Biochar mitigation of soil acidification and carbon sequestration is influenced by materials and temperature.

The alleviation effects on soil acidification by different raw materials and pyrolysis temperatures can broaden the utilization of biochar. In this study, nine types of biochar produced from three raw materials, namely fruit tree branch, peanut shell, and cow dung, at three pyrolysis temperatures (300, 450, and 600 °C) were used to amend acidified brown soil; the rape growth, physiology character, soil chemical and microbial, along with soil organic carbon mineralization were also investigated. The results showed that application of biochar increased soil pH by 8.48-79.25% and reduced exchangeable acidity, exchangeable Al, and exchangeable H by 56.94-94.95%, 34.38-95.66%, and 58.72-93.27%, respectively. Biochar alleviated oxidative stress in plants, reduced malondialdehyde and glutathione content in leaves, promoted rape growth, and increased microbial community diversity and the relative abundances of Acidobacteria and Olpidiomycota in the acidic soil. Moreover, biochar reduced the mineralization rate of organic carbon and the proportion of mineral-bonded organic carbon. Overall, biochar application is an effective strategy to ameliorate soil acidification and enhance rape production and carbon sequestration. The mitigation effect of branch biochar and cow dung biochar on soil acidification was superior to that of peanut shell biochar. The effects of biochar depended on the pyrolysis temperature; the positive effects of biochar samples pyrolyzed at 450 and 600 â„ƒ were stronger than those pyrolyzed at 300 â„ƒ. In this study, the optimum biochar materials and carbonization temperature for acidified soil improvement, as well as the effects of biochar application on soil microbial and carbon mineralization were clarified, which provides a new potential strategy for acidified soil improvement and expand the application range of biochar.

Effects of media components and agricultural by-products on γ-polyglutamic acid production by Bacillus toyonensis As8.

BACKGROUND: Poly-γ­glutamic acid (γ­PGA) provides an environmentally friendly alternative to plastic materials which have widely polluted the environment. OBJECTIVES: The microbial production of γ­PGA, an amino acid biopolymer with glutamic acid subunits, was investigated using renewable agricultural residues in an attempt to find cheaper substitutes for conventional synthetic media components. MATERIAL AND METHODS: Bacteria which produce γ­PGA were isolated through depolymerizing Coix lacryma-jobi, a cellulosic grass, and the effects of various carbon and nitrogen sources, temperature, inoculant load, incubation period, and pH on γ­PGA yield were determined after submerged fermentation. Bacterial growth was measured turbidimetrically at 550 nm. The γ­PGA produced was characterized using Fourier transform infrared (FT-IR) spectroscopy and the polymer shape was determined using scanning electron microscopy (SEM). RESULTS: The best γ­PGA producer was molecularly identified as Bacillus toyonensis As8. The conditions which produced the highest γ­PGA yield were glucose, ammonium sulfate, 25°C, a pH of 5.5, and an incubation period of 48 h. This bacterium yielded the most γ­PGA (26.45 g/L) on cassava peels, while other agro-wastes (corn cob, sorghum leaves, Coix noir leaves, and rice bran) also supported bacterial growth with lower γ­PGA yields than conventional carbon sources. The wrinkled γ­PGA had absorbance peaks of hydroxyl, amide, carbonyl, and amine groups comparable with the ranges of those found in commercial γ­PGA. CONCLUSIONS: The use of agricultural by-products as fermentation substrates increased γ­PGA yield and may therefore be used as substitute components in γ­PGA production.

Predicting Crystallization Propensity of Proteins from Arabidopsis Thaliana.

BACKGROUND: Many studies have correlated characteristics of amino acids with crystallization propensity, as part of the effort to determine the factors that affect the propensity of protein crystallization. However, these characteristics are constant; that is, the encoded amino acid sequences have the same value for each type of amino acid. To overcome this inflexibility, three dynamic characteristics of amino acids and protein were introduced to analyze the crystallization propensity of proteins. Both logistic regression and neural network models were used to correlate each of two dynamic characteristics with the crystallization propensity of 301 proteins from Arabidopsis thaliana, and their results were compared with those obtained from each of 531 constant amino acid characteristics, which served as the benchmark. RESULTS: The neural network model was more powerful for predicting the crystallization propensity of proteins than the logistic regression model. Compared with the benchmark, the dynamic characteristics of amino acids provided good prediction results for the crystallization propensity, and the distribution probability gave the highest sensitivity. Using 90 % accuracy as a cutoff point, the predictable portion of A. thaliana portions was ranked, and the statistical analysis showed that the larger the predictable portion, the better the prediction. CONCLUSIONS: These results demonstrate that dynamic characteristics have a certain relationship with the crystallization propensity, and they could be helpful for the prediction of protein crystallization, which may provide a theoretical concept for certain proteins before conducting experimental crystallization.

Physicochemical properties of Malaysian-grown tropical almond nuts (Terminalia catappa).

The seeds of Terminalia catappa from Malaysia were analyzed for their physicochemical properties. The following values were obtained: moisture 6.23 ± 0.09 %, ash 3.78 ± 0.04 %, lipid 54.68 ± 0.14 %, protein 17.66 ± 0.13 %, total dietary fibre 9.97 ± 0.08 %, carbohydrate 7.68 ± 0.06 %, reducing sugar 1.36 ± 0.16 %, starch 1.22 ± 0.15 %, caloric value 593.48 ± 0.24 %. Studies were also conducted on amino acid profile and free fatty acid composition of the seed oil. Results revealed that glutamic acid was the major essential amino acid while methionine and lysine were the limiting amino acids. The major saturated fatty acid was palmitic acid, while the main unsaturated fatty acid was oleic acid followed by linoleic acid. In addition, the seed was rich in sucrose and had trace amount of glucose and fructose. Briefly, the seed was high in proteins and lipids which are beneficial to human.