The effect of temperature on the ensiling process of corn and wheat

AIMS: The purpose of this work was to study the effect of temperature on the ensiling process and aerobic stability of corn and wheat silages. METHODS AND RESULTS: The crops were ensiled in 1.5 l anaerobic jars, with and without an inoculant, at room or elevated temperatures (37-41 degrees C). After two months of ensiling, the silages were subjected to an aerobic stability test at room and elevated (33 degrees C) temperature. The results indicate that ensiling at elevated temperatures resulted in higher pH values, less lactic acid and higher losses. The silages which were stored at elevated temperatures were more susceptible to aerobic spoilage than those stored at room temperature, especially when the test was performed at elevated temperature. CONCLUSION: High temperatures are detrimental to both the ensiling process and the aerobic stability of silages. SIGNIFICANCE AND IMPACT OF THE STUDY: The findings of the current study suggest that in a warm climate, special care should be taken during silage making and storage in order to avoid heating as much as possible. In addition, in a warm climate, silages are more susceptible to aerobic deterioration and therefore, special care should be taken during unloading.     

高温高湿条件下意大利黑麦草青贮技术研究

研究以水田冬闲期栽培的意大利黑麦草(Lolium multiflorum)为材料,结合常规的青贮方法进行了小规模控制实验,试验设计了隔水(将青贮过程中产生的渗出液排出)和不隔水,以及不同添加物的青贮处理.青贮结束后,对青贮黑麦草的品质和营养价值进行评定,探讨不同处理对黑麦草青贮的作用效果,以及南方高温高湿条件下青贮黑麦草的合理方法和最佳条件.结果发现,对黑麦草进行隔水添加乳酸的青贮处理从感观评定、pH值和营养成分的分析结果来看,都在一定程度上优于其他处理,由此可以认为隔水添加乳酸的处理相对实现了较稳定和较优质的青贮.     

Fermentation dynamics and diversity of bacterial community in four typical woody forages

Woody forage is a new feeding resource used worldwide, and silage is the main long-term storage, mediated by micro-organisms present during their processing. The objectives of our work were to evaluate the fermentation dynamics and to characterize the bacterial community of our typical woody forages. We selected four typical woody forages: paper mulberry (Broussonetia papyrifera), mulberry (Morus alba L.), moringa tree (Moringa oleifera), and Anthocephalus chinensis (Neolamarckia cadamba). The materials were ensiled and sampled after ensiling 1, 3, 5, 7, 15, 30, and 60 days. Our results indicate that woody forages have good forage properties with relatively high crude protein content and low neutral detergent fiber and acid detergent fiber content. However, the water soluble carbohydrate content in paper mulberry was considerably low (18.67 g kg−1), which makes ensiling difficult. The lactic acid and acetic acid contents in each of the four materials were reduced after 3 days of ensiling and increased again after 30 days of ensiling, with the exception of Anthocephalus chinensis. Anthocephalus chinensis and moringa tree were well-preserved after 7 and 60 days of ensiling, respectively, with low pH and ammonia nitrogen content. Cyanobacteria was predominant in moringa tree and Anthocephalus chinensis before ensiling, and Lactobacillus became dominant after 15 days of ensiling. Enterobacter dominated the paper mulberry and mulberry during fermentation process and accelerated their poor silage quality. Therefore, the conformity of bacterial community succession with ensiling parameters guaranteed the final quality of woody forage silages, and this might aid in controlling the manufacturing process.     

An appetite for destruction

Autophagy plays an important role in cellular survival by resupplying cells with nutrients during starvation or by clearing misfolded proteins and damaged organelles and thereby preventing degenerative diseases. Conversely, the autophagic process is also recognized as a cellular death mechanism. The circumstances that determine whether autophagy has a beneficial or a detrimental role in cellular survival are currently unclear. We recently showed that autophagy induction is detrimental in neurons that lack a functional AMPK enzyme (AMP-activated protein kinase) and that suffer from severe metabolic stress. We further demonstrated that autophagy and AMPK are interconnected in a negative feedback loop that prevents excessive and destructive stimulation of the autophagic process. Finally, we uncovered a new survival mechanism in AMPK-deficient neurons—cell cannibalism.     

