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1.
Chinese Journal of Biotechnology ; (12): 2070-2080, 2023.
Article in Chinese | WPRIM | ID: wpr-981190

ABSTRACT

5-aminovalanoic acid (5AVA) can be used as the precursor of new plastics nylon 5 and nylon 56, and is a promising platform compound for the synthesis of polyimides. At present, the biosynthesis of 5-aminovalanoic acid generally is of low yield, complex synthesis process and high cost, which hampers large-scale industrial production. In order to achieve efficient biosynthesis of 5AVA, we developed a new pathway mediated by 2-keto-6-aminohexanoate. By combinatory expression of L-lysine α-oxidase from Scomber japonicus, α-ketoacid decarcarboxylase from Lactococcus lactis and aldehyde dehydrogenase from Escherichia coli, the synthesis of 5AVA from L-lysine in Escherichia coli was achieved. Under the initial conditions of glucose concentration of 55 g/L and lysine hydrochloride of 40 g/L, the final consumption of 158 g/L glucose and 144 g/L lysine hydrochloride, feeding batch fermentation to produce 57.52 g/L of 5AVA, and the molar yield is 0.62 mol/mol. The new 5AVA biosynthetic pathway does not require ethanol and H2O2, and achieved a higher production efficiency as compared to the previously reported Bio-Chem hybrid pathway mediated by 2-keto-6-aminohexanoate.


Subject(s)
Nylons , Lysine/metabolism , Hydrogen Peroxide/metabolism , Metabolic Engineering , Plastics/metabolism , Fermentation , Escherichia coli/metabolism , Aminocaproates/metabolism
2.
Chinese Journal of Biotechnology ; (12): 2081-2094, 2023.
Article in Chinese | WPRIM | ID: wpr-981191

ABSTRACT

Plastics are one of the most important polymers with huge global demand. However, the downsides of this polymer are that it is difficult to degrade, which causes huge pollution. The environmental-friendly bio-degradable plastics therefore could be an alternative and eventually fulfill the ever-growing demand from every aspect of the society. One of the building blocks of bio-degradable plastics is dicarboxylic acids, which have excellent biodegradability and numerous industrial applications. More importantly, dicarboxylic acid can be biologically synthesized. Herein, this review discusses the recent advance on the biosynthesis routes and metabolic engineering strategies of some of the typical dicarboxylic acids, in hope that it will help to provide inspiration to further efforts on the biosynthesis of dicarboxylic acids.


Subject(s)
Biodegradable Plastics , Dicarboxylic Acids , Polymers/metabolism , Biodegradation, Environmental , Metabolic Engineering
3.
Chinese Journal of Biotechnology ; (12): 2101-2107, 2023.
Article in Chinese | WPRIM | ID: wpr-981192

ABSTRACT

Engineering efficient enzymes or microbial cell factories should help to establish green bio-manufacturing process for chemical overproduction. The rapid advances and development in synthetic biology, systems biology and enzymatic engineering accerleate the establishing feasbile bioprocess for chemical biosynthesis, including expanding the chemical kingdom and improving the productivity. To consolidate the latest advances in chemical biosynthesis and promote green bio-manufaturing, we organized a special issue on chemical bioproduction that including review or original research papers about enzymatic biosynthesis, cell factory, one-carbon based biorefinery and feasible strategies. These papers comprehensively discussed the latest advaces, the challenges as well as the possible solutions in chemical biomanufacturing.


Subject(s)
Synthetic Biology , Carbon , Metabolic Engineering
4.
Chinese Journal of Biotechnology ; (12): 2204-2214, 2023.
Article in Chinese | WPRIM | ID: wpr-981198

ABSTRACT

Tetraacetyl phytosphingosine (TAPS) is an excellent raw material for natural skin care products. Its deacetylation leads to the production of phytosphingosine, which can be further used for synthesizing the moisturizing skin care product ceramide. For this reason, TAPS is widely used in the skin care oriented cosmetics industry. The unconventional yeast Wickerhamomyces ciferrii is the only known microorganism that can naturally secrete TAPS, and it has become the host for the industrial production of TAPS. This review firstly introduces the discovery, functions of TAPS, and the metabolic pathway for TAPS biosynthesis is further introduced. Subsequently, the strategies for increasing the TAPS yield of W. ciferrii, including haploid screening, mutagenesis breeding and metabolic engineering, are summarized. In addition, the prospects of TAPS biomanufacturing by W. ciferrii are discussed in light of the current progresses, challenges, and trends in this field. Finally, guidelines for engineering W. ciferrii cell factory using synthetic biology tools for TAPS production are also presented.


