SBR活性污泥法处理味精废水的工艺研究

本文对SBR(序列间歇式反应器)活性污泥法处理味精废水的工艺作了初步探讨。提出了必要的设计参数和运行要点。在SBR活性污泥法中控制充水时间和曝气方式是防止反应受抑制,最大限度地提高反应速度,缩短反应周期的重要手段。试验提出SBR活性污泥法处理味精废水的最佳工艺参数;充水时间:2h,同时进行搅拌保持缺氧状态;曝气方式;限制曝气;污泥负荷:0.2～0.4kgCODcr/kgMLSS·d(混合液悬浮固体浓度);溶解氧:搅拌时0.3mg/l,曝气时2.3mg/l;水温:(23±2)℃。在此运行条件下,当进水CODcr为2750mg/l、NH_3-N为275mg/1时,出水CODcr及NH_3-N均能达到轻工部颁发的味精工业废水污染物排放标准。     

压力曝气生物反应器处理废水的研究

压力曝气反应器采用压力曝气提高混合液的溶解氧及有机物降解速度,曝气压力为0.05~0.25 MPa;密闭塔式结构,设备最佳高度与直径比为3∶1.以乙醛废水为试验介质,在曝气压力分别为0.10,0.15,0.20 MPa时,反应器中混合液溶解氧(DO)质量浓度达到5.0,7.5,10.0 mg.L-1;有机物降解速度(以化学耗氧量COD计)分别为5.80,7.20和9.50 kg.m-3.d-1,为常压曝气的2.5~4.0倍.在曝气压力为0.15~0.20 MPa时,污泥表观产率为常压曝气的1/2~1/3左右,混合液微生物脱氢酶活性指示物(TF)质量浓度达到80μg.mL-1.应用该反应器处理味精废水,污泥龄为5~8 d,污泥质量浓度为3 500~5 000 mg.L-1,水力停留时间为7 h,曝气压力0.10 MPa,曝气量为处理水量的20~30倍,COD去除率达到97.7%,NH3-N去除率达到96.0%,处理出水达到国家一级排放标准.     

Genomic structure of metabotropic glutamate receptor 7 and comparison of genomic structures of extracellular domains of mGluR family

Metabotropic glutamate receptor 7, coupled with a chemical neurotransmitter L-glutamate, plays an important role in the development of many psychiatric and neurological disorders. To study the biological and genetic mechanism of the mGluR7-related diseases, a physical map covering the full-length mGluR7 genomic sequence has been constructed through seed clone screening and fingerprinting database searching. These BAC clones in the physical map have been sequenced with shotgun strategy and assembled by Phred-Phrap-Consed software; the error rate of the final genomic sequence is less than 0.01%. mGluR7 spans 880 kb genomic region, the GC content and repeat content of mGluR7 genomic sequence are 38% and 37.5% respectively. mGluR7 has a typical “house-keeping” promoter and consists of 11 exons, with introns ranging from 6 kb to 285 kb. mGhiR7a and mGluR7b are two known alternatively splicing variants. Comparing the genomic structures of extracellular domains of mGluR family, their genomic structures can be subdivided into three groups, which are consistent with that of proteins. Although the genomic organization of mGluR7’s group is conserved, the majority of introns in the extracellular segments vary dramatically. It is an obvious trend of the increasing intron size inverse proportion to phylogenetic time. Variation of genomic structure is higher than that of protein, which is attributed to the species characteristic regulation of gene expression.     

厌氧光合系统中光合细菌的分离和特性

从厌氧消化反应器中分离出光合细菌．根据菌体形态、光合色素的吸收光谱及生理生化特征,鉴定为荚膜红假单胞菌（ＲｈｏｄｏｐｓｅｕｄｏｍｏｎａｓＣａｐｓｕｌａｔａ）和浑球红假单胞菌（ＲｈｏｄｏｂａｃｔｅｒＳｐｈｅｒｏｉｄｅｓ）．这２种光合细菌能够利用多种小分子有机酸,耐受高浓度硫酸盐,具有较强的降解味精废水中ＣＯＤ物质的生物活性．     

A convulsant, 3-mercaptopropionic acid,decreases the level of GABA and GAD in rat pancreatic islets and brain

To investigate the properties of the gamma-aminobutyric acid (GABA) synthesizing enzyme, glutamate decarboxylase (GAD), in the brain and the pancreatic islets of the rat, GABA concentration in the brain and the pancreatic islets was measured after intraperitoneal administration of 3-mercaptopropionic acid (3-MP) at 25 mg/kg. 60 min after the administration of 3-MP, GABA concentration in the hypothalamus, the superior colliculus and the hippocampus of the brain decreased by 20–30% and in the pancreatic islets by 35%. The concentration in the pancreatic acini did not change. Western blotting showed that GAD activity in the pancreatic islets decreased after administration of 3-MP compared to the control. The activity of GAD in the pancreatic islets as well as brain can be modified by a convulsant, in this case 3-MP. These results suggest the properties of GAD may be similar in the pancreatic islets and brain.     

谷氨酸生物传感器的研制

采用海藻酸钙凝胶包埋法及海藻酸钙凝胶包埋与戊二醛化学交联相结合的固定化方法，制备了固定化谷氨酸脱羧酶膜，与ＣＯ２气敏电极偶联制成谷氨酸生物传感器。经测试，对谷氨酸的线性响应范围为（１．０×１０（－２）～２．０×１０（－４））ｍｏｌ／Ｌ，斜率为５５．７ｍＶ，检测下限为２．３×１０（－４）ｍｏｌ／Ｌ，稳态响应时间为（９～１５）ｍｉｎ。用包埋与交联相结合制得的传感器，其稳定性优于仅用包埋法制得的传感器。     

谷氨酸脱氢酶(GDH)的性质

考察了GDH催化的最适条件:40℃,pH8.5,磷酸盐缓冲液离子强度为0.25mol/L.酶活性稳定的pH范围为5.5～9.0.甘油对GDH的热变性有明显的保护作用.     

固定化谷氨酸棒杆菌T6-13细胞生产L-谷氨酸

本文比较了海藻酸钙、明胶-戊二醛、聚丙烯酰胺和琼脂包埋法制备固定化细胞的方法。前者较后几种有较大的优越性,是一种较为理想的固定化方法.分析了海藻酸钙法国定化细胞各主要因素对酶活性的影响,确定出制备固定化细胞的最佳条件.观察凝胶珠中细胞及酶活性的变化表明,细胞在凝胶珠中生长良好,有利于谷氨酸生产.固定化细胞发酵谷氨酸的最适 pH 为7. 0～7. 5,最适温度32℃,最适转速140rpm.每批发酵96小时,糖利用率为98%,产酸量达20g/L,比常规游离细胞增加15%.     

味精废水中污染物的形态分析及处理研究

测定了味精废水的各项水质指标:pH值、色度、浊度、悬浮物、总蒸发残渣、氯化物、硫酸根、COD值、亚硝酸盐氮、硝酸盐氮、氨氮、无机氮、有机氮及总氮等.再对水样进行理化预处理,使处理后水样符合生物处理所需水样的进水水质指标,主要包括混凝处理实验、吸附处理实验、壳聚糖处理味精废水等.