Organoarsenic arsanilic acid (ASA) contamination of paddy soil is a serious but less concerned hazard to agriculture and health of people consuming rice as staple food, for rice is one major pathway of arsenic (As) exposure to human food. To date little research has studied the effect of ASA on biochemical process of rice. Silicon (Si) application is able to reduce the toxicities of heavy metals in numerous plants, but little information about ASA. This work investigated whether and how Si influenced alleviation of ASA toxicity in rice at biochemical level to have a better understanding of defense mechanism by Si against ASA stress. Results showed that ASA reduced rice growth, disturbed protein metabolism, increased lipid peroxidation but decreased the efficiencies of antioxidant activities compared to control plants, more severe in roots than in shoots. The addition of Si in ASA-stressed rice plants noticeably increased growth and development as well as soluble protein contents, but decreased malondialdehyde (MDA) contents in ASA-stressed rice plants, suggesting that Si did have critical roles in ASA detoxification in rice. Furthermore, increased superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities along with elevated glutathione (GSH) and ascorbic acid (AsA) contents implied the active involvement of ROS scavenging and played, at least in part, to Si-mediated alleviation of ASA toxicity in rice, and these changes were related to rice genotypes and tissues. The study provided physio-chemical mechanistic evidence on the beneficial effect of Si on organoarsenic ASA toxicity in rice seedlings.

微生物污染是鲜切蔬菜最重要的安全风险,也是消费者关注的热点问题.本文针对鲜切蔬菜的生产关键控制点,从原料生产控制、 原料分拣与预冷、 清洗与灭菌、 切分和整理、 包装与贮藏、 人员与环境卫生等环节对鲜切蔬菜的微生物污染来源进行识别分析,并综述了其主要控制措施.

通过对砷及其形态的化学—生物特征、海产品中砷形态的毒性及其机制、存储和处理过程中砷形态浓度和稳定性变化等研究的综合分析,研究了海产品中砷形态毒理代谢规律及砷毒性与其生物转化行为的相关性,发现海产品中砷形态形成机制的研究对于控制海产品中的砷污染、确保海产品的质量安全和人体健康都有非常重要的作用,而砷的生物转化途径仍需要进行更深入的研究分析.

P-arsanilic acid (AsA) is a emerging but less concerned contaminant used in animal feeding operations, for it can be degraded to more toxic metabolites after being excreted by animals. Rice is the staple food in many parts of the world, and also more efficient in accumulating arsenic (As) compared to other cereals. However, the uptake and transformation of AsA by rice is unclear. This study aimed to evaluate the potential risk of using AsA as a feed additive and using the AsA contaminated animal manure as a fertilizer. Five rice cultivars were grown in soil containing 100mg AsA/kg soil, after harvest, As species and their concentrations in different tissues were determined. Total As concentration of the hybrid rice cultivar was more than conventional rice cultivars for whole rice plant. For rice organs, the highest As concentration was found in roots. AsA could be absorbed by rice, partly degraded and converted to arsenite, monomethylarsonic acid, dimethylarsinic acid, arsenate. The number of As species and their concentrations in each cultivar were related to their genotypes. The soil containing 100mg AsA/kg or more is unsuitable for growing rice. The use of AsA and the disposal of animal manure requires detailed attention.

In this study, one- and two-step pretreatments with alkali and acid were performed in the three Miscanthus species that exhibit distinct hemicelluloses levels. As a result, one-step with 4% NaOH or two-step with 2% NaOH and 1% H2SO4 was examined to be optimal for high biomass saccharification, indicating that alkali was the main effecter of pretreatments. Notably, both one- and two-step pretreatments largely enhanced biomass digestibility distinctive in hemicelluloses-rich samples by effectively co-extracting hemicelluloses and lignin. However, correlation analysis further indicated that the effective lignin extraction, other than the hemicelluloses removals, predominately determined biomass saccharification under various alkali and acid pretreatments, leading to a significant alteration of cellulose crystallinity. Hence, this study has suggested the potential approaches in bioenergy crop breeding and biomass process technology.

A-Type and B-type oligomeric proanthocyanidins were prepared from the 70% ethanol extract of peanut skin by purification on AB-8 macroporous adsorption resin and two fractions PSP-3 and PSP-5 were separated and identified by reversed phase high-performance liquid chromatography-tandem mass spectrometry(RP-HPLC-MS/MS). Peanut skin procyanidins(PSP) with a purity of over 98.0% and a recovery of 9.8% were obtained after the purification. PSP-3 was composed of 2 B-ty pe procyanidolic dimers and PSP-5 was composed of 4 A-type procyanidolic dimers.

Xylans are the major hemicelluloses in grasses, but their effects on biomass saccharification remain unclear. In this study, we examined the 79 representative Miscanthus accessions that displayed a diverse cell wall composition and varied biomass digestibility. Correlation analysis showed that hemicelluloses level has a strong positive effect on lignocellulose enzymatic digestion after NaOH or H2SO4 pretreatment. Characterization of the monosaccharide compositions in the KOH-extractable and non-KOH-extractable hemicelluloses indicated that arabinose substitution degree of xylan is the key factor that positively affects biomass saccharification. The xylose/arabinose ratio after individual enzyme digestion revealed that the arabinose in xylan is partially associated with cellulose in the amorphous regions, which negatively affects cellulose crystallinity for high biomass digestibility. The results provide insights into the mechanism of lignocellulose enzymatic digestion upon pretreatment, and also suggest a goal for the genetic modification of hemicelluloses towards the bioenergy crop breeding of Miscanthus and grasses.

Common understanding has been reached theoretically that biomass is a resource-rich and environmental-friendly energy In practice, however, the biomass industrial development in all countries is not yet satisfactory This paper makes an in-depth analysis of various factors restricting China's development of biomass industrialization from four aspects, i e technology, cost, market and policies, and proposes relevant recommendations for accelerating its further development