Bioprocess

About: Bioprocess is a research topic. Over the lifetime, 2219 publications have been published within this topic receiving 50972 citations.

Immobilization of proline-specific endoprotease on nonporous silica nanoparticles functionalized with amino group, Bioprocess and Biosystems Engineering

Abstract: Enzyme immobilization is believed to provide an excellent base for increasing environmental tolerance of enzyme and considerable period of time. In this work, a kind of nonporous silica nanoparticles functionalized with amino group was synthesized to immobilize proline-specific endoprotease (PSEP). PSEP is known to specifically cleave peptides (or esters) at the carboxyl side of proline, thus can prevent the formation of haze and prolong the shelf life of beer. After immobilization, the environmental tolerance (temperature and pH, respectively) was obviously improved, and the immobilized enzyme can retain above 90 % of its original activity after 6 uses. Moreover, the immobilized enzyme can effectively prevent the formation of chill-haze using fresh beer fermentation liquid.

Lignocellulosic Ethanol: Feedstocks and Bioprocessing

Abstract: Lignocellulosic biomass (LCB) from various sources, including agriculture, industries, forestry, and municipalities has the promising potential for the production of bioethanol. However, the recalcitrant nature of this complex biomass can be overpowered by several pretreatment techniques for increasing the accessibility of the hydrolytic enzymes to produce fermentable sugars. Apart from the recalcitrance of LCB, another challenge is potential ethanologen, which aid in high ethanol yield. The current technologies in use suffer with various drawbacks including low ethanol yield, ethanol productivity, cofermentation of pentose and hexose sugars, reduced tolerance to product and inhibitors. Herein, we discuss availability of feedstocks, various pretreatment and bioprocesses, critical factors affecting bioprocesses, and feasibility of the processes at industrial scale. Along with pretreatment, stress has been laid on the ethanologens, which could facilitate ethanol fermentation at high temperatures with the possibility of overcoming the challenges for the development of economical bioprocess.

The industrial versatility of Gluconobacter oxydans: current applications and future perspectives

Abstract: Gluconobacter oxydans is a well-known acetic acid bacterium that has long been applied in the biotechnological industry. Its extraordinary capacity to oxidize a variety of sugars, polyols, and alcohols into acids, aldehydes, and ketones is advantageous for the production of valuable compounds. Relevant G. oxydans industrial applications are in the manufacture of L-ascorbic acid (vitamin C), miglitol, gluconic acid and its derivatives, and dihydroxyacetone. Increasing efforts on improving these processes have been made in the last few years, especially by applying metabolic engineering. Thereby, a series of genes have been targeted to construct powerful recombinant strains to be used in optimized fermentation. Furthermore, low-cost feedstocks, mostly agro-industrial wastes or byproducts, have been investigated, to reduce processing costs and improve the sustainability of G. oxydans bioprocess. Nonetheless, further research is required mainly to make these raw materials feasible at the industrial scale. The current shortage of suitable genetic tools for metabolic engineering modifications in G. oxydans is another challenge to be overcome. This paper aims to give an overview of the most relevant industrial G. oxydans processes and the current strategies developed for their improvement.

Recirculating bioreactor–separator system for simultaneous biotransformation and recovery of product: Immobilized L-aspartate β-decarboxylase reactor system

Abstract: A new combined bioreactor-separator system was designed and its operational feasibility demonstrated in order to develop a bioprocess that enables us to handle simultaneous biotransformation and recovery of product by crystallization. Enzymatic conversion of L-aspartate to L-alanine by L-aspartate β-decarboxylase from Pseudomonas dacunhae (ATCC 21192) was used as a model system for this study to demonstrate the principles involved in the bioprocess design. Immobilized cells of P. dacunhae containing the enzyme were fluidized in a tapered column type of bioreactor and a filter-crystallizer combination was used as a separator unit in our experimental system. It was found that almost a theoretical yield was achieved, and the process control for both the bioreactor operation and separation was relatively easy. The Production systems, namely, the recirculating bioreactor separator combination system and the conventional batch reactor system, were analyzed and compared based on the results obtained form this study, and it was found that a significant cost reduction, by about 20%, can be achieved when the recirculating bioreactor–separator combination system was employed. Based on these findings, it is anticipated that the conceptual design of the bioreactor–separator combination system evaluated in this study has some potential for industrial application.