Development of New Multi-Glycosylation Routes to Facilitate the Biosynthesis of Sweetener Mogrosides from Bitter Immature Using Engineered .

Mogrosides, which have various pharmacological activities, are mainly extracted from (Luo Han Guo) and are widely used as natural zero-calorie sweeteners. Unfortunately, the difficult cultivation and long maturation time of Luo Han Guo have contributed to a shortage of mogrosides. To overcome this obstacle, we developed a highly efficient biosynthetic method using engineered to synthesize sweet mogrosides from bitter mogrosides.

Production and pharmaceutical research of minor saponins in Panax notoginseng (Sanqi): Current status and future prospects.

Panax notoginseng (Burk.) F.H.

Biotransformation approach to produce rare ginsenosides F1, compound Mc1, and Rd2 from major ginsenosides.

The stems and leaves of Panax notoginseng contain high saponins, but they are often discarded as agricultural waste. In this study, the predominant ginsenosides Rg1, Rc, and Rb2, presented in the stems and leaves of ginseng plants, were biotransformed into value-added rare ginsenosides F1, compound Mc1 (C-Mc1), and Rd2, respectively. A fungal strain YMS6 (Penicillium sp.

Biotransformation of Sclareol by a Fungal Endophyte of Salvia sclarea.

Microbial endophytes are known as versatile producers of useful metabolites, which have extensive applications in pharmacy, fragrance, agriculture and food. This study aims to screen sclareol-biotransforming microorganisms from Salvia sclarea, an untapped source of diverse endophytes. In this study, 50 culturable endophytes were isolated from S.

Efficient biosynthesis of resveratrol via combining phenylalanine and tyrosine pathways in Saccharomyces cerevisiae.

Background: Resveratrol is a commercially available stilbenoid widely used as dietary supplements, functional food ingredients, and cosmetic ingredients due to its diverse physiological activities. The production of resveratrol in microorganisms provides an ideal source that reduces the cost of resveratrol, but the titer in Saccharomyces cerevisiae was still much lower than that in other hosts.

Results: To achieve enhanced production of resveratrol in S.

High-yield production of protopanaxadiol from sugarcane molasses by metabolically engineered Saccharomyces cerevisiae.

Background: Ginsenosides are Panax plant-derived triterpenoid with wide applications in cardiovascular protection and immunity-boosting. However, the saponins content of Panax plants is fairly low, making it time-consuming and unsustainable by direct extraction. Protopanaxadiol (PPD) is a common precursor of dammarane-type saponins, and its sufficient supply is necessary for the efficient synthesis of ginsenoside.

Probing the Biotransformation Process of Sclareol by Resting Cells of .

Sclareol glycol is a key starting material with significant market interest for synthesizing high-value ambroxide, a sustainable substitute for ambergris in high-end fragrances. Sclareol glycol can be obtained by biotransformation of sclareol, a labdane-type diterpene, using . However, the pathway and mechanism of sclareol glycol biosynthesis remain unclear.

Biosynthesis of D--Hydroxyphenylglycine by a Designed Cofactor Self-Sufficient Route and Co-culture Strategy.

d--Hydroxyphenylglycine (D-HPG) is an important intermediate for the synthesis of β-lactam antibiotics with an annual market demand of thousands of tons. Currently, the main production processes are via chemical approaches. Although enzymatic conversion has been investigated for D-HPG production, synthesis of the substrate DL-hydroxyphenylhydantoin is still chemically based, which suffers from high pollution and harsh reaction conditions.

A Green Route for High-Yield Production of Tetramethylpyrazine From Non-Food Raw Materials.

2,3,5,6-Tetramethylpyrazine (TMP) is an active pharmaceutical ingredient originally isolated from for curing cardiovascular and cerebrovascular diseases and is widely used as a popular flavoring additive in the food industry. Hence, there is a great interest in developing new strategies to produce this high-value compound in an ecological and economical way. Herein, a cost-competitive combinational approach was proposed to accomplish green and high-efficiency production of TMP.

Characterization of a Group of UDP-Glycosyltransferases Involved in the Biosynthesis of Triterpenoid Saponins of .

