Selection and characterization of mutants of Phanerochaete chrysosporium exhibiting ligninolytic activity under nutrient-rich conditions.
Selection and characterization of mutants of Phanerochaete chrysosporium exhibiting ligninolytic activity under nutrient-rich conditions.
复制标题
在营养丰富的条件下表现出木质素分解活性的黄孢原毛平革菌突变体的选择和表征。
DOI：
10.1128/aem.56.8.2540-2544.1990
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发表时间：
1990
影响因子：
4.4
通讯作者：
Myer,SB
中科院分区：
文献类型：
--
作者：
Tien,M;Myer,SB
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Synthesis of the ligninolytic system of the wood-degrading fungus Phanerochaete chrysosporium is induced during secondary metabolism, brought about by nitrogen, carbon, or sulfur starvation. We describe here a strategy for selection of mutants which are ligninolytic (lignin----CO2) and overproduce lignin-degrading enzymes (ligninases) under nutrient-rich conditions (during primary metabolism). The strategy is based on using an adduct of lysine and a lignin model compound. Ligninase-dependent oxidation of this adduct releases free lysine, which complements the lysine requirements of a lysine auxotroph. Accordingly, a lysine auxotroph was mutagenized by UV irradiation and survivors were plated onto medium containing the adduct and high ammonia nitrogen. Four mutants which overproduce the ligninase isozymes were isolated by this procedure. Further characterization of one of the mutants, PSBL-1, indicated that the predominant isozymes produced are H1 (pI = 4.7) and H2 (pI = 4.4). The ligninase activity of PSBL-1, measured by veratryl alcohol oxidation, peaks on day 5 at over 1,000 U.liter-1. The mutant PSBL-1 was also able to degrade [14C]lignin to 14CO2, indicating that the complete ligninolytic system is deregulated.