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

Enhancing bioprocessing of red pigment from immobilized culture of gamma rays mutant of the endophytic fungus Monascus ruber SRZ112

Considerable attention has been paid to exploring the biotechnological applications of several Monascus sp. for pigment production. In this study, our focus is on enhancing the bioprocessing of red pigment (RP) derived from the endophytic fungus Monascus ruber SRZ112. To achieve this, we developed a stable mutant strain with improved productivity through gamma irradiation. This mutant was then employed in the immobilization technique using various entrapment carriers. Subsequently, we optimized the culture medium for maximal RP production using the Response Surface Methodology. Finally, these immobilized cultures were successfully utilized for RP production using a semi-continuous mode of fermentation. After eight cycles of fermentation, the highest RP yield by immobilized mycelia reached 309.17 CV mL-1, a significant increase compared to the original titer. Importantly, this study marks the first report on the successful production of Monascus RP in a semi-continuous mode using gamma rays' mutant strain, offering prospects for commercial production.

Bioprospecting endophytic fungi for bioactive metabolites with seed germination promoting potentials

There is an urgent need for new bioactive molecules with unique mechanisms of action and chemistry to address the issue of incorrect use of chemical fertilizers and pesticides, which hurts both the environment and the health of humans. In light of this, research was done for this work to isolate, identify, and evaluate the germination-promoting potential of various plant species' fungal endophytes. Zea mays L. (maize) seed germination was examined using spore suspension of 75 different endophytic strains that were identified. Three promising strains were identified through screening to possess the ability mentioned above. These strains Alternaria alternate, Aspergilus flavus, and Aspergillus terreus were isolated from the stem of Tecoma stans, Delonix regia, and Ricinus communis, respectively. The ability of the three endophytic fungal strains to produce siderophore and indole acetic acid (IAA) was also examined. Compared to both Aspergillus flavus as well as Aspergillus terreus, Alternaria alternata recorded the greatest rates of IAA, according to the data that was gathered. On CAS agar versus blue media, all three strains failed to produce siderophores. Moreover, the antioxidant and antifungal potentials of extracts from these fungi were tested against different plant pathogens. The obtained results indicated the antioxidant and antifungal activities of the three fungal strains. GC-Mass studies were carried out to determine the principal components in extracts of all three strains of fungi. The three strains' fungus extracts included both well-known and previously unidentified bioactive compounds. These results may aid in the development of novel plant growth promoters by suggesting three different fungal strains as sources of compounds that may improve seed germination. According to the study that has been given, as unexplored sources of bioactive compounds, fungal endophytes have great potential.

Optimization of the fermentation media, mathematical modeling, and enhancement of paclitaxel production by Alternaria alternata after elicitation with pectin

Alternaria alternata fungus is a potent paclitaxel producer isolated from Corylus avellana. The major challenge is the lack of optimized media for endophytic fungi productivity. In the effort to maximize the production of taxoids by A. alternata, several fermentation conditions, including pH (pH 4.0-7.0), different types and concentrations of carbon (fructose, glucose, sucrose, mannitol, sorbitol, and malt extract), and nitrogen (urea, ammonium nitrate, potassium nitrate, ammonium phosphate, and ammonium sulfate) were applied step by step. Based on the results, A. alternata in a medium containing sucrose 5% (w/v) and ammonium phosphate 2.5 mM at pH 6.0 showed a rapid and sustainable growth rate, the highest paclitaxel yield (94.8 µg gFW-1 vs 2.8 µg gFW-1 in controls), and the maximum content of amino acids. Additionally, the effect of pectin was evaluated on fungus, and mycelia harvested. Pectin significantly enhanced the growth and taxoid yield on day 21 (respectively 171% and 116% of their corresponding on day 7). The results were checked out by mathematical modeling as well. Accordingly, these findings suggest a low-cost, eco-friendly, and easy-to-produce approach with excellent biotechnological potential for the industrial manufacture of taxoids.

