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

Abstract

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.

Could termites be hiding a goldmine of obscure yet promising yeasts for energy crisis solutions based on aromatic wastes? A critical state-of-the-art review

“…Termite gut symbionts secrete cellulases, hemicellulases, and lignin-modifying enzymes [ 121 ]. Figure 12 illustrates the lignocellulose degradation mechanisms in the digestive tracts of lower and higher termites [ 122 , 123 ]. Hydrolysis of cellulose was initiated in the foregut of lower termites initiate cellulose hydrolysis in the foregut via salivary gland secretion of β-glucosidases and endoglucanases [ 124 ].…”

“…The β-glucosidase and endoglucanase activities of Macrotermitinae can be found in both the salivary glands and the midgut of these termites. The β-glucosidase and endoglucanase activities of Odontotermes formosanus (Shiraki) are produced in the salivary glands [ 129 ], whereas Macrotermes barneyi secrete β-glucosidase and endoglucanase in the midgut [ 123 ]. As opposed to other subfamilies of higher termites, the activity of lignocellulose-degrading enzymes in Macrotermitinae is more complex, owing to the presence of basidiomycete fungi within the nest, which are distinguished by their lignocellulose degradation abilities [ 130 ].…”

Re-understanding evolution: the Information Continuum Model

“…While the examples above all concern information embedded in molecules transmitted via germ cells, symbionts may also serve as living carriers of inherited information. An example of this is seen in the microbial flora of termites, which demonstrate colony-to-offspring inheritance (among other modes of inheritance) and is vital for the symbionts' joint digestion of plant biomass 21,22 . Another example is the fetal colonization of maternal bacteria found in humans, that have lifelong effects on children's health 23,24 .…”

Tripartite Symbiotic Digestion of Lignocellulose in the Digestive System of a Fungus-Growing Termite

“…Fungus-growing termites, subfamily Macrotermitinae (Blattodea: Termitidae), are among the most successful phytophagous insects ( 11 , 12 ). They can consume 20 to 90% of dead plant materials in tropical and subtropical areas of the world ( 13 – 15 ).…”