Production of mycophenolic acid by Penicillium brevicompactum immobilized in a rotating fibrous-bed bioreactor

HLA gene variations and mycotoxin toxicity: Four case reports

Mycotoxins are produced by certain molds that can cause many health effects. We present four human cases of prolonged consistent mycotoxins exposure linked to genetic variations in human leukocyte antigen (HLA) alleles. The HLA-DR/DQ isotype alleles are linked to mycotoxins susceptibility due to the lack of proper immune response; individuals with these alleles are poor eliminators of mycotoxins from their system. Four subjects with variations in their HLA-DR alleles were exposed to mycotoxins from living in mold-infested houses and experienced persistent mold-related symptoms long after moving out from the mold-infested houses and only exposed to the levels of molds found in the ambient air. From one of the subjects, two urine samples were collected ~ 18 months apart after the cessation of exposure. Urinary elimination rate was extremely slow for two of the mycotoxins (ochratoxin A [OTA] and mycophenolic acid [MPA]) detected in both samples. In 18 months, decline in OTA level was only ~ 3-fold (estimated t½ of ~ 311 days) and decline in MPA level was ~ 11-fold (estimated t½ of ~ 160 days), which was ~ 10- and ~ 213-fold slower than expected in individuals without HLA-DR alleles, respectively. We estimated that ~ 4.3 and ~ 2.2 years will be required for OTA and MPA to reach < LLQ in urine, respectively. Three other subjects with variations in HLA-DR alleles were members of a family who lived in a mold-infested house for 4 years. They kept experiencing mold-related issues >2 years after moving to a non-mold-infested house. Consistent exposure was confirmed by the presence of several mycotoxins in urine >2 years after the secession of higher than background (from outdoor ambient air) exposure. This was consistent with the extremely slow elimination of mycotoxins from their system. Variations in HLA-DR alleles can, consequently, make even short periods of exposure to chronic exposure scenarios with related adverse health effects. It is, therefore, important to determine genetic predisposition as a reason for prolonged/lingering mold-related symptoms long after the cessation of higher than background exposure. Increased human exposure to mycotoxins is expected from increased mold infestation that is anticipated due to rising CO2, temperature, and humidity from the climate change with possibly increased adverse health effects, especially in individuals with genetic susceptibility to mold toxicity.

Enhanced Production of Mycophenolic Acid from Penicillium brevicompactum via Optimized Fermentation Strategy

Mycophenolic acid (MPA) is an occurring antibiotic produced through Penicillium brevicompactum. Its production was achieved by systematic process optimization under submerged fermentation. In shake flask, single-factor test experiments, Box-Behnken design (BBD) experiments, and fermentation strategy were determined, and the MPA yield was reached at 3002 ± 47, 3610 ± 51, and 4748 ± 59 µg/mL, respectively. For fermentation strategy, MPA production was 58.1% higher than that initial fermentation condition without optimization. Then, the optimized medium was further carried out in 5-L stirred fermenter for 180 h; MPA titer was increased from 3712 ± 65 µg/mL to 5786 ± 76 µg/mL, 55.9% higher than that of single-factor optimized medium. The results of this investigation will provide a vital step toward industrial-scale production of MPA.

Production of Mycophenolic Acid by a Newly Isolated Indigenous Penicillium glabrum

Soil-occupant fungi produce a variety of mycotoxins as secondary metabolites, one of which is mycophenolic acid (MPA), an antibiotic and immunosuppressive agent. MPA is mainly produced by several species of Penicillium, especially Penicillium brevicompactum. Here, we present the first report of MPA production by a local strain belonging to Penicillium glabrum species. We screened ascomycete cultures isolated from moldy food and fruits, as well as soils, collected from different parts of Iran. MPA production of one hundred and forty Penicillium isolates was analyzed using HPLC. Three MPA producer isolates were identified, among which the most producer was subjected to further characterization, based on morphological and microscopic analysis, as well as molecular approach (ITS, rDNA and beta-tubulin gene sequences). The results revealed that the best MPA producer belongs to P. glabrum IBRC-M 30518, and can produce 1079 mg/L MPA in Czapek-Dox medium.