Alternaria alternata F3, a Novel Taxol-Producing Endophytic Fungus Isolated from the Fruits of Taxus cuspidata: Isolation, Characterization, Taxol Yield Improvement, and Antitumor Activity

In this study, a novel taxol-producing endophytic fungus, strain F3, was isolated from the fruits of Taxus cuspidata and identified as Alternaria alternata according to its macroscopic and microscopic traits and sequence analysis of internal transcribed spacer (ITS). The presence of taxol was detected by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) and confirmed by ultra-high-performance liquid chromatography-electrospray coupled to tandem mass spectrometry (UPLC-ESI-MS/MS) and nuclear magnetic resonance (NMR). The fermentation parameters of strain F3 were then optimized for high taxol production. The maximum taxol yield of 195.4 µg L-1 by A. alternata F3 was observed in 200-mL yeast peptone dextrose (YPD) broth, at an initial pH value of 6.0, supplemented with 0.1 g L-1 sodium acetate, 0.25 g L-1 salicylic acid, and 0.00125 g L-1 silver nitrate and inoculum size 2%, and incubated at 28 °C and 150 rpm for 8 days, which was 2.12-fold compared with the initial yield of taxol. Also, fungal taxol exhibited antitumor activity towards human lung carcinoma (A549) cell line and human cervical carcinoma (Hela) cell line with IC50 values of 3.98 µg mL-1 and 0.35 µg mL-1. Overall, this is the first report on taxol-producing endophytic fungus isolated from the fruits of Taxus. This study offers a novel source for the production of taxol for anticancer treatment.

Way to efficient microbial paclitaxel mass production

The microbial synthesis of paclitaxel is attractive for its short-cycle, cost-effectiveness, and sustainability. However, low paclitaxel productivity, depleted capacity during subculture and storage, and unclear biosynthesis mechanisms restrain industrial microbial synthesis. Along with the isolation of various paclitaxel-producing microorganisms and the development of versatile molecular tools, tremendous promises for microbial paclitaxel synthesis have become increasingly prominent. In this review, we summarize the progress of microbial synthesis of paclitaxel in recent years, focusing on paclitaxel-producing endophytes and representative engineering microorganism hosts that were used as chassis for paclitaxel precursor synthesis. Numerous wide-type microbes can manufacture paclitaxel, and fermentation process optimization and strain improvement can greatly enhance the productivity. Engineered microbes can efficiently synthesize precursors of paclitaxel by introducing exogenous synthetic pathway. Mining paclitaxel synthetic pathways and genetic manipulation of endophytes will accelerate the construction of microbial cell factories, indefinitely contributing to paclitaxel mass production by microbes. This review emphasizes the potential and provides solutions for efficient microbial paclitaxel mass production.

Fusarium solani PQF9 Isolated from Podocarpus pilgeri Growing in Vietnam as a New Producer of Paclitaxel

Endophytic fungi are known as an alternative promising source of anticancer drug, paclitaxel, however fungi inhabiting in medicinal plant Podocarpus pilgeri and their paclitaxel production have not been reported to date. In the present study, a total of 15 culturable fungi classified into 5 genera, were successfully recovered from P. pilgeri collected in Vietnam. Screening fungal dichloromethane extracts for anticancer activity revealed that only PQF9 extract displayed potent inhibitory effects on A549 and MCF7 cancer cell lines with IC50 values of 33.9 ± 2.3 µg/mL and 43.5 ± 1.7 µg/mL, respectively. Through PCR-based molecular screening, the isolate PQF9 was found to possess 3 key genes involved in paclitaxel biosynthesis. Importantly, high-performance liquid chromatography quantification showed that fungal isolate PQF9 was able to produce 18.2 µg/L paclitaxel. The paclitaxel-producing fungus was identified as Fusarium solani PQF9 based on morphological and molecular phylogenetic analysis. Intensive investigations by chromatographic methods and spectroscopic analyses confirmed the presence of paclitaxel along with tyrosol and uracil. The pure paclitaxel had an IC50 value of 80.8 ± 9.4 and 67.9 ± 7.0 nM by using cell viability assay on A549 lung and MCF7 breast cancer cells. In addition, tyrosol exhibited strong antioxidant activity by scavenging 2, 2-diphenyl-picrylhydrazyl (DPPH) (IC50 5.1 ± 0.2 mM) and hydroxyl radical (IC50 3.6 ± 0.1 mM). In contrast, no biological activity was observed for uracil. Thus, the paclitaxel-producing fungus F. solani PQF9 could serve as a new material for large-scale production and deciphering paclitaxel biosynthesis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-023-01119-z.

