Biotechnological production and applications of statins. Appl Microbiol Biotechnol. 2010;85:869-883. [PMID: 19820926 DOI: 10.1007/s00253-009-2239-6]

Molecular Mechanism of Mok I Gene Overexpression in Enhancing Monacolin K Production in Monascus pilosus

Monascus species are capable of producing various active metabolites, including monacolin K (MK) and pigments. Studies have shown that the overexpression of the mok I gene from the MK synthesis gene cluster in Monascus species can significantly increase MK production; however, the molecular mechanism has not yet been fully elucidated. Therefore, this study focused on the mok I gene of Monascus pilosus to construct overexpression strains of the mok I gene, resulting in high-yield MK production. Sixteen positive transformants were obtained, seven of which produced 9.63% to 41.39% more MK than the original strain, with no citrinin detected in any of the transformants. The qRT-PCR results revealed that the expression levels of mok I in the transformed strains TI-13, TI-24, and TI-25 increased by more than 50% compared to the original strain at various fermentation times, with the highest increase being 10.9-fold. Furthermore, multi-omics techniques were used to analyze the molecular mechanisms underlying enhanced MK production in transformed strains. The results indicated that mok I overexpression may enhance MK synthesis in M. pilosus by regulating the expression of key genes (such as MAO, HPD, ACX, and PLC) and the synthesis levels of key metabolites (such as delta-tocopherol and alpha-linolenic acid) in pathways linked to the biosynthesis of cofactors, the biosynthesis of unsaturated fatty acids, tyrosine metabolism, ubiquinone and other terpenoid-quinone biosynthesis, alpha-linolenic acid metabolism, and glycerophospholipid metabolism. These findings provide a theoretical basis for further study of the metabolic regulation of MK in Monascus species and for effectively enhancing their MK production.

Regulatory effects of statins on Akt signaling for prevention of cancers

Statins, which are primarily used as lipid-lowering drugs, have been found to exhibit anti-tumor effects through modulating and interfering with various signaling pathways. In observational studies, statin use has been associated with a significant reduction in the progression of various cancers, including colon, lung, prostate, pancreas, and esophagus cancer, as well as melanoma and B and T cell lymphoma. The mevalonate pathway, which is affected by statins, plays a crucial role in activating Rho, Ras, and Rab proteins, thereby impacting the proliferation and apoptosis of tumor cells. Statins block this pathway, leading to the inhibition of isoprenoid units, which are critical for the activation of these key proteins, thereby affecting cancer cell behavior. Additionally, statins affect MAPK and Cdk2, which in turn reduce the expression of p21 and p27 cyclin-dependent kinase inhibitors. Akt signaling plays a crucial role in key cancer cell features like proliferation, invasion, and apoptosis by activating multiple effectors in downstream pathways such as FOXO, PTEN, NF-κB, GSK3β, and mTOR. The PI3K/Akt signaling is necessary for many events in the metastatic pathway and has been implicated in the resistance to cytostatic drugs. The Akt/PTEN axis is currently attracting great interest for its role in carcinogenesis. Statins have been shown to activate the purinergic receptor P2X7 and affect Akt signaling, which may have important anti-cancer effects. Hence, targeting Akt shows promise as an effective approach to cancer prevention and therapy. This review aims to provide a comprehensive discussion on the specific impact of statins through Akt signaling in different types of cancer.

Analysis of Whole-Genome for Identification of Seven Penicillium Species with Significant Economic Value

The Penicillium genus exhibits a broad global distribution and holds substantial economic value in sectors including agriculture, industry, and medicine. Particularly in agriculture, Penicillium species significantly impact plants, causing diseases and contamination that adversely affect crop yields and quality. Timely detection of Penicillium species is crucial for controlling disease and preventing mycotoxins from entering the food chain. To tackle this issue, we implement a novel species identification approach called Analysis of whole GEnome (AGE). Here, we initially applied bioinformatics analysis to construct specific target sequence libraries from the whole genomes of seven Penicillium species with significant economic impact: P. canescens, P. citrinum, P. oxalicum, P. polonicum, P. paneum, P. rubens, and P. roqueforti. We successfully identified seven Penicillium species using the target we screened combined with Sanger sequencing and CRISPR-Cas12a technologies. Notably, based on CRISPR-Cas12a technology, AGE can achieve rapid and accurate identification of genomic DNA samples at a concentration as low as 0.01 ng/µL within 30 min. This method features high sensitivity and portability, making it suitable for on-site detection. This robust molecular approach provides precise fungal species identification with broad implications for agricultural control, industrial production, clinical diagnostics, and food safety.

Screening and genetic engineering of marine-derived Aspergillus terreus for high-efficient production of lovastatin

BACKGROUND

Lovastatin has widespread applications thanks to its multiple pharmacological effects. Fermentation by filamentous fungi represents the major way of lovastatin production. However, the current lovastatin productivity by fungal fermentation is limited and needs to be improved.

RESULTS

In this study, the lovastatin-producing strains of Aspergillus terreus from marine environment were screened, and their lovastatin productions were further improved by genetic engineering. Five strains of A. terreus were isolated from various marine environments. Their secondary metabolites were profiled by metabolomics analysis using Ultra Performance Liquid Chromatography-Mass spectrometry (UPLC-MS) with Global Natural Products Social Molecular Networking (GNPS), revealing that the production of secondary metabolites was variable among different strains. Remarkably, the strain of A. terreus MJ106 could principally biosynthesize the target drug lovastatin, which was confirmed by High Performance Liquid Chromatography (HPLC) and gene expression analysis. By one-factor experiment, lactose was found to be the best carbon source for A. terreus MJ106 to produce lovastatin. To improve the lovastatin titer in A. terreus MJ106, genetic engineering was applied to this strain. Firstly, a series of strong promoters was identified by transcriptomic and green fluorescent protein reporter analysis. Then, three selected strong promoters were used to overexpress the transcription factor gene lovE encoding the major transactivator for lov gene cluster expression. The results revealed that compared to A. terreus MJ106, all lovE over-expression mutants exhibited significantly more production of lovastatin and higher gene expression. One of them, LovE-b19, showed the highest lovastatin productivity at a titer of 1512 mg/L, which represents the highest production level reported in A. terreus.

CONCLUSION

Our data suggested that combination of strain screen and genetic engineering represents a powerful tool for improving the productivity of fungal secondary metabolites, which could be adopted for large-scale production of lovastatin in marine-derived A. terreus.

Statins-From Fungi to Pharmacy

Statins have been used in the treatment of hyperlipidemia, both as monotherapy and in combination therapy. Natural fermentation processes of fungi such as Monascus spp., Penicillium spp., Aspergillus terreus, and Pleurotus ostreatus have given rise to natural statins. Compactin (mevastatin), the original naturally occurring statin, is the primary biotransformation substrate in the manufacturing process of marketed drugs. Statins are classified into natural, semi-synthetic derivatives of natural statins, and synthetic ones. Synthetic statins differ from natural statins in their structural composition, with the only common feature being the HMG-CoA-like moiety responsible for suppressing HMG-CoA reductase. Statins do not differ significantly regarding their pleiotropic and adverse effects, but their characteristics depend on their pharmacokinetic parameters and chemical properties. This paper focuses on describing the processes of obtaining natural statins, detailing the pharmacokinetics of available statins, divided into natural and synthetic, and indicating their pleiotropic effects.

