Optimum Substrate Concentration Research Articles

Pectinase production by Aspergillus niger using banana (Musa balbisiana) peel as substrate and its effect on clarification of banana juice.

Optimization of substrate concentration, time of incubation and temperature for crude pectinase production from A. niger was carried out using Bhimkol banana (Musa balbisiana) peel as substrate. The crude pectinase produced was partially purified using ethanol and effectiveness of crude and partially purified pectinase was studied for banana juice clarification. The optimum substrate concentration, incubation time and temperature of incubation were 8.07%, 65.82h and 32.37°C respectively, and the polygalacturonase (PG) activity achieved was 6.6 U/ml for crude pectinase. The partially purified enzyme showed more than 3 times of polygalacturonase activity as compared to the crude enzyme. The SDS-PAGE profile showed that the molecular weight of proteins present in the different pectinases varied from 34 to 42kDa. The study further revealed that highest clarification was achieved when raw banana juice was incubated for 60min with 2% concentration of partially purified pectinase and the absorbance obtained was 0.10.

Effect of system optimizing conditions on biohydrogen production from herbal wastewater by slaughterhouse sludge

The study evaluates the biohydrogen production from herbal wastewater as the substrate by the enriched mixed slaughterhouse sludge as the seed source. In the following experiments, batch-fermentations are carried out with the optimum substrate concentrations, fermentation pH and fermentation temperature to observe the effects of H2 production, hydrogen yield and other fermentation end products at different conditions. The hydrogen production is increased as substrate concentration increased up to 8 g COD/L WW, but drastically decreased at 10 g COD/L WW. When the pH of fermentation is controlled to 6.5, a maximum amount of hydrogen yield could be obtained. The hydrogen production is maximum at 50 °C (930 ± 30 mL/L WW) compared to 30 °C (436 ± 16 mL/L WW). Acid-forming pathway with butyric acid as a major metabolite dominated the metabolic flow during the hydrogen production. The experimental results indicated that effective hydrogen production from the herbal wastewater could be obtained by thermophilic acidogenesis at proper operational conditions.

Efficient glycosylation of puerarin by an organic solvent-tolerant strain of Lysinibacillus fusiformis

A bacterial strain able to glycosylate the plant natural product puerarin was isolated from local soil in Nanjing, China. It was identified as Lysinibacillus fusiformis, and deposited in China General Microbiological Culture Collection (CGMCC) under accession number 4913. Incubation of this strain with puerarin led to efficient production (91.6% conversation rate) of puerarin-7-O-fructoside, a derivative that possesses improved water solubility and antioxidant activity. A minor product puerarin-7-O-isomaltoside was also produced in small amounts, with a conversion rate of less than 1% after 48-h reaction. Both products were characterized based on the spectral data. Among the four tested sugars, sucrose (92.6% conversion rate of puerarin) is the best glycosyl donor for L. fusiformis CGMCC 4913, followed by maltose (39.8% conversion rate of puerarin), while glucose and fructose are not appropriate donors for this biotransformation process. L. fusiformis CGMCC 4913 can survive in the presence of 10% (v/v) organic solvents such as methanol, ethanol, toluene, cyclohexane, and dimethyl sulfoxide. The biotransformation efficiency of puerarin was increased 2-fold in the presence of 10% ethanol at 12h compared to the transformation solution without ethanol. The optimum pH and substrate concentration are 8.0 and 4g/L, respectively. Under the optimal conditions, the final conversion rate of puerarin reached 97.6±2.3% at 48h in the presence of 10% ethanol. Therefore, L. fusiformis CGMCC 4913 represents a new and efficient biocatalyst for the biotransformation of puerarin.

Enhanced polyhydroxyalkanoate production from organic wastes via process control

This work explores the use of a model-based control scheme to enhance the productivity of polyhroxyalkanoate (PHA) production in a mixed culture two-stage system fed with synthetic wastewater. The controller supplies pulses of substrate while regulating the dissolved oxygen (DO) concentration and uses the data to fit a dynamic mathematical model, which in turn is used to predict the time until the next pulse addition. Experiments in a bench scale system first determined the optimal DO set-point and initial substrate concentration. Then the proposed feedback control strategy was compared with a simpler empiric algorithm. The results show that a substrate conversion rate of 1.370±0.598mgPHA/mgCOD/d was achieved. The proposed strategy can also indicate when to stop the accumulation of PHA upon saturation, which occurred with a PHA content of 71.0±7.2wt.%.

