Marine-Derived Lipases for Enhancing Enrichment of Very-Long-Chain Polyunsaturated Fatty Acids with Reference to Omega-3 Fatty Acids.

Omega-3 fatty acids are essential fatty acids that are not synthesised by the human body and have been linked with the prevention of chronic illnesses such as cardiovascular and neurodegenerative diseases. However, the current dietary habits of the majority of the population include lower omega-3 content compared to omega-6, which does not promote good health. To overcome this, pharmaceutical and nutraceutical companies aim to produce omega-3-fortified foods. For this purpose, various approaches have been employed to obtain omega-3 concentrates from sources such as fish and algal oil with higher amounts of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Among these techniques, enzymatic enrichment using lipase enzymes has gained tremendous interest as it is low in capital cost and simple in operation. Microorganism-derived lipases are preferred as they are easily produced due to their higher growth rate, and they hold the ability to be manipulated using genetic modification. This review aims to highlight the recent studies that have been carried out using marine lipases for the enrichment of omega-3, to provide insight into future directions. Overall, the covalent bond-based lipase immobilization to various support materials appears most promising; however, greener and less expensive options need to be strengthened.

Production of Alginate Oligosaccharides (AOSs) Using Enhanced Physicochemical Properties of Immobilized Alginate Lyase for Industrial Application.

Alginate lyase (AL) is a polysaccharide-degrading enzyme that can degrade alginate by hydrolyzing glycosidic bonds and produces unsaturated alginate oligosaccharides (AOSs). These AOSs have wide therapeutic and nutraceutical applications. However, to produce alginate oligosaccharides in a cost-effective manner is challenging due to the low availability and high cost of this degrading enzyme. Immobilization of the enzyme facilitates industrial applications owing to its stability, reusability, and cost-effectiveness. This study was focused on the enhancement of the properties of alginate lyase and improvement of the production of AOS. Alginate lyase was immobilized on magnetic nanoparticles (NPs) using glutaraldehyde as the crosslinker. The study showed that the maximum binding achieved between NPs and protein in the enzyme was 71% at a ratio of 1:150 NP:protein. As a result of immobilization, the optimum activity of free enzyme which was obtained at 37 °C and pH 7.4 changed to 45 °C and pH 9. Furthermore, the enzyme was thermostable at 45 °C for 3 h with up to 50% reusability for six consecutive cycles. Storage stability after 15 days showed ~67% relative hydrolysis of alginate. The free alginate lyase (25 IU) showed 76% raw biomass (seaweed) hydrolysis which is higher compared to 63% provided by the immobilized enzyme. As a result of efficient hydrolysis, AOSs with molecular weight profile of 370-1040 kDa were produced and detected using HPLC.

Oleaginous Microbial Lipids' Potential in the Prevention and Treatment of Neurological Disorders.

The products of oleaginous microbes, primarily lipids, have gained tremendous attention for their health benefits in food-based applications as supplements. However, this emerging biotechnology also offers a neuroprotective treatment/management potential for various diseases that are seldom discussed. Essential fatty acids, such as DHA, are known to make up the majority of brain phospholipid membranes and are integral to cognitive function, which forms an important defense against Alzheimer's disease. Omega-3 polyunsaturated fatty acids have also been shown to reduce recurrent epilepsy seizures and have been used in brain cancer therapies. The ratio of omega-3 to omega-6 PUFAs is essential in maintaining physiological function. Furthermore, lipids have also been employed as an effective vehicle to deliver drugs for the treatment of diseases. Lipid nanoparticle technology, used in pharmaceuticals and cosmeceuticals, has recently emerged as a biocompatible, biodegradable, low-toxicity, and high-stability means for drug delivery to address the drawbacks associated with traditional medicine delivery methods. This review aims to highlight the dual benefit that lipids offer in maintaining good health for disease prevention and in the treatment of neurological diseases.

Integration of the Exogenous Tuning of Thraustochytrid Fermentation and Sulfur Polymerization of Single-Cell Oil for Developing Plant-like Oils.