Transcriptome Identification and Analysis of Fatty Acid Desaturase Gene Expression at Different Temperatures in Tausonia pullulans 6A7

Tausonia pullulans 6A7 is a low-temperature yeast strain that can produce lipases. Yeast, which is made up of chassis cells, is an important part of synthetic biology, and the use of the lipase-producing properties of T. pullulans 6A7 for the production of fatty acids provides a new pathway for targeted synthesis in yeast cell factories. In this study, we performed RNA-seq on lipase-producing T. pullulans 6A7 at different temperatures (15 °C, 20 °C, 20 °C without corn oil, and 25 °C). Therefore, a total of 8455 differentially expressed genes were screened, and 16 of them were FAD candidate genes. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of group A (15 °C) vs. group D (25 °C) showed that the pathways of fatty acid biosynthesis (map00061) and the biosynthesis of unsaturated fatty acids (map01040) were significantly enriched. In the proposed temporal analysis of differentially expressed genes among the four temperature modulations, we found differentially expressed genes in nine clusters that had the same expression trends; these genes may be jointly involved in multiple biological processes in T. pullulans 6A7. In addition, we found 16 FAD candidate genes involved in fatty acid biosynthesis, and the expression of these genes had similar expression in the transcriptome trends with the different temperature treatments. These findings will help in future in-depth studies of the function and molecular mechanisms of these important FAD genes involved in fatty acid metabolism in yeast, and they could also be conducive to the establishment of a cellular factory for targeted fatty acid production by using yeast.

Elucidation of the melitidin biosynthesis pathway in pummelo

Specialized plant metabolism is a rich resource of compounds for drug discovery. The acylated flavonoid glycoside melitidin is being developed as an anti-cholesterol statin drug candidate, but its biosynthetic route in plants has not yet been fully characterized. Here, we describe the gene discovery and functional characterization of a new flavonoid gene cluster (UDP-glucuronosyltransferases (CgUGTs), 1,2 rhamnosyltransferase (Cg1,2RhaT), acyltransferases (CgATs)) that is responsible for melitidin biosynthesis in pummelo (Citrus grandis (L.) Osbeck). Population variation analysis indicated that the tailoring of acyltransferases, specific for bitter substrates, mainly determine the natural abundance of melitidin. Moreover, 3-hydroxy-3-methylglutaryl-CoA reductase enzyme inhibition assays showed that the product from this metabolic gene cluster, melitidin, may be an effective anti-cholesterol statin drug candidate. Co-expression of these clustered genes in Nicotiana benthamiana resulted in the formation of melitidin, demonstrating the potential for metabolic engineering of melitidin in a heterologous plant system. This study establishes a biosynthetic pathway for melitidin, which provides genetic resources for the breeding and genetic improvement of pummelo aimed at fortifying the content of biologically active metabolites.

Drastic Synergy of Lovastatin and Antrodia camphorata Extract Combination against PC3 Androgen-Refractory Prostate Cancer Cells, Accompanied by AXL and Stemness Molecules Inhibition

Prostate cancer (PC) is the second most frequently diagnosed cancer and the fifth leading cause of cancer-related death in males worldwide. Early-stage PC patients can benefit from surgical, radiation, and hormonal therapies; however, once the tumor transitions to an androgen-refractory state, the efficacy of treatments diminishes considerably. Recently, the exploration of natural products, particularly dietary phytochemicals, has intensified in response to addressing this prevailing medical challenge. In this study, we uncovered a synergistic effect from combinatorial treatment with lovastatin (an active component in red yeast rice) and Antrodia camphorata (AC, a folk mushroom) extract against PC3 human androgen-refractory PC cells. This combinatorial modality resulted in cell cycle arrest at the G0/G1 phase and induced apoptosis, accompanied by a marked reduction in molecules responsible for cellular proliferation (p-Rb/Rb, Cyclin A, Cyclin D1, and CDK1), aggressiveness (AXL, p-AKT, and survivin), and stemness (SIRT1, Notch1, and c-Myc). In contrast, treatment with either AC or lovastatin alone only exerted limited impacts on the cell cycle, apoptosis, and the aforementioned signaling molecules. Notably, significant reductions in canonical PC stemness markers (CD44 and CD133) were observed in lovastatin/AC-treated PC3 cells. Furthermore, lovastatin and AC have been individually examined for their anti-PC properties. Our findings elucidate a pioneering discovery in the synergistic combinatorial efficacy of AC and clinically viable concentrations of lovastatin on PC3 PC cells, offering novel insights into improving the therapeutic effects of dietary natural products for future strategic design of therapeutics against androgen-refractory prostate cancer.

Exploitation of Sugarcane Bagasse and Environmentally Sustainable Production, Purification, Characterization, and Application of Lovastatin by Aspergillus terreus AUMC 15760 under Solid-State Conditions

Using the internal transcribed spacer (ITS) region for identification, three strains of Aspergillus terreus were identified and designated AUMC 15760, AUMC 15762, and AUMC 15763 for the Assiut University Mycological Centre culture collection. The ability of the three strains to manufacture lovastatin in solid-state fermentation (SSF) using wheat bran was assessed using gas chromatography-mass spectroscopy (GC-MS). The most potent strain was strain AUMC 15760, which was chosen to ferment nine types of lignocellulosic waste (barley bran, bean hay, date palm leaves, flax seeds, orange peels, rice straw, soy bean, sugarcane bagasse, and wheat bran), with sugarcane bagasse turning out to be the best substrate. After 10 days at pH 6.0 at 25 °C using sodium nitrate as the nitrogen source and a moisture content of 70%, the lovastatin output reached its maximum quantity (18.2 mg/g substrate). The medication was produced in lactone form as a white powder in its purest form using column chromatography. In-depth spectroscopy examination, including ¹H, ¹³C-NMR, HR-ESI-MS, optical density, and LC-MS/MS analysis, as well as a comparison of the physical and spectroscopic data with published data, were used to identify the medication. At an IC₅₀ of 69.536 ± 5.73 µM, the purified lovastatin displayed DPPH activity. Staphylococcus aureus and Staphylococcus epidermidis had MICs of 1.25 mg/mL, whereas Candida albicans and Candida glabrata had MICs of 2.5 mg/mL and 5.0 mg/mL, respectively, against pure lovastatin. As a component of sustainable development, this study offers a green (environmentally friendly) method for using sugarcane bagasse waste to produce valuable chemicals and value-added commodities.

