Evaluation of different Bacillus strains in respect of their ability to produce Surfactin in a model fermentation process with integrated foam fractionation

Abstract

Biosurfactants increasingly gain attention due to the manifold of possible applications and production on the basis of renewable resources. Owing to its various characteristics, Surfactin is one of the most studied biosurfactants. Since its discovery, several Surfactin producers have been identified, but their capacity to produce Surfactin has not been evaluated in a comparison. Six different Bacillus strains were analyzed regarding their ability to produce Surfactin in model fermentations with integrated foam fractionation, for in situ product enrichment and removal. Three of the investigated strains are commonly used in Surfactin production (ATCC 21332, DSM 3256, DSM 3258), whereas two Bacillus strains are described for the first time (DSM 1090, LM43a50°C) as Surfactin producers. Additionally, the Bacillus subtilis type strain DSM 10(T) was included in the evaluation. Interestingly, all strains, except DSM 3256, featured high values for Surfactin recovered from foam in comparison to other studies, ranging between 0.4 and 1.05 g. The fermentation process was characterized by calculating procedural parameters like substrate yield Y X/S, product yield Y P/X, specific growth rate μ, specific productivity q Surfactin, volumetric productivity q Surfactin, Surfactin and bacterial enrichment as well as Surfactin recovery. The strains differ most in specific and volumetric productivity; nevertheless, it is evident that it is not possible to name a Bacillus strain that is the most appropriate for the production of Surfactin under these conditions. In contrast, it becomes apparent that the choice of a specific strain should depend on the applied fermentation conditions.

Microbial lipopeptide production and purification bioprocesses, current progress and future challenges

“…Integrated in continuous process, the recovery reached around 70%. This process was also evaluated recently by Willenbacher et al with different surfactin producing strains of B. subtilis and similar recovery results were obtained.…”

Two‐phase olive mill waste (alpeorujo) as carbon source for biosurfactant production

“…Bacillus subtilis DSM 3256 is a known producer of surfactin . To confirm the presence of surfactin in the partially purified biosurfactant, its infrared absorption spectrum was compared with that of standard surfactin.…”

“…The purpose of this work is to evaluate the potential of TPOMW as the main carbon source for the production of biosurfactants with Bacillus subtilis DSM 3256, a well‐known producer of surfactin . The time course of fermentation was followed by measuring pH and surface tension of the cell‐free supernatant, as well as biosurfactant and biomass concentration throughout the process.…”

“…The purpose of this work is to evaluate the potential of TPOMW as the main carbon source for the production of biosurfactants with Bacillus subtilis DSM 3256, a well-known producer of surfactin. 16 The time course of fermentation was followed by measuring pH and surface tension of the cell-free supernatant, as well as biosurfactant and biomass concentration throughout the process. The chemical structure of the biosurfactant, and its interfacial properties, such as surface and interfacial tension, critical micelle concentration, and the ability to produce stable emulsions, were also evaluated.…”

Direct quantification of lipopeptide biosurfactants in biological samples via HPLC and UPLC-MS requires sample modification with an organic solvent

“…This limitation also concerns the quantification of LPs. In several research papers, HPLC analysis of lipopeptides varied from 20 to up to 100 min per sample (Lin et al 2007; Isa et al 2007; De Bruijn et al 2008; Yokota et al 2012; Willenbacher et al 2014; Zhu et al 2014). In contrast, up to 20 samples containing SU, iturin A, and fengycin can be quantified simultaneously with HPTLC in 80 min (Geissler et al 2016).…”