Conditions for the production of Agrocin 84 byAgrobacterium radiobacter K84

Summary A chemically defined medium was developed that supported the growth ofAgrobacterium radiobacter K84 and the production of agrocin 84. Various supplements were investigated for their effect on growth rate and production of agrocin 84 using a well-diffusion assay method. Mannitol was found to be a better substrate for growth ofA. radiobacter K84 compared to the other sugar alcohols and sugars tested. By contrast,d-fructose was the better substrate for the production of agrocin 84. Biotin supplementation stimulated production of agrocin 84 but did not eliminate the diauxic lag seen with the basal medium. The opine, octopine, inhibited growth ofA. radiobacter K84 and production of agrocin 84 as did coenzyme B₁₂. By contrast, the cytokinin, isopentenyl adenosine, was marginally stimulatory to production, as was vitamin B₁₂. Acetosyringone supplementation had a negligible effect on growth rate and production of agrocin 84.     

Oxygen and mannitol consumption ofRhizobium meliloti in relation to symbiotic nitrogen fixation efficiency

Summary The rate of oxygen and total mannitol consumption were studied with 48 strains ofRhizobium meliloti in relation to their symbiotic nitrogen fixation efficiency as expressed by the plants dry weight yields. The rate of oxygen consumption is positively correlated to the total mannitol consumption and significant inverse relationship between these two physiological properties and symbiotic efficiency are apparent. The possibility of using the rate of oxygen consumption as a preselection tool is discussed.Contribution no159.     

Abiotic stress tolerance in transgenic eggplant (Solanum melongena L.) by introduction of bacterial mannitol phosphodehydrogenase gene

In the present work, the bacterial mannitol-1-phosphodehydrogenase(mtlD) gene was introduced into eggplant(Solanummelongena L.) by Agrobacteriumtumefaciens-mediated transformation. Several transformants weregenerated and the transgene integration was confirmed by PCR, dot blot andSouthern blot analysis. Transgenic lines of T₀ and T₁generations were examined for tolerance to NaCl-induced salt stress,polyethylene glycol-mediated drought and chilling stress under bothinvitro and in vivo growth conditions. Aconsiderable proportions of transgenic seeds germinated and seedlings grew wellon 200 mM salt-amended MS basal medium, whereas seeds ofuntransformed control plants failed to germinate. Further, leaf explants fromthe transgenics could grow and showed signs of shoot regeneration onsalt-amended MS regeneration medium, whereas wild type did not respond, and infact the explants showed necrosis and loss of chlorophyll after about one week.The transgenic leaves could also withstand desiccation, and transgenics couldgrow well under chilling stress, and hydroponic conditions with salt stress ascompared to wild type plants. Thus, the transgenic lines were found to betolerant against osmotic stress induced by salt, drought and chilling stress.The morphology of the transgenic plants was normal as controls, but thechlorophyll content was higher in some of the lines. These observations suggestthat mtlD gene can impart abiotic stress tolerance ineggplant.     

吡拉西坦联合甘露醇对老年脑出血后脑水肿的疗效比较

目的:观察吡拉西坦联合甘露醇对老年脑出血后脑水肿患者颅内压、脑水肿体积、脑血肿体积及认知功能的影响。方法:104例脑出血后脑水肿老年患者随机分为观察组(54例)和对照组(50例)。对照组在常规治疗的基础上给予20%甘露醇注射液,观察组在对照组的基础上给予吡拉西坦注射液。治疗7天,观察两组颅内压、脑水肿体积、脑血肿体积及认知功能(分别采用MMSE、Mo CA评估)的变化。结果:治疗后,两组颅内压、脑水肿体积、脑血肿体积均明显下降而MMSE、Mo CA明显上升,且观察组各指标变化幅度均大于对照组,治疗后同期比较差异均有统计学意义(P0.05)。结论:吡拉西坦联合甘露醇治疗老年脑出血后脑水肿,控制颅内压、改善脑水肿与脑血肿,作用优于单用甘露醇,能更大程度保护认知功能。     

The effects of mannitol and salinity stresses on growth and biochemical accumulations in lemon balm

The effects of saline irrigation water and mannitol on the growth and content of essential oil, photosynthetic pigments, soluble sugars, proline, Na, macroelements (N–P–K) and microelements (Mg–Zn–Fe–Mn) of lemon balm (Melissa officinalis L.) plants were investigated. Saline irrigation water decreased certain growth characters (total leaf area, leaf number, and total fresh and dry mass). The photosynthetic pigments (chlorophylls a and b, total carotenoids) and mineral content (N–P–K–Mg–Zn–Fe–Mn) also decreased as saline irrigation water level increased. Saline irrigation water promoted the accumulation of essential oil content and its main components (citronellal, citronellol and geranyl acetate) as well as total soluble sugars, proline and Na⁺ contents. The plants treated with saline irrigation water × mannitol resulted in higher plant growth, essential oil, total soluble sugars, proline, macro and micronutrient values than those treated with saline irrigation water alone, photosynthetic pigments and Na demonstrated an opposite trend.     

