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Palacios-Rodriguez AP, Espinoza-Culupú A, Durán Y, Sánchez-Rojas T. Antimicrobial Activity of Bacillus amyloliquefaciens BS4 against Gram-Negative Pathogenic Bacteria. Antibiotics (Basel) 2024; 13:304. [PMID: 38666980 PMCID: PMC11047741 DOI: 10.3390/antibiotics13040304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/08/2024] [Accepted: 03/15/2024] [Indexed: 04/29/2024] Open
Abstract
Worldwide, bacterial resistance is one of the most severe public health problems. Currently, the failure of antibiotics to counteract superbugs highlights the need to search for new molecules with antimicrobial potential to combat them. The objective of this research was to evaluate the antimicrobial activity of Bacillus amyloliquefaciens BS4 against Gram-negative bacteria. Thirty yeasts and thirty-two Bacillus isolates were tested following the agar well-diffusion method. Four Bacillus sp. strains (BS3, BS4, BS17, and BS21) showed antagonistic activity against E. coli ATCC 25922 using bacterial culture (BC) and the cell-free supernatant (CFS), where the BS4 strain stood out, showing inhibitory values of 20.50 ± 0.70 mm and 19.67 ± 0.58 mm for BC and CFS, respectively. The Bacillus sp. BS4 strain can produce antioxidant, non-hemolytic, and antimicrobial metabolites that exhibit activity against several microorganisms such as Salmonella enterica, Klebsiella pneumoniae, Shigella flexneri, Enterobacter aerogenes, Proteus vulgaris, Yersinia enterocolitica, Serratia marcescens, Aeromonas sp., Pseudomonas aeruginosa, Candida albicans, and Candida tropicalis. According to the characterization of the supernatant, the metabolites could be proteinaceous. The production of these metabolites is influenced by carbon and nitrogen sources. The most suitable medium to produce antimicrobial metabolites was TSB broth. The one-factor-at-a-time method was used to standardize parameters such as pH, agitation, temperature, carbon source, nitrogen source, and salts, resulting in the best conditions of pH 7, 150 rpm, 28 °C, starch (2.5 g/L), tryptone (20 g/L), and magnesium sulfate (0.2 g/L), respectively. Moreover, the co-culture was an excellent strategy to improve antimicrobial activity, achieving maximum antimicrobial activity with an inhibition zone of 21.85 ± 1.03 mm. These findings position the Bacillus amyloliquefaciens BS4 strain as a promising candidate for producing bioactive molecules with potential applications in human health.
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Affiliation(s)
- Ana Paula Palacios-Rodriguez
- Laboratory of Environmental Microbiology and Biotechnology, Faculty of Biological Sciences, Universidad Nacional Mayor de San Marcos, Lima 15081, Peru; (A.P.P.-R.); (Y.D.)
| | - Abraham Espinoza-Culupú
- Laboratory of Molecular Microbiology and Biotechnology, Faculty of Biological Sciences, Universidad Nacional Mayor de San Marcos, Lima 15081, Peru
| | - Yerson Durán
- Laboratory of Environmental Microbiology and Biotechnology, Faculty of Biological Sciences, Universidad Nacional Mayor de San Marcos, Lima 15081, Peru; (A.P.P.-R.); (Y.D.)
| | - Tito Sánchez-Rojas
- Laboratory of Environmental Microbiology and Biotechnology, Faculty of Biological Sciences, Universidad Nacional Mayor de San Marcos, Lima 15081, Peru; (A.P.P.-R.); (Y.D.)