In this study, we have demonstrated a bioprocessing approach encompassing the exogenous addition of low-molecular-weight compounds to tune the fatty acid (FA) profile in a novel thraustochytrid strain to produce desirable FAs. Maximum lipid recovery (38%, dry wt. biomass) was obtained at 1% Tween 80 and 0.25 mg/L of Vitamin B12. The transesterified lipid showed palmitic acid (C16, 35.7% TFA), stearic acid (C18, 2.1% TFA), and oleic acid (C18:1, 18.7% TFA) as the main components of total FAs, which are mainly present in plant oils. Strikingly, D-limonene addition in the fermentation medium repressed the production of polyunsaturated fatty acid (PUFAs). Sulfur-polymerization-guided lipid separation revealed the presence of saturated (SFAs, 53% TFA) and monounsaturated fatty acids (MUFAs, 46.6% TFA) in thraustochytrid oil that mimics plant-oil-like FA profiles. This work is industrially valuable and advocates the use of sulfur polymerization for preparation of plant-like oils through tuneable thraustochytrid lipids.

Purification and Characterization of a Novel Alginate Lyase from a Marine Streptomyces Species Isolated from Seaweed.

Alginate, a natural polysaccharide derived from brown seaweed, is finding multiple applications in biomedicine via its transformation through chemical, physical, and, increasingly, enzymatic processes. In this study a novel alginate lyase, AlyDS44, was purified and characterized from a marine actinobacterium, Streptomyces luridiscabiei, which was isolated from decomposing seaweed. The purified enzyme had a specific activity of 108.6 U/mg, with a molecular weight of 28.6 kDa, and was composed of 260 amino acid residues. AlyDS44 is a bifunctional alginate lyase, active on both polyguluronate and polymannuronate, though it preferentially degrades polyguluronate. The optimal pH of this enzyme is 8.5 and the optimal temperature is 45 °C. It is a salt-tolerant alginate lyase with an optimal activity at 0.6 M NaCl. Metal ions Mn2+, Co2+, and Fe2+ increased the alginate degrading activity, but it was inhibited in the presence of Zn2+ and Cu2+. The highly conserved regions of its amino acid sequences indicated that AlyDS44 belongs to the polysaccharide lyase family 7. The main breakdown products of the enzyme on alginate were disaccharides, trisaccharides, and tetrasaccharides, which demonstrated that this enzyme acted as an endo-type alginate lyase. AlyDS44 is a novel enzyme, with the potential for efficient production of alginate oligosaccharides with low degrees of polymerization.

The Nutritional and Pharmacological Potential of New Australian Thraustochytrids Isolated from Mangrove Sediments.

Mangrove sediments represent unique microbial ecosystems that act as a buffer zone, biogeochemically recycling marine waste into nutrient-rich depositions for marine and terrestrial species. Marine unicellular protists, thraustochytrids, colonizing mangrove sediments have received attention due to their ability to produce large amounts of long-chain ω3-polyunsaturated fatty acids. This paper represents a comprehensive study of two new thraustochytrids for their production of valuable biomolecules in biomass, de-oiled cakes, supernatants, extracellular polysaccharide matrixes, and recovered oil bodies. Extracted lipids (up to 40% of DW) rich in polyunsaturated fatty acids (up to 80% of total fatty acids) were mainly represented by docosahexaenoic acid (75% of polyunsaturated fatty acids). Cells also showed accumulation of squalene (up to 13 mg/g DW) and carotenoids (up to 72 µg/g DW represented by astaxanthin, canthaxanthin, echinenone, and ß-carotene). Both strains showed a high concentration of protein in biomass (29% DW) and supernatants (2.7 g/L) as part of extracellular polysaccharide matrixes. Alkalinization of collected biomass represents a new and easy way to recover lipid-rich oil bodies in the form of an aqueous emulsion. The ability to produce added-value molecules makes thraustochytrids an important alternative to microalgae and plants dominating in the food, pharmacological, nutraceutical, and cosmetics industries.

Bioethanol production by a xylan fermenting thermophilic isolate Clostridium strain DBT-IOC-DC21.

