Insect Science (2010) 17, 265–276, DOI 10.1111/j.1744-7917.2010.01327.x
ORIGINAL ARTICLE Comparison of gut-associated and nest-associated microbial communities of a fungus-growing termite (Odontotermes yunnanensis)
Yan-Hua Long1,2, Lei Xie2, Ning Liu2,XingYan2, Ming-Hui Li2, Mei-Zhen Fan1 and Qian Wang2 1Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, 2Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
Abstract The digestion of cellulose by fungus-growing termites involves a complex of different organisms, such as the termites themselves, fungi and bacteria. To further investi- gate the symbiotic relationships of fungus-growing termites, the microbial communities of the termite gut and fungus combs of Odontotermes yunnanensis were examined. The ma- jor fungus species was identified as Termitomyces sp. To compare the micro-organism diversity between the digestive tract of termites and fungus combs, four polymerase chain reaction clone libraries were created (two fungus-targeted internal transcribed spacer [ITS] – ribosomal DNA [rDNA] libraries and two bacteria-targeted 16S rDNA libraries), and one library of each type was produced for the host termite gut and the symbiotic fungus comb. Results of the fungal clone libraries revealed that only Termitomyces sp. was detected on the fungus comb; no non-Termitomyces fungi were detected. Meanwhile, the same fun- gus was also found in the termite gut. The bacterial clone libraries showed higher numbers and greater diversity of bacteria in the termite gut than in the fungus comb. Both bacte- rial clone libraries from the insect gut included Firmicutes, Bacteroidetes, Proteobacteria, Spirochaetes, Nitrospira, Deferribacteres, and Fibrobacteres, whereas the bacterial clone libraries from the fungal comb only contained Firmicutes, Bacteroidetes, Proteobacteria, and Acidobacteris. Key words fungus comb, gut, ITS, phylotype, termite, Termitomyces
Introduction ally classified at the taxonomic rank of the order Isoptera. This group contains five families of lower termites and Termites are the major contributors to the biodegrada- one family of higher termites (Noirot, 1992). The special tion of lignocellulose and hemicellulose in tropical areas subfamily of higher termites, Macrotermitinae, which can (Lee & Wood, 1971). Therefore, these insects are im- digest plant litter with high efficiency, is also referred to portant not only for their roles in carbon turnover in the as fungus-growing termites. These termites have gained environment, but also as potential sources of biochemi- the widespread interest of researchers due to their symbi- cal catalysts for converting wood into biofuels (Warnecke otic relationship with basidiomycete fungi of the genus et al., 2007). Termites are a group of social insects usu- Termitomyces (Agaricales: Tricholomataceae) (Abe & Matsumoto, 1979; Wood & Sands, 1978). Fungus-growing termites are distributed throughout Correspondence: Qian Wang, Institute of Plant Physiology tropical and subtropical areas in Africa and Asia. They and Ecology, Shanghai Institutes for Biological Sciences, Chi- have evolved into approximately 330 extant species, nese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032 belonging to approximately 12 genera (Kambhampati China. Tel: +86 21 54924046; fax: +86 21 54920078; email: & Eggleton, 2000). Inside the nests of these termites, [email protected] Termitomyces is cultured by termites on a special