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191.
Dr. Christian Hakemeyer Ulrike Strauss Silke Werz Francisca Folque Jose C. Menezes 《Biotechnology journal》2013,8(7):835-846
In biomanufacturing processes, the influence of feedstock components on product yield and quality is considerable and often poorly understood. Here we describe the capabilities of near-infrared spectroscopy (NIRS) and two dimensional (2D)-fluorescence spectroscopy in detecting chemical changes over time in two types of culture media (one basal media and one feed media) used in the production of monoclonal antibodies (mAbs) by Chinese hamster ovary (CHO) cells. Both spectroscopies were able to detect compositional changes in basal media over storage period of 12 weeks. NIRS was more effective in detecting changes in feed medium composition. The impact of storage time in process performance was evaluated by using aged media components in mAb cultivations. The study suggests that basal media aging results in a decrease of the integral of viable cells (IVC) (cell growth over time), while product titer is not significantly affected. Feed media appears to be less sensitive to storage and no correlation between the age of the media and cell culture performance was detected. Results obtained provide a basis on which to further improve cell culture raw material quality assessment using vibrational (e.g. NIRS) and optical (e.g. 2D-fluorescence) spectroscopic methods. 相似文献
192.
Maya Almaraz Maegen Simmonds F. Garrett Boudinot Alan V. Di Vittorio Nina Bingham Sat Darshan S. Khalsa Steven Ostoja Kate Scow Andrew Jones Iris Holzer Erin Manaigo Emily Geoghegan Heath Goertzen Whendee L. Silver 《Global Change Biology》2023,29(21):5988-5998
The ongoing climate crisis merits an urgent need to devise management approaches and new technologies to reduce atmospheric greenhouse gas concentrations (GHG) in the near term. However, each year that GHG concentrations continue to rise, pressure mounts to develop and deploy atmospheric CO2 removal pathways as a complement to, and not replacement for, emissions reductions. Soil carbon sequestration (SCS) practices in working lands provide a low-tech and cost-effective means for removing CO2 from the atmosphere while also delivering co-benefits to people and ecosystems. Our model estimates suggest that, assuming additive effects, the technical potential of combined SCS practices can provide 30%–70% of the carbon removal required by the Paris Climate Agreement if applied to 25%–50% of the available global land area, respectively. Atmospheric CO2 drawdown via SCS has the potential to last decades to centuries, although more research is needed to determine the long-term viability at scale and the durability of the carbon stored. Regardless of these research needs, we argue that SCS can at least serve as a bridging technology, reducing atmospheric CO2 in the short term while energy and transportation systems adapt to a low-C economy. Soil C sequestration in working lands holds promise as a climate change mitigation tool, but the current rate of implementation remains too slow to make significant progress toward global emissions goals by 2050. Outreach and education, methodology development for C offset registries, improved access to materials and supplies, and improved research networks are needed to accelerate the rate of SCS practice implementation. Herein, we present an argument for the immediate adoption of SCS practices in working lands and recommendations for improved implementation. 相似文献
193.
Summary The effect of organic amendments (cow manure and green manure) on monthly variations of soluble P in a volcanic-ash-derived soil was studied. Soluble P (Truog's method) showed minimums at the beginning of August and at the beginning of January. Cow manure produced a remarkable increase of soluble P and removed the January minimum. In soils treated with legume green manure, soluble SP markedly decreased during the first and second month. Data for organic P suggested that the summer decreases of soluble P were partly due to microbial immobilization. In soil treated with mineral fertilizers only, more than half of the P added as superphosphate was found as Al and Fe phosphate after one month. Organic amendments, especially cow manure, decreased the immobilization of superphosphate P. 相似文献
194.
D. V. Guebel A. Cordenons B. C. Nudel A. M. Giulietti 《Journal of industrial microbiology & biotechnology》1991,7(4):287-291
Summary The optimization of ethanol production byPichia stipitis NRRL Y-7124 was analysed by ATP balance. Ethanol volumetric productivity was maximal (0.5–0.6 g/l h) only over a narrow range of oxygen transfer rates (3–5 mmol O2/l h). Trace element supplements increased ethanol volumetric productivity 20%. Biotin and thiamine did not significantly affect ethanol yield. Vitamins and trace elements were not synergistic. Organic nitrogen source from yeast extract was used for growth simultaneously to ammonia. 相似文献
195.
A detailed method for the formulation of titanium(III) nitrilotriacetate, a sulfur-free, media reductant, is described. Growth of Butyribacterium methylotrophicum on methanol was not significantly inhibited by 5 mM titanium(III) nitrilotriacetate. Concentrations as low as 30 μM effectively reduced cultured media and allowed growth of this obligate anaerobe. This reductant was used to investigate the nutritional requirements for sulfur compounds and growth of fastidious anaerobes in continuous flow culture. 相似文献
196.
D. Gareth Rees Igor I. Gerashchenko Elena V. Kudryashova Vadim V. Mozhaev Peter J. Halling 《Biocatalysis and Biotransformation》2013,31(3):161-166
Amino groups in alpha-chymotrypsin were reacted with pyromellitic anhydride, introducing 17 to 32 additional carboxyl groups. This modification causes a major change in the water adsorption isotherm of the lyophilized protein powder. Little water is bound by the modified enzyme at water activity (aw) below 0.35, but it shows increased water binding at aw over 0.5. This correlates with a similar change in the aw dependence of the catalytic activity of the enzyme powder suspended in hexane, with a much steeper increase in activity of the modified chymotrypsin. 相似文献
197.
Melakeberhan H 《Journal of nematology》2010,42(1):73-77
Preventive and/or manipulative practices will be needed to maintain soil's biological, physiochemical, nutritional, and structural health in natural, managed, and disturbed ecosystems as a foundation for food security and global ecosystem sustainability. While there is a substantial body of interdisciplinary science on understanding function and structure of soil ecosystems, key gaps must be bridged in assessing integrated agro-biological, ecological, economical, and environmental efficiency of soil manipulation practices in time and space across ecosystems. This presentation discusses the application of a fertilizer use efficiency (FUE) model for assessing agronomic, economic, ecological, environmental, and nematode (pest) management efficiency of soil amendments. FUE is defined as increase in host productivity and/or decrease in plant-parasitic nematode population density in response to a given fertilizer treatment. Using the effects of nutrient amendment on Heterodera glycines population density and normalized difference vegetative index (indicator of physiological activities) of a soybean cultivar 'CX 252', how the FUE model recognizes variable responses and separates nutrient deficiency and toxicity from nematode parasitism as well as suitability of treatments designed to achieve desired biological and physiochemical soil health conditions is demonstrated. As part of bridging gaps between agricultural and ecological approaches to integrated understanding and management of soil health, modifications of the FUE model for analyzing the relationships amongst nematode community structure, soil parameters (eg. pH, nutrients, %OM), and plant response to soil amendment is discussed. 相似文献