To overcome the challenges associated with combined bioprocessing of lignocellulosic biomass to biofuel, finding good organisms is essential. An ethanol producing bacteria DBT-IOC-DC21 was isolated from a compost site via preliminary enrichment culture on a pure hemicellulosic substrate and identified as a Clostridium strain by 16S rRNA analysis. This strain presented broad substrate spectrum with ethanol, acetate, lactate, and hydrogen as the primary metabolic end products. The optimum conditions for ethanol production were found to be an initial pH of 7.0, a temperature of 70 °C and an L-G ratio of 0.67. Strain presented preferential hemicellulose fermentation when compared to various substrates and maximum ethanol concentration of 26.61 mM and 43.63 mM was produced from xylan and xylose, respectively. During the fermentation of varying concentration of xylan, a substantial amount of ethanol ranging from 25.27 mM to 67.29 mM was produced. An increased ethanol concentration of 40.22 mM was produced from a mixture of cellulose and xylan, with a significant effect observed on metabolic flux distribution. The optimum conditions were used to produce ethanol from 28 g L-1 rice straw biomass (RSB) (equivalent to 5.7 g L-1 of the xylose equivalents) in which 19.48 mM ethanol production was achieved. Thus, Clostridium strain DBT-IOC-DC21 has the potential to perform direct microbial conversion of untreated RSB to ethanol at a yield comparative to xylan fermentation.

Balsamin induces apoptosis in breast cancer cells via DNA fragmentation and cell cycle arrest.

Breast cancer is the second most common cancer causing death worldwide with metastasis and disease relapse being the major drawbacks in current treatments. Therefore, development of novel drugs is needed. Balsamin, a 28 kDa Type I ribosome-inactivating protein, is rich in the seeds of Momordica balsamina. In this study, the molecular mechanism and the possible effects of balsamin on the two key hallmarks of cancer were investigated. Firstly, the induction of apoptosis in human breast cancer MCF-7 and BT549 cells showed that balsamin-induced apoptosis involved increases in caspase-3 and caspase-8 activity, upregulation of Bax, Bid, and Bad, and downregulation of BCL-2 and BCL-XL. Furthermore, balsamin inhibited the proliferation of breast cancer cells in a dose-dependent manner with IC50 values of 24.53 and 32.79 µg/ml for MCF-7 and BT549 cells, respectively. Moreover, flow cytometric analysis revealed that balsamin induced S-/G-phase cell cycle arrest. Our studies show that balsamin has anti-tumor activity and could be used as a neutraceutical for the treatment of breast cancer.

Biotechnological applications of microbial bioconversions.

Modern research has focused on the microbial transformation of a huge variety of organic compounds to obtain compounds of therapeutic and/or industrial interest. Microbial transformation is a useful tool for producing new compounds, as a consequence of the variety of reactions for natural products. This article describes the production of many important compounds by biotransformation. Emphasis is placed on reporting the metabolites that may be of special interest to the pharmaceutical and biotechnological industries, as well as the practical aspects of this work in the field of microbial transformations.

Recent trends in nanomaterials immobilised enzymes for biofuel production.

Application of nanomaterials as novel supporting materials for enzyme immobilisation has generated incredible interest in the biotechnology community. These robust nanostructured forms, such as nanoparticles, nanofibres, nanotubes, nanoporous, nanosheets, and nanocomposites, possess a high surface area to volume ratios that can cause a high enzyme loading and facilitate reaction kinetics, thus improving biocatalytic efficiency for industrial applications. In this article, we discuss research opportunities of nanoscale materials in enzyme biotechnology and highlight recent developments in biofuel production using advanced material supports for enzyme immobilisation and stabilisation. Synthesis and functionalisation of nanomaterial forms using different methods are highlighted. Various simple and effective strategies designed to result in a stable, as well as functional protein-nanomaterial conjugates are also discussed. Analytical techniques confirming enzyme loading on nanomaterials and assessing post-immobilisation changes are discussed. The current status of versatile nanomaterial support for biofuel production employing cellulases and lipases is described in details. This report concludes with a discussion on the likely outcome that nanomaterials will become an integral part of sustainable bioenergy production.