Role of AtYap1 in the reactive oxygen species regulation of lovastatin production in Aspergillus terreus

Lovastatin has great medical and economic importance, and its production in Aspergillus terreus is positively regulated at transcriptional level, by reactive oxygen species (ROS) generated during idiophase. To investigate the role of the transcription factor Yap1 in the regulation of lovastatin biosynthesis by ROS, an orthologue of yap1 was identified in A. terreus TUB F-514 and knocked down (silenced) by RNAi. Results confirmed that the selected knockdown strain (Siyap1) showed decreased yap1 expression in both culture systems (submerged and solid-state fermentation). Transformants showed higher sensitivity to oxidative stress. Interestingly, knockdown mutant showed higher ROS levels in idiophase and an important increase in lovastatin production in submerged and solid-state fermentations: 60 and 70% increase, respectively. Furthermore, sporulation also increased by 600%. This suggested that AtYap1 was functioning as a negative regulator of the biosynthetic genes, and that lack of AtYap1 in the mutants would be derepressing these genes and could explain increased production. However, we have shown that lovastatin production is proportional to ROS levels, so ROS increase in the mutants alone could also be the cause of production increase. In this work, when ROS levels were decreased with antioxidant, to the levels shown by the parental strain, the lovastatin production and kinetics were similar to the ones of the parental strain. This means that AtYap1 does not regulate lovastatin biosynthetic genes, and that production increase observed in the knockdown strain was an indirect effect caused by ROS increase. This conclusion is compared with studies on other secondary metabolites produced by other fungal species. KEY POINTS: • ROS regulates lovastatin biosynthesis at transcriptional level, in solid-state, and in submerged fermentations. • ATyap1 knockdown mutants showed important lovastatin production increases (60 and 70%) and higher ROS levels. • When ROS were decreased in the silenced mutant to the parental strain's level, lovastatin kinetics were identical to the parental strain's.

Statins: Beneficial Effects in Treatment of COVID-19

The recent viral disease COVID-19 has attracted much attention. The disease is caused by SARS-CoV-19 virus which has different variants and mutations. The mortality rate of SARS-CoV-19 is high and efforts to establish proper therapeutic solutions are still ongoing. Inflammation plays a substantial part in the pathogenesis of this disease causing mainly lung tissue destruction and eventually death. Therefore, anti-inflammatory drugs or treatments that can inhibit inflammation are important options. Various inflammatory pathways such as nuclear factor Kappa B (NF-κB), signal transducer of activators of transcription (STAT), nod-like receptor family protein 3 (NLRP), toll-like receptors (TLRs), mitogen-activated protein kinase (MAPK), and mammalian target of rapamycin (mTOR) pathways and mediators, such as interleukin (IL)-6, IL-1β, tumor necrosis factor-α (TNF-α), and interferon-γ (INF-γ), cause cell apoptosis, reduce respiratory capacity and oxygen supply, eventually inducing respiratory system failure and death. Statins are well known for controlling hypercholesterolemia and may serve to treat COVID-19 due to their pleiotropic effects among which are anti-inflammatory in nature. In this chapter, the anti-inflammatory effects of statins and their possible beneficial effects in COVID-19 treatment are discussed. Data were collected from experimental and clinical studies in English (1998-October 2022) from Google Scholar, PubMed, Scopus, and the Cochrane Library.

Mining new meroterpenoids from the marine red alga-derived endophytic Penicillium chermesinum EN-480 by comparative transcriptome analysis

As the development of genetic and bioinformatic, the strategy of "bottom-up", combined with genome and transcriptome techniques, was considered as an efficient and practical method to break through the limitation of traditional discovery of natural products. Generally, comparative transcriptome analysis could be useful to guide the optimization of fungal cultivation conditions in which the transcriptional level of interesting compounds is higher. The transcriptome analysis of the algal endophytic fungus Penicillium chermesinum EN-480 indicated that fermentation of this fungus in modified rice solid medium could produce some metabolites different from those cultivated in other media. Four new meroterpenoids (compounds 1-4, namely, chermesins E-H) were characterized and their structures were determined by HRESIMS and NMR spectra. The absolute configurations were confirmed by NOESY experiments, X-ray diffraction analysis, and comparison of ECD cotton effects. Antimicrobial activities against human- and aqua-bacteria as well as against plant-pathogenic fungi were assayed. The plausible biosynthesis pathway of these compounds was discussed.

Lovastatin production by an oleaginous fungus, Aspergillus terreus KPR12 using sago processing wastewater (SWW)

Background

Lovastatin is one of the first statins to be extensively used for its cholesterol-lowering ability. It is commercially produced by fermentation. Species belonging to the genus Aspergillus are well-studied fungi that have been widely used for lovastatin production. In the present study, we produced lovastatin from sago processing wastewater (SWW) under submerged fermentation using oleaginous fungal strains, A. terreus KPR12 and A. caespitosus ASEF14.

Results

The intra- and extracellular concentrations of lovastatin produced by A. terreus KPR12 and A. caespitosus ASEF14 were lactonized. Because A. caespitosus ASEF14 produced a negligible amount of lovastatin, further kinetics of lovastatin production in SWW was studied using the KPR12 strain for 9 days. Lovastatin concentrations in the intra- and extracellular fractions of the A. terreus KPR12 cultured in a synthetic medium (SM) were 117.93 and 883.28 mg L–1, respectively. However, these concentrations in SWW were 142.23 and 429.98 mg L–1, respectively. The yeast growth inhibition bioassay confirmed the antifungal property of fungal extracts. A. terreus KPR12 showed a higher inhibition zone of 14 mm than the ASEF14 strain. The two-way analysis of variance (ANOVA; p < 0.01) showed significant differences in the localization pattern, fungal strains, growth medium, and their respective interactions. The lovastatin yield coefficient values were 0.153 g g–1 on biomass (YLOV/X) and 0.043 g g–1 on the substrate, starch (YLOV/S). The pollutant level of treated SWW exhibited a reduction in total solids (TS, 59%), total dissolved solids (TDS, 68%), biological oxygen demand (BOD, 79.5%), chemical oxygen demand (COD, 57.1%), phosphate (88%), cyanide (65.4%), and void of nutrients such as nitrate (100%), and ammonia (100%).

Conclusion

The starch-rich wastewater serves as a suitable medium for A. terreus KPR12 for the production of lovastatin. It simultaneously decontaminates the sago processing wastewater, enabling its reuse for irrigation/recreation.

Graphical Abstract

Morphological, physiological, biochemical and molecular characterization of statin-producing Penicillium microfungi isolated from little-explored tropical ecosystems

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Natural statins produced by microfungi are extremely successful drugs.

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Fungal producers of statins were isolated from soils of unique tropical habitats.

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Three novel statin-producing Penicillium strains were characterized and identified.

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Pravastatin was produced by the identified fungal cultures directly.

As hypercholesterolemia is a primary risk factor for coronary artery disease and stroke, there is now an increasing demand for cholesterol-lowering drugs. Statins are a group of extremely successful drugs that lower the cholesterol level in the blood. Natural statins are produced by fermentation using different species of microorganisms. The overall aim of the present study was to identify statin-producing microfungi, which were isolated from different types of little-explored mangrove and oil palm plantation soils. Isolated fungal cultures were characterized on the basis of morphological, physiological, biochemical, and molecular features. Morphological variability was detected amongst the fungal isolates in regard to colony morphology, conidiophores structures, and conidia coloration. Based on their physiological properties and enzyme assays, rapid differentiation of statin-producing isolates was achieved. Further molecular characterization allowed reliable identification of the selected Penicillium microfungi up to the species level. The identified Penicillium cintrinum ESF2M, Penicillium brefeldianum ESF21P, and Penicillium janthinellum ESF26P strains have a scientific interest as novel wild-type producers of natural statins.