Unlocking the biosynthetic potential of Penicillium roqueforti for hyperproduction of the immunosuppressant mycophenolic acid: Gamma radiation mutagenesis and response surface optimization of fermentation medium

Based on the broad clinical utility of the immunosuppressant mycophenolic acid (MPA), this article aims to intensify the biosynthetic potential of Penicillium roqueforti for more effective hyperproduction of the drug. Several mutants were generated from irradiation mutagenesis and screened. Two strains (GM1013 and GM1093) presented an elevated MPA productivity with significant yield constancy over 10 subsequent generations. By investigating the effect of some phosphorous sources and mineral salts on MPA production by the two mutants, KH₂ PO₄ and FeSO₄ ·7H₂ O were most preferred by the two mutants for higher MPA production rates. Statistics-dependent experimental designs were also employed for optimizing medium components for maximum MPA production. Medium components were primarily screened using the Plackett-Burman model to demonstrate the most important components that most significantly affect MPA production. The concentrations of these significant components were then optimized through a central composite rotatable model. In conclusion, gamma-radiation mutation and response surface optimization resulted in a promising MPA productivity by P. roqueforti GM1013. To our knowledge, the MPA-yield achieved in this study (2933.32 mg L^-1 ) is the highest reported by academic laboratories from P. roqueforti cultures, which could be of economic value for a prospective large industrialized application.

Bioprospecting endophytic fungi for antifeedants and larvicides and their enhancement by gamma irradiation

The search and discovery of new natural products with antifeedant and larvicidal potentials to mitigate harmful insects are scientific pressing issues in the modern agriculture. In this paper, the antifeedant and larvicidal potentials of 69 fungal isolates were screened against the Egyptian cotton leafworm Spodoptera littoralis. A total of 17 isolates showed the insecticidal potentials with three promising isolates. These strains were Aspergillus sydowii, Lasiodiplodia theobromae, and Aspergillus flavus isolated from Ricinus communis (bark), Terminalia arjuna (Bark), and Psidium guajava (twigs), respectively. The effect of gamma irradiation on the antifeedant and larvicidal activities of the three strains was investigated. Exposure of the fungal spores to 1000 Gy of gamma rays significantly intensified both the antifeedant and larvicidal potentials. To identify compounds responsible for these activities, extracts of the three strains were fractionated by thin layer chromatography. The nature of the separated compounds namely, Penitrem A, 1, 3, 5, 8- tetramethyl- 4, 6-diethyl- 7- [2- (methoxycarbonyl)ethyl] porphyrin (from A. sydowii), Penitrem A, 2, 7, 12, 17-Tetramethyl-3, 5:8, 10:13, 15:18, 20-tetrakis (2,2-dimethylpropano) porphyrin (from A. flavus), N,N-Diethyl-3-nitrobenzamide, and Diisooctyl-phthalate (from L. theobromae) were studied by GC-MS analysis. These findings recommend endophytic fungi as promising sources of novel natural compounds to mitigate harmful insects.

Three promising fungal endophytes with antifeedant and larvicidal activities were reported.

The antifeedant and larvicidal activities were intensified following exposure of fungal spores to 1000 Gy gamma rays.

Extracts of the three strains were separately fractionated by TLC then GC-MS was used to identify chemical constituents responsible for bioactivity.

