Modulation of starch-based film properties for encapsulation of microbial inoculant.

Controlled release of beneficial microorganisms in agriculture by encapsulation in biopolymeric matrices can improve biofertilizer efficacy, but it requires the modulation of properties to ensure more efficient and predictable release patterns. This study investigated the effect of a starch-based system to protect and release Priestia megaterium (former Bacillus megaterium) processed as films modified with potential cell-protective additives (maltodextrin, cellulose, and bentonite). The release kinetics, physicochemical and morphological film characteristics, and their protection against UV (Ultraviolet) radiation and temperature were evaluated.

Effect of impeller type on cellular morphology and production of clavulanic acid by Streptomyces clavuligerus.

It is essential to evaluate the effects of operating conditions in submerged cultures of filamentous microorganisms. In particular, the impeller type influences the flow pattern, power consumption, and energy dissipation, leading to differences in the hydrodynamic environment that affect the morphology of the microorganism. This work investigated the effect of different impeller types, namely the Rushton turbine (RT-RT) and Elephant Ear impellers in up-pumping (EEUP) and down-pumping (EEDP) modes, on cellular morphology and clavulanic acid (CA) production by Streptomyces clavuligerus in a stirred-tank bioreactor.

Red biocolorant from endophytic Talaromyces minnesotensis: production, properties, and potential applications.

Fungal colorants are gradually entering the global color market, given their advantages of being less harmful to human health, as well as having greater stability and biotechnological potential, compared to other natural sources. The present work concerns the isolation and identification of an endophytic filamentous fungus, together with the chemical characterization and assessment of the fluorescence, toxicity, stability, and application potential of its synthesized red colorant. The endophytic fungus was isolated from Hymenaea courbaril, a tree from the Brazilian savannah, and was identified as Talaromyces minnesotensis by phenotypic and genotypic characterization.

Exploring the roles of starch for microbial encapsulation through a systematic mapping review.

Microorganism encapsulation protects them from stressful conditions and assists in maintaining their viability, being especially beneficial when the carrier material is a renewable and biodegradable biopolymer, such as starch. Here, a systematic mapping was performed to provide a current overview on the use of starch-based systems for microbial encapsulation. Following well-established guidelines, a systematic mapping was conducted and the following could be drawn: 1) there was a significant increase in publications on microbial encapsulation using starch over the past decade, showing interest from the scientific community, 2) ionotropic gelation, emulsification and spray drying are the most commonly used techniques for starch-based microbial encapsulation, and 3) starch play important functions in the encapsulation matrix such as assisting in the survival of the microorganisms.

Mathematical Modeling of Fed-Batch Ethanol Fermentation Under Very High Gravity and High Cell Density at Different Temperatures.

The use of more appropriate kinetic models can assist in improving ethanol fermentation under conditions of very high gravity (VHG) and high cell density (HCD), in order to obtain higher amounts of ethanol in the broth combined with high productivity. The aim of this study was to model fed-batch ethanol fermentation under VHG/HCD conditions, at different temperatures, considering three types of inhibition (substrate, ethanol, and cells). Fermentations were carried out using different temperatures (28 ≤ [Formula: see text] (°C) ≤ 34), inoculum sizes (50 ≤ [Formula: see text] (g L) ≤ 125), and substrate concentrations in the must (258 ≤ [Formula: see text] (g L) ≤ 436).

Ethanol yield calculations in biorefineries.

The ethanol yield on sugar during alcoholic fermentation allows for diverse interpretation in academia and industry. There are several different ways to calculate this parameter, which is the most important one in this industrial bioprocess and the one that should be maximized, as reported by Pereira, Rodrigues, Sonego, Cruz and Badino (A new methodology to calculate the ethanol fermentation efficiency at bench and industrial scales. Ind Eng Chem Res 2018; 57: 16182-91).

Cellulolytic enzymes production guided by morphology engineering.

Endoglucanase and xylanase are critical enzymes for liquefaction and enzyme hydrolysis of high solids lignocellulosic biomass to facilitate its transport and production of desired derived products. Here is reported how combinations of different spore concentrations and pH influence microbial morphology, and how this may be used to direct expression and secretion of enzymes by Aspergillus niger. While xylanase production is not affected by A.

