scholarly journals Biosynthesis of components with antifungal activity against Aspergillus spp. using Streptomyces hygroscopicus

2015 ◽  
Vol 69 (2) ◽  
pp. 201-208
Author(s):  
Jelena Dodic ◽  
Zorana Roncevic ◽  
Jovana Grahovac ◽  
Bojana Bajic ◽  
Olivera Korolija

Losses of apple fruit during storage are mainly caused by fungal phytopathogens. Traditionally, postharvest fungal disease is controlled by the application of synthetic fungicides. However, the harmful impact on environment as well as human health largely limits their application. To reduce these problems in agrochemicals usage, new compounds for plant protection, which are eco-friendly, should be developed. The aim of this study is optimization of medium composition in terms of glucose, soybean meal and phosphates content, by applying response surface methodology, for the production of agents with antifungal activity against Aspergillus spp. For biosynthesis was used strain of Streptomyces hygroscopicus isolated from the environment. Experiments were carried out in accordance with Box-Behnken design with three factors on three levels and three repetitions in the central point. Antifungal activity of the obtained cultivation mediums against Aspergillus oryzae and Aspergillus niger was determined, in vitro, using the diffusion - disc method. For determination optimal medium components desirability function was used. Achieved model predicts that the maximum inhibition zone diameter (40.93 mm) against test microorganisms is produced when the initial content of glucose, soybean meal and phosphates are 47.77 g/l, 24.54 g/l and 0.98 g/l, respectively. To minimize the consumption of medium components and costs of effluents processing, additional three sets of optimization were made. The chosen method for optimization of medium components was efficient, relatively simple and time and material saving. Obtained results can be used for the further techno-economic analysis of the process to select optimal medium composition for industrial application.

2018 ◽  
Vol 22 ◽  
pp. 216-221
Author(s):  
O. V. Bulko ◽  
L. G. Lioshina

Aim. Micropropagation of Jacob’s ladder Polemonium caeruleum L. and black salsify Scorzonera hispanica L., obtaining root culture and regenerated plants. Methods. In vitro plant cultivation, medium composition modification for micropropagation, inoculation of explants with agrobacterial strains. Results. In vitro cultures of Jacob’s ladder and black salsify have been obtained, the optimal medium composition has been determined for the effective plants multiplication, rooting and growth, root cultures and regenerated plants of studied species have been obtained. Conclusions. Obtained technology of in vitro culture establishment of P. caeruleum and S. hispanica can be used for plants microclonal propagation so as root culture and regenerated plants acquiring due to the agrobacterial transformation – for further studies of secondary metabolism of these plants. Keywords: P. caeruleum L., S. hispanica L., micropropagation, phytohormones, root culture.


2006 ◽  
Vol 84 (7) ◽  
pp. 1043-1051 ◽  
Author(s):  
Piippa R. Wäli ◽  
Marjo Helander ◽  
Oiva Nissinen ◽  
Kari Saikkonen

Neotyphodium endophytes are suggested to be mutualistic symbionts of grasses and regarded as potential biological plant protection agents. We examined the effects of the Neotyphodium endophyte of meadow ryegrass on snow molds in vitro with dual cultures of endophyte and Typhula ishikariensis , and on grass–snow mold interactions in vivo in a greenhouse and in a field experiment. In dual cultures, the endophytes formed an inhibition zone and retarded the growth of T. ishikariensis. In the field experiment, however, the endophyte-infected (E+) meadow ryegrasses were more susceptible to T. ishikariensis than the endophyte-free (E–) grasses. Endophyte infection increased the winter damage of grasses both in greenhouse and in field conditions. After winter, the growth of E+ grasses exceeded the growth of E– plants in the field experiment, indicating the marked tolerance of E+ grasses against winter damage. We detected differences in growth and pathogenesis between the different T. ishikariensis strains and found meadow ryegrass cultivar–endophyte status interaction in the growth of meadow ryegrasses, which highlight the effects of the genetic background of the participants on endophyte–grass–snow mold interactions.


Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1430 ◽  
Author(s):  
Lina Šernaitė ◽  
Neringa Rasiukevičiūtė ◽  
Alma Valiuškaitė

Sustainable plant protection can be applied on apples against fungal pathogens such as Botrytis cinerea (which is responsible for gray mold)—a significant global postharvest disease. This pathogen can affect a wide range of hosts; and fruits may have variable susceptibilities to B. cinerea from different plant hosts. New possibilities to control gray mold in food production are under demand due to the emergence of resistance against antifungal agents in fungal pathogens. Cinnamon, pimento, and laurel extracts were previously assessed for antifungal activities under in vitro conditions and were found to have the potential to be effective against postharvest gray mold. Therefore, this study aimed to investigate the antifungal activity of cinnamon, pimento, and laurel extracts in vitro and against postharvest gray mold on apples to determine the susceptibility of apple fruits to B. cinerea from different plant hosts, and to analyze the chemical composition of the extracts. Apples (cv. “Connell Red”) were treated with different concentrations of extracts and inoculated with B. cinerea isolates from apple and strawberry followed by evaluation of in vitro antifungal activity. The results reveal that most of the concentrations of the extracts that were investigated were not efficient enough when assessed in the postharvest assay, despite having demonstrated a high in vitro antifungal effect. Apples were less susceptible to B. cinerea isolated from strawberry. To conclude, cinnamon extract was found to be the most effective against apple gray mold; however, higher concentrations of the extracts are required for the efficient inhibition of B. cinerea in fruits during storage.


