酵母提取物对葡萄糖发酵生产生物破乳菌Alcaligenes sp. S-XJ-1的影响

以从石油污染的土壤中筛选出1株生物破乳菌Alcaligenes sp.S-XJ-1为对象,考察了以葡萄糖为碳源时添加酵母提取物对生物破乳菌菌体性质、破乳性能以及菌体元素组成的影响.结果表明,酵母提取物的投加能够有效提高生物破乳菌产量,在酵母提取物浓度为5 g.L-1时,生物破乳菌产量达到3.0 g.L-1,此时葡萄糖利用率亦达到最大的58%.随着酵母提取物的投加浓度的增大,培养得到的菌体破乳性能提高,在投加浓度为10 g.L-1时,破乳率达到76%;而培养得到的菌体C/N有所降低,对其菌体表面蛋白进行提取测定发现菌体总蛋白含量升高,这与FTIR分析破乳菌菌体表面蛋白质类物质提高的结论一致.推测该生物破乳菌菌体蛋白含量的提高增强了菌体的破乳性能,菌体蛋白类物质是影响其破乳性能的关键组分之一.     

青稞B-hordein基因表达载体构建及对小麦的遗传转化

利用从具有特殊B-hordein亚基组成的青藏高原青稞材料中克隆的B-hordein编码基因(SL60)和小麦高分子量谷蛋白亚基胚乳特异表达启动子PGlu1Dx构建了真核表达载体pCB2007-SL60.通过农杆菌介导对普通小麦进行遗传转化,共获得227株再生植株,经PCR鉴定和转化片段测序验证,最终获得5株阳性植株.研究为进一步分析B-hordein基因在小麦背景中的遗传和表达,以及对小麦加工特性的影响奠定了基础.图5表2参21     

Fe3+对紫球藻生长及蛋白质和β-胡萝卜素含量的影响

为了考察Fe3+对紫球藻的生长及对可溶性蛋白和β-胡萝卜素合成的影响,分别在不同浓度的Fe3+下培养紫球藻.实验测定了紫球藻细胞的生长曲线,采用超声波破碎法破碎紫球藻细胞提取可溶性蛋白,考马斯亮蓝法测定可溶性蛋白含量,丙酮溶解提取β-胡萝卜素,分光光度计测定吸光值求β-胡萝卜素含量.实验结果表明,5×10-5mol/L的Fe3+对紫球藻的生长及可溶性蛋白的积累有较大作用,5×10-4mol/L的Fe3+对β-胡萝卜素的积累有较大作用.     

有关餐桌浪费的生态命题

餐桌浪费不只是个道德命题、更是一个生态命题,在建设节约型社会的今天,减少餐桌浪费,不但节约资源,也是减少环境压力的一个最便捷简单又行之有效的方法。来自中国农业大学食品科学与营养工程学院的调查数据显示:我国一年仅餐饮浪费的食物蛋白和脂肪就高达800万吨和300万吨,这相当于至少倒掉了两亿人一年的口粮。同样来自媒体的报道:全国     

Responses of wheat seedlings to cadmium, mercury and trichlorobenzene stresses

The molecular response of wheat (Triticum aestivum L.,cv.Yangmai 10) seedlings to heavy metal (Cd,Hg) and 1,2,4-trichlorobenzene (TCB) stresses were examined by two-dimensional gel electrophoresis,image analysis,and peptide mass fingerprinting.The results showed inhibitions of root and shoot growth by Cd,Hg and TCB.These stresses led to water deficit and lipid phosphorylation in the seedling which also promoted protein phophorylation in the leaves.Hg stress inhibited protein synthesis while Cd and TCB stresses induced or up-regulated more proteins in the leaves.Most of these induced proteins played important roles in the biochemical reactions involved in tolerance of wheat to Cd and TCB stresses.The primary functions of Cd- and TCB-induced proteins included methionine metabolism,Rubisco modification,protein phosphorylation regulation,protein configuration protection,H+ transmembrane transportation and also the synthesis of ethylene defense substances and cell wall compounds.     

