Higher biomass accumulation by increasing phosphoribosylpyrophosphate synthetase activity in Arabidopsis thaliana and Nicotiana tabacum

Plants are able to produce all the organic compounds required for development and growth. As developmental processes and metabolic pathways use a common resource pool, the tight regulation of the distribution of metabolites between growth, production of defence compounds and storage products can be assumed. A transgenic approach was used to investigate the importance of supplying the key intermediate phosphoribosylpyrophosphate (PRPP) for plant growth and biomass accumulation in the model plant Arabidopsis thaliana and in Nicotiana tabacum. For this purpose, the Ashbya gossypii genes coding for either PRPP synthetase (PRS) or a mutated variant of the same gene were over-expressed under the control of a constitutive promoter. It was shown that increased PRS activity in A. thaliana or N. tabacum leads to a substantial increase in biomass accumulation under different standardized growth conditions. Growth enhancement was accompanied by significant changes in the amount of sugars and other metabolites. This study provides evidence that the supply of PRPP co-limits growth rates, and has obvious implications for biotechnological strategies aiming to increase plant biomass as an alternative renewable energy source

Absorption of food in the black-jaw tilapia, Sarotherodon melanotheron (Ruppell) from a small tropical man-made lake in Ibadan, Nigeria

The carbohydrate, protein and lipid contents of the food ingested and their absorption in the intestine of Sarotherodon melanotheron inhabiting Awba lake in Ibadan, Nigeria, were investigated. Total carbohydrates of the ingested food ranged from 39.33 to 55.38% (mean = 48.70% while total protein and total lipid ranged from 10.10 to 17.13% (mean = 12.91%) and 7.79 to 8.96% (mean = 8.28%) dry weight, respectively. Calculated total percentages absorbed were 54.86-62.01 (mean 58.07) carbohydrates 47.33-54.06 (mean = 50.43) protein and 43.27-52.23% (mean 46.56) lipid. Absorption of protein and carbohydrate occurred mostly in the fore-gut (the first one-third of the intestine), while lipid was mostly absorbed in the mid-gut (the second one-third of the intestine). Dietary carbohydrate, protein and lipid contents of the food as well as the absorptive capacity of the intestine for these components of the food varied with size of fis

Isolation and fatty acid profile of selected microalgae strains from the Red Sea for biofuel production

The isolation of lipid-rich autochthonous strains of microalgae is a crucial stage for the development of a microalgae-based biofuel production plant, as these microalgae already have the necessary adaptations to withstand competition, predation and the temperatures observed at each production site. This is particularly important in extreme climates such as in Saudi Arabia. Resorting to fluorescence activated cell sorting (FACS) we screened for and isolated several microalgal strains from samples collected from the Red Sea. Relying on the fluorescence of BODIPY 505/515 (4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diazasindacene) and growth performance, four promising candidates were identified and the total lipid content and fatty acid profile was assessed for biofuels production. Selected isolates were classified as chlorophytes, belonging to three different genera: Picochlorum, Nannochloris and Desmochloris. The lipid contents were assessed microscopically by means of BODIPY 505/515-associated fluorescence to detect intracellular lipid bodies, which revealed several lipid drops in all selected strains. This result was confirmed by lipid gravimetric determination, which demonstrated that all strains under study presented inner cell lipid contents ranging from 20% to 25% of the biomass dry weight. Furthermore, the fatty acid methyl esters profile of all strains seems ideal for biodiesel production due to a low degree of polyunsaturated fatty acid methyl esters and high amount of palmitic and oleic acids.NPST Program of King Saud University [11-ENE1719-02]info:eu-repo/semantics/publishedVersio

Surimi based dried fish cake

Minced fish prepared from the fillets of the sciaenid fish (Lutjanus sp.) was washed with cold water (<10 °C) three times. The washed muscle was pressed through a piece of fine cloth to a moisture content around 80%. The pressed cake (Surimi) was ground with 2.5% sodium chloride and 3% tapioca starch. The mixed material was shaped in the form of a cake and left for one hour for the gel to set. The cakes were then steamed. The cooled cakes were cut into pieces of 1 cm length x 1 cm width x 0.5 cm thick. The pieces were either dried in an electrical oven at 50°C or dried in sun to a moisture content of 11-12%. Biochemical, bacteriological and organoleptic evaluation revealed that the cakes were in very good acceptable form for 8 months. The cakes could be rehydrated by soaking in water at ambient temperature for half an hour and boiling in water for 10 minutes

Growth performance, biochemical composition and sedimentation velocity of Tetraselmis sp. CTP4 under different salinities using low-cost lab- and pilot-scale systems

Biomass harvesting is one of the most expensive steps of the whole microalgal production pipeline. Therefore, the present work aimed to understand the effect of salinity on the growth performance, biochemical composition and sedimentation velocity of Tetraselmis sp. CTP4, in order to establish an effective low-cost pilot-scale harvesting system for this strain. At lab scale, similar growth performance was obtained in cultures grown at salinities of 5, 10 and 20 g L-1 NaCl. In addition, identical settling velocities (2.4-3.6 cm h-1) were observed on all salinities under study, regardless of the growth stage. However, higher salinities (20 g L-1) promoted a significant increase in lipid contents in this strain compared to when this microalga was cultivated at 5 or 10 g L-1 NaCl. At pilot-scale, cultures were cultivated semi-continuously in 2.5-m3 tubular photobioreactors, fed every four days, and stored in a 1-m3 harvesting tank. Upon a 24-hour settling step, natural sedimentation of the microalgal cells resulted in the removal of 93% of the culture medium in the form of a clear liquid containing only vestigial amounts of biomass (0.07 ± 0.02 g L-1 dry weight; DW). The remaining culture was recovered as a highly concentrated culture (19.53 ± 4.83 g L-1 DW) and wet microalgal paste (272.7 ± 18.5 g L-1 DW). Overall, this method provided an effective recovery of 97% of the total biomass, decreasing significantly the harvesting costs.Agência financiadora Portuguese national budget P2020 Foundation for Science and Technology (FCT) CMAR/Multi/04326/2013 ALGARED+ 1398 EP - INTERREG V-A Espana Portugal project ALGACO2 project 023310 COST Action 1408 - European Network for Bio-products FCT SFRH/BD/105541/2014info:eu-repo/semantics/publishedVersio