Subject(s)
Sphingosine , Ceramides , Metabolic Engineering , Synthetic Biology
5.
Chinese Journal of Biotechnology ; (12): 2231-2247, 2023.
Article in Chinese | WPRIM | ID: wpr-981200

ABSTRACT

Organic acids are organic compounds that can be synthesized using biological systems. They often contain one or more low molecular weight acidic groups, such as carboxyl group and sulphonic group. Organic acids are widely used in food, agriculture, medicine, bio-based materials industry and other fields. Yeast has unique advantages of biosafety, strong stress resistance, wide substrate spectrum, convenient genetic transformation, and mature large-scale culture technology. Therefore, it is appealing to produce organic acids by yeast. However, challenges such as low concentration, many by-products and low fermentation efficiency still exist. With the development of yeast metabolic engineering and synthetic biology technology, rapid progress has been made in this field recently. Here we summarize the progress of biosynthesis of 11 organic acids by yeast. These organic acids include bulk carboxylic acids and high-value organic acids that can be produced naturally or heterologously. Finally, future prospects in this field were proposed.


Subject(s)
Saccharomyces cerevisiae/metabolism , Organic Chemicals , Carboxylic Acids/metabolism , Metabolic Engineering , Fermentation , Acids
6.
Chinese Journal of Biotechnology ; (12): 2248-2264, 2023.
Article in Chinese | WPRIM | ID: wpr-981201

ABSTRACT

S-adenosyl-l-methionine (SAM) is ubiquitous in living organisms and plays important roles in transmethylation, transsulfuration and transamination in organisms. Due to its important physiological functions, production of SAM has attracted increasing attentions. Currently, researches on SAM production mainly focus on microbial fermentation, which is more cost-effective than that of the chemical synthesis and the enzyme catalysis, thus easier to achieve commercial production. With the rapid growth in SAM demand, interests in improving SAM production by developing SAM hyper-producing microorganisms aroused. The main strategies for improving SAM productivity of microorganisms include conventional breeding and metabolic engineering. This review summarizes the recent research progress in improving microbial SAM productivity to facilitate further improving SAM productivity. The bottlenecks in SAM biosynthesis and the solutions were also addressed.


Subject(s)
S-Adenosylmethionine/metabolism , Plant Breeding , Fermentation , Metabolic Engineering
7.
Chinese Journal of Biotechnology ; (12): 2265-2283, 2023.
Article in Chinese | WPRIM | ID: wpr-981202

ABSTRACT

Natural plant-derived diterpenoids are a class of compounds with diverse structures and functions. These compounds are widely used in pharmaceuticals, cosmetics and food additives industries because of their pharmacological properties such as anticancer, anti-inflammatory and antibacterial activities. In recent years, with the gradual discovery of functional genes in the biosynthetic pathway of plant-derived diterpenoids and the development of synthetic biotechnology, great efforts have been made to construct a variety of diterpenoid microbial cell factories through metabolic engineering and synthetic biology, resulting in gram-level production of many compounds. This article summarizes the construction of plant-derived diterpenoid microbial cell factories through synthetic biotechnology, followed by introducing the metabolic engineering strategies applied to improve plant-derived diterpenoids production, with the aim to provide a reference for the construction of high-yield plant-derived diterpenoid microbial cell factories and the industrial production of diterpenoids.


