St. John’s Wort Herbal Teas – Biological Potential and Chemometric Approach to Quality Control

Plant Foods for Human Nutrition - St. John’s wort has been used for centuries in traditional medicine of many cultures, and nowadays it is well-known as a clinically important antidepressant...     

Sorghum Pasta and Noodles: Technological and Nutritional Aspects

Plant Foods for Human Nutrition - Sorghum is a major cereal crop with various agronomic advantages, contains health-promoting compounds and is gluten-free. There is a growing tendency to use...     

Enzyme Bioprospection of Marine-Derived Actinobacteria from the Chilean Coast and New Insight in the Mechanism of Keratin Degradation in Streptomyces sp. G11C

Marine actinobacteria are viewed as a promising source of enzymes with potential technological applications. They contribute to the turnover of complex biopolymers, such as pectin, lignocellulose, chitin, and keratin, being able to secrete a wide variety of extracellular enzymes. Among these, keratinases are a valuable alternative for recycling keratin-rich waste, which is generated in large quantities by the poultry industry. In this work, we explored the biocatalytic potential of 75 marine-derived actinobacterial strains, focusing mainly on the search for keratinases. A major part of the strains secreted industrially important enzymes, such as proteases, lipases, cellulases, amylases, and keratinases. Among these, we identified two streptomycete strains that presented great potential for recycling keratin wastes—Streptomyces sp. CHA1 and Streptomyces sp. G11C. Substrate concentration, incubation temperature, and, to a lesser extent, inoculum size were found to be important parameters that influenced the production of keratinolytic enzymes in both strains. In addition, proteomic analysis of culture broths from Streptomyces sp. G11C on turkey feathers showed a high abundance and diversity of peptidases, belonging mainly to the serine and metallo-superfamilies. Two proteases from families S08 and M06 were highly expressed. These results contributed to elucidate the mechanism of keratin degradation mediated by streptomycetes.     

Application to soil of disinfectants through irrigation reduces Verticillium dahliae in the soil and verticillium wilt of olive

The application of disinfectants through drip irrigation could be a feasible practice against verticillium wilt (Verticillium dahliae) of olive. OX-VIRIN (activated peroxide) and OX-AGUA AL25 (quaternary ammonium compounds) are two disinfectants that have shown efficacy against V. dahliae in irrigation water and potential for reducing the disease in young olive plants. In this work, various post-planting application strategies incorporating OX-VIRIN (once a month, or twice a month on alternate or successive weeks) or OX-AGUA AL25 (once a month, or twice a month on alternate weeks) were assessed for their effect on V. dahliae in soil, disease in olive trees, and olive yield, in a 2-year pot-experiment under natural environmental conditions. The disinfectants were injected via metering pumps into a drip irrigation system that irrigated olive trees planted in V. dahliae-inoculated soil. All the application strategies significantly reduced the total inoculum density in soil compared to controls with no disinfectants and noninoculated soil. The microsclerotia density was also significantly reduced in disinfested soils by 73.6–86.8%, depending on the strategy. The symptoms and infection incidence were always lower in treatments subjected to disinfestation. The treatment with OX-AGUA AL25 applied twice a month on alternate weeks most reduced the symptoms (by 53.0%) and colonization index (by 70.8%) with respect to untreated water control. This soil disinfestation also significantly strengthened the symptom remission. Tree growth and production were negatively affected by soil inoculation (reduced by 45.6% and 88.7%, respectively), but not so by disinfectants, which even relieved the reduction in inoculated soils, especially when OX-AGUA AL25 was applied.     

Strategy to identify resistance to white mould associated with high yield for irrigated common bean in Brazil

Development of common bean cultivars with partial white mould resistance through breeding techniques has been a challenge in Brazil. As yet, lines/cultivars from breeding programmes have not been investigated for resistance; therefore, this study screened 107 lines/cultivars for their reactions to white mould in 14 preliminary trials conducted under irrigation. Thirteen resistant lines/cultivars (three of Andean origin) and six Mesoamerican cultivars (three intermediately resistant and three susceptible) were selected for further investigation. These lines/cultivars and the resistant control A195 were evaluated in six advanced trials and two straw tests to assess the effectiveness of the screening procedure. In 11 preliminary trials, screenings were performed under moderate/high or higher disease pressure. These pressures occurred in two advanced trials in which, when yields were averaged across moderate/high and high pressures, 10 Mesoamerican lines/cultivars selected for resistance yielded 14%, 23%, and 38% more than intermediately resistant cultivars, A195, and susceptible cultivars, with median disease ratings (1–9 scale) of 4.5, 5.7, 5.7, and 6.7, respectively. In the straw test, three Andean lines/cultivars (A195 included) and two susceptible cultivars in the field were among those with the highest levels of physiological resistance. Thus, field rating under high disease pressure and greenhouse rating did not correlate significantly, suggesting that field trials are critical to evaluating resistance and to identifying high-yielding beans. Therefore, lines/cultivars from breeding programmes assessed in field trials may provide a low cost and fast way to identify high-yielding bean cultivars with partial resistance to white mould in the subtropical southern hemisphere.     