Improving carboxymethyl cellulose edible coating using ZnO nanoparticles from irradiated Alternaria tenuissima

In this paper, gamma-irradiation was successfully used to intensify the yield of Zinc oxide nanoparticles (ZnONPs) produced by the fungus Alternaria tenuissima as a sustainable and green process. The obtained data showed that 500 Gy of gamma-irradiation increased ZnONPs' yield to approximately four-fold. The synthesized ZnONPs were then exploited to develop active Carboxymethyl Cellulose films by casting method at two different concentration of ZnONPs 0.5% and 1.0%. The physicochemical, mechanical, antioxidant, and antimicrobial properties of the prepared films were evaluated. The incorporation of ZnONPs in the Carboxymethyl Cellulose films had significantly decreased solubility (from 78.31% to 66.04% and 59.72%), water vapor permeability (from 0.475 g m-2 to 0.093 g m-2 and 0.026 g m-2), and oxygen transfer rate (from 24.7 × 10-2 to 2.3 × 10-2 and 1.8 × 10-2) of the respective prepared films. Meanwhile, tensile strength (from 183.2 MPa to 203.34 MPa and 235.94 MPa), elongation (from 13.0% to 62.5% and 83.7%), and Yang's modulus (from 325.344 to 1410.0 and 1814.96 MPa) of these films were increased. Moreover, the antioxidant and antimicrobial activities against several human and plant pathogens the prepared of Carboxymethyl Cellulose-ZnONPs films were significantly increased. In conclusion, the prepared Carboxymethyl Cellulose-ZnONPs films showed enhanced activities in comparison with Carboxymethyl Cellulose film without NPs. With these advantages, the fabricated Carboxymethyl Cellulose-ZnONPs films in this study could be effectively utilized as protective edible coating films of food products.

A new endophyte Monascus ruber SRZ112 as an efficient production platform of natural pigments using agro-industrial wastes

A number of biopigment applications in various industrial sectors are gaining importance due to the growing consumer interest in their natural origin. Thus, this work was conducted to valorize endophytic fungi as an efficient production platform for natural pigments. A promising strain isolated from leaves of Origanum majorana was identified as Monascus ruber SRZ112 produced several types of pigments. The nature of the pigments, mainly rubropunctamine, monascin, ankaflavin, rubropunctatin, and monascorubrin in the fungal extract was studied by LC/ESI-MS/MS analyses. As a first step towards developing an efficient production of red pigments, the suitability of seven types of agro-industrial waste was evaluated. The highest yield of red pigments was obtained using potato peel moistened with mineral salt broth as a culture medium. To increase yield of red pigments, favourable culture conditions including incubation temperature, incubation period, pH of moistening agent, inoculum concentration, substrate weight and moisture level were evaluated. Additionally, yield of red pigments was intensified after the exposure of M. ruber SRZ112 spores to 1.00 KGy gamma rays. The final yield was improved by a 22.12-fold increase from 23.55 to 3351.87 AU g-1. The anticancer and antioxidant properties of the pigment's extract from the fungal culture were also studied. The obtained data indicated activity of the extract against human breast cancer cell lines with no significant cytotoxicity against normal cell lines. The extract also showed a free radical scavenging potential. This is the first report, to our knowledge, on the isolation of the endophytic M. ruber SRZ112 strain with the successful production of natural pigments under solid-state fermentation using potato peel as a substrate.

Bioprospecting endophytic fungi for bioactive metabolites and use of irradiation to improve their bioactivities

The search for new bioactive compounds with innovative modes of action and chemistry are desperately needed to tackle the increased emergence of drug-resistant microbes. With this view, this paper was conducted for the isolation, identification, and biological evaluation of fungal endophytes of eleven different plant species. A total of 69 endophytic strains were isolated and tested for the presence of bioactive metabolites with antifungal, antibacterial, anticancer, and antioxidant properties in their extracts. Upon screening, two promising strains were found to have all the before-mentioned activities. These strains were Aspergillus sydowii isolated from the bark of Ricinus communis and Aspergillus flavus isolated from the twigs of Psidium guajava. Major compounds present in extracts of the two strains were identified by GC-Mass analyses. Several well-known bioactive compounds as well as unreported ones were identified in the fungal extracts of the two strains. Furthermore, gamma irradiation (at 1000 Gy) of the fungal cultures resulted in improved bioactivities of extracts from the two strains. These findings recommend the two fungal strains as sources of antimicrobial, anticancer, and antioxidant compounds which may aid in the development of novel drugs. The presented research also explains the high-value of fungal endophytes as untapped sources of bioactive metabolites.

