Briones-Roblero Carlos I, Rodríguez-Díaz Roberto, Santiago-Cruz José A, Zúñiga Gerardo, Rivera-Orduña Flor N
Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Laboratorio de Variación Biológica y Evolución, Prol. Carpio Esq. Plan de Ayala s/n, Casco de Santo Tomás, C. P. 11340, México D. F, Mexico.
Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Laboratorio de Ecología Microbiana, Prol. Carpio Esq. Plan de Ayala s/n, Casco de Santo Tomás, C. P. 11340, México D. F, Mexico.
Folia Microbiol (Praha). 2017 Jan;62(1):1-9. doi: 10.1007/s12223-016-0469-4. Epub 2016 Aug 20.
Bark beetles (Curculionidae: Scolytinae) feed on the xylem and phloem of their host, which are composed of structural carbohydrates and organic compounds that are not easily degraded by the insects. Some of these compounds might be hydrolyzed by digestive enzymes produced by microbes present in the gut of these insects. In this study, we evaluated the enzymatic capacity of bacteria (Acinetobacter lwoffii, Arthrobacter sp., Pseudomonas putida, Pseudomonas azotoformans, and Rahnella sp.) and yeasts (Candida piceae, Candida oregonensis, Cyberlindnera americana, Zygoascus sp., and Rhodotorula mucilaginosa) isolated from the Dendroctonus rhizophagus gut to hydrolyze cellulose, xylan, pectin, starch, lipids, and esters. All isolates, with the exception of C. piceae, showed lipolytic activity. Furthermore, P. putida, P. azotoformans, C. americana, C. piceae, and R. mucilaginosa presented amylolytic activity. Esterase activity was shown by A. lwoffii, P. azotoformans, and Rahnella sp. Cellulolytic and xylanolytic activities were present only in Arthrobacter sp. and P. azotoformans. The pectinolytic activity was not recorded in any isolate. This is the first study to provide evidence on the capacity of microbes associated with the D. rhizophagus gut to hydrolyze specific substrates, which might cover part of the nutritional requirements for the development, fitness, and survival of these insects.
树皮甲虫（象甲科：小蠹亚科）以其寄主的木质部和韧皮部为食，这些组织由结构性碳水化合物和不易被昆虫降解的有机化合物组成。其中一些化合物可能会被这些昆虫肠道中存在的微生物产生的消化酶水解。在本研究中，我们评估了从食根小蠹肠道分离出的细菌（鲁氏不动杆菌、节杆菌属、恶臭假单胞菌、产氮假单胞菌和拉恩菌属）和酵母（云杉假丝酵母、俄勒冈假丝酵母、美洲嗜杀酵母、合轴酵母属和粘红酵母）水解纤维素、木聚糖、果胶、淀粉、脂质和酯类的酶活性。除云杉假丝酵母外，所有分离株均表现出脂解活性。此外，恶臭假单胞菌、产氮假单胞菌﹑美洲嗜杀酵母、云杉假丝酵母和粘红酵母具有淀粉酶活性。鲁氏不动杆菌、产氮假单胞菌和拉恩菌属表现出酯酶活性。纤维素分解和木聚糖分解活性仅存在于节杆菌属和产氮假单胞菌中。在任何分离株中均未记录到果胶分解活性。这是第一项提供证据证明与食根小蠹肠道相关的微生物水解特定底物能力的研究，这些底物可能满足这些昆虫发育、健康和生存的部分营养需求。
