电导微生物技术快速测定原料乳菌落总数的研究

从乳品电导率微生物学的角度研究了快速测定原料乳菌落总数的原理。向计算机(MALTHUS计算软件)中一一对应输入平皿菌落计数值的log值与检测时间，当输入50组以上数据时曲线自动生成。将电导测定方法与常规方法测定结果相比较，结果较理想。电导率微生物检测提供了传统微生物测试所不能比拟的优点。结果表明，该方法具有快速测定、方便、资料自动搜查、允许样品随时插入测试的优点，原料奶得以更快速的监测，适合用于原料乳的微生物指标的质量控制。     

THE EFFECT OF PITCHING YEAST AERATION ON THE PRODUCTION OF ACETIC ACID DURING FERMENTATIONS WITH BREWERS' YEAST: AN ENZYMATIC APPROACH

Aeration of pitching yeast signicantly increases the metabolism of acetate. This increase is particularly noticed at an enzymatic level, with special reference to the specific activity of the Fe⁺⁺⁺ linked pyruvate de-carboxylase which has been shown to be involved in the production of acetic acid. At the beginning of fermentations carried out with aerobic and anaerobic pitching yeasts, an increase in acetic acid production is observed, this is followed by reabsorption. Stabilisation in the concentration of acetic acid is observed until the end of fermentation. Initial and final concentrations of acetic acid obtained during fermentations were significantly higher in fermentations carried out with aerobic pitching yeasts than in fermentations carried out with anaerobic pitching yeasts.     

Cassava varietal screening for cooking quality: Relationship between dry matter,starch content,mealiness and certain microscopic observations of the raw and cooked tuber

Thirteen cassava (Manihot esculenta L Crantz) varieties from three successive annual harvests were screened for the mealiness of the cooked tuber, and the elasticity and smoothness of the pounded paste. Six were selected for further studies based on their mealiness and the starch and dry matter contents were determined. The diameter of the starch granules of the selected varieties and those of an irradiated M₁ V₂ population were measured. Microscopic examinations of the raw and cooked cells of the irradiated M₁ V₂ population were made. Correlations among all the parameters were studied. Varietal and seasonal differences in cooking quality were observed. There was no consistent relationship between mealiness of the boiled tuber and the elasticity and smoothness of the pounded paste. Varieties that were mealy were high in dry matter and starch content. The starch granules of mealy varieties were larger than those of nonmealy ones. There were no differences between mealy and non-mealy varieties in the arrangement of the cells or ‘cell condition’, of the raw tubers. However, the cells of the cooked tubers were held less cohesively, ie there was more ‘cell disorganisation’, in mealy varieties than in non-mealy ones.     

有氧运动联合补充D-核糖对小鼠抗疲劳和抗氧化的作用

研究有氧运动联合补充D-核糖对小鼠抗疲劳和抗氧化酶活性的影响,将小鼠分为安静对照组、有氧运动对照组、D-核糖对照组、D-核糖+有氧运动组。有氧运动组进行每周进行6 d的有氧跑台训练,D-核糖组每日每只灌胃2 mL核糖（300 mg/100 g）,通过12周的规律性有氧跑台训练后,建立小鼠负重游泳抗疲劳动物模型,分别记录小鼠负重力竭游泳时间,并测定小鼠体内肝糖原（hepaticr glycogen,HG）、肌糖原（muscle glycogen,MG）、血糖（blood glucose）、血尿素氮（blood urea nitrogen,BUN）、血乳酸( bloodlactic acid,BLA）、丙二醛（malondialdehyde,MDA）含量和总抗氧化能力（total antioxidant capacity,T-AOC）、谷胱甘肽过氧化物歧化酶（glutathione peroxide dismutase,GSH-Px）、超氧化物歧化酶（superoxide dismutase,SOD）、过氧化氢酶（catalase,CAT）等活力。结果表明,与安静对照组相比,有氧运动对照组、D-核糖对照组、D-核糖+有氧运动组小鼠负重游泳时间显著增加（P<0.05）,同时显著提高了小鼠体内肝糖原、肌糖原和血糖含量（P<0.05）,并降低了体内血尿素氮和血乳酸含量（P<0.05）。另外,其抗氧化活性结果表明,与安静对照组相比,有氧运动对照组、D-核糖对照组、D-核糖+有氧运动组的T-AOC均增强,SOD、CAT、GSH-Px活性也都显著升高（P<0.05）,MDA则显著降低（P<0.05）。说明长期规律的有氧运动联合补充D-核糖能显著提高机体内肝糖原、肌糖原、血糖含量和氧化应激能力,提高机体抗疲劳作用。     

On the gelation of mungbean starch and its composites

Light microscopy and the concentration dependence of the elastic modulus of mungbean starch (MB) gel indicate that the gelation of MB is mainly governed by a close‐packing mechanism. The mechanical property of the entire network is influenced by the strength of swollen amylose‐rich discrete gel particles rather than the surrounding matrix. However, when the physicochemical properties of the surrounding matrix is altered by the presence of flour fillers possessing lower gelatinisation temperature and enthalpy, both the stress‐related and strain‐related parameters of MB‐based mixed flour gels were reduced (P < 0.05). Addition of iota‐carrageenan (1.0% w/v), in both the absence and presence of calcium lactate (0–20 mm ), further reduced both the stress‐related and strain‐related parameters of the composite gels. This study shows the detrimental effect of the anionic hydrocolloids and divalent cation addition on the mechanical properties of a composite structure stabilised by close‐packing mechanism.     