Isolation and polyphasic characterization of a novel hyper catalase producing thermophilic bacterium for the degradation of hydrogen peroxide.

A newly isolated microbial strain of thermophilic genus Geobacillus has been described with emphasis on polyphasic characterization and its application for degradation of hydrogen peroxide. The validation of this thermophilic strain of genus Geobacillus designated as BSS-7 has been demonstrated by polyphasic taxonomy approaches through its morphological, biochemical, fatty acid methyl ester profile and 16S rDNA sequencing. This thermophilic species of Geobacillus exhibited growth at broad pH and temperature ranges coupled with production of extraordinarily high quantities of intracellular catalase, the latter of which as yet not been reported in any member of this genus. The isolated thermophilic bacterial culture BSS-7 exhibited resistance against a variety of organic solvents. The immobilized whole cells of the bacterium successfully demonstrated the degradation of hydrogen peroxide (H2O2) in a packed bed reactor. This strain has potential application in various analytical and diagnostic methods in the form of biosensors and biomarkers in addition to applications in the textile, paper, food and pharmaceutical industries.

Functional Analysis of a Type-I Ribosome Inactivating Protein Balsamin from Momordica balsamina with Anti-Microbial and DNase Activity.

Ribosome inactivating proteins (RIPs) have received considerable attention in biomedical research because of their unique activities towards tumor and virus-infected cells. We extracted balsamin, a type-I RIP, from Momordica balsamina. In the present study, a detailed investigation on DNase activity, antioxidant capacity and antibacterial activity was conducted using purified balsamin. DNase-like activity of balsamin towards plasmid DNA was pH, incubation time and temperature dependent. Moreover, the presence of Mg(2+) (10-50 mM) influenced the DNA cleavage activity. Balsamin also demonstrated reducing power and a capacity to scavenge free radicals in a dose dependent manner. Furthermore, the protein exhibited antibacterial activity against Staphylococcus aureus, Salmonella enterica, Staphylococcus epidermidis and Escherichia coli, which suggests potential utility of balsamin as a nutraceutical.

Comparison of Cell Disruption Methods for Improving Lipid Extraction from Thraustochytrid Strains.

Lipid extraction is an integral part of biodiesel production, as it facilitates the release of fatty acids from algal cells. To utilise thraustochytrids as a potential source for lipid production. We evaluated the extraction efficiency of various solvents and solvent combinations for lipid extraction from Schizochytrium sp. S31 and Thraustochytrium sp. AMCQS5-5. The maximum lipid extraction yield was 22% using a chloroform:methanol ratio of 2:1. We compared various cell disruption methods to improve lipid extraction yields, including grinding with liquid nitrogen, bead vortexing, osmotic shock, water bath, sonication and shake mill. The highest lipid extraction yields were obtained using osmotic shock and 48.7% from Schizochytrium sp. S31 and 29.1% from Thraustochytrium sp. AMCQS5-5. Saturated and monounsaturated fatty acid contents were more than 60% in Schizochytrium sp. S31 which suggests their suitability for biodiesel production.

Addition of magnesium chloride to enhance mono-dispersity of a coiled-coil recombinant mouse macrophage protein.

X-ray crystallography for the determination of three-dimensional structures of protein macromolecules represents an important tool in function assignment of uncharacterized proteins. However, crystallisation is often difficult to achieve. A protein sample fully characterized in terms of dispersity may increase the likelihood of successful crystallisation by improving the predictability of the crystallisation process. To maximize the probability of crystallisation of a novel mouse macrophage protein (rMMP), target molecule was characterized and refined to improve monodispersity. Addition of MgCl2 at low concentrations resolves the rMMP into a monodisperse solution, and finally successful crystallization of rMMP was achieved. The effect of MgCl2 was studied using gel filtration chromatography and dynamic light scattering.

