Fermentation optimization for the production of lovastatin by Aspergillus terreus: use of response surface methodology
01 Oct 2004-Journal of Chemical Technology & Biotechnology (John Wiley & Sons, Ltd)-Vol. 79, Iss: 10, pp 1119-1126
TL;DR: A Box-Behnken experimental design was used to investigate the effects of five factors (oxygen content in the gas phase, concentrations of C, N and P, and fermentation time) on the concentrations of biomass and lovastatin produced in batch cultures of Aspergillus terreus as discussed by the authors.
Abstract: A Box-Behnken experimental design was used to investigate the effects of five factors—ie oxygen content in the gas phase; concentrations of C, N and P; and fermentation time—on the concentrations of biomass and lovastatin produced in batch cultures of Aspergillus terreus. The values of the various factors in the experiment ranged widely, as follows: 20-80% (v/v) oxygen in the aeration gas; 8-48 g dm −3 C-concentration; 0.2-0.6 g dm −3 N-concentration; 0.5-2.5 g dm −3 phosphate-concentration; and 7-11 days fermentation time. No previous work has used statistical analysis in documenting the interactions between oxygen supply and nutrient concentrations in lovastatin production. The Box-Behnken design identified the oxygen content in the gas phase as the principal factor influencing the production of lovastatin. Both a limitation and excess of oxygen reduced lovastatin titers. A medium containing 48 g dm −3 C supplied as lactose, 0.46 g dm −3 N supplied as soybean meal, and 0.79 g dm −3 phosphate supplied as KH2PO4, was shown to support high titers (∼230 mg dm −3 )o f lovastatin in a7 -day fermentation in oxygen-rich conditions (80% v/v oxygen in the aeration gas). Under these conditions, the culture medium had excess carbon but limiting amounts of nitrogen. The optimized fermentation conditions raised the lovastatin titer by four-fold compared with the worst-case scenario within the range of factors investigated. 2004 Society of Chemical Industry
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01 Jan 2011
TL;DR: In this article, various media parameters affecting the polygalacturonase (PG) production of Rhizopus oryzae, were stud ied and their relation to pellet morphology was investigated.
Abstract: Various media parameters affecting the polygalacturonase (PG) production of Rhizopus oryzae, were stud ied and their relation to pellet morphology was investigated. The basal medium in the absence of Mg +2 and in the presence of 4 mg/kg of Zn +2 at pH 3, resulted into maximum PG activity (11.53 U/ml). A composition of 14.78 g/l of glucose, 10 g/l of galactose, 5 g/l mannose, 0.5 g/l of arabinose and 19.73 g/l of xylose resulted into maximum PG activity (27.94 U/ml) when used as combined carbon sources. Corn meal as the nitrogen source, promoted PG synthesis where it resulted into 33 % more activity than corn steep liquor (CSL) and (NH 4 ) 2 SO 4 which were the next highest promoter. The highest number of pellets with an aver age mean diameter of 1.25±0.25 mm was obtained with the formulation containing (NH 4 ) 2 SO 4 and 25 g/l of glucose. Yeast extract on the other hand resulted into pellet formation with an average mean diameter of 1.75±0.25 mm at higher glucose concentration (50 g/l). The interactive effect of suitable carbon source (glucose) with suitable nitrogen source (corn meal) enhanced the PG activity 4 times more than the basal medium with pellets of 1.44±0.35mm in average diameter.
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Cites background from "Fermentation optimization for the p..."
...Therefore, this type of morphology is the desired type in many industrial fermentations such as in the production of antibiotics, organic acids and enzymes, (2)....
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31 Mar 2015
TL;DR: It is revealed that CG can potentially be used to cultivate A. terreus, provided that sufficient purification is conducted on CG and the presence of contaminants in CG could contribute to the inhibitory effect of CG on lovastatin production, with no inhibition observed on (+)-geodin and sulochrin production.
