Sequestration of distasteful compounds by some pharmacophagous insects

Several pharmacophagous insects have been shown to sequester specific kairomonal substances or their derivatives in their body tissues. Turnip sawflies,Athalia rosae, visit a plant,Clerodendron trichototmum (Verbenaceae), and feed voraciously on the leaf surface. Clerodendrins were characterized as the potent phagostimulants forA. rosae adults. The insect sequesters some of the analogs and becomes extremely bitter on its body surface. Some chrysomelid leaf beetles associated with cucurbitacins were found to store high concentrations of these bitter principles in their body. South American polyphagous beetles,Diabrotica speciosa andCerotoma arcuata, are strongly arrested by root components from the cucurbit plant,Ceratosanthes hilariana, and selectively accumulate 23,24-dihydrocucurbitacin D, effectively gaining bitterness. Similarly, four species of Asian pumpkin leaf beetles belonging to the genusAulacophora were shown to sequester the same compound in body tissue as the major bitter principle. Three phenylpropanoids closely related to methyl eugenol were found to accumulate in the rectal glands of the male Oriental fruit fly,Dacus dorsalis. One of the rectal gland components, 2-allyl-4,5-dimethoxyphenol was shown to be released in the air during courtship. In all of these cases, selectively sequestered compounds strongly deterred feeding by some predators, thus serving as allomones in this context. Kairomonal and pheromonal functions linked with allomonal sequestration by pharmacophagous feeding has also been suggested.     

Plant growth regulatory activities of artemisinin and its related compounds

Artemisinin, a sesquiterpene lactone produced in the leaves ofArtemisia annua, was evaluated for its phytotoxicity in mono- and dicotyledonous plants. Artemisinin inhibited seed germination, seedling growth, and root induction in all species tested. The concentration of artemisinin required for 50% inhibition ofLemna minor growth was 5 M. Inhibitory plant responses appeared to require the endoperoxide moiety of this compound since similar chemicals without endoperoxide, deoxyartemisinin, arteannuic acid, and arteannuin B, were less phytotoxic. InL. minor, artemisinin and arteannuic acid caused the leakage of proteins into the growth medium, suggesting the site of activity was at the plant cell membrane.     

Modelling the survival of starter lactic acid bacteria and Bifidobacterium bifidum in single and simultaneous cultures

The inactivation kinetics at 4 degrees C of Bifidobacterium bifidum, Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, cultured alone or consociated in a laboratory medium (modified MRS broth), were modelled through the Weibull model and a second-order polynomial equation. The initial cell number of S. thermophilus and L. delbrueckii subsp. bulgaricus was approximately 6-7log (CFU/ml); the viability loss after 30 days of storage was 2.87 and 1.99log (CFU/l) for L. delbruckii subsp. bulgaricus and S. thermophilus, cultured alone, respectively; whereas the consociation of lactobacilli and streptococci with bifidobacteria reduced viability loss during storage (0.28 and 0.54log CFU/l for lactobacilli and streptococci, respectively). Finally, the consociation of lactobacilli and streptococci with B. bifidum improved their oxygen uptake.     

环境因素对长双歧杆菌CICC6069生物膜生成的影响

目的:研究不同环境因子对长双歧杆菌CICC6069生物膜生成能力的影响。方法:通过增添或删除培养基MRS和TSB的组成成分,改变双歧杆菌培养的营养和环境条件,测定不同条件对双歧杆菌生物膜生成的影响。结果:不同环境因子对双歧杆菌生物膜生成的影响不同,葡萄糖、MgSO4及渗透压可促进长双歧杆菌CICC6069生物膜的生成;EDTA、大豆蛋白胨及pH可抑制长双歧杆菌生物膜的生成;MnSO4对双歧杆菌生物膜生成的影响有培养基依赖性。结论:长双歧杆菌CICC6069生物膜的生成依赖环境条件,不同环境因子对长双歧杆菌生物膜的生成有不同的影响。其中,MgSO4、NaCl、葡萄糖对双歧杆菌生物膜生成的影响比较显著。     

