以青砖茶为原料的果茶饮料制备

以青砖茶、新鲜苹果汁、西瓜汁和菠萝汁为主要原料进行果茶饮料的研制,采用单因素试验及正交分析试验对果茶饮料的配方进行工艺优化,以感官评价和吸光值为评定指标,确定果茶饮料的最佳配方。结果表明,体积比分别为8∶2的茶汤与苹果汁的混合汁、5∶5的茶汤与西瓜汁的混合汁和3∶7的茶汤与菠萝汁的混合汁混匀调配出的茶饮料的口感最佳,色泽清透,且香气较佳。本研究为黑茶果茶饮料的研 制提供了理论依据。     

酿酒酵母酚类抑制物耐受性脂质组学研究

通过脂质组学分析方法从细胞膜磷脂分布方面探究适应进化酿酒酵母酚酸耐受性机制。主要利用高效液相色谱-质谱(LC-MS)对酚酸胁迫下适应进化菌株和原始菌株脂质成分检测并进行统计学比较分析。检测出565种脂质代谢物,包含细胞膜磷脂185种。相比初始菌株,适应进化菌株细胞膜中磷脂酰胆碱(PC)、磷脂酰乙醇胺(PE)和磷脂酰肌醇(PI)类磷脂分子相对含量增加,含有长链(C32-C36)和双不饱和脂酰链的磷脂分子含量增加。统计学分析表明显著性差异磷脂分子主要为含有长链不饱和脂酰链的PC和PE类磷脂分子。推测适应进化菌株通过膜磷脂重塑提高细胞膜完整性,对酚类抑制物起到选择性屏障作用,从而保持细胞活性。     

Effect of volatiles emitted from wilted Populus nigra L. leaves on the mating and oviposition of Helicoverpa armigera (Hübner)

Wilted black poplar, Populus nigra ‘Italica’ L., leaves are very attractive to a vast number of noctuid moth species. This provides an opportunity for the development of effective trapping methods for the integrated management of pest species, such as Helicoverpa armigera, a major global and economically important insect pest.In the present study, we investigated the (1) nocturnal attraction patterns of H. armigera males and females to wilted P. nigra leaves; (2) effects of P. nigra volatiles on the mate-searching behavior of males through laboratory serial-chamber bioassays and field trapping; and (3) effects of P. nigra volatiles on the ovipositional choice and reproductive performance of females. Females and males, when tested alone, could be attracted by wilted P. nigra leaves, and the time periods of the first two attraction peaks were largely overlapped between sexes. Streams consisting of wilted P. nigra leaves and virgin females were not more attractive than virgin females alone, regardless of the stream sequence in a serial chamber. However, a stream of virgin females passed through wilted P. nigra leaves was more attractive than wilted P. nigra leaves alone. The addition of P. nigra extracts and its major aromatic components to the sex lure of H. armigera did not attract more moths than the sex lure alone. The volatiles from wilted P. nigra leaves were significantly more attractive to ovipositing females than those from cotton, tomato, and corn leaves, but equally attractive to tobacco leaves. Females exposed to volatiles from different leaves (P. nigra, cotton, and tobacco) showed similar fecundities. In summary, the attraction of moths to wilted P. nigra leaves may be attributable to multiple mechanisms, including the adsorption of sex pheromones, ovipostional attraction, and possible feeding attraction.     

环境温度和体型大小对花绒寄甲成虫死亡率及产卵量的影响

[目的]花绒寄甲Dastarcus helophoroides是天牛类林木蛀干害虫的主要天敌昆虫,为提升花绒寄甲的人工繁育技术和繁育质量,在不同环境温度下,测试了不同体型大小的花绒寄甲对成虫死亡率和产卵量的影响.[方法]按成虫体型大小将花绒寄甲分成较大、较小和中等3组,根据前期不同温度下的饲养经验,分别测试成虫在20、24和28℃下的存活率和产卵量.[结果]体型相同的个体随环境温度升高死亡率增加;20℃时体型小的死亡率高,24℃和28℃各组死亡率无显著性差异;中等个体组在24℃和28℃下的产卵量大于在20℃下的产卵量;同一温度条件下,体型显著影响雌虫的产卵量,体型大者产卵量高.[结论]体型大小对成虫死亡率影响不明显,但对产卵量有较大影响.     