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Duong NL, Nguyen VM, Tran TAN, Phan TDT, Tran TBY, Do BL, Phung Anh N, Nguyen TAT, Ho TGT, Nguyen T. Durian Shell-Mediated Simple Green Synthesis of Nanocopper against Plant Pathogenic Fungi. ACS OMEGA 2023; 8:10968-10979. [PMID: 37008095 PMCID: PMC10061525 DOI: 10.1021/acsomega.2c07559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 03/06/2023] [Indexed: 06/19/2023]
Abstract
The synthesis of fungicides in eco-friendly and cost-effective ways is significantly essential for agriculture. Plant pathogenic fungi cause many ecological and economic issues worldwide, which must be treated with effective fungicides. Here, this study proposes the biosynthesis of fungicides, which combines copper and Cu2O nanoparticles (Cu/Cu2O) synthesized using durian shell (DS) extract as a reducing agent in aqueous media. Sugar and polyphenol compounds contained in DS, as the main phytochemicals acting in the reduction procedure, were extracted under different temperatures and duration conditions to obtain the highest yields. We confirmed the extraction process performed at 70 °C for 60 min to be the most effective in extracting sugar (6.1 g/L) and polyphenols (22.7 mg/L). We determined the suitable conditions for Cu/Cu2O synthesis using a DS extract as a reducing agent for a synthesis time of 90 min, a volume ratio of DR extract/Cu2+ of 15:35, an initial pH solution of 10, a synthesis temperature of 70 °C, and a CuSO4 concentration of 10 mM. The characterization results of as-prepared Cu/Cu2O NP showed a highly crystalline structure of Cu2O and Cu with sizes estimated in the range of 40-25 nm and 25-30 nm, respectively. Through in vitro experiments, the antifungal efficacy of Cu/Cu2O against Corynespora cassiicola and Neoscytalidium dimidiatum was investigated by the inhibition zone. The green-synthesized Cu/Cu2O nanocomposites, which are potential antifungals against plant pathogens, exhibited excellent antifungal efficacy against both Corynespora cassiicola (MIC = 0.25 g/L, the diameter of the inhibition zone was 22.00 ± 0.52 mm) and Neoscytalidium dimidiatum (MIC = 0.0625 g/L, the diameter of the inhibition zone was 18.00 ± 0.58 mm). Cu/Cu2O nanocomosites prepared in this study could be a valuable suggestion for the control of plant pathogenic fungi affecting crop species globally.
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Affiliation(s)
- Nhat Linh Duong
- Ho
Chi Minh City Open University, 97 Vo Van Tan Str., District 3, Ho Chi Minh City 700000, Vietnam
| | - Van Minh Nguyen
- Ho
Chi Minh City Open University, 97 Vo Van Tan Str., District 3, Ho Chi Minh City 700000, Vietnam
| | - Thi A Ni Tran
- MIDOLI
Company Limited, Second
Floor, 02-04 Alexandre de Rhodes, Ben Nghe, District 1, Ho Chi Minh City 700000, Vietnam
| | - Thi Diem Trinh Phan
- Ho
Chi Minh City Open University, 97 Vo Van Tan Str., District 3, Ho Chi Minh City 700000, Vietnam
| | - Thi Bao Yen Tran
- Ho
Chi Minh City Open University, 97 Vo Van Tan Str., District 3, Ho Chi Minh City 700000, Vietnam
| | - Ba Long Do
- Institute
of Chemical Technology, Vietnam Academy
of Science and Technology, No. 1A, TL29 Str., Thanh Loc Ward, District 12, Ho Chi Minh City 700000, Vietnam
| | - Nguyen Phung Anh
- Institute
of Chemical Technology, Vietnam Academy
of Science and Technology, No. 1A, TL29 Str., Thanh Loc Ward, District 12, Ho Chi Minh City 700000, Vietnam
| | - Thi Anh Thu Nguyen
- Tra
Vinh University, 126 Nguyen Thien Thanh, Tra Vinh City 87000, Vietnam
| | - Thanh Gia-Thien Ho
- Institute
of Chemical Technology, Vietnam Academy
of Science and Technology, No. 1A, TL29 Str., Thanh Loc Ward, District 12, Ho Chi Minh City 700000, Vietnam
| | - Tri Nguyen
- Ho
Chi Minh City Open University, 97 Vo Van Tan Str., District 3, Ho Chi Minh City 700000, Vietnam
- Institute
of Chemical Technology, Vietnam Academy
of Science and Technology, No. 1A, TL29 Str., Thanh Loc Ward, District 12, Ho Chi Minh City 700000, Vietnam
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Chen J, Lan X, Jia R, Hu L, Wang Y. Response Surface Methodology (RSM) Mediated Optimization of Medium Components for Mycelial Growth and Metabolites Production of Streptomyces alfalfae XN-04. Microorganisms 2022; 10:microorganisms10091854. [PMID: 36144456 PMCID: PMC9501596 DOI: 10.3390/microorganisms10091854] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/09/2022] [Accepted: 09/13/2022] [Indexed: 11/29/2022] Open
Abstract
Streptomyces alfalfae XN-04 has been reported for the production of antifungal metabolites effectively to control Fusarium wilt of cotton, caused by Fusarium oxysporum f. sp. vasinfectum (Fov). In this study, we used integrated statistical experimental design methods to investigate the optimized liquid fermentation medium components of XN-04, which can significantly increase the antifungal activity and biomass of XN-04. Seven variables, including soluble starch, KNO3, soybean cake powder, K2HPO4, MgSO4·7H2O, CaCO3 and FeSO4·7H2O, were identified as the best ingredients based on one-factor-at-a-time (OFAT) method. The results of Plackett–Burman Design (PBD) showed that soluble starch, soybean cake powder and K2HPO4 were the most significant variables among the seven variables. The steepest climbing experiment and response surface methodology (RSM) were performed to determine the interactions among these three variables and fine-tune the concentrations. The optimal compositions of medium were as follows: soluble starch (26.26 g/L), KNO3 (1.00 g/L), soybean cake powder (23.54 g/L), K2HPO4 (0.27 g/L), MgSO4·7H2O (0.50 g/L), CaCO3 (1.00 g/L) and FeSO4·7H2O (0.10 g/L). A verification experiment was then carried out under the optimized conditions, and the results revealed the mycelial dry weight of S. alfalfae XN-04 reaching 6.61 g/L. Compared with the initial medium, a 7.47-fold increase in the biomass was achieved using the optimized medium. Moreover, the active ingredient was purified from the methanol extract of S. alfalfae XN-04 mycelium and then identified as roflamycoin (a polyene macrolide antibiotic). The results may provide new insights into the development of S. alfalfae XN-04 fermentation process and the control of the Fusarium wilt of cotton and other plant diseases.
