastern Antarctica and Elephant Island in total wax ester levels, or in levels of wax esters between different tissues analysed. Oily bones (up to 326 mg g−1 in the neurocranium) characterized E. antarctica from both locations, with wax esters as the major skeletal lipid class (67.0–87.9%, percent of lipid). The wax esters may have a buoyancy role in E. antarctica. The only substantial amount of triacylglycerols (29.4%) were found in the viscera of Elephant Island fish. The principal fatty acids of all fish analysed included the monounsaturated fatty acids 18:1(n-9) and 16:1(n-7), with lower levels of 16:0 and 14:0 saturated acids. Fatty alcohols were dominated by the saturated 16:0 and 14:0 (37.8–47.8%) and the monounsaturated 18:1(n-9) and 18:1(n-7) (38.3–59.2%). The low ratio of 22:1/20:1 alcohols observed for E. antarctica is consistent with a diet of amphipods, copepods and other items low in 22:1 alcohols.

Forest health and climate change: A British Columbia perspective

2010 ◽  
Vol 86 (4) ◽  
pp. 412-422 ◽  
Author(s):  
Alex J. Woods ◽  
Don Heppner ◽  
Harry H. Kope ◽  
Jennifer Burleigh ◽  
Lorraine Maclauchlan
Keyword(s):  
Climate Change ◽  
British Columbia ◽  
Mountain Pine Beetle ◽  
Forest Health ◽  
Forest Insects ◽  
Pine Beetle ◽  
The World ◽  
Dothistroma Needle Blight ◽  
Management Recommendations ◽  
Needle Blight

BC’s forests have already faced two simultaneous, globally significant, epidemics linked to climate change; the Dothistroma needle blight epidemic in NW BC and the massive mountain pine beetle epidemic throughout the BC Interior. Building on these experiences, we have compiled our best estimates of how we believe other forest health agents may behave as climate change continues to influence our forests. We have drawn on literature from around the world but have focused on the situation in BC. We have made management recommendations based on what we have seen so far and what we expect to come.Key words: climate change, forest health, forest insects, forest pathogens, forest management, British Columbia

scholarly journals Do minke whales (Balaenoptera acutorostrata) digest wax esters?

1995 ◽  
Vol 74 (5) ◽  
pp. 717-722 ◽  
Author(s):  
Erling S. Nordøy
Keyword(s):  
Energy Density ◽  
Dry Matter ◽  
General Pattern ◽  
Dry Mass ◽  
Wax Esters ◽  
Gut Contents ◽  
Wax Ester ◽  
Balaenoptera Acutorostrata ◽  
Minke Whales

Mammals are known to utilize wax esters with an efficiency of less than 50%. The purpose of the present study was to examine whether or not minke whales (Balaenoptera acutorostrata), which at times may eat considerable amounts of wax-ester-rich krill, represent an exception to this general pattern. Samples of fresh undigested forestomach, as well as colon, contents were obtained from minke whales (n5) that had been feeding on krill (Thysanoessa inermis) for some time. The samples were analysed for dry mass, energy density, lipid content and the major lipid classes, including wax esters. The concentrations of wax esters were compared with previous estimates of dry-matter disappearance of the same type of prey using anin vitrotechnique, to calculate the dry-matter digestibility of wax esters (DMDwax). Wax esters contributed 21% of the energy and 47% of total lipids in the krill diet. The energy density of gut contents decreased by 50% after their passage from forestomach to the end of the colon. The DMDwaxwas 94·1 (SD 2·8)% (n5). This high DMDwaxand the occurrence of fatty alcohols, one of the products of wax-ester hydrolysis, in faeces show that minke whales are very efficient digesters of wax esters and absorb most of the energy-rich products of this process.

scholarly journals Isolation and Characterization of a Mutant of the Marine Bacterium Alcanivorax borkumensis SK2 Defective in Lipid Biosynthesis

2010 ◽  
Vol 76 (9) ◽  
pp. 2884-2894 ◽  
Author(s):  
Efraín Manilla-Pérez ◽  
Alvin Brian Lange ◽  
Stephan Hetzler ◽  
Marc Wältermann ◽  
Rainer Kalscheuer ◽  
...  
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
Marine Bacterium ◽  
Neutral Lipids ◽  
Nile Red ◽  
Dry Weight ◽  
Wax Ester ◽  
Gene Encoding ◽  
Isolation And Characterization ◽  
Key Enzyme

