Biodegradation of Typical Plastics: From Microbial Diversity to Metabolic Mechanisms

Plastic production has increased dramatically, leading to accumulated plastic waste in the ocean. Marine plastics can be broken down into microplastics (<5 mm) by sunlight, machinery, and pressure. The accumulation of microplastics in organisms and the release of plastic additives can adversely affect the health of marine organisms. Biodegradation is one way to address plastic pollution in an environmentally friendly manner. Marine microorganisms can be more adapted to fluctuating environmental conditions such as salinity, temperature, pH, and pressure compared with terrestrial microorganisms, providing new opportunities to address plastic pollution. Pseudomonadota (Proteobacteria), Bacteroidota (Bacteroidetes), Bacillota (Firmicutes), and Cyanobacteria were frequently found on plastic biofilms and may degrade plastics. Currently, diverse plastic-degrading bacteria are being isolated from marine environments such as offshore and deep oceanic waters, especially Pseudomonas spp. Bacillus spp. Alcanivoras spp. and Actinomycetes. Some marine fungi and algae have also been revealed as plastic degraders. In this review, we focused on the advances in plastic biodegradation by marine microorganisms and their enzymes (esterase, cutinase, laccase, etc.) involved in the process of biodegradation of polyethylene terephthalate (PET), polystyrene (PS), polyethylene (PE), polyvinyl chloride (PVC), and polypropylene (PP) and highlighted the need to study plastic biodegradation in the deep sea.

Recent Advances on Key Enzymes of Microbial Origin in the Lycopene Biosynthesis Pathway

Lycopene is a common carotenoid found mainly in ripe red fruits and vegetables that is widely used in the food industry due to its characteristic color and health benefits. Microbial synthesis of lycopene is gradually replacing the traditional methods of plant extraction and chemical synthesis as a more economical and productive manufacturing strategy. The biosynthesis of lycopene is a typical multienzyme cascade reaction, and it is important to understand the characteristics of each key enzyme involved and how they are regulated. In this paper, the catalytic characteristics of the key enzymes involved in the lycopene biosynthesis pathway and related studies are first discussed in detail. Then, the strategies applied to the key enzymes of lycopene synthesis, including fusion proteins, enzyme screening, combinatorial engineering, CRISPR/Cas9-based gene editing, DNA assembly, and scaffolding technologies are purposefully illustrated and compared in terms of both traditional and emerging multienzyme regulatory strategies. Finally, future developments and regulatory options for multienzyme synthesis of lycopene and similar secondary metabolites are also discussed.

[Phenylpropanoid pathway in plants and its role in response to heavy metal stress: a review]

Phenylpropanoid metabolic pathway is one of the most important secondary metabolic pathways in plants. It directly or indirectly plays an antioxidant role in plant resistance to heavy metal stress, and can improve the absorption and stress tolerance of plants to heavy metal ions. In this paper, the core reactions and key enzymes of the phenylpropanoid metabolic pathway were summarized, and the biosynthetic processes of key metabolites such as lignin, flavonoids and proanthocyanidins and relevant mechanisms were analyzed. Based on this, the mechanisms of key products of phenylpropanoid metabolic pathway in response to heavy metal stress were discussed. The perspectives on the involvement of phenylpropanoid metabolism in plant defense against heavy metal stress provides a theoretical basis for improving the phytoremediation efficiency of heavy metal polluted environment.

Characteristic flavor metabolic network of fish sauce microbiota with different fermentation processes based on metagenomics

This article purposed to discuss the connection between microbiota and characteristic flavor of different fish sauces (Natural fermentation (WQ), koji outdoor fermentation (YQ), heat preservation with enzyme (BWE), and heat preservation with koji (BWQ)) at the early (3 months) and late stage (7 months). A total of 117 flavor compounds were determined according to SPME-GC-MS analysis. O2PLS-DA and VIP values were used to reveal 15 and 28 flavor markers of different fish sauces at 3 and 7 M of fermentation. Further, the possible flavor formation pathways were analyzed using metagenomic sequencing, and the key microbes associated with flavor formation were identified at the genetic level. The top 10 genera related to flavor generation, such as Lactobacillus, Staphylococcus, Enterobacter, etc., appeared to play a prominent part in the flavor formation of fish sauce. The difference was that only BWQ and BWE groups could produce ethyl-alcohol through amino acid metabolism, while YQ, BWE and BWQ groups could generate phenylacetaldehyde through the transformation of Phe by α-ketoacid decarboxylase and aromatic amino acid transferase. Our research contributes to clarifying the various metabolic roles of microorganisms in the flavor generation of fish sauce.

