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Optimized Production of the Allylamine Antifungal “Terbinafine” by Lysinibacillus Isolate MK212927 Using Response Surface Methodology

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Optimized Production of the Allylamine Antifungal “Terbinafine” by Lysinibacillus Isolate MK212927 Using Response Surface Methodology Infection and Drug Resistance Dovepress open access to scientific and medical research Open Access Full Text Article ORIGINAL RESEARCH Optimized Production of the Allylamine Antifungal “Terbinafine” by Lysinibacillus Isolate MK212927 Using Response Surface Methodology This article was published in the following Dove Press journal: Infection and Drug Resistance Sayed E El-Sayed1 Purpose: We aimed to optimize the factors affecting the production of the allylamine Ghadir S El-Housseiny 2 antifungal, terbinafine, by Lysinibacillus isolate MK212927, a natural producer of this broad- Neveen A Abdelaziz 1 spectrum fungicidal compound. Mona R El-Ansary 3 Methods: We employed a central composite design to optimize the five most important Khaled M Aboshanab 2 variables influencing the production of terbinafine which were carbon source, nitrogen source, temperature, pH and agitation. 1 Department of Microbiology and Results: The optimum conditions were found to be starch 5 g/L, ammonium chloride 5 g/L, Immunology, Faculty of Pharmacy, Ahram Canadian University, Giza, Egypt; temperature 32°C, agitation 150 rpm and pH 7. The actual response (inhibition zone 2Department of Microbiology and diameter) was highly comparable to the value predicted by the model, indicating a valid Immunology, Faculty of Pharmacy, Ain model. Using the standard calibration curve of terbinafine, the optimized conditions resulted Shams University, Cairo 11566, Egypt; 3Department of Biochemistry, Modern in an increase in the antifungal metabolite production (terbinafine) by about 1.6-fold University for Technology and (1814.662 µg/mL compared to 1165.550 µg/mL under standardized conditions). Information (MTI), Cairo, Egypt Conclusion: This is the first report, to the best of our knowledge, on optimized production of terbinafine by Lysinibacillus species. Hence, these findings may be useful as baseline data for scaling up the production of terbinafine from a natural microbial source. Keywords: fungicidal, optimization, central composite design, terbinafine Introduction Invasive fungal infections (IFIs) have elevated consistently with the increase in at-risk immunocompromised patients, patients suffering from malignancies and those with severe illnesses. Most of these infections are caused by Candida and Aspergillus species.1,2 Twenty percent of the infections reported in intensive care unit (ICU) were attributed to invasive candidiasis.3 Oropharyngeal candidiasis remains the prominent opportunistic infection in HIV-positive patients with 95% of the cases caused by C. albicans.4 Increased resistance to antifungal agents such as azoles both in C. albicans and non-albicans Candida spp. is extensively reported.5 Aspergillus causes infections ranging from invasive aspergillosis (IA) to extreme complications. Huge Correspondence: Khaled M Aboshanab elevation in drug-resistant isolates of Aspergillus species poses an extra danger to Department of Microbiology and 6 Immunology, Faculty of Pharmacy, humans. The current pharmaceutical practices visualize fungi/yeast as a difficult chal­ Ain Shams University, Organization of lenge to common drugs. Not only do these drugs have adverse effects but also present African Unity St., Abbassia, Cairo 11566, Egypt regimes of antifungals are becoming gradually inefficient. Moreover, the capability of Tel +011201001547800 Candida sp. to form drug-resistant biofilm is a driving factor for fungal pathogenicity.7 Fax +01120224051107 Email [email protected] Indeed, there is an increased need for new drugs to treat fungal diseases in humans. submit your manuscript | www.dovepress.com Infection and Drug Resistance 2020:13 3613–3626 3613 DovePress © 2020 El-Sayed et al. This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms. http://doi.org/10.2147/IDR.S267590 php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (https://www.dovepress.com/terms.php). El-Sayed et al Dovepress Many bacterial species are recognized to produce anti­ Collection Ain Shams University (CCASU) belonging to fungal agents. Among the soil bacteria is Lysinibacillus the WDCM (strain number, CCASU-MK212927). The tar­ (gram-positive spore-forming rods) which was previously get strain used for testing the antifungal activity of the studied and known for its ability to produce antifungal produced metabolite was the standard strain Candida albi­ metabolites against