ABSTRACT In many microorganisms, the key enzyme responsible for catalyzing the last step in triacylglycerol (TAG) and wax ester (WE) biosynthesis is an unspecific acyltransferase which is also referred to as wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT; AtfA). The importance and function of two AtfA homologues (AtfA1 and AtfA2) in the biosynthesis of TAGs and WEs in the hydrocarbon-degrading marine bacterium Alcanivorax borkumensis SK2 have been described recently. However, after the disruption of both the AtfA1 and AtfA2 genes, reduced but substantial accumulation of TAGs was still observed, indicating the existence of an alternative TAG biosynthesis pathway. In this study, transposon-induced mutagenesis was applied to an atfA1 atfA2 double mutant to screen for A. borkumensis mutants totally defective in biosynthesis of neutral lipids in order to identify additional enzymes involved in the biosynthesis of these lipids. At the same time, we have searched for a totally TAG-negative mutant in order to study the function of TAGs in A. borkumensis. Thirteen fluorescence-negative mutants were identified on Nile red ONR7a agar plates and analyzed for their abilities to synthesize lipids. Among these, mutant 2 M131 was no longer able to synthesize and accumulate TAGs if pyruvate was used as the sole carbon source. The transposon insertion was localized in a gene encoding a putative cytochrome c family protein (ABO_1185). Growth and TAG accumulation experiments showed that the disruption of this gene resulted in the absence of TAGs in 2 M131 but that growth was not affected. In cells of A. borkumensis SK2 grown on pyruvate as the sole carbon source, TAGs represented about 11% of the dry weight of the cells, while in the mutant 2 M131, TAGs were not detected by thin-layer and gas chromatography analyses. Starvation and lipid mobilization experiments revealed that the lipids play an important role in the survival of the cells. The function of neutral lipids in A. borkumensis SK2 is discussed.

scholarly journals Comparative Gene Genealogies Indicate that Two Clonal Lineages of Cryptococcus gattii in British Columbia Resemble Strains from Other Geographical Areas

2005 ◽  
Vol 4 (10) ◽  
pp. 1629-1638 ◽  
Author(s):  
Sarah E. Kidd ◽  
Hong Guo ◽  
Karen H. Bartlett ◽  
Jianping Xu ◽  
James W. Kronstad
Keyword(s):  
British Columbia ◽  
Population Structure ◽  
Nucleotide Sequence ◽  
Global Scale ◽  
Cryptococcus Gattii ◽  
Temperate Climate ◽  
Molecular Type ◽  
Sequence Comparisons ◽  
The World ◽  
Clonal Population Structure

ABSTRACT Cryptococcus gattii has recently emerged as a pathogen of humans and animals in the temperate climate of Vancouver Island, British Columbia (B.C.). The majority (∼95%) of the isolates from the island belong to the VGII molecular type, and the remainder belong to the VGI molecular type. The goals of this study were to compare patterns of molecular variation among C. gattii isolates from B.C. with those from different areas of the world and to investigate the population structure using a comparative gene genealogy approach. Our results indicate that the C. gattii population in B.C. comprises at least two divergent lineages, corresponding to previously identified VGI and VGII molecular types. The genealogical analysis of strains suggested a predominantly clonal population structure among B.C. isolates, while there was evidence for sexual recombination between different molecular types on a global scale. We found no geographic pattern of strain relationships, and nucleotide sequence comparisons revealed that genotypes among isolates from B.C. were also present among isolates from other areas of the world, indicating extensive strain dispersal. The nucleotide sequence diversity among isolates from B.C. was similar to that among isolates from other areas of the world.

Directions and Opportunities in Health Informatics in British Columbia

1994 ◽  
Vol 33 (03) ◽  
pp. 299-301
Author(s):  
K. Thornton
Keyword(s):  
Health Care ◽  
British Columbia ◽  
Health Care Providers ◽  
Health Informatics ◽  
Major Change ◽  
Network Evolution ◽  
Royal Commission ◽  
Social Changes ◽  
Care Providers ◽  
The Social

Abstract:The social changes, and changes in perceptions of the effectiveness of health care in British Columbia have resulted in a large number of recommendations in the report of the British Columbia Royal Commission on Health Care and Costs. Many of these recommendations have implications for health informatics. The British Columbia Government, in outlining a response, foresees a major change in the emphases of health care, which will involve four major areas of health informatics: network evolution, automation of the patient record, outcome- and other quality-related databases, and consumer health education. These themes are discussed, in the light of the opinions of academics, health care providers, and the health-informatics industry. The themes must be intercalated into the health informatics curriculum, to equip graduates for the challenges of B.C.’s changing health care system.

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