To ensure the regular growth of ancient Cinnamomum camphora(L.)J.Prest of which the growth environment had changed,the growth environment and soil basic physical and chemical properties of C.camphora at lakeside of West Lake in Hangzhou was investigated and tested.The results showed that most C.camphora in the scenic spots were at health status.Factors including age,site conditions and conservation level were important to the growth of ancient C.camphora so that garden management department should pay attention to daily monitoring of the ancient and famous trees as well as rejuvenation protection according to growth status of ancient C.camphora.

Escherichia coli NZN111 is a double mutant with lactate dehydrogenase (ldhA) and pyruvate formate-lyase (pflB) inactivated. Under anaerobic conditions, disequilibrium of coenzyme NADH and NAD+ causes Escherichia coli NZN111 losing the glucose utilizing capability. In this study, we constructed a recombinant strain E. coli NZN111/pTrc99a-mdh and overexpressed the mdh gene with 0.3 mmol/L of IPTG under anaerobic fermentation condition in sealed bottles. The specific malate dehydrogenase (MDH) activity in the recombinant strain was 14.8-fold higher than that in E. coli NZN111. The NADH/ NAD+ ratio decreased from 0.64 to 0.26 and the concentration of NAD+ and NADH increased 1.5-fold and 0.2-fold respectively. Under anaerobic conditions, the recombinant strain possessed the capability of growth and glucose absorption. We took dual-phase fermentation for succinate production. After the dry cell weight (DCW) reached 6.4 g/L under aerobic conditions, the cell culture was changed to anaerobic conditions. After 15 h, 14.75 g/L glucose was consumed and succinic acid reached 15.18 g/L. The yield of succinic acid was 1.03 g/g Glu and the productivity of succinic acid was 1.012 g/(L x h).

Succinic acid was produced with cassava starch,and simultaneous saccharification fermentation(SSF) and separated hydrolysis and fermentation(SHF) were compared.The results showed that SSF was more economical than SHF.Then the conditions of SSF were optimized by flask fermentation.The optimized conditions were obtained as follows: dosage of saccharification enzyme 1000U/g,fermentation temperature 37℃ and substrate concentration 60g/L.When SSF was carried out in 7L fermenter for 45h under the optimum conditions,succinic acid and acetic acid concentration reached 61.2g/L and 4.66g/L,respectivety.Succinic acid productivity was 1.36g/(L·h) and the conversion rate of cassava to succinic acid reached 89%.

Escherichia coli strain NZN111 is a promising candidate for the fermentative production of succinate. However, because lactate dehydrogenase and pyruvate formate lyase were inactivated in NZN111, this strain had an unbalanced NADH/NAD+ ratio and could not use glucose under anaerobic conditions. In this study, a recombinant strain E. coli NZN111/pTrc99a-pncB was constructed to overexpress the nicotinic acid phosphoribosyl transferase gene (pncB). Under anaerobic conditions with the addition of 0.5 mmol/L nicotinic acid and 0.3 mmol/L isopropyl beta-D-thiogalactopyranoside (IPTG), the specific nicotinic acid phosphoribosyl transferase (NAPRTase, EC 2.4.2.11) activity in the recombinant strain was 11-fold higher than that in E. coli NZN111, the concentration of NAD(H) was increased by 3.85-fold, especially the concentration of NAD+ was increased by 5.17-fold and NADH/NAD+ was decreased from 0.640 to 0.125. The recombinant strain regained the capability of growth and glucose utilization under anaerobic conditions.

The isolation and purification of sucrose phosphorylase from Leuconostoc mesenteroides G123 anaerobic fermentation was investigated. The cell recovered from the broth was disrupted by sonication to get crude enzyme solution.The sucrose phosphorylase was purified by precipitation with ammonium sulfate and ion exchange chromatography,leading to 15-fold purification with 31.7%recovery rate.The product showed eletrophoretic homogeneity,as identified by sodium dodecyl sulphate-polyacrylamide gel electrophoresis(SDS-PAGE),and the specific activity of the purified sucrose phosphorylase reached 115.3 U/mg.SDS-PAGE analysis indicated that the relative molecular mass of the protein was about 55.7 kD.The enzyme was stable in the pH range of 5.5-8.0.The pH stability of the sucrose phosphorylase G123 was larger than the enzyme of Leuconostoc mesenteroides B-1149 reported by Jin-Ha Lee.After kept in the condition temperature 37℃,sucrose phosphorylase G123 activity was hardly declined.In the reaction of synthesis a-arbutin by purified sucrose phosphorylase,the sucrose was servered as glucosyl donor and the hydroquinone as acceptor.The optimal condition of synthesis of a-arbutin by sucrose phosphorylase G123 was determined 50%sucrose,5%hydroquinone,pH7.5,37℃,23 U/mL sucrose phosphorylase,and the reaction time was 12 hours,under which the transfer ratio of hydroquinone reached 16.3%,and the yield ofα-arbutin was about 20 g/L.

