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淡紫拟青霉（Ｐａｅｃｉｌｏｍｙｃｅｓｌｉｌａｃｉｎｕｓ）是一种重要的植物线虫卵寄生真菌。采用ＤＥＡＥ－２２离子交换层析和ＳｅｐｈｃｒｙｌＳ－３００凝胶过滤层析分离纯化到一种淡紫拟青霉胞外几丁质酶，经７．５％聚丙烯酰胺凝胶电脉检测为单一条酶带，Ｒｆ值等于０．４３。淡紫拟青霉几丁质酶的最适温度为４５℃。热稳定性测定表明它在４０℃下放置１０ｍｉｎ可保持原有活力，６０℃下１０ｍｉｎ，完全失活。该酶的最适ｐＨ值为５。其ｐＨ值稳定性与温度和反应时间有关。２０℃、２０ｍｉｎ，在ｐＨ３～９范围内稳定；３７℃、１ｈ，则只在ｐＨ５～７范围内较稳定。金属离子如Ｍｇ２＋、Ｃａ２＋、Ｚｎ２＋、Ｌｉ＋和Ｆｅ２＋对酶有一定的激活作用，其中Ｍｇ２＋的激活作用最强。相反，Ｃｕ２＋对酶有强烈抑制作用。
Paecilomyces lilacinus is an important plant nematode egg parasitic fungus. A kind of extracellular chitinase from Paecilomyces lilacinus was isolated and purified by DEAE-22 ion exchange chromatography and Sephcryl S-300 gel filtration chromatography, which was detected by 7.5% polyacrylamide gel electrophoresis as a single Enzyme band, Rf equals 0.43. The optimal temperature for Paecilomyces lilacinus chitinase was 45 ℃. The thermostability test showed that it remained at 40 ℃ for 10min to maintain the original vitality, 60 ℃ for 10min, completely inactivated. The optimum pH of the enzyme is 5. Its pH stability and temperature and reaction time. 20 ℃, 20min, stable within the range of pH3 ~ 9; 37 ℃, 1h, only in the range of pH5 ~ 7 more stable. Metal ions such as Mg2 +, Ca2 +, Zn2 +, Li + and Fe2 + have some activation on the enzyme, of which Mg2 + has the strongest activation. In contrast, Cu2 + has a strong inhibitory effect on the enzyme.