Fungal Cell Wall and Methyl-β-Cyclodextrin Synergistically Enhance Paclitaxel Biosynthesis and Secretion in Corylus avellana Cell Suspension Culture

The Impact of Cyclodextrins on the Physiology of Candida boidinii: Exploring New Opportunities in the Cyclodextrin Application

Cyclodextrins, commonly used as excipients in antifungal formulations to improve the physicochemical properties and availability of the host molecules, have not been systematically studied for their effects and bioactivity without a complex active substance. This paper evaluates the effects of various cyclodextrins on the physiology of the test organism Candida boidinii. The research examines their impact on yeast growth, viability, biofilm formation and morphological changes. Native ACD, BCD, randomly methylated α- and β-CD and quaternary ammonium α-CD and β-CD were investigated in the 0.5-12.5 mM concentration range in both static and dynamic systems. The study revealed that certain cyclodextrins exhibited notable antifungal effects (up to ~69%) in dynamic systems; however, the biofilm formation was enhanced in static systems. The magnitude of these effects was influenced by several variables, including the size of the internal cavity, the concentration and structure of the cyclodextrins, and the contact time. Furthermore, the study found that CDs exhibited distinct effects in both static and dynamic systems, potentially related to their tendency to form aggregates. The findings suggest that cyclodextrins may have the potential to act as antifungal agents or growth promoters, depending on their structure and surrounding environments.

Inducing Effect of Corylus avellana on Cytotoxic Activity in Lung and Breast Cancer Cells via Apoptosis

Turkish hazelnut (Corylus avellana L. cv Tombul) is a widely used nut in the chocolate industry and is also rich in polyphenol content, which promises anticancer effects. The anti-cancer and apoptotic effects of hazelnut leaves extracts examined on lung and breast cancer cells. Sulforhodamine B (SRB) and Adenosine 5'- triphosphate (ATP) assays were carried out for cell viability measurement. The mode of cell death was shown morphologically by the double fluorescence staining. Apoptosis was determined by performing caspase-mediated cytokeratin 18 (M30 ELISA) and western blot analysis. PARP, caspase 3, caspase 8, DR4, and GAPHD (Glyceraldehyde-3-phosphate Dehydrogenase) protein bands were visualized as markers of apoptosis. A wound healing test was employed to measure cell migration. Methanol extract of hazelnut leaf exhibited inhibition of cell growth activities in a dose-dependent manner. IC50 values were determined as 32.17 µg/ml in MCF-7, 32.16 µg/ml in MDA-MB-231, 20.40 µg/ml in A549 and 12.04 µg/ml in H1299 cells for ethanol extract while it was determined as 21.08 µg/ml in MCF-7, 40.16 µg/ml in MDA-MB-231, 22.04 µg/ml in A549 and 5.91 µg/ml in H1299 cells in methanol extract. In comparison, methanol leaf extracts were more effective in H1299 cells (IC50 value was 5.91 µg/ml).In comparison, ethanol leaf extracts were more effective in H1299 cells (IC50 value was 9.722 µg/ml). Western blot analysis demonstrated that hazelnut leaf extract treatment of cancer cells led to cell death via apoptosis and inhibited cell migration in lung and breast cancer cell lines. The cytotoxic effects of hazelnut extract on breast and lung cancer cells might be valuable and promising in elucidating cell death mechanisms for the development of new methods in cancer treatment.

Culture-based diversity of endophytic fungi of three species of Ferula grown in Iran