Influence of nitrogen fertilization on tropical‐grass silage assessed by ensiling process monitoring using chemical and microbial community analyses

Aims: Utilization of silage in livestock farming is expected to increase in developing countries in the tropical and subtropical parts of the world. The aim of this study was to investigate the influence of nitrogen fertilization on the chemical composition of herbage, ensiling process and silage quality, and to contribute to the improvement of tropical‐grass silage preparation. Methods and Results: Guinea grass grown under two different nitrogen‐fertilizer application conditions [1·5 kg N a^?1 (high‐N) and 0·5 kg N a^?1 (low‐N)] was packed in plastic bags, and its ensiling process was investigated by chemical and microbial‐community analyses. Relatively well‐preserved silage was obtained from high‐N herbage, which accumulated a high nitrate concentration. Denaturing gradient gel electrophoresis analysis revealed that Lactobacillus plantarum dominated throughout the ensiling of high‐N herbage and in the early phase of that of low‐N herbage. In low‐N silages prepared from ammonium sulfate‐ and urea‐fertilized herbage, Lact. plantarum was replaced by clostridia after 40 and 15 days of ensiling, respectively. Conclusions: Nitrate content of herbage is an important factor that influences silage quality, and careful fertilization management can facilitate stable and successful fermentation of tropical‐grass silage without any pretreatment. Significance and Impact of the Study: The positive effect of nitrate on the ensiling process of tropical‐grass was proved by microbial‐community analysis.     

Bioconversion of corn straw by coupling ensiling and solid-state fermentation

A two-stage process that combined solid-state fermentation (SSF) and ensiling was used for bioconversion of corn straw, in order to increase nutritional value and palatability for animal feed. SSF of corn straw increased the level of protein from 6.7% to 14.7% and decreased the cellulose by 38.0% and hemicellulose by 21.2%. Cellulase and xylanase were produced during SSF. After SSF, the fermented substrate was directly ensiled by inoculating with lactic acid bacteria (LAB). In situ produced enzymes and bacterial inoculation resulted in a rapid drop in pH, a high level of lactic acid production, partial degradation of cell wall components and generation of reducing sugars (RSs). Efficiency of ensiling at 25 degrees C, 30 degrees C, 35 degrees C, 40 degrees C was evaluated. Temperature influenced the effect of ensiling; the higher the temperature, the shorter the ensiling period. The combined fermentation upgraded the nutritional value, enhanced the efficiency of ensiling and reduced bioprocessing costs.     

Silierung durch aerobe Säuerung – paradoxer Einfall oder praktische lösung?

For ensiling of herbage which is rich in protein and therefore difficult to ferment a procedure is proposed. It is based on aerobic acidification using biological deoxydants. The crops are treated with a suspension of living cells of Acetobacter methanolicus and a water solution of ethanol. This treatment brings about environmental conditions which promote lactic acid fermentation: anaerobiosis, complex nutritional supply and protective concentrations of H⁺-ions. Preliminary attempts have confirmed the principle of conservation by aerobic acidification combined with biological deoxydation in agricultural practice. Damages of legume crops with high protein content are prevented. The advantages of the new ensiling process is discussed in comparison to traditional treatment.     

Fungal survival in ensiled swine faeces

The survival of several genera of fungi was determined in the ensiled solid fraction of swine faeces after 0, 7, 14, 28 and 56 days of ensiling. The experiment had two treatments, un-ensiled and ensiled manure, in a split-plot design. The manure was distributed into 50 containers; samples, taken at the specified times, were cultured in agar potato dextrose medium, incubated, and colony forming units (CFU/g) were counted and log-transformed. The ensiling process decreased the number of CFU after 56 days. Five fungal genera were identified (Absidia spp., Aspergillus spp., Penicillium spp., Rhizopus spp. and non-fructiferous fungi), and their vulnerability to the ensiling conditions varied, although most of them slowed their growth or disappeared after 14 days of ensiling.     

Survival and viability of Ascaris suum and Oesophagostomum dentatum in ensiled swine faeces

The survival and viability of eggs from Ascaris suum and Oesophagostomum dentatum and of infective larvae (L3) from O. dentatum were determined in the ensiled solid fraction of swine faeces after 0, 7, 14, 28 and 56 days of ensiling. The experiment had two treatments, un-ensiled and ensiled manure, in a split-plot design. Each of 50 containers was inoculated with 40,000 eggs of both A. suum and O. dentatum, and another 50 containers were inoculated with 32,747 L3 of O. dentatum each. A. suum eggs were not destroyed by the ensiling process, although their viability was diminished. O. dentatum eggs and larvae were destroyed during the first 7-14 days of the ensiling process.     