Shortening Synthetic Routes to Small Molecule Active Pharmaceutical Ingredients Employing Biocatalytic Methods

Biocatalysis, using enzymes for organic synthesis, has emerged as powerful tool for the synthesis of active pharmaceutical ingredients (APIs). The first industrial biocatalytic processes launched in the first half of the last century exploited whole-cell microorganisms where the specific enzyme at work was not known. In the meantime, novel molecular biology methods, such as efficient gene sequencing and synthesis, triggered breakthroughs in directed evolution for the rapid development of process-stable enzymes with broad substrate scope and good selectivities tailored for specific substrates. To date, enzymes are employed to enable shorter, more efficient, and more sustainable alternative routes toward (established) small molecule APIs, and are additionally used to perform standard reactions in API synthesis more efficiently. Herein, large-scale synthetic routes containing biocatalytic key steps toward >130 APIs of approved drugs and drug candidates are compared with the corresponding chemical protocols (if available) regarding the steps, reaction conditions, and scale. The review is structured according to the functional group formed in the reaction.

Yellow Yeast Rice Prepared Using Aspergillus terreus DSMK01 Lowers Cholesterol Levels by Stimulating Bile Salt Export Pump in Subjects with Mild-to-Moderate Hypercholesterolemia: A Randomized Controlled Trial

SCOPE

Aspergillus terreus is an industrial microorganism used in the brewing and sauce industries. It produces monacolin K, a natural statin. The study conducted an 8-week randomized controlled trial with hypercholesterolemic subjects to examine the hypocholesterolemic effects and mechanisms of supplementation with yellow yeast rice (YYR) prepared by growing Aspergillus fungi on steamed rice.

METHODS AND RESULTS

YYR supplementation markedly reduced total cholesterol, LDL, and apolipoprotein B100 levels in plasma compared with the placebo. In addition, YYR induced a significantly increased ATP binding cassette subfamily B member 11 (ABCB11) gene expression compared with the placebo, indicating the role of YYR in lowering intrahepatic cholesterol availability by stimulating the bile salt export pump. Upregulation of LDL receptor (LDLR) and 3-methylglutaryl-CoA reductase (HMGCR) gene expressions provided additional evidence to support the role of YYR in reducing hepatic cholesterol availability. Plasma metabolomic profiling revealed the possibility of diminishing bile acid absorption. Finally, Spearman rank analysis showed correlations of plasma cholesterol profiles with HMGCR and LDLR gene expressions (negative) and plasma bile acids (positive). Plasma bile acids also correlated with ABCB11 (negative) and LDLR (positive) gene expressions.

CONCLUSION

These findings suggest that daily YYR supplementation exerted hypocholesterolemic effects in mild-to-moderate hypercholesterolemic subjects by reducing intrahepatic cholesterol availability through stimulating bile salt export pumps and inhibiting cholesterol biosynthesis.

Fungal quinones: diversity, producers, and applications of quinones from Aspergillus, Penicillium, Talaromyces, Fusarium, and Arthrinium

Quinones represent an important group of highly structurally diverse, mainly polyketide-derived secondary metabolites widely distributed among filamentous fungi. Many quinones have been reported to have important biological functions such as inhibition of bacteria or repression of the immune response in insects. Other quinones, such as ubiquinones are known to be essential molecules in cellular respiration, and many quinones are known to protect their producing organisms from exposure to sunlight. Most recently, quinones have also attracted a lot of industrial interest since their electron-donating and -accepting properties make them good candidates as electrolytes in redox flow batteries, like their often highly conjugated double bond systems make them attractive as pigments. On an industrial level, quinones are mainly synthesized from raw components in coal tar. However, the possibility of producing quinones by fungal cultivation has great prospects since fungi can often be grown in industrially scaled bioreactors, producing valuable metabolites on cheap substrates. In order to give a better overview of the secondary metabolite quinones produced by and shared between various fungi, mainly belonging to the genera Aspergillus, Penicillium, Talaromyces, Fusarium, and Arthrinium, this review categorizes quinones into families such as emodins, fumigatins, sorbicillinoids, yanuthones, and xanthomegnins, depending on structural similarities and information about the biosynthetic pathway from which they are derived, whenever applicable. The production of these quinone families is compared between the different genera, based on recently revised taxonomy. KEY POINTS: • Quinones represent an important group of secondary metabolites widely distributed in important fungal genera such as Aspergillus, Penicillium, Talaromyces, Fusarium, and Arthrinium. • Quinones are of industrial interest and can be used in pharmacology, as colorants and pigments, and as electrolytes in redox flow batteries. • Quinones are grouped into families and compared between genera according to the revised taxonomy.

A Novel Statin Compound from Monacolin J Produced Using CYP102A1-Catalyzed Regioselective C-Hydroxylation

Statins inhibit the 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMG-CoA reductase), which is the rate-limiting enzyme in cholesterol biosynthesis. Statin therapy reduces morbidity and mortality in those who are at high risk of cardiovascular disease. Monacolin J is a statin compound, which is an intermediate in the lovastatin biosynthesis pathway, in the fungus Aspergillus terreus. It is also found in red yeast rice, which is made by culturing rice with the yeast Monascus purpureus. Monacolin J has a hydroxyl substituent at position C’-8 of monacolin L. Here, a new statin derivative from monacolin J was made through the catalysis of CYP102A1 from Bacillus megaterium. A set of CYP102A1 mutants of monacolin J hydroxylation with high catalytic activity was screened. The major hydroxylated product was C-6′a-hydroxymethyl monacolin J, whose structure was confirmed using LC–MS and NMR analysis. The C-6′a-hydroxymethyl monacolin J has never been reported before. It showed a greater ability to inhibit HMG-CoA reductase than the monacolin J substrate itself. Human liver microsomes and human CYP3A4 also showed the ability to catalyze monacolin J in producing the same product of the CYP102A1-catalyzed reaction. This result motivates a new strategy for the development of a lead for the enzymatic and chemical processes to develop statin drug candidates.

Plant associated fungal endophytes as a source of natural bioactive compounds

Endophytes are a potent source of bioactive compounds that mimic plant-based metabolites. The relationship of host plant and endophyte is significantly associated with alteration in fungal colonisation and the extraction of endophyte-derived bioactive compounds. Screening of fungal endophytes and their relationship with host plants is essential for the isolation of bioactive compounds. Numerous bioactive compounds with antioxidant, antimicrobial, anticancer, and immunomodulatory properties are known to be derived from fungal endophytes. Bioinformatics tools along with the latest techniques such as metabolomics, next-generation sequencing, and metagenomics multilocus sequence typing can potentially fill the gaps in fungal endophyte research. The current review article focuses on bioactive compounds derived from plant-associated fungal endophytes and their pharmacological importance. We conclude with the challenges and opportunities in the research area of fungal endophytes.

Increasing Lovastatin Production by Re-routing the Precursors Flow of Aspergillus terreus via Metabolic Engineering

Lovastatin is an anti-cholesterol medicine that is commonly prescribed to manage cholesterol levels, and minimise the risk of suffering from heart-related diseases. Aspergillus terreus (ATCC 20542) supplied with carbohydrates or sugar alcohols can produce lovastatin. The present work explored the application of metabolic engineering in A. terreus to re-route the precursor flow towards the lovastatin biosynthetic pathway by simultaneously overexpressing the gene for acetyl-CoA carboxylase (acc) to increase the precursor flux, and eliminate ( +)-geodin biosynthesis (a competing secondary metabolite) by removing the gene for emodin anthrone polyketide synthase (gedC). Alterations to metabolic flux in the double mutant (gedCΔ*acc^ox) strain and the effects of using two different substrate formulations were examined. The gedCΔ*acc^ox strain, when cultivated with a mixture of glycerol and lactose, significantly (p < 0.05) increased the levels of metabolic precursors malonyl-CoA (48%) and acetyl-CoA (420%), completely inhibited the (+)-geodin biosynthesis, and increased the level of lovastatin [152 mg/L; 143% higher than the wild-type (WT) strain]. The present work demonstrated how the manipulation of A. terreus metabolic pathways could increase the efficiency of carbon flux towards lovastatin, thus elevating its overall production and enabling the use of glycerol as a substrate source. As such, the present work also provides a framework model for other medically or industrially important fungi to synthesise valuable compounds using sustainable carbon sources.

