Extractive fermentation for enhanced production of alkaline phosphatase from Bacillus licheniformis MTCC 1483 using aqueous two-phase systems

Polymer-Based Wound Dressings Loaded with Essential Oil for the Treatment of Wounds: A Review

Wound healing can result in complex problems, and discovering an effective method to improve the healing process is essential. Polymeric biomaterials have structures similar to those identified in the extracellular matrix of the tissue to be regenerated and also avoid chronic inflammation, and immunological reactions. To obtain smart and effective dressings, bioactive agents, such as essential oils, are also used to promote a wide range of biological properties, which can accelerate the healing process. Therefore, we intend to explore advances in the potential for applying hybrid materials in wound healing. For this, fifty scientific articles dated from 2010 to 2023 were investigated using the Web of Science, Scopus, Science Direct, and PubMed databases. The principles of the healing process, use of polymers, type and properties of essential oils and processing techniques, and characteristics of dressings were identified. Thus, the plants Syzygium romanticum or Eugenia caryophyllata, Origanum vulgare, and Cinnamomum zeylanicum present prospects for application in clinical trials due to their proven effects on wound healing and reducing the incidence of inflammatory cells in the site of injury. The antimicrobial effect of essential oils is mainly due to polyphenols and terpenes such as eugenol, cinnamaldehyde, carvacrol, and thymol.

Enhancement of triterpene production via in situ extractive fermentation of Sanghuangporus vaninii YC-1

There have been many studies on the activities and polysaccharide production of Sanghuangporus vaninii. However, few studies have looked at triterpene production from S. vaninii using liquid-state fermentation. A method for enhancing the production of triterpenes by in situ extractive fermentation (ISEF) was studied. Eight solvents were investigated as extractants for triterpene production in the ISEF system. The results showed that using vegetable oil as an extractant significantly increased the yield of total triterpenes and biomass of S. vaninii YC-1, reaching 18.98 ± 0.71 and 44.67 ± 2.21 g/L, respectively. In 5 L fermenter experiments, the added vegetable oil improved the dissolved oxygen condition of the fermentation broth and promoted the growth of S. vaninii YC-1. Furthermore, adding vegetable oil increased the expression of fatty acid synthesis-related genes such as FAD2 and SCD, thereby increasing the synthesis of unsaturated fatty acids in the cell membrane of S. vaninii YC-1. Therefore, the cell membrane permeability of S. vaninii YC-1 increased by 19%. Our results indicated that vegetable oil increased the permeability of S. vaninii YC-1 cell membranes to promote the production of total triterpenes. The use of vegetable oil as an extractant was thus effective in increasing the yield of triterpenes in the ISEF system.

Simultaneous production and sustainable eutectic mixture based purification of narringinase with Bacillus amyloliquefaciens by valorization of tofu wastewater

The current investigation is being executed for sustainable one-pot production and purification of naringinase using natural deep eutectic solvent-based extractive fermentation. Five natural deep eutectic solvents were prepared and their physicochemical properties were determined as a function of temperature. Tofu wastewater was used as a low-cost substrate for naringinase production and simultaneous in-situ purification of the enzyme was accomplished by employing NADES. Optimal conditions of influential factors like concentrations of NADES (74.5% w/w), Na₂SO₄ (15% w/v) and tofu wastewater (1.5% w/w) resulted in an effective yield of naringinase (249.6 U/ml). Scale-up of naringinase production with a 3 l custom made desktop bioreactor was accomplished and effective regeneration of NADES was established. NADES exhibits selectivity during extraction even after the fifth cycle proving it to be tailor-made. The resulting active enzyme was quantified by size exclusion chromatography (736.85 U/mg). Ultrapure enzyme fraction was obtained with anion exchange chromatography yielding maximum purity of (63.2 U/ml) and specific naringinase activity of (3516 U/mg). The in-vitro debittering activity of the resulting ultrapure enzyme fraction was determined with grape juice resulting in naringin and limonin removal of [23.4% (w/w)] and [64.3% (w/w)] respectively.