A total of 1,348 endophytic fungal strains were isolated from Ferula ovina, F. galbaniflua, and F. persica. They included Eurotiales (16 species), Pleosporales (11 species), Botryosphaeriales (1 species), Cladosporiales (2 species), Helotiales (6 species), Hypocreales (31 species), Sordariales (7 species), Glomerellales (2 species), and Polyporales (1 species). F. ovina had the richest species composition of endophytic fungi, and the endophytic fungi were most abundant in their roots compared to shoots. Chao, Margalef, Shannon, Simpson, Berger-Parker, Menhinick, and Camargo indices showed that F. ovina roots had the most endophytic fungal species. The frequency distribution of fungal species isolated from Ferula spp. fell into the log-series model, and F. ovina roots had the highest Fisher alpha. The dominance indices showed that there are no dominant species in the endophytic fungal community isolated from Ferula spp., indicating community stability. Evenness values were 0.69, 0.90, 0.94, and 0.57 for endophytic fungi isolated from F. ovina roots, F. ovina shoots, F. galbaniflua roots, and F. persica roots, respectively, indicating a species distribution that tends toward evenness. The fungal species community isolated from each of F. ovina roots, F. ovina shoots, F. galbaniflua roots, and F. persica roots was a diverse species group originating from a homogeneous habitat. Their distribution followed a log-normal distribution, suggesting that the interactions of numerous independent environmental factors multiplicatively control species abundances. Principal component analysis showed that the highest species diversity and dominance were observed in the endophytic fungal community isolated from F. ovina and F. persica roots, respectively.

Biocontrol of Diplodia bulgarica, the causal agent of apple canker, using Trichoderma zelobreve

Apple (Malus domestica Borkh) is one of the most consumed and nutritious fruits. Iran is one of the main producers of the apple in the world. Diplodia bulgarica is the major causal agent of apple tree decline in Iran. Biological control is a nature-friendly approach to plant disease management. Trichoderma zelobreve was isolated from apple trees infected with Diplodia bulgarica in West Azarbaijan province of Iran. The results showed that T. zelobreve strongly inhibited the colony growth of D. bulgarica. In vivo assay on detached branches of apple tree cv. Golden Delicious using T. zelobreve mycelial plug showed that canker length/stem length (CL/SL) and canker perimeter/stem perimeter (CP/SP) indices decreased by 76 and 69%, respectively, 21 days after inoculation. Additionally, wettable powder formulation (WPF) containing the antagonistic fungus "T. zelobreve" decreased CL and CP/SP by 75 and 67%, respectively, 6 months after inoculation. Moreover, canker progress curves and the area under the disease progress curve (AUDPC) supported these findings. The growth temperatures of the antagonist and pathogen were similar, indicating the adaptation of T. zelobreve for biocontrol of apple canker caused by D. bulgarica. The results also showed that T. zelobreve-based WPF stored at 25 °C assure excellent shelf life at least 4 months, allowing the bioproduct to be stored at room temperature, which is a great advantage and cost-effective option.

Eco-friendly approaches to phytochemical production: elicitation and beyond

Highly ameliorated phytochemicals from plants are recognized to have numerous beneficial effects on human health. However, obtaining secondary metabolites directly from wild plants is posing a great threat to endangered plant species due to their over exploitation. Moreover, due to complicated structure and stereospecificity chemical synthesis of these compounds is a troublesome procedure. As a result, sustainable and ecofriendly in vitro strategy has been adopted for phytochemicals production. But, lack of fully differentiated cells lowers down cultured cells productivity. Consequently, for enhancing yield of metabolites produced by cultured plant cells a variety of methodologies has been followed one such approach includes elicitation of culture medium that provoke stress responses in plants enhancing synthesis and storage of bioactive compounds. Nevertheless, for conclusive breakthrough in synthesizing bioactive compounds at commercial level in-depth knowledge regarding metabolic responses to elicitation in plant cell cultures is needed. However, technological advancement has led to development of molecular based approaches like metabolic engineering and synthetic biology which can serve as promising path for phytochemicals synthesis. This review article deals with classification, stimulating effect of elicitors on cultured cells, parameters of elicitors and action mechanism in plants, modern approaches like metabolic engineering for future advances.