Current Practices for Reference Gene Selection in RT-qPCR of Aspergillus: Outlook and Recommendations for the Future

Aspergillus is a genus of filamentous fungi with vast geographic and ecological distributions. Species within this genus are clinically, agriculturally and biotechnologically relevant, leading to increasing interest in elucidating gene expression dynamics of key metabolic and physiological processes. Reverse-transcription quantitative Polymerase Chain Reaction (RT-qPCR) is a sensitive and specific method of quantifying gene expression. A crucial step for comparing RT-qPCR results between strains and experimental conditions is normalisation to experimentally validated reference gene(s). In this review, we provide a critical analysis of current reference gene selection and validation practices for RT-qPCR gene expression analyses of Aspergillus. Of 90 primary research articles obtained through our PubMed query, 17 experimentally validated the reference gene(s) used. Twenty reference genes were used across the 90 studies, with beta-tubulin being the most used reference gene, followed by actin, 18S rRNA and glyceraldehyde 3-phosphate dehydrogenase. Sixteen of the 90 studies used multiple reference genes for normalisation. Failing to experimentally validate the stability of reference genes can lead to conflicting results, as was the case for four studies. Overall, our review highlights the need to experimentally validate reference genes in RT-qPCR studies of Aspergillus.

An overview on the biosynthesis and metabolic regulation of monacolin K/lovastatin

Lovastatin/monacolin K (MK) is used as a lipid lowering drug, due to its effective hypercholesterolemic properties, comparable to synthetic statins. Lovastatin's biosynthetic pathway and gene cluster composition have been studied in depth in Aspergillus terreus. Evidence shows that the MK biosynthetic pathway and gene cluster in Monascus sp. are similar to those of lovastatin in A. terreus. Currently, research efforts have been focusing on the metabolic regulation of MK/lovastatin synthesis, and the evidence shows that a combination of extracellular and intracellular factors is essential for proper MK/lovastatin metabolism. Here, we comprehensively review the research progress on MK/lovastatin biosynthetic pathways, its synthetic precursors and inducing substances and metabolic regulation, with a view to providing reference for future research on fungal metabolism regulation and metabolic engineering for MK/lovastatin production.

Complete genome sequence of lovastatin producer Aspergillus terreus ATCC 20542 and evaluation of genomic diversity among A. terreus strains

In the present study, the complete genome of a filamentous fungus Aspergillus terreus ATCC 20542 was sequenced, assembled, and annotated. This strain is mainly recognized for being a model wild-type lovastatin producer and a parental strain of high-yielding industrial mutants. It is also a microorganism with a rich repertoire of secondary metabolites that has been a subject of numerous bioprocess-related studies. In terms of continuity, the genomic sequence provided in this work is of the highest quality among all the publicly available genomes of A. terreus strains. The comparative analysis revealed considerable diversity with regard to the catalog of biosynthetic gene clusters found in A. terreus. Even though the cluster of lovastatin biosynthesis was found to be well-conserved at the species level, several unique genes putatively associated with metabolic functions were detected in A. terreus ATCC 20542 that were not detected in other investigated genomes. The analysis was conducted also in the context of the primary metabolic pathways (sugar catabolism, biomass degradation potential, organic acid production), where the visible differences in gene copy numbers were detected. However, the species-level genomic diversity of A. terreus was more evident for secondary metabolism than for the well-conserved primary metabolic pathways. The newly sequenced genome of A. terreus ATCC 20542 was found to harbor several unique sequences, which can be regarded as interesting subjects for future experimental efforts on A. terreus metabolism and fungal biosynthetic capabilities. KEY POINTS: • The high-quality genome of Aspergillus terreus ATCC 20542 has been assembled and annotated. • Comparative analysis with other sequenced Aspergillus terreus strains has revealed considerable diversity in biosynthetic gene repertoire, especially related to secondary metabolism. • The unique genomic features of A. terreus ATCC 20542 are discussed.

Identification and Characterization of a New Type III Polyketide Synthase from a Marine Yeast, Naganishia uzbekistanensis

A putative Type III Polyketide synthase (PKSIII) encoding gene was identified from a marine yeast, Naganishia uzbekistanensis strain Mo29 (UBOCC-A-208024) (formerly named as Cryptococcus sp.) isolated from deep-sea hydrothermal vents. This gene is part of a distinct phylogenetic branch compared to all known terrestrial fungal sequences. This new gene encodes a C-terminus extension of 74 amino acids compared to other known PKSIII proteins like Neurospora crassa. Full-length and reduced versions of this PKSIII were successfully cloned and overexpressed in a bacterial host, Escherichia coli BL21 (DE3). Both proteins showed the same activity, suggesting that additional amino acid residues at the C-terminus are probably not required for biochemical functions. We demonstrated by LC-ESI-MS/MS that these two recombinant PKSIII proteins could only produce tri- and tetraketide pyrones and alkylresorcinols using only long fatty acid chain from C8 to C16 acyl-CoAs as starter units, in presence of malonyl-CoA. In addition, we showed that some of these molecules exhibit cytotoxic activities against several cancer cell lines.

The Role of Structure and Biophysical Properties in the Pleiotropic Effects of Statins

Statins are a class of drugs used to lower low-density lipoprotein cholesterol and are amongst the most prescribed medications worldwide. Most statins work as a competitive inhibitor of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGR), but statin intolerance from pleiotropic effects have been proposed to arise from non-specific binding due to poor enzyme-ligand sensitivity. Yet, research into the physicochemical properties of statins, and their interactions with off-target sites, has not progressed much over the past few decades. Here, we present a concise perspective on the role of statins in lowering serum cholesterol levels, and how their reported interactions with phospholipid membranes offer a crucial insight into the mechanism of some of the more commonly observed pleiotropic effects of statin administration. Lipophilicity, which governs hepatoselectivity, is directly related to the molecular structure of statins, which dictates interaction with and transport through membranes. The structure of statins is therefore a clinically important consideration in the treatment of hypercholesterolaemia. This review integrates the recent biophysical studies of statins with the literature on the physiological effects and provides new insights into the mechanistic cause of statin pleiotropy, and prospective means of understanding the cholesterol-independent effects of statins.