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Affiliation(s)
| | | | | | | | - Yang Wang
- Correspondence: ; Tel.: +86-187-9280-9011
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Ni HJ, Lv SY, Sheng YT, Wang H, Chu XH, Zhang HW. Optimization of fermentation conditions and medium compositions for the production of chrysomycin a by a marine-derived strain Streptomyces sp. 891. Prep Biochem Biotechnol 2021; 51:998-1003. [PMID: 33600297 DOI: 10.1080/10826068.2021.1885046] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Chrysomycin A is one of the valuable drug leads used to treat infectious diseases such as tuberculosis and methicillin-resistant Staphylococcus aureus. In order to increase its yield, this work firstly focuses on optimization of fermentation conditions and medium compositions of a wild-type chrysomycin A-producing strain Streptomyces sp. 891 from marine sediment. By single-factor experiment, effects of fermentation conditions (fermentation time, seed age, initial pH, inoculum amount, liquid loading, shaking speed) and medium composition (carbon sources, nitrogen sources, inorganic salts) on the yield of chrysomycin A were carefully evaluated and analyzed followed by optimization at shake-flask level. The results indicated its optimal fermentation conditions for producing chrysomycin A were as follows: fermentation time 168 h, seed age 48 h, initial pH 6.5, inoculum amount 5.0%, liquid loading 30 mL in 250-mL Erlenmeyer flask and shaking speed 220 rpm. By orthogonal test, the optimal fermentation medium constitutes 40 g/L glucose, 20 g/L corn starch, 25 g/L hot-pressed soybean flour, 3 g/L CaCO3. Verification tests suggested the yield of chrysomycin A under optimized conditions reaches up to 3648 ± 119 mg/L, which is increased by almost 5 times. These findings definitely pave the way for scale-up preparation of chrysomycin A and application in the pharmaceutical industry.
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Affiliation(s)
- Hong-Jin Ni
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
| | - Sun-Yan Lv
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
| | - Ying-Tao Sheng
- Collaborative Innovation Center of Green Pharmaceutics of Delta Yangzi Region, Zhejiang University of Technology, Hangzhou, China
| | - Hong Wang
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
| | - Xiao-He Chu
- Collaborative Innovation Center of Green Pharmaceutics of Delta Yangzi Region, Zhejiang University of Technology, Hangzhou, China
| | - Hua-Wei Zhang
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
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Abdel-Shafi S, Al-Mohammadi AR, Almanaa TN, Moustafa AH, Saad TMM, Ghonemey AR, Anacarso I, Enan G, El-Gazzar N. Identification and Testing of Antidermatophytic Oxaborole-6-Benzene Sulphonamide Derivative (OXBS) from Streptomyces atrovirens KM192347 Isolated from Soil. Antibiotics (Basel) 2020; 9:antibiotics9040176. [PMID: 32294942 PMCID: PMC7235740 DOI: 10.3390/antibiotics9040176] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/04/2020] [Accepted: 04/09/2020] [Indexed: 12/18/2022] Open
Abstract
There is a need to continue research to find out other anti-dermatophytic agents to inhibit causal pathogenic skin diseases including many types of tinea. We undertook the production, purification, and identification of an anti-dermatophytic substance by Streptomyces atrovirens. Out of 103 streptomycete isolates tested, only 20 of them showed antidermatophytic activity with variable degrees against Trichophyton tonsurans CCASU 56400 (T. tonsurans), Microsporum canis CCASU 56402 (M. canis), and Trichophyton mentagrophytes CCASU 56404 (T. mentagrophytes). The most potent isolate, S10Q6, was identified based on the tests conducted that identified morphological and physiological characteristics and using 16S rRNA gene sequencing. The isolate was found to be closely correlated to previously described species Streptomyces atrovirens; it was designated Streptomyces atrovirens KM192347 (S. atrovirens). Maximum antifungal activity of the strain KM192347 was obtained in modified starch nitrate medium (MSNM) adjusted initially at pH 7.0 and incubated at 30 °C in shaken cultures (150 rpm) for seven days. The antifungal compound was purified by using two steps protocol including solvent extraction and column chromatography. The MIC of it was 20 µg/mL against the dermatophyte cultures tested. According to the data obtained from instrumental analysis and surveying the novel antibiotics database, the antidermatophytic substance produced by the strain KM192347 was characterized as an oxaborole-6-benzene sulphonamide derivative and designated oxaborole-6-benzene sulphonamide (OXBS) with the chemical formula C13H12 BNO4S. The crude OXBS didn’t show any toxicity on living cells. Finally, the results obtained herein described another anti-dermatophytic substance named an OXBS derivative.
