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1.
The influence of various combinations of glycerol and lactose feed on the biosynthesis of two polyketide metabolites, lovastatin and (+)-geodin, by Aspergillus terreus ATCC20542 in a discontinuous fed-batch culture was presented. In these experiments lactose and/or glycerol were also used as the initial carbon substrates in the cultivation media. The application of glycerol feed, when lactose is the initial substrate, leads to the appreciable lovastatin concentration in the broth (122.4 mg l−1), nevertheless the abundant (+)-geodin level is at the same time obtained (255.5 mg l−1). The cultures with glycerol as the initial substrate and fed with lactose produce less lovastatin and (+)-geodin. The application of the various combined glycerol and/or lactose feeds allows for improving lovastatin production up to 161.8 mg l−1 and decreases (+)-geodin concentration to 98.7 mg l−1. The analysis of product formation rates and yield coefficients indicates that lovastatin is more efficiently produced on lactose, especially in the initial stages of the cultivation. Glycerol efficiently sustains fungal activity to form these polyketides in the late idiophase but it mainly favours (+)-geodin formation, if solely used in the feed. The feeds performed both with lactose and glycerol occur to be the most desired to maximise lovastatin and minimise (+)-geodin formation. 相似文献
2.
《Biochemical Engineering Journal》2009,43(3):198-207
The simultaneous formation of mevinolinic acid (lovastatin; antihypercholesterolemia drug) and (+)-geodin (by-product) by Aspergillus terreus ATCC 20542 in the batch and fed-batch cultivation in the stirred tank bioreactor was investigated and described in this paper. The main factors influencing the formation of these two secondary metabolites were the initial nitrogen concentration and the aeration rate of the medium. The experiments aimed at achieving as high as possible lovastatin titre accompanied by as low as possible (+)-geodin concentration. The application of lactose-fed discontinuous fed-batch process allowed increasing lovastatin formation, in comparison with the batch process. Nevertheless (+)-geodin titre increased too. But the control of pH at the levels of 7.6 and 7.8 was successfully applied to repress the formation of the by-product both in batch and fed-batch experiments. Additionally, apart from pH control, the supplementation of the medium with nicotinamide and calcium pantothenate was used to facilitate the formation of lovastatin. The simultaneous pH control and B-group vitamin supplementation allowed achieving the best results in the batch cultivation. 相似文献
3.
The influence of initial glycerol and lactose concentrations on lovastatin and (+)‐geodin formation in batch cultures of Aspergillus terreus ATCC 20542 was presented. At first the experiments comprised lovastatin biosynthesis on glycerol as the sole carbon source. Lovastatin titers below 40 mg/L were found under these conditions and they were lower than previously obtained results when lactose was used as the sole carbon source. However, the application of the mixture of glycerol and lactose allowed in achieving higher lovastatin concentration in the broth. It even exceeded 122 mg/L when 10 g lactose and 15 g glycerol per liter were used. The calculated lovastatin volumetric and specific formation rates on glycerol or lactose and on the mixture of these two showed that lovastatin was faster produced on lactose than on glycerol. In the trophophase, the maximum volumetric lovastatin formation rate on lactose was up to four times higher than on glycerol and so was the lovastatin specific formation rate. Similar relations for the accompanying (+)‐geodin biosynthesis were also studied. When the mixture of lactose and glycerol was used, the transformation of (+)‐geodin to other polyketide metabolites also took place. 相似文献
4.
The influence of the morphology and differentiation of Aspergillus terreus hyphae on the formation of mevinolinic acid (lovastatin) and (+)-geodin was tested. Lovastatin titre was the highest (above
60 mg l−1) in the system with smaller pellets (diameter below 1.5 mm) and high biomass concentration (above 10 g l−1 in the idiophase). These biomass features were induced by the higher initial number of spores in the preculture (above 2 × 1010 l−1). At the initial number of spores below 2 × 109 l−1 (+)-geodin biosynthesis was the most efficient but it was rather connected with the elevated C/N ratio than with the pellet
size. In order to quantify the hyphal differentiation in fungal pellets a special approach was used. The sectioning of the
stained pellets together with the image analysis and calculation procedures were applied. The analysis of hyphal differentiation
indicated that lovastatin formation was correlated with the fraction of the active, growing hyphae. 相似文献
5.
Integrating transcriptional and metabolite profiles to direct the engineering of lovastatin-producing fungal strains 总被引:17,自引:0,他引:17
Askenazi M Driggers EM Holtzman DA Norman TC Iverson S Zimmer DP Boers ME Blomquist PR Martinez EJ Monreal AW Feibelman TP Mayorga ME Maxon ME Sykes K Tobin JV Cordero E Salama SR Trueheart J Royer JC Madden KT 《Nature biotechnology》2003,21(2):150-156
6.