Performance of β-Glucosidase produced by Ganoderma lucidum using Waste Substrate as Carbon Source

Oil palm empty fruit bunch (OPEFB) was used for the production of β-glucosidase by Ganoderma lucidum in submerged fermentation. The activity of β-glucosidase had shown an improvement by going from pH 4 to 6 and declined towards alkaline pH. The highest activity (47.75 U/mL) was obtained at pH 6 with 2.0 mm size of substrate’s particle. The smaller the particles size, the higher surface area of substrate which provides more space for hyphae to colonize. Optimum substrate concentration was obtained at 6.0 g/L (43.99 U/mL). The highest β-glucosidase activity occurred at 27 ºC (53.37 U/mL). The nutrient content in composted OPEFB provides a relevant reason that should be considered in the performance of high activity β-glucosidase enzyme. Therefore, the results of this study can be used to produce high activity β-glucosidase using cheap and economical substrate (compost OPEFB).

Bioethanol fermentation of Jerusalem artichoke using mixed culture ofSaccharomyces cerevisiaeandKluyveromyces marxianus

Effects of mixed cultures of Saccharomyces cerevisiae Levuline FB — higher ethanol tolerance — and different Kluyveromyces strains — higher inulinase activity — on the production of ethanol from Jerusalem artichoke extract were investigated. Among the investigated strains, combination of S. cerevisiae and K. marxianus strain Y00959 with simultaneous saccharification and fermentation gave the best efficiency (76%) of bioconversion. The optimal ratio of mixed cultures was determined to be 1:1 of K. marxianus and S. cerevisiae. Central composite design (CCD) was adapted to find the optimum initial substrate concentration and inoculum size for the maximal production of ethanol from Jerusalem artichoke juice. The optimum fermentation conditions were found to be 24% (m/w) substrate concentration and 45 OD600nm ml/100 ml inoculum size of mixed culture. Use of these conditions, about 10.67% (v/v) was produced at 148 h of alcoholic fermentation given. Results of this work provide benefits of mixed culture on produ...

Microbacterium oxydans, a novel alginate- and laminarin-degrading bacterium for the reutilization of brown-seaweed waste

There is a growing demand for the efficient treatment of seaweed waste. We identified six bacterial strains from the marine environment for the reutilization of brown-seaweed waste, and the most potentially useful strain, Microbacterium oxydans, was chosen and further investigated. Plate assays indicated that this bacterial isolate possessed both alginate lyase and laminarinase activities. The optimal inoculum size, pH, temperature and substrate concentration for the degradation of brown-seaweed polysaccharides by the isolate were as follows: 20% (v v−1), pH 6.0, 37 °C, and 5 g L−1 for alginate and 20% (v v−1), pH 6.0, 30 °C, and 10 g L−1 for laminarin, respectively. During 6 d in culture under the optimal conditions, the isolate produced 0.17 g L−1 of reducing sugars from alginate with 11.0 U mL−1 of maximal alginate lyase activity, and 5.11 and 2.88 g L−1 of reducing sugars and glucose from laminarin, respectively. In particular, a fair amount of laminarin was degraded to glucose (28.8%) due to the isolate's exolytic laminarinase activity. As a result, the reutilization of brown-seaweed waste by this isolate appears to be possible for the production of reducing sugars as a valuable resource. This is the first study to directly demonstrate the ability of M. oxydans to degrade both alginate and laminarin.

Continuous production of β-cyclodextrin from starch by highly stable cyclodextrin glycosyltransferase immobilized on chitosan

Cyclodextrin glycosyltransferase (CGTase) from Thermoanaerobacter sp. was covalently immobilized on glutaraldehyde-activated chitosan spheres and used in a packed bed reactor to investigate the continuous production of β-cyclodextrin (β-CD). The optimum temperatures were 75°C and 85°C at pH 6.0, respectively for free and immobilized CGTase, and the optimum pH (5.0) was the same for both at 60°C. In the reactor, the effects of flow rate and substrate concentration in the β-CD production were evaluated. The optimum substrate concentration was 4% (w/v), maximizing the β-CD production (1.32g/L) in a flow rate of 3mL/min. In addition, the biocatalyst had good operational stability at 60°C, maintaining 61% of its initial activity after 100 cycles of batch and 100% after 100h of continuous use. These results suggest the possibility of using this immobilized biocatalyst in continuous production of CDs.

