Effect of Anaerobic Digestate on the Fatty Acid Profile and Biodiesel Properties of Chlorella sorokiniana Grown Heterotrophically

The growth kinetics and the lipid and protein content of the microalgal species Chlorella sorokiniana (CS) grown heterotrophically in growth media containing glycerol and increasing amounts of anaerobic digestate (AD) equal to 0%, 15%, 30%, and 50% was studied. The effect of the AD on the fatty acid (FA) distribution of the bio-oil extracted from the CS, as well as on the fatty acid methyl ester (FAME) properties such as the saponification number (SN), the iodine value (IV), the cetane number (CN), and the higher heating value (HHV) was also estimated. The percentage of AD in the growth medium affects the rate of carbon uptake. The maximum carbon uptake rate occurs at about 30% AD. Protein and lipid content ranged from 32.3–38.4% and 18.1–23.1%, respectively. Fatty acid distribution ranged from C10 to C26. In all AD percentages the predominant fatty acids were the medium chain FA C16 to C18 constituting up to about 89% of the total FA at 0% AD and 15% AD and up to about 54% of the total FA at 30% AD and 50% AD. With respect to unsaturation, monounsaturated FA (MUFA) were predominant, up to 56%, while significant percentages, up to about 38%, of saturated FA (SFA) were also produced. The SN, IV, CN, and HHV ranged from 198.5–208.3 mg KOH/g FA, 74.5–93.1 g I/100 g FAME, 52.7–56.1, and 39.7–40.0 MJ/kg, respectively. The results showed that with increasing AD percentage, the CN values tend to increase, while decrease in IV leads to biofuel with better ignition quality.

Sustained Wellbeing Benefits of Red Meat Consumption in a Modern Flexitarian Diet: A Study Protocol for a 10 Week Randomised Clinical Trial (Preprint)

UNSTRUCTURED Background The trend of flexitarian eating patterns is on the rise, with young adults amongst the biggest adopters claiming health and environmental reasons to reduce red meat intake. Nutrient dense meat and animal products are often the lynchpin of these diets, even when consumed only occasionally and in moderate amounts. Red meat provides forms and concentrations of essential proteins, lipids, and micronutrients that are scarce in exclusively vegetarian regimens. Objective The aim of this investigation is to consider the effects of moderate consumption of lean red meat as part of an otherwise vegetarian balanced diet and its impact on biomarkers of sustained health and wellbeing. Methods A cohort of healthy, young (20-34 years) male and female participants will take part in two-arm parallel, randomised-controlled trial for a duration of 12 weeks, with a 3-month post follow-up. The trial will commence with a two-week assessment period followed by allocation to the intervention arms. The intervention will include the consumption of red meat or meat-alternatives three times per week for 10 weeks. Blood samples of the participants will be measured for changes in erythrocyte fatty acid distribution, circulating amino acids, neurotransmitters, markers of mineral status and inflammatory markers. Questionnaires to assess wellbeing and mental health will be undertaken every two weeks. Body composition, physical function test, blood measurements will be assessed at allocation (t0), week five into the intervention (t5) and post intervention (t10). Discussion To our knowledge this is the first randomised controlled trial (RCT) investigating the overarching health consequences of consuming NZ pasture fed red meat or no meat, as part of a healthy diet.

Hepatic lipid signatures of little brown bats (Myotis lucifugus) and big brown bats (Eptesicus fuscus) at early stages of white-nose syndrome

