Enzymatic purification of polyunsaturated fatty acids

Diverse uses of valuable seafood processing industry waste for sustainability: a review

Seafoods are rich in untapped bioactive compounds that have the potential to provide novel ingredients for the development of commercial functional foods and pharmaceuticals. Unfortunately, a large portion of waste or discards is generated in commercial processing setups (50-80%), which is wasted or underutilized. These by-products are a rich source of novel and valuable biomolecules, including bioactive peptides, collagen and gelatin, oligosaccharides, fatty acids, enzymes, calcium, water-soluble minerals, vitamins, carotenoids, chitin, chitosan and biopolymers. These fish components may be used in the food, cosmetic, pharmaceutical, environmental, biomedical and other industries. Furthermore, they provide a viable source for the production of biofuels. As a result, the current review emphasizes the importance of effective by-product and discard reduction techniques that can provide practical and profitable solutions. Recognizing this, many initiatives have been initiated to effectively use them and generate income for the long-term sustainability of the environment and economic framework of the processing industry. This comprehensive review summarizes the current state of the art in the sustainable valorisation of seafood by-products for human consumption. The review can generate a better understanding of the techniques for seafood waste valorisation to accelerate the sector while providing significant benefits.

Production of Omegas-6 and 9 from the Hydrolysis of Açaí and Buriti Oils by Lipase Immobilized on a Hydrophobic Support

This paper describes a bioprocess to obtain omegas-6 and 9 from the hydrolysis of Açaí (Euterpe oleracea Martius) and Buriti (Mauritia flexuosa) oils by lipases immobilized on octyl-sepharose. For this, oils and butters were initially selected as the carbon source which resulted in higher production of lipases in Beauveria bassiana and Fusarium oxysporum cultures. The carbon source that provided secretion of lipase by B. bassiana was Açaí oil, and for F. oxysporum, Bacuri butter. Lipases obtained under these conditions were immobilized on octyl-sepharose, and both, the derivatives and the crude extracts were biochemically characterized. It was observed that the immobilization promoted an increase of stability in B. bassiana and F. oxysporum lipase activities at the given temperatures and pH. In addition, the immobilization promoted hyperactivation of B. bassiana and F. oxysporum lipase activities being 23.5 and 11.0 higher than free enzyme, respectively. The hydrolysis of Açaí and Buriti oils by the derivatives was done in a biphasic (organic/aqueous) system, and the products were quantified in RP-HPLC. The results showed the potential of these immobilized lipases to obtain omegas-6 and 9 from Brazilian natural oils. This work may improve the enzymatic methodologies for obtaining foods and drugs enriched with fatty acids.

Separation of highly unsaturated fatty acid methyl esters from model bio-oils with ionic liquid-cosolvent as extractants

For the production of biodiesel, an IL-cosolvent extraction method was performed to separate value-added uFAMEs from model bio-oils.

Selective esterification to produce microalgal biodiesel and enrich polyunsaturated fatty acid using zeolite as a catalyst

A novel integrated process to produce microalgal biodiesel and simultaneously enrich high-value polyunsaturated fatty acids (PUFA) using selective catalyst.

Oral administration of eicosapentaenoic acid or docosahexaenoic acid modifies cardiac function and ameliorates congestive heart failure in male rats

This study assessed the effects of eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) on normal cardiac function (part 1) and congestive heart failure (CHF) (part 2) through electrocardiogram analysis and determination of EPA, DHA, and arachidonic acid (AA) concentrations in rat hearts. In part 2, pathologic assessments were also performed. For part 1 of this study, 4-wk-old male rats were divided into a control group and 2 experimental groups. The rats daily were orally administered (1 g/kg body weight) saline, EPA-ethyl ester (EPA-Et; E group), or DHA-ethyl ester (DHA-Et; D group), respectively, for 28 d. ECGs revealed that QT intervals were significantly shorter for groups E and D compared with the control group (P ≤ 0.05). Relative to the control group, the concentration of EPA was higher in the E group and concentrations of EPA and DHA were higher in the D group, although AA concentrations were lower (P ≤ 0.05). In part 2, CHF was produced by subcutaneous injection of monocrotaline into 5-wk-old rats. At 3 d before monocrotaline injection, rats were administered either saline, EPA-Et, or DHA-Et as mentioned above and then killed at 21 d. The study groups were as follows: normal + saline (control), CHF + saline (H group), CHF + EPA-Et (HE group), and CHF + DHA-Et (HD group). QT intervals were significantly shorter (P ≤ 0.05) in the control and HD groups compared with the H and HE groups. Relative to the H group, concentrations of EPA were higher in the HE group and those of DHA were higher in the control and HD groups (P ≤ 0.05). There was less mononuclear cell infiltration in the myocytes of the HD group than in the H group (P = 0.06). The right ventricles in the H, HE, and HD groups showed significantly increased weights (P ≤ 0.05) compared with controls. The administration of EPA-Et or DHA-Et may affect cardiac function by modification of heart fatty acid composition, and the administration of DHA-Et may ameliorate CHF.