Bioprospecting endophytic fungi for bioactive metabolites and use of irradiation to improve their bioactivities

The search for new bioactive compounds with innovative modes of action and chemistry are desperately needed to tackle the increased emergence of drug-resistant microbes. With this view, this paper was conducted for the isolation, identification, and biological evaluation of fungal endophytes of eleven different plant species. A total of 69 endophytic strains were isolated and tested for the presence of bioactive metabolites with antifungal, antibacterial, anticancer, and antioxidant properties in their extracts. Upon screening, two promising strains were found to have all the before-mentioned activities. These strains were Aspergillus sydowii isolated from the bark of Ricinus communis and Aspergillus flavus isolated from the twigs of Psidium guajava. Major compounds present in extracts of the two strains were identified by GC-Mass analyses. Several well-known bioactive compounds as well as unreported ones were identified in the fungal extracts of the two strains. Furthermore, gamma irradiation (at 1000 Gy) of the fungal cultures resulted in improved bioactivities of extracts from the two strains. These findings recommend the two fungal strains as sources of antimicrobial, anticancer, and antioxidant compounds which may aid in the development of novel drugs. The presented research also explains the high-value of fungal endophytes as untapped sources of bioactive metabolites.

Exploiting the exceptional biosynthetic potency of the endophytic Aspergillus terreus in enhancing production of Co3O4, CuO, Fe3O4, NiO, and ZnO nanoparticles using bioprocess optimization and gamma irradiation

Developing a suitable applicative process and scaling up the microbial synthesis of nanomaterials is an attractive and emerging prospect for a future sustainable industrial production. In this paper, optimization of fermentation conditions for enhanced production of Co₃O₄, CuO, Fe₃O₄, NiO, and ZnO nanoparticles by the endophytic A. terreus ORG-1 was studied. Different cultivation conditions were evaluated. Then, a response surface methodology program was used to optimize physical conditions controlling the biosynthesis of these NPs. Finally, the use of gamma irradiation for improvement of NPs’ production was adopted. Under the optimum conditions and after gamma irradiation, the final yields of the respective NPs reached 545.71, 651.67, 463.19, 954.88, 1356.42 mg L⁻¹. To the best of our knowledge, this is the first report on the production and enhancement of different types of nanomaterials from one microbial culture that can open up the way towards the industrialization of the microbial production of nanomaterials.

Endophytic fungus Pseudodidymocyrtis lobariellae KL27 promotes taxol biosynthesis and accumulation in Taxus chinensis

BACKGROUND

Taxol from Taxus species is a precious drug used for the treatment of cancer and can effectively inhibit the proliferation of cancer cells. However, the growth of Taxus plants is very slow and the content of taxol is quite low. Therefore, it is of great significance to improve the yield of taxol by modern biotechnology without destroying the wild forest resources. Endophytic fungus which symbiosis with their host plants can promote the growth and secondary metabolism of medicinal plants.

RESULTS

Here, an endophytic fungus KL27 was isolated from T. chinensis, and identified as Pseudodidymocyrtis lobariellae. The fermentation broth of KL27 (KL27-FB) could significantly promote the accumulation of taxol in needles of T. chinensis, reaching 0.361 ± 0.082 mg/g·DW (dry weight) at 7 days after KL27-FB treatment, which is 3.26-fold increase as compared to the control. The RNA-seq and qRT-PCR showed that KL27-FB could significantly increase the expression of key genes involved in the upstream pathway of terpene synthesis (such as DXS and DXR) and those in the taxol biosynthesis pathway (such as GGPPS, TS, T5OH, TAT, T10OH, T14OH, T2OH, TBT, DBAT and PAM), especially at the early stage of the stimulation. Moreover, the activation of jasmonic acid (JA) biosynthesis and JA signal transduction, and its crosstalk with other hormones, such as gibberellin acid (GA), ethylene (ET) and salicylic acid (SA), explained the elevation of most of the differential expressed genes related to taxol biosynthesis pathway. Moreover, TF (transcriptional factor)-encoding genes, including MYBs, ethylene-responsive transcription factors (ERFs) and basic/helix-loop-helix (bHLH), were detected as differential expressed genes after KL27-FB treatment, further suggested that the regulation of hormone signaling on genes of taxol biosynthesis was mediated by TFs.