Potential of ensiling for efficient management of spent residue from solid state fermentation system

Summary Studies on ensiling of spent solids from solid state fermentation process for production of cellulases byTrichoderma harzianum showed that good quality ensiled solids can be obtained by using about 43% initial substrate dry matter with 0.3% ensiling additive.     

Preservation of potential fermentables in sweet sorghum by ensiling

Pressed and wilted samples of sweet sorghum [Sorghum bicolor (L.) Moench var. Rio] were ensiled for periods up to 155 days. A kinetic study of the biochemical changes which occurred during ensiling showed that in wilted sorghum ensilage invert sugars and mannitol levels collectively were maintained at 65% of the original ferment able sugar content of the sorghum. The acidic environment produced by ensiling also served as a pretreatment that resulted in enhanced yields of reducing sugar when the sorghum was contacted with cellulolytic enzymes. The quantity of sugar obtained from enzymatic hydrolysis more than compensated for carbohydrate used by organisms during the ensiling process. Both Saccharomyces uvarum and Clostridium acetobutylicum were able to ferment a medium constituted from pressed sorghum juice and the solution resulting from enzymatic hydrolysis of sweet sorghum ensilage.     

UNDERSTANDING INTERCELLULAR INTERACTIONS AND CELL ADHESION: LESSONS FROM STUDIES ON PROTEIN—METAL INTERACTIONS

To understand cell—cell interactions and the interactions of cells to non-biological materials, studies on binding forces between cellular proteins and between proteins and non-biological material such as metal surfaces are essential. The adsorption of proteins to solid—water interfaces is a multifactorial and a multistep process. First steps are determined by long-range interactions where surface properties such as hydrophobicity, distribution of charged groups, ion concentrations and pH play important roles. In later steps structural rearrangements in the protein molecule and dehydration effects become more important making the adsorption process often irreversible. In the following we demonstrate that protein A and tubulin have a specific type of interaction to metal surfaces probably as an intermediate step in the adsorption process. The proteins were attached to the tip of a microfabricated cantilever in such a way that only one molecule interacts with the surface. By recording force—distance curves with an atomic force microscope the adhesion forces of single molecules binding to gold, titanium and indium—tinoxid surfaces were measured.     

Criteria for lactic acid bacteria screening to enhance silage quality

The main challenge of ensiling is conserving the feed through a fermentative process that results in high nutritional and microbiological quality while minimizing fermentative losses. This challenge is of growing interest to farmers, industry and research and involves the use of additives to improve the fermentation process and preserve the ensiled material. Most studies involved microbial additives; lactic acid bacteria (LAB) have been the focus of much research and have been widely used. Currently, LABs are used in modern and sustainable agriculture because of their considerable potential for enhancing human and animal health. Although the number of studies evaluating LABs in silages has increased, the potential use of these micro-organisms in association with silage has not been adequately studied. Fermentation processes using the same strain produce very different results depending on the unique characteristics of the substrate, so the choice of silage inoculant for different starting substrates is of extreme importance to maximize the nutritional quality of the final product. This review describes the current scenario of the bioprospecting and selection process for choosing the best LAB strain as an inoculant for ensiling. In addition, we analyse developments in the fermentation process and strategies and methods that will assist future studies on the selection of new strains of LAB as a starter culture or inoculant.     

Particle Size Reduction During Harvesting of Crop Feedstock for Biogas Production II: Effects on Energy Balance, Greenhouse Gas Emissions and Profitability

Reducing chopping length for biogas crop harvesting is a pretreatment method to support the processes of ensiling and methane formation, yet it also increases expenditures at harvest. To assess environmental performance and economic viability, the effects of reducing chopping lengths from common to very short settings on energy balance, greenhouse gas emissions and profitability were investigated. Assessment was based on data gained by monitoring harvesting and ensiling process chains in practice. Balancing results showed low overall effects of chopping length reduction on net energy yield and net greenhouse gas emissions. Shorter chopping length settings reduced net greenhouse gas emissions slightly while net energy yield and profit only increased significantly in 30 to 40?% of the farm-scale harvests investigated. Conditions promoting intensified chopping include the use of high-capacity harvesters, chopping of lignin-rich feedstocks, high subsidies for generated electricity and the utilisation of waste heat. Owing to numerous influencing factors, profitability cannot be guaranteed and so chopping lengths below 7 to 8?mm are not recommended.     