高浓度豆制品废水预处理实验研究

对高浓度豆制品废水的预处理方法作了实验研究。采用调节等电点酸沉降的方法回收蛋白质,然后用聚合硫酸铁化学混凝处理上清液以降低COD的含量。实验证明了方法的可行性并得出了最佳实验条件。     

Differential response of multiple zebrafish hepatic F-box protein genes to 17α-ethinylestradiol treatment

Estrogens are accumulating in environment and their e ects on a variety of reproductive processes and tumorigenesis were reported by previous study, but the mechanism of estrogen promoting neoplasia was still not clear. F-box protein (FBP) is the component of E3 ubiquitin ligase which takes part in a variety of key biological processes. In this study, using mature male zebrafish, which are more sensitive to estrogen treatment, we examined influence of 17 -ethinylestradiol (EE2) exposure on the expression of a series of hepatic FBP genes, which take part in a variety of biological processes, including tumorigenesis. The influence of EE2 on the expression of hepatic mRNA concentrations of FBP genes were quantified based on the expression of the optimal internal control gene in male zebrafish after 7-day exposure to EE2, from a low-dose concentration (1 ng/L) to environmentally relevant concentrations (10, 100 ng/L). Our results showed that EE2 exposure reduced the expression of fbxl14a, fbxl14b, fbxo25 and -TRCP2b, but enchanced the expression of skp2. While the alterations in fbxl2, fbxw7, fbxo9, -TRCP2a, fbxl18 and fbxo45 mRNA levels were not observed after EE2 exposure. Thus, our results showed that the expression of hepatic FBP genes exhibited di erentially in male zebrafish exposed EE2. The changes of the expression level of FBP genes induced by EE2 may be an important clue to elucidate the correlations of estrogen and hepatic tumors.     

Effect of ultrasonic pretreatment on anaerobic digestion and its sludge dewaterability

To investigate the effect of ultrasonic pretreatment on anaerobic digestion and sludge dewaterability and further to probe into the influencing factors on sludge dewaterability, sludge flocs were stratified into four fractions: (1) slime; (2) loosely bound extracellular polymeric substances (LB-EPS); (3) tightly bound EPS (TB-EPS); and (4) EPS-free pellets. The results showed that ultrasonic pretreatment increased the anaerobic digestion efficiency by 7%–8%. Anaerobic digestion without ultrasonic pretreatment deteriorated the sludge dewaterability, with the capillary suction time (CST) increased from 1.42 to 47.3 (sec L)/g-TSS. The application of ultrasonic pretreatment firstly deteriorated the sludge dewaterability (normalized CST increased to 44.4 (sec L)/g-TSS), while subsequent anaerobic digestion offset this effect and ultimately decreased the normalized CST to 23.2 (sec L)/g-TSS. The dewaterability of unsonicated sludge correlated with protein (p = 0.003) and polysaccharide (p = 0.004) concentrations in the slime fraction, while that of sonicated sludge correlated with protein concentrations in the slime and LB-EPS fractions (p < 0.05). Fluorescent excitationemission matrix analysis showed that the fluorescence matters in the LB-EPS fraction significantly correlated with sludge dewaterability during anarobic digestion.     

污泥中一株产耐高温蛋白酶菌株的分离、鉴定及酶学特性

蛋白酶是水解蛋白质肽键的一类酶的总称,它可将蛋白质分解、转化为氨基酸,从而被动植物体直接吸收利用.基于此,以江苏省无锡市太湖新城污水处理厂的污泥为材料,通过观察水解圈大小和蛋白酶活性测定等方法,从中筛选出一株高产蛋白酶菌株TC16.同时,参照《伯杰氏细菌鉴定手册》和《常见细菌鉴定手册》,根据其形态学特征、生理生化特性,并结合16SrDNA序列的比对分析结果发现,该菌属于芽孢杆菌属菌株.对其酶学性质的研究发现,从该污泥中分离得到的菌株TC16分泌的胞外蛋白水解酶的活性最高可达621U·mL-1.研究表明,与其他芽孢杆菌属菌株相比,TC16菌株分泌的蛋白酶具有较高的酶活性,且具有较宽范围的pH和温度耐受性.     

穗花狐尾藻生长及酚类物质含量对光照强度的响应研究

沉水植物穗花狐尾藻(Myriophyllum spicatum)能产生对水华蓝藻生长有抑制效应的酚类活性物质。为了揭示光照强度对穗花狐尾藻的生长及其体内酚类物质含量的影响,文章研究了不同光照强度下穗花狐尾藻的生物量及其顶端组织与茎中的可溶性糖、可溶性蛋白、总酚的含量以及与酚类代谢相关酶——苯丙氨酸裂解酶(Phenylalanine ammonia-lyase,PAL)的活性,结果表明:穗花狐尾藻生物量随着光照强度的减弱而显著降低;高光照强度和中等光照强度下,顶端组织中可溶性蛋白、总酚含量和PAL酶活都明显高于茎中各指标;茎中的总酚含量、PAL酶活性在低光照强度下显著高于高光照强度和中等光照强度下。