Production of Ginsenoside F2 by Using Lactococcus lactis with Enhanced Expression of β-Glucosidase Gene from Paenibacillus mucilaginosus

High efficiency biosynthesis of gardenia blue and red pigment by lactic acid bacteria: A great potential for natural color pigments

Current production methods of the food colorants, gardenia blue (GB) and red (GR) pigments have low efficiency. One potential approach involves using lactic acid bacteria (LAB), which produce a high level of β-glucosidase, produce the GB and GR using non-toxic and harmless process. The isolated strain Lactobacillus plantarum S3 and the reference strain Lb. plantarum KCTC3104 showed high β-glucosidase activity levels of 1.01 and 1.44 unit/mL, respectively. The 12-h bioconversion yield of geniposide to genipin using two strains were 93.4% and 100%, respectively, which are high conversion percentage. For GB, the maximal production yield obtained using Lb. plantarum S3 and Lb. plantarum KCTC3104 under optimal conditions were 2.17 and 2.18 mg/mL, respectively. For GR, glutamic acid (Glu) with Lb. plantarum S3 is the best combination. To the best of our knowledge, this is the first report of an effective alternative method for the production of natural food colorants using LAB.

Production of Prosaikogenin F, Prosaikogenin G, Saikogenin F and Saikogenin G by the Recombinant Enzymatic Hydrolysis of Saikosaponin and their Anti-Cancer Effect

The saponins of Bupleurum falcatum L., saikosaponins, are the major components responsible for its pharmacological and biological activities. However, the anti-cancer effects of prosaikogenin and saikogenin, which are glycoside hydrolyzed saikosaponins, are still unknown due to its rarity in plants. In this study, we applied two recombinant glycoside hydrolases that exhibit glycoside cleavage activity with saikosaponins. The two enzymes, BglPm and BglLk, were cloned from Paenibacillus mucilaginosus and Lactobacillus koreensis, and exhibited good activity between 30-37 °C and pH 6.5-7.0. Saikosaponin A and D were purified and obtained from the crude B. falcatum L. extract using preparative high performance liquid chromatography technique. Saikosaponin A and D were converted into saikogenin F via prosaikogenin F, and saikogenin G via prosaikogenin G using enzyme transformation with high β-glycosidase activity. The two saikogenin and two prosaikogenin compounds were purified using a silica column to obtain 78.1, 62.4, 8.3, and 7.5 mg of prosaikogenin F, prosaikogenin G, saikogenin F, and saikogenin G, respectively, each with 98% purity. The anti-cancer effect of the six highly purified saikosaponins was investigated in the human colon cancer cell line HCT 116. The results suggested that saikosaponins and prosaikogenins markedly inhibit the growth of the cancer cell line. Thus, this enzymatic technology could significantly improve the production of saponin metabolites of B. falcatum L.

Qualitatively and quantitatively investigating the metabolism of 20(S)-protopanaxadiol-type ginsenosides by gut microbiota of different species

Ginsenosides Rb1, Rb2, Rb3 and Rc, four major protopanaxadiol (PPD)-type ginsenosides, can be metabolized by gut microbiota. The composition of gut microbiota varies in different species. Existing publications have reported the metabolite fates of ginsenosides by gut microbiota from single species. However, their microbiota-related metabolic species differences have not been evaluated yet. In current study, in vitro anaerobic incubations of PPD-type ginsenosides with gut microbiota from humans, rabbits and rats were conducted. The metabolites of each ginsenoside were then identified by LC-MS. A total of 15 metabolites from the four ginsenosides were identified. The major metabolic pathways were stepwise removals of the C-20 and C-3 sugar moieties to obtain aglycone PPD. The results showed that the hydrolysis rate of C-20 terminal β-D-glucopyranosyl was significantly higher than those of α-L-arabinopyranosyl, β-D-xylopyranosyl and α-L-arabinofuranosyl in different species. The activity of β-glucosidase, the metabolic rates of parent compounds and the formation rates of their metabolites were significantly higher in gut microbiota from rabbits than from humans and rats. Our research draws researchers' attention to the species differences of microbiota-related drug metabolism.

