ISSN:
1573-0972
Keywords:
Bentazon
;
herbicides
;
lignin peroxidase
;
manganese peroxidase
;
Phanerochaete chrysosporium
;
solid substrate fermentation
;
white rot fungus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract Enzyme production and degradation of the herbicide bentazon by Phanerochaete chrysosporium growing on straw (solid substrate fermentation, SSF) and the effect of nitrogen and the hydraulic retention time (HRT) were studied using a small bioreactor and batch cultures. The best degradation of bentazon was obtained in the low nitrogen treatments, indicating participation of the ligninolytic system of the fungus. The treatments that degraded bentazon also had manganese peroxidase (MnP) activity, which seemed to be necessary for degradation. Pure MnP (with Mn(II) and H2O2) did not oxidize bentazon. However, in the presence of MnP, Mn(II) and Tween 80, bentazon was slowly oxidized in a H2O2-independent reaction. Bentazon was a substrate of pure lignin peroxidase (LiP) and was oxidized significantly faster (22,000–29,000 times) as compared to the MnP-Tween 80 system. Although LiP was a better enzyme for bentazon oxidation in vitro, its role in the SSF systems remains unclear since it was detected only in treatments with high nitrogen and high HRT where no degradation of bentazon occurred. Inhibition of LiP activity may be due to phenols and extractives present in the straw.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008936617596
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