The duration of the outdoor rearing period of pigs influences Iberian ham characteristics

peer-reviewedThe effect of outdoor rearing duration (75 v 50 days) and rearing system (outdoor v indoor based systems) of Iberian pigs on the chemical composition (fatty acid composition of fat and intramuscular fat, moisture, salt, pigment concentrations and water activity of lean meat), the instrumental colour (CIEL*a*b* system) and the sensory characteristics (descriptive analysis) of dry-cured hams were investigated. The fatty acid composition of subcutaneous fat was weakly affected by outdoor rearing duration, but greatly affected by rearing system with the indoor hams showing larger proportion of saturated fatty acids than outdoor rearing. Rearing system also affected L* of subcut aneous fat (the indoor hams were lighter than the outdoor ones). The instrumental colour of lean was only affected by outdoor rearing duration (scores for a* and its derived variables were larger in the long-outdoor group than in the short-outdoor one). The effect of outdoor rearing duration on the sensory characteristics of Iberian hams was marked, 13 sensory characteristics being affected. Among them, odour intensity, flavour intensity, and flavour persistence were greater in the long-outdoor hams than in the short-outdoor ones, whereas these characteristics were not affected by rearing system. However, rearing system also had a large effect influencing 12 sensory characteristics

Direct extraction of oil from sunflower seeds by twin-screw extruder according to an aqueous extraction process: Feasibility study and influence of operating conditions

The objective of this study was to evaluate the feasibility of an aqueous process to extract sunflower seed oil using a co-rotating twin-screw extruder. Aqueous extraction was carried out using whole seeds and the influence of the operating conditions on oil yield was examined. Operating conditions included screw profile, screw rotation speed, and input flow rates of sunflower seeds and water. Liquid/solid separation required the addition of a lignocellulosic residue upstream from the filtration zone. However, even with maximum fiber input flow, drying of the cake meal did not improve. The lixiviation of the sunflower seeds was also incomplete. The aqueous extraction of the oil was more efficient in the twin-screw extruder than the reference trial conducted in a batch reactor. The best oil extraction yield obtained was approximately 55% and the residual oil content of the cake meal was approximately 30%. The hydrophobic phases produced were oil-in-water emulsions. These emulsions were stabilized by phospholipids and proteins at the interface, which are natural surface-active agents co-extracted during the process

Pengaruh Jenis Pelarut Pada Ekstraksi Asam Lemak Dari Mikroalga

Microalgae are lipid-producing microorganisms that have the potential to be developed as an alternative raw material for biodiesel production. To become biodiesel raw material, several stages of treatment must be carried out. One of the treatments that must be done is to extract the fatty acids contained in the microalgae. In this study, we wanted to find out which type of solvent was the best for extracting fatty acids from microalgae nanochloropsis. The extraction method used was sonication with variations in the length of time 30,60 and 90 minutes, then continued with maceration for 24 hours. The type of solvent used is hexane, methanol and chloroform. The selection of this type of solvent is based on the difference in the polarity of the solvent

Determination of the urinary aglycone metabolites of vitamin K by HPLC with redox-mode electrochemical detection

We describe a method for the determination of the two major urinary metabolites of vitamin K as the methyl esters of their agyclone structures, 2-methyl-3-(3-3-carboxymethylpropyl)-1,4-naphthoquinone (5C-side-chain metabolite) and 2-methyl-3-(5-carboxy-3-methyl-2-pentenyl)-1,4-naphthoquinone (7C-side-chain metabolite), by HPLC with electrochemical detection (ECD) in the redox mode. Urinary salts were removed by reversed-phase (C18) solid phase extraction (SPE) and the predominately conjugated vitamin K metabolites hydrolysed with methanolic HCl. The resultant carboxylic acid aglycones were quantitatively methylated with diazomethane and fractionated by normal-phase (silica) SPE. Final analysis was by reversed-phase (C18) HPLC with a methanol-aqueous mobile phase. Metabolites were detected by amperometric, oxidative ECD of their quinol forms, which were generated by post-column coulometric reduction at an upstream electrode. The assay gave excellent linearity (r2 typically = 0.999) and high sensitivity with an on-column detection limit of <3.5 fmol (<1pg). The inter-assay precision was typically 10%. Metabolite recovery was compared to that of an internal standard (2-methyl-3-(7'-carboxy-heptyl)-1,4-naphthoquinone), added to urine samples just before analysis. Using this methodology we confirmed that the 5C- and 7C-metabolite were major catabolites of both phylloquinone (vitamin K1) and menaquinones (vitamin K2) in humans. We propose that the measurement of urinary vitamin K metabolite excretion is a candidate non-invasive marker of total vitamin K status