Ultrasound-Assisted Coupled with Resin-Based Purification for Sustainable Extraction of Steviosides from Leaves.

Stevioside, a natural high-intensity sweetener, is widely employed across the food, pharmaceutical, and daily chemical industries due to its intense sweetness and health benefits. However, traditional extraction and purification processes for steviol glycosides from are plagued by low efficiency, high energy consumption, substantial environmental impact, and inconsistent product quality. This study systematically optimized the extraction, decolorization, decontamination, and desalting processes to overcome these challenges.

Function and Engineering of a Food Enzyme Under Coupled High-Temperature-Pressure Conditions: Insights from Molecular Dynamics Simulation and Experimental Validation.

The relationship between protein structure and function is intrinsically interconnected, as the structure of a protein directly determines its functional properties. To investigate the effects of temperature and pressure on protein function, this study employed ethyl carbamate (EC) hydrolase as a model food enzyme and conducted molecular dynamics (MD) simulations under varying temperature and pressure levels to elucidate its structure-function relationship. By systematically analyzing the dynamic changes in root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration (Rg), solvent accessible surface area (SASA), hydrogen bonding, catalytic pocket conformation, and packing density under different temperature and pressure conditions, we revealed the structural adaptability of EC hydrolase.

Novel cytochrome P450s for various hydroxylation of steroids from filamentous fungi.

Hydroxylated steroids are value-added products with diverse biological activities mediated by cytochrome P450 enzymes, however, few has been thoroughly characterized in fungi. This study introduces a rapid identification strategy for filamentous fungi P450 enzymes through transcriptome and bioinformatics analysis. Five novel enzymes (CYP68J5, CYP68L10, CYP68J3, CYP68N1 and CYP68N3) were identified and characterized in Saccharomyces cerevisiae or Aspergillus oryzae.

Effective degradation of anthraquinones in with fermentation for toxicity reduce and efficacy enhancement.

are widely used around the world, mainly in purging and removal of endogenous active substances, such as anthraquinone and its derivatives. However, the potential toxicity of anthraquinones to the liver, kidney, and intestinal limits the application of . In this study, we aimed at safe regulation of to degrade anthraquinones, boosting medicinal properties and reducing toxicity and potency with fermentation strains H1102 for fermentation were selected as the initial strain which was capable of producing high yields of functional pigment and low yields of hazardous citrinin.

Behavior of enzymes under high pressure in food processing: mechanisms, applications, and developments.

High pressure processing (HPP) offers the benefits of safety, uniformity, energy-efficient, and low waste, which is widely applied for microbial inactivation and shelf-life extension for foods. Over the past forty years, HPP has been extensively researched in the food industry, enabling the inactivation or activation of different enzymes in future food by altering their molecular structure and active site conformation. Such activation or inactivation of enzymes effectively hinders the spoilage of food and the production of beneficial substances, which is crucial for improving food quality.

Redesign of γ-glutamyl transpeptidase from Bacillus subtilis for high-level production of L-theanine by cavity topology engineering.

L-Theanine is a multifunctional nonprotein amino acid found naturally in tea leaves. It has been developed as a commercial product for a wide range of applications in the food, pharmaceutical, and healthcare industries. However, L-theanine production catalyzed by γ-glutamyl transpeptidase (GGT) is limited by the low catalytic efficiency and specificity of this class of enzymes.

Improving ethanol tolerance of ethyl carbamate hydrolase by diphasic high pressure molecular dynamic simulations.

Ethyl carbamate (EC) is mainly found in fermented foods and fermented alcoholic beverages, which could cause carcinogenic potential to humans. Reducing EC is one of the key research priorities to address security of fermented foods. Enzymatic degradation of EC with EC hydrolase in food is the most reliable and efficient method.

Inside Out Computational Redesign of Cavities for Improving Thermostability and Catalytic Activity of Lipase.

Cavities are created by hydrophobic interactions between residue side chain atoms during the folding of enzymes. Redesigning cavities can improve the thermostability and catalytic activity of the enzyme; however, the synergistic effect of cavities remains unclear. In this study, Rhizomucor miehei lipase (RML) was used as a model to explore volume fluctuation and spatial distribution changes of the internal cavities, which could reveal the roles of internal cavities in the thermostability and catalytic activity.

