Izvorni znanstveni članak
Enhanced Production of Surfactin by Bacillus subtilis E8 Mutant Obtained by Ion Beam Implantation
Guohong Gong
; Key Laboratory of Ion Beam Bioengineering, Chinese Academy of Sciences, Hefei P.O. Box 1126, CN-230031 Anhui, PR China
Zhiming Zheng
; Key Laboratory of Ion Beam Bioengineering, Chinese Academy of Sciences, Hefei P.O. Box 1126, CN-230031 Anhui, PR China
Hua Chen
; Key Laboratory of Ion Beam Bioengineering, Chinese Academy of Sciences, Hefei P.O. Box 1126, CN-230031 Anhui, PR China
Chengling Yuan
; Key Laboratory of Ion Beam Bioengineering, Chinese Academy of Sciences, Hefei P.O. Box 1126, CN-230031 Anhui, PR China
Peng Wang
; Key Laboratory of Ion Beam Bioengineering, Chinese Academy of Sciences, Hefei P.O. Box 1126, CN-230031 Anhui, PR China
Liming Yao
; Key Laboratory of Ion Beam Bioengineering, Chinese Academy of Sciences, Hefei P.O. Box 1126, CN-230031 Anhui, PR China
Zengliang Yu
; Key Laboratory of Ion Beam Bioengineering, Chinese Academy of Sciences, Hefei P.O. Box 1126, CN-230031 Anhui, PR China
Sažetak
The application of surfactin is hampered by its high production cost. In this study, a high-producing surfactin mutant obtained by ion beam implantation, Bacillus subtilis E8, has been used to produce surfactin. The production in a modified bioreactor and the properties of the surfactin produced by the mutant strain have been investigated. The results indicate that the modified bioreactor with a cell/foam recycler showed an advantage as compared to a simple reactor. The concentration of crude surfactin (including recovery from two parts of foam and broth fractionation) increased significantly from 0.75 to 10.26 g/L. Time course profiles showed that surfactin produced by B. subtilis E8 was growth-associated during the exponential phase of biomass, and the growth-associated product formation constant (α) was 894 mg per g of dry cell (R^2=0.918). The concentration of crude surfactin and biomass reached a maximum (12.20 and 6.50 g/L) after cultivation for about 32 h. The crude and extracted surfactin (critical micelle concentrations were 15 and 13 μM, respectively) exhibited excellent emulsification property, pH stability, thermal stability and resistance to salts, which widens its potential application.
Ključne riječi
Bacillus subtilis; surfactin; ion beam implantation; biosurfactant; modified bioreactor
Hrčak ID:
33048
URI
Datum izdavanja:
26.3.2009.
Posjeta: 3.952 *