TY - JOUR
T1 - Production of human lysozyme in biofilm reactor and optimization of growth parameters of Kluyveromyces lactis K7
AU - Ercan, Duygu
AU - Demirci, Ali
N1 - Funding Information:
Acknowledgments This work was supported in part by the Turkish Ministry of Education by providing scholarship to Duygu Ercan, the Pennsylvania Experiment Station, and Agricultural Sciences Graduate Student Competitive Grants Program. We also thank Dr. Anthony L. Pometto III for helping manufacturing plastic composite supports. Moreover, we thank Hilmar Ingredients Inc. (Hilmar, CA, USA) for providing lactose.
PY - 2013/7
Y1 - 2013/7
N2 - Lysozyme (1,4-β-N-acetylmuramidase) is a lytic enzyme, which degrades the bacterial cell wall. Lysozyme has been of interest in medicine, cosmetics, and food industries because of its anti-bactericidal effect. Kluyveromyces lactis K7 is a genetically modified organism that expresses human lysozyme. There is a need to improve the human lysozyme production by K. lactis K7 to make the human lysozyme more affordable. Biofilm reactor provides high biomass by including a solid support, which microorganisms grow around and within. Therefore, the aim of this study was to produce the human lysozyme in biofilm reactor and optimize the growth conditions of K. lactis K7 for the human lysozyme production in biofilm reactor with plastic composite support (PCS). The PCS, which includes polypropylene, soybean hull, soybean flour, bovine albumin, and salts, was selected based on biofilm formation on PCS (CFU/g), human lysozyme production (U/ml), and absorption of lysozyme inside the support. To find the optimum combination of growth parameters, a three-factor Box-Behnken design of response surface method was used. The results suggested that the optimum conditions for biomass and lysozyme productions were different (27 C, pH 6, 1.33 vvm for biomass production; 25 C, pH 4, no aeration for lysozyme production). Then, different pH and aeration shift strategies were tested to increase the biomass at the first step and then secrete the lysozyme after the shift. As a result, the lysozyme production amount (141 U/ml) at 25 C without pH and aeration control was significantly higher than the lysozyme amount at evaluated pH and aeration shift conditions (p < 0.05).
AB - Lysozyme (1,4-β-N-acetylmuramidase) is a lytic enzyme, which degrades the bacterial cell wall. Lysozyme has been of interest in medicine, cosmetics, and food industries because of its anti-bactericidal effect. Kluyveromyces lactis K7 is a genetically modified organism that expresses human lysozyme. There is a need to improve the human lysozyme production by K. lactis K7 to make the human lysozyme more affordable. Biofilm reactor provides high biomass by including a solid support, which microorganisms grow around and within. Therefore, the aim of this study was to produce the human lysozyme in biofilm reactor and optimize the growth conditions of K. lactis K7 for the human lysozyme production in biofilm reactor with plastic composite support (PCS). The PCS, which includes polypropylene, soybean hull, soybean flour, bovine albumin, and salts, was selected based on biofilm formation on PCS (CFU/g), human lysozyme production (U/ml), and absorption of lysozyme inside the support. To find the optimum combination of growth parameters, a three-factor Box-Behnken design of response surface method was used. The results suggested that the optimum conditions for biomass and lysozyme productions were different (27 C, pH 6, 1.33 vvm for biomass production; 25 C, pH 4, no aeration for lysozyme production). Then, different pH and aeration shift strategies were tested to increase the biomass at the first step and then secrete the lysozyme after the shift. As a result, the lysozyme production amount (141 U/ml) at 25 C without pH and aeration control was significantly higher than the lysozyme amount at evaluated pH and aeration shift conditions (p < 0.05).
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U2 - 10.1007/s00253-013-4944-4
DO - 10.1007/s00253-013-4944-4
M3 - Article
C2 - 23657582
AN - SCOPUS:84879841797
SN - 0175-7598
VL - 97
SP - 6211
EP - 6221
JO - Applied Microbiology and Biotechnology
JF - Applied Microbiology and Biotechnology
IS - 14
ER -