Transcriptomics and Physiological Analyses Reveal Changes in Paclitaxel Production and Physiological Properties in Taxus cuspidata Suspension Cells in Response to Elicitors

In this research, the cell growth, physiological, and biochemical reactions, as well as the paclitaxel production, of Taxus cuspidata suspension cells after treatment with polyethylene glycol (PEG), cyclodextrin (CD), or salicylic acid (SA) (alone or in combination) were investigated. To reveal the paclitaxel synthesis mechanism of T. cuspidata suspension cells under elicitor treatment, the transcriptomics of the Control group and P + C + S group (PEG + CD + SA) were compared. The results show that there were no significant differences in cell biomass after 5 days of elicitor treatments. However, the content of hydrogen peroxide (H2O2) and malondialdehyde (MDA), and the activities of phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO) after elicitor combination treatments were decreased compared with the single-elicitor treatment. Meanwhile, the antioxidant enzyme activity (superoxide dismutase (SOD), catalase (CAT), and peroxidase (PO)) and the contents of soluble sugar and soluble protein were increased after combination elicitor treatments. Additionally, the paclitaxel yield after treatment with the combination of all three elicitors (P + C + S) was 6.02 times higher than that of the Control group, thus indicating that the combination elicitor treatments had a significant effect on paclitaxel production in T. cuspidata cell suspension culture. Transcriptomics analysis revealed 13,623 differentially expressed genes (DEGs) between the Control and P + C + S treatment groups. Both GO and KEGG analyses showed that the DEGs mainly affected metabolic processes. DEGs associated with antioxidant enzymes, paclitaxel biosynthesis enzymes, and transcription factors were identified. It can be hypothesized that the oxidative stress of suspension cells occurred with elicitor stimulation, thereby leading to a defense response and an up-regulation of the gene expression associated with antioxidant enzymes, paclitaxel synthesis enzymes, and paclitaxel synthesis transcription factors; this ultimately increased the production of paclitaxel.

Research Advances in Clinical Applications, Anticancer Mechanism, Total Chemical Synthesis, Semi-Synthesis and Biosynthesis of Paclitaxel

Paclitaxel, a natural secondary metabolite isolated and purified from the bark of the Taxus tree, is considered one of the most successful natural anticancer drugs due to its low toxicity, high potency and broad-spectrum anticancer activity. Taxus trees are scarce and slow-growing, and with extremely low paclitaxel content, the contradiction between supply and demand in the market is becoming more and more intense. Therefore, researchers have tried to obtain paclitaxel by various methods such as chemical synthesis, artificial culture, microbial fermentation and tissue cell culture to meet the clinical demand for this drug. This paper provides a comprehensive overview of paclitaxel extraction, combination therapy, total synthesis, semi-synthesis and biosynthesis in recent years and provides an outlook, aiming to provide a theoretical basis and reference for further research on the production and application of paclitaxel in the future.

Physiological and metabolic traits of Taxol biosynthesis of endophytic fungi inhabiting plants: Plant-microbial crosstalk, and epigenetic regulators

Attenuating the Taxol productivity of fungi with the subculturing and storage under axenic conditions is the challenge that halts the feasibility of fungi to be an industrial platform for Taxol production. This successive weakening of Taxol productivity by fungi could be attributed to the epigenetic down-regulation and molecular silencing of most of the gene clusters encoding Taxol biosynthetic enzymes. Thus, exploring the epigenetic regulating mechanisms controlling the molecular machinery of Taxol biosynthesis could be an alternative prospective technology to conquer the lower accessibility of Taxol by the potent fungi. The current review focuses on discussing the different molecular approaches, epigenetic regulators, transcriptional factors, metabolic manipulators, microbial communications and microbial cross-talking approaches on restoring and enhancing the Taxol biosynthetic potency of fungi to be industrial platform for Taxol production.