CONCLUSIONS

Our results indicated that fermentation broth of endophytic fungus KL27-FB could effectively enhance the accumulation of taxol in T. chinensis needles by regulating the phytohormone metabolism and signal transduction and further up-regulating the expression of multiple key genes involved in taxol biosynthesis. This study provides new insight into the regulatory mechanism of how endophytic fungus promotes the production and accumulation of taxol in Taxus sp.

New and potent production platform of the acetylcholinesterase inhibitor huperzine A by gamma-irradiated Alternaria brassicae under solid-state fermentation

Huperzine-A (HupA) is an emerging, powerful, and promising natural acetylcholinesterase inhibitor. Despite that, the achieved yields of HupA from microbial sources are still far from the industrial applications. Accordingly, this paper was conducted to valorize solid-state fermentation (SSF) as an efficient production platform of HupA. Four agro-industrial wastes, namely rice bran, potato peel, sugarcane bagasse, and wheat bran, were tested and screened as cultural substrates for the production of HupA by the endophytic Alternaria brassica under SSF. Maximum HupA production was attained on using rice bran moistened by Czapex's dox mineral broth. In the effort to increase the HupA titer, supplementation of the best moistening agent by different carbon and nitrogen sources was successfully investigated. Additionally, factors affecting HupA production under SSF including substrate concentration, moistening level, and inoculum concentration were optimized using response surface methodology. A Box-Behnken design was applied for generating a predictive model of the interactions between these factors. Under the optimum conditions of 15 g rice bran, inoculum concentration of 5 × 10⁶ spores mL^-1, and 60% moisture level, HupA concentration was intensified to 518.93 μg g^-1. Besides, HupA production by the fungal strain was further enhanced using gamma-irradiation mutagenesis. The final HupA production was significantly intensified following exposure to 0.5 KGy gamma radiation to 1327 μg g^-1, which represents a 12.85-fold increase. This is the first report on the successful production of the natural fungal metabolite HupA under SSF. Moreover, the achieved yield in this study using agro-industrial wastes may contribute to reducing the cost of HupA manufacture.Key points• Different agro-industrial by-products were tried as cultural substrates for the production of the acetylcholinesterase inhibitor HupA under SSF for the first time.• Factors affecting HupA production under SSF were optimized using response surface methodology.• The final HupA production was intensified following exposure to gamma radiation recording 1327 μg g^-1, which represents a 12.85-fold increase.

Molecular identification and evaluation of gamma irradiation effect on modulating heavy metals tolerance in some of novel endophytic fungal strains

Heavy metal (HM) pollution is a worldwide environmental issue. Given the urgent need to develop more powerful approaches for effective phytoremediation of HMs, isolation of novel endophytic strains from hyperaccumulator plants having potent HM tolerance is the main objective in this research. Moreover, the recovered strains were characterized and subjected to radiation mutagenesis to enhance their tolerance to HMs. Among 105 isolates, Alternaria alternata AUMC14431 was identified as the most effective Cd⁺² tolerant strain having high recorded tolerance index (TI) (76.24%); in addition, the recorded minimum inhibitory concentration (MIC) was 300 ppm. Meanwhile, Chaetomium globosum AUMC14432 was identified as the most effective Pb⁺² and Ni⁺² tolerant strain having high recorded TI (97.46 and 93.34%, respectively); in addition, the evaluated MICs were 250 and 200 ppm, respectively. UV and gamma irradiation of the tested strains enhanced their Cd⁺² and Pb⁺² tolerance significantly (P ≤ 0.05). Meanwhile, irradiation had a negative impact on Ni⁺² tolerance of C. globosum. The mutation incidence at the molecular level arising from exposure to irradiation was investigated. Genomic DNA of both the wild and mutated endophytic strains were isolated followed by random amplified polymorphic DNA (RAPD-PCR) analysis, using two short primers. A remarkable difference in DNA gel pattern between the wild type and mutated strains was observed. In conclusion, the novel isolated and irradiated endophytic strains, A. alternata S5 and C. globosum El26, having high efficiency in Cd⁺² and Pb⁺² tolerance, respectively, are considered to be prospective and powerful bioremediation candidates for potential application in microbially assisted phytoremediation.