Arbuscular mycorrhizal fungi: Effects on secondary metabolite accumulation of traditional Chinese medicines

Traditional Chinese medicine (TCM) has played a pivotal role in maintaining the health of people, and the intrinsic quality of TCM is directly related to the clinical efficacy. The medicinal ingredients of TCM are derived from the secondary metabolites of plant metabolism and are also the result of the coordination of various physiological activities in plants. Arbuscular mycorrhizal fungi (AMF) are among the most ubiquitous plant mutualists that enhance the growth and yield of plants by facilitating the uptake of nutrients and water. Symbiosis of AMF with higher plants promotes growth and helps in the accumulation of secondary metabolites. However, there is still no systematic analysis and summation of their roles in the application of TCM, biosynthesis and accumulation of active substances of herbs, as well as the mechanisms. AMF directly or indirectly affect the accumulation of secondary metabolites of TCM, which is the focus of this review. First, in this review, the effects of AMF symbiosis on the content of different secondary metabolites in TCM, such as phenolic acids, flavonoids, alkaloids and terpenoids, are summarized. Moreover, the mechanism of AMF regulating the synthesis of secondary metabolites was also considered, in combination with the establishment of mycorrhizal symbionts, response mechanisms of plant hormones, nutritional elements and expression of key enzyme their activities. Finally, combined with the current application prospects for AMF in TCM, future in-depth research is planned, thus providing a reference for improving the quality of TCM. In this manuscript, we review the research status of AMF in promoting the accumulation of secondary metabolites in TCM to provide new ideas and methods for improving the quality of TCM.

[Identification of key enzyme genes involved in biosynthesis pathways of lignan and lignin in Eucommia ulmoides based on transcriptome assembly]

Lignan is the main medicinal component of Eucommia ulmoides, and lignin is involved in the defense of plants against diseases and insect pests.They are synthesized from coniferyl alcohol with the help of dirigent(DIR) and peroxidase(POD), respectively.In this study, transcriptome assembly of stems and leaves of E.ulmoides was performed, yielding 112 578 unigenes.Among them, 70 459 were annotated in seven databases.A total of 59 unigenes encodes 11 key enzymes in the biosynthesis pathways of lignin and lignin, of which 11 encode POD and 8 encode DIR.A total of 13 unigenes encoding transcription factors are involved in phenylpropanoid metabolism. Compared with leaves of E.ulmoides, 7 575 unigenes were more highly expressed in stems, of which 462 were involved in phenylpropanoid biosynthesis.Our results extend the public transcriptome dataset of E.ulmoides, which provide valuable information for the analysis of biosynthesis pathways of lignan and lignin in E.ulmoides and lay a foundation for further study on the functions and regulation mechanism of key enzymes in lignan and lignin biosynthesis pathways.

Identification of the Key Enzymes in WL Gum Biosynthesis and Critical Composition in Viscosity Control

As an important microbial exopolysaccharide, the sphingan WL gum could be widely used in petroleum, food, and many other fields. However, its lower production is still limiting its wider application. Therefore, to gain insights into the bottlenecks of WL gum production by identifying the key enzymes in the WL gum biosynthesis pathway, more than 20 genes were over-expressed in Sphingomonas sp. WG and their effects on WL gum production and structure were investigated. Compared to the control strain, the WL gum production of welB over-expression strain was increased by 19.0 and 21.0% at 36 and 84 h, respectively. The WL gum production of both atrB and atrD over-expression strains reached 47 g/L, which was approximately 34.5% higher than that of the control strain at 36 h. Therefore, WelB, AtrB, and AtrD may be the key enzymes in WL production. Interestingly, the broth viscosity of most over-expression strains decreased, especially the welJ over-expression strain whose viscosity decreased by 99.3% at 84 h. Polysaccharides' structural features were investigated to find the critical components in viscosity control. The uronic acid content and total sugar content was affected by only a few genes, therefore, uronic acid and total sugar content may be not the key composition. In comparison, the acetyl degrees were enhanced by over-expression of most genes, which meant that acetyl content may be the critical factor and negatively correlated with the apparent viscosity of WL gum. This work provides useful information on the understanding of the bottlenecks of WL gum biosynthesis and will be helpful for the construction of high WL gum-yielding strains and rheological property controlling in different industries.

