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BACKGROUND: The increasing demand for sustainable alternatives to traditional protein sources, driven by population growth, underscores the importance of protein in a healthy diet. Pecan (Carya illinoinensis (Wangenh.) K. Koch) nuts are currently underutilized as plant‐based proteins but hold great potential in the food industry. However, there is insufficient information available on pecan protein, particularly its protein fractions. This study aimed to explore the physicochemical and functional properties of protein isolate and the main protein fraction glutelin extracted from pecan nuts. RESULTS: The results revealed that glutelin (820.67 ± 69.42 g kg−1) had a higher crude protein content compared to the protein isolate (618.43 ± 27.35 g kg−1), while both proteins exhibited amino acid profiles sufficient for adult requirements. The isoelectric points of protein isolate and glutelin were determined to be pH 4.0 and pH 5.0, respectively. The denaturation temperature of the protein isolate (90.23 °C) was higher than that of glutelin (87.43 °C), indicating a more organized and stable conformation. This is further supported by the fact that the protein isolate had a more stable main secondary structure than glutelin. Both proteins demonstrated improved solubility, emulsifying, and foaming properties at pH levels deviating from their isoelectric points in U‐shaped curves. Compared to the protein isolate, glutelin displayed superior water and oil absorption capacity along with enhanced gelling ability. CONCLUSION: The protein isolate and glutelin from pecan nuts exhibited improved stability and competitive functional properties, respectively. The appropriate utilization of these two proteins will support their potential as natural ingredients in various food systems. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Summary: The hypolipidemic effect of soymilk fermented by Lactiplantibacillus plantarum X7021, which is a novel strain isolated from the brine of stinky tofu, on high‐fat‐diet (HFD)‐induced hyperlipidemic mice was studied. The fermented soymilk could significantly inhibit 3‐hydroxy‐3‐methyl glutaryl coenzyme A reductase (HMGR) in vitro, and lower 23.8% total cholesterol, 45.5% triglyceride, and 15.4% low density lipoprotein cholesterol and increase 31.1% high density lipoprotein cholesterol in hyperlipidemic mice serum at the end of 4 w administration period. At the same time, the oxidative stress in hyperlipidemic mice was nearly alleviated to normal level. Furthermore, the bile salt hydrolase produced by the strain, the key enzymes, hormones and transcriptional regulators involved in hepatic lipids metabolism, faecal short chain fatty acids contents, and the abundance and diversity of gut microbiota in hyperlipidemic mice were analysed, verifying that the fermented soymilk ameliorated hyperlipidemia through the degradation of bile salts, modulating lipids metabolism and influencing gut microbiota. Consequently, this fermented soymilk is prospective in the functional food for the hypolipidemic application. [ABSTRACT FROM AUTHOR]

