Single cell oil production by oleaginous yeasts grown in synthetic and waste-derived volatile fatty acids

Four yeast isolates from the species—Apiotrichum brassicae, Candida tropicalis, Metschnikowia pulcherrima, and Pichia kudriavzevii—previously selected by their oleaginous character and growth flexibility in different carbon sources, were tested for their capacity to convert volatile fatty acids into lipids, in the form of single cell oils. Growth, lipid yields, volatile fatty acids consumption, and long-chain fatty acid profiles were evaluated in media supplemented with seven different volatile fatty acids (acetic, butyric, propionic, isobutyric, valeric, isovaleric, and caproic), and also in a dark fermentation effluent filtrate. Yeasts A. brassicae and P. kudriavzevii attained lipid productivities of more than 40% (w/w), mainly composed of oleic (>40%), palmitic (20%), and stearic (20%) acids, both in synthetic media and in the waste-derived effluent filtrate. These isolates may be potential candidates for single cell oil production in larger scale applications by using alternative carbon sources, combining economic and environmental benefits.This work was supported by the European project "VOLATILE-Biowaste derived volatile fatty acid platform for biopolymers, bioactive compounds and chemical building blocks" (Call H2020-NMBP-BIO-2016 Grant agreement No. 720777) and by the strategic programme UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) funded by national funds through the FCT I.P., by the ERDF through the COMPETE2020

Ensiling Alfalfa (Medicago sativa L.) and Orchard Grass (Dactylis glomerata L.) Forage Harvested at 08:00 or 14:00, without Wilting or 1 or 2 h Wilting and with or without Use of Bacterial Inoculant

Alfalfa forage is difficult to ensile due to low water-soluble carbohydrate content and high buffering capacity. The objective was to assess at Chapingo, Mexico, during the rainy season effects of combinations of harvest hours (08:00, 14:00), wilting time (0, 1, 2 h) and bacterial inoculants on the quality of silage made of alfalfa and orchard grass forage, made in 200-L containers. The experiment was conducted in three phases with two replicates per phase. Variables measured in freshly cut forage and silages were dry matter content (DM), buffer capacity, pH, and alcohol soluble carbohydrates (ASC). Silos remained sealed during 60 d, and additional variables measured in silage were aerobic stability, NH3 -N and in vitro disappearance of DM. In forage harvested at 14:00 h, DM and ASC contents were higher; pH and buffering capacity were not affected by harvest hour; in silages made of that forage, NH3-N levels were lower, while ASC contents and in vitro disappearance of MS were unaffected by harvest hour. Treatments with inoculants were less aerobic stable for 5 days when made of forage harvested at 08:00 h but more stable when made of forage harvested at 14:00 h. Harvesting at 14:00 h was advantageous as silage presented higher DM and ASC contents

Modified high-throughput Nile red fluorescence assay for the rapid screening of oleaginous yeasts using acetic acid as carbon source

Background: Over the last years oleaginous yeasts have been studied for several energetic, oleochemical, medical and pharmaceutical purposes. However, only a small number of yeasts are known and have been deeply exploited. The search for new isolates with high oleaginous capacity becomes imperative, as well as the use of alternative and ecological carbon sources for yeast growth. Results: In the present study a high-throughput screening comprising 366 distinct yeast isolates was performed by applying an optimised protocol based on two approaches: (I) yeast cultivation on solid medium using acetic acid as carbon source, (II) neutral lipid estimation by fluorimetry using the lipophilic dye Nile red. Conclusions: Results showed that, with the proposed methodology, the oleaginous potential of yeasts with broad taxonomic diversity and variety of growth characteristics was discriminated. Furthermore, this work clearly demonstrated the association of the oleaginous yeast character to the strain level, contrarily to the species-level linkage, as usually stated.This work was supported by the European project “VOLATILE - Biowaste derived volatile fatty acid platform for biopolymers, bioactive compounds and chemical building blocks “(Call H2020-NMBP-BIO-2016 Grant agreement No. 720777) and by the strategic programme UID/BIA/04050/2013 (POCI-01- 0145-FEDER-007569) funded by national funds through the FCT I.P., by the ERDF through the COMPETE2020

Study of the quality of fruits of the Hylocereusundatus (Haw) Britton Rose and Hylocereusmegalanthus(K. Schum ex Vaupel) Ralf Baue (Red and Yellow Pitahaya) during the maturationperiod

In this work, the organoleptic and sensorial characteristics were determined, as well as the maturation pattern of the yellow and red pitahaya fruits grown in Ecuador. Several fruit quality indexes were evaluated for 15 days from the moment of harvest, such as: weight loss, dry matter, total soluble solids, titratable acidity, exocarp coloration and maturity relationship and related damages by attack of biotic agents. The results indicated that in storage conditions with a temperature of 25 ± 1 ° C, the red pitahaya presents a gradual loss of fruit quality up to nine days; after this period serious fungal damage to the fruit that affects its commercial quality begins. The yellow pitahaya has a time of storage that can reach up to 15 days, although the fruit looks externally dehydrated and aged; however internally the fruit maintains its quality for consumption. It presents organosensitive standards of quality and resistance to microbiological agents superior to those of the red pitahaya. Due to the behavior of the fruit in the various variables evaluated in this study, strong evidences are presented that suggest to consider it as a species of non-climacteric respiration