Biosynthesis of anticancer phytochemical compounds and their chemistry

Cancer is a severe health issue, and cancer cases are rising yearly. New anticancer drugs have been developed as our understanding of the molecular mechanisms behind diverse solid tumors, and metastatic malignancies have increased. Plant-derived phytochemical compounds target different oncogenes, tumor suppressor genes, protein channels, immune cells, protein channels, and pumps, which have attracted much attention for treating cancer in preclinical studies. Despite the anticancer capabilities of these phytochemical compounds, systemic toxicity, medication resistance, and limited absorption remain more significant obstacles in clinical trials. Therefore, drug combinations of new phytochemical compounds, phytonanomedicine, semi-synthetic, and synthetic analogs should be considered to supplement the existing cancer therapies. It is also crucial to consider different strategies for increased production of phytochemical bioactive substances. The primary goal of this review is to highlight several bioactive anticancer phytochemical compounds found in plants, preclinical research, their synthetic and semi-synthetic analogs, and clinical trials. Additionally, biotechnological and metabolic engineering strategies are explored to enhance the production of bioactive phytochemical compounds. Ligands and their interactions with their putative targets are also explored through molecular docking studies. Therefore, emphasis is given to gathering comprehensive data regarding modern biotechnology, metabolic engineering, molecular biology, and in silico tools.

Impact of elicitors on essential oil compositions and phytochemical constituents in Lavandula stoechas L

Lavandula stoechas L. (LS) is an aromatic evergreen herb used broadly in the food, pharmaceutical, and perfume industries. However, the inducer effect of elicitors on secondary metabolites (SMs) biosynthesis in LS is nebulous. In addition, the precise mechanism of elicitors in cells remains unexplored. Hence, the primary objective of this study was to analyze the changes in phytochemical compositions of LSs treated with a biotic elicitor (chitin) and an abiotic one (copper nanoparticle) under in vitro and greenhouse conditions, with the aim of choosing an appropriate elicitor type, concentration, and exposure time for this species. In this study, the biochemical function of four chitin concentrations (i.e. 0, 50, 100 & 200 mg L^-1) and four copper oxide nanoparticle concentrations (i.e. 0, 25, 50, & 100 mg L^-1) at two exposure times (i.e. 5 & 10 days) was investigated in LS so as to compare with the un-elicited explants and the original plant materials. The analysis showed that the highest contents of the total phenolic (4.68 mg g^-1 FW), flavonoids (0.68 mg g^-1 FW), anthocyanins (36.51 mg g^-1 FW), and flavonols (0.29 mg g^-1 FW) compounds were observed in the elicited LSs. Besides, the role of elicitors in augmenting the percentage of SMs was intelligible, especially 'lavandulol', '1,8-cineole', 'germacrene D', and '(E)-nerolidol', which increased by 21.68%, 17.21%, 9.33%, and 8.11%, respectively. In conclusion, these findings indicate that utilizing elicitors at optimal concentrations and with timely durations of exposure can largely assist in improving the biotechnological production of SMs in LS, so that their potential for industrial use can be actualized.

Biotechnology and In Vitro Culture as an Alternative System for Secondary Metabolite Production

Medicinal plants are rich sources of bioactive compounds widely used as medicaments, food additives, perfumes, and agrochemicals. These secondary compounds are produced under stress conditions to carry out physiological tasks in plants. Secondary metabolites have a complex chemical structure with pharmacological properties. The widespread use of these metabolites in a lot of industrial sectors has raised the need to increase the production of secondary metabolites. Biotechnological methods of cell culture allow the conservation of plants, as well as the improvement of metabolite biosynthesis and the possibility to modify the synthesis pathways. The objective of this review is to outline the applications of different in vitro culture systems with previously reported relevant examples for the optimal production of plant-derived secondary metabolites.

Metabolic engineering of the diosgenin biosynthesis pathway in Trigonella foenum-graceum hairy root cultures

