Vermicomposting of coffee pulp using the earthworm Eisenia fetida: Effects on C and N contents and the availability of nutrients

In Colombia, more than 1 million tons of coffee pulp are produced every year. Its transformation into compost by means of turned piles has led to a final product with poor physical and chemical characteristics and vermicomposting has been suggested as an alternative method of transforming these wastes into a useful organic fertilizer. The ability of the earthworm Eisenia fetida to transform coffee pulp into a valuable compost was evaluated. The influence of bed depth and time on different C fractions, N content and availability of nutrients was studied. The results showed that the C and N contents were not affected by the depth of the bed, whereas time affected both. An increase in the fractionation ratio, determined by calculating the C in the fraction smaller than 100 m as a percentage of C in the samples as a whole, and low values of humic-like substances were recorded during vermicomposting. After ingestion of the pulp by the earthworms, an increase in available P, Ca, and Mg but a decrease in K were detected.     

Impacts of anthropogenic N additions on nitrogen mineralization from plant litter in exotic annual grasslands

Urban regions of southern California receive up to 45 kg N ha^-1 y^-1 from nitrogen (N) deposition. A field decomposition study was done using ¹⁵N-labelled litter of the widespread exotic annual grass Bromus diandrus to determine whether elevated soil N is strictly from N deposition or whether N mineralization rates from litter are also increased under N deposition. Tissue N and lignin concentrations, which are inversely related in field sites with high and low N deposition, determine the rate at which N moves from plant litter to soil and becomes available to plants. The effect of soil N on N movement from litter to soil was tested by placing litter on high and low N soil in a factorial experiment with two levels of litter N and two levels of soil N. The litter quality changes associated with N deposition resulted in faster rates of N cycling from litter to soil. Concentrations of litter-derived N in total N, NH₄⁺, NO₃⁻, microbial N and organic N were all higher from high N/low lignin litter than from low N/high lignin litter. Litter contributed more N to soil NH₄⁺ and microbial N in high N than low N soil. At the end of the study, N mineralized from high N litter on high N soil accounted for 46% of soil NH₄⁺ and 11% of soil NO₃⁻, compared to 35% of soil NH₄⁺ and 6% of soil NO₃⁻ from low N litter on low N soil. The study showed that in high N deposition areas, elevated inorganic soil N concentrations at the end of the summer N deposition season are a result of N mineralized from plant litter as well as from N deposition.     

ADP-Glucose Pyrophosphorylase Is Located in the Plastid and Cytosol in the Pulp of Tropical Banana Fruit (Musa acuminata)

Plant Foods for Human Nutrition - ADP-glucose pyrophosphorylase (AGPase) is a key enzyme of starch synthesis in seeds, tubers and fruits. UDP-glucose pyrophosphorylase (UGPase) is an important...     

Lipids and fatty acids in wild and pond-reared mud crab Scylla serrata (Forsskål) during ovarian maturation and spawning

Wild‐caught and pond‐reared female mud crab Scylla serrata at different stages of ovarian maturation were collected from Samar and Capiz, Philippines. Crabs were categorized into five stages according to the external morphological and microscopic appearance of the most advanced oocytes. The ovaries, hepatopancreas, muscle and newly spawned eggs (NSE) were analysed for lipid class components and fatty acids. Total lipid was higher in pond‐reared than in wild‐caught crabs but increased with ovarian maturation in both groups. Ovarian lipid peaked at the fully mature stage, coinciding with a decline in hepatopancreatic and muscle lipids. Lipid levels declined significantly in spent females. The tissues contained elevated highly unsaturated fatty acids such as arachidonic (20:4n‐6), eicosapentaenoic (20:5n‐3) and docosahexaenoic (22:6n‐3) acids, but at higher levels in late maturing and fully mature ovaries and in NSE. The type of lipid class and fatty acid components in mature ovaries as well as in NSE are generally considered to be indicative of their importance in reproductive physiology and embryonic and larval development.     

The contribution of<Emphasis Type="Italic"> Phragmites australis</Emphasis> litter to methane (CH<Subscript>4</Subscript>) emission in planted and non-planted fen microcosms

The contribution of Phragmites australis (Cav.) Trin. ex Steud. (common reed) litter as an origin of CH ₄-C was studied in a microcosm experiment. ¹⁴C-labelled, dried and ground P. australis root and shoot litter was buried in waterlogged, planted or non-planted fen microcosms. The evolution of ¹⁴CO ₂ and ¹⁴CH ₄ from the pots was monitored during the 35-day experiment. The ¹⁴C activity in the shoots and roots of the plants, soil, and inundation water was also analysed at the end of the experiment. Up to 40% of the released CH ₄-C originated from the added litter, whereas the rest originated from old soil organic matter. The comparison of planted and non-planted pots suggested that the contribution of recent plant-derived C (i.e. root exudates) to CH ₄ emission was negligible. The proportion of litter-derived CH ₄-C was significantly higher in the planted pots, suggesting that the presence of plants enhanced the formation of CH ₄ from litter. The major part of the initial ¹⁴C activity was recovered from the soil. About 3% was recovered from the inundation water, about 10% was emitted as CO ₂, and only <0.01% as CH ₄. However, these results demonstrated that plant litter and old soil organic matter are the major sources of CH ₄-C in fens during the early growth stage of P. australis.     