Effect of ensiling on the nutritive value of low quality roughage rice hulls. II. Chemical studies

The sequence of the effects of delayed and immediate sealed silos as well as the role of nutrient additives such as molasses and/or urea in the ensiling process of rice hulls and the subsequent nutritive value of the product has been shown. There were considerable variations in the chemical constituents during the ensiling of rice hulls among the different treatments under both delayed and immediate sealed silos. In all cases, when compared with the controls, the crude protein, soluble sugars, lactic acid, and fat contents were markedly increased, while the carbohydrate polymers and silica contents were significantly decreased. It was concluded that the treatment of rice hulls + 2% molasses for two months ensiling period under anaerobic conditions can be considered as the optimum conditions for the production of good quality silage from the low grade roughages rice hulls. Changes in pH values also confirmed the improving effect of the combination of molasses addition and the immediate sealing of the silos.     

Mathematical models of neuronal growth

Biomechanics and Modeling in Mechanobiology - The establishment of a functioning neuronal network is a crucial step in neural development. During this process, neurons extend neurites—axons...     

Ensiling olive cake with and without molasses for ruminant feeding

The purpose of the current experiment was to study the ensiling properties of olive cake with and without added molasses at 2-6% (w/w). The results indicate that molasses enhanced the ensiling fermentation of olive cake, as evidenced from higher lactic acid content and higher lactic acid bacteria numbers at 4% and 6% added molasses. However, when applied at 4% and 6% molasses increased fermentation losses up to 9.4%, probably due to larger yeast population. Polyphenols which could interfere with protein utilization by ruminants, decreased during ensiling by about 40%. It is concluded that molasses added at 3% could improve the ensiling fermentation of olive cake without substantial losses.     

Bacterial community dynamics during the ensilage of wilted grass

Aims:  Grass silage is the product formed by a natural lactic acid bacterial fermentation when grass is stored under anaerobic conditions, and represents an important ruminant feedstuff on farms during winter. Of the two commonly employed methods of ensiling forage, baled silage composition frequently differs from that of comparable precision-chop silage reflecting a different ensiling environment. The aim of this study was to investigate the dynamics of the silage fermentation in wilted grass and between ensiling systems.
Methods and Results:  Fermentation dynamics were examined using traditional methods of silage analyses, including microbial enumeration and analysis of fermentation products, and culture-independent terminal restriction fragment length polymorphism (T-RFLP). A successful fermentation was achieved in both systems, with the fermentation (increase in lactic acid bacteria and lactic acid concentration, decrease in pH) proceeding rapidly once the herbage was ensiled.
Conclusions:  Under controlled conditions, little difference in silage quality and microbial composition were observed between ensiling systems and this was further reflected in the T-RFLP community analysis.
Significance and Impact of the Study:  T-RFLP proved a potentially useful tool to study the ensilage process and could provide valid support to traditional methods, or a viable alternative to these methods, for investigating the dynamics of the bacterial community over the course of the fermentation.     

The late stage of autophagy: cellular events and molecular regulation

Autophagy is an intracellular degradation system that delivers cytoplasmic contents to the lysosome for degradation. It is a “self-eating” process and plays a “house-cleaner” role in cells. The complex process consists of several sequential steps—induction, autophagosome formation, fusion of lysosome and autophagosome, degradation, efflux transportation of degradation products, and autophagic lysosome reformation. In this review, the cellular and molecular regulations of late stage of autophagy, including cellular events after fusion step, are summarized.     

Synergetic effect of freeze-drying and gamma irradiation on the mechanical properties of human cancellous bone

Freeze-drying and irradiation are common process used by tissue banks to preserve and sterilize bone allografts. Freeze dried irradiated bone is known to be more brittle. Whether bone brittleness is due to irradiation alone, temperature during irradiation or to a synergetic effect of the freeze-drying-irradiation process was not yet assessed. Using a left–right femoral head symmetry model, 822 compression tests were performed to assess the influence of sequences of a 25 kGy irradiation with and without freeze-drying compared to the unprocessed counterpart. Irradiation of frozen bone did not cause any significant reduction in ultimate strength, stiffness and work to failure. The addition of the freeze-drying process before or after irradiation resulted in a mean drop of 35 and 31% in ultimate strength, 14 and 37% in stiffness and 46 and 37% in work to failure. Unlike irradiation at room temperature, irradiation under dry ice of solvent–detergent treated bone seemed to have no detrimental effect on mechanical properties of cancellous bone. Freeze-drying bone without irradiation had no influence on mechanical parameters, but the addition of irradiation to the freeze-drying step or the reverse sequence showed a detrimental effect and supports the idea of a negative synergetic effect of both procedures. These findings may have important implications for bone banking.