Biosurfactant production by Bacillus subtilis using corn steep liquor as culture medium

In this work, biosurfactant production by Bacillus subtilis #573 was evaluated using corn steep liquor (CSL) as culture medium. The best results were obtained in a culture medium consisting of 10% (v/v) of CSL, with a biosurfactant production of about 1.3 g/l. To the best of our knowledge, this is the first report describing biosurfactant production by B. subtilis using CSL as culture medium. Subsequently, the effect of different metals (iron, manganese, and magnesium) on biosurfactant production was evaluated using the medium CSL 10%. It was found that for all the metals tested, the biosurfactant production was increased (up to 4.1, 4.4, and 3.5 g/l for iron, manganese, and magnesium, respectively). When the culture medium was supplemented with the optimum concentration of the three metals simultaneously, the biosurfactant production was increased up to 4.8 g/l. Furthermore, the biosurfactant exhibited a good performance in oil recovery assays when compared with chemical surfactants, which suggests its possible application in microbial enhanced oil recovery or bioremediation.The authors acknowledge the financial support from the Strategic Project PEst-OE/EQB/LA0023/2013 and project ref. RECI/BBB-EBI/0179/2012 (project number FCOMP-01-0124-FEDER-027462) funded by Fundacao para aCiencia e a Tecnologia, and from AdI (Agencia de Inovacao, S.A.), through the project BIOCLEAN - "Development of biosurfactant- based products for surfaces cleaning and desinfection in the food industry" (QREN Ref. 30215)

Sorbic and benzoic acid in non-preservative-added food products in Turkey

PMID = 2478662

Impact of Food Disinfection on Beneficial Biothiol Contents in Strawberry

In this study, the impact of four food disinfectants including hydrogen peroxide, free chlorine, and gaseous- and aqueous-phase ozone with industrial doses on the concentration of biothiol compounds γ-glutamylcysteinylglycine (GSH) and cystein (CYS) in strawberry was investigated for 1, 5, 15, 30, and 60 or 120 min. Additionally, the amount of oxidized glutathione (GSSG) was analyzed for calculation of the GSH/GSSG ratio as an indicator of oxidative stress. After this treatment, thiol contents of strawberry samples were examined using high-performance liquid chromatography (HPLC) technique. According to the results of measurements, free chlorine treatment for only 60 min significantly decreased CYS content in strawberry (p \u3c 0.05). A significant decline in the GSH/GSSG ratio was also observed when H2O2 was applied for all time intervals except for 1 min (p \u3c 0.05). However, aqueous-phase ozone treatment did not significantly affect the thiol levels (p \u3c 0.05). In conclusion, this study may provide optimum disinfection methods for strawberry to minimize loss of beneficial biothiols