Subject(s)
Diterpenes/metabolism , Biotechnology , Metabolic Engineering , Biosynthetic Pathways/genetics , Plants/genetics , Synthetic Biology
8.
Chinese Journal of Biotechnology ; (12): 2284-2312, 2023.
Article in Chinese | WPRIM | ID: wpr-981203

ABSTRACT

Non-conventional yeasts such as Yarrowia lipolytica, Pichia pastoris, Kluyveromyces marxianus, Rhodosporidium toruloides and Hansenula polymorpha have proven to be efficient cell factories in producing a variety of natural products due to their wide substrate utilization spectrum, strong tolerance to environmental stresses and other merits. With the development of synthetic biology and gene editing technology, metabolic engineering tools and strategies for non-conventional yeasts are expanding. This review introduces the physiological characteristics, tool development and current application of several representative non-conventional yeasts, and summarizes the metabolic engineering strategies commonly used in the improvement of natural products biosynthesis. We also discuss the strengths and weaknesses of non-conventional yeasts as natural products cell factories at current stage, and prospects future research and development trends.


Subject(s)
Yeasts/genetics , Yarrowia/metabolism , Gene Editing , Metabolic Engineering
9.
Chinese Journal of Biotechnology ; (12): 2313-2333, 2023.
Article in Chinese | WPRIM | ID: wpr-981204

ABSTRACT

Rhodotorula toruloides is a non-conventional red yeast that can synthesize various carotenoids and lipids. It can utilize a variety of cost-effective raw materials, tolerate and assimilate toxic inhibitors in lignocellulosic hydrolysate. At present, it is widely investigated for the production of microbial lipids, terpenes, high-value enzymes, sugar alcohols and polyketides. Given its broad industrial application prospects, researchers have carried out multi-dimensional theoretical and technological exploration, including research on genomics, transcriptomics, proteomics and genetic operation platform. Here we review the recent progress in metabolic engineering and natural product synthesis of R. toruloides, and prospect the challenges and possible solutions in the construction of R. toruloides cell factory.


Subject(s)
Gene Editing , Metabolic Engineering , Rhodotorula/metabolism , Lipids
10.
Chinese Journal of Biotechnology ; (12): 2334-2358, 2023.
Article in Chinese | WPRIM | ID: wpr-981205

ABSTRACT

As a generally-recognized-as-safe microorganism, Saccharomyces cerevisiae is a widely studied chassis cell for the production of high-value or bulk chemicals in the field of synthetic biology. In recent years, a large number of synthesis pathways of chemicals have been established and optimized in S. cerevisiae by various metabolic engineering strategies, and the production of some chemicals have shown the potential of commercialization. As a eukaryote, S. cerevisiae has a complete inner membrane system and complex organelle compartments, and these compartments generally have higher concentrations of the precursor substrates (such as acetyl-CoA in mitochondria), or have sufficient enzymes, cofactors and energy which are required for the synthesis of some chemicals. These features may provide a more suitable physical and chemical environment for the biosynthesis of the targeted chemicals. However, the structural features of different organelles hinder the synthesis of specific chemicals. In order to ameliorate the efficiency of product biosynthesis, researchers have carried out a number of targeted modifications to the organelles grounded on an in-depth analysis of the characteristics of different organelles and the suitability of the production of target chemicals biosynthesis pathway to the organelles. In this review, the reconstruction and optimization of the biosynthesis pathways for production of chemicals by organelle mitochondria, peroxisome, golgi apparatus, endoplasmic reticulum, lipid droplets and vacuole compartmentalization in S. cerevisiae are reviewed in-depth. Current difficulties, challenges and future perspectives are highlighted.


Subject(s)
Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Golgi Apparatus/metabolism , Metabolic Engineering , Vacuoles/metabolism
11.
Chinese Journal of Biotechnology ; (12): 2359-2374, 2023.
Article in Chinese | WPRIM | ID: wpr-981206

ABSTRACT

As an essential amino acid, l-tryptophan is widely used in food, feed and medicine sectors. Nowadays, microbial l-tryptophan production suffers from low productivity and yield. Here we construct a chassis E. coli TRP3 producing 11.80 g/L l-tryptophan, which was generated by knocking out the l-tryptophan operon repressor protein (trpR) and the l-tryptophan attenuator (trpL), and introducing the feedback-resistant mutant aroGfbr. On this basis, the l-tryptophan biosynthesis pathway was divided into three modules, including the central metabolic pathway module, the shikimic acid pathway to chorismate module and the chorismate to tryptophan module. Then we used promoter engineering approach to balance the three modules and obtained an engineered E. coli TRP9. After fed-batch cultures in a 5 L fermentor, tryptophan titer reached to 36.08 g/L, with a yield of 18.55%, which reached 81.7% of the maximum theoretical yield. The tryptophan producing strain with high yield laid a good foundation for large-scale production of tryptophan.


