Effects of critical medium components on the production of antifungal lipopeptides from Bacillus amyloliquefaciens Q-426 exhibiting excellent biosurfactant properties

Abstract

In this study, influence of three critical parameters nitrogen sources, initial pH and metal ions was discussed in the production of antifungal lipopeptides from Bacillus amyloliquefaciens Q-426. The results revealed that lipopeptide biosynthesis might have relations with the population density of strain Q-426 and some special amino acids. Also, the alkali-resistant strain Q-426 could grow well in the presence of Fe 2? ions below 0.8 M l -1 and still maintain the competitive advantage below 0.2 M l -1 . Moreover, lipopeptides exhibited significant inhibitory activities against Curvularia lunata (Walk) Boed even at the extreme conditions of temperature, pH and salinity. Finally, biosurfactant properties of lipopeptides mixture were evaluated by use with totally six different methods including bacterial adhesion to hydrocarbons assay, lipase activity, hemolytic activity, emulsification activity, oil displacement test and surface tension measurement. The research suggested that B. amyloliquefaciens Q-426 may have great potential in agricultural and environmental fields.

Inhibition of biofilm in Bacillus amyloliquefaciens Q-426 by diketopiperazines

“…amyloliquefaciens Q-426 had been isolated from compost samples in Dalian of China based on its antifungal activity. In previous study, B. amyloliquefaciens Q-426 was found to be a potential biocontrol agent against fungi and bacteria, but the biofilm formation played a negative role on it (Zhao et al 2013;Zhao et al 2014). In this study, the DKPs extracted from B. amyloliquefaciens Q-426, which was suspected as signal molecule of several bacterial (Degrassi et al 2002;Holden et al 1999;Wang et al 2010b), can inhibit the biofilm formation of the strain by inhibiting the extracellular polymeric matrix formation.…”

Secondary metabolites from Bacillus amyloliquefaciens isolated from soil can kill Burkholderia pseudomallei

“…Other compounds those were still active after proteolytic enzyme digestion could be the non-peptides group such as lipopeptides or polyketides. These antimicrobial substances were reported to resist a wide range of temperatures up to 100 °C (Pathak and Keharia 2014) and were also resistant to proteolytic enzyme digestion (Zhao et al 2013). …”

Non-edible Oil Cakes as a Novel Substrate for DPA Production and Augmenting Biocontrol Activity of Paecilomyces variotii

“…The quality as well as quantity of propagules is affected by medium composition and culture conditions (Gupta et al, 2016). Carbon-Nitrogen ratio as well as type of sugar in media plays an important role in determining the pathogenicity of the fungus (Vidal et al, 1998; Gao et al, 2007; Zhao et al, 2013; Nisha and Kalaiselvi, 2016). Therefore, nitrogen and carbon sources were screened for the production of bioactive molecule because they may influence the activity of phytopathogens, and enhances antibiotics production in biocontrol strains and contribute to the variability of biocontrol in different soils and also on host crops (Milner et al, 1995; Thomashow and Weller, 1996; Cliquet and Jackson, 2005; Moorthi et al, 2015).…”

“…Plackett and Burman's design (PBD), when applied to evaluate medium components, will screen the insignificant factors out of a large number of possible factors at fairly early stages of the experiment. Box Behnken Design (BBD) is useful in determining the effect of key factors, by minimum number of experiments for further optimization (Singh and Chhatpar, 2010; Zhao et al, 2013). No published reports to the best of our knowledge are available for increased production of the bioactive DPA from P. variotii using response surface methodology (RSM).…”