InSAR Meteorology: High-Resolution Geodetic Data Can Increase Atmospheric Predictability

AbstractThe present study assesses the added value of high‐resolution maps of precipitable water vapor, computed from synthetic aperture radar interferograms , in short‐range atmospheric predictability. A large set of images, in different weather conditions, produced by Sentinel‐1A in a very well monitored region near the Appalachian Mountains, are assimilated by the Weather Research and Forecast (WRF) model. Results covering more than 2 years of operation indicate a consistent improvement of the water vapor predictability up to a range comparable with the transit time of the air mass in the synthetic aperture radar interferograms footprint, an overall improvement in the forecast of different precipitation events, and better representation of the spatial distribution of precipitation. This result highlights the significant potential for increasing short‐range atmospheric predictability from improved high‐resolution precipitable water vapor initial data, which can be obtained from new high‐resolution all‐weather microwave sensors

Climate change, in the framework of the constructal law

Here we present a simple and transparent alternative to the complex models of Earth thermal behavior under time-changing conditions. We show the one-to-one relationship between changes in atmospheric properties and time-dependent changes in temperature and its distribution on Earth. The model accounts for convection and radiation, thermal inertia and changes in albedo (ρ) and greenhouse factor (γ). The constructal law is used as the principle that governs the evolution of flow configuration in time, and provides closure for the equations that describe the model. In the first part of the paper, the predictions are tested against the current thermal state of Earth. Next, the model showed that for two time-dependent scenarios, (δρ = 0.002; δγ = 0.011) and (δρ = 0.002; δγ = 0.005) the predicted equatorial and polar temperature increases and the time scales are (Δ<i>T</i><sub>H</sub> = 1.16 K; Δ<i>T</i><sub>L</sub> = 1.11 K; 104 years) and (0.41 K; 0.41 K; 57 years), respectively. In the second part, a continuous model of temperature variation was used to predict the thermal response of the Earth's surface for changes bounded by δρ = δγ and δρ = −δγ. The results show that the global warming amplitudes and time scales are consistent with those obtained for δρ = 0.002 and δγ = 0.005. The poleward heat current reaches its maximum in the vicinity of 35° latitude, accounting for the position of the Ferrel cell between the Hadley and Polar Cells

Wake response to an ocean-feedback mechanism: Madeira Island case study

This discussion focused on the numerical study of a wake episode. The Weather Research and Forecasting model was used in a downscale mode. The current literature focuses the discussion on the adiabatic dynamics of atmospheric wakes. Changes in mountain height and consequently on its relation to the atmospheric inversion layer should explain the shift in wake regimes: from a 'strong-wake' to a 'weak-wake' scenario. Nevertheless, changes in SST variability can also induce similar regime shifts. Increase in evaporation, contributes to increase convection and thus to an uplift of the stratified atmospheric layer, above the critical height, with subsequent internal gravity wave activity.Comment: Under review proces

Lipidomic Profile of Rhodotorula toruloides by GC/MS and Antioxidant Capacity of the Oil by DPPH and TLC-Plate Methods

This work was undertaken to evaluate the antioxidant capacity of Rhodotorula toruloides lipid extract in TLC plate, using the (DPPH) (1,1-diphenyl-2-picril-  hydrazine) method as an innovative way to visualise lipid groups that comprise this activity. Similarly, carotenoids and crude oil were analysed for  antioxidant capacity by the DPPH and β-carotene/linoleic acid methods. The lipidomic profile extract analysis was performed by GC/MS and HPLC/DAD.  The sample preparation for the GC/MS analysis was made by ultrasound-assisted transesterification. Free compounds were silylated with BSTFA (N,O-Bis  (trimethylsilyl) trifluoracetamide) + 1% TMCS (Trimethylchlorosilane). The analysis of the lipid extract showed that in the saponifiable fraction saturated  fatty acids (SFA) and monounsaturated fatty acids (MUFA) were present; and in the unsaponifiable fraction were steroids and carotenoids. The antioxidant  capacity was expressed as IC50 reaching 6.4 mg/L that means relative efficiency. The oil profile, using TLC, shows the chemical groups:  carotenoids, acylglycerols, free fatty acids and steroids. Similarly, the GC/ MS analysis shows the fatty acids and steroids. The HPLC analysis describes the  carotenoids profile, highlighting b-carotene as the majority and the presence of β-carotene-5,8-epoxide, zeaxanthin and b-cryptoxanthin, characterising  the lipidomic study of this yeast