BACKGROUND Ginkgo biloba seeds are well known for the significant curative effects on relieving cough and asthma. However, the development of products from ginkgo seeds still falls behind at present, resulting in a great waste of ginkgo seeds' resource. In this work, submerged fermentation of ginkgo seed powder using Eurotium cristatum was studied to investigate its feasibility as a new processing method. RESULTS: To promote the growth of E. cristatum, the optimum fermentation medium was 80.0 g L−1 of ginkgo seed powder with addition of 5.0 g L−1 calcium chloride (CaCl2), 4.0 g L−1 magnesium sulfate (MgSO4), 1.25 g L−1 zinc sulfate (ZnSO4) and 0.65 g L−1 iron(II) sulfate (FeSO4). The optimum fermentation conditions were pH 5.8 ± 0.1, inoculum size 5.1 × 106 CFU mL−1, liquid medium volume 100 mL in 250‐mL Erlenmeyer flask and fermentation 4 days. Through fermentation, the production of lovastatin in fermentation broth could reach up to 32.97 ± 0.17 μg mL−1 and the total antioxidant capacity was improved by more than two‐fold. In addition, 40.15% of the ginkgotoxin in ginkgo seed powder was degraded while the entire degradation of ginkgolic acids was obtained. Moreover, fermented ginkgo seed powder suspension presented pleasant fragrances, and the activities of amylase and protease were enhanced to 11.30 ± 0.10 U mL−1 and 23.01 ± 0.20 U mL−1, respectively. CONCLUSIONS: Submerged fermentation using E. cristatum could significantly enhance the functional value and safety of ginkgo seed powder, and had great potential to become a novel processing method for the development of ginkgo seeds fermented products. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Ginkgotoxin including 4′‐O‐methylpyridoxine (MPN) and MPN‐5′‐glucoside (MPNG) is responsible for Ginkgo seed food poisoning. The purpose of the work reported was to prepare detoxified Ginkgo seed powder and at the same time to retain the nutritional and functional components of Ginkgo seed powder to the maximum extent. RESULTS: Resin adsorption technology was firstly employed to remove ginkgotoxin from water extract of Ginkgo seed powder. Under optimal conditions, the adsorption efficiency of the optimal resin for MPN could reach 100%, and that for MPNG could only reach 85.4 ± 0.93%. Resin adsorption alone could not effectively remove MPN and MPNG simultaneously. Endogenous enzymatic hydrolysis was next attempted to transform MPNG to MPN. MPNG could be completely hydrolyzed to MPN by endogenous enzyme(s) at 40 °C and pH 5.0 in 180 min. Ginkgotoxin only in the form of MPN in the enzymatic hydrolysate was then adsorbed with resin and the conditions were statistically optimized. The adsorption efficiency of MPN reached 98.89 ± 0.99% under the optimized conditions. CONCLUSIONS: Removal of ginkgotoxin by combining endogenous enzymatic hydrolysis with resin adsorption could preserve the main nutritional and functional components of Ginkgo seed powder to the most extent, and did not change its main characteristics. The ginkgotoxin removal method developed in this work is a relatively simple and efficient approach. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND: Recombinant pyruvate oxidase (pod) is in high demand owing to its broad application in biochemical analysis and low yield from wild microbial strains. Recombinant Escherichia coli harboring pET28a‐pod is an efficient producer of pod, facilitating its production in high yield. Optimizing cultivation using shake flasks is necessary for high‐level soluble pod production. RESULTS: During recombinant E. coli cultivation, 96.9% of pod activity was lost, and 3.1% of residual pod activity remained in a 25 mL working volume in 250 mL flasks owing to accumulation of pod in insoluble inclusion bodies. pH stress was the factor responsible for this phenomenon based on investigating dissolved oxygen and carbon source addition. Residual pod activity was increased to 43.3, 88.0 and 61.5% by maintaining the pH at 5.0, 6.0 and 7.0 respectively during the induction phase, which decreased inclusion body formation and increased production of soluble pod. Glycerol addition increased the cell density and volumetric pod activity to 21 243.3 U L−1 at pH 6.0 after 64 h induction. CONCLUSION: Soluble pod is converted to inclusion bodies under pH stress conditions, and this can be avoided by pH maintenance. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Nitrilase from Arthrobacter aurescens CYC705 can hydrolyze the iminodiacetonitrile to iminodiacetic acid (IDA) efficiently, and its high-level production in Escherichia coli has not been established. In the present work, the production of this nitrilase expressed in E. coli BL21(DE3) with a recombinant plasmid pET28a-cyc705 was optimized. Various culture conditions and process parameters including medium components and concentrations, inducer types and concentrations, inducing temperature and time were systematically examined in a shake flask. After optimization, the OD600, nitrilase activity, and productivity were obviously improved and achieved to 40.91 ± 1.341, 98.12 ± 1.248 U/mL, and 2,230 ± 28.36 U L−1 H−1, respectively, about 2.1-, 30-, and 33-fold increases as compared with those in the primary medium. Furthermore, four different fermentation strategies were adopted to scale up cultivation of the recombinant E. coli BL21(DE3)/pET28a-cyc705 in a 3.7-L fermenter. Substituting the peanut powder with fish peptone and accompanying with 1.0% glycerol feeding could significantly reduce the bubble production and shorten the fermentation time, which resulted in a nitrilase productivity of 4,653 ± 38.16 U L−1 H−1 that was about two times higher than that in a shake flask. The high-level production of A. aurescens CYC705 nitrilase established in this study will meet the need of industrial biosynthesis of IDA. [ABSTRACT FROM AUTHOR]