Fermentation Strategies for Production of Pharmaceutical Terpenoids in Engineered Yeast

Terpenoids, also known as isoprenoids, are a broad and diverse class of plant natural products with significant industrial and pharmaceutical importance. Many of these natural products have antitumor, anti-inflammatory, antibacterial, antiviral, and antimalarial effects, support transdermal absorption, prevent and treat cardiovascular diseases, and have hypoglycemic activities. Production of these compounds are generally carried out through extraction from their natural sources or chemical synthesis. However, these processes are generally unsustainable, produce low yield, and result in wasting of substantial resources, most of them limited. Microbial production of terpenoids provides a sustainable and environment-friendly alternative. In recent years, the yeast Saccharomyces cerevisiae has become a suitable cell factory for industrial terpenoid biosynthesis due to developments in omics studies (genomics, transcriptomics, metabolomics, proteomics), and mathematical modeling. Besides that, fermentation development has a significant importance on achieving high titer, yield, and productivity (TYP) of these compounds. Up to now, there have been many studies and reviews reporting metabolic strategies for terpene biosynthesis. However, fermentation strategies have not been yet comprehensively discussed in the literature. This review summarizes recent studies of recombinant production of pharmaceutically important terpenoids by engineered yeast, S. cerevisiae, with special focus on fermentation strategies to increase TYP in order to meet industrial demands to feed the pharmaceutical market. Factors affecting recombinant terpenoids production are reviewed (strain design and fermentation parameters) and types of fermentation process (batch, fed-batch, and continuous) are discussed.

Novel mycosynthesis of Co3O4, CuO, Fe3O4, NiO, and ZnO nanoparticles by the endophytic Aspergillus terreus and evaluation of their antioxidant and antimicrobial activities

Several fungal endophytes were isolated and screened for their ability to biosynthesize a variety of nanoparticles (NPs), as a potentially simple and eco-friendly method with low cost. Among these fungi, a promising isolate named ORG-1 was found able to synthesize five different NPs types: Co₃O₄NPs, CuONPs, Fe₃O₄NPs, NiONPs, and ZnONPs. The ORG-1 strain was identified as Aspergillus terreus according to the morphological and molecular studies. Synthesis of these NPs was initially monitored by UV-Vis spectroscopy and further characterized by Fourier transform infrared spectroscopy. X-ray diffraction patterns revealed their crystalline structure. Dynamic light scattering analysis was applied to study the particle size distribution and stability. Transmission electron microscope studies indicated the morphology of the synthesized NPs. Additionally, the biological activities of the in vitro antioxidant and antimicrobial potentials were evaluated. Co₃O₄NPs, CuONPs, Fe₃O₄NPs, NiONPs, and ZnONPs showed promising antioxidant activity with 50% inhibitory concentrations of 85.44, 96.74, 102.41, 87.41, and 108.67 μg mL^-1, respectively. The synthesized NPs exhibited potent antimicrobial activities against several plant and human pathogens. To our knowledge, this is the first report on the use of one microbial strain for the synthesis of a variety of NPs. This study suggests endophytic fungi as new and alternate platforms with an exceptional potentiality for the synthesis of NPs with promising activities. KEY POINTS: • Discovery of a promising endophytic fungus for synthesis of five different types of NPs. • Mycosynthesis and characterization of all the synthesized NPs were investigated. • The synthesized NPs showed promising antioxidant and antimicrobial activities.