Succinic acid production by repeated batch fermentation based on high density culture was studied.The result showed that E.coli could convert glucose to succinic acid in aqueous solution of glucose and a neutralizer.When cell density increased approximately to 28 g·L-1(DCW),the aerobically grown cells were directly brought into anaerobic conditions.Glucose concentration was maintained at about 10 g·L-1 with constant flow feeding.Cells were recycled from final fermentation broth for the next batch of repeated fermentation when the last fermentation was stopped at 30 h.After two-stage fermentation and two cycles of cell reincubation,the concentration of succinic acid was 95.1 g·L-1,79.7 g·L-1 and 64.4 g·L-1 respectively.The average succinic acid yield and productivity were 72.5% and 1.93 g·L-1·h-1 respectively,with an increase of 29.5% and 25.9%,compared with those in the two-stage fermentation.

通过对1起BOC(叔丁氧羰基)生产中误操作造成的氯化氢泄漏事故的后果模拟分析,说明扩散模型与后果伤害模型对预测事故伤亡后果和人员应急响应策略选择的作用.首先确定事故中氯化氢的泄漏量和泄漏方式,采用高斯烟团模型模拟扩散过程,利用室内外换气公式,得出室内外氯化氢气体质量浓度随时间变化的关系,然后结合概率函数法得出室内外暴露剂量以及概率变量随时间变化的关系.模拟结果表明,室内外的概率变量都小于-7,因此人员死亡概率为0,与事故实际造成的后果基本相符.因此,选择相应的扩散模型与后果伤害模型对毒气泄漏事故进行后果模拟分析,能定量确定泄漏事故对特定范围内造成的危险程度,预测事故伤亡后果.

Undaria pinnatifida Suringar contains rich protein and polysaccharides,which have significantly physiological functions in reducing blood fat,improving immunity,antiviral and antineoplastic etc.Using Undaria pinnatifida Suringar as main raw material,a fermented beverage was prepared after yeast fermentation,formulation,sterilization and filling.The results indicated that the optimum yeast fermentation conditions were as follows:innoculum of yeast 8%,fermentation temperature 30℃,and fermentation time 24h.And the optimal formula of Undaria pinnatifida Suringar fermentation beverage was 50% of fermented juice,sucrose 6%,sodium cyclamate 0.05% and sodium benzoate 0.05%.

Undaria pinnatifida Suringar contains rich nutrient content,which have important action such as reducing blood fat,antioxidation and antineoplastic.It is a food which has good nutrition and health function.Because of the fishy smell,it is to limit in the function food and medicine.Yeast fermentation was determined as the best way to eliminating fishiness by comparing the results of glucose,β-cyclodextrine,active carbon and yeast fermentation.The results of the test showed that the formula was the best one,which 0.3% yeast and 3% sucrose at 30℃ for 30 min,there were little smell left.After the experiments,the extract fluid is delicious from the smell of seafood.It is a basis to apply in the exploit of Undaria pinnatif ida Suringar.

Escherichia coli AFP111, a pflB, ldhA, ptsG triple mutant of E. coli W1485, can be recovered for additional succinate production in fresh medium after two-stage fermentation (an aerobic growth stage followed by an anaerobic production stage). However, the specific productivity is lower than that of two-stage fermentation. In this study, three strategies were compared for reusing the cells. It was found when cells were aerobically cultivated at the end of two-stage fermentation without supplementing any carbon source, metabolites (mainly succinate and acetate) could be consumed. As a result, enzyme activities involved in the reductive arm of tricarboxylic acid cycle and the glyoxylate shunt were enhanced, yielding a succinate specific productivity above \( 1 2 5\;{\text{mg}}\;{\text{g}}_{\rm DCW}^{ - 1} \,{\text{h}}^{ - 1} \) and a mass yield above 0.90 g g−1 in the subsequent anaerobic fermentation. In addition, the intracellular NADH of cells subjected to aerobic cultivation with metabolites increased by more than 3.6 times and the ratio of NADH to NAD+ increased from 0.4 to 1.3, which were both favorable for driving the TCA branch to succinate.

