Two-Step Purification of L-Asparaginase from Acrylaway® L

Abstract L-Asparaginase (L-ASNase) is a biopharmaceutical used for acute lymphoblastic leukaemia (ALL) treatment, dramatically increasing the patients' chance of cure. However, its production and distribution in developing countries were disrupted because of its low profitability, which caused great concern among patients. This study evaluates the feasibility of combining fractional precipitation and aqueous two-phase systems (ATPS) to purify L-ASNase from a low-grade product, commercially known as Acrylaway® L. The ATPS purification results were not particularly expressive compared to the two-step purification process composed of ethanol precipitation and gel filtration, which was able to recover the target molecule with a purification factor over 5 fold. Thus, we studied a purification process capable of manufacturing pharmaceutical grade L-ASNase from a commercially available low-grade raw material; however, improvements regarding its throughput must be achieved, and high purity is the first step to apply it as a new biopharmaceutical product. The proposed process could pose as a short-time solution to mitigate its shortage while a cost-effective production plant is being developed.

Advances in the synthesis of biobutanol by consolidated bioprocessing from lignocellulose / 生物工程学报

Consolidated bioprocessing (CBP) is a multi-step process in a bioreactor, which completes hydrolase production, enzymatic hydrolysis, and microbial fermentation. It is considered to be the most promising process for the production of second-generation biofuels because of its simple steps and low cost. Due to the complexity of lignocellulose degradation and the butanol synthesis pathway, few wild microorganisms can directly utilize lignocellulose to synthesize butanol. With the development of synthetic biology, single-bacterium directly synthesizes butanol using lignocellulose by introducing a butanol synthesis pathway in the cellulolytic Clostridium. However, there are still some problems such as heavy metabolic load of single bacterium and low butanol yield. Co-culture can relieve the metabolic burden of single bacterium through the division of labor in different strains and can further improve the efficiency of butanol synthesis. This review analyzes the recent research progress in the synthesis of biobutanol using lignocellulose by consolidated bioprocessing from both the single-bacterium strategy and co-culture strategy, to provide a reference for the research of butanol and other biofuels.

High-density culture of Vero cells in novel perfusion bioreactor system

Viruses are the obligatory intracellular parasites infecting microbes, plants, animals, and humans. They aredead outside host cell but can take-over the host’s cell machinery as soon as they are into it. Several studies oninhibitor compounds have been done for animal viruses including those that are affecting humans, but thereis inadequacy in terms of research and literature for plant viruses that are responsible for losses in crop yieldand quality loss all across the globe. This could be focal point to study plant viruses, their transmission andpathogenicity, and to establish widely used, effective, and advanced approaches for their control. The purposeof this review is to discuss various approaches to control plant viruses that have been developed and applied tocombat plant viral infections. We have divided these approaches into two categories conventional (meristemtip culture, cryotherapy, thermotherapy, and chemotherapy) and advanced (nucleic acid-based approacheslike RNA Silencing, cross-protection, transgenic plants, gene pyramiding, and protein-protein interaction).Moreover, we have discussed and compared the principles, methodologies, advantages, and disadvantages ofeach technique. The approaches have been explored to promote their application in best suited way on variousplants to control viral diseases and to improve food crops quality with increase in production.

Effects of agitation and exogenous H2 on bioconversion of sugarcane bagasse into ethanol by Clostridium thermocellum ATCC 27405

Background: The production of ethanol by a Consolidated Bioprocessing (CBP) strategy, which simultaneously combines cellulase production, lignocellulosic biomass hydrolysis and fermentation of released sugars to ethanol in one bioreactor, is a promising technology for cost reduction in the biological processing of biomass, specially using agroindustrial residues. Clostridium thermocellum is an anaerobic, thermophilic, strictly fermentative gram positive bacterium that meets all the requirements for CBP. Results: Ethanol concentration obtained in the non-stirred fermentation process in flasks with raw bagasse was two times greater than that in the stirred system. The results observed using a pretreated sugarcane bagasse in non-stirred flasks regarding ethanol concentration, were slightly lower than with raw bagasse. The sparging of exogenous H2 into the medium at atmospheric pressure inside the bioreactor showed to be unfavourable to achieve higher ethanol yields. Conclusions: The strain investigated is a promising candidate for thermophilic fermentative ethanol production from dried ground raw sugarcane bagasse in a CBP strategy, although the alcohol concentrations need to be further improved. In future studies, it is recommended to investigate different modes of operation of the fermentation process, including pressurized conditions, as well as to use wet raw sugarcane bagasse aiming to achieve additional improvement in ethanol production and to reduce the costs of the process.

Purification, Characterization and Application of Polygalacturonase from Aspergillus niger CSTRF

Aims: The research was carried out to study the purification, characterization and application of polygalacturonase from Aspergillus niger CSTRF. Methodology and Results: The polygalacturonase (PG) from the fungus was purified by ammonium sulphate precipitation and dialysed. The resulting fraction of the enzyme was further separated by molecular exclusion and ion exchange chromatography. The enzyme was purified 28.19 fold with a yield of approximately 69 % following purification with SP C-50. It has a relative molecular weight of 79,430 daltons and markedly influenced by temperature, pH and substrate concentrations of reactions with optimum activity at 35 °C, pH 4.0 and 8 mg/mL respectively. The PG was heat stable over a broad range of temperatures. Line weaver-Burk plot for the apparent hydrolysis of pectin showed approximately Km value of 2.7 mg/mL. The activity of the enzyme was enhanced by Na+, Ca2+, Mg2+ and Zn2+, while EDTA, PbCl2, HgCl2 and IAA were inhibitory. The ability of the purified enzyme to clarify fruit juice was also investigated. Conclusion, significance and impact of the study: This study revealed that polygalacturonase possesses properties for clarification of fruit juice and by extension bioprocessing applications.