[Screening and identification of key enzyme genes for steroidal saponin biosynthesis in Dioscorea zingiberensis under low phosphorus stress]

To investigate the responses of key enzymes involved in steroidal saponin biosynthesis of Dioscorea zingiberensis to low phosphorus stress, we designed three treatments of severe phosphorus stress, moderate phosphorus stress, and normal phosphorus level. The D. zingiberensis plants were collected at the early, middle, and late stages of treatment. The content of total steroidal saponins in different tissues of D. zingiberensis was determined by spectrophotometry for the identification of the critical stage in response to low phosphorus stress. BGI 500 sequencing platform was employed to obtain the transcript information of D. zingiberensis samples at the critical stage of low phosphorus stress, and then a transcriptome library was constructed. The correlation between the expression of genes involved in steroidal saponin biosynthesis and the content of total steroidal saponins was analyzed for the screening of the key enzyme genes in response to low phosphorus stress. Further, the expression patterns of these genes were analyzed by real-time fluorescence PCR(qRT-PCR). The content of total steroidal saponins in D. zingiberensis had obvious tissue specificity under low phosphorus stress, and the early stage of stress was particularly important for D. zingiberensis to respond to low phosphorus stress. A total of 101 593 unigenes were obtained by transcriptome sequencing, of which 77.35% were annotated in NT, NR, SwissProt, KOG, GO, and KEGG. A total of 256 transcripts of known key enzyme genes in the biosynthetic pathway of steroidal saponins were identified. The expression levels of 69 transcripts encoding 18 catalytic enzymes were significantly correlated with the content of total steroidal saponins. The qRT-PCR results showed that several key enzyme genes presented different expression patterns in four tissues under low phosphorus stress. The results indicated that the content of total steroidal saponins and the expression of key enzyme genes regulating steroidal saponin biosynthesis in D. zingensis changed under low phosphorus stress. This study provides the biological information for elucidating the molecular mechanism of steroidal saponin biosynthesis in D. zingensis exposed to low phosphorus stress.

Influence of Nutrient (NPK) Factors on Growth, and Pharmacodynamic Component Biosynthesis of Atractylodes chinensis: An Insight on Acetyl-CoA Carboxylase (ACC), 3-Hydroxy-3-Methylglutaryl-CoA Reductase (HMGR), and Farnesyl Pyrophosphate Synthase (FPPS) Signaling Responses

In the planting of crops, especially medicinal plants, formula fertilization is important for improving the utilization rate of elements, soil quality, crop yield, and quality. Therefore, it is important to study targeted fertilizer application schemes for sustainable agricultural development and environmental protection. In this study, an L₉(3⁴) orthogonal design was used to conduct a field experiment to study the effects of NPK combined application on the growth and pharmacodynamic component biosynthesis of Atractylodes chinensis (DC.) Koidz. Results showed that after applying a base fertilizer at the seedling stage (late May), topdressing at the vegetative stage (late June) and fruit stage (late August) was beneficial to the growth and development of A. chinensis. The high concentrations of phosphorus were conducive to the accumulation of yield and effective components, and the best harvest time was after late October. Principal component analysis (PCA) showed that the comprehensive score of T6 treatment was the highest, indicating that the optimal fertilization scheme for the high yield and high quality of A. chinensis was (N₂P₃K₁): N 180, P₂O₅ 225, and K₂O 105 kg⋅ha^-1. A signaling response analysis showed that during the growth and development of A. chinensis, the T6 fertilization scheme had clear effects on the activity and gene expression of the key enzymes acetyl-CoA carboxylase (ACC) and farnesyl pyrophosphate synthase (FPPS). Under the T4 [(N₂P₁K₂): N 180, P₂O₅ 75, and K₂O 210 kg⋅ha^-1] fertilization scheme, the activity and gene expression of the key enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) were higher. Moreover, ACC was closely related to the synthesis of the polyacetylene component atractylodin, and FPPS played an important regulatory role in the synthesis of sesquiterpene components atractylenolide II, β-eudesmol, and atractylon. In summary, the high phosphorus fertilization scheme T6 could notably increase the yield of A. chinensis, and promote the accumulation of polyacetylene and sesquiterpene volatile oils by increasing the expression of ACC and FPPS. Therefore, we postulate that the precise application of nutrients (NPK) plays a vital role in the yield formation and quality regulation of A. chinensis.

