Convergent adaptations: bitter manioc cultivation systems in fertile anthropogenic dark earths and floodplain soils in central amazonia

SHIFTING CULTIVATION IN THE HUMID TROPICS IS INCREDIBLY DIVERSE, YET RESEARCH TENDS TO FOCUS ON ONE TYPE: long-fallow shifting cultivation. While it is a typical adaptation to the highly-weathered nutrient-poor soils of the Amazonian terra firme, fertile environments in the region offer opportunities for agricultural intensification. We hypothesized that Amazonian people have developed divergent bitter manioc cultivation systems as adaptations to the properties of different soils. We compared bitter manioc cultivation in two nutrient-rich and two nutrient-poor soils, along the middle Madeira River in Central Amazonia. We interviewed 249 farmers in 6 localities, sampled their manioc fields, and carried out genetic analysis of bitter manioc landraces. While cultivation in the two richer soils at different localities was characterized by fast-maturing, low-starch manioc landraces, with shorter cropping periods and shorter fallows, the predominant manioc landraces in these soils were generally not genetically similar. Rather, predominant landraces in each of these two fertile soils have emerged from separate selective trajectories which produced landraces that converged for fast-maturing low-starch traits adapted to intensified swidden systems in fertile soils. This contrasts with the more extensive cultivation systems found in the two poorer soils at different localities, characterized by the prevalence of slow-maturing high-starch landraces, longer cropping periods and longer fallows, typical of previous studies. Farmers plant different assemblages of bitter manioc landraces in different soils and the most popular landraces were shown to exhibit significantly different yields when planted in different soils. Farmers have selected different sets of landraces with different perceived agronomic characteristics, along with different fallow lengths, as adaptations to the specific properties of each agroecological micro-environment. These findings open up new avenues for research and debate concerning the origins, evolution, history and contemporary cultivation of bitter manioc in Amazonia and beyond.     

Olive mill wastes: Biochemical characterizations and valorization strategies

The olive mill waste generated from olive oil extraction is a major environmental issue, particularly in Mediterranean areas. The extraction of olive oil is achieved through discontinuous or continuous processes. The two processes yield three fractions: a solid residue and two liquid phases (oil and olive mill wastewater). The characterization of these two by-products showed that they are mainly composed of phenolic compounds, carbohydrates, organic acids and mineral nutrients variably distributed depending on the process employed and the agronomic practices. Untreated olive by-products discharged between November and March into the environment are a major ecological issue for olive oil-producing countries due to their high toxic organic loads, low pH, and high chemical and biological demands. In this context, recent research studies highlight on the treatment approaches and valorization options for dealing with olive mill waste residues, predominantly those allowing for the recovery of valuable natural components such as phenolic compounds, dietary fibers, animal feed, biofuel, biogaz, enzymes, polymers and other. The impact of the chemical heterogeneity and water content of olive mill by-products about these processes of valorization and bioconversion is discussed.     

Macromolecular modifications of manioc starch components by extrusion-cooking with and without lipids

Macromolecular structure of manioc starch, extruded without and with lipids (oleic acid, dimodan, soya lecithin and copra) was studied, using chemical, enzymic, viscometric and chromatographic methods. Twin screw extrusion-cooking led to a macromolecular degradation of both amylose and amylopectin. The formation of lower molecular weight material was observed by a decrease of intrinsic viscosities of both components and also by their behaviour on Sepharose CL-2B, whereas no modification of β-amylolysis and iodine-binding capacity could be detected. The macromolecular degradation was increased by higher temperature and screw speed of the extruder, and was decreased by adding lipids during extrusion. Lipids such as fatty acids, mono- and triglycerides have been shown to act as lubricants (each type in its distinctive way). Lipid extraction, by different solvents, appears to have a low efficiency. Although the addition of triglycerides during extrusion reduces the macromolecular degradation, leading to a high solubility, the amylose-lipid complexes reduce the water-soluble fraction. This fraction was shown to be mainly composed of aggregated amylopectin-like material and to be highly stable after successive freeze-thaw cycles.     

The reluctant innovator: orangutans and the phylogeny of creativity

Young orangutans are highly neophobic, avoid independent exploration and show a preference for social learning. Accordingly, they acquire virtually all their learned skills through exploration that is socially induced. Adult exploration rates are also low. Comparisons strongly suggest that major innovations, i.e. behaviours that have originally been brought into the population through individual invention, are made where ecological opportunities to do so are propitious. Most populations nonetheless have large innovation repertoires, because innovations, once made, are retained well through social transmission. Wild orangutans are therefore not innovative. In striking contrast, zoo-living orangutans actively seek novelty and are highly exploratory and innovative, probably because of positive reinforcement, active encouragement by human role models, increased sociality and an expectation of safety. The explanation for this contrast most relevant to hominin evolution is that captive apes generally have a highly reduced cognitive load, in particular owing to the absence of predation risk, which strongly reduces the costs of exploration. If the orangutan results generalize to other great apes, this suggests that our ancestors could have become more curious once they had achieved near-immunity to predation on the eve of the explosive increase in creativity characterizing the Upper Palaeolithic Revolution.     

