Diversity and Antimicrobial Activity of Actinomycetes from Fecal Sample of Rhinoceros Beetle Larvae

Abstract

Actinomycetes produce diverse secondary metabolites which have the primary importance in medicine, agriculture and food production, and key to this is their ability to interact with other organisms in natural habitats. In this study, we have investigated the taxonomical and functional diversity of actinomycetes in fecal sample of rhinoceros beetle larvae (Allomyrina dichotoma L.) by using culture-dependent and -independent approaches. For the culture-independent approach, the community DNA was extracted from the sample and 16S rRNA genes of actinomycetes were amplified using actinomycetes-specific PCR primers. Thirty-seven clones were classified into 15 genera and 24 species of actinomycetes. For the culture-dependent approach, 53 strains were isolated from larval feces, of which 27 isolates were selected based on morphological characteristics. The isolates were classified into 4 genera and 14 species, and 24 isolates (89%) were identified as the genus Streptomyces. Many of the representative isolates had antimicrobial activities against plant pathogenic fungi and Gram-positive bacteria. In addition, most of the isolates (78%) showed biochemical properties to hydrolyze cellulose and casein. The results demonstrated that diverse and valuable actinomycetes could be isolated from insect fecal samples, indicating that insect guts can be rich sources for novel bioactive compounds.

Identification and Antibacterial Activity of Streptomyces mediolani CF51DZ Isolated from the Beetle (Protaetia morio), Collected from Souk Ahras, North-East of Algeria

“…The strain Streptomyces antibiotics ess_am A8 isolated from the ant Tapinoma simrothi was tested for the antimicrobial activity, inhibiting the Escherichia coli ATCC 7839, Pseudomonas aeruginosa ATCC 9027, Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 6538, Aspergillus flavus, Fusarium moniliforme, Aspergillus niger and Candida albicans. 18 Earlier reports of Hye-Won et al, 31 Anand and Kumaresh, 38 and Liu et al 39 support our results reporting an antimicrobial activity of the actinomycetes, especially Streptomyces strains isolated from various sources.…”

“…29,30 It was reported also that 78% of Streptomyces isolates from the feces of rhinoceros beetle larvae (Allomyrina dichotoma L.) are able to hydrolyze cellulose and casein owed to their typical biochemical properties. 31 Recently, the actinomycetes were molecularly identified by using 16S rRNA gene analysis of actinomycetes. 32 Similar previous works have reported the utility of molecular analysis of 16S rRNA in the identification of actinomycetes.…”

“…32 Similar previous works have reported the utility of molecular analysis of 16S rRNA in the identification of actinomycetes. 26,33,34 In this context, Hye-Won et al 31 have isolated and identified 53 strains of Streptomyces from the feces of rhinoceros beetle larvae (Allomyrina dichotoma L.). These isolates exhibited antimicrobial activities against phytopathogenic fungi and Gram-positive bacteria.…”

The power of poop: Defecation behaviors and social hygiene in insects

“…Gut and fecal microbiomes of wood-feeding larvae of the longhorn beetle Cerambyx welensii harbor multiple actinobacterial strains producing a wide range of antimicrobial compounds ( Fig 1 ), including several with broad ranges of bioactivities against potential pathogens [ 27 ]. Antifungal properties of fecal isolates from the herbivorous rhinoceros beetle Allomyrina dichotoma [ 28 ] and bark beetle Dendroctonus rufipennis ( Fig 1 ) [ 29 ] suggest that actinobacteria might play a wider role in reducing pathogen load in gut microbiomes of lignocellulose-feeding beetles. Finally, in the Eastern subterranean termite, Reticulitermes flavipes , actinobacteria have been found in feces-lined galleries, surrounding soils, and on the termite cuticle; considering the occurrence of grooming and coprophagy in termites, it is possible that actinobacteria are cycled throughout the colonies and nests themselves [ 30 ].…”