摘要
测定３种常见天牛：桑粒肩天牛（ＡｐｒｉｏｎａｇｅｒｍａｒｉＨｏｐｅ）、星天牛（ＡｎｏｐｌｏｐｈｏｒａｃｈｉｎｅｎｓｉｓＦｏｒｓｔｅｒ）和桔褐天牛（ＮｅｄｅｚｈｄｉｅｌｌａｃａｎｔｏｒｉＨｏｐｅ）消化道纤维素酶活性，发现几种天牛幼虫均有完整的纤维素酶体系，即Ｃ１酶、Ｃｘ酶和β－葡萄糖苷酶，能真正消化利用食物中的纤维素成分；以微晶纤维素（ＭＣ）和羧甲基纤维素钠（ＣＭＣ－Ｎａ）为碳源的选择性培养基培养几种天牛肠液，未发现纤维分解真菌及能分解ＭＣ的细菌；肠道解剖及肠组织切片未发现特殊的共生菌囊及含菌细胞；比较天牛的纤维素酶与常见真菌纤维素酶的性质相差甚远。因而认为所研究的几种天牛其纤维素酶均为其自身分泌的内源性酶而不是来源于其它生物。
Cellulase extract preparation from intestinal tracts of the Apriona germari Hope (Lamiinae, feeding in phloem, sapwood and duramen of mulberry trees), Anoplophora chinensis Forster (Lamiinae, feeding in the sapwood and duramen of various host plants) and Nedezhdiella cantori (Hope) (Cerambyciinae, living in the heartwood of citrus trees) were tested to determine the hydrolytic abilities of digestive enzymes on various subtracts: microcrystalline cellulose (MC), sodium carboxymethyl cellulose (CMCNa) and salicin. It revealed that all of the three species could hydrolyze all the subtracts mentioned. The results indicated that the three species of cerambycids all did have cellulolytic enzyme complex: exo-β-1, 4-glucanase (C1-ase ), endo-β-1, 4 glucanase (Cx-ase ) and β-1,4-glucosidase in the gut, and possess a real cellulolytic capacity. Moreover, the C1-ase activity of the heartwood feeding species N. cantori would be higher than that of phloem and sapwood feeding species A. germari and A. chinensis. All the Borers examined are living in healthy trees, and they rarely encounter or consume fungus-infected wood; from the cultures of intestinal fluid on MC or CMC-Na selecting medium, no cellulolytic fungi was found on MC medium and only few bacteria on CMC-Na medium. In the tissue and microsection of dissected intestinal tracts there were not any special myctocytes or structure for harboring extracellular microorganisms.Comparing with the cellulases' characters between the common cellulolytic fungi and the cerambycid Borers, difference was very evident. Based on these facts, it was suggested that at least some of cerambycids would be able to secret cellulases and the cellulase complex should be endogenous rather than exogenous.
出处
《林业科学》
CAS
CSCD
北大核心
1996年第5期441-446,共6页
Scientia Silvae Sinicae
基金
国家教委博士点基金
关键词
纤维素酶
天牛
Cellulase, Cerambycids, Cellulase resource
