Isolation and Identification of Cellulolytic and Lignolytic Bacteria from the Gut Oryctes rhinoceros L. Larvae Decomposition of Oil Palm Empty Fruit Bunches

Abstract

One of the organisms that helps in decomposition of oil palm empty fruit bunches is Oryctes rhinoceros L. larvae. This is because of in the gut of the larvae there are many cellulolytic bacteria and lignoliytic. The process of accelerating the decomposition of oil palm empty fruit bunches into compost can be done by optimizing the work of the bacteria. The aim of this research is to obtain cellulolytic and lignolytic bacteria from larvae O. rhinoceros L.. The research succeeded to isolate 24 isolates of cellulolytic bacteria and lignolytic bacterial isolates from the gut of O. rhinoceros larvae. Based on qualitative test, 9 isolate bacteria produced cellulolytic index above 2. The highest cellulolytic index was generated by ORL19 isolate, while the lignolytic index obtained ORL6 isolate. Based on macroscopic and microscopic identification of bacteria, biochemical and physiological tests, it was found ORL 6 belongs to the genus Bacillus sp. while the ORL 19 belongs to the genus Citrobacter sp..

Transcriptome and microbiome of coconut rhinoceros beetle (Oryctes rhinoceros) larvae

“…Certain microbes do seem to be more prevalent in the Oryctes body compared to the environment. Both Bacillus cereus and Citrobacterer koseri were found in the one previous, culturing-based study of the Oryctes rhinoceros gut by Sari et al [19], and a Citrobacter and Bacillus were also isolated in a recent study using cellulase-agar to selectively enrich cellulolytic microbes [20]. The possibility exists that Citrobacter koseri is a contaminant in our samples, however, as it was present in the negative control.…”

“…Previous research with a related species, Oryctes nasicornis , detected cellulase activity but failed to produce “soluble cellulase” and concluded the cellulolytic ability of that species was microbial in origin [61, 62]. Previous work with Oryctes rhinoceros isolated a cellulolytic Citrobacter and lignolytic Bacillus microbe [20]. Cellulolytic microbes have also been found in other Scarabaeidae beetles, of which the only one related to the microbes we found was Citrobacter freundii [63].…”

“…Disabling the larval ability to detoxify plant secondary compounds or chemical insecticides [18] or their ability to digest food could prove fatal. The possibility exists that Oryctes rhinoceros depends on symbiotic microbes for digestion, especially the production of PCWDEs [13, 19, 20]. Any symbionts would also be targets for control, as knocking out an obligate symbiont with antimicrobials is an effective control of the host insect [18], plus symbionts themselves can be used to mediate RNAi delivery for bioncontrol [21].…”

Culturing-Enriched Metabarcoding Analysis of the Oryctes rhinoceros Gut Microbiome

“…Bacillus cereus is likely a ubiquitous microbial resident of the Oryctes rhinoceros digestive tract, as it or other members of the notoriously genetically similar Bacillus genus [ 36 ] have also been found in all previous studies of this species’ microbiomes [ 13 , 16 , 17 , 18 , 19 ]. While none of our strains produced cellulase with the Congo Red assay, cellulolytic strains of B. cereus exist, so it could provide symbiotic digestive functions to Oryctes .…”

“…and lignolytic Bacillus sp. were isolated in Sumatra, Indonesia [ 18 ]. Species of Citrobacter and Bacillus are almost always found in Oryctes rhinoceros studies, though they are not always checked for enzymatic activity [ 13 , 19 ].…”