Subject(s)
Escherichia coli/metabolism , Tryptophan , Metabolic Engineering , Bioreactors , Metabolic Networks and Pathways
12.
Chinese Journal of Biotechnology ; (12): 2375-2389, 2023.
Article in Chinese | WPRIM | ID: wpr-981207

ABSTRACT

Adipic acid is a high-value-added dicarboxylic acid which is primarily used in the production of nylon-66 for manufacturing polyurethane foam and polyester resins. At present, the biosynthesis of adipic acid is hampered by its low production efficiency. By introducing the key enzymes of adipic acid reverse degradation pathway into a succinic acid overproducing strain Escherichia coli FMME N-2, an engineered E. coli JL00 capable of producing 0.34 g/L adipic acid was constructed. Subsequently, the expression level of the rate-limiting enzyme was optimized and the adipic acid titer in shake-flask fermentation increased to 0.87 g/L. Moreover, the supply of precursors was balanced by a combinatorial strategy consisting of deletion of sucD, over-expression of acs, and mutation of lpd, and the adipic acid titer of the resulting E. coli JL12 increased to 1.51 g/L. Finally, the fermentation process was optimized in a 5 L fermenter. After 72 h fed-batch fermentation, adipic acid titer reached 22.3 g/L with a yield of 0.25 g/g and a productivity of 0.31 g/(L·h). This work may serve as a technical reference for the biosynthesis of various dicarboxylic acids.


Subject(s)
Escherichia coli/metabolism , Metabolic Engineering , Bioreactors , Fermentation , Adipates/metabolism
13.
Chinese Journal of Biotechnology ; (12): 2390-2409, 2023.
Article in Chinese | WPRIM | ID: wpr-981208

ABSTRACT

The use of light energy to drive carbon dioxide (CO2) reduction for production of chemicals is of great significance for relieving environmental pressure and solving energy crisis. Photocapture, photoelectricity conversion and CO2 fixation are the key factors affecting the efficiency of photosynthesis, and thus also affect the efficiency of CO2 utilization. To solve the above problems, this review systematically summarizes the construction, optimization and application of light-driven hybrid system from the perspective of combining biochemistry and metabolic engineering. We introduce the latest research progress of light-driven CO2 reduction for biosynthesis of chemicals from three aspects: enzyme hybrid system, biological hybrid system and application of these hybrid system. In the aspect of enzyme hybrid system, many strategies were adopted such as improving enzyme catalytic activity and enhancing enzyme stability. In the aspect of biological hybrid system, many methods were used including enhancing biological light harvesting capacity, optimizing reducing power supply and improving energy regeneration. In terms of the applications, hybrid systems have been used in the production of one-carbon compounds, biofuels and biofoods. Finally, the future development direction of artificial photosynthetic system is prospected from the aspects of nanomaterials (including organic and inorganic materials) and biocatalysts (including enzymes and microorganisms).


Subject(s)
Carbon Dioxide/metabolism , Photosynthesis , Metabolic Engineering
14.
Chinese Journal of Biotechnology ; (12): 2410-2429, 2023.
Article in Chinese | WPRIM | ID: wpr-981209

ABSTRACT

The current linear economy model relies on fossil energy and increases CO2 emissions, which contributes to global warming and environmental pollution. Therefore, there is an urgent need to develop and deploy technologies for carbon capture and utilization to establish a circular economy. The use of acetogens for C1-gas (CO and CO2) conversion is a promising technology due to high metabolic flexibility, product selectivity, and diversity of the products including chemicals and fuels. This review focuses on the physiological and metabolic mechanisms, genetic and metabolic engineering modifications, fermentation process optimization, and carbon atom economy in the process of C1-gas conversion by acetogens, with the aim to facilitate the industrial scale-up and carbon negative production through acetogen gas fermentation.