New knowledge about the biosynthesis of lovastatin and its production by fermentation of Aspergillus terreus

Lovastatin, and its semisynthetic derivative simvastatine, has great medical and economic importance, besides great potential for other uses. In the last years, a deeper and more complex view of secondary metabolism regulation has emerged, with the incorporation of cluster-specific and global transcription factors, and their relation to signaling cascades, as well as the new level of epigenetic regulation. Recently, a new mechanism, which regulates lovastatin biosynthesis, at transcriptional level, has been discovered: reactive oxygen species (ROS) regulation; also new unexpected environmental stimuli have been identified, which induce the synthesis of lovastatin, like quorum sensing-type molecules and support stimuli. The present review describes this new panorama and uses this information, together with the knowledge on lovastatin biosynthesis and genomics, as the foundation to analyze literature on optimization of fermentation parameters and medium composition, and also to fully understand new strategies for strain genetic improvement. This new knowledge has been applied to the development of more effective culture media, with the addition of molecules like butyrolactone I, oxylipins, and spermidine, or with addition of ROS-generating molecules to increase internal ROS levels in the cell. It has also been applied to the development of new strategies to generate overproducing strains of Aspergillus terreus, including engineering of the cluster-specific transcription factor (lovE), global transcription factors like the ones implicated in ROS regulation (or even mitochondrial alternative respiration aox gen), or the global regulator LaeA. Moreover, there is potential to apply some of these findings to the development of novel unconventional production systems. KEY POINTS: • New findings in regulation of lovastatin biosynthesis, like ROS regulation. • Induction by unexpected stimuli: autoinducer molecules and support stimuli. • Recent reports on culture medium and process optimization from this stand point. • Applications to molecular genetic strain improvement methods and production systems.

Aspergillus: A Powerful Protein Production Platform

Aspergilli have been widely used in the production of organic acids, enzymes, and secondary metabolites for almost a century. Today, several GRAS (generally recognized as safe) Aspergillus species hold a central role in the field of industrial biotechnology with multiple profitable applications. Since the 1990s, research has focused on the use of Aspergillus species in the development of cell factories for the production of recombinant proteins mainly due to their natively high secretion capacity. Advances in the Aspergillus-specific molecular toolkit and combination of several engineering strategies (e.g., protease-deficient strains and fusions to carrier proteins) resulted in strains able to generate high titers of recombinant fungal proteins. However, the production of non-fungal proteins appears to still be inefficient due to bottlenecks in fungal expression and secretion machinery. After a brief overview of the different heterologous expression systems currently available, this review focuses on the filamentous fungi belonging to the genus Aspergillus and their use in recombinant protein production. We describe key steps in protein synthesis and secretion that may limit production efficiency in Aspergillus systems and present genetic engineering approaches and bioprocessing strategies that have been adopted in order to improve recombinant protein titers and expand the potential of Aspergilli as competitive production platforms.

Lovastatin producing by wild strain of Aspergillus terreus isolated from Brazil

Lovastatin is a drug in the statin class which acts as a natural inhibitor of 3-hydroxy-3-methylglutaryl, a coenzyme reductase reported as being a potential therapeutic agent for several diseases: Alzheimer's, multiple sclerosis, osteoporosis and due to its anti-cancer properties. Aspergillus terreus is known for producing a cholesterol reducing drug. This study sets out to evaluate the production of lovastatin by Brazilian wild strains of A. terreus isolated from a biological sample and natural sources. Carbon and nitrogen sources and the best physicochemical conditions using factorial design were also evaluated. The 37 fungal were grown to produce lovastatin by submerged fermentation. A. terreus URM5579 strain was the best lovastatin producer with a level of 13.96 mg/L. Soluble starch and soybean flour were found to be the most suitable substrates for producing lovastatin (41.23 mg/L) and biomass (6.1 mg/mL). The most favorable production conditions were found in run 16 with 60 g/L soluble starch, 15 g/L soybean flour, pH 7.5, 200 rpm and maintaining the solution at 32 °C for 7 days, which led to producing 100.86 mg/L of lovastatin and 17.68 mg/mL of biomass. Using natural strains and economically viable substrates helps to optimize the production of lovastatin and promote its use.

Fungal statin pump protein improves monacolin J efflux and regulates its production in Komagataella phaffii

Background

Monacolin J (MJ) is a key intermediate for the synthesis of cholesterol-lowering drug simvastatin. Current industrial production of MJ involves complicated chemical hydrolysis of microbial fermented lovastatin. Recently, heterologous production of MJ has been achieved in yeast and bacteria, but the resulting metabolic stress and excessive accumulation of the compound adversely affect cell activity.

Results

Five genes, tapA, stapA, slovI, smokI and smlcE, coding for fungal statin pump proteins were expressed in an MJ producing yeast strain, Komagataella phaffii J#9. Overexpression of these genes facilitated MJ production. Among them, tapA from Aspergillus terreus highly improved MJ production and led to a titer increase of 108%. Exogenous MJ feeding study on an MJ non-producing strain GS-PGAP-TapA was then performed, and the results illustrated tough entry of MJ into cells and possible efflux action of TapA. Further, intracellular and extracellular MJ levels of J#9 and J#9-TapA were analyzed. The extracellular MJ level of J#9-TapA increased faster, but its intracellular MJ percentage kept lower as compared to J#9. The results proved that TapA effectively excreted MJ from cells. Then functions of TapA were evaluated in a high-production bioreactor fermentation. Differently, TapA expression caused a low MJ titer but high intracellular MJ accumulation in J#9-TapA compared with J#9.

Conclusions

Statin pump proteins improved MJ production in K. phaffii in a shake flask. Exogenous MJ feeding and endogenous MJ producing experiments demonstrated the efflux function of TapA. TapA improved MJ production at low MJ levels in a shake flask, but decreased it at high MJ levels in a bioreactor. This finding is useful for statin pump improvement and metabolic engineering for statin bioproduction.

Effects of methyl oleate and microparticle-enhanced cultivation on echinocandin B fermentation titer

Echinocandin B (ECB) is a key precursor of antifungal agent Anidulafungin, which has demonstrated clinical efficacy in patients with invasive candidiasis. In this study, the effects of microparticle-enhanced cultivation and methyl oleate on echinocandin B fermentation titer were investigated. The results showed that the titer was significantly influenced by the morphological type of mycelium, and mycelium pellet was beneficial to improve the titer of this secondary metabolism. First, different carbon sources were chosen for the fermentation, and methyl oleate achieved the highest echinocandin B titer of 2133 ± 50 mg/L, which was two times higher than that of the mannitol. The study further investigated the metabolic process of the fermentation, and the results showed that L-threonine concentration inside the cell could reach 275 mg/L at 168 h with methyl oleate, about 2.5 times higher than that of the mannitol. Therefore, L-threonine may be a key precursor of echinocandin B. In the end, a new method of adding microparticles for improving the mycelial morphology was used, and the addition of talcum powder (20 g/L, diameter of 45 µm) could make the maximum titer of echinocandin B reach 3148 ± 100 mg/L.

Growing a circular economy with fungal biotechnology: a white paper

Fungi have the ability to transform organic materials into a rich and diverse set of useful products and provide distinct opportunities for tackling the urgent challenges before all humans. Fungal biotechnology can advance the transition from our petroleum-based economy into a bio-based circular economy and has the ability to sustainably produce resilient sources of food, feed, chemicals, fuels, textiles, and materials for construction, automotive and transportation industries, for furniture and beyond. Fungal biotechnology offers solutions for securing, stabilizing and enhancing the food supply for a growing human population, while simultaneously lowering greenhouse gas emissions. Fungal biotechnology has, thus, the potential to make a significant contribution to climate change mitigation and meeting the United Nation’s sustainable development goals through the rational improvement of new and established fungal cell factories. The White Paper presented here is the result of the 2nd Think Tank meeting held by the EUROFUNG consortium in Berlin in October 2019. This paper highlights discussions on current opportunities and research challenges in fungal biotechnology and aims to inform scientists, educators, the general public, industrial stakeholders and policymakers about the current fungal biotech revolution.