Comparative bioreactor studies of different process enhancement methods in B. licheniformis for enzyme co-production

Conventional fermentation processes need to be upgraded to produce a wide array of biomolecules to overcome lower product yield. The cost of production of biomolecules using the fermentation method could be reduced by increasing the product yield by various process enhancement methods. In this study, different innovative process enhancement methods were evaluated to increase the co-production of uricase and alkaline protease at the bioreactor level. Ultrasound-assisted fermentation (UAF), Extractive fermentation (ATPS), and Ultrasound-assisted extractive fermentation (UATPS) are the three innovative methods used for process enhancement. Maximum enzyme production was obtained in a combinatorial approach of ultrasound and extractive fermentation, i.e., ultrasound-assisted extractive fermentation where uricase and protease production enhanced by 2.5 fold and 1.9 fold, respectively, as compared to conventional fermentation.

Extractive Fermentation for Recovery of Bacteriocin-Like Inhibitory Substances Derived from Lactococcus lactis Gh1 Using PEG2000/Dextran T500 Aqueous Two-Phase System

This work aimed to optimize the parameters affecting partitioning of a bacteriocin-like inhibitory substances (BLIS) from Lactococcus lactis Gh1 in extractive fermentation using polyethylene glycol (PEG)/dextran aqueous two-phase system (ATPS). This system was developed for the simultaneous cell cultivation and downstream processing of BLIS. Results showed that the molecular weight of PEG, PEG concentration, and dextran T500 affect the partition coefficient (K), purification factor (PF), and yield of BLIS partitioning. ATPS composed of 10% (w/w) PEG2000 and 8% (w/w) dextran T500, provided the greatest conditions for the extractive BLIS production. The K (1.00 ± 0.16), PF (2.92 ± 0.37) and yield (77.24 ± 2.81%) were increased at selected orbital speed (200 rpm) and pH (pH 7). Sustainable growth of the cells in the bioreactor and repeated fermentation up to the eighth extractive batch were observed during the scale up process, ensuring a continuous production and purification of BLIS. Hence, the simplicity and effectiveness of ATPS in the purification of BLIS were proven in this study.

The nutrient-improvement bacteria selected by Agave lechuguilla T. and their role in the rhizosphere community

Agave lechuguilla has one of the widest distributions among other agave species in the Chihuahuan Desert. Their capacity to grow in poorly developed soils and harsh conditions has been related to their association with plant growth-promoting rhizobacteria. In this work, we explored how soil properties and plant growth stage influence the composition of the rhizobacterial communities, their interactions, and the enzymatic activity and abundance of nitrogen-fixing bacteria and organic phosphorus-mineralizing bacteria in two subregions of the Chihuahuan Desert. We found that mature plants of lechuguilla stimulated the activity and abundance of nutrient-improvement rhizobacteria, and these soil samples had a higher content of total organic carbon, ammonium (NH4) and nitrite + nitrate (NO2+NO3). Nutrient availability seems to be an essential driver of the bacterial community's structure since the genera with more connections (hubs) were those with known mechanisms related to the availability of nutrients, such as env. OPS17 (Bacteroidetes), Gemmatimonadaceae uncultured, S0134terrestrial group, BD211terrestrial group (Gemmatimonadetes), Chthoniobacteracea and Candidatus Udaeobacter (Verrucomicrobia). This work shows that the late growth stages of lechuguilla recruit beneficial bacteria that favor its establishment and tolerance to harsh conditions of the arid lands.

Extractive fermentation for process integration of protease production by Aspergillus tamarii Kita UCP1279 and purification by PEG-Citrate Aqueous Two-Phase System

The present study evaluated the influence of the variables polyethylene glycol (PEG) molar mass, pH, PEG concentration and sodium citrate concentration in the integrated production of the protease from Aspergillus tamarii Kita UCP1279 by extractive fermentation, obtaining as a response the partition coefficient (K), activity yield (Y) and concentration factor (CF). The enzyme preferably partitioned to the top phase and obtained in the system formed by variables M_PEG = 400 g mol^-1, C_PEG = 20% (w w^-1), and C_CIT = 20% (w w^-1) and pH 6, in this condition were obtained CF = 1.90 and Y = 79.90%. The protease showed stability at a temperature of 60 °C for 180 min, with optimum temperature 40 °C and pH 8.0. For the ions and inhibitors effects, the protease activity increased when exposed to Fe²⁺, Ca²⁺ and Zn^{2 +} and inhibited by EDTA, being classified as metalloprotease. The kinetic parameters K_m (35.63 mg mL^-1) and V_max (1.205 mg mL^-1min^-1) were also estimated. Thus, the protease showed desirable characteristics that enable future industrial applications, especially, for beer industry.