Glycometabolic rearrangements-aerobic glycolysis in pancreatic ductal adenocarcinoma (PDAC): roles, regulatory networks, and therapeutic potential

INTRODUCTION

Glycometabolic rearrangements (aerobic glycolysis) is a hallmark of pancreatic ductal adenocarcinoma (PDAC) and contributes to tumorigenesis and progression through numerous mechanisms. The targeting of aerobic glycolysis is recognized as a potential therapeutic strategy which offers the possibility of improving treatment outcomes for PDAC patients.

AREAS COVERED

In this review, the role of aerobic glycolysis and its regulatory networks in PDAC are discussed. The targeting of aerobic glycolysis in PDAC is examined, and its therapeutic potential is evaluated. The relevant literature published from 2001 to 2021 was searched in databases including PubMed, Scopus, and Embase.

EXPERT OPINION

Regulatory networks of aerobic glycolysis in PDAC are based on key factors such as c-Myc, hypoxia-inducible factor 1α, the mammalian target of rapamycin pathway, and non-coding RNAs. Experimental evidence suggests that modulators or inhibitors of aerobic glycolysis promote therapeutic effects in preclinical tumor models. Nevertheless, successful clinical translation of drugs that target aerobic glycolysis in PDAC is an obstacle. Moreover, it is necessary to identify the potential targets for future interventions from regulatory networks to design efficacious and safer agents.

Study of the properties of carotenoids and key carotenoid biosynthesis genes from Deinococcus xibeiensis R13

To investigate the properties of carotenoids from the extremophile Deinococcus xibeiensis R13, the factors affecting the stability of carotenoids extracted from D. xibeiensis R13, including temperature, illumination, pH, redox chemicals, metal ions, and food additives, were investigated. The results showed that low temperature, neutral pH, reducing agents, Mn²⁺ , and food additives (xylose and glucose) can effectively improve the stability of Deinococcus carotenoids. The carotenoids of D. xibeiensis R13 exhibited strong antioxidant activity, with the scavenging rate of hydroxyl radicals reaching 71.64%, which was higher than the scavenging efficiency for 1,1-diphenyl-2-picrylhydrazyl free radicals and 2,2'-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) free radicals (44.55 and 27.65%, respectively). In addition, the total antioxidant capacity reached 0.60 U/ml, which was 2.61-fold that of carotenoids from the model strain Deinococcus radiodurans R1. Finally, we predicted the gene clusters encoding carotenoid biosynthesis pathways in the genome of R13 and identified putative homologous genes. The key enzyme genes (crtE, crtB, crtI, crtLm, cruF, crtD, and crtO) in carotenoid synthesis of D. xibeiensis R13 were cloned to construct the multigene coexpression plasmids pET-EBI and pRSF-LmFDO. The carotenoid biosynthesis pathway was heterologously introduced into engineered Escherichia coli EBILmFDO, which exhibited a higher yield (7.14 mg/L) than the original strain. These analysis results can help us to better understand the metabolic synthesis of carotenoids in extremophiles.

[Germacrene-derived sesquiterpene lactones:opportunities and challenges for biosynthesis]

Sesquiterpene lactones are a kind of widely distributed natural organic compounds with anti-tumor, anti-malarial and other significant biological activities. Based on their carbocylic skeletons, sesquiterpene lactones are classified into germacranolide, guaia-nolide, xanthanolide, pseudo-guaianolide, elemonolide and eudesmanolide, etc. In recent years, with the development of various omics and synthetic biology technologies, the biosynthetic pathways of sesquiterpene lactone compounds of different structural types have gradually been resolved. Among them, the researches on germacrene-derived sesquiterpene lactones are relatively more than others. Therefore, this article focused on the germacrene-derived sesquiterpene lactone biosynthesis pathways and their key enzyme genes, which can lay the foundation for in-depth analysis of sesquiterpene lactone biosynthetic pathways, functional gene mining and heterologous synthesis of active ingredients.