基于ABAQUS的饲料料仓结构优化设计

饲料料仓是一种常用的饲料存储设备,一般采用钢板焊接及螺钉联接而成。它具有结构简单、制造方便、应用场合多的特点。料仓功用包括对散装物料的接收、贮存、卸出和料位指示等。饲料属于散体,会对所承载的料仓侧壁产生一定压力从而致其变形。为了避免应力过大导致事故,需要可靠的理论分析和正确的计算,并对其进行结构优化设计。     

采用好氧颗粒污泥工艺处理亚铵法制浆中段废水

针对亚铵法制浆中段废水的特点和好氧颗粒污泥工艺,提出了采用好氧颗粒污泥工艺处理亚铵法制浆废水,并对其进行可行性分析.分析表明,好氧颗粒污泥工艺在降解CODCr、去除NH3-N方面具有明显优势.文中还分析了高浓度硫酸盐、亚硫酸盐对该工艺的抑制作用,并提出了消除抑制的方法.     

染料废水处理技术的试验研究

通过对国内染料废水处理技术的分析研究，选择和确定采用以生化处理为主体的工艺路线，试图通过改善生化的条件并通过必要的措施改善污水的可生化性。试验是在实验室试验基础上进行探索性放大试验，分为污泥培养驯化、条件试验和验证试验三个阶段，通过试验确定主要工艺参数，改善污水的生化性能，提高污染物去除率，解决废水的生化处理技术及商含钙废水在生化过程中和沉积和绪垢问蘧。     

Modeling and simulation of the formation and utilization of microbial products in aerobic granular sludge

A mathematical model is established to simulate the formation of extracellular polymeric substances (EPS), soluble microbial products (SMP), and internal storage products (X_STO) in aerobic granular sludge. The sensitivity of these microbial products concentrations toward the key model parameters is analyzed. Independent experiments are conducted to find required parameter values and to test its predictive ability. The model is evaluated by using one‐cycle operating experimental results of a lab‐scale aerobic granule‐based sequencing batch reactor (SBR) and batch experimental results. Results show that the model is able to describe the microbial product dynamics in aerobic granules and provide further insights into a granule‐based SBR. The effect of the initial substrate and biomass concentrations on the formation of microbial products in aerobic granular sludge can therefore be analyzed by model simulation. A higher substrate concentration results in a greater concentration of EPS, SMP, and X_STO. An accumulation of biomass in the bioreactor leads to an increased production rate of EPS, SMP, and X_STO. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

The relationship of silage temperature with the microbiological status of the face of corn silage bunkers

A method is proposed to quantify aerobic deterioration of corn silage forage quality as related to the temperature of silage mass in the bunker. Aerobic deterioration, apart from causing nutritional value losses, affects the hygienic quality of silages through the accumulation of pathogenic organisms and their toxins. A survey was carried out in northern Italy that involved a detailed examination of silage bunker from each of 54 dairy farms. Samples from the core, the peripheral areas within 1 m from the silo walls, and the molded spots, when present, were collected. The sample and silage temperatures across the working face were measured at depths of 200 mm at 11 locations and at 7 elevations. The temperature of the central zone of the silo was defined as the reference temperature (T_ref40). The difference between the temperature of the silage sample and the T_ref40 was used as a heating index associated with aerobic deterioration (dT_ref40). The working face area with visible molds was measured. The samples were analyzed for DM content; pH; water activity; nitrates; lactic, acetic, and butyric acids; and microbiological count of yeasts, molds, and clostridia spores. The core samples always showed a pH below 4.0 and a dT_ref40 below 2°C, whereas the silages from the peripheral areas were split into 2 groups, one that had a pH lower than 4 and a dT_ref40 lower than 3.5°C (53%) and one that had a pH higher than 4 and a dT_ref40 higher than 5°C (47%). Most of the silages from the peripheral areas (94%) and all the silages from the moldy spots that have a dT_ref40 above 5°C had a pH higher than 4.5. Furthermore, a positive dT_ref40 higher than 5°C corresponds to a higher yeast count than 5 log cfu/g in most of the silages from the peripheral areas (93% of samples) and in almost all the silages from the molded spots. The evaluation of the extension of the visible molded areas combined with temperature measurement at 200 mm behind the feed-out face could offer a good indication of the health status of silage during consumption. Furthermore, this method could be useful to detect early stages of the aerobic deterioration process and to improve silage management.