The simultaneous biosynthesis of lovastatin (mevinolinic acid) and (+)-geodin by Aspergillus terreus ATCC 20542 with regard to the medium composition, i.e. the concentrations of carbon and nitrogen source, was described in this paper. A. terreus is a lovastatin producer but the formation of lovastatin was accompanied by the significant amounts of (+)-geodin, when the elevated concentration of carbon source (lactose) was still present in the medium in the idiophase and nitrogen source (yeast extract) was deficient. It was observed for runs, in which the higher (above 20 g l(-1)) initial lactose concentration was applied or when the nitrogen deficiency led to the decrease of biomass content in the system. In contrast to lovastatin, there was not optimum initial concentration of yeast extract, as its lowest tested initial concentration (2 g l(-1)) led to the highest (+)-geodin volumetric formation rates and final yield. What is more, even higher final (+)-geodin concentrations were achieved at elevated initial lactose concentration (40 g l(-1)) and in the lactose-fed fed-batch run. In the fed-batch run lovastatin concentration increased significantly too, as this metabolite formation is also carbon source dependent. Finally, (+)-geodin occurred to be a metabolite, whose formation, in contrast to lovastatin, is non-growth associated. 相似文献
7.
【目的】分析洛伐他汀工业生产菌株土曲霉HZ01的次级代谢产物合成能力,为后期的遗传改造、次级代谢产物及其基因簇挖掘提供指导。【方法】对洛伐他汀发酵条件下的样品进行了转录组分析,同时运用色谱分离技术及波谱学方法对主要次级代谢产物进行了分离和结构鉴定。【结果】洛伐他汀合成相关基因转录水平非常高,还有4个聚酮合酶(PKS)、6个非核糖体多肽合成酶(NRPS)和1个PKS-NRPS杂合酶基因进行了转录,其他PKS和NRPS基因都处于沉默状态。此外,从该菌的发酵产物中分离鉴定了10个主要副产物并确定了其结构。【结论】土曲霉HZ01是一株优良的洛伐他汀生产菌株,在构建次级代谢产物异源合成细胞工厂和鉴定次级代谢产物生物合成途径方面具有很好的应用潜力。 相似文献
8.
Biotechnological production and applications of statins 总被引:1,自引:0,他引:1
Javier Barrios-González Roxana U. Miranda 《Applied microbiology and biotechnology》2010,85(4):869-883
Statins are a group of extremely successful drugs that lower cholesterol levels in blood; decreasing the risk of heath attack
or stroke. In recent years, statins have also been reported to have other biological activities and numerous potential therapeutic
uses. Natural statins are lovastatin and compactin, while pravastatin is derived from the latter by biotransformation. Simvastatin,
the second leading statin in the market, is a lovastatin semisynthetic derivative. Lovastatin is mainly produced by Aspergillus terreus strains, and compactin by Penicillium citrinum. Lovastatin and compactin are produced industrially by liquid submerged fermentation, but can also be produced by the emerging
technology of solid-state fermentation, that displays some advantages. Advances in the biochemistry and genetics of lovastatin
have allowed the development of new methods for the production of simvastatin. This lovastatin derivative can be efficiently
synthesized from monacolin J (lovastatin without the side chain) by a process that uses the Aspergillus terreus enzyme acyltransferase LovD. In a different approach, A. terreus was engineered, using combinational biosynthesis on gene lovF, so that the resulting hybrid polyketide synthase is able to in vivo synthesize 2,2-dimethylbutyrate (the side chain of simvastatin).
The resulting transformant strains can produce simvastatin (instead of lovastatin) by direct fermentation. 相似文献
9.
Adding talc microparticles to Aspergillus terreus ATCC 20542 preculture decreases fungal pellet size and improves lovastatin production
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Changing fungal morphology with the use of morphological engineering techniques leads to improving the production of metabolites by filamentous fungi in the submerged culture. Adding mineral microparticles is one such simple method to change fungal pellet size. Here, it was studied for a lovastatin producer, Aspergillus terreus ATCC 20542. The experiments were conducted in shake flasks and 10 μm talc microparticles were added to the preculture. Intrapellet oxygen concentration profiles were determined by an oxygen microprobe. Talc microparticles caused a decrease of A. terreus pellets diameter from about 2000 to 900 μm, dependent on their concentration in the preculture. Smaller pellets produced more lovastatin, whose titre exceeded then 120 mg L?1, utilising more lactose. The decrease in pellet size resulted in changes of oxygen concentration profiles in the pellets. The estimated critical pellet diameter, at which the non‐oxygenated zone was observed in the centre of the pellets, was 1700 μm. Smaller pellets were fully penetrated by oxygen. To conclude, facilitated diffusion of oxygen into the pellets of smaller diameter and their less dense structure made lactose utilisation by A. terreus more efficient, which ultimately increased lovastatin production in the runs with talc microparticles added, compared to the control runs. 相似文献
10.