Spectroscopic and in silico investigation of the interaction between GH1 β-glucosidase and ginsenoside Rb1

The function and application of β-glucosidase attract attention nowadays. β-glucosidase was confirmed of transforming ginsenoside Rb1 to rare ginsenoside, but the interaction mechanism remains not clear. In this work, β-glucosidase from GH1 family of Paenibacillus polymyxa was selected, and its gene sequence bglB was synthesized by codon. Then, recombinant plasmid was transferred into Escherichia coli BL21 (DE3) and expressed. The UV-visible spectrum showed that ginsenoside Rb1 decreased the polarity of the corresponding structure of hydrophobic aromatic amino acids (Trp) in β-glucosidase and increased new π-π* transition. The fluorescence quenching spectrum showed that ginsenoside Rb1 inhibited intrinsic fluorescence, formed static quenching, reduced the surface hydrophobicity of β-glucosidase, and KSV was 8.37 × 103 L/M (298K). Circular dichroism (CD) showed that secondary structure of β-glucosidase was changed by the binding action. Localized surface plasmon resonance (LSPR) showed that β-glucosidase and Rb1 had strong binding power which KD value was 5.24 × 10-4 (±2.35 × 10-5) M. Molecular docking simulation evaluated the binding site, hydrophobic force, hydrogen bond, and key amino acids of β-glucosidase with ginsenoside Rb1 in the process. Thus, this work could provide basic mechanisms of the binding and interaction between β-glucosidase and ginsenoside Rb1.

Advances in the Production of Minor Ginsenosides Using Microorganisms and Their Enzymes

Abstract Minor ginsenodes are of great interest due to their diverse pharmacological activities such as their anti-cancer, anti-diabetic, neuroprotective, immunomodulator, and anti-inflammatory effects. The miniscule amount of minor ginsenosides in ginseng plants has driven the development of their mass production methods. Among the various production methods for minor ginsenosides, the utilization of microorganisms and their enzymes are considered as highly specific, safe, and environmentally friendly. In this review, various minor ginsenosides production strategies, namely utilizing microorganisms and recombinant microbial enzymes, for biotransforming major ginsenosides into minor ginsenoside, as well as constructing synthetic minor ginsenosides production pathways in yeast cell factories, are described and discussed. Furthermore, the present challenges and future research direction for producing minor ginsenosides using those approaches are discussed.

Enzymatic Biotransformation of Ginsenoside Rb2 into Rd by Recombinant α-L-Arabinopyranosidase from Blastococcus saxobsidens

In this study, we used a novel α-L-arabinopyranosidase (AbpBs) obtained from ginsenoside-converting Blastococcus saxobsidens that was cloned and expressed in Escherichia coli BL21 (DE3), and then applied it in the biotransformation of ginsenoside Rb₂ into Rd. The gene, termed AbpBs, consisting of 2,406 nucleotides (801 amino acid residues), and with a predicted translated protein molecular mass of 86.4 kDa, was cloned into a pGEX4T-1 vector. A BLAST search using the AbpBs amino acid sequence revealed significant homology with a family 2 glycoside hydrolase (GH2). The over-expressed recombinant AbpBs in Escherichia coli BL21 (DE3) catalyzed the hydrolysis of the arabinopyranose moiety attached to the C-20 position of ginsenoside Rb2 under optimal conditions (pH 7.0 and 40°;C). Kinetic parameters for α-Larabinopyranosidase showed apparent K_m and V_max values of 0.078 ± 0.0002 micrometer and 1.4 ± 0.1 μmol/min/mg of protein against p-nitrophenyl-α-L-arabinopyranoside. Using a purified AbpBs (1 μg/ml), 0.1% of ginsenoside Rb₂ was completely converted to ginsenoside Rd within 1 h. The recombinant AbpBs could be useful for high-yield, rapid, and low-cost preparation of ginsenoside Rd from Rb₂.