Asymmetric biocatalysis of S-3-amino-3-phenylpropionic acid with new isolated Methylobacterium Y1-6

β-amino acids are widely used in drug research, and S-3-amino-3-phenylpropionic acid (S-APA) is an important pharmaceutical intermediate of S-dapoxetine, which has been approved for the treatment of premature ejaculation. Chiral catalysis is an excellent method for the preparation of enantiopure compounds. In this study, we used (±)-ethyl-3-amino-3-phenylpropanoate (EAP) as the sole carbon source. Three hundred thirty one microorganisms were isolated from 30 soil samples, and 17 strains could produce S-APA. After three rounds of cultivation and identification, the strain Y1-6 exhibiting the highest enantioselective activity of S-APA was identified as Methylobacterium oryzae. The optimal medium composition contained methanol (2.5 g/L), 1,2-propanediol (7.5 g/L), soluble starch (2.5 g/L), and peptone (10 g/L); it was shaken at 220 rpm for 4–5 days at 30 °C. The optimum condition for biotransformation of EAP involved cultivation at 37 °C for 48 h with 120 mg of wet cells and 0.64 mg of EAP in 1 ml of transfer solution. Under this condition, substrate ee was 92.1% and yield was 48.6%. We then attempted to use Methylobacterium Y1-6 to catalyze the hydrolytic reaction with substrates containing 3-amino-3-phenyl-propanoate ester, N-substituted-β-ethyl-3-amino-3-phenyl-propanoate, and γ-lactam. It was found that 5 compounds with ester bonds could be stereoselectively hydrolyzed to S-acid, and 2 compounds with γ-lactam bonds could be stereoselectively hydrolyzed to (-)-γ-lactam.     

Different utilizable substrates have different effects on cometabolic fate of imidacloprid in Stenotrophomonas maltophilia

Imidacloprid, the largest selling insecticide in the world, is more stable in soil, and its environmental residue and effects are attracting people's close attention. One of imidacloprid metabolism pathways was degraded to CO₂ through olefin imidacloprid pathway. Here, we report that sucrose as a utilizable substrate enhanced the cometabolism of imidacloprid by Stenotrophomonas maltophilia CGMCC 1.1788 to produce 5-hydroxy imidacloprid, whereas when succinate was used as a utilizable substrate, 5-hydroxy imidacloprid from imidacloprid was transformed to olefin imidacloprid, and the latter was further degraded. The hydroxylation of imidacloprid required NAD(P)H, whereas the dehydration of 5-hydroxy imidacloprid to form olefin imidacloprid required succinate rather than NAD(P)H. NADPH greatly favored the hydroxylation of imidacloprid more than NADH, and NADPH inhibited the dehydration of 5-hydroxy imidacloprid to olefin imidacloprid, but NADH did not. Therefore, sucrose may be metabolized through hexose monophosphate pathway to produce mainly NADPH which participated in the hydroxylation of imidacloprid to 5-hydroxy imidacloprid and meanwhile inhibited the dehydration of 5-hydroxy imidacloprid to olefin imidacloprid, whereas succinate may be metabolized mainly through the tricarboxylic acid cycle to produce NADH which was involved in hydroxylation of imidacloprid to 5-hydroxy imidacloprid but did not inhibit the dehydration of 5-hydroxy imidacloprid to olefin imidacloprid. Our results have a significant meaning in further understanding the influence of different utilizable substrates on the cometabolic pathways and the fate of environmental imidacloprid.     

植物细胞工程技术生产紫杉醇研究进展

紫杉醇是一种二萜类生物碱,主要从红豆杉树皮中分离提取。目前采用植物细胞工程技术是提高紫杉醇产率、保护稀缺资源红豆杉、解决紫杉醇药源紧缺的一种最有效方法。该文对近十年来国内外有关采用植物细胞工程技术生产紫杉醇的研究进展,包括红豆杉细胞系的建立、悬浮培养条件的研究、生物反应器培养以及紫杉醇合成代谢调控方面的最新研究进展进行综述。并重点论述了前体、诱导子和代谢支路抑制剂对红豆杉细胞悬浮培养生产紫杉醇的影响,为植物细胞工程技术生产紫杉醇提供借鉴和参考。     

黄河三角洲典型植被与地下水埋深和土壤盐分的关系

土壤盐分和地下水埋深是影响黄河三角洲植被发育和分布的重要因素.本文通过野外调查与统计分析,研究了黄河三角洲区域典型植被(翅碱蓬 柽柳、刺槐、芦苇和棉花)、地下水埋深、土壤盐分之间的关系.结果表明: 研究区地下水埋深显著影响土壤盐分,平均影响系数为0.327,地下水埋深在0.5～1.5 m的土壤盐渍化最严重;整个研究区内植被发育较差,其中,研究区78%面积的归一化植被指数(NDVI)<0.4,地下水埋深、土壤盐分对天然植被分布有显著影响;土壤盐分对研究区翅碱蓬-柽柳、刺槐、芦苇及棉花NDVI的影响显著,地下水埋深对翅碱蓬-柽柳NDVI的影响显著,对芦苇、棉花、刺槐NDVI的影响不显著.