Synthetic Approaches Towards Antihypercholesterolemic Drug Simvastatin

Cardiovascular diseases are among the most threatening problems being faced by twenty-first century humans. The core cause of these diseases is high cholesterol level. Simvastatin (1: Synvinolin) is a well-known cholesterol-lowering drug marketed under the trade name Zocor®, which significantly reduces the risk of cardiovascular diseases related to hypercholesterolemia and is effective in lowering the total plasma cholesterol, low-density and very low-density lipoprotein cholesterol. It also enhances the high-density lipoprotein cholesterol. This review article aims to provide an overview of several chemical and biological methods utilized for the production of simvastatin in high yields and purity. Many robust and scalable methods have been described using lovastatin (2: Mevinolin) as a starting material, produced by the fungal strain of Aspergelius terreus. Enzymatic synthesis of simvastatin is also highlighted in this review. In addition, detailed experimental conditions, as well as the compatibility for industrial-scale preparations of simvastatin are also discussed.

Penicillin and cephalosporin biosyntheses are also regulated by reactive oxygen species

In an earlier work on lovastatin production by Aspergillus terreus, we found that reactive oxygen species (ROS) concentration increased to high levels precisely at the start of the production phase (idiophase) and that these levels were sustained during all idiophase. Moreover, it was shown that ROS regulate lovastatin biosynthesis. ROS regulation has also been reported for aflatoxins. It has been suggested that, due to their antioxidant activity, aflatoxins are regulated and synthesized like a second line of defense against oxidative stress. To study the possible ROS regulation of other industrially important secondary metabolites, we analyzed the relationship between ROS and penicillin biosynthesis by Penicillium chrysogenum and cephalosporin biosynthesis by Acremonium chrysogenum. Results revealed a similar ROS accumulation in idiophase in penicillin and cephalosporin fermentations. Moreover, when intracellular ROS concentrations were decreased by the addition of antioxidants to the cultures, penicillin and cephalosporin production were drastically reduced. When intracellular ROS were increased by the addition of exogenous ROS (H₂O₂) to the cultures, proportional increments in penicillin and cephalosporin biosyntheses were obtained. It was also shown that lovastatin, penicillin, and cephalosporin are not antioxidants. Taken together, our results provide evidence that ROS regulation is a general mechanism controlling secondary metabolism in fungi.

Biotechnological Production of Statins: Metabolic Aspects and Genetic Approaches

Statins are drugs used for people with abnormal lipid levels (hyperlipidemia) and are among the best-selling medications in the United States. Thus, the aspects related to the production of these drugs are of extreme importance for the pharmaceutical industry. Herein, we provide a non-exhaustive review of fungal species used to produce statin and highlighted the major factors affecting the efficacy of this process. The current biotechnological approaches and the advances of a metabolic engineer to improve statins production are also emphasized. The biotechnological production of the main statins (lovastatin, pravastatin and simvastatin) uses different species of filamentous fungi, for example Aspergillus terreus. The statins production is influenced by different types of nutrients available in the medium such as the carbon and nitrogen sources, and several researches have focused their efforts to find the optimal cultivation conditions. Enzymes belonging to Lov class, play essential roles in statin production and have been targeted to genetic manipulations in order to improve the efficiency for Lovastatin and Simvastatin production. For instance, Escherichia coli strains expressing the LovD have been successfully used for lovastatin production. Other examples include the use of iRNA targeting LovF of A. terreus. Therefore, fungi are important allies in the fight against hyperlipidemias. Although many studies have been conducted, investigations on bioprocess optimization (using both native or genetic- modified strains) still necessary.

Quality and Authenticity Control of Functional Red Yeast Rice-A Review

Red yeast rice (RYR) is made by fermenting the rice with Monascus. It is commonly used in food colorants, dyeing, and wine making in China and its neighboring countries. Nowadays RYR has two forms on the market: common RYR is used for food products, the other form is functional RYR for medicine. However, some researchers reported that commercial lovastatin (structure is consistent with monacolin K) is illegally added to common RYR to meet drug quality standards, so as to imitate functional RYR and sell the imitation at a higher price. Based on current detection methods, it is impossible to accurately distinguish whether functional RYR is adulterated. Therefore, it is especially important to find a way to authenticate functional RYR. In the current review, the advances in history, applications, components (especially monacolins, monacolins detection methods), quality standards, authentication methods and perspectives for the future study of RYR are systematically reviewed.

Comparative Transcriptome Analysis Shows Conserved Metabolic Regulation during Production of Secondary Metabolites in Filamentous Fungi

Filamentous fungi possess great potential as sources of medicinal bioactive compounds, such as antibiotics, but efficient production is hampered by a limited understanding of how their metabolism is regulated. We investigated the metabolism of six secondary metabolite-producing fungi of the Penicillium genus during nutrient depletion in the stationary phase of batch fermentations and assessed conserved metabolic responses across species using genome-wide transcriptional profiling. A coexpression analysis revealed that expression of biosynthetic genes correlates with expression of genes associated with pathways responsible for the generation of precursor metabolites for secondary metabolism. Our results highlight the main metabolic routes for the supply of precursors for secondary metabolism and suggest that the regulation of fungal metabolism is tailored to meet the demands for secondary metabolite production. These findings can aid in identifying fungal species that are optimized for the production of specific secondary metabolites and in designing metabolic engineering strategies to develop high-yielding fungal cell factories for production of secondary metabolites. IMPORTANCE Secondary metabolites are a major source of pharmaceuticals, especially antibiotics. However, the development of efficient processes of production of secondary metabolites has proved troublesome due to a limited understanding of the metabolic regulations governing secondary metabolism. By analyzing the conservation in gene expression across secondary metabolite-producing fungal species, we identified a metabolic signature that links primary and secondary metabolism and that demonstrates that fungal metabolism is tailored for the efficient production of secondary metabolites. The insight that we provide can be used to develop high-yielding fungal cell factories that are optimized for the production of specific secondary metabolites of pharmaceutical interest.

Improved lovastatin production by inhibiting (+)-geodin biosynthesis in Aspergillus terreus

Lovastatin is widely prescribed to reduce elevated levels of cholesterol and prevent heart-related diseases. Cultivation of Aspergillus terreus (ATCC 20542) with carbohydrates or low-value feedstocks such as glycerol produces lovastatin as a secondary metabolite and (+)-geodin as a by-product. An A. terreus mutant strain was developed (gedCΔ) with a disrupted (+)-geodin biosynthesis pathway. The gedCΔ mutant was created by inserting the antibiotic marker hygromycin B (hyg) within the gedC gene that encodes emodin anthrone polyketide synthase (PKS), a primary gene responsible for initiating (+)-geodin biosynthesis. The effects of emodin anthrone PKS gene disruption on (+)-geodin and lovastatin biosynthesis and the production of the precursors acetyl-CoA and malonyl-CoA were investigated with cultures based on glycerol alone and in combination with lactose. The gedCΔ strain showed improved lovastatin production, particularly when cultivated on the glycerol-lactose mixture, increasing lovastatin production by 80% (113 mg/L) while simultaneously inhibiting (+)-geodin biosynthesis compared to the wild-type strain. This study thus shows that suppression of the (+)-geodin pathway increases lovastatin yield and demonstrates a practical approach of manipulating carbon flux by modulating enzyme activity.

