A high solids field-to-fuel research pipeline to identify interactions between feedstocks and biofuel production

Background Environmental factors, such as weather extremes, have the potential to cause adverse effects on plant biomass quality and quantity. Beyond adversely affecting feedstock yield and composition, which have been extensively studied, environmental factors can have detrimental effects on saccharification and fermentation processes in biofuel production. Only a few studies have evaluated the effect of these factors on biomass deconstruction into biofuel and resulting fuel yields. This field-to-fuel evaluation of various feedstocks requires rigorous coordination of pretreatment, enzymatic hydrolysis, and fermentation experiments. A large number of biomass samples, often in limited quantity, are needed to thoroughly understand the effect of environmental conditions on biofuel production. This requires greater processing and analytical throughput of industrially relevant, high solids loading hydrolysates for fermentation, and led to the need for a laboratory-scale high solids experimentation platform. Results A field-to-fuel platform was developed to provide sufficient volumes of high solids loading enzymatic hydrolysate for fermentation. AFEX pretreatment was conducted in custom pretreatment reactors, followed by high solids enzymatic hydrolysis. To accommodate enzymatic hydrolysis of multiple samples, roller bottles were used to overcome the bottlenecks of mixing and reduced sugar yields at high solids loading, while allowing greater sample throughput than possible in bioreactors. The roller bottle method provided 42–47% greater liquefaction compared to the batch shake flask method for the same solids loading. In fermentation experiments, hydrolysates from roller bottles were fermented more rapidly, with greater xylose consumption, but lower final ethanol yields and CO2 production than hydrolysates generated with shake flasks. The entire platform was tested and was able to replicate patterns of fermentation inhibition previously observed for experiments conducted in larger-scale reactors and bioreactors, showing divergent fermentation patterns for drought and normal year switchgrass hydrolysates. Conclusion A pipeline of small-scale AFEX pretreatment and roller bottle enzymatic hydrolysis was able to provide adequate quantities of hydrolysate for respirometer fermentation experiments and was able to overcome hydrolysis bottlenecks at high solids loading by obtaining greater liquefaction compared to batch shake flask hydrolysis. Thus, the roller bottle method can be effectively utilized to compare divergent feedstocks and diverse process conditions.

Selection of Sorbent for Poliovirus Vaccine Strain Concentrate Purification by Gel Filtration

In the production of anti-virus vaccines, the replacement of wild-type with attenuated strains is becoming relevant. Sabin strains are the most suitable candidates for this replacement in the production of inactivated poliovirus vaccines. The main problem in the development of methods for purification of viral particles of Sabin strains is the preservation of their stability and antigenic properties. We have compared the sorbents used for gel-filtration of poliovirus concentrates and have selected a chromatographic resin, Sephacryl S-300HR, which provides a high yield of the target product and its high purity both during cultivation in roller bottles and in bioreactors. It was also shown that, along with effective purification, Sephacryl S-300HR allows preservation of the polyovirus antigenic properties and can be used in the preparation of monovalent inactivated poliovirus concentrates that meet the good quality requirements. inactivated polio vaccine (IPV), oral polio vaccine (OPV), poliomyelitis, chromatographic purification, gel filtration The authors grateful to L.P. Antonova and A.A. Butusova for their assistance in conducting the research.

Shearing Flows around Cylinders and Spheres

Novel flows between rotating cylinders, of materials settling in tubes, and in roller bottles are described. Low speed flow around a sphere is derived, and paradoxical settling behaviors are mentioned, including the effects of red blood cells. Stokes drift and Magnus force on falling bodies near boundaries. A first example from scientific ethics is raised. The streamfunction and biharmonic equation are derived and applied to flow past a sphere.

In Vitro Large-Scale Cultivation and Evaluation of Microencapsulated Immortalized Human Hepatocytes (HepLL) in Roller Bottles

Background/Aims Microencapsulated hepatocytes have been proposed as promising bioactive agents for packed-bed or fluidized-bed bioartificial liver assist devices (BLADs) and for hepatocyte transplantation because of the potential advantages they offer of high mass transport rate and an optimal microenvironment for hepatocyte culture. We developed a large-scale and high-production alginate-chitosan (AC) microcapsule roller bottle culture system for the encapsulation of HepLL immortalized human hepatocytes. In this study, the efficacy of upscaling encapsulated HepLL cells production with roller bottle cultivation was evaluated in vitro. Methods Microencapsulated HepLL cells were grown at high yield in large-scale roller bottles, with free cells cultured in roller bottle spinners serving as controls. The mechanical stability and the permeability of the AC microcapsules were investigated, and the growth, metabolism and functions of the encapsulated HepLL cells were evaluated as compared to free cells. Results The microcapsules withstood well the shear stress induced by high agitation rates. The microcapsules were permeable to albumin, but prevented the release of immunoglobulins. Culture in roller bottles of immortalized human hepatocytes immobilized in the AC microcapsules improved cell growth, albumin synthesis, ammonia elimination and lidocaine clearance as compared with free cells cultured in roller bottles. Conclusions Encapsulated HepLL cells may be cultured on a large scale in roller bottles. This makes them possible candidates for use in cell-based liver assist therapies.