[Pathway design and key enzyme analysis of diosgenin biosynthesis]

As a naturally occurring steroid sapogenin, diosgenin acts as the precursor of hundreds of steroid medicines, and thereby has important medicinal value. Currently, industrial production of diosgenin relies primarily on chemical extraction from plant materials. Clearly, this strategy shows drawbacks of excessive reliance on plant materials and farmland as well as environment pollution. Due to development of metabolic engineering and synthetic biology, bio-production of diosgenin has garnered plenty of attention. Although the biosynthetic pathways of diosgenin have not been completely identified, in this review, we outline the identified biosynthetic pathways and key enzymes. In particular, we suggest heterologous biosynthesis of diosgenin in Saccharomyces cerevisiae. Overall, this review aims to provide valuable insights for future complete biosynthesis of diosgenin.

Research Progress of the Biosynthesis of Natural Bio-Antibacterial Agent Pulcherriminic Acid in Bacillus

Pulcherriminic acid is a cyclic dipeptide found mainly in Bacillus and yeast. Due to the ability of pulcherriminic acid to chelate Fe3+ to produce reddish brown pulcherrimin, microorganisms capable of synthesizing pulcherriminic acid compete with other microorganisms for environmental iron ions to achieve bacteriostatic effects. Therefore, studying the biosynthetic pathway and their enzymatic catalysis, gene regulation in the process of synthesis of pulcherriminic acid in Bacillus can facilitate the industrial production, and promote the wide application in food, agriculture and medicine industries. After initially discussing, this review summarizes current research on the synthesis of pulcherriminic acid by Bacillus, which includes the crystallization of key enzymes, molecular catalytic mechanisms, regulation of synthetic pathways, and methods to improve efficiency in synthesizing pulcherriminic acid and its precursors. Finally, possible applications of pulcherriminic acid in the fermented food, such as Chinese Baijiu, applying combinatorial biosynthesis will be summarized.

Bioeffect of static magnetic field on photosynthetic bacteria: Evaluation of bioresources production and wastewater treatment efficiency

Photosynthetic bacteria (PSB) technology is a promising method for biomass, protein, pigments, and other value-added substances generation from wastewater. However, the above bioresources production efficiency is relatively low. In this work, a static magnetic field (SMF) was used to promote bioresources production. Results showed that SMF had positive effects on value-added substances production. With 0.35 Tesla (T) SMF, the PSB biomass, protein, carotenoids, and bacteriochlorophyll concentration were promoted by 31.1%, 22.6%, 56.7%, and 73.1% compared with the control group, respectively. Biomass yield finally reached 0.58 g biomass/g COD removal, which was promoted by 37.1%. The doubling time was shortened by 37.9% in 0.35 T group, showing that SMF can promote cell growth. With 0.35 T SMF, the intracellular NADH dehydrogenase and ATP synthase activities concentration increased by 23.4% and 29.1%, respectively, thus increased the ATP content by 38.0%. Succinic dehydrogenase activity concentration greatly increased by 609.0% at 48 hr, which potentially accelerated the tricarboxylic acid cycle and COD degradation as well as enhanced biomass production. PRACTITIONER POINTS: SMF promoted PSB bioresource production during wastewater treatment processing. Biomass, protein, carotenoids, and Bchl concentration were promoted by 31.1%, 22.6%, 56.7%, and 73.1%, respectively. PSB yield of 0.35 T group was promoted by 37.1% compared with the control group. SDH concentration of 0.35 T was promoted by 609.0% compared with the control group. Increased NADH and ATP synthase activity concentration by SMF enhanced energy metabolism.