Subject(s)
Fermentation , Gases/metabolism , Carbon Dioxide/metabolism , Metabolic Engineering , Carbon/metabolism
15.
Chinese Journal of Biotechnology ; (12): 2430-2448, 2023.
Article in Chinese | WPRIM | ID: wpr-981210

ABSTRACT

Methanol has become an attractive substrate for the biomanufacturing industry due to its abundant supply and low cost. The biotransformation of methanol to value-added chemicals using microbial cell factories has the advantages of green process, mild conditions and diversified products. These advantages may expand the product chain based on methanol and alleviate the current problem of biomanufacturing, which is competing with people for food. Elucidating the pathways involving methanol oxidation, formaldehyde assimilation and dissimilation in different natural methylotrophs is essential for subsequent genetic engineering modification, and is more conducive to the construction of novel non-natural methylotrophs. This review discusses the current status of research on methanol metabolic pathways in methylotrophs, and presents recent advances and challenges in natural and synthetic methylotrophs and their applications in methanol bioconversion.


Subject(s)
Humans , Methanol/metabolism , Metabolic Engineering , Metabolic Networks and Pathways , Biotransformation
16.
Chinese Journal of Biotechnology ; (12): 2485-2501, 2023.
Article in Chinese | WPRIM | ID: wpr-981213

ABSTRACT

Amino acids are the basic building blocks of protein that are very important to the nutrition and health of humans and animals, and widely used in feed, food, medicine and daily chemicals. At present, amino acids are mainly produced from renewable raw materials by microbial fermentation, forming one of the important pillar industries of biomanufacturing in China. Amino acid-producing strains are mostly developed through random mutagenesis- and metabolic engineering-enabled strain breeding combined with strain screening. One of the key limitations to further improvement of production level is the lack of efficient, rapid, and accurate strain screening methods. Therefore, the development of high-throughput screening methods for amino acid strains is very important for the mining of key functional elements and the creation and screening of hyper-producing strains. This paper reviews the design of amino acid biosensors and their applications in the high-throughput evolution and screening of functional elements and hyper-producing strains, and the dynamic regulation of metabolic pathways. The challenges of existing amino acid biosensors and strategies for biosensor optimization are discussed. Finally, the importance of developing biosensors for amino acid derivatives is prospected.


Subject(s)
Animals , Humans , Amino Acids , Biosensing Techniques , Metabolic Engineering , High-Throughput Screening Assays , China
17.
Chinese Journal of Biotechnology ; (12): 993-1008, 2023.
Article in Chinese | WPRIM | ID: wpr-970418

ABSTRACT

The development of synthetic biology has greatly promoted the construction of microbial cell factories, providing an important strategy for green and efficient chemical production. However, the bottleneck of poor tolerance to harsh industrial environments has become the key factor hampering the productivity of microbial cells. Adaptive evolution is an important method to domesticate microorganisms for a certain period by applying targeted selection pressure to obtain desired phenotypic or physiological properties that are adapted to a specific environment. Recently, with the development of technologies such as microfluidics, biosensors, and omics analysis, adaptive evolution has laid the foundation for efficient productivity of microbial cell factories. Herein, we discuss the key technologies of adaptive evolution and their important applications in improvement of environmental tolerance and production efficiency of microbial cell factories. Moreover, we looked forward to the prospects of adaptive evolution to realize industrial production by microbial cell factories.