Dynamic cross correlation analysis of Thermus thermophilus alkaline phosphatase and determinants of thermostability

BACKGROUND

Understanding the determinants of protein thermostability is very important both from the theoretical and applied perspective. One emerging view in thermostable enzymes seems to indicate that a salt bridge/charged residue network plays a fundamental role in their thermostability.

METHODS

The structure of alkaline phosphatase (AP) from Thermus thermophilus HB8 was solved by X-ray crystallography at 2.1 Å resolution. The obtained structure was further analyzed by molecular dynamics studies at different temperatures (303 K, 333 K and 363 K) and compared to homologous proteins from the cold-adapted organisms Shewanella sp. and Vibrio strain G15-21. To analyze differences in measures of dynamic variation, several data reduction techniques like principal component analysis (PCA), residue interaction network (RIN) analysis and rotamer analysis were used. Using hierarchical clustering, the obtained results were combined to determine residues showing high degree dynamical variations due to temperature jumps. Furthermore, dynamic cross correlation (DCC) analysis was carried out to characterize networks of charged residues.

RESULTS

Top clustered residues showed a higher propensity for thermostabilizing mutations, indicating evolutionary pressure acting on thermophilic organisms. The description of rotamer distributions by Gini coefficients and Kullback-Leibler (KL) divergence both revealed significant correlations with temperature. DCC analysis revealed a significant trend to de-correlation of the movement of charged residues at higher temperatures.

SIGNIFICANCE

The de-correlation of charged residues detected in Thermus thermophilus AP, highlights the importance of dynamic electrostatic network interactions for the thermostability of this enzyme.

In situ product recovery techniques aiming to obtain biotechnological products: A glance to current knowledge

Biotechnology and bioengineering techniques have been widely used in the production of biofuels, chemicals, pharmaceuticals, and food additives, being considered a "green" form of production because they use renewable and nonpolluting energy sources. On the other hand, in the traditional processes of production, the target product obtained by biotechnological routes must undergo several stages of purification, which makes these processes more expensive. In the past few years, some works have focused on processes that integrate fermentation to the recovery and purification steps necessary to obtain the final product required. This type of process is called in situ product recovery or extractive fermentation. However, there are some differences in the concepts of the techniques used in these bioprocesses. In this way, this review sought to compile relevant content on considerations and procedures that are being used in this field, such as evaporation, liquid-liquid extraction, permeation, and adsorption techniques. Also, the objective of this review was to approach the different configurations in the recent literature of the processes employed and the main bioproducts obtained, which can be used in the food, pharmaceutical, chemical, and/or fuel additives industry. We intended to elucidate concepts of these techniques, considered very recent, but which emerge as a promising alternative for the integration of bioprocesses.

One-pot simultaneous production and sustainable purification of fibrinolytic protease from Bacillus cereus using natural deep eutectic solvents

The present study report for the first time on the one-pot production and purification of fibrinolytic protease from Bacillus cereus by extractive fermentation using natural deep eutectic solvents (NADES). Cheese whey was chosen as a sustainable low-cost production alternative yielding a significantly high amount of protease (185.7 U/mg). Five natural deep eutectic solvents with menthol as hydrogen bond donor and sugar molecules as corresponding hydrogen bond acceptors were synthesized and their association was confirmed with H1 NMR. Thermophysical investigation of the synthetic NADES was accomplished as a function of temperature to define their extraction ability. Response surface methodology based optimization of concentration of NADES (77.5% w/w), Na2SO4 (14% w/v) and cheese whey (1% w/w) were accomplished for extractive fermentation. Further, preparative purification using size exclusion chromatography was used to quantify the amount of enzyme obtained in the extraction phase (190 U/ml). On subsequent purification with an anion exchange column, the maximum purity fold (21.2) with enzyme activity (2,607.8 U/ml) was attained. The optimal pH (8.0), temperature (50 °C) were determined and the in-vitro fibrinolytic activity has been confirmed using a fibrin plate assay.