Structure and Location Studies on Key Enzymes in Saponins Biosynthesis of Panax notoginseng

Panax notoginseng is one of the most widely used traditional herbs for the treatment of various diseases, in which saponins were the main active components. At present, the research of P. notoginseng mainly focused on the discovery of new compounds and pharmacology. However, there were few studies on the molecular mechanism of the synthesis of secondary metabolites of P. notoginseng. In our study, four coding sequences (CDS) encoding the key enzymes involved in saponin biosynthesis were cloned, namely farnesyl diphosphate synthase (FPS), squalene synthase (SS), squalene epoxidase (SE), and dammarenediol-II synthase (DS), which contained open reading frame (ORF) of 1029 bp, 1248 bp, 1614 bp, and 2310 bp, and coded 342, 415, 537, and 769 amino acids, respectively. At the same time, their domains, secondary structures, three-dimensional structures, and phylogenetics trees were analyzed by kinds of bioinformatics tools. Their phylogenetics relationships were also analyzed. In addition, GFP (Green fluorescent protein) fusion genes were constructed by the plasmid transformation system to determine the subcellular localization. The results of subcellular localization showed that FPS, SE, and DS were mainly located in cytomembrane and its surrounding, while SS was located both in cytoplasm and cytomembrane. Our findings provided data demonstrating the expression patterns of genes involved in saponin biosynthesis and would facilitate efforts to further elucidate the biosynthesis of the bioactive components in P. notoginseng.

Physicochemical and Biological Effects on Activated Sludge Performance and Activity Recovery of Damaged Sludge by Exposure to CeO2 Nanoparticles in Sequencing Batch Reactors

Recently, the growing release of CeO₂ nanoparticles (CeO₂ NPs) into sewage systems has attracted great concern. Several studies have extensively explored CeO₂ NPs' potential adverse impacts on wastewater treatment plants; however, the impaired activated sludge recovery potentials have seldom been addressed to date. To explore the physicochemical and biological effects on the activated sludge performance and activity recovery of damaged sludge by exposure to CeO₂ NPs in sequencing batch reactors (SBRs), four reactors and multiple indicators including water quality, key enzymes, microbial metabolites, the microbial community structure and toxicity were used. Results showed that 10-week exposure to higher CeO₂ NP concentration (1, 10 mg/L) resulted in a sharp decrease in nitrogen and phosphorus removal efficiencies, which were consistent with the tendencies of key enzymes. Meanwhile, CeO₂ NPs at concentrations of 0.1, 1, and 10 mg/L decreased the secretion of tightly bound extracellular polymeric substances to 0.13%, 3.14%, and 28.60%, respectively, compared to the control. In addition, two-week recovery period assays revealed that the functional bacteria Proteobacteria, Nitrospirae and Planctomycetes recovered slightly at the phyla level, as analyzed through high-throughput sequencing, which was consistent with the small amount of improvement of the effluent performance of the system. This reflected the small possibility of the activity recovery of damaged sludge.

Progress on the Studies of the Key Enzymes of Ginsenoside Biosynthesis

As the main bioactive constituents of Panax species, ginsenosides possess a wide range of notable medicinal effects such as anti-cancer, anti-oxidative, antiaging, anti-inflammatory, anti-apoptotic and neuroprotective activities. However, the increasing medical demand for ginsenosides cannot be met due to the limited resource of Panax species and the low contents of ginsenosides. In recent years, biotechnological approaches have been utilized to increase the production of ginsenosides by regulating the key enzymes of ginsenoside biosynthesis, while synthetic biology strategies have been adopted to produce ginsenosides by introducing these genes into yeast. This review summarizes the latest research progress on cloning and functional characterization of key genes dedicated to the production of ginsenosides, which not only lays the foundation for their application in plant engineering, but also provides the building blocks for the production of ginsenosides by synthetic biology.

Increased expression of glycolytic enzymes in prostate cancer tissues and association with Gleason scores

OBJECTIVE

Recent studies have shown that understanding the differences between Gleason 3+4 and Gleason 4+3 in PCa patients may improve their treatment. This study aimed to evaluate the different expression levels of glycolytic proteins for Gleason score of 4+3 and 3+4.

METHODS

A total of 90 PCa patients, including 38 cases with a Gleason score of 7, were included in this study. The expression of glycolytic proteins in both prostate cancer and normal prostate tissues, in GGG2 and GGG3 as well were assessed by immunohistochemical staining.

