Statistical Design, a Powerful Tool for Optimizing Biosurfactant Production: A Review <s> Physicochemical Factors Affecting Bs Production: The Effect of pH, Temperature, and Shaking <s> Abstract In this study, we have investigated the potential of a native bacterial strain isolated from an Iranian oil field for the production of biosurfactant. The bacterium was identified to be Bacillus mycoides by biochemical tests and 16S ribotyping. The biosurfactant, which was produced by this bacterium, was able to reduce the surface tension of media to 34 mN/m. Compositional analysis of the produced biosurfactant has been carried out by thin layer chromatography (TLC) and FT-IR. The biosurfactant produced by the isolate was characterized as lipopeptide derivative. Biosurfactant production was optimized by the combination of central composite design (CCD) and response surface methodology (RSM). The factor selected for optimization of growth conditions were pH, temperature, glucose and salinity concentrations. The empirical model developed through RSM in terms of effective operational factors mentioned above was found to be adequate to describe the biosurfactant production. Through the analysis, glucose and temperature were found to be the most significant factors, whereas pH and salinity had less effect within the ranges investigated. A maximum reduction in surface tension was obtained under the optimal conditions of 16.55 g/l glucose concentration, 39.03 °C, 55.05 g/l total salt concentration and medium pH 7.37. <s> BIB001 </s> Statistical Design, a Powerful Tool for Optimizing Biosurfactant Production: A Review <s> Physicochemical Factors Affecting Bs Production: The Effect of pH, Temperature, and Shaking <s> Aims: To screen and identify biosurfactant producers from petroleum-contaminated soil; to use response surface methodology (RSM) for medium optimization to enhance biosurfactant production; and to study the properties of the newly obtained biosurfactant towards pH, temperature and salinity. ::: Methods and Results: We successfully isolated three biosurfactant producers from petroleum-contaminated soil and identified them through 16S rRNA sequence analysis, which exhibit the highest similarities to Acinetobacter beijerinckii (100%), Kocuria marina (99%) and Kineococcus marinus (99%), respectively. A quadratic response model was constructed through RSM designs, leading to a 57AE5% increase of the growth-associated biosurfactant production ::: by Acinetobacter sp. YC-X 2 with an optimized medium: beef extract ::: 3AE12 g l)1 ; peptone 20AE87 g l)1 ; NaCl 1AE04 g l)1 ; and n-hexadecane 1AE86 g l)1. Biosurfactant produced by Acinetobacter sp. YC-X 2 retained its properties during exposure to a wide range of pH values (5–11), high temperatures (up to 121C) and high salinities [up to 18% (w⁄ v) Na+ and Ca2+], which was more sensitive to Ca2+ than Na+ . ::: Conclusions: Two novel biosurfactant producers were isolated from petroleumcontaminated soil. Biosurfactant from Acinetobacter sp. YC-X 2 has good properties to a wide range of pH, high temperature and high salinity, and its production was optimized successfully through RSM. <s> BIB002 </s> Statistical Design, a Powerful Tool for Optimizing Biosurfactant Production: A Review <s> Physicochemical Factors Affecting Bs Production: The Effect of pH, Temperature, and Shaking <s> A potent biosurfactant-producing bacterial strain isolated from spoiled apples was identified by 16S rRNA as Pseudomonas aeruginosa MA01. Compositional analysis revealed that the extracted biosurfactant was composed of high percentages of lipid (66%, w/w) and carbohydrate (32%, w/w). The surface tension of pure water decreased gradually with increasing biosurfactant concentration to 32.5 mN m(-1) with critical micelle concentration (CMC) value of 10.1 mg L(-1). The Fourier transform infrared spectrum of extracted biosurfactant confirmed the glycolipid nature of this natural product. Response surface methodology (RSM) was employed to optimize the biosynthesis medium for the production of MA01 biosurfactant. Nineteen carbon sources and 11 nitrogen sources were examined, with soybean oil and sodium nitrate being the most effective carbon and nitrogen sources on biosurfactant production, respectively. Among the organic nitrogen sources examined, yeast extract was necessary as a complementary nitrogen source for high production yield. Biosurfactant production at the optimum value of fermentation processing factor (15.68 g/L) was 29.5% higher than the biosurfactant concentration obtained before the RSM optimization (12.1 g/L). A central composite design algorithm was used to optimize the levels of key medium components, and it was concluded that two stages of optimization using RSM could increase biosurfactant production by 1.46 times, as compared to the values obtained before optimization. <s> BIB003 </s> Statistical Design, a Powerful Tool for Optimizing Biosurfactant Production: A Review <s> Physicochemical Factors Affecting Bs Production: The Effect of pH, Temperature, and Shaking <s> Abstract The maximisation of the production of metabolites of industrial interest from fermentative processes, such as biosurfactants, requires standardisation of the medium and the cultivation conditions. In this sense, experiments were conducted to maximise the production of the biosurfactant from Candida lipolytica UCP0988 cultivated on 5% animal fat and 2.5% corn steep liquor using a 23 full factorial design. The effects and interactions of the agitation speed (200, 300 and 400 rpm), the variables aeration (0, 1 and 2 vvm) and time of cultivation (48, 96 and 144 h) on the surface tension, yield and biomass were evaluated. The results showed that the variable time of cultivation had positive influence on the production of biosurfactant, while the increase of the variables aeration and agitation showed a negative effect. These results indicate that the biosurfactant has a strong potential to be applied as a clean-up of oil spills at sea and on shorelines. <s> BIB004
Bs production is dependent on pH and temperature although Bs production varies with microorganisms. However, optimum Bs production is generally near neutral pH, although some reports suggest a slight increase in pH from 7-8.5 BIB002 BIB001 . Normally, the best temperatures for Bs production reported are in the range of 35-40 • C BIB001 . Shaking has also been shown to affect Bs production. The greater oxygenation at higher shaking speed is related to higher metabolism rates BIB003 BIB004 .