The possibility of reusing Escherichia coli cells from the broth for succinic acid production was investigated. Using succinic acid yield and productivity as criterion, we investigated the effects of cell concentration, initial glucose concentration, different neutralizers on the bioconversion. The results revealed that E. coli could convert glucose to succinic acid in a water solution of glucose and a neutralizer. According to the results, the optimal condition was as follows: the cell concentration was 50 (OD600), glucose concentration was 40 g/L and neutralizer was MgCO3. Under the optimum conditions, we carried out the consecutive batch bioconversion in 7 L fermenter. Succinic acid yield reached 91% with the productivity of 3.22 g/(L x h) for the first conversion. For the second conversion, succinic acid yield reached 86% with productivity of 2.04 g/(L x h). Furthermore, we achieved a high mass yield above 83% with the productivity of 1.82 g/(L x h) for the third bioconversion.

Escherichia coli AFP111 cells recovered from spent two-stage fermentation broth were investigated for additional production of succinic acid under anaerobic conditions. Recovered cells produced succinic acid in an aqueous environment with no nutrient supplementation except for glucose and MgCO(3). In addition, initial glucose concentration and cell density had a significant influence on succinic acid mass yield and productivity. Although the final concentration of succinic acid from recovered cells was lower than from two-stage fermentation, an average succinic acid mass yield of 0.85 g/g was achieved with an average productivity of 1.81 g/l h after three rounds of recycling, which was comparable to two-stage fermentation. These results suggested that recovered cells might be reused for the efficient production of succinic acid.

We studied the effect of aerobic glucose-feeding strategies,which controlled the cell growth on the anaerobic fermentation.The optimum transition time was the one when aerobically grown at special growth rate of 0.07 h-1,at OD600 = 30.E.coli AFP111 showed that the optimal fermenta-tion capability with a final succinic acid concentration of 94.2 g/L,a mass yield of 105% and productivity of 1.76 g/(L.h) during the anaerobic stage.

ABSTRACT Aerobic growth conditions significantly influenced anaerobic succinate production in two-stage fermentation by Escherichia coli AFP111 with knockouts in rpoS, pflAB, ldhA, and ptsG genes. At a low cell growth rate limited by glucose, enzymes involved in the reductive arm of the tricarboxylic acid cycle and the glyoxylate shunt showed elevated activities, providing AFP111 with intracellular redox balance and increased succinic acid yield and productivity.

Transgenic technology in turfgrass breeding has been widely used as breeding transgenic one of the major means.This paper outlines the transgenic commonly used method,transgenic goal,the detection of transgenic plants main methods and steps,and transgenic turfgrass now facing major problems.

通过对非转基因草地早熟禾(Poa pratensis L.)、转CMO-BADH双基因草地早熟禾、转CMO基因草地早熟禾进行不同浓度的NaCl胁迫试验,测定其细胞膜的透性,丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD) 活性、氧化氢酶(CAT)活性,评定各株系耐盐能力的强弱,同时还验证并比较了CMO-BADH双基因和CMO基因的耐盐性功能,为耐盐新品种的选育提供了理论依据.结果表明: 所有株系的相对电导率、MDA含量均随盐浓度增加而增大,在NaCl胁迫下相对电导率和MDA含量的大小顺序为:非转基因株系＞转CMO基因株系＞转CMO-BADH双基因株系;在NaCl的胁迫下,各个株系的SOD活性、POD活性、CAT活性都有明显的提高,此3种指标的大小顺序为:转CMO-BADH双基因株系＞转CMO基因株系＞非转基因株系;综合考虑各个指标,各株系耐盐性强弱顺序为:转CMO-BADH双基因株系＞转CMO基因株系＞非转基因株系.

一种新型促渗透剂PAG-OA（聚氧烯油酸二醇）I 5,甲苯、气流干燥及吐温100等,对酿酒酵母进行细胞渗透性增强处理,考察了酿酒酵母的促渗透性对三磷酸腺苷生产的影响。结果表明,与其他促渗透方式相比,I 5对酿酒酵母三磷酸腺苷的产量有很大的提高。加入0.022 mol/L腺苷,三磷酸腺苷得率为0.038 mol/L,转化率98%;三磷酸腺苷合成时间缩短为1.5 h。经促渗透化处理的酿酒酵母细胞能很好的释放胞内代谢的极性物质;其三磷酸腺苷生产活性大幅度提高。