Improvement of ethanol production by extractive fed-batch fermentation in a drop column bioreactor.

The use of fed-batch extractive fermentation can overcome inhibitory effects caused by the substrate and ethanol to the yeast cells, since it allows regulate the substrate concentration and remove the product as it is produced. The present study describes the modelling and experimental validation of ethanol production in fed-batch extractive fermentation with in situ ethanol removal by oleic acid in a non-conventional drop column bioreactor (DCB) operated under industrial conditions. The model developed using the hybrid Andrews-Levenspiel equation and ethanol distribution coefficient parameter (K) provided an excellent description of the fed-batch extractive ethanol fermentation process with oleic acid.

Relation between pellet fragmentation kinetics and cellulolytic enzymes production by Aspergillus niger in conventional bioreactor with different impellers.

The hydrodynamic environment in bioreactors affects the oxygen transfer rate and the shear conditions during microbial cultivations. Therefore, assessment of the effect of the hydrodynamic environment on cellular morphology can contribute to favoring the production of metabolites of interest. The aim of this work was to use image analysis in order to quantify the fragmentation of Aspergillus niger pellets in a conventional bioreactor operated using different impeller speeds, air flow rates, and impeller configurations including Rushton turbines and Elephant Ear impellers, with evaluation of the influence of the hydrodynamic environment on the production of cellulolytic enzymes.

Anthraquinone encapsulation into polymeric nanocapsules as a new drug from biotechnological origin designed for photodynamic therapy.

Photodynamic therapy has been applied for the treatment of many diseases, especially skin diseases. However, poor aqueous solubility and toxicity of some photosensitizer drugs are the main disadvantages for their direct clinical applications. Thus, biotechnology and nanotechnology are important tools in the development of new ways of obtaining photoactive compounds that are biocompatible.

Average shear rate in airlift bioreactors: searching for the true value.

The shear rate is an important bioreactor parameter that needs to be evaluated due to its impact on microorganism morphology and viability, and consequently on bioproduct formation. Airlift bioreactors, classified as low-shear devices, are used as an alternative to conventional stirred-tank reactors. Considerable efforts have been made to characterize the shear environments in airlift bioreactors, using the average shear rate ([Formula: see text]) as a key parameter.

On-Site Production of Cellulolytic Enzymes by the Sequential Cultivation Method.

The conversion of renewable lignocellulosic biomass into fuels, chemicals, and high-value materials using the biochemical platform has been considered the most sustainable alternative for the implementation of future biorefineries. However, the high cost of the cellulolytic enzymatic cocktails used in the saccharification step significantly affects the economics of industrial large-scale conversion processes. The on-site production of enzymes, integrated to the biorefinery plant, is being considered as a potential strategy that could be used to reduce costs.

Screening of medium constituents for clavulanic acid production by Streptomyces clavuligerus.

Clavulanic acid is a β-lactam compound with potent inhibitory activity against β-lactamases. Studies have shown that certain amino acids play essential roles in CA biosynthesis. However, quantitative evaluations of the effects of these amino acids are still needed in order to improve CA production.

A closed-loop strategy for endoglucanase production using sugarcane bagasse liquefied by a home-made enzymatic cocktail.

Use of the same lignocellulosic biomass as feedstock for enzymes and ethanol production has been suggested as a lower cost option in future biorefineries. Here, we propose a closed-loop strategy to produce the cellulolytic enzymes required for biomass hydrolysis using sugarcane bagasse liquefied by a home-made enzymatic cocktail as carbon source and inducer. The fed-batch liquefaction conditions were firstly evaluated using commercial enzymes.

Soybean protein as a cost-effective lignin-blocking additive for the saccharification of sugarcane bagasse.

Addition of surfactants, polymers, and non-catalytic proteins can improve the enzymatic hydrolysis of lignocellulosic materials by blocking the exposed lignin surfaces, but involves extra expense. Here, soybean protein, one of the cheapest proteins available, was evaluated as an alternative additive for the enzymatic hydrolysis of pretreated sugarcane bagasse. The effect of the enzyme source was investigated using enzymatic cocktails from A.