Diosgenin as a triterpene with numbers of pharmaceutical applications has been identified in Trigonella foenum-graceum. In this survey, in order to scale up the amount of diosgenin in Fenugreek as a promising alternative of yam, ∆²⁴-reductase as a rate limiting enzyme in diosgenin biosynthesis pathway has been overexpressed by utilizing pBI121 expression plasmid in hairy roots culture platform. The recombinant binary vector pBI121-∆²⁴-reductase was transformed into R. rhizogenes strain ATCC 15834 to induce transgenic hairy roots in "Hamedan" as a low-diosgenin production genotype. In the transgenic hairy roots, the ∆²⁴-reductase expression level was significantly 8.15 times overexpressed comparing to the non-transgenic hairy roots, Nonetheless the Sterol-methyltransferase, as a competitive enzyme, was 6 times downregulated. Furthermore, the expression rate of Squalene synthase, Cycloartenol synthase, C26-Hydroxylase were also increased 1.5, 1.7, 2.9 times higher than those of the non-transgenic hairy roots, respectively. The diosgenin content in the transgenic hairy root was raised 3 times up comparing to the non-transgenic hairy roots, besides it was scaled up 25-fold comparing to the diosgenin amount in "Hamedan" Leaf. As a result, the first metabolic engineering on this pathway was clearly revealed the impact of ∆²⁴ -reductase gene in diosgenin content enhancement.

Using the Strategy of Inducing and Genetically Transforming Plant Suspension Cells to Produce High Value-Added Bioactive Substances

Plants can produce many functional bioactive substances. The suspension cell system of plants can be constructed based on its characteristics to realize the large-scale production of valuable products. In this review, we mainly talk about the main strategies, elicitation, and genetic transformation to improve the yield of active substances by using this system. Meanwhile, we focus on the challenges hiding in the practical application and the future prospects and provide new ideas and the theoretical basis for obtaining numerous bioactive substances from plants.

Production of bioactive plant secondary metabolites through in vitro technologies-status and outlook

Medicinal plants have been used by mankind since ancient times, and many bioactive plant secondary metabolites are applied nowadays both directly as drugs, and as raw materials for semi-synthetic modifications. However, the structural complexity often thwarts cost-efficient chemical synthesis, and the usually low content in the native plant necessitates the processing of large amounts of field-cultivated raw material. The biotechnological manufacturing of such compounds offers a number of advantages like predictable, stable, and year-round sustainable production, scalability, and easier extraction and purification. Plant cell and tissue culture represents one possible alternative to the extraction of phytochemicals from plant material. Although a broad commercialization of such processes has not yet occurred, ongoing research indicates that plant in vitro systems such as cell suspension cultures, organ cultures, and transgenic hairy roots hold a promising potential as sources for bioactive compounds. Progress in the areas of biosynthetic pathway elucidation and genetic manipulation has expanded the possibilities to utilize plant metabolic engineering and heterologous production in microorganisms. This review aims to summarize recent advances in the in vitro production of high-value plant secondary metabolites of medicinal importance.

Key points

• Bioactive plant secondary metabolites are important for current and future use in medicine

• In vitro production is a sustainable alternative to extraction from plants or costly chemical synthesis

• Current research addresses plant cell and tissue culture, metabolic engineering, and heterologous production

Bioproduction process of natural products and biopharmaceuticals: Biotechnological aspects

Decades of research have been put in place for developing sustainable routes of bioproduction of high commercial value natural products (NPs) on the global market. In the last few years alone, we have witnessed significant advances in the biotechnological production of NPs. The development of new methodologies has resulted in a better understanding of the metabolic flux within the organisms, which have driven manipulations to improve production of the target product. This was further realised due to the recent advances in the omics technologies such as genomics, transcriptomics, proteomics, metabolomics and secretomics, as well as systems and synthetic biology. Additionally, the combined application of novel engineering strategies has made possible avenues for enhancing the yield of these products in an efficient and economical way. Invention of high-throughput technologies such as next generation sequencing (NGS) and toolkits for genome editing Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated 9 (CRISPR/Cas9) have been the game changers and provided unprecedented opportunities to generate rationally designed synthetic circuits which can produce complex molecules. This review covers recent advances in the engineering of various hosts for the production of bioactive NPs and biopharmaceuticals. It also highlights general approaches and strategies to improve their biosynthesis with higher yields in a perspective of plants and microbes (bacteria, yeast and filamentous fungi). Although there are numerous reviews covering this topic on a selected species at a time, our approach herein is to give a comprehensive understanding about state-of-art technologies in different platforms of organisms.