Biocatalyzed Synthesis of Statins: A Sustainable Strategy for the Preparation of Valuable Drugs

Statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, are the largest selling class of drugs prescribed for the pharmacological treatment of hypercholesterolemia and dyslipidaemia. Statins also possess other therapeutic effects, called pleiotropic, because the blockade of the conversion of HMG-CoA to (R)-mevalonate produces a concomitant inhibition of the biosynthesis of numerous isoprenoid metabolites (e.g., geranylgeranyl pyrophosphate (GGPP) or farnesyl pyrophosphate (FPP)). Thus, the prenylation of several cell signalling proteins (small GTPase family members: Ras, Rac, and Rho) is hampered, so that these molecular switches, controlling multiple pathways and cell functions (maintenance of cell shape, motility, factor secretion, differentiation, and proliferation) are regulated, leading to beneficial effects in cardiovascular health, regulation of the immune system, anti-inflammatory and immunosuppressive properties, prevention and treatment of sepsis, treatment of autoimmune diseases, osteoporosis, kidney and neurological disorders, or even in cancer therapy. Thus, there is a growing interest in developing more sustainable protocols for preparation of statins, and the introduction of biocatalyzed steps into the synthetic pathways is highly advantageous—synthetic routes are conducted under mild reaction conditions, at ambient temperature, and can use water as a reaction medium in many cases. Furthermore, their high selectivity avoids the need for functional group activation and protection/deprotection steps usually required in traditional organic synthesis. Therefore, biocatalysis provides shorter processes, produces less waste, and reduces manufacturing costs and environmental impact. In this review, we will comment on the pleiotropic effects of statins and will illustrate some biotransformations nowadays implemented for statin synthesis.

Biological and chemical diversity go hand in hand: Basidiomycota as source of new pharmaceuticals and agrochemicals

The Basidiomycota constitutes the second largest higher taxonomic group of the Fungi after the Ascomycota and comprises over 30.000 species. Mycelial cultures of Basidiomycota have already been studied since the 1950s for production of antibiotics and other beneficial secondary metabolites. Despite the fact that unique and selective compounds like pleuromutilin were obtained early on, it took several decades more until they were subjected to a systematic screening for antimicrobial and anticancer activities. These efforts led to the discovery of the strobilurins and several hundreds of further compounds that mainly constitute terpenoids. In parallel the traditional medicinal mushrooms of Asia were also studied intensively for metabolite production, aimed at finding new therapeutic agents for treatment of various diseases including metabolic disorders and the central nervous system. While the evaluation of this organism group has in general been more tedious as compared to the Ascomycota, the chances to discover new metabolites and to develop them further to candidates for drugs, agrochemicals and other products for the Life Science industry have substantially increased over the past decade. This is owing to the revolutionary developments in -OMICS techniques, bioinformatics, analytical chemistry and biotechnological process technology, which are steadily being developed further. On the other hand, the new developments in polythetic fungal taxonomy now also allow a more concise selection of previously untapped organisms. The current review is dedicated to summarize the state of the art and to give an outlook to further developments.

Engineering Saccharomyces cerevisiae for production of simvastatin

Simvastatin is a semisynthetic cholesterol-lowering medication and one of the top-selling statins in the world. Currently, industrial production of simvastatin acid (SVA) is a multistep process starting from the natural product lovastatin. For this reason, there is significant interest in direct production of simvastatin from a microbial host. In this study, six heterologous biosynthetic genes were introduced into Saccharomyces cerevisiae and the acyl-donor dimethylbutyryl-S-methyl mercaptopropionate (DMB-SMMP) was added, resulting in initial production of 0.5 mg/L SVA. Switching the yeast strain from JHY686 to BJ5464-NpgA increased total polyketide production to over 60 mg/L and conversion from dihydromonacolin L acid to monacolin J acid (MJA) was increased from 60% to 90% by tuning the copy number of the P450 lovA. Increasing the media pH to 8.7 led to a further 10-fold increase in SVA production. Optimized chemical lysis of the cell walls in situ after maximum MJA production led to 55 mg/L SVA titer, representing nearly complete conversion from MJA and a 110-fold increase in titer from the initial SVA production strain. The yeast strains developed in this work can be used as an alternative production method for SVA, and the strategies employed can be broadly applied for heterologous production of other fungal polyketides and semisynthetic compounds in yeast.

iTRAQ-Based Quantitative Proteomic Analysis Reveals Changes in Metabolite Biosynthesis in Monascus purpureus in Response to a Low-Frequency Magnetic Field

Background: Low-frequency magnetic fields (LF-MFs) dampen the citrinin output by Monascus purpureus in fermentations. The influence of LF-MFs on biosynthesis by M. purpureus was evaluated at the protein level. Methods: Cultures were treated with a 1.6-mT MF from day 0 to day 2 of incubation, and secondary metabolite production was evaluated on the day 12 of incubation. All proteins were extracted from M. purpureus mycelia and subjected to isobaric tags for relative and absolute quantification (iTRAQ) labeling and subsequent liquid chromatography/mass spectrometry (LC-MS/MS) analysis on day 6 of fermentation. Results: There was no difference in biomass between the treated samples and the control. Citrinin production was 46.7% lower, and the yields of monacolin K and yellow, orange, and red pigment were 29.3%, 31.3%, 41.7%, and 40.3% higher, respectively, in the exposed samples compared to the control. Protein expression in M. purpureus under LF-MF treatment was quantified using iTRAQ technology. Of 2031 detected proteins, 205 were differentially expressed. The differentially-expressed proteins were subjected to Gene Ontology (GO) functional annotation and statistical analysis, which revealed that they mainly refer to biological metabolism, translation, antioxidant, transport and defense pathways. Among all the tagged proteins, emphasis was placed on the analysis of those involved in the synthesis of citrinin, pigment and monacolin K was emphasized. Conclusions: LF-MFs affected Monascus secondary metabolism at the protein level, and aggregate data for all the protein profiles in LF-MF-treated Monascus was obtained.

Bioprospecting lovastatin production from a novel producer Cunninghamella blakesleeana

Beside anti-cholesterol activity, lovastatin garners worldwide attention for therapeutical application against various diseases especially cancer. A total of 36 filamentous fungi from soil samples were isolated and screened for lovastatin production by yeast growth bioassay method. C9 strain (later identified as Cunninghamella blakesleeana) was screened as potential strain of lovastatin production. Further confirmation of the compound was made using TLC, HPTLC and HPLC in which similar Rf value, densitogram peak and chromatogram peak against the standard lovastatin were observed, respectively. The purified lovastatin subjected for IR analysis showed a lactone ring peak at 1763.63 cm-1 similar to standard lovastatin. Further structural analysis including NMR and LC-MS of the purified lovastatin reassures the molecular formula and molecular weight similar to standard. In quantitative terms, C. blakesleeana, Aspergillus terreus and Aspergillus flavus produced 1.4 mg g-1 DWS, 0.83 mg g-1 DWS and 0.3 mg g-1 DWS of lovastatin, respectively, (p < 0.0001) without any optimization. Lovastatin showed significant antioxidant property with IC50: 145.9 µg mL-1 (140 µL), and the percentage of inhibition is maximum at 199.5 µg/mL which is statistically significant (p < 0.0001).