Although the reported potential of gut R788 chemical structure Actinobacteria to produce enzymes to possibly aid in food processing by their hosts (termites and scarabaeids) or to synthesize nutrients (hemipterans), the well-known potential of Actinobacteria to produce bioactive metabolites has led some to argue that these bacteria may also have a more general role in host protection against the invasion of pathogenic bacteria [22]. This

hypothesis has gained support by the growing body of information on the association of actinobacteria with insects, in which actinobacteria are ectopically associated with the integument of Hymenoptera to produce a plethora of ABT-888 mw antibiotics to protect their hosts or the host’s food source [7, 20, 21, 40]. Insect symbiosis have been reported more than half a century ago [35] and has regained attention due to the possible exploitation of symbionts for insect pest and/or insect-vectored disease control [8, 30, 41] and the impact they can have on pest- and disease-control programmes [42]. However, the biotechnological potential of bacterial symbionts associated to insects is another face of insect symbioses that is seldom explored, especially the extracellular bacterial symbionts [40, 41, 43, 44]. Furthermore, most of the genera found inhabiting the midgut of the pentatomids

in here studied has already been reported associated with other insects. Some of them have a beneficial impact on the insect fitness, i.e., streptomycetes in hymenopterans [20, 21] Clomifene and corynebacterial GSK2118436 symbionts in Rhodnius spp. [30]. Other genera, such as Dietzia[27, 45] and Brevibacterium[46], have been recently isolated from insects and the last may play a pathogenic association with their hosts [47]. The ecological features of these interactions could be achieved by selective isolation of the symbionts. However, our initial attempts to

culture the actinobacteria associated with a couple of the stinkbugs we have studied by using several selective media for actinobacteria (data not shown) were fruitless so far, indicating a likely intrinsic coevolutionary relationship between these organisms or the environment (insect midgut) have selected actinobacteria species that may require special nutritional requirements. Conclusions Thus, it is clear that the gastric caeca of pentatomids can be considered as an untapped reservoir of putative new species of actinobacteria. The new 16S rRNA gene subclade formed by the IIL-cDm-9s1 phylotype justifies any attempt to isolate and cultivate the actinoflora associated to stinkbugs. Finally, although many have sought to characterize the microbiological diversity in the stinkbug midgut, the simple use of a different primer set demonstrated the existence of a high diversity of an earlier unnoticed group of bacteria, indicating that the interactions between these insects and their symbionts are more complex than previously thought.