A hybrid model based on general regression neural network and fruit fly optimization algorithm for forecasting and optimizing paclitaxel biosynthesis in Corylus avellana cell culture

BACKGROUND

Paclitaxel is a well-known chemotherapeutic agent widely applied as a therapy for various types of cancers. In vitro culture of Corylus avellana has been named as a promising and low-cost strategy for paclitaxel production. Fungal elicitors have been reported as an impressive strategy for improving paclitaxel biosynthesis in cell suspension culture (CSC) of C. avellana. The objectives of this research were to forecast and optimize growth and paclitaxel biosynthesis based on four input variables including cell extract (CE) and culture filtrate (CF) concentration levels, elicitor adding day and CSC harvesting time in C. avellana cell culture, as a case study, using general regression neural network-fruit fly optimization algorithm (GRNN-FOA) via data mining approach for the first time.

RESULTS

GRNN-FOA models (0.88-0.97) showed the superior prediction performances as compared to regression models (0.57-0.86). Comparative analysis of multilayer perceptron-genetic algorithm (MLP-GA) and GRNN-FOA showed very slight difference between two models for dry weight (DW), intracellular and extracellular paclitaxel in testing subset, the unseen data. However, MLP-GA was slightly more accurate as compared to GRNN-FOA for total paclitaxel and extracellular paclitaxel portion in testing subset. The slight difference was observed in maximum growth and paclitaxel biosynthesis optimized by FOA and GA. The optimization analysis using FOA on developed GRNN-FOA models showed that optimal CE [4.29% (v/v)] and CF [5.38% (v/v)] concentration levels, elicitor adding day (17) and harvesting time (88 h and 19 min) can lead to highest paclitaxel biosynthesis (372.89 µg l^-1).

CONCLUSIONS

Great accordance between the predicted and observed values of DW, intracellular, extracellular and total yield of paclitaxel, and also extracellular paclitaxel portion support excellent performance of developed GRNN-FOA models. Overall, GRNN-FOA as new mathematical tool may pave the way for forecasting and optimizing secondary metabolite production in plant in vitro culture.

Next-generation metabolic engineering approaches towards development of plant cell suspension cultures as specialized metabolite producing biofactories

Plant cell suspension culture (PCSC) has emerged as a viable technology to produce plant specialized metabolites (PSM). While Taxol® and ginsenoside are two examples of successfully commercialized PCSC-derived PSM, widespread utilization of the PCSC platform has yet to be realized primarily due to a lack of understanding of the molecular genetics of PSM biosynthesis. Recent advances in computational, molecular and synthetic biology tools provide the opportunity to rapidly characterize and harness the specialized metabolic potential of plants. Here, we discuss the prospects of integrating computational modeling, artificial intelligence, and precision genome editing (CRISPR/Cas and its variants) toolboxes to discover the genetic regulators of PSM. We also explore how synthetic biology can be applied to develop metabolically optimized PSM-producing native and heterologous PCSC systems. Taken together, this review provides an interdisciplinary approach to realize and link the potential of next-generation computational and molecular tools to convert PCSC into commercially viable PSM-producing biofactories.

Modeling of paclitaxel biosynthesis elicitation in Corylus avellana cell culture using adaptive neuro-fuzzy inference system-genetic algorithm (ANFIS-GA) and multiple regression methods