Integral valorization of two legumes by autohydrolysis and organosolv delignification

Two woody legumes species (Chamaecytisus proliferus L.F. ssp. palmensis and Leucaena diversifolia) were evaluated for integrally exploitation. The raw material was subjected to autohydrolysis under variable operating conditions which provided a liquid phase rich in hemicellulose oligomers and a solid phase that was used to obtain cellulose pulp and paper sheets by using organosolv procedures. The chemical properties of both C. proliferus and L. diversifolia allow their integral exploitation by using a hydrothermal treatment prior to their organosolv pulping with ethanol. The pulp yields obtained are quite high (40.3% for L. diversifolia and 58.2% for C. proliferus), and so are the sugar concentrations in the liquors from the thermal pretreatment (viz. 16.1 and 20.0 g oligomers/l in C. proliferus and L. diversifolia, respectively, and 1.5 and 1.1g xylose/l, respectively, in the two raw materials). The strength-related properties of the paper sheets obtained are acceptable (tensile index 7.76 and 10.77 kN m/kg for C. proliferus and L. diversifolia, respectively and kappa index 31 and 12.5 for C. proliferus and L. diversifolia, respectively), but somewhat worse than those provided by other raw materials such as eucalyptus; however, they can be improved by mechanical refining of the pulp.     

Biocatalysis in ionic liquids for lignin valorization: Opportunities and recent developments

Lignin holds tremendous potential as a renewable feedstock for upgrading to a number of high-value chemicals and products that are derived from the petroleum industry at present. Since lignin makes up a significant fraction of lignocellulosic biomass, co-utilization of lignin in addition to cellulose and hemicelluloses is vital to the economic viability of cellulosic biorefineries. The recalcitrant nature of lignin, originated from the molecule's compositional and structural heterogeneity, however, poses great challenges toward effective and selective lignin depolymerization and valorization. Ionic liquid (IL) is a powerful solvent that has demonstrated high efficiency in fractionating lignocellulosic biomass into sugar streams and a lignin stream of reduced molecular weight. Compared to thermochemical methods, biological lignin deconstruction takes place at mild temperature and pressure while product selectivity can be potentially improved via the specificity of biocatalysts (lignin degrading enzymes, LDEs). This review focuses on a lignin valorization strategy by harnessing the biomass fractionating capabilities of ILs and the substrate and product selectivity of LDEs. Recent advances in elucidating enzyme-IL interactions as well as strategies for improving enzyme activity in IL are discussed, with specific emphases on biocompatible ILs, thermostable and IL-tolerant enzymes, enzyme immobilization, and surface charge engineering. Also reviewed is the protein engineering toolsets (directed evolution and rational design) to improve the biocatalysts' activity, stability and product selectivity in IL systems. The alliance between IL and LDEs offers a great opportunity for developing a biocatalytic route for lignin valorization.     

The evolutionary roots of creativity: mechanisms and motivations

We consider the evolution of cognition and the emergence of creative behaviour, in relation to vocal communication. We address two key questions: (i) what cognitive and/or social mechanisms have evolved that afford aspects of creativity?; (ii) has natural and/or sexual selection favoured human behaviours considered ‘creative’? This entails analysis of ‘creativity’, an imprecise construct: comparable properties in non-humans differ in magnitude and teleology from generally agreed human creativity. We then address two apparent problems: (i) the difference between merely novel productions and ‘creative’ ones; (ii) the emergence of creative behaviour in spite of high cost: does it fit the idea that females choose a male who succeeds in spite of a handicap (costly ornament); or that creative males capable of producing a large and complex song repertoire grew up under favourable conditions; or a demonstration of generally beneficial heightened reasoning capacity; or an opportunity to continually reinforce social bonding through changing communication tropes; or something else? We illustrate and support our argument by reference to whale and bird song; these independently evolved biological signal mechanisms objectively share surface properties with human behaviours generally called ‘creative’. Studying them may elucidate mechanisms underlying human creativity; we outline a research programme to do so.     

