Molecular detection of the Australian grapevine yellows phytoplasma and comparison with grapevine yellows phytoplasmas from Italy

A diagnostic test using the polymerase chain reaction is described for the detection of phytoplasma DNA in grapevines collected from South Australia and Victoria. Grapevines with Australian grapevine yellows disease tested positively for a phytoplasma but those with 'restricted spring growth syndrome' (formerly called 'grapevine decline') tested negatively. Restriction fragment length polymorphism analyses were done to determine the relationships between phytoplasmas of the Australian grapevine yellows and of representatives from both the aster yellows group (which includes phytoplasmas of grapevine yellows from Italy) and the elm yellows group (which includes phytoplasmas of flavescence dorée). Results showed that Australian grapevine yellows is associated with a unique phytoplasma that is more closely related to the phytoplasmas of the aster yellows group than to those of the elm yellows group.     

鱼皮质量分数对热水浸提明胶的性质及其成膜性能的影响

以罗非鱼皮为原料,考察了热水浸提液中鱼皮质量分数对明胶性质及其成膜性能的影响。结果发现,随着鱼皮质量分数的提高,明胶的黏度和凝胶强度都呈现先上升后下降的趋势。当利用明胶制备成蛋白膜时,膜的机械性能也呈现相同的变化趋势。当热水浸提液中的鱼皮质量分数为10.0%时,提取的明胶其凝胶强度为281g,制备的明胶蛋白膜其抗拉伸强度为60MPa。然而,明胶的氨基酸组成和蛋白组分都没有发现明显的差异。根据差示扫描量热分析和圆二色谱分析的结果,表明利用鱼皮质量分数为10.0%浸提时,提取的明胶其无规则卷曲程度相对较小,结果形成的明胶蛋白膜的热稳定性最高。      

Effects of hot‐water treatment,post‐hot‐water‐treatment cooling and cold storage on the viability of dormant grafted grapevines under field conditions

Background and Aims: Hot‐water treatment (HWT) is an effective control method for black‐foot and Petri disease, in grapevine propagating material. However, plant hydration and cold storage have emerged as critical factors in the production of quality planting material. The effects of HWT protocols on the performance of dormant plants ready to be sold to producers under field conditions were investigated. Methods and Results: The effects of HWT at 53°C for 30 min, cooling (post‐HWT cooling or no post‐HWT cooling) and cold storage (0, 1, 2 and 4 weeks) on sprouting, and shoot length and weight in dormant grafted plants (Tempranillo cultivar grafted onto 110 Richter rootstock) were evaluated. Eight bundles of ten cuttings were treated for each factor combination, and eight additional bundles of ten untreated cuttings were prepared as controls (no HWT). Dormant grafted plants were immediately planted in two field sites in March 2010. The number of plants that emerged from dormancy was counted in July 2010. In January 2011, shoot length and fresh weight were evaluated. Although significant, the percentages of plants emerging from dormancy among treatments were relatively small. A significant reduction was observed in shoot length and weight for all treatments compared with the control, particularly in all variables for non‐hydrated hot‐water‐treated cuttings kept in cold storage for 4 weeks immediately after HWT. Conclusions: The findings obtained in this study indicate that long‐term cold storage could be detrimental to planting material, especially when plants have not been previously hydrated following HWT. Significance of the Study: This study represents the first approach for evaluation of different HWT protocols under field conditions. It improves the knowledge of the different steps used in the HWT process and provides valuable information about the most reliable protocol that can be used successfully in a commercial situation.     

家具生产中木质废料的来源、控制与处理

分析了家具制造企业原料输入和废料产生情况,针对家具生产过程木质废料的产生情况和废料形式进行了剖析,结合生产实际提出了家具生产木质废料的控制与处理措施。     

Trichloroethylene and tetrachloroethylene elimination from the air by means of a hybrid bioreactor with immobilized biomass

Two-phase bioreactors consisting of bacterial consortium in suspension and sorbents with immobilized biomass were used to treat waste air containing chlorinated ethenes, trichloroethylene (TCE) and tetrachloroethylene (PCE). Synthetic municipal sewage was used as the medium for bacterial growth. The system was operated with loadings in the range 1.48-4.76 gm(-3)h(-1) for TCE and 1.49-5.96 gm(-3)h(-1) for PCE. The efficiency of contaminant elimination was 55-86% in the bioreactor with wood chips and 33-89% in the bioreactor filled with zeolite. The best results were observed 1 week after the pollutant loading was increased. However, in these conditions, the stability of the process was not achieved. In the next 7 days the effectiveness of the system decreased. Contaminant removal efficiency, enzymatic activity and the biomass content were all diminished. The system was working without being supplied with additional hydrocarbons as the growth-supporting substrates. It is assumed that ammonia produced during the transformation of wastewater components induced enzymes for the cometabolic degradation of TCE and PCE. However, the evaluation of nitrogen compound transformations in the system is difficult due to the sorption on carriers and the combined processes of nitrification and the aerobic denitrification. An applied method of air treatment is advantageous from both economic and environmental point of views.     