Some applications of α-amylase produced by Bacillus subtilis NCTC-10400 and Bacillus cereus ATCC 14579 under solid state fermentation

This paper describes the production of α-amylase by Bacillus subtilis NCTC-10400 andBacillus cereus ATCC 14579 using wheat bran as a substrate under Solid State Fermentation (SSF). Supplementation of carbon and nitrogen sources resulted in marginal increase in α-amylase production. Highest production was observed with fructose and ammonium chloride (180.8 U/g) for B. subtilis and with glucose and yeast extract (152.80 U /g) for B. cereus. Addition of Tween 80 to the medium is effective in enzyme production by B. subtilis (230.00 U/g) and B. cereus (180.92 U/g) in SSF. The various environmental process parameters were optimized, namely, moisture level, inoculum concentration, pH, incubation temperature and fermentation period showed 1:2, 10%, pH 7, 35°C and 72 h, respectively for both strains. The obtained crude amylases have optimum substrate concentration at 7% (w/w), optimum pH of 7.0, optimum temperature of 50°C and optimum enzymatic reaction time of 30 min. The potential of the amylase for degrading the starches of wheat bran wastes into glucose was carried out, and then the process was continued by fermentation to produce bioethanol with the result of 2.2 and 1.6% (v/v) by B. subtilis and B. cereus, respectively. In industrial settings, both the inactivation and removal of biofilms are of huge concern. Alpha amylase compounds from both strains were evaluated for their ability to inhibit biofilm formation of several pathogenic bacteria. Key words: Solid state fermentation (SSF), Bacillus subtilis, Bacillus cereus, wheat bran, α-amylase, bioethanol fermentation, biofilm control.

Spirosoma xylofaga sp. nov., an oligotrophic pleomorphic bacterium from a myco-bacterial community of freshwater ecosystems

A novel aerobic bacterial strain Z-0088 was assigned to the genus Spirosoma on the basis of 16S rRNA analysis; it was isolated from a bacterial community of moderately acidic (pH 5.0) dystrophic, slightly humified water formed by xylotrophic fungi grown on decaying spruce wood. The cells are nonmotile, gramnegative, straight or curved rods, 0.5–1.5 × 1.0–6.0 μm; they may also be toroidal. The cells are usually single but can form spiral filaments containing from 4 to 13 coils; their reproduction is by division. Strain Z-0088 is an organoheterotroph utilizing xylan, inulin, xylose, sucrose, and N-acetylglucosamine as organic growth substrates. The bacterium is oligotrophic (the optimum substrate concentration is 0.5 g/L). It is characterized by high sensitivity to NaCl concentration; growth was completely suppressed at 1% NaCl. The strain grows in a pH range of 3.8–7.5 with the optimum at pH 5.5–6.5. The temperature range for growth was 13–35°C with the optimum at 28°C. The DNA G+C base content was 50.2 mol %. The ecophysiological features of strain Z-0088, such as oligotrophic, mesophilic, moderate acidophilic properties, and sensitivity to NaCl, support its designation as a representative of ombrophilic dissipotrophs. The strain is assigned to a novel species Spirosoma xylofaga sp. nov.

ACE-inhibitory peptides production from defatted wheat germ protein by continuous coupling of enzymatic hydrolysis and membrane separation: Modeling and experimental studies

To increase the yield and activity of angiotensin converting enzyme (ACE) inhibitory peptides from defatted wheat germ protein (DWGP), an efficient method of continuous coupling of enzymatic hydrolysis and membrane separation (CEH-MS) and its kinetics were systematically studied. The results showed the steady state theory fitted the continuous CEH-MS kinetics study well and the kinetic model was successfully established with Km of 8.163g/L and Vmax of 0.790g/Lmin. Both the degree of hydrolysis and the conversion rate of protein were significantly affected by substrate concentration. By the kinetic model prediction, the optimum substrate concentration was 10.65g/L. Considering the safe pressures of flushing and backflushing ultrafiltration, the maximum runtime of the continuous CEH-MS reactor was 300min. Under the optimum conditions of substrate concentration of 10.65g/L, Alcalase quantity of 0.51g, temperature of 50°C, pH of 9.0, permeation flux of 0.011L/min, effective volume of 0.4 L, and runtime of 300min, the continuous CEH-MS method showed high conversion rate of protein (65.21%), yield of peptides (34.10g/g), and IC50 of peptides (0.452g/L). The conversion rate of protein and yield of peptides were significantly increased by 63.4% and 7.1 times, and the IC50 of peptides was significantly reduced by 13.6% compared with the traditional EH and offline MS one. Therefore, the continuous CEH-MS reactor is beneficial to the efficient production of ACE-inhibitory peptides from DWGP.