Therapeutic TNF Inhibitors Exhibit Differential Levels of Efficacy in Accelerating Cutaneous Wound Healing.

Adalimumab but neither etanercept nor certolizumab-pegol has been reported to induce a wound-healing profile in vitro by regulating macrophage differentiation and matrix metalloproteinase expression, which may underlie the differences in efficacy between various TNF-α inhibitors in impaired wound healing in patients with hidradenitis suppurativa, a chronic inflammatory skin disease. To examine and compare the efficacy of various TNF inhibitors in cutaneous wound healing in vivo, a human TNF knock-in Leprdb/db mouse model was established to model the impaired cutaneous wound healing as seen in hidradenitis suppurativa. The vehicle group exhibited severe impairments in cutaneous wound healing. In contrast, adalimumab significantly accelerated healing, confirmed by both histologic assessment and a unique healing transcriptional profile. Moreover, adalimumab and infliximab showed similar levels of efficacy, but golimumab was less effective, along with etanercept and certolizumab-pegol. In line with histologic assessments, proteomics analyses from healing wounds exposed to various TNF inhibitors revealed distinct and differential wound-healing signatures that may underlie the differential efficacy of these inhibitors in accelerating cutaneous wound healing. Taken together, these data revealed that TNF inhibitors exhibited differential levels of efficacy in accelerating cutaneous wound healing in the impaired wound-healing model in vivo.

FTIR microspectroscopy for rapid screening and monitoring of polyunsaturated fatty acid production in commercially valuable marine yeasts and protists.

The increase in polyunsaturated fatty acid (PUFA) consumption has prompted research into alternative resources other than fish oil. In this study, a new approach based on focal-plane-array Fourier transform infrared (FPA-FTIR) microspectroscopy and multivariate data analysis was developed for the characterisation of some marine microorganisms. Cell and lipid compositions in lipid-rich marine yeasts collected from the Australian coast were characterised in comparison to a commercially available PUFA-producing marine fungoid protist, thraustochytrid. Multivariate classification methods provided good discriminative accuracy evidenced from (i) separation of the yeasts from thraustochytrids and distinct spectral clusters among the yeasts that conformed well to their biological identities, and (ii) correct classification of yeasts from a totally independent set using cross-validation testing. The findings further indicated additional capability of the developed FPA-FTIR methodology, when combined with partial least squares regression (PLSR) analysis, for rapid monitoring of lipid production in one of the yeasts during the growth period, which was achieved at a high accuracy compared to the results obtained from the traditional lipid analysis based on gas chromatography. The developed FTIR-based approach when coupled to programmable withdrawal devices and a cytocentrifugation module would have strong potential as a novel online monitoring technology suited for bioprocessing applications and large-scale production.

Nanobiotechnology as a novel paradigm for enzyme immobilisation and stabilisation with potential applications in biodiesel production.

Nanobiotechnology is emerging as a new frontier of biotechnology. The potential applications of nanobiotechnology in bioenergy and biosensors have encouraged researchers in recent years to investigate new novel nanoscaffolds to build robust nanobiocatalytic systems. Enzymes, mainly hydrolytic class of enzyme, have been extensively immobilised on nanoscaffold support for long-term stabilisation by enhancing thermal, operational and storage catalytic potential. In the present report, novel nanoscaffold variants employed in the recent past for enzyme immobilisation, namely nanoparticles, nanofibres, nanotubes, nanopores, nanosheets and nanocomposites, are discussed in the context of lipase-mediated nanobiocatalysis. These nanocarriers have an inherently large surface area that leads to high enzyme loading and consequently high volumetric enzyme activity. Due to their high tensile strengths, nanoscale materials are often robust and resistant to breakage through mechanical shear in the running reactor making them suitable for multiple reuses. The optimisation of various nanosupports process parameters, such as the enzyme type and selection of suitable immobilisation method may help lead to the development of an efficient enzyme reactor. This might in turn offer a potential platform for exploring other enzymes for the development of stable nanobiocatalytic systems, which could help to address global environmental issues by facilitating the production of green energy. The successful validation of the feasibility of nanobiocatalysis for biodiesel production represents the beginning of a new field of research. The economic hurdles inherent in viably scaling nanobiocatalysts from a lab-scale to industrial biodiesel production are also discussed.