Protein-Glutaminase Engineering Based on Isothermal Compressibility Perturbation for Enhanced Modification of Soy Protein Isolate.

Protein-glutaminase plays a significant role in future food (e.g., plant-based meat) processing as a result of its ability to improve the solubility, foaming, emulsifying, and gel properties of plant-based proteins.

PsrA is a novel regulator contributes to antibiotic synthesis, bacterial virulence, cell motility and extracellular polysaccharides production in Serratia marcescens.

Serratia marcescens is a Gram-negative bacterium of the Enterobacteriaceae family that can produce numbers of biologically active secondary metabolites. However, our understanding of the regulatory mechanisms behind secondary metabolites biosynthesis in S. marcescens remains limited.

Citrulline deiminase pathway provides ATP and boosts growth of Clostridium carboxidivorans P7.

Background: Clostridium carboxidivorans P7 is capable of producing ethanol and butanol from inexpensive and non-food feedstock, such as syngas. Achieving improved ethanol and butanol production in the strain for industrial application depends on the energetics and biomass, especially ATP availability.

Results: This study found that exogenous addition of citrulline promoted accumulation of ATP, increased specific growth rate, and reduced the doubling time of C.

MarR-type transcription factor RosR regulates glutamate metabolism network and promotes accumulation of L-glutamate in Corynebacterium glutamicum G01.

Transcription factors (TFs) perform a crucial function in the regulation of amino acids biosynthesis. Here, TFs involved in L-glutamate biosynthesis in Corynebacterium glutamicum were investigated. Compared to transcriptomic results of C.

Microbial production of riboflavin: Biotechnological advances and perspectives.

Riboflavin is an essential nutrient for humans and animals, and its derivatives flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) are cofactors in the cells. Therefore, riboflavin and its derivatives are widely used in the food, pharmaceutical, nutraceutical and cosmetic industries. Advances in biotechnology have led to a complete shift in the commercial production of riboflavin from chemical synthesis to microbial fermentation.

Enhanced Prodigiosin Production in JNB5-1 by Introduction of a Polynucleotide Fragment into the 3' Untranslated Region and Disulfide Bonds into -Methyl Transferase (PigF).

In Serratia marcescens JNB5-1, prodigiosin was highly produced at 30°C, but it was noticeably repressed at ≥37°C. Our initial results demonstrated that both the production and the stability of the -methyl transferase (PigF) and oxidoreductase (PigN) involved in the prodigiosin pathway in S. marcescens JNB5-1 sharply decreased at ≥37°C.

Metabolic engineering of Bacillus subtilis for enhancing riboflavin production by alleviating dissolved oxygen limitation.

Riboflavin, an essential vitamin for animals, is used widely in the pharmaceutical industry and as a food and feed additive. The microbial synthesis of riboflavin requires a large amount of oxygen, which limits the industrial-scale production of the vitamin. In this study, a metabolic engineering strategy based on transcriptome analysis was identified as effective in increasing riboflavin production.

Biochemical Characterization and Structural Insight into Interaction and Conformation Mechanisms of Lysine Decarboxylase (SmcadA).

Inducible lysine decarboxylases (LDCs) are essential in various cellular processes of microorganisms and plants, especially under acid stress, which induces the expression of genes encoding LDCs. In this study, a novel LDC (SmcadA) was successfully expressed in , purified and characterized. The protein had an optimal pH of 6 and a temperature of 40 °C and phylogenetic analysis to determine the evolution of SmcadA, which revealed a close relation to sp.

Identification of bottlenecks in 4-androstene-3,17-dione/1,4-androstadiene-3,17-dione synthesis by Mycobacterium neoaurum JC-12 through comparative proteomics.

Intermediates such as 4-androstene-3,17-dione (AD) and 1,4-androstadiene-3,17-dione (ADD) have extensive clinical applications in the production of steroid pharmaceuticals. The present study explores the effect of two factors in the production of these intermediates in Mycobacterium neoaurum JC-12: the precursor, phytosterol and a molecule that increases AD/ADD solubility, hydroxypropyl-β-cyclodextrin (HP-β-CD). Differentially expressed proteins were separated and identified using 2D gel electrophoresis (2-DE) and matrix assisted laser desorption/ionization time-of-flight/time-of-flight tandem mass spectrometry (MALDI-TOF/TOF-MS/MS).