Identification of bifidobacteria from dairy products and evaluation of a microplate hybridization method

Sixteen strains of Bifidobacterium isolated from 15 dairy products such as yogurt, cultured milk, butter and cheese were characterized on the basis of phenotypic characteristics and DNA similarities were examined by a microplate hybridization method. Three of the strains were identified as Bifidodobacterium longum, one strain was identified as Bifidobacterium bifidm, and one strain was assigned to the species Bifidobacterium breve on the basis of phenotypic characteristics, and this identification was confirmed by the analysis of DNA similarities. The remaining 11 strains could not be identified by examining their phenotypic characteristics and, contrary to the product label information, these strains were identified as Bifudidobacterium animalis on the basis of DNA similarities. The applicability of the colorimetric hybridization method in micro dilution wells to genetic identification of Bifidobacterium species was also studied.     

Characteristic Anthocyanin Pattern from Onions and other Allium spp

Three red onion (Allium cepa) cultivars, top onion (A. cepa var. vivi-parum), A. altaicum and chive (A. schoenoprasum) contained several or all of the following anthocyanins: 3-(6′-malonyl-3′-glucosylglucoside), 3-(3′,6′-dimalonylglucoside), 3-(6′-malonylglucoside), 3-(3′-malonyl-glucoside), 3-(3′-glucosylglucoside) and 3-glucoside of cyanidin. Trace amounts of two pelargonidin derivatives and the 3,5-diglucosides of cyanidin and peonidin were for the first time reported in red onion. Carbon NMR data showed that the sugars of the 3-(6′-malonyl-3′-glu-cosylglucoside), 3-(6′-malonylglucoside) and 3-glucoside of cyanidin were pyranoses. Substitution either by sugar or acid in the sugar 3-position of an anthocyanin has never been reported outside the genus Allium.     

Effects of suni-bug (<Emphasis Type="Italic">Eurygaster</Emphasis> spp.) damage on size distribution of durum wheat (<Emphasis Type="Italic">Triticum durum</Emphasis> L.) proteins

Wholemeal samples were obtained from five durum wheat cultivars at two different bug (Eurygaster spp.) damage levels (medium and high damage). The samples were incubated (60 and 120 min) and used in size exclusion high performance liquid chromatography (SE-HPLC) analyses. The results showed that the amount of larger polymeric protein (TP1) and smaller polymeric protein (TP2) obtained from total (sodium dodecyl sulfate soluble) proteins decreased significantly in the bug-damaged samples, while the amount of total larger monomeric proteins (TP3) increased. The polymeric/monomeric protein ratio of all cultivars decreased at 60 min of incubation with increasing damage level. For all cultivars, the ratio of unextractable polymeric protein (UPP%) significantly decreased at 60 min of incubation except cv. Diyarbakir. The results suggested that bug protease caused depolymerization and/or disaggregation of polymeric proteins to lower their average molecular size. The changes in protein structure as determined using SE-HPLC supported by the decreases in gluten content and gluten index values which decreased with suni-bug damage. Deteriorative effects of bug damage on durum wheat quality were found to be quite similar to those on bread wheats.     

新疆野蔷薇种子油的脂肪酸组成分析

采用超声辅助提取法提取野蔷薇种子油,以气相色谱-质谱联用技术对油脂进行脂肪酸组成分析.结果表明:野蔷薇种子油中的主要脂肪酸为棕榈酸、油酸、亚油酸、亚麻酸,其中不饱和脂肪酸占总量的92.41%;主要成分棕榈酸占5.88%,油酸占12.39%,亚油酸占56.52%,亚麻酸占23.50% .     

微囊化双岐杆菌的研究

本介绍了双歧杆菌的特性及其保健功能，对培养出的双歧杆菌进行微囊化技术处理并研究其稳定性，同时介绍了微囊化双岐杆菌在食品工业上的应用。