Spirulina platensis based biorefinery for the production of value-added products for food and pharmaceutical applications

In this present study, microalgal phycobiliproteins were isolated and purified via potential biphasic processing technique for pharmaceutical as well as food applications. The algal pre-treatment techniques were studied to enhance the yield of microalgal phycobiliproteins from the biomass. The proposed methods were optimised to obtain the best recovery yield of phycobiliproteins that can be isolated from the biomass. The phycobiliproteins were further purified using liquid biphasic system. The results showed that microalgal phycobiliproteins of high purity and yield was achieved using sonication treatment (20% power, 50% duty cycle and 7 min of irradiation time) with the biphasic system, where the purification fold of 6.17 and recovery yield of 94.89% was achieved. This work will provide insights towards the effective downstream processing of biomolecules from microalgae.

Application of thermo-separating aqueous two-phase system in extractive bioconversion of polyhydroxyalkanoates by Cupriavidus necator H16

Polyhydroxyalkanoates (PHAs), a family of biodegradable and renewable biopolymers show a huge potential as an alternative to conventional plastics. Extractive bioconversion (in situ product recovery) is a technique that integrates upstream fermentation and downstream purification. In this study, extractive bioconversion of PHAs from Cupriavidus necator H16 was performed via a thermo-separating aqueous two-phase system to reduce the cost and environmental impacts of PHAs production. Key operating parameters, such as polymer concentration, temperature, and pH, were optimized. The strategy achieved a yield and PF of 97.6% and 1.36-fold, respectively at 5% EOPO 3900 concentration, 30 °C fermentation temperature and pH 6. The PHAs production process was also successfully scaled up in a 2 L bioreactor. To the best of our knowledge, this is the first report on extractive fermentation of PHAs from Cupriavidus necator utilizing a thermo-separation system to achieve a better productivity and purity of the target product.

In situ removal of consensus dengue virus envelope protein domain III fused to hydrophobin in Pichia pastoris cultures

This work describes a novel strategy for the integrated expression and purification of recombinant proteins in Pichia pastoris cultures. Hydrophobins can be used as fusion tags, proteins fused to them alter their hydrophobicity and can be purified by aqueous two-phase systems (ATPS) based on non-ionic surfactants. Here, the consensus dengue virus envelope protein domain III fused to hydrophobin I of Trichoderma reesei was expressed in Pichia pastoris cultures and an in situ product removal by an ATPS using a non-ionic detergent, (Triton X-114) was performed. The protein was produced and purified directly from the yeast culture supernatant both efficiently and with no loss. The purified protein was properly immobilized by adsorption in solid phase and recognized by anti-dengue antibodies, showing its potential for the development of an indirect immunoassay for dengue virus.

Aqueous two-phase system (ATPS): an overview and advances in its applications

Aqueous two-phase system (ATPS) is a liquid-liquid fractionation technique and has gained an interest because of great potential for the extraction, separation, purification and enrichment of proteins, membranes, viruses, enzymes, nucleic acids and other biomolecules both in industry and academia. Although, the partition behavior involved in the method is complex and difficult to predict. Current research shows that it has also been successfully used in the detection of veterinary drug residues in food, separation of precious metals, sewage treatment and a variety of other purposes. The ATPS is able to give high recovery yield and is easily to scale up. It is also very economic and environment friendly method. The aim of this review is to overview the basics of ATPS, optimization and its applications.

Thermoseparating aqueous two-phase systems: Recent trends and mechanisms

Having the benefits of being environmentally friendly, providing a mild environment for bioseparation, and scalability, aqueous two-phase systems (ATPSs) have increasingly caught the attention of industry and researchers for their application in the isolation and recovery of bioproducts. The limitations of conventional ATPSs give rise to the development of temperature-induced ATPSs that have distinctive thermoseparating properties and easy recyclability. This review starts with a brief introduction to thermoseparating ATPSs, including its history, unique characteristics and advantages, and lastly, key factors that influence partitioning. The underlying mechanism of temperature-induced ATPSs is covered together with a summary of recent applications. Thermoseparating ATPSs have been proven as a solution to the demand for economically favorable and environmentally friendly industrial-scale bioextraction and purification techniques.