UDP-glycosyltransferase (UGT)-mediated glycosylation is a common modification in triterpene saponins, which exhibit a wide range of bioactivities and important pharmacological effects. However, few UGTs involved in saponin biosynthesis have been identified, limiting the biosynthesis of saponins. In this study, an efficient heterologous expression system was established for evaluating the UGT-mediated glycosylation process of triterpene saponins.

Biosynthesis of Polydatin in .

Polydatin, with better structural stability and biological activities than resveratrol, is mainly extracted from the traditional Chinese medicinal plant . In this study, based on the transcriptome analysis of , we identified the key glycosyltransferase of resveratrol and achieved the biosynthesis of polydatin from glucose by incorporation with the resveratrol biosynthesis module, UDP-glucose supply module, and glycosyltransferase expression module. Through metabolic engineering and fermentation optimization, the production of polydatin reached 545 mg/L, and the dry cell weight was 27.

Biological Production of (S)-acetoin: A State-of-the-Art Review.

Acetoin is an important four-carbon compound that has many applications in foods, chemical synthesis, cosmetics, cigarettes, soaps, and detergents. Its stereoisomer (S)-acetoin, a high-value chiral compound, can also be used to synthesize optically active drugs, which could enhance targeting properties and reduce side effects. Recently, considerable progress has been made in the development of biotechnological routes for (S)-acetoin production.

Simulated Protein Thermal Detection (SPTD) for Enzyme Thermostability Study and an Application Example for Pullulanase from Bacillus deramificans.

Background: The relationship between protein structure and its bioactivity is one of the fundamental problems for protein engineering and pharmaceutical design.

Method: A new method, called SPTD (Simulated Protein Thermal Detection), was proposed for studying and improving the thermal stability of enzymes. The method was based on the evidence observed by conducting the MD (Molecular Dynamics) simulation for all the atoms of an enzyme vibrating from the velocity at a room temperature (e.

Enhanced production of optical ()-acetoin by a recombinant whole-cell biocatalyst with NADH regeneration.

Acetoin is an important platform chemical with a variety of applications in foods, cosmetics, chemical synthesis, and especially in the asymmetric synthesis of optically active pharmaceuticals. It is also a useful breath biomarker for early lung cancer diagnosis. In order to enhance production of optical ()-acetoin and facilitate this building block for a series of chiral pharmaceuticals derivatives, we have developed a systematic approach using -NADH regeneration systems and promising diacetyl reductase.

Fabrication and Characterization of Graphene Microcrystal Prepared from Lignin Refined from Sugarcane Bagasse.

Graphene microcrystal (GMC) is a type of glassy carbon fabricated from lignin, in which the microcrystals of graphene are chemically bonded by sp³ carbon atoms, forming a glass-like microcrystal structure. The lignin is refined from sugarcane bagasse using an ethanol-based organosolv technique which is used for the fabrication of GMC by two technical schemes: The pyrolysis reaction of lignin in a tubular furnace at atmospheric pressure; and the hydrothermal carbonization (HTC) of lignin at lower temperature, followed by pyrolysis at higher temperature. The existence of graphene nanofragments in GMC is proven by Raman spectra and XRD patterns; the ratio of sp² carbon atoms to sp³ carbon atoms is demonstrated by XPS spectra; and the microcrystal structure is observed in the high-resolution transmission electron microscope (HRTEM) images.

A comparative study for the organic byproducts from hydrothermal carbonizations of sugarcane bagasse and its bio-refined components cellulose and lignin.

Sugarcane bagasse was refined into cellulose, hemicellulose, and lignin using an ethanol-based organosolv technique. The hydrothermal carbonization (HTC) reactions were applied for bagasse and its two components cellulose and lignin. Based on GC-MS analysis, 32 (13+19) organic byproducts were derived from cellulose and lignin, more than the 22 byproducts from bagasse.

2L-PCA: a two-level principal component analyzer for quantitative drug design and its applications.