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Affiliation(s)
- Seham Abdel-Shafi
- Department of Botany and Microbiology, Faculty of Science, Zagazig University, El-Sharqia 44519, Egypt;
- Correspondence: (S.A.-S.); (G.E.); Tel.: +20-1289600036 (S.A.-S.); +20-1009877015 (G.E.)
| | | | - Taghreed N. Almanaa
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11495, Saudi Arabia
| | - Ahmed H. Moustafa
- Department of Chemistry, Faculty of Science, Zagazig University, Zagazig 44519, Egypt;
| | | | | | - Immacolata Anacarso
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi, 41121 Modena, Italy;
| | - Gamal Enan
- Department of Botany and Microbiology, Faculty of Science, Zagazig University, El-Sharqia 44519, Egypt;
- Correspondence: (S.A.-S.); (G.E.); Tel.: +20-1289600036 (S.A.-S.); +20-1009877015 (G.E.)
| | - Nashwa El-Gazzar
- Department of Botany and Microbiology, Faculty of Science, Zagazig University, El-Sharqia 44519, Egypt;
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Djinni I, Defant A, Kecha M, Mancini I. Actinobacteria Derived from Algerian Ecosystems as a Prominent Source of Antimicrobial Molecules. Antibiotics (Basel) 2019; 8:E172. [PMID: 31581466 PMCID: PMC6963827 DOI: 10.3390/antibiotics8040172] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 09/25/2019] [Accepted: 09/25/2019] [Indexed: 01/19/2023] Open
Abstract
Actinobacteria, in particular "rare actinobacteria" isolated from extreme ecosystems, remain the most inexhaustible source of novel antimicrobials, offering a chance to discover new bioactive metabolites. This is the first overview on actinobacteria isolated in Algeria since 2002 to date with the aim to present their potential in producing bioactive secondary metabolites. Twenty-nine new species and one novel genus have been isolated, mainly from the Saharan soil and palm groves, where 37.93% of the most abundant genera belong to Saccharothrix and Actinopolyspora. Several of these strains were found to produce antibiotics and antifungal metabolites, including 17 new molecules among the 50 structures reported, and some of these antibacterial metabolites have shown interesting antitumor activities. A series of approaches used to enhance the production of bioactive compounds is also presented as the manipulation of culture media by both classical methods and modeling designs through statistical strategies and the associations with diverse organisms and strains. Focusing on the Algerian natural sources of antimicrobial metabolites, this work is a representative example of the potential of a closely combined study on biology and chemistry of natural products.
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Affiliation(s)
- Ibtissem Djinni
- Laboratoire de Microbiologie Appliquée, Faculté des Sciences de la Nature et de la Vie, Université de Bejaia 06000, Algeria.
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Trento 38123, Italy.
| | - Andrea Defant
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Trento 38123, Italy.
| | - Mouloud Kecha
- Laboratoire de Microbiologie Appliquée, Faculté des Sciences de la Nature et de la Vie, Université de Bejaia 06000, Algeria.
| | - Ines Mancini
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Trento 38123, Italy.