Dendritic cell stimulation by mycobacterial Hsp70 is mediated through CCR5

An effective host immune response to mycobacterial infection must control pathogen dissemination without inducing immunopathology. Constitutive overexpression of mycobacterial heat shock protein (myHsp70) is associated with impaired bacterial persistence, but the immune-mediated mechanisms are unknown. We found that myHsp70, in addition to enhancing antigen delivery to human dendritic cells, signaled through the CCR5 chemokine receptor, promoting dendritic cell aggregation, immune synapse formation between dendritic cells and T cells, and the generation of effector immune responses. Thus, CCR5 acts as a pattern-recognition receptor for myHsp70, which may have implications for both the pathophysiology of tuberculosis and the use of myHsps in tumor-directed immunotherapy.     

Physicochemical and Enzyme Characterization of Small and Large Starch Granules Isolated from Two Maize Cultivars

In this study, some morphological, physicochemical, and the initial characterization of the starch granule enzymes of blue and white maizes of small and large granules are described. Starch was isolated from blue and white maizes, and the small and large granules were separated. The efficiency of separation was higher in large granules than small of the blue maize starch. The amylose content was slightly greater (1.3%) in large granules than smaller in both starches studied. No differences in the average gelatinization temperature were found between large and small granules, but the enthalpy of gelatinization value was higher in the small granules. The electrophoretic pattern showed that the granule‐bound starch synthase (GBSSI) had higher expression in large than small granules and that explain the higher amylose content in the former granules. The differences showed in the starch biosynthesis enzymes in small and large granules might explain partially the physicochemical and functional properties of maize.     

Identifying nitrogen-efficient potato cultivars for organic farming

In organic farming, nitrogen efficiency of potato might vary among cultivars, even within the same maturity type. We therefore analysed in depth the response to nitrogen of a diverse set of cultivars, grown at different locations (differing in soil type and management) and in four years (differing in temperature and rainfall patterns). Yield increased with an increase in nitrogen supply and with growing later cultivars if the crop cycle lasted long enough. When crops had to be flamed to prevent spread of late blight, late cultivars yielded less than early cultivars, especially under high nitrogen. By measuring the fraction of soil covered by green leaves throughout the growing season and using a model, we analysed canopy development in detail and related nitrogen and genotype sensitive model parameters to tuber yield. In one year with early, temporary drought, model prediction was poor. We observed that cultivars that rapidly established a high maximum soil cover, maintained that maximum for long and senesced slowly, could sustain high yields. When late-blight infection was late, these (mid)-late cultivars showed high agronomic nitrogen use efficiency, but were not (always) high in nitrogen uptake efficiency, accumulation of nitrogen in the tubers or nitrogen utilisation efficiency. When late-blight infection started early, early or mid-late cultivars that rapidly established a high maximum soil cover under low nitrogen availability gave best performance. In most years, early canopy development is responsive to nitrogen, shows genetic variation, and is significantly related to early tuber yield. Nitrogen-efficient cultivars suitable for organic production should have rapid early canopy development, a high agronomic nitrogen use efficiency and nitrogen utilisation efficiency, but a low nitrogen concentration in the tubers.     

Physicochemical Properties of Oat Varieties and Their Potential for Breadmaking

The breadmaking potential of six oat varieties was compared with and related to their physicochemical properties. The most significant differences in the bread characteristics were found in the crumb structure. The varieties Buggy, Energie, and Zorro resulted in good bread quality with an even gas‐cell distribution characterized by a high number of relatively small pores. In contrast, Typhon, Ivory, and Nord 08/311 each had a large hole in the center of the crumb and accordingly poor quality. Breads differed little in specific volume, bake loss, and density. Rheological analysis revealed positive effects of low batter resistance to deformation on oat bread quality. On the basis of the physicochemical characterization, protein and fat contents were identified as key factors responsible for differences observed in bread quality, provided that starch damage and water‐hydration capacity were low. Additionally, high setback and final viscosity, as determined by Rapid Visco Analyser (RVA) analysis, positively affected oat bread quality. High α‐amylase activity was found to influence negatively the breadmaking performance of oats. Overall, protein, fat, dietary fiber content, starch pasting properties, and α‐amylase activity were responsible for the breadmaking properties of oat varieties.     

Direct genetic, maternal genetic, and heterozygosity effects on weaning weight in a Colombian multibreed beef cattle population

The (co)variance components of BW at weaning (WW) were estimated for a Colombian multibreed beef cattle population. A single-trait animal model was used. The model included the fixed effect of contemporary group (sex, season, and year), and covariates including age of calf at weaning, age of cow, individual and maternal heterozygosity proportions, and breed percentage. Direct genetic, maternal genetic, permanent environmental, and residual effects were included as random effects. Direct, maternal, and total heritabilities were 0.23 +/- 0.047, 0.15 +/- 0.041, and 0.19, respectively. The genetic correlation between direct and maternal effects was -0.42 +/- 0.131, indicating that there may be antagonism among genes for growth and genes for maternal ability, which in turn suggests that improving WW by direct and maternal EPD may be difficult. A greater value for the direct heterosis effect compared with the maternal heterosis effect was found. Furthermore, the greater the proportion of Angus, Romosinuano, and Blanco Orejinegro breeds, the less the WW.