Machine Learning Modeling for Ultrasonication-Mediated Fermentation of Penicillium brevicompactum to Enhance the Release of Mycophenolic Acid

Described here is the modeling used to improve the mycophenolic acid (MPA) titer from Penicillium brevicompactum using central composite design and a comparatively newer, data-centric approach method k-nearest-neighbor algorithm. The two models for enhancing MPA production using P. brevicompactum were compared with respect to ultrasonic stimulation. During the ultrasonic treatment, we studied different independent factors such as ultrasound power, irradiation duration, treatment frequency and duty cycle to determine their ability to enhance the MPA titer value. The optimized factors such as a treatment time of 10 min (50% duty cycles) with a 12-h interlude at fixed ultrasonic power and frequency (200 W, 40 kHz) were used for ultrasonic treatment of a mycelial culture from the 2nd to 10th day of fermentation. Thus the production of MPA was improved 1.64-fold under the optimized sonication conditions compared with the non-sonicated batch fermentation (non-optimized conditions).

Liposomal Delivery of Mycophenolic Acid With Quercetin for Improved Breast Cancer Therapy in SD Rats

The present study explores the influence of mycophenolic acid (MPA) in combination therapy with quercetin (QC) (impeding MPA metabolic rate) delivered using the liposomal nanoparticles (LNPs). Mycophenolic acid liposome nanoparticles (MPA-LNPs) and quercetin liposome nanoparticles (QC-LNPs) were individually prepared and comprehensively characterized. The size of prepared MPA-LNPs and QC-LNPs were found to be 183 ± 13 and 157 ± 09.8, respectively. The in vitro studies revealed the higher cellular uptake and cytotoxicity of combined therapy (MPA-LNPs + QC-LNPs) compared to individual ones. Moreover pharmacokinetics studies in female SD-rat shown higher T 1 / 2 value (1.94 fold) of combined therapy compared to MPA. Furthermore, in vivo anticancer activity in combination of MPA-LNPs and QC-LNPs was also significantly higher related to other treatments groups. The combination therapy of liposomes revealed the new therapeutic approach for the treatment of breast cancer.

Semi-continuous production of the anticancer drug taxol by Aspergillus fumigatus and Alternaria tenuissima immobilized in calcium alginate beads

Taxol is the most profitable drug ever developed in cancer chemotherapy; however, the market demand for the drug greatly exceeds the supply that can be sustained from its natural sources. In this study, Aspergillus fumigatus TXD105-GM6 and Alternaria tenuissima TER995-GM3 were immobilized in calcium alginate beads and used for the production of taxol in shake flask cultures. In an effort to increase the taxol magnitude, immobilization conditions were optimized by response surface methodology program (RSM). The optimum levels of alginate concentration, calcium chloride concentration, and mycelium fresh weight were 5%, 4%, and 15% (w/v), respectively. Under these conditions, taxol production by the respective fungal strains was intensified to 901.94 μg L^-1 and 529.01 μg L^-1. Moreover, the immobilized mycelia of both strains were successfully used in the repeated production of taxol for six different fermentation cycles. The total taxol concentration obtained in all cycles reached 4540.14 μg L^-1 by TXD105-GM6 and 2450.27 μg L^-1 by TER995-GM3 strain, which represents 7.85- and 6.31-fold increase, as compared to their initial titers. This is the first report on the production of taxol in semi-continuous fermentation. To our knowledge, the taxol productivity achieved in this study is the highest reported by academic laboratories for microbial cultures which indicates the future possibility to reduce the cost of taxol production.

