Production of lipopeptide iturin a using novel strain Bacillus iso 1 in a packed bed bioreactor

Abstract

In the present study, the influence of volumetric airflow rate and rice husk as a bulking agent were evaluated in packed bed bioreactors to the production of lipopeptide iturin A. The iturin A is a powerful antifungal composed by seven α-amino acid rings linked to a β-amino fatty acid chain with an alkyl chain that can be linear or branched. The solid state fermentations (SSF) were carried out using a new strain Bacillus iso 1 as ferment and wheat bran and soybean meal as substrates at 30 °C for 96 h. It was found that the concentration of rice husk and volumetric airflow rate in the range of 20–40% (w/w) and 0.4–0.8 L/min are important operational parameters for the production of iturin A in packed bed bioreactors. The highest iturin A production (6.88 g/kg of dry substrate) was achieved when SSF was carried out with a 22.9% (w/w) of rice husk and a volumetric airflow rate of 0.46 L/min. These promising results show the potential of the new strain Bacillus iso 1 to produce high concentrations of lipopeptide iturin A using cheap agro-industrial substrates in packed bed bioreactors with forced aeration, in order to develop an industrial production processes.