Subject(s)
Metabolic Engineering , Industrial Microbiology/methods , Synthetic Biology , Environment , Industry
18.
Chinese Journal of Biotechnology ; (12): 3253-3272, 2023.
Article in Chinese | WPRIM | ID: wpr-1007956

ABSTRACT

As a branched chain amino acid, L-valine is widely used in the medicine and feed sectors. In this study, a microbial cell factory for efficient production of L-valine was constructed by combining various metabolic engineering strategies. First, precursor supply for L-valine biosynthesis was enhanced by strengthening the glycolysis pathway and weakening the metabolic pathway of by-products. Subsequently, the key enzyme in the L-valine synthesis pathway, acetylhydroxylate synthase, was engineered by site-directed mutation to relieve the feedback inhibition of the engineered strain. Moreover, promoter engineering was used to optimize the gene expression level of key enzymes in L-valine biosynthetic pathway. Furthermore, cofactor engineering was adopted to change the cofactor preference of acetohydroxyacid isomeroreductase and branched-chain amino acid aminotransferase from NADPH to NADH. The engineered strain C. glutamicum K020 showed a significant increase in L-valine titer, yield and productivity in 5 L fed-batch bioreactor, up to 110 g/L, 0.51 g/g and 2.29 g/(L‧h), respectively.


Subject(s)
Valine , Corynebacterium glutamicum/genetics , Metabolic Engineering , Amino Acids, Branched-Chain , Bioreactors
19.
Chinese Journal of Biotechnology ; (12): 3273-3289, 2023.
Article in Chinese | WPRIM | ID: wpr-1007957

ABSTRACT

L-glutamic acid is the world's largest bulk amino acid product that is widely used in the food, pharmaceutical and chemical industries. Using Corynebacterium glutamicum G01 as the starting strain, the fermentation by-product alanine content was firstly reduced by knocking out the gene encoding alanine aminotransferase (alaT), a major by-product related to alanine synthesis. Secondly, since the α-ketoglutarate node carbon flow plays an important role in glutamate synthesis, the ribosome-binding site (RBS) sequence optimization was used to reduce the activity of α-ketoglutarate dehydrogenase and enhance the glutamate anabolic flow. The endogenous conversion of α-ketoglutarate to glutamate was also enhanced by screening different glutamate dehydrogenase. Subsequently, the glutamate transporter was rationally desgined to improve the glutamate efflux capacity. Finally, the fermentation conditions of the strain constructed using the above strategy were optimized in 5 L fermenters by a gradient temperature increase combined with a batch replenishment strategy. The glutamic acid production reached (135.33±4.68) g/L, which was 41.2% higher than that of the original strain (96.53±2.32) g/L. The yield was 55.8%, which was 11.6% higher than that of the original strain (44.2%). The combined strategy improved the titer and the yield of glutamic acid, which provides a reference for the metabolic modification of glutamic acid producing strains.


Subject(s)
Glutamic Acid , Corynebacterium glutamicum/genetics , Ketoglutaric Acids , Metabolic Engineering , Alanine
20.
Chinese Journal of Biotechnology ; (12): 3290-3301, 2023.
Article in Chinese | WPRIM | ID: wpr-1007958

ABSTRACT

Salicylate 2-O-β-d-glucoside (SAG) is a derivative of salicylate in plants. Recent reports showed that SAG could be considered as a potential anti-inflammatory substance due to its anti-inflammatory and analgesic effects, and less irritation compared with salicylic acid and aspirin. The biological method uses renewable resources to produce salicylic acid compounds, which is more environmentally friendly than traditional industry methods. In this study, Escherichia coli Tyr002 was used as the starting strain, and a salicylic acid producing strain of E. coli was constructed by introducing the isochorismate pyruvate lyase gene pchB from Pseudomonas aeruginosa. By regulating the expression of the key genes in the downstream aromatic amino acid metabolic pathways, the titer of salicylic acid reached 1.05 g/L in shake flask fermentation. Subsequently, an exogenous salicylic acid glycosyltransferase was introduced into the salicylic acid producing strain to glycosylate the salicylic acid. The newly engineered strain produced 5.7 g/L SAG in shake flask fermentation. In the subsequent batch fed fermentation in a 5 L fermentation tank, the titer of SAG reached 36.5 g/L, which is the highest titer reported to date. This work provides a new route for biosynthesis of salicylate and its derivatives.


Subject(s)
Escherichia coli/genetics , Glucosides , Metabolic Engineering , Salicylic Acid , Pyruvic Acid
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