Abstract: A. terreus ATCC 20542 is a prolific fungi strain known for its ability to produce lovastatin, a potent cholesterol-lowering drug. Lovastatin is synthesised via type I polyketide pathway (PKS), a common pathway used to produce secondary metabolites in microorganisms. This pathway is also responsible for the production of two cometabolites of lovastatin, namely (+)-geodin and sulochrin. This study aimed to characterise the production of lovastatin and its co-metabolites, sulochrin and (+)geodin by A. terreus, and to investigate the relationship between lovastatin, sulochrin and (+)-geodin production using bio-waste crude glycerol (CG) as the substrate. The first part of this study investigated the effects of the major components of culture medium for the production of lovastatin, (+) -geodin and sulochrin, and pellet morphology. This investigation revealed that the types of carbon source have a major influence on lovastatin production, but not (+) -geodin and sulochrin. By contrast, the types of nitrogen source mainly influence (+)-geodin and sulochrin production. Of note, reasonable lovastatin production (25.68 mg/L), with high production of (+)-geodin (9.00 mg/L) and sulochrin (22.35 mg/L) can be achieved using glycerol as the carbon source, and yeast extract as the nitrogen source. Further, culture with glycerol produced pellets with hairy morphology, which are optimal for the production of lovastatin, (+) -geodin and sulochrin. These results provide a basis for optimum culture conditions for subsequent experiments to study the production of metabolites by A. terreus. The second part of the study investigated the potential of crude glycerol (CG), a common bio-waste product from biodiesel industry, as the substrate for A. terreus cultivation and the production of metabolites of interest. At 30 g/L of CG, the production of (+)-geodin (13.14 mg/L) and sulochrin (14.79 mg/L) increased almost 2fold, with a significant inhibition of lovastatin production (~35% reduction) when compared to pure glycerol (PG). The major contaminants from CG were then identified, and their effects on A. terreus’ growth and metabolite production were determined to further explain these observations. These studies show that the presence of contaminants in CG including saturated fatty acids (up to 48% reduction) and soap (up to 90% reduction) could contribute to the inhibitory effect of CG on lovastatin production, with no inhibition was observed on (+)-geodin and sulochrin production. Conversely, some contaminants, including double-bonded fatty acid such as oleic acid, methanol (MeOH) and salt (NaCl) could enhance lovastatin production up to 72%, with varying effects on (+)-geodin and sulochrin production. Partial purification of CG using solvent and activated carbon (AC) resulted in an improved yield of all three metabolites. This investigation revealed that CG can potentially be used to cultivate A. terreus, provided that sufficient purification is conducted on CG. Elicitor refers to a substance that provokes the microorganism’s defense system. The third part of this study investigated the effects of selected ‘elicitors’ on the production of lovastatin, (+)-geodin’s and lovastatin, and to elucidate the relationship between these three metabolites, if any. CG, which was subjected to partial purification by AC, was used for this part of the study, as the product purity was comparable to pure glycerol. In this study, the elicitors of choice were chemical elicitors such as sodium alginate, cholesterol, malonic acid, and physical elicitors such as shear force and viscosity. It was found that chemical elicitor stimulated the production of both lovastatin and sulochrin, with a lesser degree of stimulation on (+)-geodin’s production. On the other hand, (+)-geodin’s production was suppressed in the presence of high viscosity ( 500 mg/L). These observations indicate that lovastatin and sulochrin may play a role in A. terreus’ defense mechanism. Conversely, (+)-geodin may be important for fungal pellet integrity or immediate response to injury, as physical force greatly enhanced its production. In conclusion, CG is a promising alternative substrate for metabolite production by A. terreus, provided that sufficient purification and culture conditions are applied. This study, however, demonstrates no apparent relationship between the production of lovastatin, (+)-geodin and sulochrin by A. terreus using glycerol or CG as the substrate.
1 citations
Cites background from "Fermentation optimization for the p..."
