Bioprocess

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

Activity determination of an algal-bacterial consortium developed during wastewater treatment based on oxygen evolution

Abstract: Microalgae culture is an environmentally friendly alternative to the energy consuming activated sludge technology used for wastewater treatment. Since the bioprocess is driven by sunlight, the operational costs are considerably reduced compared to the mechanical aeration. Before implementing extensively, this bioprocess still requires a better understanding of the organism interactions and the impact exerted by the main variable ruling the process (light intensity). For this purpose, oxygen concentration evolution was studied and modelled in a consortia developed during the treatment of domestic wastewater. Rates of oxygenation were studied and modelled with the equations validated for microalgae cultures. The bacterial activity was simulated by means of equations used for quantification of oxygen consumption in conventional wastewater treatment facilities. Analysis revealed important aspects of the symbiosis: while bacterial oxygen consumption was limited to a few hours after the addition of wastewater, microalgae not only act as oxygen producer, events of photorespiration and endogenous respiration processes were detected along the continuous culture treating wastewater.

Perspectives and new directions for bioprocess optimization using Zymomonas mobilis in the ethanol production

Abstract: Zymomonas mobilis is an ethanologenic microbe that has a demonstrated potential for use in lignocellulosic biorefineries for bioethanol production. Z. mobilis exhibits a number of desirable characteristics for use as an ethanologenic microbe, with capabilities for metabolic engineering and bioprocess modification. Many advanced genetic tools, including mutation techniques, screening methods and genome editing have been successively performed to improve various Z. mobilis strains as potential consolidated ethanologenic microbes. Many bioprocess strategies have also been applied to this organism for bioethanol production. Z. mobilis biofilm reactors have been modified with various benefits, including high bacterial populations, less fermentation times, high productivity, high cell stability, resistance to the high concentration of substrates and toxicity, and higher product recovery. We suggest that Z. mobilis biofilm reactors could be used in bioethanol production using lignocellulosic substrates under batch, continuous and repeated batch processes.

Development of a Bioprocess for the Production of Cyclic Lipopeptides Pseudofactins With Efficient Purification From Collected Foam.

Abstract: Microbial surfactants (biosurfactants) have gained interest as promising substitutes of synthetic surface-active compounds. However, their production and purification are still challenging, with significant room for efficiency and costs optimization. In this work, we introduce a method for the enhanced production and purification of cyclic lipopeptides pseudofactins (PFs) from Pseudomonas fluorescens BD5 cultures. The method is directly applicable in a technical scale with the possibility of further upscaling. Comparing to the original protocol for production of PFs (cultures in mineral salt medium in shaken flasks followed by solvent-solvent extraction of PFs), our process offers not only ∼24-fold increased productivity, but also easier and more efficient purification. The new process combines high yield of PFs (∼7.2 grams of PFs per 30 L of working volume), with recovery levels of 80-90% and purity of raw PFs up to 60-70%. These were achieved with an innovative, single-step thermal co-precipitation and extraction of PFs directly from collected foam, as a large amount of PF-enriched foam was produced during the bioprocess. Besides we present a protocol for the selective production of PF structural analogs and their separation with high-performance liquid chromatography. Our approach can be potentially utilized in the efficient production and purification of other lipopeptides of Pseudomonas and Bacillus origin.