Optimization Strategies for Purification of Mycophenolic Acid Produced by Penicillium brevicompactum

The microbial fermentation of Penicillium brevicompactum produces secondary metabolite mycophenolic acid (MPA), which exhibits antifungal, antiviral, antibacterial, and antitumor activity. It is also a potent, selective, non-competitive, and reversible inhibitor of the human inosine monophosphate dehydrogenase (IMPDH). This study is an attempt to optimize the MPA production through a fermentation process using Penicillium brevicompactum and its further purification process optimization. In the batch fermentation process, the maximum concentration of MPA (1.84 g/L) was attained in a 3.7 L stirred tank reactor. Response surface methodology (RSM) using central composite design (CCD) was employed as a statistical tool to investigate the effect of pH, the volume of eluent and flow rate of the mobile phase on MPA purification process. Under optimum conditions, the experimental yield was observed to be 84.12%, which matched well with the predictive yield of 84.42%. High-performance liquid chromatography (HPLC) and Fourier-transform infrared spectroscopy (FTIR) analysis of the fermented product was carried out to confirm the presence of mycophenolic acid. The MPA purification was done by using column chromatography technique. The purification of broth involved mycophenolic acid extraction by selecting different solvents on the basis of polarity and the extraction efficiency of solvent. Various solid support materials were used for MPA purification in column chromatography. The MPA recovery through alumina column was observed to be 84.12% under the optimum conditions, which was maximum elution as compared with other support materials. The optimized purification process yielded pure MPA crystals.

Strain improvement and immobilization technique for enhanced production of the anticancer drug paclitaxel by Aspergillus fumigatus and Alternaria tenuissima

UV and gamma irradiation mutagenesis was applied on Aspergillus fumigatus and Alternaria tenuissima in order to improve their producing ability of paclitaxel. Among the screened mutants, two stable strains (designated TXD105-GM6 and TER995-GM3) showed the maximum paclitaxel production. Paclitaxel titers of the two respective mutants were dramatically intensified to 1.22- and 1.24-fold, as compared by their respective parents. Immobilization using five different entrapment carriers of calcium alginate, agar-agar, Na-CMC, gelatin, and Arabic gum was successfully applied for production enhancement of paclitaxel by the two mutants. The immobilized cultures were superior to free-cell cultures and paclitaxel production by the immobilized mycelia was much higher than that of the immobilized spores using all the tried carriers. Moreover, calcium alginate gel beads were found the most conductive and proper entrapment carrier for maximum production of paclitaxel. The feasibility of the paclitaxel production by the immobilized mycelia as affected by incubation period, medium volume, and number of beads per flask was adopted. Under the favorable immobilization conditions, the paclitaxel titers were significantly intensified to 1.31- and 1.88-fold by the respective mutants, as compared by their free cultures. The obtained paclitaxel titers by the immobilized mycelia of the respective mutants (694.67 and 388.65 μg L^-1) were found promising in terms of fungal production of paclitaxel. Hence, these findings indicate the future possibility to reduce the cost of producing paclitaxel and suggest application of the immobilization technique for the biotechnological production of paclitaxel at an industrial scale.

High efficiency succinic acid production from glycerol via in situ fibrous bed bioreactor with an engineered Yarrowia lipolytica

In this study, in situ fibrous bed bioreactor (isFBB) was developed at the first time for efficient succinic acid (SA) production by Yarrowia lipolytica. After optimization, SA titer, productivity and yield of 51.9g/L, 1.46g/L/h and 0.42g/g were obtained respectively via isFBB fermentation under conditions of 750cm² cotton towel, 120g/L initial glycerol and 3L/min aeration rate. By fed batch strategy, SA titer raised up to 198.2g/L was achieved, which was the highest value ever reported. In operation stability study, SA productivity showed no obvious decrease after 12 repeated batches of 460h fermentation, and cell viability even recovered within two repeated batches after intentional interruption. This study successfully attained a highly efficient and stable isFBB for enhanced SA production by Y. lipolytica.

Production of mycophenolic acid by Penicillium brevicompactum-A comparison of two methods of optimization

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Medium optimization for MPA production using P. brevicompactum by one-factor-at-a-time and CCD methods.

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CCD afforded a 40% higher MPA titer than one-factor-at-a-time method.

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The titer was nearly 6-fold higher compared to un-optimized medium.

