Mendes Thais D, Rodrigues André, Dayo-Owoyemi Ifeloju, Marson Fernando A L, Pagnocca Fernando C
EMBRAPA-Agroenergy/Parque Estação Biológica, Brasília, DF 70770-901, Brazil.
Department of Biochemistry and Microbiology, UNESP-São Paulo State University, Rio Claro, SP 13506-900, Brazil.
Insects. 2012 Feb 17;3(1):228-45. doi: 10.3390/insects3010228.
The possible roles played by yeasts in attine ant nests are mostly unknown. Here we present our investigations on the plant polysaccharide degradation profile of 82 yeasts isolated from fungus gardens of Atta and Acromyrmex species to demonstrate that yeasts found in ant nests may play the role of making nutrients readily available throughout the garden and detoxification of compounds that may be deleterious to the ants and their fungal cultivar. Among the yeasts screened, 65% exhibited cellulolytic enzymes, 44% exhibited pectinolytic activity while 27% and 17% possess enzyme systems for the degradation of protease and amylase, respectively. Galacturonic acid, which had been reported in previous work to be poorly assimilated by the ant fungus and also to have a negative effect on ants' survival, was assimilated by 64% and 79% of yeasts isolated from nests of A. texana and Acromyrmex respectively. Our results suggest that yeasts found in ant nests may participate in generation of nutrients and removal of potentially toxic compounds, thereby contributing to the stability of the complex microbiota found in the leaf-cutting ant nests.
酵母在切叶蚁蚁巢中可能发挥的作用大多未知。在此，我们展示了对从阿塔属（Atta）和顶切叶蚁属（Acromyrmex）真菌园分离出的82种酵母进行的植物多糖降解情况的研究，以证明在蚁巢中发现的酵母可能起到使整个真菌园都能轻易获取养分以及对可能对蚂蚁及其真菌培养物有害的化合物进行解毒的作用。在所筛选的酵母中，65%表现出纤维素分解酶活性，44%表现出果胶分解活性，而分别有27%和17%的酵母拥有降解蛋白酶和淀粉酶的酶系统。在之前的研究中曾报道，半乳糖醛酸不易被蚁巢真菌同化，且对蚂蚁的生存有负面影响，但从德克萨斯切叶蚁（A. texana）和顶切叶蚁巢中分离出的酵母分别有64%和79%能够同化半乳糖醛酸。我们的研究结果表明，在蚁巢中发现的酵母可能参与养分的生成和潜在有毒化合物的清除，从而有助于维持切叶蚁蚁巢中复杂微生物群落的稳定性。