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Jacob J, Rajendran RU, Priya SH, Purushothaman J, Saraswathy Amma DKBN. Enhanced antibacterial metabolite production through the application of statistical methodologies by a Streptomyces nogalater NIIST A30 isolated from Western Ghats forest soil. PLoS One 2017; 12:e0175919. [PMID: 28437452 PMCID: PMC5402949 DOI: 10.1371/journal.pone.0175919] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 03/14/2017] [Indexed: 11/22/2022] Open
Abstract
Streptomyces strains isolated from Nelliyampathy forest soil of Western Ghats, Kerala, India were evaluated for their antibacterial efficacy against two indicator pathogenic bacteria (Escherichia coli and Staphylococcus aureus). Among 140 strains tested, sixteen recorded potent antibacterial properties and were further screened against eleven bacterial pathogens. A strain identified as Streptomyces nogalater and designated as NIIST A30 exhibited maximum inhibition against all the test pathogens. Among the eight fermentation media tested, inorganic salts starch broth recorded the best for antibacterial production. The ethyl acetate crude extract exhibited antioxidant properties with IC50 value of 30 μg/mL and had no cytotoxicity towards L6, H9c2 and RAW 264.7 cell lines up to a concentration of 50 μg/mL. Maximum metabolite production was achieved in pH 7.0 at 35°C after 7 days incubation. The significant media components for maximum metabolite production were optimized through response surface methodology employing Plackett-Burman and Box-Behnken designs. The composition of the final optimized medium was soluble starch, 14.97g; (NH4)2SO4, 2.89g; K2HPO4, 2.07g; MgSO4.7H2O, 1g; NaCl, 1g, CaCO3, 2g; FeSO4.7H2O, 1mg; MnCl2.7H2O, 1mg; and ZnSO4.7H2O, 1mg per litre of distilled water. The optimization resulted an antibacterial activity of 28±1.5mm against S. epidermidis which was in close accordance with the predicted value of 30 mm. It is also evident from the result that an increase of 86.66% antibacterial production was recorded in optimized media. The chosen method was economical, efficient and useful for future antibacterial drug discovery from a broad spectrum metabolite producer like Streptomyces nogalater NIIST A30.
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Affiliation(s)
- Jubi Jacob
- Agro- Processing and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram, Kerala, India
- Academy of Scientific and Innovative Research (AcSIR),CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram, Kerala, India
| | - Reshma Uma Rajendran
- Agro- Processing and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram, Kerala, India
| | - Syama Hari Priya
- Agro- Processing and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram, Kerala, India
| | - Jayamurthy Purushothaman
- Agro- Processing and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram, Kerala, India
- Academy of Scientific and Innovative Research (AcSIR),CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram, Kerala, India
| | - Dileep Kumar Bhaskaran Nair Saraswathy Amma
- Agro- Processing and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram, Kerala, India
- Academy of Scientific and Innovative Research (AcSIR),CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram, Kerala, India
- * E-mail:
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Optimization of antifungal production by an alkaliphilic and halotolerant actinomycete, Streptomyces sp. SY-BS5, using response surface methodology. J Mycol Med 2015; 25:108-15. [PMID: 25703134 DOI: 10.1016/j.mycmed.2014.12.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 12/20/2014] [Accepted: 12/31/2014] [Indexed: 11/21/2022]
Abstract
OBJECTIVE Optimization of medium components and physicochemical parameters for antifungal production by an alkaliphilic and salt-tolerant actinomycete designated Streptomyces sp. SY-BS5; isolated from an arid region in south of Algeria. MATERIALS AND METHODS The strain showed broad-spectrum activity against pathogenic and toxinogenic fungi. Identification of the actinomycete strain was realized on the basis of 16S rRNA gene sequencing. Antifungal production was optimized following one-factor-at-a-time (OFAT) and response surface methodology (RSM) approaches. The most suitable medium for growth and antifungal production was found using one-factor-at-a-time methodology. The individual and interaction effects of three nutritional variables, carbon source (glucose), nitrogen source (yeast extract) and sodium chloride (NaCl) were optimized by Box-Behnken design. Finally, culture conditions for the antifungal production, pH and temperature were studied and determined. RESULTS Analysis of the 16S rRNA gene sequence (1454 nucleotides) assigned this strain to Streptomyces genus with 99% similarity with Streptomyces cyaneofuscatus JCM4364(T), the most closely related. The results of the optimization study show that concentrations 3.476g/L of glucose, 3.876g/L of yeast extract and 41.140g/L of NaCl are responsible for the enhancement of antifungal production by Streptomyces sp. SY-BS5. The preferable culture conditions for antifungal production were pH 10, temperature 30°C for 09 days. CONCLUSION This study proved that RSM is usual and powerful tool for the optimization of antifungal production from actinomycetes.
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