Aqueous two phase partitioning of fish proteins: partitioning studies and ATPS evaluation

A suitable Aqueous Two Phase System (ATPS) has been identified for the partitioning of crude fish proteins from fish processing industrial effluent. A detailed study has been performed to analyze the influence of various parameters on protein partitioning such as molecular weight of PEG, effect of different salts (MgSO4, K2HPO4, Na3C6H5O7, Na2SO4, (NH4) 2PO4, K3C6H5O7) and their concentrations, pH, temperature, Tie Line Length (TLL), effluent loading and volume ratio. PEG 2000 - sodium sulphate ATPS was found to be a most favourable system among the selected ATPS for higher partition coefficient of proteins. The binodal curve and equilibrium characteristics of PEG 2000 - sodium sulphate were established and fitted to empirical equations. The equilibrium compositions (tie line) were correlated using Othmer-Tobias and Bancroft equations.

Potential application of aqueous two-phase systems and three-phase partitioning for the recovery of superoxide dismutase from a clarified homogenate of Kluyveromyces marxianus

Superoxide dismutase (SOD; EC 1.15.1.1) is an antioxidant enzyme that represents the primary cellular defense against superoxide radicals and has interesting applications in the medical and cosmetic industries. In the present work, the partition behavior of SOD in aqueous two-phase systems (ATPS) (using a standard solution and a complex extract from Kluyveromyces marxianus as sample) was characterized on different types of ATPS (polymer-polymer, polymer-salt, alcohol-salt, and ionic liquid (IL)-salt). The systems composed of PEG 3350-potassium phosphate, 45% TLL, 0.5 M NaCl (315 U/mg, 87% recovery, and 15.1-fold purification) and t-butanol-20% ammonium sulfate (205.8 U/mg, 80% recovery and 9.8-fold purification), coupled with a subsequent 100 kDa ultrafiltration stage, allowed the design of a prototype process for the recovery and partial purification of the product of interest. The findings reported herein demonstrate the potential of PEG-salt ATPS for the potential recovery of SOD.

Extractive fermentation for improved production and recovery of lipase derived from Burkholderia cepacia using a thermoseparating polymer in aqueous two-phase systems

An extractive fermentation technique was developed using a thermoseparating reagent to form a two-phase system for simultaneous cell cultivation and downstream processing of extracellular Burkholderia cepacia lipase. A 10% (w/w) solution of ethylene oxide-propylene oxide (EOPO) with a molecular mass of 3900 g/mol and pH 8.5, a 200 rpm speed, and 30 °C were selected as the optimal conditions for lipase production (55 U/ml). Repetitive batch fermentation was performed by continuous replacement of the top phase every 24h, which resulted in an average cell growth mass of 4.7 g/L for 10 extractive batches over 240 h. In scaling-up the process, a bench-scale bioreactor was tested under the conditions that had been optimized in flasks. The production rate and recovery yield were higher in the bioreactor compared to fermentation performed in flasks.

Partitioning studies of L-glutaminase production by Bacillus cereus MTCC 1305 in different PEG-salt/dextran

Partitioning studies of L-glutaminase production by Bacillus cereus MTCC 1305 was carried out in different PEG-salt/PEG-dextran system. The partitioning value of L-glutaminase increased with increasing molecular weight of PEG from 2000-4000 kDa and decreased with higher molecular weight of 6000 kDa. Phase system of PEG 4000 (8.5%)/dextran T500 (9.5%) was selected for the extractive fermentative production of L-glutaminase on the basis maximum partition coefficient (1.31). The production of L-glutaminase was found higher in top phase of ATPS (2.09 U/ml) than control media (1.42 U/ml). Overall production of L-glutaminase (1.83 U/ml) was found lower than top phase (2.09 U/ml) in ATPS system. The growth profile with short lag phase and higher cell concentration was obtained for ATPS. The partition coefficient of L-glutaminase increased with increase of system pH and temperature and optimum production was obtained at pH 7.5 and temperature 30 °C in top phase of PEG 4000/dextran T500 system.