Immobilization of α-amylase and amyloglucosidase onto ion-exchange resin beads and hydrolysis of natural starch at high concentration

α-Amylase was immobilized on Dowex MAC-3 with 88 % yield and amyloglucosidase on Amberlite IRA-400 ion-exchange resin beads with 54 % yield by adsorption process. Immobilized enzymes were characterized to measure the kinetic parameters and optimal operational parameters. Optimum substrate concentration and temperature were higher for immobilized enzymes. The thermal stability of the enzymes enhanced after the immobilization. Immobilized enzymes were used in the hydrolysis of the natural starch at high concentration (35 % w/v). The time required for liquefaction of starch to 10 dextrose equivalent (DE) and saccharification of liquefied starch to 96 DE increased. Immobilized enzymes showed the potential for use in starch hydrolysis as done in industry.

Optimisation of the Enzymatic Hydrolysis of Blood Cells with a Neutral Protease

For utilizing the blood cells (BCs) effectively, enzymatic hydrolysis was applied to produce the enzymatically hydrolyzed blood cells (EHBCs) by using a neutral protease as a catalyst. The results of the single-factor experiments showed optimal substrate concentration, enzyme to substrate ratio (E/S), pH, temperature, and incubation period were 1.00%, 0.10, 7.00, 50.00°C, and 12.00 h, respectively. The optimized hydrolysis conditions from response surface methodology (RSM) were pH 6.50, E/S 0.11, temperature 45.00°C, and incubation period 12.00 h. Under these conditions (substrate concentration 1.00%), the degree of hydrolysis (DH) was 35.06%. The free amino acids (FAAs) content of the EHBCs (35.24%) was 40.46 times higher than BCs while the total amino acids (TAAs) content was lower than BCs. The scores of lysine (human 0.87; pig 0.97), valine (human 1.42; pig 1.38), leucine (human 1.50; pig 1.90), tyrosine (human 0.84; pig 1.09), and histidine (human 2.17; pig 2.50) indicated that the EHBCs basically fulfilled the adult human and pig nutritional requirements. The calculated protein efficiency ratios (C-PERs) of the EHBCs were 3.94, 6.19, 21.73, and 2.04. In summary, the EHBCs were produced successfully with optimized conditions and could be a novel protein source for humans and pigs.

Software sensors design for the simultaneous saccharification and fermentation of starch to ethanol

A local analysis of stability and observability of the ethanol process are determined for continuous operation. It is found that the process is stable and noncompletely observable in the selected steady states. The analysis of observability was studied in terms of the observability matrix rank conditions. Furthermore, we design a nonlinear observer in order to estimate the observable state variables. The software sensor (state estimator) is developed considering only one measurable variable, the glucose concentration, and taking in account model uncertainties, which is a realistic issue. Some sufficient conditions for the existence of the proposed observer are obtained, which guarantee the convergence of the proposed methodology. The maximum ethanol production conditions are obtained by manipulating the dilution rate with optimal initial substrate concentration and the observable subspace is determinate which allows estimating six state variables (starch concentration, susceptible starch concentration, ethanol concentration, biomass concentration, glucose concentration and enzyme concentration). Numerical simulations are provided to show the effectiveness of the proposed observer where a comparison with a standard sliding-mode observer is done.

Biocatalytic anti-Prelog stereoselective reduction of ethyl acetoacetate catalyzed by whole cells of Acetobacter sp. CCTCC M209061

