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An Olympus CKX41 inverted microscope connected to a digital camera (Motic 5.0) was used. Also, three electron microscopes were used: - Quanta FEG 250 (FEI, Hillsboro, Oregon, USA) in the laboratory of CIEN-UC, Facultad de Física, Pontificia Universidad Católica de Chile. - Quanta 250 (FEI, Hillsboro, Oregon, USA) in the laboratory of MEM, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile. - Quanta Inspect F50 (FEI, Hillsboro, Oregon, USA) in the laboratory of UICMA, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile. Images of main microplanktonic items (folders) obtained under inverted (mostly) and electronic microscope used to estimate biovolume and carbon biomass. Scale bar is shown on each picture and label of each image indicate the station ID (St.) and sampling depth (m). A table is provided with biovolume and equivalent spherical diameter calculations for each planktonic item.

Food provides energy and nutrients, but its acquisition requires energy expenditure. In post-hunter-gatherer societies, extra-somatic energy has greatly expanded and intensified the catching, gathering, and production of food. Modern relations between energy, food, and health are very complex, raising serious, high-level policy challenges. Together with persistent widespread under-nutrition, over-nutrition (and sedentarism) is causing obesity and associated serious health consequences. Worldwide, agricultural activity, especially livestock production, accounts for about a fifth of total greenhouse-gas emissions, thus contributing to climate change and its adverse health consequences, including the threat to food yields in many regions. Particular policy attention should be paid to the health risks posed by the rapid worldwide growth in meat consumption, both by exacerbating climate change and by directly contributing to certain diseases. To prevent increased greenhouse-gas emissions from this production sector, both the average worldwide consumption level of animal products and the intensity of emissions from livestock production must be reduced. An international contraction and convergence strategy offers a feasible route to such a goal. The current global average meat consumption is 100 g per person per day, with about a ten-fold variation between high-consuming and low-consuming populations. 90 g per day is proposed as a working global target, shared more evenly, with not more than 50 g per day coming from red meat from ruminants (ie, cattle, sheep, goats, and other digastric grazers).

The main challenge for partial nitrification is to reach stable nitrite accumulation, which strongly depends on the nitrite-oxidizing bacteria (NOB) growth in the reactor. The on-line estimation of active biomass may enhance the decision-making process to maintain a high nitrite accumulation in the reactor. In this work, we propose an active biomass estimator based on ASM1 and on-line oxygen uptake rate measurements (OUR-E) in a sequencing batch reactor. In order to validate the OUR-E, two operating scenarios were applied during 200 days of operation: unfavorable (sludge retention time (SRT) = 40 d, pH = 7.6, dissolved oxygen (DO) = 2 mg/L) and favorable for partial nitrification (SRT = 10 d, pH = 8.5, DO = 2 mg/L). Furthermore, a second estimation method based on off-line measurements of N-species concentrations (Nsp-E) was implemented to evaluate the performance of the OUR-E. The OUR-E was able to predict a reduction in the NOB active fraction from 10.3% to 1.6% with nitrite accumulation over 80% when we shifted the operating scenario. Although both estimators predicted similar results, the OUR-E showed a better prediction quality than the Nsp-E, according to Theil's coefficient of inequality.

Biomaterials based on crosslinked sponges of biopolymers have been extensively used as scaffolds to culture mammal cells. It is well known that single biopolymers show significant change over time due to a phenomenon called physical ageing. In this research, it was verified that scaffolds used for skin tissue engineering (based on gelatin, chitosan and hyaluronic acid) express an ageing-like phenomenon. Treatments based on ageing of scaffolds improve the behavior of skin-cells for tissue engineering purposes. Physical ageing of dry scaffolds was studied by differential scanning calorimetry and was modeled with ageing kinetic equations. In addition, the physical properties of wet scaffolds also changed with the ageing treatments. Scaffolds were aged up to 3 weeks, and then skin-cells (fibroblasts) were seeded on them. Results indicated that adhesion, migration, viability, proliferation and spreading of the skin-cells were affected by the scaffold ageing. The best performance was obtained with a 2-week aged scaffold (under cell culture conditions). The cell viability inside the scaffold was increased from 60% (scaffold without ageing treatment) to 80%. It is concluded that biopolymeric scaffolds can be modified by means of an ageing treatment, which changes the behavior of the cells seeded on them. The ageing treatment under cell culture conditions might become a bioprocess to improve the scaffolds used for tissue engineering and regenerative medicine.