...(2004) attempted to overcome this problem by controlling the dissolved gas concentration in the fermentation chamber of shaking flasks using an enriched oxygen atmosphere while maintaining the sterility [29]....
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TL;DR: The need for a polyphasic approach of morphological identification and genetic characterization of Aspergilli from Foeniculum vulgare is addressed and presented here in adequate detail.
Abstract: Ascomycetous fungi are found associated with a wide variety of substrates which range from fresh water to marine ecosystems, tropical to temperate forest soils and deserts, throughout the world over. These demystifying fungi exist as endophytes, pathogens and saprobes. They have been studied due to their ability to contaminate foods and feedstuffs, causing an elaboration of mycotoxins. The objectives of the study included extensive analyses of the morphological features of fungi, especially Aspergilli, which have been presented while studying them on specific mycological media. It is also an elaborate compilation of substantive macro- and micro-morphological characterization of different Aspergilli isolated from the spice Foeniculum vulgare used in India and other countries in the world. Further, a first of its kind attempt has been made to study their relative abundance and frequency of occurrence, molecular phylogeny and genetic relatedness to characterize the Aspergilli into specific sections, groups and clades. Single nucleotide polymorphism (SNP) analysis was carried out to evaluate the functional consequences of nucleotide variations, synonymous and non-synonymous mutations in the protein structure. The study resulted in a total of 3,506 Aspergillus isolates, which were obtained from seventy (70) fennel samples, representing 14 Aspergillus species. The two most frequently found species were A. niger and A. flavus with a relative abundance of 32.24 and 11.63%, respectively. The taxonomy and current placements have been reappraised with suggestions and prospects for future research from six sections namely Terrei, Flavi, Fumigati, Nidulantes, Nigri, and Versicolores. In addition, a total number of 27 isolates were studied and deposited at the National Centre for Biotechnology Information (NCBI) and five Aspergillus species have been identified and are being reported for the first time from the fennel seeds, based on partial sequence analysis of the official fungal barcode namely, Internal Transcribed Spacer (ITS) and a functional gene, beta tubulin gene locus, coupled with phenotypic characterization. SNPs for specific DNA regions have been used to identify variants in Aspergilli obtained from Indian fennel seeds for the first time. The need for a polyphasic approach of morphological identification and genetic characterization of Aspergilli from Foeniculum vulgare is addressed and presented here in adequate detail. Our current work makes extensive use of partial beta-tubulin gene sequences analyses to evaluate the association between SNPs in five Aspergillus species sections.
1 citations
Dissertation•
01 Jan 2013
Cites background from "Fermentation optimization for the p..."
...…semi-synthetic drug analogue to lovastatin, which is a fermentation product of the fungus Aspergillus terreus in presence of a carbon-rich medium (Mauro, 1993; Casas López et al., 2004) but has up to five times greater potency than lovastatin, as demonstrated in vitro (Desager and Horsmans, 1996)....
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...Casas López, J.L., Sánchez Pérez, J.A., Fernández Sevilla, J.M., Acién Fernández, F.G., Molina Grima, E., Chisti, Y., 2004....
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...The substance is a semi-synthetic drug analogue to lovastatin, which is a fermentation product of the fungus Aspergillus terreus in presence of a carbon-rich medium (Mauro, 1993; Casas López et al., 2004) but has up to five times greater potency than lovastatin, as demonstrated in vitro (Desager and Horsmans, 1996)....
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01 Dec 2008
TL;DR: The biological profile and initial chromatographic explorations of the active extracts confirm metabolic diversity in tropical fungi, which could be utilized to improve the production of metabolites useful in pharmacy and agriculture.
