V. Baleš

Bio: V. Baleš is an academic researcher from Slovak University of Technology in Bratislava. The author has contributed to research in topics: Aspergillus niger & Gluconic acid. The author has an hindex of 5, co-authored 5 publications receiving 246 citations.

A Kinetic Model for Gluconic Acid Production by Aspergillus niger

Abstract: Fermentation kinetics of gluconic acid production by Aspergillus niger was studied in a batch system. The dependence of the specific growth rate on carbon and oxygen substrates was assumed to follow either the Monod or Contois kinetic model. The simulation results revealed that for predicting the fermentation process of gluconic acid production by A. niger, the Contois typemodel was more suitable than that based on the Monod equation. The Luedeking|Piret equation was proposed for gluconic acid production and an equation considering the cell maintenance for glucose and dissolved oxygen consumption. Estimated parameters of this model indicate that the production of gluconic acid was mostly growth-associated.

Gluconic Acid: Properties, Applications and Microbial Production

Abstract: Summary Gluconic acid is a mild organic acid derived from glucose by a simple oxidation reaction. The reaction is facilitated by the enzyme glucose oxidase (fungi) and glucose dehydrogenase (bacteria such as Gluconobacter). Microbial production of gluconic acid is the preferred method and it dates back to several decades. The most studied and widely used fermentation process involves the fungus Aspergillus niger. Gluconic acid and its derivatives, the principal being sodium gluconate, have wide applications in food and pharmaceutical industry. This article gives a review of microbial gluconic acid production, its properties and applications.

Practical experiences from the development of aqueous two‐phase processes for the recovery of high value biological products

Abstract: The development of recovery processes using aqueous two-phase systems (ATPS) has been limited by the extensive experimental work required to establish the optimal system parameters to ensure selective partitioning of the product of interest. Although using full factorial experiments has been demonstrated to be an effective strategy for the characterization of the partitioning behaviour of biological products in ATPS, this approach is characterized by its costly and time consuming nature. As an alternative, the use of a robotic-aided strategy has been proposed. However, the need for high cost equipment may limit the generic implementation of this strategy. Based on practical experience using ATPS, practical strategies for the predictive design of primary recovery processes using polymer–salt systems were derived. To evaluate the generic application of the proposed strategies, four experimental models (B-phycoerythrin, C-phycocyanin, double layered rotavirus-like particles and lutein) were selected. The application of these strategies resulted in the development of simplified recovery processes for the selected experimental models. The practical review presented is considered a relevant contribution that will provide general rules to facilitate the establishment of ATPS processes, particularly for new researchers in the field. Copyright © 2007 Society of Chemical Industry

Biotechnological production of gluconic acid: future implications

Abstract: Gluconic acid (GA) is a multifunctional carbonic acid regarded as a bulk chemical in the food, feed, beverage, textile, pharmaceutical, and construction industries. The favored production process is submerged fermentation by Aspergillus niger utilizing glucose as a major carbohydrate source, which accompanied product yield of 98%. However, use of GA and its derivatives is currently restricted because of high prices: about US$ 1.20–8.50/kg. Advancements in biotechnology such as screening of microorganisms, immobilization techniques, and modifications in fermentation process for continuous fermentation, including genetic engineering programmes, could lead to cost-effective production of GA. Among alternative carbohydrate sources, sugarcane molasses, grape must show highest GA yield of 95.8%, and banana must may assist reducing the overall cost of GA production. These methodologies would open new markets and increase applications of GA.