Alginate-based hydrogels for cancer therapy and research

Cancer is a major health issue concerning to all of us. Current treatment options are still limited due to not-selective action. Encapsulation is contemplated as an innovative approach to address systemic toxicity and tumor resistance caused by traditional therapies, while increasing encapsulated compounds bioavailability. The coating material of capsules strongly determines the success of the system. Since alginate has been proved non-toxic, biocompatible and biodegradable, it is considered a potential vehicle for therapeutic factors encapsulation. Besides, it has the particular ability to form hydrogels, which hold a high-water content and greatly resemble to natural soft tissues. The present review exposes the state-of-the-art and the most sophisticated alginate-based systems for cancer therapy and research. It begins with an overview of alginate hydrogels and the qualities that make them especially suitable for biomedical applications. In the following section, the application of alginate hydrogels as pioneering strategies for cancer treatment is described. Several examples of alginate-based delivery systems of therapeutic drugs, proteins and nucleic acids are provided. Significant emphasis is placed in both oral delivery systems and colorectal cancer therapy. Moreover, the role of alginate 3-D scaffolds for both cell culture and delivery is explained. Lastly, other applications of alginate-based hydrogels such as tumor biomarkers immunosensing and fluorescent surgical marker are included.

Response surface methodology-mediated improvement of the irradiated endophytic fungal strain, Alternaria brassicae AGF041 for Huperzine A-hyperproduction

Huperzine A (HupA) is an anti-Alzheimer's therapeutic and a dietary supplement for memory boosting that is extracted mainly from Huperziacae plants. Endophytes represent the upcoming refuge to protect the plant resource from distinction but their HupA yield is still far from commercialization. In this context, UV and gamma radiation mutagenesis of the newly isolated HupA-producing Alternaria brassicae AGF041 would be applied in this study for improving the endophytic HupA yield. Compared to non-irradiated cultures, UV (30-40 min, exposure) and γ (0·5 KGy, dose) irradiated cultures, each separately, showed a significant higher HupA yield (17·2 and 30·3%, respectively). While, application of a statistically optimized compound irradiation (0·70 KGy of γ treatment and 42·49 min of UV exposure, sequentially) via Response Surface Methodology (RSM) resulted in 53·1% production increase. Moreover, a stable selected mutant strain CM003 underwent batch cultivation using a 6·6 l bioreactor for the first time and was successful for scaling up the HupA production to 261·6 µg l^-1 . Findings of this research are demonstrated to be valuable as the employed batch fermentation represents a successful starting step towards the promising endophytic HupA production at an industrial scale.

Plant-Derived Natural Products in Cancer Research: Extraction, Mechanism of Action, and Drug Formulation

Cancer is one of the main causes of death globally and considered as a major challenge for the public health system. The high toxicity and the lack of selectivity of conventional anticancer therapies make the search for alternative treatments a priority. In this review, we describe the main plant-derived natural products used as anticancer agents. Natural sources, extraction methods, anticancer mechanisms, clinical studies, and pharmaceutical formulation are discussed in this review. Studies covered by this review should provide a solid foundation for researchers and physicians to enhance basic and clinical research on developing alternative anticancer therapies.

Microbial acetylcholinesterase inhibitors for Alzheimer's therapy: recent trends on extraction, detection, irradiation-assisted production improvement and nano-structured drug delivery

Abstract

Neurodegenerative disorders especially Alzheimer’s disease (AD) are significantly threatening the public health. Acetylcholinesterase (AChE) inhibitors are compounds of great interest which can be used as effective agents for the symptomatic treatment of AD. Although plants are considered the largest source for these types of inhibitors, the microbial production of AChE inhibitors represents an efficient, easily manipulated, eco-friendly, cost-effective, and alternative approach. This review highlights the recent advances on the microbial production of AChE inhibitors and summarizes all the previously reported successful studies on isolation, screening, extraction, and detecting methodologies of AChE inhibitors from the microbial fermentation, from the earliest trials to the most promising anti-AD drug, huperzine A (HupA). In addition, improvement strategies for maximizing the industrial production of AChE inhibitors by microbes will be discussed. Finally, the promising applications of nano-material-based drug delivery systems for natural AChE inhibitor (HupA) will also be summarized.

Key Points

• AChE inhibitors are potential therapies for Alzheimer’s disease.

• Microorganisms as alternate sources for prospective production of such inhibitors.

• Research advances on extraction, detection, and strategies for production improvement.

• Nanotechnology-based approaches for an effective drug delivery for Alzheimer’s disease.