Paclitaxel as a microtubule-stabilizing agent is widely used for the treatment of a vast range of cancers. Corylus avellana cell suspension culture (CSC) is a promising strategy for paclitaxel production. Elicitation of paclitaxel biosynthesis pathway is a key approach for improving its production in cell culture. However, optimization of this process is time-consuming and costly. Modeling of paclitaxel elicitation process can be helpful to predict the optimal condition for its high production in cell culture. The objective of this study was modeling and forecasting paclitaxel biosynthesis in C. avellana cell culture responding cell extract (CE), culture filtrate (CF) and cell wall (CW) derived from endophytic fungus, either individually or combined treatment with methyl-β-cyclodextrin (MBCD), based on four input variables including concentration levels of fungal elicitors and MBCD, elicitor adding day and CSC harvesting time, using adaptive neuro-fuzzy inference system (ANFIS) and multiple regression methods. The results displayed a higher accuracy of ANFIS models (0.94-0.97) as compared to regression models (0.16-0.54). The great accordance between the predicted and observed values of paclitaxel biosynthesis for both training and testing subsets support excellent performance of developed ANFIS models. Optimization process of developed ANFIS models with genetic algorithm (GA) showed that optimal MBCD (47.65 mM) and CW (2.77% (v/v)) concentration levels, elicitor adding day (16) and CSC harvesting time (139 h and 41 min after elicitation) can lead to highest paclitaxel biosynthesis (427.92 μg l-1). The validation experiment showed that ANFIS-GA method can be a promising tool for selecting the optimal conditions for maximum paclitaxel biosynthesis, as a case study.

Mathematical Modeling of Growth and Paclitaxel Biosynthesis in Corylus avellana Cell Culture Responding to Fungal Elicitors Using Multilayer Perceptron-Genetic Algorithm

Paclitaxel is the top-selling anticancer medicine in the world. In vitro culture of Corylus avellana has been made known as a promising and inexpensive strategy for producing paclitaxel. Fungal elicitors have been named as the most efficient strategy for enhancing the biosynthesis of secondary metabolites in plant cell culture. In this study, endophytic fungal strain HEF₁₇ was isolated from C. avellana and identified as Camarosporomyces flavigenus. C. avellana cell suspension culture (CSC) elicited with cell extract (CE) and culture filtrate (CF) derived from strain HEF₁₇, either individually or combined treatment, in mid and late log phase was processed for modeling and optimizing growth and paclitaxel biosynthesis regarding CE and CF concentration levels, elicitor adding day, and CSC harvesting time using multilayer perceptron-genetic algorithm (MLP-GA). The results displayed higher accuracy of MLP-GA models (0.89-0.95) than regression models (0.56-0.85). The great accordance between the predicted and observed values of output variables (dry weight, intracellular, extracellular and total yield of paclitaxel, and also extracellular paclitaxel portion) for both training and testing subsets supported the excellent performance of developed MLP-GA models. MLP-GA method presented a promising tool for selecting the optimal conditions for maximum paclitaxel biosynthesis. An Excel^® estimator, HCC-paclitaxel, was designed based on MLP-GA model as an easy-to-use tool for predicting paclitaxel biosynthesis in C. avellana CSC responding to fungal elicitors.

Whole fungal elicitors boost paclitaxel biosynthesis induction in Corylus avellana cell culture

Paclitaxel is an effective natural-source chemotherapeutic agent commonly applied to treat a vast range of cancers. In vitro Corylus avellana culture has been reported as a promising and inexpensive system for paclitaxel production. Fungal elicitors have been made known as the most efficient strategy for the biosynthesis induction of secondary metabolites in plant in vitro culture. In this research, C. avellana cell suspension culture (CSC) was exposed to cell extract (CE) and culture filtrate (CF) derived from Camarosporomyces flavigenus, either individually or combined treatment, in mid and late log phase. There is no report on the use of whole fungal elicitors (the combined treatment of CE and CF) for the elicitation of secondary metabolite biosynthesis in plant in vitro culture. The combined treatment of CE and CF significantly led to more paclitaxel biosynthesis and secretion than the individual use of them. Also, multivariate statistical approaches including stepwise regression (SR), ordinary least squares regression (OLSR), principal component regression (PCR) and partial least squares regression (PLSR) were used to model and predict paclitaxel biosynthesis and secretion. Based on value account for (VAF), root mean square error (RMSE), coefficient of determination (R2), mean absolute percentage error (MAPE) and relative percent difference (RPD) can be concluded that mentioned regression models effectively worked only for modeling and predicting extracellular paclitaxel portion in C. avellana cell culture.