Aspects of the biosynthesis of non-aromatic fungal polyketides by iterative polyketide synthases 总被引:11,自引:0,他引:11
Hutchinson CR Kennedy J Park C Kendrew S Auclair K Vederas J 《Antonie van Leeuwenhoek》2000,78(3-4):287-295
Lovastatin biosynthesis in Aspergillus terreus involves two unusual type I multifunctional polyketide syntheses (PKSs). Lovastatin nonaketide synthase (LNKS), the product of the lovB gene, is an iterative PKS that interacts with LovC, a putative enoyl reductase, to catalyze the 35 separate reactions in the biosynthesis of dihydromonacolin L, a lovastatin precursor. LNKS also displays Diels-Alderase activity in vitro. Lovastatin diketide synthase (LDKS) made by lovF, in contrast, acts non-iteratively like the bacterial modular PKSs to make (2R)-2–methylbutyric acid. Then, like LNKS, LDKS interacts closely with another protein, the LovD transesterase enzyme that catalyzes attachment of the 2–methylbutyric acid to monacolin J in the final step of the lovastatin pathway. Key features of the genes for these four enzymes and others, plus the regulatory and self-resistance factors involved in lovastatin production, are also described. 相似文献
11.
Lovastatin Biosynthesis by Aspergillus terreus in a Chemically Defined Medium 总被引:2,自引:0,他引:2
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Lovastatin is a secondary metabolite produced by Aspergillus terreus. A chemically defined medium was developed in order to investigate the influence of carbon and nitrogen sources on lovastatin biosynthesis. Among several organic and inorganic defined nitrogen sources metabolized by A. terreus, glutamate and histidine gave the highest lovastatin biosynthesis level. For cultures on glucose and glutamate, lovastatin synthesis initiated when glucose consumption levelled off. When A. terreus was grown on lactose, lovastatin production initiated in the presence of residual lactose. Experimental results showed that carbon source starvation is required in addition to relief of glucose repression, while glutamate did not repress biosynthesis. A threefold-higher specific productivity was found with the defined medium on glucose and glutamate, compared to growth on complex medium with glucose, peptonized milk, and yeast extract. 相似文献
12.
13.
Aspergillus terreus is a textbook example of an industrially relevant filamentous fungus. It is used for the biotechnological production of two valuable metabolites, namely itaconic acid and lovastatin. Itaconic acid serves as a precursor in polymer industry, whereas lovastatin found its place in the pharmaceutical market as a cholesterol-lowering statin drug and a precursor for semisynthetic statins. Interestingly, their biosynthetic gene clusters were shown to reside in the common genetic neighborhood. Despite the genomic proximity of the underlying biosynthetic genes, the production of lovastatin and itaconic acid was shown to be favored by different factors, especially with respect to pH values of the broth. While there are several reviews on various aspects of lovastatin and itaconic acid production, the survey on growth conditions, biochemistry and morphology related to the formation of these two metabolites has never been presented in the comparative manner. The aim of the current review is to outline the correlations and contrasts with respect to process-related and biochemical discoveries regarding itaconic acid and lovastatin production by A. terreus. 相似文献
14.
15.
Muhamad Hafiz Abd Rahim Hanan Hasan Alejandro Montoya Ali Abbas 《Engineering in Life Science》2015,15(2):220-228
The use of pure substrate represents a significant proportion of the cost of manufacturing a drug such as lovastatin. This study explores the production of lovastatin and (+)‐geodin by Aspergillus terreus ATCC 20542 using biodiesel‐derived crude glycerol (CG) as a feedstock. Shake flask experiments showed reduced lovastatin production and glycerol consumption in the presence of 10–50 g/L CG with respect to pure glycerol controls. At 50 g/L, lovastatin and (+)‐geodin production was significantly reduced by 82 and 73%, respectively. The lowest lovastatin inhibition was detected in 30 g/L of CG (48%), which was accompanied by a significant rise in (+)‐geodin production (338%). Further investigation was performed on three major impurities found in CG, namely methanol (MeOH), sodium chloride (NaCl), and fatty acids (oleic acid and palmitic acid (PA), soap). None was particularly inhibitory for lovastatin, except soap and PAs, which reduced its production by more than 50% at all concentrations tested. In contrast, (+)‐geodin was inhibited in the presence of MeOH and PA by up to 46 and 91%, respectively. These observations indicate that partial purification of CG would be potentially useful in improving production of lovastatin and (+)‐geodin by A. terreus. 相似文献
16.