A new phenylethanoid triglycoside in Veronica beccabunga L

Besides the expected iridoid glucosides aucubin and catalpol as well as three known esters of the latter, Veronica beccabunga (brooklime) was shown to contain five carboxylated iridoid glucosides, namely gardoside, mussaenosidic acid, 8-epiloganic acid, arborescosidic acid and alpinoside. In addition to these compounds, the plant contained salidroside and a previously unknown caffeoyl phenylethanoid glycoside (CPG) which we have named chionoside J. The structure was elucidated mainly by 1D and 2D NMR spectroscopy to be 2″-(β-glucopyranosyl)-plantamajoside. The distribution of plantamajoside and its derivatives as well as that of carbocyclic iridoids with an 8,9-double bond is briefly discussed, and it is noted that such compounds are mainly confined to the tribe Veroniceae of the Plantaginaceae.     

Biotechnological conversions of bio‐diesel‐derived crude glycerol by Yarrowia lipolytica strains

In the present report, crude glycerol, waste discharged from bio‐diesel production, was used as carbon substrate for three natural Yarrowia lipolytica strains (LFMB 19, LFMB 20 and ACA‐YC 5033) during growth in nitrogen‐limited submerged shake‐flask experiments. In media with initial glycerol concentration of 30 g/L, all strains presented satisfactory microbial growth and complete glycerol uptake. Although culture conditions favored the secretion of citric acid (and potentially the accumulation of storage lipid), for the strains LFMB 19 and LFMB 20, polyol mannitol was the principal metabolic product synthesized (maximum quantity 6.0 g/L, yield 0.20–0.26 g per g of glycerol consumed). The above strains produced small quantities of lipids and citric acid. In contrast, Y. lipolytica ACA‐YC 5033 produced simultaneously higher quantities of lipid and citric acid and was further grown on crude glycerol in nitrogen‐limited experiments, with constant nitrogen and increasing glycerol concentrations (70–120 g/L). Citric acid and lipid concentrations increased with increment of glycerol; maximum total citric acid 50.1 g/L was produced (yield 0.44 g per g of glycerol) while simultaneously 2.0 g/L of fat were accumulated inside the cells (0.31 g of lipid per g of dry weight). Cellular lipids were mainly composed of neutral fraction, the concentration of which substantially increased with time. Moreover, in any case, the phospholipid fraction was more unsaturated compared with total and neutral lipids, while at the early growth step, microbial lipid was more rich in saturated fatty acids (e.g. C16:0 and C18:0) compared with the stationary phase.     

Chemotaxonomy of Veroniceae and its allies in the Plantaginaceae

In a chemosystematic investigation of tribe Veroniceae (Plantaginaceae), representatives of Camptoloma, Sibthorpia, Veronica subg. Pentasepalae and subg. Hebe, Veronicastrum, Wulfenia, and the related Ellisiophyllum and Globularia were examined for non-flavonoid glycosides. From the 14 species studied, 28 different iridoid glucosides and 10 caffeoyl phenylethanoid glucosides (CPGs), as well as salidroside and arbutin were isolated and characterized by NMR; of these, five compounds were previously unknown. It was found that the representatives of Veroniceae, as well as Globularia, were characterized by mannitol, aucubin, catalpol and catalpol esters. Each of the three studied species of Veronica subg. Hebe contained at least one of the 6-O-catalpol esters typical for Veronica s. str. (verminoside), supporting the inclusion of Hebe in Veronica. However, their main constituents were esters of 6-O-rhamnopyranosylcatalpol; a CPG, hebeoside (2'-beta-xylopyranosyl-verbascoside) was isolated from V. (Hebe) salicifolia. The two species of Veronicastrum also contained 6-O-rhamnopyranosylcatalpol esters, including the previously unknown 2',3'- and 3',4'-dicinnamoyl derivatives and, in contrast to the earlier reports, they lacked 6-O-catalpol esters. The main iridoid constituents in the three investigated species of Wulfenia were 10-O-aucubin and 10-O-catalpol esters (isoscrophularioside or globularin) while baldaccioside (10-O-cinnamoyl asystasioside E) was isolated from W. baldaccii. Globularia vulgaris contained 10-O-catalpol esters (e.g., globularin) and, in addition, asperuloside together with its benzoyl analogue named besperuloside. The representatives of Sibthorpia and Ellisiophyllum were almost completely devoid of iridoids; this, however, together with the CPGs present implied a close relationship between the two genera. Camptoloma lyperiiflorum lacked hexitols but contained esters of 6-O-rhamnopyranosylcatalpol different from those found in Veroniceae but known from Buddleja, Scrophularia and Verbascum (Scrophulariaceae s. str.).