超声波辅助碱-酸法提取蔗渣纤维素的研究

以蔗渣为原料,采用超声波、碱性过氧化氢、乙酸溶液依次处理蔗渣获得蔗渣纤维素,通过正交试验确定优化提取工艺,借助傅里叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)及热重分析仪(TGA)对各处理阶段试样进行表征。结果表明,当超声波处理时间为15min,液固比为30∶1、NaOH质量分数为4%、H2O2体积分数为0.8%、温度为80℃、碱处理5h,酸处理4h时,提取的纤维素纯度最高为92.8%。提纯后的纤维素仍保持纤维素Ⅰ型结晶结构,结晶度为68.7%;其最大热解速率时的温度为353℃。     

Production of oligosaccharides from coconut meal by subcritical water treatment

Coconut meal, a by‐product from coconut milk production, was hydrolysed via subcritical water treatment at various maximum temperatures in the range of 100–300 °C using a batch‐type vessel under nonisothermal conditions. The effect of the treatment temperature and time was evaluated using the severity factor (R₀) as a parameter. The highest yield of mono‐ and oligosaccharides (28.3 g/100 g dry coconut meal) was obtained at lnR₀ = 10.4 (maximum temperature of 250 °C within the treatment time of 14 min). At higher temperature, degradation of the saccharides was observed and a large quantity of 5‐hydroxymethyl‐2‐furaldehyde was detected. The hydrolysates contained mannose, glucose and manno‐oligosaccharides with various degrees of polymerisation. The yield and ratio of saccharide components were affected by variation of the ratio of coconut meal to water used in the subcritical water treatment.     

ACC oxidase activation by cold storage on ‘Passe-Crassane’ pears: effect of calcium treatment

Ethylene biosynthesis and respiration in untreated and in calcium-treated Passe-Crassane pear fruits during cold storage and during ripening at 20°C after removal from storage at 2°C was studied. Results suggest that the increase in ACC oxidase activity along with free-ACC availability for enzyme action is the most important limiting factor in the capacity of these fruits to produce ethylene and to ripen. A chilling period of at least 30 days was shown to be required for inducing the climacteric increase in ethylene biosynthesis. Calcium treatment partially prevented ethylene production and retarded the onset of the climacteric process in Passe-Crassane fruits. The role that calcium plays in preventing cellular wall and membrane degradation is probably responsible for this delaying effect on the ripening process of this pear cultivar. © 1998 SCI.     

物理处理玉米皮渣对酶法提取阿魏酰低聚糖的影响

以玉米皮渣为原料,考察物理处理对其水解获得阿魏酰低聚糖产量的影响。通过测定不同方法处理前后玉米皮渣细胞壁组成和其结构变化及阿魏酰低聚糖(Feruloyl oligosaccharides,FOs)产量关系,探讨物理处理影响FOs生成的原因。结果表明:高压蒸煮处理使酶解玉米皮渣生成FOs产量提高了1.5倍,原因是高压蒸煮改变了玉米皮渣细胞壁的组成,其中纤维素和果胶质得以释放,增加了纤维素酶和木聚糖酶与底物的接触几率;微波和膨化处理均使玉米皮结构裂解,FOs产量无显著变化。      

碱液处理花生脱除花生油中黄曲霉毒素B1的研究

用碱液处理花生,检测压榨花生油中的黄曲霉毒素B_1(AFB_1)的含量及花生油质量指标。研究表明:碱液处理花生对脱除花生油中黄曲霉毒素B_1具有良好的效果。采用碱液pH 13. 40、碱液加入量10%的条件处理四级花生15 min,压榨花生油中AFB_1脱除率达93. 3%,采用p H 13. 44、碱液加入量7. 5%的条件处理三级花生25 min,压榨花生油中AFB_1脱除率达98. 0%。碱液处理对花生油的酸价有一定影响但在标准规定范围内,对过氧化值、碘值及脂肪酸组成无确定影响关系。     

Stability of oil‐in‐water emulsions as influenced by thermal treatment of whey protein dispersions or emulsions

Properties of whey protein concentrate stabilised emulsions were modified by protein and emulsion heat treatment (60–90 °C). All liquid emulsions were flocculated and the particle sizes showed bimodal size distributions. The state and surface properties of proteins and coexisting protein/aggregates in the system strongly determined the stability of heat‐modified whey protein concentrate stabilised emulsions. The whey protein particles of 122–342 nm that formed on protein heating enhanced the stability of highly concentrated emulsions. These particles stabilised protein‐heated emulsions in the way that is typical for Pickering emulsions. The emulsions heated at 80 and 90 °C gelled due to the aggregation of the protein‐coated oil droplets.     

Extending shelf-life of persimmon (<Emphasis Type="Italic">Diospyros kaki</Emphasis> L.) fruit by hot air treatment

‘Qiandaowuhe’ persimmon fruits (Diospyros kaki L.) were stored at 20 °C after exposed to 20 °C (control), 44 °C (T ₄₄), 48 °C (T ₄₈) or 52 °C (T ₅₂) hot air for 3 h, respectively. Firmness, weight loss, peel color, total carotenoids content, soluble solids content (SSC), titratable acidity (TA), respiration, and ethylene production and cell wall hydrolysis enzymes activities were monitored to determine the efficacy of hot air treatment in delaying persimmon fruit ripening. Results showed that ‘Qiandaowuhe’ persimmon fruit displayed a typical climacteric pattern of respiration and ethylene production. Peak of CO₂ and ethylene production was observed after 4 days. Fruit softening was accompanied by a progressive increase in weight loss, total carotenoids content and decrease in h°. The activities of pectinmethylesterase (PME) and polygalacturonase (PG) sharply increased and reached maximal values after 4 and 6 days, respectively. Hot air treatment significantly delayed the onset of climacteric ethylene production, respiration, PME and PG activities in persimmon fruit. Moreover, it also significantly retarded the increase in carotenoids content and SSC, while decreased the firmness, h°, and TA. The hot air treatment promoted fruit weight loss. The shelf-life of persimmon ripening increased 4 days by T ₄₄, and 6 days by T ₄₈ or T ₅₂. Results suggest that hot air treatments can greatly extend the postharvest life of ‘Qiandaowuhe’ persimmon fruit.