Serratia marcescens lipase ( Sm L) is an important biocatalyst used to enantioselectively hydrolyze (±)- trans-3-(4-methoxyphynyl) glycidic acid methyl ester. However, the economically justified level recombinant soluble expression of Sm L in Escherichia coli has not been established. Thus, fusion genes of lipase from S. marcescens H30 with different fusion tags were constructed and expressed in E. coli. The effects of fusion tags were revealed. A significant increase in recombinant lipase solubility showed that E. coli BL21 ( DE3)/p ET32a- Sm L was a suitable choice for Sm L production. To optimize the performance of recombinant Sm L production, changes in culture medium compositions and induction conditions were systematically tested. Finally, the recombinant Sm L activity and productivity reached approximately 23,000 U/L and 1,278 U/L/H in shake flasks, respectively. This value is the highest Sm L activity attained by heterogeneous recombinant expression in E. coli. Lipase activity and productivity reached 19,650 U/L and 1,228 U/L/H, respectively, by scaling up Sm L production in a 7.0 L fermenter. The existence of the Trx tag did not influence the chiral selectivity of recombinant Sm L. These findings indicate a possibility for soluble and economical Sm L expression in E. coli to meet industrial needs. [ABSTRACT FROM AUTHOR]

An efficient synthesis of the ( S)-3-amino-3-phenylpropanoic acid enantiomer has been achieved by Carica papaya lipase (CPL) catalysed enantioselective alcoholysis of the corresponding racemic N-protected 2,2,2-trifluoroethyl esters in an organic solvent. A high enantioselectivity ( E > 200) was achieved by two strategies that involved engineering of the substrates and optimization of the reaction conditions. Based on the resolution of a series of amino acids, it was found that the structure of the substrate has a profound effect on the CPL-catalysed resolution. The enantioselectivity and reaction rate were significantly enhanced by switching the conventional methyl ester to an activated trifluoroethyl ester. When considering steric effects, the substituted phenyl and amino groups should not both be large for the CPL-catalysed resolution. The mechanism of the CPL-catalysed enantioselective alcoholoysis of the amino acids is discussed to delineate the substrate requirements for CPL-catalysed resolution. Finally, the reaction was scaled up, and the products were separated and obtained in good yields (≥ 80 %). The ( S)-3-amino-3-phenylpropanoic acid obtained was used as a key chiral intermediate in the synthesis of ( S)-dapoxetine with very high enantiomeric excess (> 99 %). [ABSTRACT FROM AUTHOR]

In this work, fatty acid ethyl esters were produced from the lipase-catalyzed irreversible transesterification reaction between Jatropha oil and diethyl carbonate (DEC). Response surface methodology (RSM) based on central composite design (CCD) was used to optimize the five important reaction variables for the irreversible transesterification of Jatropha oil in a solvent-free system. The optimum conditions for the transesterification were a reaction time of 13.3 h, a temperature of 44.5 °C, a lipase amount of 13.7% (w/w), a DEC to Jatropha oil molar ratio of 3.75:1 and no need for adding water. The optimal predicted yield of fatty acid esters was 97.7% and the actual value was 96.2%. The results showed that the RSM based on CCD was adaptable for a fatty acid esters yield study for the current transesterification system. [ABSTRACT FROM AUTHOR]

The nitrilase mediated enantioselective hydrolysis is combined with an in situ racemization. [ABSTRACT FROM AUTHOR]