RESULTS

Compared with GGG3, the GGG2 cases displayed significantly lower expression of all proteins (P < 0.05). The correlation among all enzymes showed that the key glycolytic enzyme, HK2, was significantly positively related to another key enzyme, PKM2 (r = 0.550, P < 0.01), and the expression of PFKFB4 was correlated with the expression of HK2 (r = 0.236, P < 0.05) and PKM2 (r = 0.392, P < 0.01). Additionally, neither GLUT1 nor PFKFB3 was correlated with PFKFB4, HK2 or PKM2. Further analysis showed that HK2 (r = 0.297, P < 0.01) and PKM2 (r = 0.431, P < 0.01) were significantly positively related to the Gleason score in PCa tissues.

CONCLUSIONS

Glycolytic proteins expression levels were upregulated in PCa tissues. Furthermore, GGG3 exhibits a higher level of glycolysis compared with GGG2 in PCa tissues. Additionally, the key glycolytic enzymes, HK2 and PKM2, are overexpressed simultaneously in PCa and significantly correlate with PCa progression as represented by the GS.

Plant non-starch polysaccharides that inhibit key enzymes linked to type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM), a metabolic disease becoming ever more common, is the result of disturbed glyco- and lipid metabolism. On the basis of their inhibitory effects against several key enzymes linked to T2DM, synthetic antidiabetic agents have been developed and used for diabetic therapy, some with adverse side effects. Fortunately, many plant non-starch polysaccharides (NSPs) have been shown to possess inhibitory effects on the same T2DM-related enzymes. Through a simple literature search we found that α-amylase, α-glucosidase, lipase, and dipeptidyl-peptidase IV are the enzymes most often reported in the context of T2DM. In this short review we discuss published evidence for inhibition of these enzymes and the implications for treating T2DM.

Solanesol Biosynthesis in Plants

Solanesol is a non-cyclic terpene alcohol composed of nine isoprene units that mainly accumulates in solanaceous plants. Solanesol plays an important role in the interactions between plants and environmental factors such as pathogen infections and moderate-to-high temperatures. Additionally, it is a key intermediate for the pharmaceutical synthesis of ubiquinone-based drugs such as coenzyme Q10 and vitamin K2, and anti-cancer agent synergizers such as N-solanesyl-N,N′-bis(3,4-dimethoxybenzyl) ethylenediamine (SDB). In plants, solanesol is formed by the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway within plastids. Solanesol’s biosynthetic pathway involves the generation of C5 precursors, followed by the generation of direct precursors, and then the biosynthesis and modification of terpenoids; the first two stages of this pathway are well understood. Based on the current understanding of solanesol biosynthesis, we here review the key enzymes involved, including 1-deoxy-d-xylulose 5-phosphate synthase (DXS), 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR), isopentenyl diphosphate isomerase (IPI), geranyl geranyl diphosphate synthase (GGPPS), and solanesyl diphosphate synthase (SPS), as well as their biological functions. Notably, studies on microbial heterologous expression and overexpression of key enzymatic genes in tobacco solanesol biosynthesis are of significant importance for medical uses of tobacco.

[Effects of copper on biodegradation mechanism of trichloroethylene by mixed microorganisms]

We isolated and enriched mixed microorganisms SWA1 from landfill cover soils supplemented with trichloroethylene (TCE). The microbial mixture could degrade TCE effectively under aerobic conditions. Then, we investigated the effect of copper ion (0 to 15 μmol/L) on TCE biodegradation. Results show that the maximum TCE degradation speed was 29.60 nmol/min with 95.75% degradation when copper ion was at 0.03 μmol/L. In addition, genes encoding key enzymes during biodegradation were analyzed by Real-time quantitative reverse transcription PCR (RT-qPCR). The relative expression abundance of pmoA gene (4.22E-03) and mmoX gene (9.30E-06) was the highest when copper ion was at 0.03 μmol/L. Finally, we also used MiSeq pyrosequencing to investigate the diversity of microbial community. Methylocystaceae that can co-metabolic degrade TCE were the dominant microorganisms; other microorganisms with the function of direct oxidation of TCE were also included in SWA1 and the microbial diversity decreased significantly along with increasing of copper ion concentration. Based on the above results, variation of copper ion concentration affected the composition of SWA1 and degradation mechanism of TCE. The degradation mechanism of TCE included co-metabolism degradation of methanotrophs and oxidation metabolism directly at copper ion of 0.03 μmol/L. When copper ion at 5 μmol/L (biodegradation was 84.75%), the degradation mechanism of TCE included direct-degradation and co-metabolism degradation of methanotrophs and microorganisms containing phenol hydroxylase. Therefore, biodegradation of TCE by microorganisms was a complicated process, the degradation mechanism included co-metabolism degradation of methanotrophs and bio-oxidation of non-methanotrophs.