Secretome data from Trichoderma reesei and Aspergillus niger cultivated in submerged and sequential fermentation methods.

The cultivation procedure and the fungal strain applied for enzyme production may influence levels and profile of the proteins produced. The proteomic analysis data presented here provide critical information to compare proteins secreted by Trichoderma reesei and Aspergillus niger when cultivated through submerged and sequential fermentation processes, using steam-explosion sugarcane bagasse as inducer for enzyme production. The proteins were organized according to the families described in CAZy database as cellulases, hemicellulases, proteases/peptidases, cell-wall-protein, lipases, others (catalase, esterase, etc.

Secretome analysis of Trichoderma reesei and Aspergillus niger cultivated by submerged and sequential fermentation processes: Enzyme production for sugarcane bagasse hydrolysis.

Cellulases and hemicellulases from Trichoderma reesei and Aspergillus niger have been shown to be powerful enzymes for biomass conversion to sugars, but the production costs are still relatively high for commercial application. The choice of an effective microbial cultivation process employed for enzyme production is important, since it may affect titers and the profile of protein secretion. We used proteomic analysis to characterize the secretome of T.

Power consumption evaluation of different fed-batch strategies for enzymatic hydrolysis of sugarcane bagasse.

The minimization of costs in the distillation step of lignocellulosic ethanol production requires the use of a high solids loading during the enzymatic hydrolysis to obtain a more concentrated glucose liquor. However, this increase in biomass can lead to problems including increased mass and heat transfer resistance, decreased cellulose conversion, and increased apparent viscosity with the associated increase in power consumption. The use of fed-batch operation offers a promising way to circumvent these problems.

Mixing design for enzymatic hydrolysis of sugarcane bagasse: methodology for selection of impeller configuration.

One of the major process bottlenecks for viable industrial production of second generation ethanol is related with technical-economic difficulties in the hydrolysis step. The development of a methodology to choose the best configuration of impellers towards improving mass transfer and hydrolysis yield together with a low power consumption is important to make the process cost-effective. In this work, four dual impeller configurations (DICs) were evaluated during hydrolysis of sugarcane bagasse (SCB) experiments in a stirred tank reactor (3 L).

Unusual 2(1H)-pyrazinones isolated from a culture of a Brazilian marine-derived Streptomyces sp.

Four new secondary metabolites, giovaninones A-D (1-4), were isolated from an ethyl acetate extract of a culture of a marine-derived Streptomyces strain designated SS99BA-2. Chemical analysis was completely conducted in a coupled automated LC-SPE system with the use of a cryogenic NMR probehead and HRMS. The application of this system to identify, purify and elucidate all the structures is described.

Oxygen transfer in a pressurized airlift bioreactor.

Airlift bioreactors (ALBs) offer advantages over conventional systems, such as simplicity of construction, reduced risk of contamination, and efficient gas-liquid dispersion with low power consumption. ALBs are usually operated under atmospheric pressure. However, in bioprocesses with high oxygen demand, such as high cell density cultures, oxygen limitation may occur even when operating with high superficial gas velocity and air enriched with oxygen.

Preliminary studies for cephamycin C purification technique.

A study was made for purification of cephamycin C from fermentation of Streptomyces clavuligerus. Initially, the culture broth was clarified by microfiltration and ultrafiltration, after which the resulting permeates were subjected to nonspecific adsorption and ion-exchange chromatography on resin columns. The antibiotic activity was measured by the biological method at each stage by assaying its activity against the Escherichia coli ESS, super sensitive to β-lactam antibiotic.

Average shear rate in three pneumatic bioreactors.

A method proposed in recent literature was applied to evaluate the average shear rate (γav) in three pneumatic bioreactors of 5-dm3 working volume: bubble column, split airlift, and concentric-tube airlift. The volumetric oxygen transfer coefficient (k(L) a) is the appropriate characteristic parameter to assess the average shear rate (γav) in this methodology. Correlations for γav as a function of superficial gas velocity in the riser region (U(GR)) and rheological fluid properties (consistency index, K, and flow index, n) were obtained for each model of pneumatic bioreactor studied.