•The review deals with the current state the of art of lipases from Pseudomonas.•The production and properties of lipases from Pseudomonas are discussed.•Many strategies of immobilization of lipases ...from Pseudomonas are presented.•Lipases from Pseudomonas potential in biotechnological applications is outlined.
Lipases from Pseudomonas are extracellular enzymes that play an important role in biotechnological and industrial processes, due to their application in biofuels, food and pharmaceutical industries. Therefore, this paper provides an overview about the main aspects of the lipases from Pseudomonas, regarding their catalytic characterization, production, immobilization and application in many reactions of high industrial interest. The catalytic characterization and production of the lipase will be discussed, including the main lipase properties available in the literature and the influence of media composion, making possible the optimization of lipase production. Based on the main features of the lipases from Pseudomonas, this review also explores the recent developments on strategies of immobilization in order to enable recovery operations of the biocatalyst. The application of lipases to production of many high added-value products through esterifications, hydrolysis reactions and resolution of racemic compounds was also explored. The high yield and enantioselectivity of their reactions, regarding the resolution of racemic mixtures, shows that the lipases from Pseudomonas are efficient biocatalysts for biotechnological processes.
•Higher efficient saccharification achieved with pretreatment at 35°C, 4.3% v/v H2O2, 5% w/v CAB for 6h.•Cellulose content increased and lignin content decreased after PHA pretreatment.•Cellulose ...hydrolysis yields were enhanced.•Higher lignin removal gave better digestibility and yields.•Pretreated CAB presented molecule and surface structure changes.
The alkaline hydrogen peroxide (AHP) pretreatment of cashew apple bagasse (CAB) was evaluated based on the conversion of the resultant cellulose into glucose. The effects of the concentration of hydrogen peroxide at pH 11.5, the biomass loading and the pretreatment duration performed at 35°C and 250rpm were evaluated after the subsequent enzymatic saccharification of the pretreated biomass using a commercial cellulase enzyme. The CAB used in this study contained 20.56±2.19% cellulose, 10.17±0.89% hemicellulose and 35.26±0.90% lignin. The pretreatment resulted in a reduced lignin content in the residual solids. Increasing the H2O2 concentration (0–4.3% v/v) resulted in a higher rate of enzymatic hydrolysis. Lower biomass loadings gave higher glucose yields. In addition, no measurable furfural and hydroxymethyl furfural were produced in the liquid fraction during the pretreatment. The results show that alkaline hydrogen peroxide is effective for the pretreatment of CAB.
•B. subtilis ICA56 isolated from a Brazilian mangrove produced an effective tensoative.•The biosurfactants were stable under extreme conditions (pH, temperature and salinity).•It was capable to ...remove hydrocarbons and heavy metals from contaminated systems.•The biosurfactant presented low toxicity.•Biosurfactant concentration was 1.29gL−1 when glycerol was used as substrate.
This work aimed to study the production of a biosurfactant by a new strain of Bacillus subtilis ICA56 isolated from a Brazilian mangrove and to evaluate its functional properties and applicability for bioremediation. The use of agro-industrial wastes (glycerol, sunflower oil, cheese whey and cashew apple juice) as alternative substrates for biosurfactant production was tested as this may lead to a reduction in the cost of the bioprocess. Glycerol was the best carbon source yielding 1290mgL−1 of crude biosurfactant. The critical micellar concentration of the crude biosurfactant produced by ICA56 was 25mgL−1 and, at this concentration, it was able to reduce the surface tension of the water from 72 to 30mNm−1 and to reduce the interfacial tension on a water/gasoline system from 15 to 3mNm−1. Furthermore, the crude biosurfactant retained its tensoative properties in a broad range of pH, temperature and salinity and it was not toxic to Artemia salina. In this work, model experiments were conducted to simulate the removal of hydrocarbons and heavy metals from contaminated environmental systems in the laboratory by the crude biosurfactant produced by ICA56. Results showed that it was very efficient, highlighting its potential for bioremediation.