Alternative strategies for lignocellulose fermentation through lactic acid bacteria: the state of the art and perspectives

Lactic acid bacteria (LAB) have a long history in industrial processes as food starters and biocontrol agents, and also as producers of high-value compounds. Lactic acid, their main product, is among the most requested chemicals because of its multiple applications, including the synthesis of biodegradable plastic polymers. Moreover, LAB are attractive candidates for the production of ethanol, polyhydroalkanoates, sweeteners and exopolysaccharides. LAB generally have complex nutritional requirements. Furthermore, they cannot directly ferment inexpensive feedstocks such as lignocellulose. This significantly increases the cost of LAB fermentation and hinders its application in the production of high volumes of low-cost chemicals. Different strategies have been explored to extend LAB fermentation to lignocellulosic biomass. Fermentation of lignocellulose hydrolysates by LAB has been frequently reported and is the most mature technology. However, current economic constraints of this strategy have driven research for alternative approaches. Co-cultivation of LAB with native cellulolytic microorganisms may reduce the high cost of exogenous cellulase supplementation. Special attention is given in this review to the construction of recombinant cellulolytic LAB by metabolic engineering, which may generate strains able to directly ferment plant biomass. The state of the art of these strategies is illustrated along with perspectives of their applications to industrial second generation biorefinery processes.

High-density immobilization of a ginsenoside-transforming β-glucosidase for enhanced food-grade production of minor ginsenosides

Use of recombinant glycosidases is a promising approach for the production of minor ginsenosides, e.g., Compound K (CK) and F₁, which have potential applications in the food industry. However, application of these recombinant enzymes for food-grade preparation of minor ginsenosides are limited by the lack of suitable expression hosts and low productivity. In this study, Corynebacterium glutamicum ATCC13032, a GRAS strain that has been used extensively for the industrial-grade production of additives for foodstuffs, was employed to express a novel β-glucosidase (MT619) from Microbacterium testaceum ATCC 15829 with high ginsenoside-transforming activity. A cellulose-binding module was additionally fused to the N-terminus of MT619 for immobilization on cellulose, which is an abundant and safe material. Via one-step immobilization, the fusion protein in cell lysates was efficiently immobilized on regenerated amorphous cellulose at a high density (maximum 984 mg/g cellulose), increasing the enzyme concentration by 286-fold. The concentrated and immobilized enzyme showed strong conversion activities against protopanaxadiol- and protopanaxatriol-type ginsenosides for the production of CK and F₁. Using gram-scale ginseng extracts as substrates, the immobilized enzyme produced 7.59 g/L CK and 9.42 g/L F₁ in 24 h. To the best of our knowledge, these are the highest reported product concentrations of CK and F₁, and this is the first time that a recombinant enzyme has been immobilized on cellulose for the preparation of minor ginsenosides. This safe, convenient, and efficient production method could also be effectively exploited in the preparation of food-processing recombinant enzymes in the pharmaceutical, functional food, and cosmetics industries.

Enzymatic Synthesis of Novel Glycyrrhizic Acid Glucosides Using a Promiscuous Bacillus Glycosyltransferase

Glycyrrhetinic acid (GA) and glycyrrhizin (GA-3-O-[β-d-glucuronopyranosyl-(1→2)-β-d-glucuronopyranoside], GL) are the major bioactive components of Glycyrrhiza uralensis and possess multifarious notable biological activities. UDP-glycosyltransferase (UGT)–catalyzed glycosylation remarkably extends the structural and functional diversification of GA-glycoside derivatives. In this study, six glucosides (1–6) of GA and GL were synthesized using a Bacillus subtilis 168–originated flexible UDP-glycosyltransferase Bs-YjiC. Bs-YjiC could transfer a glucosyl moiety from UDP-glucose to the free C3 hydroxyl and/or C30 carboxyl groups of GA and GL and further elongate the C30 glucosyl chain via a β-1-2-glycosidic bond. Glycosylation significantly increased the water solubility of these novel glucosides by 4–90 folds. In vitro assays showed that GA monoglucosides (1 and 2) showed stronger antiproliferative activity against human liver cancer cells HepG2 and breast cancer cells MCF-7 than that of GL and GL glucosides. These findings provide significant insights into the important role of promiscuous UGTs for the enzymatic synthesis of novel bioactive GA derivatives.