Biogas production and valorization by means of a two-step biological process

The scope of this research work was to investigate biogas production and purification by a two-step bench-scale biological system, consisting of fed-batch pulse-feeding anaerobic digestion of mixed sludge, followed by methane enrichment of biogas by the use of the cyanobacterium Arthrospira platensis. The composition of biogas was nearly constant, and methane and carbon dioxide percentages ranged between 70.5–76.0% and 13.2–19.5%, respectively. Biogas yield reached a maximum value (about 0.4 m³_biogas/kgCOD_i) at 50 days-retention time and then gradually decreased with a decrease in the retention time. Biogas CO₂ was then used as a carbon source for A. platensis cultivation either under batch or fed-batch conditions. The mean cell productivity of fed-batch cultivation was about 15% higher than that observed during the last batch phase (0.035 ± 0.006 g_DM/L/d), likely due to the occurrence of some shading effect under batch growth conditions. The data of carbon dioxide removal from biogas revealed the existence of a linear relationship between the rates of A. platensis growth and carbon dioxide removal from biogas and allowed calculating carbon utilization efficiency for biomass production of almost 95%.     

Integral valorization of Leucaena diversifolia by hydrothermal and pulp processing

Wood from the leguminous tree, Leucaena diversifolia, was subjected to hydrothermal treatment (autohydrolysis) at 160-180 °C for 0-30 min followed by ethanol-soda-anthraquinone delignification. The liquid phase contained 18.65 g of sugars per liter, and the solid phase had a gross heating value of 19.083 MJ/kg, but could also be used as a source of cellulose pulp for the production of paper with tear, burst, and tensile indexes of 2.4 N m²/kg, 2.6 MPa m²/kg and 40.7 kN m/kg, respectively. L. diversifolia lends itself readily to valorization for energy production, and also to integral, fractional exploitation by autohydrolysis and ethanol-soda-anthraquinone delignification, which can additionally bring environmental benefits to cropping zones.     

Efficient,environmentally-friendly and specific valorization of lignin: promising role of non-radical lignolytic enzymes

Lignin is the second most abundant bio-resource in nature. It is increasingly important to convert lignin into high value-added chemicals to accelerate the development of the lignocellulose biorefinery. Over the past several decades, physical and chemical methods have been widely explored to degrade lignin and convert it into valuable chemicals. Unfortunately, these developments have lagged because of several difficulties, of which high energy consumption and non-specific cleavage of chemical bonds in lignin remain the greatest challenges. A large number of enzymes have been discovered for lignin degradation and these are classified as radical lignolytic enzymes and non-radical lignolytic enzymes. Radical lignolytic enzymes, including laccases, lignin peroxidases, manganese peroxidases and versatile peroxidases, are radical-based bio-catalysts, which degrade lignins through non-specific cleavage of chemical bonds but can also catalyze the radical-based re-polymerization of lignin fragments. In contrast, non-radical lignolytic enzymes selectively cleave chemical bonds in lignin and lignin model compounds and, thus, show promise for use in the preparation of high value-added chemicals. In this mini-review, recent developments on non-radical lignolytic enzymes are discussed. These include recently discovered non-radical lignolytic enzymes, their metabolic pathways for lignin conversion, their recent application in the lignin biorefinery, and the combination of bio-catalysts with physical/chemical methods for industrial development of the lignin refinery.     

Life cycle assessment of alternatives for waste-solvent valorization: batch and continuous distillation vs incineration

Purpose

The goal and scope of this research is focused on the application of life cycle assessment (LCA) to evaluate two alternatives (batch and continuous distillation and incineration with energy recovery) for the treatment of four waste-solvent mixtures typically produced in the chemical industry: acetonitrile–toluene, acetonitrile–toluene–tetrahydrofuran (THF), ethyl acetate–water and methanol–THF, with several compositions in order to determine the most appropriate technology depending on the characteristics of the mixture.

Materials and methods

Ecosolvent® v.1.0.1 software is used to perform the LCA, considering two scenarios and the following methods of impact assessment: Eco-indicator 99, cumulative energy demand, method of ecological scarcity (UBP’97), global warming potential and CO₂ balances.

Results and discussion

Results show that distillation gives more environmental credits for the recovery of the most concentrated compound in acetonitrile–toluene mixtures. However, when THF is present in the waste solvent even in small quantities, it has to be recovered due to the high impact associated to its manufacture. Regarding the mixture ethyl acetate–water, distillation takes advantage at concentrations of ethyl acetate higher than 50 wt%, and for the mixture methanol–THF, recovery of methanol is not advantageous from an environmental point of view, but the recovery of THF is clearly necessary to decrease the total impact.

Conclusions

From this study, it can be concluded that those compounds that yield a great environmental burden during the production step should be always recovered in order to minimize the total impact, even if they represent the minor concentration in the mixture. In case that similar impact is produced during the solvent production, the major compound in the mixture should be the target for recovery.