The biocatalytic anti-Prelog stereoselective reduction of ethyl acetoacetate (EAA) to ethyl (R)-3-hydroxybutyrate {(R)-EHB} was successfully conducted in the aqueous system using immobilized Acetobacter sp. CCTCC M209061 cells. Among various microorganisms tested, Acetobacter sp. CCTCC M209061 gave the best performance and showed great potential for the bioreduction of EAA to (R)-EHB. Acetobacter sp. CCTCC M209061 cells were immobilized on calcium alginate and then coated with chitosan, and the immobilized cells clearly surpassed the free cells in terms of better thermal stability, storability and recyclability. The optimal co-substrate for the reaction was found to be glucose. The optimal substrate concentration, buffer pH, glucose concentration, reaction temperature, biocatalyst concentration and shaking speed were 35.0mmol/L, 5.5, 80.0mmol/L, 35°C, 0.45g/mL and 200rpm, respectively. Under the optimized conditions, the initial reaction rate, the yield and the enantiomeric excess (e.e.) of the product were 1.28μmol/min, 82.6% and above 99.0%, respectively, which were much higher than those reported previously. The efficient whole-cell biocatalytic process was feasible on a 500-mL preparative scale, and the immobilized cells showed excellent operational stability and could be re-used for at least 10 batches. Additionally, the product e.e. constantly remained above 99.0% regardless of re-use cycles of the biocatalyst.

Bioconversion of de-oiled Jatropha Waste (DJW) to hydrogen and methane gas by anaerobic fermentation: Influence of substrate concentration, temperature and pH

Cellulosic materials-based de-oiled Jatropha Waste (DJW) was fermented to H2 and CH4 using sewage sludge inoculum. Batch assays were performed at various substrate concentrations (40–240 g/L), temperatures (25–65 °C) and pHs (5.5–7.5). The peak hydrogen production rate (HPR) and hydrogen yield (HY) of 744.0 ± 11.3 mL H2/L-d and 10.6 ± 0.2 mL H2/g VS obtained when the optimal substrate concentration, pH, temperature were 200 g/L, 6.5, 55 °C, respectively. The peak methane production rate (MPR) of 178.4 ± 5.6 mL CH4/L-d obtained while DJW concentration, pH, temperature were 200 g/L, 7.0, 45 °C, however, peak methane yield (MY) of 23.3 ± 0.1 mL CH4/g VS obtained at 40 g/L, 7.0 and 55 °C, respectively. Effect of substrate concentration on HPR and MPR was elucidated using Monod model. Butyrate and acetate were the main soluble metabolic products. Maximal carbohydrate removal and COD reduction were achieved as 51.7 ± 0.7% and 68.3 ± 1.6%, respectively.

CK2 Enzyme Affinity Against c-myc424-434Substrate in Human Lung Cancer Tissue

CK2 is a serine threonine kinase that participates in a variety of cellular processes with more than 300 defined substrates. This critical enzyme is known to be upregulated in cancers, but the role of this upregulation in carcinogenesis is not yet fully understood but c-myc, one of the defined CK2 substrates, is a well-known proto- oncogene that is normally essential in developmental process but is also involved in tumor development. We evaluated the optimal enzyme and substrate concentrations for CK2 activity in both neoplastic and non-neoplastic human lung tissues using the c-myc 424-434 peptide (EQKLISEEDL) as a substrate. The activities measured for the neoplastic tissue were 600-750 U/mg protein while those for the control tissue was in the range of 650-800 U/ mg. Km value for c-myc peptide was determined as 0.33 μM in non-neoplastic tissue and 0.18 μM in neoplastic tissue. In this study, we did not observe an increased activity in the neoplastic tissue when compared with the non-neoplastic lung tissue, but we recorded two times higher affinity for c-myc 424-434 in cancer tissue. Considering the metabolic position of c-myc 424-434, our results suggest that phosphorylation by CK2 may be important in dimerization and thus it might affect the regulation of c-myc in cancer tissues.

Enzymatic GST levels and overall health of mullets from contaminated Brazilian Lagoons

Glutathione S-transferase (GST) assays in non-mammalian organisms are usually conducted inappropriately, since no previous standardization of the optimal concentrations of proteins and substrates and adequate pH is conducted. Standardization is a key task to adjust enzyme assays at their kinetically correct maximal initial velocities, if one wants these velocities to indicate the amount of enzyme in a sample. In this paper GST assays were standardized in liver cytosol to compare seasonal GST levels in liver of mullet from two contaminated lagoons in the Rio de Janeiro to those from a reference bay. GST potential as a biomarker of sublethal intoxication in this species was also evaluated. Mullet liver GST levels assayed with substrates that corresponded to three different GST isoenzymes varied throughout the year. The differences indicated that mullets are suffering from sublethal intoxication from contaminants in these lagoons. Seasonal variations of activity were relevant, since these could indicate differences in xenobiotic input into the areas. An analysis of overall mullet health condition using a morphological index (the Fulton Condition Factor) and macroscopic abnormalities corroborated the differences in GST levels, with fish from one of the sites in worse overall health condition showing lower and significantly different FCF when compared to the reference site. Therefore, GST standardized activity levels are useful biomarkers of environmental contamination for mullet.