The aim of the study was to asses the plough effects in the above and below ground biomass Eucalyptus globulus plantations. At the same time the root damage was evaluated. The project was carried out in two experimental stands, three trees were chosen by stand and plought treatment. The above ground biomass was determining harvesting the tree. The coarse and fine root were evaluated in 3.6 and 0.688 m3 of soil volume, respectively. Furthermore the root damage were analized in 50 trees. Afterward the predawn leaf water potential were determining in plough and unplough trees. The total above ground biomass have not statistical differences between treatments. The coarse roots represent a high percentage of the below ground biomass and the fine root biomass is higher near the stump. The plough effect was concentrated within the 0-20 cm soil profile. In the plough assay the amount of fine root was higher in the undisturbed than in ploughed soil. Greater part of more superficial fine roots were cuted and linearly decrease the predawn leaf water potential when increase the root damage.

SignificanceMarine fisheries provide a major global source of protein, feeding billions of people, but they face destabilization in many regions from overexploitation and climate change. Using the most comprehensive dataset of fish diversity and abundance, encompassing over 4,500 surveys from nearshore habitats around the world, we show that biodiversity is among the strongest predictors of reef fish community biomass, comparable in importance to global temperature gradients and human impacts. Importantly, diverse fish communities were more resistant to rising and variable temperature, suggesting that high biodiversity also buffers against changing climate. Maintaining taxonomically and functionally diverse fish communities can thus stabilize fisheries’ yields in a changing ocean.

The chemical characteristics of mine tailings, organic amendments (doses), and plants are the critical factors that must be evaluated and monitored to ensure the sustainability of phytostabilization. The aim of this study was to evaluate the mobility of copper (Cu) in mine tailings (MT) of the Zone Central of Chile to which commercial humic substances were added, examining their effect on the uptake of Atriplex halimus. Two commercial humic substances (HS1 and HS2) extracted from leonardite (highly oxidized lignite), of different pH and total organic carbon, were evaluated by adsorption curve for Cu. In columns, soluble Cu, pH, and electrical conductivity in leachates were evaluated for MT, MT + HS1, and MT + HS2, and HS1 and HS2 in doses of 120 mg kg-1. In pot assay, seeds were germinated directly in MT and cultivated for 140 days with the addition of HS2 in 120 and 240 mg kg-1. Mine tailing presents high concentration of Cu (2016 ± 223 mg kg-1, pH 6.3 ± 0.1). The results of sequential extraction indicate that Cu is associated with the sulfide fraction of low risk of mobility. The amount of Cu sorbed by HS1 was higher than that sorbed by HS2, and both humic substances showing better fit to the Freundlich than Langmuir model. Lixiviation of Cu was significantly lower in MT + HS1 (0.166 ± 0.043 mg kg-1) and MT + HS2 (0.157 ± 0.018 mg kg-1) than in MT (0.251 ± 0.052 mg kg-1). Copper concentration in plants reached 185.8 ± 37.8 mg kg-1 in the roots and 32.6 ± 7.4 mg kg-1 in the aerial parts cultivated in MT without effect of the humic substance addition in Cu uptake nor growth. Copper concentrations in the aerial parts were adjusted to sufficient or normal levels in plant. A good management of mine tailings through phytostabilization could consider an adequate mixture of humic substances (to avoid leaching of metals) and an organic amendment that provides essential nutrients and increases biomass generation.

The development of an effective, realistic, and sustainable microbial biorefinery depends on several factors, including as one of the key aspects an adequate selection of microbial strain. The oleaginous red yeast Rhodotorula sp. has been studied as one powerful source for a plethora of high added-value biomolecules, such as carotenoids, lipids, and enzymes. Although known for over a century, the use of Rhodotorula sp. as resource for valuable products has not yet commercialized. Current interests for Rhodotorula sp. yeast have sparked from its high nutritional versatility and ability to convert agro-food residues into added-value biomolecules, two attractive characteristics for designing new biorefineries. In addition, as for other yeast-based bioprocesses, the overall process sustainability can be maximized by a proper integration with subsequent downstream processing stages, for example, by using eco-friendly solvents for the recovery of intracellular products from yeast biomass. This review intends to reflect on the current state of the art of microbial bioprocesses using Rhodotorula species. Therefore, we will provide an analysis of bioproduction performance with some insights regarding downstream separation steps for the extraction of high added-value biomolecules (specifically using efficient and sustainable platforms), providing information regarding the potential applications of biomolecules produced by Rhodotorula sp, as well as detailing the strengths and limitations of yeast-based biorefinery approaches. Novel genetic engineering technologies are further discussed, indicating some directions on their possible use for maximizing the potential of Rhodotorula sp. as cell factories. KEY POINTS: • Rhodotorula sp. are valuable source of high value-added compounds. • Potential of employing Rhodotorula sp. in a multiple product biorefinery. • Future perspectives in the biorefining of Rhodotorula sp. were discussed.