One-Pot Synthesis of Ginsenoside Rh2 and Bioactive Unnatural Ginsenoside by Coupling Promiscuous Glycosyltransferase from Bacillus subtilis 168 to Sucrose Synthase

Ginsenosides, the major effective ingredients of Panax ginseng, exhibit various biological properties. UDP-glycosyltransferase (UGT)-mediated glycosylation is the last biosynthetic step of ginsenosides and contributes to their immense structural and functional diversity. In this study, UGT Bs-YjiC from Bacillus subtilis 168 was demonstrated to transfer a glucosyl moiety to the free C3-OH and C12-OH of protopanaxadiol (PPD) and PPD-type ginsenosides to synthesize natural and unnatural ginsenosides. In vitro assays showed that unnatural ginsenoside F12 (3- O-β-d-glucopyranosyl-12- O-β-d-glucopyranosyl-20( S)-protopanaxadiol) exhibited remarkable activity against diverse human cancer cell lines. A one-pot reaction by coupling Bs-YjiC to sucrose synthase (SuSy) was performed to regenerate UDP-glucose from sucrose and UDP. With PPD as the aglycon, an unprecedented high yield of ginsenosides F12 (3.98 g L^-1) and Rh2 (0.20 g L^-1) was obtained by optimizing the conversion conditions. This study provides an efficient approach for the biosynthesis of ginsenosides using a UGT-SuSy cascade reaction.

Use of a Promiscuous Glycosyltransferase from Bacillus subtilis 168 for the Enzymatic Synthesis of Novel Protopanaxatriol-Type Ginsenosides

Ginsenosides are the principal bioactive ingredients of Panax ginseng and possess diverse notable pharmacological activities. UDP-glycosyltransferase (UGT)-mediated glycosylation of the C6-OH and C20-OH of protopanaxatriol (PPT) is the prominent biological modification that contributes to the immense structural and functional diversity of PPT-type ginsenosides. In this study, the glycosylation of PPT and PPT-type ginsenosides was achieved using a promiscuous glycosyltransferase (Bs-YjiC) from Bacillus subtilis 168. PPT was selected as the probe for the in vitro glycodiversification of PPT-type ginsenosides using diverse UDP-sugars as sugar donors. Structural analysis of the newly biosynthesized products demonstrated that Bs-YjiC can transfer a glucosyl moiety to the free C3-OH, C6-OH, and C12-OH of PPT. Five PPT-type ginsenosides were biosynthesized, including ginsenoside Rh1 and four unnatural ginsenosides. The present study suggests flexible microbial UGTs play an important role in the enzymatic synthesis of novel ginsenosides.

One-pot synthesis of GDP-l-fucose by a four-enzyme cascade expressed in Lactococcus lactis

GDP-l-fucose is an l-fucose donor to synthesize fucosylated compounds such as human milk oligosaccharides or Lewis antigen. In this study, we used Lactococcus lactis subsp. cremoris NZ9000 to express 4 enzymes, ManB, ManC, Gmd, and WcaG and produced GDP-l-fucose by using one-pot synthesis method with mannose-6-phosphate as substrate and the enzymes as biocatalyst. For preparation of enzyme mixture, 4 genes (manB, manC, gmd, and wcaG) cloned from Escherichia coli were transformed into L. lactis strains using pNZ8008 and the recombinant cell lysates were obtained after cultivation. When mannose-6-phosphate was used as the substrate, the consecutive reactions with ManB, ManC, Gmd, and WcaG resulted in the successful production of GDP-l-fucose (0.13mM). When GDP-d-mannose was used as the substrate, it was entirely converted to GDP-l-fucose (0.2mM; 0.12g/L) via 2 enzymatic reactions mediated by Gmd and WcaG. This is the first report of GDP-l-fucose production by using multiple enzymes expressed in lactic acid bacteria.