Eiichiro Kan Yohei Katsuyama Jun-ichi Maruyama Koichi Tamano Yasuji Koyama 《Bioscience, biotechnology, and biochemistry》2019,83(7):1372-1381
The filamentous fungus Aspergillus oryzae was recently used as a heterologous host for fungal secondary metabolite production. Here, we aimed to produce the plant polyketide curcumin in A. oryzae. Curcumin is synthesized from feruloyl-coenzyme A (CoA) and malonyl-CoA by curcuminoid synthase (CUS). A. oryzae expressing CUS produced curcumin (64 μg/plate) on an agar medium containing feruloyl-N-acetylcysteamine (a feruloyl-CoA analog). To increase curcumin yield, we attempted to strengthen the supply of malonyl-CoA using two approaches: enhancement of the reaction catalyzed by acetyl-CoA carboxylase (ACC), which produces malonyl-CoA from acetyl-CoA, and inactivation of the acetyl-CoA-consuming sterol biosynthesis pathway. Finally, we succeeded in increasing curcumin yield sixfold by the double disruption of snfA and SCAP; SnfA is a homolog of SNF1, which inhibits ACC activity by phosphorylation in Saccharomyces cerevisiae and SCAP is positively related to sterol biosynthesis in Aspergillus terreus. This study provided useful information for heterologous polyketide production in A. oryzae. 相似文献
17.
Biosynthesis of metabolites and enzymes by filamentous fungi depends on their morphological form in submerged cultures. However, their early stages of growth lasting approximately 24 h, from the introduction of spores to the medium until the formation of stable morphological forms, such as clumps or pellets, have rarely been the objects of experimental and modeling studies. Microparticle‐enhanced cultivation (MPEC) has been applied only to a few fungal species, mainly Aspergilli. Therefore, the objective of this work was to formulate the kinetic model to describe the early stages of the fungal evolution in the standard cultivation and MPEC for Aspergillus terreus, Chaetomium globosum, Penicillium rubens, and Mucor racemosus. These fungi exhibit various mechanisms of agglomerates formation in submerged cultures. The experiments were performed in batch shake flasks (parameters identification) and a stirred tank bioreactor (model verification). In the balance equation for fungal cells, the mean projected area of hyphal objects measured by the digital analysis of microscopic images was used as the dependent variable. The analysis of the experimental data and model solution revealed that the effect of the microparticles (aluminum oxide at 6 g L?1) in MPEC toward the studied filamentous fungi was to the high extent species dependent. This effect was most evident in the case of spore coagulative A. terreus and noncoagulative M. racemosus. 相似文献
18.
19.
New strategies for improving the fermentation yield of (+)-terrein which is a fungal metabolite with multiple bioactivities are very urgent. In this study, the effect of suberoylanilide hydroxamic acid, one kind of epigenetic modifier, on the biosynthesis of (+)-terrein by Aspergillus terreus strain PF26 isolated from the marine sponge Phakellia fusca was investigated. It was found that suberoylanilide hydroxamic acid exhibited a positive impact on (+)-terrein production, resulting from promoting the biosynthesis of 6-hydroxymellein, the precursor of (+)-terrein. Through optimization of feeding concentration and time of suberoylanilide hydroxamic acid, 5.58 g/L (+)-terrein could be obtained in shake flask cultivation, 29.5% higher than the control. Correspondingly, the fermentation of A. terreus strain PF26 in 7.5-L stirred bioreactor with feeding suberoylanilide hydroxamic acid (900 μM, day 4) yielded 9.07 g/L (+)-terrein, 77.1% higher than the control. These results showed that the epigenetic modifier-suberoylanilide hydroxamic acid could be utilized to enhance the production of (+)-terrein, which laid the foundation of massive production of (+)-terrein by fermentation. 相似文献
20.
Emodin O-methyltransferase, an enzyme catalyzing methylation of the 8-hydroxy group of emodin, was identified in the mould Aspergillus terreus IMI 16043, a (+)-geodin producing strain. The enzyme catalyzed the formation of questin from emodin and S-adenosyl-l-methionine. By chromatography on DEAE-cellulose, Phenyl Sepharose, Q-Sepharose, Hydroxyapatite, and CM-cellulose, emodin O-methyltransferase was purified to apparent homogeneity. The purified protein had a molecular weight of 322 kDa as estimated by gel filtration and 53.6 kDa as estimated by gel electrophoresis under denaturing conditions, suggesting that the active enzyme was a homohexamer. The enzyme showed pI 4.4 and optimum pH 7–8. Magnesium ion or manganese ion was not an absolute requirement, nor increased the enzyme activity. The enzyme had strict substrate specificity and very low Km values for both emodin (3.4×10-7 M) and S-adenosyl-l-methionine (4.1×10-6 M).Abbreviations EOMT
emodin O-methyltransferase from A. terreus
- SAM
S-adenosyl-l-methionine
- PAGE
polyacrylamide gel electrophoresis 相似文献