White-nose syndrome (WNS) is an emergent wildlife fungal disease of cave-dwelling, hibernating bats that has led to unprecedented mortalities throughout North America. A primary factor in WNS-associated bat mortality includes increased arousals from torpor and premature fat depletion during winter months. Details of species and sex-specific changes in lipid metabolism during WNS are poorly understood and may play an important role in the pathophysiology of the disease. Given the likely role of fat metabolism in WNS and the fact that the liver plays a crucial role in fatty acid distribution and lipid storage, we assessed hepatic lipid signatures of little brown bats (Myotis lucifugus) and big brown bats (Eptesicus fuscus) at an early stage of infection with the etiological agent, Pseudogymnoascus destructans (Pd). Differences in lipid profiles were detected at the species and sex level in the sham-inoculated treatment, most strikingly in higher hepatic triacylglyceride (TG) levels in E. fuscus females compared to males. Interestingly, several dominant TGs (storage lipids) decreased dramatically after Pd infection in both female M. lucifugus and E. fuscus. Increases in hepatic glycerophospholipid (structural lipid) levels were only observed in M. lucifugus, including two phosphatidylcholines (PC [32:1], PC [42:6]) and one phosphatidylglycerol (PG [34:1]). These results suggest that even at early stages of WNS, changes in hepatic lipid mobilization may occur and be species and sex specific. As pre-hibernation lipid reserves may aid in bat persistence and survival during WNS, these early perturbations to lipid metabolism could have important implications for management responses that aid in pre-hibernation fat storage.

Comparative Fatty Acid Profiling of Klebsiella pneumoniae and Rhodococcus rhodochrous Isolated from Spoilt Paints by Gas Chromatography

The use of fatty acids to study the differences in un-related microbes is limited. This study analyzes the fatty acids produced by two unrelated microorganisms: Klebsiella pneumoniae (Gram-negative, aerobic, non-endospore forming, usually encapsulated rod-shaped bacteria of the family Enterobacteriaceae) and Rhodococcus rhodochrous (metabolically versatile, non-spore-forming, non-motile actinomycete) isolated from spoilt paints. Fatty acids produced by the organisms were analyzed using an efficient MIDI-Sherlock gas chromatography method . K. pneumoniae was characterized by a high content of straight chain, branched chain, hydroxyl and cyclo-fatty acids made up of C12: 0, C13:0, C14:0 iso, C14:0, C15:0 iso, C15:0 anteiso, C15:1 ω 8c, C15:0, C16:0 iso, C16:1w5c, C16:0, C15:03OH, C17:1 ω 8c, C17:0 cyclo, C17:0, C18:1 ω5c and C18:0. R. rhodochrous was dominated by straight chain, monounsaturated and 10-methyl fatty acids. The inability to synthesize branched, cyclo- and hydroxyl- fatty acids, was observed in R. rhodochrous which composed mainly of C14: 0, C15: 1 ω 5c, C15:0, C16:1 ω 9c, C16:0, C17:1 ω 8c, C17:0, C17:0 10-methyl, C18: 1 ω 9c, C18.0, 10 methyl-C18:0 TBSA, C20:1 ω 9c, and C20:0. Descriptive statistics reveal a mean of 2.53, 15.10 and 15.15 for retention time (RT), equivalent chain length (ECL) and Peak name, respectively. Possible implications of the variations in fatty acid distribution may include differences in their abilities to produce various secondary metabolites and potentials to degrade a variety of xenobiotics. Keywords: Fatty acids, paints, Rhodococcus rhodochrous, Klebsiella pneumoniae

Biorefinery-Based Approach to Exploit Mixed Cultures of Lipomyces starkeyi and Chloroidium saccharophilum for Single Cell Oil Production

The mutualistic interactions between the oleaginous yeast Lipomyces starkeyi and the green microalga Chloroidium saccharophilum in mixed cultures were investigated to exploit possible synergistic effects. In fact, microalga could act as an oxygen generator for the yeast, while the yeast could provide carbon dioxide to microalga. The behavior of the two microorganisms alone and in mixed culture was studied in two synthetic media (YEG and BBM + G) before moving on to a real model represented by the hydrolysate of Arundo donax, used as low-cost feedstock, and previously subjected to steam explosion and enzymatic hydrolysis. The overall lipid content and lipid productivity obtained in the mixed culture of YEG, BBM + G and for the hydrolysate of Arundo donax were equal to 0.064, 0.064 and 0.081 glipid·gbiomass−1 and 30.14, 35.56 and 37.22 mglipid·L−1·day−1, respectively. The mixed cultures, in all cases, proved to be the most performing compared to the individual ones. In addition, this study provided new input for the integration of Single Cell Oil (SCO) production with agro-industrial feedstock, and the fatty acid distribution mainly consisting of stearic (C18:0) and oleic acid (C18:1) allows promising applications in biofuels, cosmetics, food additives and other products of industrial interest.

