title: Mathematic modeling for optimum conditions on aflatoxin B₁degradation by the aerobic bacterium Rhodococcus erythropolis.
abstract: Response surface methodology was employed to optimize the degradation conditions of AFB₁ by Rhodococcus erythropolis in liquid culture. The most important factors that influence the degradation, as identified by a two-level Plackett-Burman design with six variables, were temperature, pH, liquid volume, inoculum size, agitation speed and incubation time. Central composite design (CCD) and response surface analysis were used to further investigate the interactions between these variables and to optimize the degradation efficiency of R. erythropolis based on a second-order model. The results demonstrated that the optimal parameters were: temperature, 23.2 °C; pH, 7.17; liquid volume, 24.6 mL in 100-mL flask; inoculum size, 10%; agitation speed, 180 rpm; and incubation time, 81.9 h. Under these conditions, the degradation efficiency of R. erythropolis could reach 95.8% in liquid culture, which was increased by about three times as compared to non-optimized conditions. The result by mathematic modeling has great potential for aflatoxin removal in industrial fermentation such as in food processing and ethanol production.
authors.affiliation: School of Food Science and Engineering, Ocean University of China, Qingdao, Shandong 266003, China. kongqing@ouc.edu.cn
authors.forename: Qing
authors.initials: Q
authors.lastname: Kong
authors.forename: Cuiping
authors.initials: C
authors.lastname: Zhai
authors.forename: Bin
authors.initials: B
authors.lastname: Guan
authors.forename: Chunjuan
authors.initials: C
authors.lastname: Li
authors.forename: Shihua
authors.initials: S
authors.lastname: Shan
authors.forename: Jiujiang
authors.initials: J
authors.lastname: Yu
mesh_terms: D016604:Aflatoxin B1 / Q000737:chemistry*; D000704:Analysis of Variance; D010367:Arachis / Q000382:microbiology; D001230:Aspergillus / Q000254:growth & development; D001673:Biodegradation, Environmental; D005506:Food Contamination / Q000517:prevention & control* / Q000706:statistics & numerical data; D005516:Food Microbiology / Q000592:standards* / Q000706:statistics & numerical data; D006863:Hydrogen-Ion Concentration; D050296:Microbial Viability; D015233:Models, Statistical; D008962:Models, Theoretical; D012044:Regression Analysis; D012240:Rhodococcus / Q000201:enzymology / Q000254:growth & development*; D013696:Temperature
chemical_list: D016604:Aflatoxin B1