Bioconversion, health benefits, and application of ginseng and red ginseng in dairy products

Ginseng and red ginseng are popular as functional foods in Asian countries such as Korea, Japan, and China. They possess various pharmacologic effects, including antioxidant, anti-inflammatory, anti-cancer, anti-obesity, and anti-viral activities. Ginsenosides are a class of pharmacologically active components in ginseng and red ginseng. Major ginsenosides are converted to minor ginsenosides, which have better bioavailability and cellular uptake, by microorganisms and enzymes. Studies have shown that ginseng and red ginseng can affect the physicochemical and sensory properties, ginsenosides content, and functional properties of dairy products. In addition, lactic acid bacteria in dairy products can convert into minor ginsenosides and ginseng and red ginseng improve functionality of products. This review will discuss the characteristics of ginseng and red ginseng, and their bioconversion, functionality, and application in dairy products.

Production of bioactive ginsenoside Rg3(S) and compound K using recombinant Lactococcus lactis

Background

Ginsenoside Rg3(S) and compound K (C-K) are pharmacologically active components of ginseng that promote human health and improve quality of life. The aim of this study was to produce Rg3(S) and C-K from ginseng extract using recombinant Lactococcus lactis.

Methods

L. lactis subsp. cremoris NZ9000 (L. lactis NZ9000), which harbors β-glucosidase genes (BglPm and BglBX10) from Paenibacillus mucilaginosus and Flavobacterium johnsoniae, respectively, was reacted with ginseng extract (protopanaxadiol-type ginsenoside mixture).

Results

Crude enzyme activity of BglBX10 values comprised 0.001 unit/mL and 0.003 unit/mL in uninduced and induced preparations, respectively. When whole cells of L. lactis harboring pNZBglBX10 were treated with ginseng extract, after permeabilization of cells by xylene, Rb1 and Rd were converted into Rg3(S) with a conversion yield of 61%. C-K was also produced by sequential reactions of the permeabilized cells harboring each pNZBgl and pNZBglBX10, resulting in a 70% maximum conversion yield.

Conclusion

This study demonstrates that the lactic acid bacteria having specific β-glucosidase activity can be used to enhance the health benefits of Panax ginseng in either fermented foods or bioconversion processes.

Comparative analysis of the expression level of recombinant ginsenoside-transforming β-glucosidase in GRAS hosts and mass production of the ginsenoside Rh2-Mix

The ginsenoside Rh₂, a pharmaceutically active component of ginseng, is known to have anticancer and antitumor effects. However, white ginseng and red ginseng have extremely low concentrations of Rh₂ or Rh₂-Mix [20(S)-Rh₂, 20(R)-Rh₂, Rk₂, and Rh₃]. To enhance the production of food-grade ginsenoside Rh₂, an edible enzymatic bioconversion technique was developed adopting GRAS host strains. A β-glucosidase (BglPm), which has ginsenoside conversion ability, was expressed in three GRAS host strains (Corynebacterium glutamicum, Saccharomyces cerevisiae and Lactococus lactis) by using a different vector system. Enzyme activity in these three GRAS hosts were 75.4%, 11.5%, and 9.3%, respectively, compared to that in the E. coli pGEX 4T-1 expression system. The highly expressed BglPm_C in C. glutamicum can effectively transform the ginsenoside Rg₃-Mix [20(S)-Rg₃, 20(R)-Rg₃, Rk₁, Rg₅] to Rh₂-Mix [20(S)-Rh₂, 20(R)-Rh₂, Rk₂, Rh₃] using a scaled-up biotransformation reaction, which was performed in a 10-L jar fermenter at pH 6.5/7.0 and 37°C for 24 h. To our knowledge, this is the first report in which 50 g of PPD-Mix (Rb₁, Rb₂, Rb₃, R_c, and Rd) as a starting substrate was converted to ginsenoside Rg₃-Mix by acid heat treatment and then 24.5-g Rh₂-Mix was obtained by enzymatic transformation of Rg₃-Mix through by BglPm_C. Utilization of this enzymatic method adopting a GRAS host could be usefully exploited in the preparation of ginsenoside Rh₂-Mix in cosmetics, functional food, and pharmaceutical industries, thereby replacing the E. coli expression system.