Prediction of Genetic Gain in Sweet Corn using Selection Indexes

Journal of Crop Science and Biotechnology - The cultivation of sweet corn is expanding in Brazil, but there are serious constraints about the availability of commercial cultivars. The selection of...     

The Ischigualasto Tetrapod Assemblage (Late Triassic, Argentina) and 40Ar/39Ar Dating of Dinosaur Origins

(40)Ar/(39)Ar dating of sanidine from a bentonite interbedded in the Ischigualasto Formation of northwestern Argentina yielded a plateau age of 227.8 +/- 0.3 million years ago. This middle Carnian age is a direct calibration of the Ischigualasto tetrapod assemblage, which includes some of the best known early dinosaurs. This age shifts last appearances of Ischigualasto taxa back into the middle Carnian, diminishing the magnitude of the proposed late Carnian tetrapod extinction event. By 228 million years ago, the major dinosaurian lineages were established, and theropods were already important constituents of the carnivorous tetrapod guild in the Ischigualasto-Villa Unión Basin. Dinosaurs as a whole remained minor components of tetrapod faunas for at least another 10 million years.     

国槐枝叶水分特征及其对树干边材液流的影响

为探明国槐Sophora japonica组织含水量、水势、水容等枝叶水分特征及其对树干边材液流的调节和影响,于2007年3月下旬至2008年3月下旬利用热扩散式边材液流检测技术(TDP)、压力室技术等对生长在北京林业大学校园内的国槐树干边材液流、组织含水量、水势、水容等进行了系统研究。结果表明:城市环境下,(1)国槐树干边材液流速率日变化春季和夏季呈双峰曲线,秋季呈单峰曲线;液流峰值出现时间春季最早,夏季次之,秋季最晚;春季和秋季液流速率峰值较夏季高,但峰值维持时间夏季较春、秋两季长。(2)国槐枝条与叶片绝对含水量、水势、水容具有相似的日变化规律,但不同季节日变化有所差异。(3)整个生长季,国槐含水量、水势、水容的大小排序为春季夏季秋季;枝条平均含水量(52.12±2.59)%叶片平均含水量(69.59±4.64)%;枝条平均水势(-1.70±0.74)MPa叶片平均水势(-1.87±0.65)MPa;枝条水容(1.488±3.060)g.cm-3.MPa-1叶片水容(5.86±6.70)×10-3g.cm-3.MPa-1。(4)国槐组织水容日变化与树干边材液流速率日变化反向相关,国槐枝叶含水量、水势、水容等共同作用和调节其蒸腾耗水。     

刺五加鲨烯合酶基因的表达及其对皂苷含量的影响

为了了解刺五加鲨烯合酶基因(squalene synthase,SS)的表达特点及其对刺五加中皂苷含量的影响情况,以GAPDH基因为内参照基因,采用实时定量PCR技术,分析了SS基因在刺五加不同生长发育时期不同器官中的表达量及茉莉酸甲酯对其表达的影响情况;还利用SPSS 17.0软件分析了SS基因的表达量与刺五加中皂苷总含量的相关性。结果表明,在刺五加的整个生长期中,SS基因的表达量呈现出"低—高—低—高—低"的变化趋势:萌芽期(4月26日)该基因的表达量最低,而盛花期(6月26日)该基因的表达量最高,为萌芽期的3.11倍;SS基因在刺五加根中的表达量显著高于茎、叶和叶柄中的表达量(P<0.05),其在茎中的表达量最低,仅为根中表达量的51.88%。茉莉酸甲酯可提高SS基因的表达量,但其与对照组的差异未达到显著水平。刺五加中的皂苷总含量与SS基因的表达量间呈现出同升同降的变化趋势,存在极显著的正相关关系(P<0.01)。文中初步判定,鲨烯合酶是刺五加皂苷生物合成的关键酶。