Pollen baiting facilitates the isolation of marine thraustochytrids with potential in omega-3 and biodiesel production.

Marine heterotrophic microbes are capable of accumulating large amounts of lipids, omega-3 fatty acids, carotenoids, and have potential for biodiesel production. Pollen baiting using Pinus radiata pollen grain along with direct plating techniques were used in this study as techniques for the isolation of oil-producing marine thraustochytrid species from Queenscliff, Victoria, Australia. Thirteen isolates were obtained using either direct plating or using pine pollen, with pine pollen acting as a specific substrate for the surface attachment of thraustochytrids. The isolates obtained from the pollen baiting technique showed a wide range of docosahexaenoic acid (DHA) accumulation, from 11 to 41 % of total fatty acid content (TFA). Direct plating isolates showed a moderate range of DHA accumulation, from 19 to 25 % of TFA. Seven isolates were identified on the basis of 18S rRNA sequencing technique as Thraustochytrium species, Schizochytrium species, and Ulkenia species. Although both methods appear to result in the isolation of similar strains, pollen baiting proved to be a simpler method for the isolation of these relatively slow-growing organisms.

Repurposing mucosal delivery devices for live attenuated tuberculosis vaccines.

Tuberculosis (TB) remains one of the most lethal infectious diseases globally. The only TB vaccine approved by the World Health Organization, Bacille Calmette-Guérin (BCG), protects children against severe and disseminated TB but provides limited protection against pulmonary TB in adults. Although several vaccine candidates have been developed to prevent TB and are undergoing preclinical and clinical testing, BCG remains the gold standard. Currently, BCG is administered as an intradermal injection, particularly in TB endemic countries. However, mounting evidence from experimental animal and human studies indicates that delivering BCG directly into the lungs provides enhanced immune responses and greater protection against TB. Inhalation therapy using handheld delivery devices is used for some diseases and allows the delivery of drugs or vaccines directly into the human respiratory tract. Whether this mode of delivery could also be applicable for live attenuated bacterial vaccines such as BCG or other TB vaccine candidates remains unknown. Here we discuss how two existing inhalation devices, the mucosal atomization device (MAD) syringe, used for influenza vaccines, and the Respimat® Soft Mist™ inhaler, used for chronic obstructive pulmonary disease (COPD) therapy, could be repurposed for mucosal delivery of live attenuated TB vaccines. We also outline the challenges and outstanding research questions that will require further investigations to ensure usefulness of respiratory delivery devices that are cost-effective and accessible to lower- and middle-income TB endemic countries.

Development of sustainable downstream processing for nutritional oil production.

Nutritional oils (mainly omega-3 fatty acids) are receiving increased attention as critical supplementary compounds for the improvement and maintenance of human health and wellbeing. However, the predominant sources of these oils have historically shown numerous limitations relating to desirability and sustainability; hence the crucial focus is now on developing smarter, greener, and more environmentally favourable alternatives. This study was undertaken to consider and assess the numerous prevailing and emerging techniques implicated across the stages of fatty acid downstream processing. A structured and critical comparison of the major classes of disruption methodology (physical, chemical, thermal, and biological) is presented, with discussion and consideration of the viability of new extraction techniques. Owing to a greater desire for sustainable industrial practices, and a desperate need to make nutritional oils more available; great emphasis has been placed on the discovery and adoption of highly sought-after 'green' alternatives, which demonstrate improved efficiency and reduced toxicity compared to conventional practices. Based on these findings, this review also advocates new forays into application of novel nanomaterials in fatty acid separation to improve the sustainability of nutritional oil downstream processing. In summary, this review provides a detailed overview of the current and developing landscape of nutritional oil; and concludes that adoption and refinement of these sustainable alternatives could promptly allow for development of a more complete 'green' process for nutritional oil extraction; allowing us to better meet worldwide needs without costing the environment.