     

Cognitive neuroscience of creativity: EEG based approaches

Cognitive neuroscience of creativity has been extensively studied using non-invasive electrical recordings from the scalp called electroencephalograms (EEGs) and event related potentials (ERPs). The paper discusses major aspects of performing research using EEG/ERP based experiments including the recording of the signals, removing noise, estimating ERP signals, and signal analysis for better understanding of the neural correlates of processes involved in creativity. Important factors to be kept in mind to record clean EEG signal in creativity research are discussed. The recorded EEG signal can be corrupted by various sources of noise and methodologies to handle the presence of unwanted artifacts and filtering noise are presented followed by methods to estimate ERPs from the EEG signals from multiple trials. The EEG and ERP signals are further analyzed using various techniques including spectral analysis, coherence analysis, and non-linear signal analysis. These analysis techniques provide a way to understand the spatial activations and temporal development of large scale electrical activity in the brain during creative tasks. The use of this methodology will further enhance our understanding the processes neural and cognitive processes involved in creativity.     

Crucibles of creativity: the geographic origins of tropical molluscan innovations

Extralimital traits—evolutionary innovations that represent unprecedented departures from the phenotypic norm in the clade in which they arise—are often thought preferentially to evolve in island-like settings, but accumulating evidence indicates that they also arise in highly diverse, competitively rigorous ecosystems. In order to evaluate the origins of extralimital traits, I reconstructed the history of all ecological and shell-morphological innovations in Miocene to Recent shallow-water molluscs from the two great modern tropical marine realms, the Indo-West Pacific (IWP) and Atlantic-eastern Pacific (AEP), with the expectation that the more diverse IWP would show a higher incidence of innovation. Of the 66 innovations I identified, 53 (80%) are IWP and 13 (20%) are AEP in origin. Data on the numbers of living species in 26 molluscan clades in the two tropical realms indicate that the species ratio (AEP to total number of species 0.32 ± 0.115) exceeds the innovation ratio (AEP to total innovations 0.21). The per-species frequency of innovation is therefore significantly higher in the IWP. None of the innovations is unique to endemic taxa on oceanic islands. I suggest that warm, large, highly productive environments are more conducive to the establishment of new ecological roles and phenotypic states than are smaller, less productive, more island-like settings; and that diversity need not be correlated with either high productivity or evolutionary opportunity for innovation.     

Starch granule size and the domestication of manioc (Manihot esculenta) and sweet potato (Ipomoea batatas)

Archaeological studies of plant remains have indicated that an increase in seed size is frequently correlated with both intensive cultivation and domestication of seed crop plants. To test if starch granules of domesticated root crops are significantly larger than those of wild or less intensively cultivated plants, archaeological and modern specimens of manioc and sweet potato were sampled for starch granules, and granule size was compared across a temporal sequence. The results indicate that a gross generalization can be made that modern specimens of both manioc and sweet potato yield larger starch granules than some archaeological specimens. It does appear, however, that modern domesticated manioc roots produce significantly larger-sized starch granules than those of its purported wild ancestor. Additionally, there exist two lines of evidence that the coastal Peruvian and lowland Neotropical regional types of manioc differ from one another and have been separate for several millennia. These findings indicate that manioc may have been domesticated more than once.     

Simultaneous enzymatic saccharification and comminution for the valorization of lignocellulosic biomass toward natural products

Background

Large-scale processing of lignocellulosics for glucose production generally relies on high temperature and acidic or alkaline conditions. However, extreme conditions produce chemical contaminants that complicate downstream processing. A method that mainly rely on mechanical and enzymatic reaction completely averts such problem and generates unmodified lignin. Products from this process could find novel applications in the chemicals, feed and food industry. But a large-scale system suitable for this purpose is yet to be developed. In this study we applied simultaneous enzymatic saccharification and communition (SESC) for the pre-treatment of a representative lignocellulosic biomass, cedar softwood, under both laboratory and large-scale conditions.

Results

Laboratory-scale comminution achieved a maximum saccharification efficiency of 80% at the optimum pH of 6. It was possible to recycle the supernatant to concentrate the glucose without affecting the efficiency. During the direct alcohol fermentation of SESC slurry, a high yield of ethanol was attained. The mild reaction conditions prevented the generation of undesired chemical inhibitors. Large-scale SESC treatment using a commercial beads mill system achieved a saccharification efficiency of 60% at an energy consumption of 50?MJ/kg biomass.

Conclusion

SESC is very promising for the mild and clean processing of lignocellulose to generate glucose and unmodified lignin in a large scale. Economic feasibility is highly dependent on its potential to generate high value natural products for energy, specialty chemicals, feed and food application.

     

Energy valorization of industrial biomass: Using a batch frying process for sewage sludge

This paper studies the energy valorization of sewage sludge using a batch fry–drying process. Drying processes was carried out by emerging the cylindrical samples of the sewage sludge in the preheated recycled cooking oil. Experimental frying curves for different conditions were determined. Calorific values for the fried sewage sludge were hence determined to be around 24 MJ kg⁻¹, showing the auto-combustion potential of the fried sludge. A one-dimensional model allowing for the prediction of the water removal during frying was developed. Another water replacement model for oil intake in the fried sewage sludge was also developed. Typical frying curves were obtained and validated against the experimental data.