Evaluation of methanotroph (Methylococcus capsulatus,Bath) bacteria meal as an alternative protein source for growth performance,digestive enzymes,and health status of Pacific white shrimp (Litopenaeus vannamei)

Aquaculture International - The increasing cost of fishmeal (FM) with limited supply and the continuous development of aquaculture necessitate more economical FM substitutes. This study aimed to...     

Soil aggregation may be a relevant indicator of nutrient cation availability

Key message

Aggregation was studied in two acidic forest soils (NE France) to investigate the potential link between available Ca and Mg content and soil aggregate size distribution and properties. Clay content influenced the aggregation status while clay mineralogy influenced aggregate stability and dynamics. Aggregation status and reactivity of soil components contributed to the difference of exchangeable Ca and Mg content in topsoil between the two sites.

Context

Though nutrient fluxes are important to define forest soil chemical fertility, the quantification of nutrient reservoirs in the soils and their availability to tree uptake is essential. A thorough understanding of nutrient availability requires an investigation of nutrient location and distribution in the soil solid phase.

Aims

The general aim was to investigate the potential link between available Ca and Mg content and soil aggregate size distribution and their properties (chemical, physical, mineralogical).

Methods

Soil aggregates were separated according to three size classes (200–2000 μm; 50–200 μm; <?50 μm) in two forest soils of the Lorraine plateau (France), both classified as Luvisols ruptic. The physical, chemical, and mineralogical properties were measured for each aggregate class.

Results

We showed that the relative abundance of an intermediate aggregate class [200–50 μm] was relevant to explain the difference of exchangeable Ca and Mg between sites. These aggregates were the poorest in organic and reactive mineral components and were unstable, which may mitigate the retention of Ca and Mg by ion-exchange.

Conclusion

This study highlights the role of aggregation and reactivity of soil components as relevant determinants of cation availability to tree uptake in soils.

     

Rheological Properties of Soft Wheat Flour Doughs: Effect of Salt and Triglycerides

The small deformation rheological properties of wheat flour doughs in relation to their structure and hydration were studied by dynamic mechanical thermal analysis, differential scanning calorimetry, and electron spin resonance. The effect of salt and triglycerides was also examined and compared with results we obtained previously on starch dispersions. Moisture content was adjusted to 48 or 60% (w/w, wb). Samples contained 0–16% NaCl (g/100 g of flour‐water) and 0–18% triolein or lard (g/100 g of flour‐water). The obtained results suggested that starch has an active role in determining the evolution of dough rheological characteristics during heating. The main factors controlling rheological behavior during thermal treatment are the volume fraction and deformability of starch granules. Gluten changes the viscoelasticity of the continuous phase and competes with starch for water. The addition of sodium chloride to flour dispersions shifted the structural disorganization and rigidity increased during heating to higher temperatures. At >7% NaCl, the reverse effect was observed. The mechanism controlling the effect of salt on dough rheological behavior was explained in terms of effect on water properties and on starch structure and hydration. Triglycerides had a lubricant effect (i.e., lowering G′ modulus) on the wheat flour dough system. These effects are of great importance for production and quality of bakery products.     

Antioxidants, phenolic compounds, and nutritional quality of different strawberry genotypes

Strawberry contains high levels of micronutrients and phytochemical compounds. These exhibit functional roles in plant growth and metabolism and are also essential for the nutritional and organoleptic qualities of the fruit. The aim of the present work was to better characterize the phytochemical and antioxidant profiles of the fruit of nine different genotypes of strawberry, by measuring the total flavonoid, anthocyanin, vitamin C, and folate contents. Cultivar effects on the total antioxidant capacities of strawberries were also tested. In addition, the individual contribution of the main antioxidant compounds was assessed by HPLC separation coupled to an online postcolumn antioxidant detection system. This study showed the important role played by the genetic background on the chemical and antioxidant profiles of strawberry fruits. Significant differences were found between genotypes for the total antioxidant capacity and for all tested classes of compounds. The HPLC analyses confirmed qualitative and quantitative variability in the antioxidant profiles. These studies show that differences exist among cultivars, applicable in dietary studies in human subjects.     

二维电泳技术在大豆子叶微粒体膜结合蛋白研究中的应用

以硝酸银诱导的大豆子叶为材料,初步探讨了二维电泳技术在分离大豆子叶微粒体膜结合蛋白中的应用,研究了重新水化溶液的组成、加样量、等电聚焦的total voltage hours以及不同pH梯度范围IPG(固相pH梯度)胶条等因素对膜蛋白的溶解和二维电泳图像的影响.结果表明对于70×3×0.5mm IPG胶条,能够溶解较多蛋白质和获得高质量二维电泳图像的优化条件为:由尿素、硫脲、三丁基膦和C7BZO组成的重新水化溶液(TUC7T2)、80μg的加样量和20000vhr的total voltage hour.在此优化条件下,与宽范围pH梯度IPG胶条相比,使用窄范围pH梯度胶条可以观察到更多的和质量更好的蛋白质点,结果发现至少有13个点只存在于硝酸银诱导的样品中,而不存在于对照中,其代表的蛋白质的等电点在4.0～8.0.     

Genome of the host-cell transforming parasite Theileria annulata compared with T. parva

Theileria annulata and T. parva are closely related protozoan parasites that cause lymphoproliferative diseases of cattle. We sequenced the genome of T. annulata and compared it with that of T. parva to understand the mechanisms underlying transformation and tropism. Despite high conservation of gene sequences and synteny, the analysis reveals unequally expanded gene families and species-specific genes. We also identify divergent families of putative secreted polypeptides that may reduce immune recognition, candidate regulators of host-cell transformation, and a Theileria-specific protein domain [frequently associated in Theileria (FAINT)] present in a large number of secreted proteins.     

Monitoring the fate of a 30-year-old truffle orchard in Burgundy: from Tuber melanosporum to Tuber aestivum

Truffles, i.e. tree root-associated fungal fruiting bodies, clearly range among the world’s most exclusive delicacies. Despite the quite restricted natural geographic occurrence of one of the most renowned fungal species, namely Tuber melanosporum, the development of inoculation procedures in the late 1960s made it possible to enlarge its production area in different countries. This was achieved by planting orchards with host tree seedlings colonized by the fungus. In the present work, we investigate the behavior of one of the earliest T. melanosporum orchards planted in Burgundy (France) over a long-term scale (more than 30 years). A picture of the orchard evolution was obtained by recording truffle yields and fungal morphotypes over the seasons and relating them to host-tree development and climate data. The most relevant results include the time-delayed, but rather fast replacement of inoculated T. melanosporum by naturally occurring T. aestivum and the key role of climate in the inter-annual variability of truffle production.     

IMAGING DIAGNOSIS—PARAGANGLIOMA OF THE CAUDA EQUINA: MR FINDINGS

The magnetic resonance imaging features of a cauda equina paraganglioma in a 5‐year‐old dog are described. Imaging revealed a well‐defined, strongly contrast‐enhancing mass invading the adjacent vertebral body and infiltrating the intervertebral foramen bilaterally. Flow void, compatible with increased drainage veins around the mass, and macroscopically visible neovessels in contrast‐enhanced magnetic resonance angiography, as reported in numerous human studies, were not visible in this single case. The tumor recurred despite aggressive surgery and radiotherapy. This neoplasm should be considered in the differential diagnosis of cauda equina abnormalities in dogs.