Integrated gene engineering synergistically improved substrate-product transport, cofactor generation and gene translation for cadaverine biosynthesis in E. coli.

Several approaches for efficient production of cadaverine, a bio-based diamine with broad industrial applications have been explored. Here, Serratia marcescens lysine decarboxylase (SmcadA) was expressed in E. coli; mild surfactants added in biotransformation reactions; the E.

Regulator RcsB Controls Prodigiosin Synthesis and Various Cellular Processes in Serratia marcescens JNB5-1.

Prodigiosin (PG), a red linear tripyrrole pigment normally secreted by , has received attention for its reported immunosuppressive, antimicrobial, and anticancer properties. Although several genes have been shown to be important for prodigiosin synthesis, information on the regulatory mechanisms behind this cellular process remains limited. In this work, we identified that the transcriptional regulator RcsB encoding gene () negatively controlled prodigiosin biosynthesis in Disruption of conferred a remarkably increased production of prodigiosin.

Improved Prodigiosin Production by Relieving CpxR Temperature-Sensitive Inhibition.

Prodigiosin (PG) is a typical secondary metabolite mainly produced by . CpxR protein is an OmpR family transcriptional regulator in Gram-negative bacteria. Firstly, it was found that insertion mutation of in JNB 5-1 by a transposon Tn5G increased the production of PG.

Directed Evolution of Ornithine Cyclodeaminase Using an EvolvR-Based Growth-Coupling Strategy for Efficient Biosynthesis of l-Proline.

l-Proline takes a significant role in the pharmaceutical and chemical industries as well as graziery. Typical biosynthesis of l-proline is from l-glutamate, involving three enzyme reactions as well as a spontaneous cyclization. Alternatively, l-proline can be also synthesized in l-ornithine and/or l-arginine producing strains by an ornithine aminotransferase (OCD).

Loss of Serine-Type D-Ala-D-Ala Carboxypeptidase DacA Enhances Prodigiosin Production in .

, a gram-negative bacterium, found in a wide range of ecological niches can produce several high-value products, including prodigiosin, althiomycin, and serratamolide. Among them, prodigiosin has attracted attention due to its immunosuppressive, antimicrobial, and anticancer properties. However, the regulatory mechanisms behind prodigiosin synthesis in remains limited.

LysR-Type Transcriptional Regulator MetR Controls Prodigiosin Production, Methionine Biosynthesis, Cell Motility, HO Tolerance, Heat Tolerance, and Exopolysaccharide Synthesis in Serratia marcescens.

Prodigiosin, a secondary metabolite produced by , has attracted attention due to its immunosuppressive, antimicrobial, and anticancer properties. However, information on the regulatory mechanism behind prodigiosin biosynthesis in remains limited. In this work, a prodigiosin-hyperproducing strain with the gene disrupted (ZK66) was selected from a collection of TnG transposon insertion mutants.

Lys-Arg mutation improved the thermostability of Bacillus cereus neutral protease through increased residue interactions.

Neutral proteases have broad application as additives in modern laundry detergents and therefore, thermostability is an integral parameter for effective production of protein crystals. To improve thermostability, the contribution of individual residues of Bacillus cereus neutral protease was examined by site-directed mutagenesis. The Lys11Arg and Lys211Arg mutants clearly possessed improved thermostabilities (T were 63 and 61 °C respectively) compared to the wild-type (T was 60 °C).

Insight into the thermostability of thermophilic L-asparaginase and non-thermophilic L-asparaginase II through bioinformatics and structural analysis.

Thermostability plays an important role in the application of L-asparaginase in the pharmaceutical and food industries. Understanding the key residues and structures that influence thermostability in L-asparaginase is necessary to obtain suitable L-asparaginase candidates. In this study, special residues and structures that altered thermostability in thermophilic L-asparaginase and non-thermophilic L-asparaginase II were identified.