A literature update elucidating production of Panax ginsenosides with a special focus on strategies enriching the anti-neoplastic minor ginsenosides in ginseng preparations

Ginseng, an oriental gift to the world of healthcare and preventive medicine, is among the top ten medicinal herbs globally. The constitutive triterpene saponins, ginsenosides, or panaxosides are attributed to ginseng's miraculous efficacy towards anti-aging, rejuvenating, and immune-potentiating benefits. The major ginsenosides such as Rb1, Rb2, Rc, Rd., Re, and Rg1, formed after extensive glycosylations of the aglycone "dammaranediol," dominate the chemical profile of this genus in vivo and in vitro. Elicitations have successfully led to appreciable enhancements in the production of these major ginsenosides. However, current research on ginseng biotechnology has been focusing on the enrichment or production of the minor ginsenosides (the less glycosylated precursors of the major ginsenosides) in ginseng preparations, which are either absent or are produced in very low amounts in nature or via cell cultures. The minor ginsenosides under current scientific scrutiny include diol ginsenosides such as Rg3, Rh2, compound K, and triol ginsenosides Rg2 and Rh1, which are being touted as the next "anti-neoplastic pharmacophores," with better bioavailability and potency as compared to the major ginsenosides. This review aims at describing the strategies for ginsenoside production with special attention towards production of the minor ginsenosides from the major ginsenosides via microbial biotransformation, elicitations, and from heterologous expression systems.

Microbial transformation of ginsenoside Rb1, Re and Rg1 and its contribution to the improved anti-inflammatory activity of ginseng

Microbial transformation of ginsenosides to increase its pharmaceutical effect is gaining increasing attention in recent years. In this study, Cellulosimicrobium sp. TH-20, which was isolated from soil samples on which ginseng grown, exhibited effective ginsenoside-transforming activity. After protopanaxadiol (PPD)-type ginsenoside (Rb1) and protopanaxatriol (PPT)-type ginsenosides (Re and Rg1) were fed to C. sp. TH20, a total of 12 metabolites, including 6 new intermediate metabolites, were identified. Stepwise deglycosylation and dehydrogenation on the feeding precursors have been observed. The final products were confirmed to be rare ginsenosides Rd, GypXVII, Rg2 and PPT after 96 h transformation with 38–96% yields. The four products showed improved anti-inflammatory activities by using lipopolysaccharide (LPS)-induced murine RAW 264.7 macrophages and the xylene-induced acute inflammatory model of mouse ear edema. The results indicated that they could dramatically attenuate the production of TNF-α more effectively than the precursors. Our study would provide an example of a unique and powerful microbial cell factory for efficiently converting both PPD-type and PPT-type ginsenosides to rare natural products, which extends the drug candidates as novel anti-inflammatory remedies.

Finding and Producing Probiotic Glycosylases for the Biocatalysis of Ginsenosides: A Mini Review

Various microorganisms have been widely applied in nutraceutical industries for the processing of phytochemical conversion. Specifically, in the Asian food industry and academia, notable attention is paid to the biocatalytic process of ginsenosides (ginseng saponins) using probiotic bacteria that produce high levels of glycosyl-hydrolases. Multiple groups have conducted experiments in order to determine the best conditions to produce more active and stable enzymes, which can be applicable to produce diverse types of ginsenosides for commercial applications. In this sense, there are various reviews that cover the biofunctional effects of multiple types of ginsenosides and the pathways of ginsenoside deglycosylation. However, little work has been published on the production methods of probiotic enzymes, which is a critical component of ginsenoside processing. This review aims to investigate current preparation methods, results on the discovery of new glycosylases, the application potential of probiotic enzymes and their use for biocatalysis of ginsenosides in the nutraceutical industry.