Protein Farnesylation Takes Part in Arabidopsis Seed Development

Protein farnesylation is a post-translational modification regulated by the ERA1 (Enhanced Response to ABA 1) gene encoding the β-subunit of the protein farnesyltransferase in Arabidopsis. The era1 mutants have been described for over two decades and exhibit severe pleiotropic phenotypes, affecting vegetative and flower development. We further investigated the development and quality of era1 seeds. While the era1 ovary contains numerous ovules, the plant produces fewer seeds but larger and heavier, with higher protein contents and a modified fatty acid distribution. Furthermore, era1 pollen grains show lower germination rates and, at flower opening, the pistils are immature and the ovules require one additional day to complete the embryo sac. Hand pollinated flowers confirmed that pollination is a major obstacle to era1 seed phenotypes, and a near wild-type seed morphology was thus restored. Still, era1 seeds conserved peculiar storage protein contents and altered fatty acid distributions. The multiplicity of era1 phenotypes reflects the diversity of proteins targeted by the farnesyltransferase. Our work highlights the involvement of protein farnesylation in seed development and in the control of traits of agronomic interest.

Biorefinery-Based Approach to Exploit Mixed Cultures of Lipomyces Starkeyi and Chloroidium saccharophilum for Single Cell Oil Production

The mutualistic interactions between the oleaginous yeast Lipomyces starkeyi and the green mi-croalga Chloroidium saccharophilum in mixed cultures were investigated to exploit possible syner-gistic effects. As a matter of facts, microalga could act as an oxygen generator for the yeast, while the yeast could provide carbon dioxide to microalga. A lignocellulosic hydrolysate from steam exploded Arundo donax (Giant reed) was used as low cost feedstock. The overall lipid content and lipid productivity obtained in the mixed culture treating the hydrolysate of Arundo donax were equal to 0.081 glipid.gbiomass-1 and 37.2 mglipid.L-1.d-1, respectively. They represented promising re-sults if compared to the model systems where synthetic media were used. This study provided new input for the integration of Single Cell Oil (SCO) production with agro-industrial feedstock and the fatty acid distribution mainly consisting of stearic (C18:0) and oleic acid (C18:1) allows promising applications in biofuels, cosmetics, food additives and other products of industrial interest.

In Vitro and In Vivo Digestibility of Soybean, Fish, and Microalgal Oils, and Their Influences on Fatty Acid Distribution in Tissue Lipid of Mice

The digestion rates of microalgal (docosahexaenoic acid, DHA, 56.8%; palmitic acid, 22.4%), fish (DHA, 10.8%; eicosapentaenoic acid, EPA, 16.2%), and soybean oils (oleic, 21.7%; linoleic acid, 54.6%) were compared by coupling the in vitro multi-step and in vivo apparent digestion models using mice. The in vitro digestion rate estimated based on the released free fatty acids content was remarkably higher in soybean and fish oils than in microalgal oil in 30 min; however, microalgal and fish oils had similar digestion rates at longer digestion. The in vivo digestibility of microalgal oil (91.49%) was lower than those of soybean (96.50%) and fish oils (96.99%). Among the constituent fatty acids of the diet oils, docosapentaenoic acid (DPA) exhibited the highest digestibility, followed by EPA, DHA, palmitoleic, oleic, palmitic, and stearic acid, demonstrating increased digestibility with reduced chain length and increased unsaturation degree of fatty acid. The diet oils affected the deposition of fatty acids in mouse tissues, and DHA concentrations were high in epididymal fat, liver, and brain of mice fed microalgal oil. In the present study, microalgal oil showed lower in vitro and in vivo digestibility, despite adequate DHA incorporation into major mouse organs, such as the brain and liver.