Flavourzyme, an Enzyme Preparation with Industrial Relevance: Automated Nine-Step Purification and Partial Characterization of Eight Enzymes

Flavourzyme is sold as a peptidase preparation from Aspergillus oryzae. The enzyme preparation is widely and diversely used for protein hydrolysis in industrial and research applications. However, detailed information about the composition of this mixture is still missing due to the complexity. The present study identified eight key enzymes by mass spectrometry and partially by activity staining on native polyacrylamide gels or gel zymography. The eight enzymes identified were two aminopeptidases, two dipeptidyl peptidases, three endopeptidases, and one α-amylase from the A. oryzae strain ATCC 42149/RIB 40 (yellow koji mold). Various specific marker substrates for these Flavourzyme enzymes were ascertained. An automated, time-saving nine-step protocol for the purification of all eight enzymes within 7 h was designed. Finally, the purified Flavourzyme enzymes were biochemically characterized with regard to pH and temperature profiles and molecular sizes.

Review of aerobic glycolysis and its key enzymes - new targets for lung cancer therapy

Most tumor cells show different metabolic pathways than normal cells. Even under the conditions of sufficient oxygen, they produce energy by a high rate of glycolysis followed by lactic acid fermentation in the cytosol, which is known as aerobic glycolysis or the Warburg effect. Lung cancer is a malignant tumor with one of the highest incidence and mortality rates in the world at present. However, the exact mechanisms underlying lung cancer development remain unclear. The three key enzymes of glycolysis are hexokinase, phosphofructokinase, and pyruvate kinase. Lactate dehydrogenase catalyzes the transfer of pyruvate to lactate. All four enzymes have been reported to be overexpressed in tumors, including lung cancer, and can be regulated by many oncoproteins to promote tumor proliferation, migration, and metastasis with dependence or independence of glycolysis. The discovery of aerobic glycolysis in the 1920s has provided new means and potential therapeutic targets for lung cancer.

Thermophilic fermentation of acetoin and 2,3-butanediol by a novel Geobacillus strain

BACKGROUND

Acetoin and 2,3-butanediol are two important biorefinery platform chemicals. They are currently fermented below 40°C using mesophilic strains, but the processes often suffer from bacterial contamination.

RESULTS

This work reports the isolation and identification of a novel aerobic Geobacillus strain XT15 capable of producing both of these chemicals under elevated temperatures, thus reducing the risk of bacterial contamination. The optimum growth temperature was found to be between 45 and 55°C and the medium initial pH to be 8.0. In addition to glucose, galactose, mannitol, arabionose, and xylose were all acceptable substrates, enabling the potential use of cellulosic biomass as the feedstock. XT15 preferred organic nitrogen sources including corn steep liquor powder, a cheap by-product from corn wet-milling. At 55°C, 7.7 g/L of acetoin and 14.5 g/L of 2,3-butanediol could be obtained using corn steep liquor powder as a nitrogen source. Thirteen volatile products from the cultivation broth of XT15 were identified by gas chromatography-mass spectrometry. Acetoin, 2,3-butanediol, and their derivatives including a novel metabolite 2,3-dihydroxy-3-methylheptan-4-one, accounted for a total of about 96% of all the volatile products. In contrast, organic acids and other products were minor by-products. α-Acetolactate decarboxylase and acetoin:2,6-dichlorophenolindophenol oxidoreductase in XT15, the two key enzymes in acetoin metabolic pathway, were found to be both moderately thermophilic with the identical optimum temperature of 45°C.

CONCLUSIONS

Geobacillus sp. XT15 is the first naturally occurring thermophile excreting acetoin and/or 2,3-butanediol. This work has demonstrated the attractive prospect of developing it as an industrial strain in the thermophilic fermentation of acetoin and 2,3-butanediol with improved anti-contamination performance. The novel metabolites and enzymes identified in XT15 also indicated its strong promise as a precious biological resource. Thermophilic fermentation also offers great prospect for improving its yields and efficiencies. This remains a core aim for future work.