2018 ◽  
Vol 33 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Zorana Roncevic ◽  
Ivana Pajcin ◽  
Dragoljub Cvetkovic ◽  
Sinisa Dodic ◽  
Jovana Grahovac ◽  
...  

Biological control is one of the best alternatives to pesticides as it avoids their weak points in plant disease control. In this study, the composition of cultivation medium for production of bioactive compounds by Bacillus subtilis ATCC 6633 was optimized. The produced bioactive compounds were tested against a phytopathogenic Penicillium sp. known for infesting different agricultural products and causing substantial crop losses. Antimicrobial activity assaying was carried out using the diffusion-disc method, and inhibition zone diameters were measured as direct indicators of antifungal activity. The response surface methodology (RSM) was used to evaluate the effects of different contents of initial nutrients (glycerol, NaNO2 and K2HPO4) in cultivation medium on inhibition zone diameter. Optimization was carried out using the desirability function method in order to maximize bioactive compounds yield and to minimize residual nutrients contents. The optimized concentrations of the selected nutrients in cultivation medium for production of bioactive compounds were: glycerol 20 g/l, NaNO2 1 g/l and K2HPO4 15 g/l.


2021 ◽  
Author(s):  
Bingyu Yan ◽  
Wen Gao ◽  
Li Tian ◽  
Shuai Wang ◽  
Huijun Dong

Abstract Objective To enhance the production of A40926 by implementing a strategy of the combination of genetically engineered strain construction and medium optimization. Results The engineered strain of Nonomuraea gerenzanensis presented an increment of 30.6 percent in A40926 production compared with that of the parent strain. Subsequently, an assembling medium, which was defined as M9 medium and mainly comprised glucose, maltodextrin, soybean meal, peptone, L-valine, and other inorganic salts, was determined as the optimal medium among the tested nine media. The optimum concentration of medium components was glucose 10 g/l, maltodextrin 37.9 g/l, soybean meal 34.5 g/l, peptone 30.0 g/l, and L-valine 4.3 g/l, respectively. The optimized medium was verified experimentally, and A40926 yield increased significantly from 257 mg/l to 332 mg/l, as compared to the non-optimized medium. The strategy brought a significant increase of A40926 yield by 65.2 percent. Conclusions The engineered mutant with the genetic attributes of the co-expression of the dbv3 and dbv20 genes and the deletion of the dbv23 gene could obviously enhance the production of A40926. In addition, the optimization of medium was an effective and essential tool for the improvement of the secondary metabolites in Actinomyces.


Author(s):  
Noura Berakdar ◽  
Abdulkarim Radwan

The main goal of this study was to investigate the antifungal activity of clove oil against candida albicans of vaginal candidiasis in females from Syria. An in vitro study was carried out using the following Candida albicans strains involved in vaginal candidiasis using the well diffusion (WD) testing.Candida albicans (ATCC 90028) and 15 strains were compiled from Aleppo University Hospital. These strains were collected from women having vaginal candidiasis. The antifungal activity of clove oil was determined in the form of inhibition zone using antifungal assay by agar WD testing.In all experiments, the obtained results indicated that clove oil has inhibitory effects on Candida albicans (ATCC 90028) and against15 fungal strains. This study showed that clove oil was active against the tested Candida albicans strains. Clove oil was more effective against Candida albicans compared to the antifungal antibiotics nystatin, ketoconazole and itraconazol. Clove oil may have potential for use in the development of clinically useful antifungal preparations. Therefore, clove oil might be clinically effective in the natural prevention treatment of vaginal candidiasis.       


Marine Drugs ◽  
2018 ◽  
Vol 16 (10) ◽  
pp. 380
Author(s):  
Jingjing Zhang ◽  
Fang Luan ◽  
Qing Li ◽  
Guodong Gu ◽  
Fang Dong ◽  
...  