Production of mycophenolic acid (MPA) by submerged fermentation using the microfungus Penicillium brevicompactum MTCC 8010 is reported here. Screening experiments were used to identify: the suitable media composition; the optimal initial pH; and the optimal incubation temperature to maximize the production of MPA in batch cultures. The initial concentrations of the selected sources of carbon (glucose), nitrogen (peptone) and the precursors (methionine, glycine) were then optimized by: (1) one-at-a-time variation of factors; and (2) a central composite design (CCD) of experiments, in a 12-day batch culture at an initial pH of 5.0, an incubation temperature of 25 °C, and an agitation speed of 200 rpm. The medium optimized using the one-at-a-time variation yielded a peak MPA titer of 1232 ± 90 mg/L. The medium optimized by the CCD method yielded a 40% higher MPA titer of 1737 ± 55 mg/L. The latter value was nearly 9-fold greater than the titer achieved prior to optimization.

Toward a Cancer Drug of Fungal Origin

Although fungi produce highly structurally diverse metabolites, many of which have served as excellent sources of pharmaceuticals, no fungi-derived agent has been approved as a cancer drug so far. This is despite a tremendous amount of research being aimed at the identification of fungal metabolites with promising anticancer activities. This review discusses the results of clinical testing of fungal metabolites and their synthetic derivatives, with the goal to evaluate how far we are from an approved cancer drug of fungal origin. Also, because in vivo studies in animal models are predictive of the efficacy and toxicity of a given compound in a clinical situation, literature describing animal cancer testing of compounds of fungal origin is reviewed as well. Agents showing the potential to advance to clinical trials are also identified. Finally, the technological challenges involved in the exploitation of fungal biodiversity and procurement of sufficient quantities of clinical candidates are discussed, and potential solutions that could be pursued by researchers are highlighted.

Enhanced cellulase production by Trichoderma viride in a rotating fibrous bed bioreactor

Filamentous fungi are widely used to produce cellulase, but how the fermentation conditions affect their production is not well known. In this study, cellulase production by Trichoderma viride in submerged fermentations with free cells in a stirred-tank reactor (STR) and immobilized cells in a rotating fibrous-bed bioreactor (RFBB) were investigated. Compared to free-cell fermentation, immobilized-cell fermentation gave 35.5% higher FPase activity and 69.7% higher saccharification yield of sugarcane bagasse (SCB). The secretory proteins in the fermentation broths were analyzed with two-dimensional gel electrophoresis (2-DE) and MALDI-TOF-TOF mass spectrometry, which identified 24 protein spots with differential expression levels. Among them, cellobiohydrolase CBH II and endoglucanase EG II were highly expressed and secreted in the immobilized-cell fermentation, while the free-cell fermentation produced more CBH І and EG ІV. These results showed that immobilized-cell fermentation with T. viride in the RFBB was advantageous for cellulase production.

Biotransformation of Panax notoginseng saponins into ginsenoside compound K production by Paecilomyces bainier sp. 229

AIMS

Development and optimization of an efficient and inexpensive biotransformation process for ginsenoside compound K production by Paecilomyces bainier sp. 229.

METHODS AND RESULTS

We have determined the optimum culture conditions required for the efficient production of ginsenoside compound K by P. bainier sp. 229 via biotransformation of ginseng saponin substrate. The optimal medium constituents were determined to be: 30 g sucrose, 30 g soybean steep powder, 1 g wheat bran powder, 1 g (NH(4))(2)SO(4), 2 g MgSO(4) x 7H(2)O and 1 g CaCl(2) in 1 l of distilled water. An inoculum size of 5-7.5% with an optimal pH range of 4.5-5.5 was essential for high yield.

CONCLUSIONS

The Mol conversion quotient of ginseng saponins increased from 21.2% to 72.7% by optimization of the cultural conditions. Scale-up in a 10 l fermentor, under conditions of controlled pH and continuous air supply in the optimal medium, resulted in an 82.6% yield of ginsenoside compound K.

SIGNIFICANT AND IMPACT OF THE STUDY

This is the first report on the optimization of culture conditions for the production of ginsenoside compound K by fungal biotransformation. The degree of conversion is significantly higher than previous reports. Our method describes an inexpensive, rapid and efficient biotransformation system for the production of ginsenoside compound K.