Abstract: Leaf litter fungi Beltraniella japonica, B. portoricensis, Beltraniopsis sp., Gliomastix murorum and MR45were cultured in two liquid mediums, Czapeck-Dox-yeast extract (CDY) and potato dextrose broth (PDB). In each case, mycelium was separated from the broth filter, and both were macerated with EtAcO, producing filtrate fungal extracts (FFE) and mycelium extract (MFE). These were evaluated by the reduction of radical 2, 2-diphenyl-1picrylhydrazyl (DPPH) assay, and by microdilution antimicrobial test against four pathogenic microorganisms. The results showed high ability to DPPH reduction in FFE of B. japonica, G. murorum, and MR45 in PDB and CDY. The highest antimicrobial activity was detected against S. aureus produced by both Beltraniella strains (200 µg) in PDB and against E. carotovora by MFE of B. japonica in CDY. In both mediums, this strain produced mellein, no other metabolite was identified from the active extracts. The biological profile and initial chromatographic explorations of the active extracts confirm metabolic diversity in our tropical fungi, which could be utilized to improve the production of metabolites useful in pharmacy and agriculture. ntimicrobial, antioxidants, tropical fungi, mellein.
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TL;DR: In this paper, a class of incomplete three level factorial designs useful for estimating the coefficients in a second degree graduating polynomial are described and the designs either meet, or approximately meet, the criterion of rotatability and for the most part can be orthogonally blocked.
Abstract: A class of incomplete three level factorial designs useful for estimating the coefficients in a second degree graduating polynomial are described. The designs either meet, or approximately meet, the criterion of rotatability and for the most part can be orthogonally blocked. A fully worked example is included.
3,194 citations
TL;DR: It was shown that mevinolin was an orally active cholesterol-lowering agent in the dog and orally administered sodium mevinolinate was an active inhibitor of cholesterol synthesis in an acute assay.
Abstract: Mevinolin, a fungal metabolite, was isolated from cultures of Aspergillus terreus. The structure and absolute configuration of mevinolini and its open acid form, mevinolinic acid, were determined by a combination of physical techniques. Mevinolin was shown to be 1,2,6,7,8,8a-hexahydro-beta, delta-dihydroxy-2,6-dimethyl-8-(2-methyl-1-oxobutoxy)-1-naphthalene-hepatanoic acid delta-lactone. Mevinolin in the hydroxy-acid form, mevinolinic acid, is a potent competitive inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase [mevalonate: NADP+ oxidoreductase (CoA-acylating), EC 1.1.1.34]; its Ki of 0.6 nM can be compared to 1.4 nM for the hydroxy acid form of the previously described related inhibitor, ML-236B (compactin, 6-demethylmevinolin). In the rat, orally administered sodium mevinolinate was an active inhibitor of cholesterol synthesis in an acute assay (50% inhibitory dose = 46 microgram/kg). Furthermore, it was shown that mevinolin was an orally active cholesterol-lowering agent in the dog. Treatment of dogs for 3 weeks with mevinolin at 8 mg/kg per day resulted in a 29.3 +/- 2.5% lowering of plasma cholesterol.
1,517 citations
903 citations
TL;DR: The experiments reported in this paper demonstrate that MG236A and ML-236B inhibit specifically 3-hydroxy-3-methylglutaryl (HMG)CoA reductase (EC 1 .I .1.34), the rate-limiting enzyme in cholesterol synthetic pathway, without affecting the rest of the enzymes involved in this pathway, and that the inhibition is competitive with respect to the substrate HMG-CoA.
699 citations
TL;DR: This review deals with polyketides produced by the filamentous fungusMonascus which include: 1) a group of yellow, orange and red pigments, 2) agroup of antihypercholesterolemic agents including mevinolin and related compounds and 3) the newly discovered metabolite ankalactone.
Abstract: This review deals with polyketides produced by the filamentous fungusMonascus which include: 1) a group of yellow, orange and red pigments, 2) a group of antihypercholesterolemic agents including mevinolin and related compounds and 3) the newly discovered metabolite ankalactone. Biosynthesis, methods of production, isolation and biological activities of these secondary metabolites are discussed.
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