Kopecný J, Hodrová B, Stewart C S
Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Prague, Czech Republic.
Lett Appl Microbiol. 1996 Sep;23(3):195-8. doi: 10.1111/j.1472-765x.1996.tb00063.x.
Chitinolytic bacteria were detected in faeces and digesta of wild and domesticated herbivores. The presence of chitinolytic bacteria in two cows was verified following enrichment culture of rumen fluid on colloidal chitin. In three other cows, direct counts on chitin agar showed that the numbers of these bacteria in the rumen fluid ranged from 5 x 10(4) to 2 x 10(8) ml-1. Most of these bacteria were Clostridium-like spore producers. The most typical strain, Clostridium sp. ChK5, was characterized further. This bacterium degraded colloidal chitin and produced mainly acetate, butyrate and lactate. Endochitinase and chitobiase were produced when chitin was the growth substrate. Endochitinase was also detected in cultures grown on N-acetylglucosamine and glucose. Optimal conditions for endochitinase activity were 37 degrees C and pH 4.5-6.1. The Michaelis constant (Km) for this enzyme was 19.3 mg ml-1. Strain ChK5 shows strong phenotypic similarity to Clostridium tertium.
在野生和家养食草动物的粪便及消化物中检测到了几丁质分解菌。在用胶体几丁质对瘤胃液进行富集培养后，证实了两头奶牛体内存在几丁质分解菌。在另外三头奶牛中，通过在几丁质琼脂上直接计数发现，瘤胃液中这些细菌的数量在5×10⁴至2×10⁸ ml⁻¹之间。这些细菌大多是类似梭菌的产芽孢菌。对最典型的菌株梭菌ChK5进行了进一步鉴定。该细菌可降解胶体几丁质，主要产生乙酸、丁酸和乳酸。以几丁质作为生长底物时可产生内切几丁质酶和壳二糖酶。在以N - 乙酰葡糖胺和葡萄糖为培养基生长的培养物中也检测到了内切几丁质酶。内切几丁质酶活性的最佳条件是37℃和pH 4.5 - 6.1。该酶的米氏常数（Km）为19.3 mg ml⁻¹。ChK5菌株与第三梭菌表现出很强的表型相似性。