Chemical modification is one of the most effective methods to improve the biological activity of chitin. In the current study, we modified C3-OH and C6-OH of chitin (CT) and successfully synthesized 6-amino-chitin (NCT) and 3,6-diamino-chitin (DNCT) through a series of chemical reactions. The structure of NCT and DNCT were characterized by elemental analyses, FT-IR, 13C NMR, XRD, and SEM. The inhibitory effects of CT, NCT, and DNCT against six kinds of phytopathogen (F. oxysporum f. sp. cucumerium, B. cinerea, C. lagenarium, P. asparagi, F. oxysporum f. niveum, and G. zeae) were evaluated using disk diffusion method in vitro. Meanwhile, carbendazim and amphotericin B were used as positive controls. Results revealed that 6-amino-chitin (NCT) and 3,6-diamino-chitin (DNCT) showed improved antifungal properties compared with pristine chitin. Moreover, DNCT exhibited the better antifungal property than NCT. Especially, while the inhibition zone diameters of NCT are ranged from 11.2 to 16.3 mm, DNCT are about 11.4–20.4 mm. These data demonstrated that the introduction of amino group into chitin derivatives could be key to increasing the antifungal activity of such compounds, and the greater the number of amino groups in the chitin derivatives, the better their antifungal activity was.


Pharmaceutics ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 75
Author(s):  
Lavinia Vlaia ◽  
Ioana Olariu ◽  
Ana Maria Muţ ◽  
Georgeta Coneac ◽  
Vicenţiu Vlaia ◽  
...  

Biocompatible gel microemulsions containing natural origin excipients are promising nanocarrier systems for the safe and effective topical application of hydrophobic drugs, including antifungals. Recently, to improve fluconazole skin permeation, tolerability and therapeutic efficacy, we developed topical biocompatible microemulsions based on cinnamon, oregano or clove essential oil (CIN, ORG or CLV) as the oil phase and sucrose laurate (D1216) or sucrose palmitate (D1616) as surfactants, excipients also possessing intrinsic antifungal activity. To follow up this research, this study aimed to improve the adhesiveness of respective fluconazole microemulsions using chitosan (a biopolymer with intrinsic antifungal activity) as gellator and to evaluate the formulation variables’ effect (composition and concentration of essential oil, sucrose ester structure) on the gel microemulsions’ (MEGELs) properties. All MEGELs were evaluated for drug content, pH, rheological behavior, viscosity, spreadability, in vitro drug release and skin permeation and antifungal activity. The results showed that formulation variables determined distinctive changes in the MEGELs’ properties, which were nevertheless in accordance with official requirements for semisolid preparations. The highest flux and release rate values and large diameters of the fungal growth inhibition zone were produced by formulations MEGEL-FZ-D1616-CIN 10%, MEGEL-FZ-D1216-CIN 10% and MEGEL-FZ-D1616-ORG 10%. In conclusion, these MEGELs were demonstrated to be effective platforms for fluconazole topical delivery.


Author(s):  
Hassan Thoulfikar A. Alamir ◽  
M. E. L. A. Shayoub ◽  
Wisal G. Abdalla ◽  
Eltayeb Suliman Elamin

In vitro activity of miconazole, salicylic acid and benzoic acid against T.richophyton mentagrophytes was done on Sabouraud’s dextrose agar. The inhibition zones were measured in cm. 2.8 cm, 1.5 cm and no inhibition zone were reported for miconazole, salicylic acid and benzoic acid respectively. Synergistic effect of salicylic acid and benzoic acid against T. mentagrophytes was done using two different bases of cream lanette 20% and aqueous cream 30/70. Four different formula each one contain 2% miconazole with different concentrations of salicylic acid and benzoic acid were used. Biggest inhibition zone (5 cm) was observed of lanette cream which contains 2% miconazole, 3% salicylic acid and 6% benzoic acid.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Chirayu Sa-uth ◽  
Paweena Rattanasena ◽  
Angsumarn Chandrapatya ◽  
Prapassorn Bussaman

Xenorhabdus stockiaePB09 bacterium has been shown to exhibit antifungal activity against several plant pathogens. To improve its efficacy, the optimization of the nutritional components in culture media was performed. The medium components that have significant effects on antifungal activity ofX. stockiaePB09 were initially identified using a fractional factorial design. Response surface methodology and central composite design were then used to create a model for optimizing the levels of carbon, nitrogen, and mineral sources that maximize antifungal activity ofX. stockiaePB09. After that, the suitable carbon, nitrogen, and mineral sources were selected and adjusted by the second-order polynomial regression model, which predicted that 98.62% of antifungal activity could be obtained when the medium contained sucrose, yeast extract, NaCl, and K2HPO4at 3.24, 23.71, 5.46, and 2.73 g/L, respectively. Laboratory verification of this recipe resulted in the antifungal activity at 97.95% in the shake flask experiment after 48-hour cultivation, which was significantly 27.22% higher than that obtained by using the TSB medium. In addition,X. stockiaePB09 cultured in the verified recipe by using 5 L fermenter could effectively inhibit the mycelial growth ofPhytophthorasp.,Rhizoctonia solani,Pythiumsp., andFusarium oxysporum. This study demonstrated that the RSM and CCD were shown to be valuable tools for optimizing the culture medium that maximize the antifungal activity ofX. stockiaePB09.


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