Enhanced antibiotic activity of Xenorhabdus nematophila by medium optimization

BackgroundThe production of secondary metabolites with antibiotic properties is a common characteristic to entomopathogenic bacteria Xenorhabdus spp. These metabolites not only have diverse chemical structures but also have a wide range of bioactivities with medicinal and agricultural interests such as antibiotic, antimycotic and insecticidal, nematicidal and antiulcer, antineoplastic and antiviral. It has been known that cultivation parameters are critical to the secondary metabolites produced by microorganisms. Even small changes in the culture medium may not only impact the quantity of certain compounds but also the general metabolic profile of microorganisms. Manipulating nutritional or environmental factors can promote the biosynthesis of secondary metabolites and thus facilitate the discovery of new natural products. This work was conducted to evaluate the influence of nutrition on the antibiotic production of X. bovienii YL002 and to optimize the medium to maximize its antibiotic production.ResultsNutrition has high influence on the antibiotic production of X. bovienii YL002. Glycerol and soytone were identified as the best carbon and nitrogen sources that significantly affected the antibiotic production using one-factor-at-a-time approach. Response surface methodology (RSM) was applied to optimize the medium constituents (glycerol, soytone and minerals) for the antibiotic production of X. bovienii YL002. Higher antibiotic activity (337.5 U/mL) was obtained after optimization. The optimal levels of medium components were (g/L): glycerol 6.90, soytone 25.17, MgSO4·7H2O 1.57, (NH4)2SO4 2.55, KH2PO4 0.87, K2HPO4 1.11 and Na2SO4 1.81. An overall of 37.8% increase in the antibiotic activity of X. bovienii YL002 was obtained compared with that of the original medium.ConclusionsTo the best of our knowledge, there are no reports on antibiotic production of X. boviebii by medium optimization using RSM. The results strongly support the use of RSM for medium optimization. The optimized medium not only resulted in a 37.8% increase of antibiotic activity, but also reduced the numbers of experiments. The chosen method of medium optimization was efficient, simple and less time consuming. This work will be useful for the development of X. bovienii cultivation process for efficient antibiotic production on a large scale, and for the development of more advanced control strategies on plant diseases.

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“…[19,27]. Hence, YSG medium was employed as an original medium for the carbon and nitrogen sources selection studies.…”

Section: Resultsmentioning

confidence: 99%

“…[27,31,32]. Based on YSG medium, the effect of various carbon and nitrogen sources on antibiotic activity of X. bovienii YL002 were studied by employing these at a final concentration of 5 g/L and 15 g/L for carbon and nitrogen sources, respectively.…”

Section: Resultsmentioning

confidence: 99%

Improvement of antibiotic activity of Xenorhabdus bovienii by medium optimization using response surface methodology

Wang

Fang

et al. 2011

Microb Cell Fact

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“…The bacterial isolates were plated on Nutrient Bromothymol Blue Agar (NBTA) medium (Akhurst 1980). On which Phase I is distinguished from Phase II by its adsorption of bromothymol blue to produce a red core colony overlaid by dark blue and surrounded by a clear zone after 3–4 days of incubation at 25 °C (Wang et al 2008). The NBTA medium contained 20 g nutrient agar (Difco), 25 mg bromothymol blue (s.d.…”

Section: Methodsmentioning

confidence: 99%

Molecular identification and genetic diversity among Photorhabdus and Xenorhabdus isolates

et al. 2017

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Five bacterial strains were isolated from the hemocoel of the greater wax moth larvae (Galleria mellonella) infected with the entomopathogenic nematodes: Heterorhabditis bacteriophora HP88, Heterorhabditis indicus RM1 and Heterorhabditis sp (S1), Steinernema abbasi and Steinernema sp. (S II). Strains were identified as Photorhabdus luminescens HRM1, P. luminescens HS1, P. luminescens HP88, Xenorhabdus indica and X. nematophila ATTC19061 using 16S rDNA sequence analysis. To reveal the genetic diversity among these strains, three molecular markers (RAPD, ISSR and SRAP) were employed. RAPD analysis showed 73.8 and 54.5 polymorphism percentages for the Photorhabdus and Xenorhabdus strains, respectively. ISSR analysis resulted in 70.1 and 75.2 polymorphism percentages among the Photorhabdus and Xenorhabdus strains, respectively. The SRAP analysis indicated that 75.6 and 61.2% genetic polymorphism was detected among Photorhabdus and Xenorhabdus strains, respectively. The cluster analysis grouped the three Photorhabdus strains together in one cluster and the two Xenorhabdus strains together in another cluster indicating the phylogenetic relationships among them. The genotype-specific markers detected from the three molecular markers (RAPD, ISSR and SRAP) were sufficient to distinguish between the different bacterial strains tested and can be used in the future IBM program that could be built on the use of these strains.

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“…Various media (Luria Broth, Nutrient Broth, YS, WYH media [13][14] were used to determine the optimal media and culture conditions for the growth and production of antimicrobial metabolite. The bacteria was incubated at 37°C and samples were taken 24 hourly from 0 to 240 hours.…”

Section: Molecular and Morphological Characterizationmentioning

confidence: 99%

Antimicrobial Activity of Bacillus Sp. Jg: Isolation, Identification and Process Optimization for the Production of Antimicrobial Metabolite Against Human Pathogens

Jain¹

2017

WJPPS

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Antibiotic resistance in bacteria has become a serious problem. Therefore, the search for new antibiotics is an important endeavour and is very much needed. In the present investigation, a number of bacterial strains were isolated from different soil samples and were tested for antimicrobial metabolite production. 85 bacterial isolates were isolated and the best activity was exhibited by the bacterial isolate P13. Physiological, biochemical and 16S rDNA gene sequence analysis strongly suggested that the isolate P13 belonged to Bacillus sp. Effect of medium, incubation period, pH and temperature variations for the maximum production of antimicrobial metabolite were optimized for maximum antimicrobial metabolite production. The maximum production of antimicrobial metabolite was observed in WYH under pH 7.0 and incubation temperature of 35 o C. Nutritional and culture conditions for the production of antimicrobial metabolite by this organism under shake-flask conditions were also optimized. Dextrose and peptone were found to be the best carbon and nitrogen sources for the production of antimicrobial metabolite by Bacillus sp. JG. Chloroform was the best extraction solvent for the isolation of the antimicrobial metabolite. The minimum inhibitory concentration of the metabolite against the test pathogens ranged between 0.9 to 2mg/ml. It may be suggested from the present study that further research is needed for World Journal of Pharmacy and Pharmaceutical Sciencesdetermining the chemical structure of metabolite which is responsible for bio-efficacy and to determine the cytotoxicity before it is used for commercialization purposes.

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Enhanced antibiotic activity of Xenorhabdus nematophila by medium optimization

Cited by 26 publications

References 18 publications

Improvement of antibiotic activity of Xenorhabdus bovienii by medium optimization using response surface methodology

Improvement of antibiotic activity of Xenorhabdus bovienii by medium optimization using response surface methodology

Molecular identification and genetic diversity among Photorhabdus and Xenorhabdus isolates

Antimicrobial Activity of Bacillus Sp. Jg: Isolation, Identification and Process Optimization for the Production of Antimicrobial Metabolite Against Human Pathogens

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