A two-level principal component predictor (2L-PCA) was proposed based on the principal component analysis (PCA) approach. It can be used to quantitatively analyze various compounds and peptides about their functions or potentials to become useful drugs. One level is for dealing with the physicochemical properties of drug molecules, while the other level is for dealing with their structural fragments.

Microbial Routes to (2R,3R)-2,3-Butanediol: Recent Advances and Future Prospects.

(2R,3R)-2,3-Butanediol has many industrial applications, such as it is used as an antifreeze agent and low freezing point fuel. In addition, it is particularly important to provide chiral groups in drugs. In recent years, this valuable bio-based chemical has attracted increasing attention, and significant progress has been made in the development of microbial cell factories for (2R,3R)-2,3-butanediol production.

The Intrinsic Relationship Between Structure and Function of the Sialyltransferase ST8Sia Family Members.

As a subset of glycosyltransferases, the family of sialyltransferases catalyze transfer of sialic acid (Sia) residues to terminal non-reducing positions on oligosaccharide chains of glycoproteins and glycolipids, utilizing CMP-Neu5Ac as the activated sugar nucleotide donor. In the four known sialyltransferase families (ST3Gal, ST6Gal, ST6GalNAc and ST8Sia), the ST8Sia family catalyzes synthesis of α2, 8-linked sialic/polysialic acid (polySia) chains according to their acceptor specificity. We have determined the 3D structural models of the ST8Sia family members, designated ST8Sia I (1), II(2), IV(4), V(5), and VI(6) using the Phyre2 server.

Exploring the possibility to store the mixed oxygen-hydrogen cluster in clathrate hydrate in molar ratio 1:2 (O+2H).

An interesting possibility is explored: storing the mixture of oxygen and hydrogen in clathrate hydrate in molar ratio 1:2. The interaction energies between oxygen, hydrogen, and clathrate hydrate are calculated using high level quantum chemical methods. The useful conclusion points from this study are summarized as follows.

Active Hydrogen Bond Network (AHBN) and Applications for Improvement of Thermal Stability and pH-Sensitivity of Pullulanase from Bacillus naganoensis.

A method, so called "active hydrogen bond network" (AHBN), is proposed for site-directed mutations of hydrolytic enzymes. In an enzyme the AHBN consists of the active residues, functional residues, and conservative water molecules, which are connected by hydrogen bonds, forming a three dimensional network. In the catalysis hydrolytic reactions of hydrolytic enzymes AHBN is responsible for the transportation of protons and water molecules, and maintaining the active and dynamic structures of enzymes.

A new type of two-dimensional carbon crystal prepared from 1,3,5-trihydroxybenzene.

A new two-dimensional (2D) carbon crystal, different from graphene, has been prepared from 1,3,5-trihydroxybenzene, consisting of 4-carbon and 6-carbon rings in 1:1 ratio, named 4-6 carbophene by authors, in which all carbon atoms possess sp hybrid orbitals with some distortion, forming an extensive conjugated π-bonding planar structure. The angles between the three σ-bonds of the carbon sp orbitals are roughly 120°, 90°, and 150°. Each of the three non-adjacent sides of a 6C-ring is shared with a 4C-ring; and each of the two opposite sides of a 4C-ring is shared with a 6C-ring.

Promoter Screening from Bacillus subtilis in Various Conditions Hunting for Synthetic Biology and Industrial Applications.

The use of Bacillus subtilis in synthetic biology and metabolic engineering is highly desirable to take advantage of the unique metabolic pathways present in this organism. To do this, an evaluation of B. subtilis' intrinsic biological parts is required to determine the best strategies to accurately regulate metabolic circuits and expression of target proteins.

Fermentative production of enantiomerically pure S-1,2-propanediol from glucose by engineered E. coli strain.

The pure stereoisomers of 1,2-propanediol (1,2-PDO) could be used as starting materials to synthesize high value-added specialty chemicals and chiral pharmaceutical products. As the stereoisomers of 1,2-PDO cannot be obtained by traditional chemical synthesis processes, biotechnological processes have gained increasing attention. However, to our knowledge, the production of S-1,2-PDO directly from glucose has not been previously reported.