The adsorption of pharmaceutical substances using carbonaceous materials, such as activated carbon (AC), biochar (BC) and hydrochar (HC), has received substantial attention by researchers working on ...water treatment, due to the simplicity, low-cost and high performance of this process. In order to widen the potentiality of these carbonaceous materials and to overcome some of their limitations, particularly the inefficient separation of powdered formulations from treated water, the incorporation of magnetic nanoparticles has been explored. The recovery of magnetic carbon materials (MCM) from the treated water can be attained by applying an external magnetic field, avoiding inefficient and costly filtration and centrifugation processes, typically applied in the case of non-magnetic carbonaceous adsorbents. In the last ten years, some work has been devoted to the preparation of MCM specifically from AC (MCACM), biochar (MCBCM) and hydrochar (MCHCM). This review aims to present the different aspects of using MCM in water treatment, namely in the removal of pharmaceutical compounds. The synthesis routes used to produce MCM, their physical, morphologic and chemical features, and their application in the removal of these micro-organic contaminants from water will be assessed. The advantages and disadvantages of using MCM in water treatment, and their comparative performance with the carbonaceous non-magnetic precursors will be also discussed in this review.
Display omitted
•Carbon adsorbents have been used as precursors of magnetic carbon materials (MCM).•Synthesis methods to produce MCM are presented.•Adsorption studies of pharmaceuticals by means of MCM are discussed.•Optimal relation between magnetic properties and binding efficacy is a key challenge.•Economic and technical viability of MCM application at full scale must be assessed.
Display omitted
•A straightforward chemoenzymatic synthesis of (S)-Pindolol has been developed.•The key step involved kinetic lipase-mediated resolution of a haloydrin acetate via hydrolytic ...process.•P. fluorescens was a robust biocatalyst and afforded the halohydrin acetate as chiral intermediate with 97% ee.•The use of THF as co-solvent was essential for a high enantioselectivity kinetic resolution process (E>200).
A straightforward chemoenzymatic synthesis of (S)-Pindolol has been developed. The key step involved the enzymatic kinetic resolution of rac-2-acetoxy-1-(1H-indol-4-yloxy)-3-chloropropane with lipase from Pseudomonas fluorescens via hydrolytic process to obtain enantiomerically enriched halohydrin (2S)-1-(1H-indol-4-yloxy)-3-chloro-2-propanol (96% ee) and (2R)-2-acetoxy-1-(1H-indol-4-yloxy)-3-chloropropane (97% ee). The latter was subjected to a hydrolysis reaction catalyzed by Candida rugosa leading to (2R)-1-(1H-indol-4-yloxy)-3-chloro-2-propanol (97% ee), followed by a reaction with isopropylamine, producing (S)-Pindolol (97% ee) in quantitative yield.
Immobilization is a powerful strategy for improving enzyme usability and stability in various technologies that employ biocatalysis. However, the interactions leading to stabilization or ...destabilization remain poorly understood, and a support that may stabilize one enzyme may destabilize another. Employing chemically heterogeneous and complex random copolymer brushes as supports, we demonstrate a rational approach toward estimating the chemical composition of an optimally stabilizing enzyme immobilization support by computational analysis of enzyme surface hydrophobicity. This approach was tested by immobilizing a range of enzymes with diverse functions and hydrophobicity on tunable statistical random copolymer brush supports composed of poly(ethylene glycol) methacrylate (PEGMA) and sulfobetaine methacrylate (SBMA). Remarkably, we observed greatly improved enzyme performance as a function of brush composition with enhancements in the retention of catalytic activity at temperatures as high as 90 °C. Additionally, we observed an increase in activity at the optimal temperature by as much as 20-fold relative to the activity at the optimal temperature of the unimmobilized form of the enzyme. Most significantly, our results showed that the optimal composition of the brush support correlated with the overall hydrophobicity of the enzyme surface (ΔG solv,total/area), which was determined from computational analysis. This correlation provides a framework for the choice of polymer brush supports based on enzyme structure and stabilizing enzymes using complex synthetic materials.