plant pathogens.8–10 Recent studies cans ATCC 10231. reported that Lysinibacillus fusiformis displayed strong antifungal activity against aflatoxigenic Aspergillus flavus Fermentative Production of the 11 and Aspergillus parasiticus. Lysinibacillus isolate Antifungal Compound MK212927 is a novel bacterial isolate recovered through The seed culture was prepared by transferring a loopful a screening program and shown to produce a metabolite from a new culture of Lysinibacillus isolate MK212927 with promising antifungal activities against human fungal into a flask containing 50 mL trypticase soy broth and pathogens. Upon characterization and structure elucida­ incubated at 250 rpm and 30°C for 15–18 hours. One tion, it was found to be the allylamine antifungal (terbina­ milliliter of the culture obtained was then centrifuged for fine). The present study aimed to optimize the various 10 minutes at 16,000 rpm using a micro centrifuge factors affecting terbinafine production. Since many fac­ (Centurion Scientific-K240R) and the obtained cells were tors might affect the complexity of experimental results, washed once with 1 mL sterile normal saline and resus­ experimental design may be applied to perform data pended in the production media. The basal minimal med­ 12 optimization. Response surface methodology (RSM), ium used for the production of the antifungal metabolite a superior form of experimental design, can be defined as was prepared according to Singh et al18 and consisted of: a hybrid of both mathematical and statistical methods for 5g/L glucose, 6 g/L Na2HPO4, 3g/L K2HPO4, 1 g/L NH4 designing, developing, analysis and optimization of multi­ Cl, 0.5 g/L NaCl, 0.12 g/L MgSO4, 0.2 g/L CaCl2 and faceted processes.13 It simultaneously identifies the result distilled H2O to 1 liter. KOH pellets were used to adjust of altering different factors and their influence on the the pH to 7 before sterilization. 14,15 required outcome of a procedure. This method is Production was carried out by inoculating 30 mL aliquots more efficient than the traditional optimization method of of the basal medium (in 250 mL Erlenmeyer flasks) by the one-factor-at-a-time since it requires fewer trials, has the seed culture to give a final count of 1x 107cfu/mL and ability to investigate the interactive effects among the incubating in a shaking incubator at 150 rpm and 30°C. factors and avoids wasting unnecessary time and 16 materials. Response surface methodology is a very ben­ Estimation of Antifungal Concentration eficial tool to optimize numerous parameters, to find rela­ Antifungal concentrations were quantified from the linear tiveness among the factors, to find the best combination of equation of a standard calibration curve of terbinafine parameters and for prediction of responses. Several types (Lamisil®). To obtain a standard calibration curve we of designs are available for the optimization of important plotted known concentrations of terbinafine (Lamisil®) fermentation parameters, and central composite design obtained from NOVARTIS Pharmaceutical Company 17 (CCD) is one of the most useful ones. Therefore, the (Cairo, Egypt) versus the corresponding inhibition zone goal of this study was to optimize the various physical and diameters obtained against C. albicans ATCC 10231. environmental parameters using RSM for maximum pro­ duction of the terbinafine metabolite produced by Studying Different Factors Affecting Lysinibacillus isolate MK212927. Antifungal Production Time Course of Antifungal Production Materials and Methods To obtain the time required for maximum antifungal pro­ Microorganisms duction, seven Erlenmeyer flasks (250 mL) were prepared Lysinibacillus isolate MK212927 is a novel bacterial isolate as mentioned above. One flask was sampled on daily basis proven to be a natural producer of the allylamine antifungal for determination of maximum level of the antifungal terbinafine with broad-spectrum fungicidal activities. metabolite produced over an incubation period of 7 days. Lysinibacillus isolate MK212927 (NCBI GenBank acces­ In brief, one mL of the fermentation broth was centrifuged sion number, MK212927.1) was deposited in the Culture at 16,000 rpm and the supernatant (100 µL/well) was 3614 submit your manuscript | www.dovepress.com Infection and Drug Resistance 2020:13 DovePress Dovepress El-Sayed et al tested using the agar cup-plate method against Candida (Design Expert® Software, Stat-Ease Inc., Statistics Made albicans ATCC 10231 (0D= 0.1) in sabouraud`s dextrose Easy, Minneapolis, MN, USA). agar. The diameters of inhibition zones against Candida Confirmation of the RSM Optimization Results albicans ATCC 10231 were determined after
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