Tsukamurella sp. E105 as a new biocatalyst for highly enantioselective hydrolysis of ethyl 2-(2-oxopyrrolidin-1-yl) butyrate

A new bacterial strain, E105, has been introduced as a biocatalyst for the enantioselective hydrolysis of ethyl (R,S)-2-(2-oxopyrrolidin-1-yl) butyrate, (R,S)-1, to (S)-2-(2-oxopyrrolidin-1-yl) butyric acid, (S)-2. This strain was isolated from 60 soil samples using (R,S)-1 as the sole carbon source. The isolate was identified as Tsukamurella tyrosinosolvens E105, based on its morphological characteristics, physiological tests, and 16S rDNA sequence analysis. The process of cell growth and hydrolase production for this strain was then investigated. The hydrolase activity reached its maximum after cultivation at 200rpm and 30°C for 36h. Furthermore, the performance of the enantioselective hydrolysis of (R,S)-1 was studied. The optimal reaction temperature, initial pH, substrate concentration, and concentration of suspended cells were 30°C, 6.8, 10 and 30g/l (DCW), respectively. Under these conditions, a high conversion (>45%) of the product (S)-2 with an excellent enantiomeric excess (ee) (>99%), and a satisfied enantiomeric ratio (E) (>600) as well were obtained. This study showed that the bacterial isolate T. tyrosinosolvens E105 displayed a high enantioselectivity towards the hydrolysis of racemic ethyl 2-(2-oxopyrrolidin-1-yl) butyrate.

Efficient anti-Prelog enantioselective reduction of acetyltrimethylsilane to (R)-1-trimethylsilylethanol by immobilized Candida parapsilosis CCTCC M203011 cells in ionic liquid-based biphasic systems.

BackgroundBiocatalytic asymmetric reductions with whole cells can offer high enantioselectivity, environmentally benign processes and energy-effective operations and thus are of great interest. The application of whole cell-mediated bioreduction is often restricted if substrate and product have low water solubility and/or high toxicity to the biocatalyst. Many studies have shown that a biphasic system is often useful in this instance. Hence, we developed efficient biphasic reaction systems with biocompatible water-immiscible ionic liquids (ILs), to improve the biocatalytic anti-Prelog enantioselective reduction of acetyltrimethylsilane (ATMS) to (R)-1-trimethylsilylethanol {(R)-1-TMSE}, which is key synthon for a large number of silicon-containing drugs, using immobilized Candida parapsilosis CCTCC M203011 cells as the biocatalyst.ResultsIt was found that the substrate ATMS and the product 1-TMSE exerted pronounced toxicity to immobilized Candida parapsilosis CCTCC M203011 cells. The biocompatible water-immiscible ILs can be applied as a substrate reservoir and in situ extractant for the product, thus greatly enhancing the efficiency of the biocatalytic process and the operational stability of the cells as compared to the IL-free aqueous system. Various ILs exerted significant but different effects on the bioreduction and the performances of biocatalysts were closely related to the kinds and combination of cation and anion of ILs. Among all the water-immiscible ILs investigated, the best results were observed in 1-butyl-3-methylimidazolium hexafluorophosphate (C4mim·PF6)/buffer biphasic system. Furthermore, it was shown that the optimum substrate concentration, volume ratio of buffer to IL, buffer pH, reaction temperature and shaking rate for the bioreduction were 120 mM, 8/1 (v/v), 6.0, 30°C and 180 r/min, respectively. Under these optimized conditions, the initial reaction rate, the maximum yield and the product e.e. were 8.1 μmol/min gcwm, 98.6% and >99%, respectively. The efficient whole-cell biocatalytic process was shown to be feasible on a 450-mL scale. Moreover, the immobilized cells remained around 87% of their initial activity even after being used repeatedly for 8 batches in the C4mim·PF6/buffer biphasic system, exhibiting excellent operational stability.ConclusionsFor the first time, we have successfully utilized immobilized Candida parapsilosis CCTCC M203011 cells, for efficiently catalyzing anti-Prelog enantioselective reduction of ATMS to enantiopure (R)-1-TMSE in the C4mim·PF6/buffer biphasic system. The substantially improved biocatalytic process appears to be effective and competitive on a preparative scale.