NiZnFe2O4 superparamagnetic nanoparticles were coated with silica by impregnation with tetraethoxysilane (TEOS) and further activated with divinylsulfone (DVS) and p-benzoquinone (BQ) for covalent ...immobilization lipase from Pseudomonas fluorescens (PFL), producing the biocatalysts TEOS-NANO-DVS-PFL and TEOS-NANO-BQ-PFL. The optimal conditions for enzyme immobilization were found to be pH 7 and 0.1 M of both activating reagents. PFL was also immobilized on TEOS nanoparticles without any activation as a reference (TEOS-NANO-PFL). Results indicated that TEOS could be released from the nanoparticles at alkaline pH value. Optimal TEOS-NANO-PFL exhibited a recovered activity of 55% and a t1/2(60°C) of just over 150 min; while TEOS-NANO-DVS-PFL showed 82% of activity recovered and t1/2(60°C) of 225 min; being the TEOS-NANO-BQ-PFL the biocatalyst offering the best results (89% of recovered activity and a half-life over 1440 min), the maximum enzyme load was ≈300 U/g.
•NiZnFe2O4 superparamagnetic nanoparticles were coated TEOS and further activated with DVS or BQ.•The support activation has been optimized, the release of TEOS at alkaline pH values become a problem.•PFL has been immobilized on NANO-TEOS, NANO-TEOS-DVS and NANO-TEOS BQ.•Optimal biocatalyst has been obtained by immobilizing PFL on NANO-TEOS BQ at pH 7 for 24 h.•Under stress inactivations, TEOS-NANO-BQ-PFL half live was 24 h while that of TEOS-NANO-PFL was 2.5 h.
•SSF strategies for ethanol production from CAB was investiagted.•A pre-saccharification step was conducted prior to SSF.•Fed-batch SSF process enabled the increase in final ethanol concentration ...from CAB.
Simultaneous saccharification and fermentation (SSF) is a promising process for the bioconversion of lignocellulosic biomass. Furthermore, an efficient approach to reduce the capital costs for the production of bio-based products is the use of high glucan loading. Therefore, in this study, a comparison of SSF strategies were investigated aiming to enhance ethanol production from acidic-alkaline pretreated cashew apple bagasse (CAB-OH) by Kluyveromyces marxianus ATCC36907 at high glucan loading. An ethanol concentration of 58g/L was achieved with 15% CAB-OH using batch SSF, resulting in an 81.2% overall ethanol yield. Prehydrolysis of 12h, prior to SSF, did not significantly increase the overall ethanol yield. Fed-batch SSF, using high loadings of solids, was also investigated. Ethanol concentrations of up to 67g/L could be produced from CAB-OH (20% w/v) by adding fresh substrate every 4h during the first 48h of SSF (10% initial and 2.5% of feeding), achieving an overall ethanol yield of 81%. In the fed-batch mode, the amount of enzyme was lower than used in batch and this process allowed higher ethanol concentrations and similar yield. No major differences in fed-batch performance, considering ethanol concentration and yield, were observed for the different feeding amounts, around 68g/L and 80.7%, respectively.
Ethanol production from acidic-alkaline pretreated cashew apple bagasse (CAB-OH) was investigated using separated hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation ...(SSF) processes. First, a screening of
Kluyveromyces
strains was conducted by SHF and a maximum ethanol concentration of 24.1 g L
−1
was obtained using
Kluyveromyces marxianus
ATCC36907, which presented similar profiles when compared to results obtained by a
Saccharomyces
strain. The effect of temperature on ethanol production conducted by SHF using
K. marxianus
ATCC36907 was investigated, and the maximum ethanol yield (Y
E/G
) was obtained at 40 °C (0.46 g g
−1
) using a synthetic medium. In the SHF using CAB-OH hydrolysate, the maximum ethanol concentration obtained was 24.9 g L
−1
, 5.92 g L
−1
h
−1
of productivity, and ethanol yield of 0.43 g g
−1
at 40 °C. Afterwards,
K. marxianus
ATCC36907 was used in the bioconversion of CAB-OH by SSF, and an ethanol concentration of 41.41 ± 0.2 g L
−1
was obtained using 10 % CAB-OH at 40 °C, 150 rpm and 24 h, resulting in a Yʹ
E/G
of 0.50 g
E
g
G
−1
and an efficiency of 98.4 %, in the process conducted with cellobiase supplementation. SHF and SSF processes using CAB-OH and
K. marxianus
ATCC36907 can be used to ethanol production, but the SSF process required only one step to achieve the same production.
PDF
