Multipartite symbioses in fungus-growing termites (Blattodea: Termitidae, Macrotermitinae) for the degradation of lignocellulose.

Fungus-growing termites are among the most successful herbivorous animals and improve crop productivity and soil fertility. A range of symbiotic organisms can be found inside their nests. However, interactions of termites with these symbionts are poorly understood. This review provides detailed information on the role of multipartite symbioses (between termitophiles, termites, fungi, and bacteria) in fungus-growing termites for lignocellulose degradation. The specific functions of each component in the symbiotic system are also discussed. Based on previous studies, we argue that the enzymatic contribution from the host, fungus, and bacteria greatly facilitates the decomposition of complex polysaccharide plant materials. The host-termitophile interaction protects the termite nest from natural enemies and maintains the stability of the microenvironment inside the colony.

Termitomyces heimii Associated with Fungus-Growing Termite Produces Volatile Organic Compounds (VOCs) and Lignocellulose-Degrading Enzymes.

Termitomyces fungi associated with fungus-growing termites are the edible mushrooms and can produce useful chemicals, enzymes, and volatile organic compounds (VOCs) that have both fuel and biological potentials. To this purpose, we examined the Termitomyces mycelial growth performance on various substrates, clarified lignocellulose-degrading enzyme activity, and also identified the VOCs produced by Termitomyces. Our results indicated that the optimal nutrition and condition requirements for mycelial growth are D-sorbitol, D-(+)-glucose, and D-(-)-fructose as carbon sources; peptone as well as yeast extract and ammonium tartrate as nitrogen sources; and Mn2+, Na+, and Mg2+ as metal ions with pH range from 7.0 to 8.0. Besides, the orthogonal matrix method results revealed that the ideal composition for mycelial growth is 20 g/L D-(-)-fructose, 5 g/L yeast extract, 0.5 g/L Mg2+, and pH = 7. We also screened various substrates composition for the activity of lignocellulose-degrading enzymes, i.e., lignin peroxidase, manganese peroxidase, ß-glucosidase, a-L-arabinofuranosidase, and laccase. Furthermore, we identified 37 VOCs using GC-MS, and the most striking aspect was the presence of a big series of alcohols and acids, collectively constituted about 49% of the total VOCs. Ergosta-5, 8, 22-trien-3-ol, (3.beta.,22E) was the most plenteous compound constituted 30.369%. This study hopes to establish a better understanding for researchers regarding Termitomyces heimii cultivation on a large scale for the production of lignocellulosic enzymes and some fungal medicine.

Investigation of Physicochemical Indices and Microbial Communities in Termite Fungus-Combs.

Termitomyces species are wild edible mushrooms that possess high nutritional value and a wide range of medicinal properties. However, the cultivation of these mushrooms is very difficult because of their symbiotic association with termites. In this study, we aimed to examine the differences in physicochemical indices and microbial communities between combs with Termitomyces basidiomes (CF) and combs without Termitomyces basidiomes (CNF). High-performance liquid chromatography (HPLC), inductively coupled plasma optical emission spectrometry (ICP-OES), gas chromatography equipped with a flame ionization detector (GC-FID), some commercial kits, high-throughput sequencing of the 16s RNA, and internal transcribed spacer (ITS) were used. Humidity, pH, and elements, i.e., Al, Ba, Fe, Mn, Ni, S, Ca, and Mg were higher while amino acids particularly alanine, tyrosine, and isoleucine were lower in CF as compared to CNF. The average contents of fatty acids were not significantly different between the two comb categories. The bacterial genera Alistipes, Burkholderia, Sediminibacterium, and Thermus were dominant in all combs. Brevibacterium, Brevundimonas, and Sediminibacterium were significantly more abundant in CF. Basidiomycota and Ascomycota were also identified in combs. Termitomyces clypeatus, Termitomyces sp. Group3, and Termitomyces sp. were the most dominant species in combs. However, any single Termitomyces species was abundantly present in an individual comb.