Efficient display of active Geotrichum sp. lipase on Pichia pastoris cell wall and its application as a whole-cell biocatalyst to enrich EPA and DHA in fish oil

Geotrichum sp. lipase (GSL) was first displayed on the cell wall of Pichia pastoris on the basis of the a-agglutinin anchor system developed in Saccharomyces cerevisiae . Surface display levels were monitored using Western blotting, immunofluorescence miscroscopy, and fluorescence-activated cell sorting analysis. Lipase activity of the yeast whole cells reached a maximum at 273 ± 2.4 U/g of dry cells toward olive oil after 96 h of culture at 30 °C, with optimal pH and temperature at 7.5 and 45 °C, respectively. Displayed GSL exhibited relatively high stability between pH 6.0 and 8.0 and retained >70% of the maximum activity. The surface-displayed lipase retained 80% of its original activity after incubation at 45 °C for 4 h. Moreover, the GSL-displaying yeast whole cells were then used as a biocatalyst to enrich eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil on the basis of selective hydrolysis. As a result, EPA and DHA increased from 1.53 and 24.1% in the original fish oil to 1.85 and 30.86%, which were increases of 1.21- and 1.29-fold, respectively. The total yield of EPA and DHA reached 46.62%.

A novel halophilic lipase, LipBL, showing high efficiency in the production of eicosapentaenoic acid (EPA)

Background

Among extremophiles, halophiles are defined as microorganisms adapted to live and thrive in diverse extreme saline environments. These extremophilic microorganisms constitute the source of a number of hydrolases with great biotechnological applications. The interest to use extremozymes from halophiles in industrial applications is their resistance to organic solvents and extreme temperatures. Marinobacter lipolyticus SM19 is a moderately halophilic bacterium, isolated previously from a saline habitat in South Spain, showing lipolytic activity.

Methods and Findings

A lipolytic enzyme from the halophilic bacterium Marinobacter lipolyticus SM19 was isolated. This enzyme, designated LipBL, was expressed in Escherichia coli. LipBL is a protein of 404 amino acids with a molecular mass of 45.3 kDa and high identity to class C β-lactamases. LipBL was purified and biochemically characterized. The temperature for its maximal activity was 80°C and the pH optimum determined at 25°C was 7.0, showing optimal activity without sodium chloride, while maintaining 20% activity in a wide range of NaCl concentrations. This enzyme exhibited high activity against short-medium length acyl chain substrates, although it also hydrolyzes olive oil and fish oil. The fish oil hydrolysis using LipBL results in an enrichment of free eicosapentaenoic acid (EPA), but not docosahexaenoic acid (DHA), relative to its levels present in fish oil. For improving the stability and to be used in industrial processes LipBL was immobilized in different supports. The immobilized derivatives CNBr-activated Sepharose were highly selective towards the release of EPA versus DHA. The enzyme is also active towards different chiral and prochiral esters. Exposure of LipBL to buffer-solvent mixtures showed that the enzyme had remarkable activity and stability in all organic solvents tested.

Conclusions

In this study we isolated, purified, biochemically characterized and immobilized a lipolytic enzyme from a halophilic bacterium M. lipolyticus, which constitutes an enzyme with excellent properties to be used in the food industry, in the enrichment in omega-3 PUFAs.

Enzymatic enrichment of polyunsaturated fatty acids using novel lipase preparations modified by combination of immobilization and fish oil treatment

Novel modification methods for lipase biocatalysts effective in hydrolysis of fish oil for enrichment of polyunsaturated fatty acids (PUFAs) were described. Based on conventional immobilization in single aqueous medium, immobilization of lipase in two phase medium composed of buffer and octane was employed. Furthermore, immobilization (in single aqueous or in two phase medium) coupled to fish oil treatment was integrated. Among these, lipase immobilized in two phase medium coupled to fish oil treatment (IMLAOF) had advantages over other modified lipases in initial reaction rate and hydrolysis degree. The hydrolysis degree increased from 12% with the free lipase to 40% with IMLAOF. Strong polar and hydrophobic solvents had negative impact on immobilization-fish oil treatment lipases, while low polar solvents were helpful to maintain the modification effect of immobilization-fish oil treatment. After five cycles of usage, the immobilization-fish oil treatment lipases still maintained more than 80% of relative hydrolysis degree.

Microbial production of docosahexaenoic acid by a low temperature-adaptive strain Thraustochytriidae sp. Z105: screening and optimization

As an alternative source in addition to fish oil, microbial production of docosahexaenoic acid has been recieved more and more attentions owing to their culture advantage. A unicellular eukaryotic microbe with high DHA production and capable of low temperature-adaptive growth was isolated from seawater and identified as Thraustochytriidae sp. Z105. The siginificant effect of temperature on cell growth and DHA synthesis by the strain was revealed. It could grow and produce DHA even at 4 degrees C, but hardly grow above 35 degrees C. Low temperature (15-25 degrees C) was favorable for formation of biomass, lipids and DHA, but DHA synthesis was completely blocked above 30 degrees C. Conditions for high level DHA production by Thraustochytriidae sp. Z105 in flask culture were optimized as follows: medium containing glucose 80 g/l, yeast extract 5.0 g/l, K2HPO(4) . 3 H2O 1.0 g/l, MgSO4 . 7 H2O 0.5 g/l, seawater crystal 20 g/l, pH 6.0, liquid volume 30 ml/250 ml, temperature 20 degrees C, agitation speed of 200 r/min, and culture for 120 h. Under the optimal conditions, biomass of 16.72 g/l, total lipids of 5.35 g/l, DHA yield of 1.71 g/l (accounting for 32% of the total lipids) were achieved, respectively. In flask cluture level, the DHA productivity of Thraustochytriidae sp. Z105 was higher than most reported results, which suggested the wild type strain was a potential superior candidate for industrialization of DHA production. Moreover, the strain is an unique and valuable resource for investigation of the low temperature adaptive mechanism related to DHA synthesis.