Eugenia dittocrepis O.Berg

https://thekeep.eiu.edu/herbarium_specimens_byname/14679/thumbnail.jp

Increasing the Nutritional Value of Canola Meal via Fungal Bioprocessing

The main limitation of meals from canola and other Brassica spp. is the presence of glucosinolates (GLS), which are anti-nutritional and can even be toxic at high ingestion levels. Furthermore, large amounts of GLS can reduce palatability for livestock and thus reduce intake and growth rates. For this reason canola was bred to contain lower levels of GLS (\u3c30 μmol/g) and erucic acid (\u3c 2%). However, feed inclusion rates are still limited to ~30%, and this reduces the value of canola meal. The goal of this thesis was to optimize a pretreatment and fungal conversion process to enhance the nutritional value of canola meal. Various combinations of physical/chemical pretreatments, fungal cultures, and incubation methods were investigated to metabolize GLS into cell mass, CO2, or other non-toxic components. These treatments also served to hydrolyze canola meal fiber into carbohydrates which were then metabolized by the fungi into single cell protein. Solid-state incubation conditions were initially tested, since filamentous fungi are well adapted to grow at lower moisture levels, and this would potentially reduce contamination issues with bacteria. Flask trials were performed using 50% moisture, hexane extracted (HE) or cold pressed (CP) canola meal, with incubation for 168 h at 30ºC. On HE canola meal Trichoderma reesei (NRRL-3653) achieved the greatest increase in protein content (23%), while having the lowest residual levels of sugar (8% w/w) and GLS (0.4 μM/g). On CP canola meal T. reesei (NRRL-3653), Aureobasidium pullulans (NRRL-58522), and A. pullulans (NRRL-Y-2311-1) resulted in the greatest improvement in protein content (22.9, 16.9 and 15.4%, respectively), while reducing total GLS content from 60.6 μM/g to 1.0, 3.2 and 10.7 μM/g, respectively. GLS levels were reduced to 65.5 and 50.7% by thermal treatments while solid-state microbial conversion further reduced GLS up to 99 and 98% in HE and CP canola, respectively. Fiber levels increased due to the concentration effect of removing oligosaccharides and GLS. Submerged incubation conditions were also tested, as this approach is more commonly used in industry due to easier material handling and process control. Flask trials were performed using 10% moisture content HE or CP canola meal, with incubation for 168 h at 30ºC while being agitated at 150 rpm. Canola meals were either subjected directly to submerged incubation with the fungal strains, or were first saccharified with a cellulase enzyme cocktail and then incubated with the fungi. Aureobasidium pullulans (Y-2311-1), Fusarium venenatum and Trichoderma reesei resulted in the greatest improvements in protein levels in HE canola meal, at 21.0, 23.8, and 34.8%, respectively. These fungi reduced total GLS content to 2.7, 7.4, and 4.9 μM/g, respectively, while residual sugar levels ranged from 0.8-1.6% w/w. In trials with CP canola meal, the same three fungi increased protein levels by 24.6, 35.2, and 37.3%, and final GLS levels to 6.5, 4.0, and 4.7 μM/g, respectively, while residual sugar levels ranged from 0.3-1.0 % w/w. P. kudriavzevii was the only fungi able to significantly reduce ADF in both saccharified HE and CP canola meal, representing a reduction of 6.5 and 9.6%, respectively. Similar to solid-state incubation, most cases resulted in an increase of fiber levels due to the concentration effect of removing oligosaccharides and GLS

The preparation of high purity dysprosium, holmium and erbium by the lithium reduction of their trichloride salts

http://www.worldcat.org/oclc/3777293

Constraints on grain formation around carbon stars from laboratory studies of presolar graphite

We report the results of an investigation into the physical conditions in the mass outflows of asymptotic giant branch (AGB) carbon stars that are required for the formation of micron-sized presolar graphite grains, with and without previously formed internal crystals of titanium carbide (TiC). A lower mass limit of 1.1 M⊙ for stars capable of contributing grains to the solar nebula is derived. This mass limit, in conjunction with a mass-luminosity relation for carbon stars, identifies the region of the H-R diagram relevant to the production of presolar graphite. Detailed dynamical models of AGB outflows, along with constraints provided by kinetics and equilibrium thermodynamics, indicate that grain formation occurs at radii from 2.3 to 3.7 AU for AGB carbon stars in the 1.1-5 M⊙ range. This analysis also yields time intervals available for graphite growth that are on the order of a few years. By considering the luminosity variations of carbon stars, we show that grains formed during minima in the luminosity are likely to be evaporated subsequently, while those formed at luminosity maxima will survive. We calculate strict upper limits on grain sizes for graphite and TiC in spherically symmetric AGB outflows. Graphite grains can reach diameters in the observed micron size range (1-2 µm) only under ideal growth conditions (perfect sticking efficiency, no evaporation, no depletion of gas species contributing to grain growth), and then only in outflows from carbon stars with masses ≲ 2.5 M⊙. The same is true for TiC grains that are found within presolar graphite, which have mean diameters of 24 ± 14 nm. In general, the mass-loss rates that would be required to produce the observed grain sizes in spherically symmetric outflows are at least an order of magnitude larger than the maximum observed AGB carbon star mass-loss rates. These results, as well as pressure constraints derived from equilibrium thermodynamics, force us to conclude that presolar graphite and TiC must form in regions of enhanced density (clumps, jets) in AGB outflows having small angular scales. As shown in the companion paper by Croat et al., the enrichment of 12C in many AGB graphites, and the overabundances of the s-process elements Mo, Zr, and Ru in the carbides found within them, often greatly exceed the values observed astronomically in AGB outflows. These observations not only lend further support to the idea that the outflows are clumpy, but also imply that the outflowing matter is not well mixed in the circumstellar envelope out to the radii where grain condensation takes place

Lianas Have A Seasonal Growth Advantage Over Co‐Occurring Trees

The seasonal growth advantage hypothesis posits that plant species that grow well during seasonal drought will increase in abundance in forests with increasing seasonality of rainfall both in absolute numbers and also relative to co‐occurring plant species that grow poorly during seasonal drought. That is, seasonal drought will give some plant species a growth advantage that they lack in aseasonal forests, thus allowing them attain higher abundance. For tropical forest plants, the seasonal growth advantage hypothesis may explain the distribution of drought‐adapted species across large‐scale gradients of rainfall and seasonality. We tested the seasonal growth advantage hypothesis with lianas and trees in a seasonal tropical forest in central Panama. We measured the dry‐season and wet‐season diameter growth of 1,117 canopy trees and 648 canopy lianas from 2011 to 2016. We also evaluated how lianas and trees responded to the 2015–2016 El Niño, which was the third strongest el Niño drought on record in Panama. We found that liana growth rate was considerably higher during the dry‐season months than the wet‐season months in each of the five years. Lianas achieved one‐half of their annual growth during the 4‐month dry season. By contrast, trees grew far more during the wet season; they realized only one‐quarter of their annual growth during the dry season. During the strong 2015–2016 El Niño dry season, trees essentially stopped growing, whereas lianas grew unimpeded and as well as during any of the previous four dry seasons. Our findings support the hypothesis that seasonal growth gives lianas a decided growth advantage over trees in seasonal forests compared to aseasonal forests, and may explain why lianas peak in both absolute and relative abundance in highly seasonal tropical forests. Furthermore, the ability of lianas to grow during a strong el Niño drought suggests that lianas will benefit from the predicted increasing drought severity, whereas trees will suffer, and thus lianas are predicted to increase in relative abundance in seasonal tropical forests