Isolation and Characterization of Anaerobic Bacteria for Symbiotic Recycling of Uric Acid Nitrogen in the Gut of Various Termites

Abstract

Recycling of the nitrogenous waste uric acid (UA) of wood-feeding termites by their gut bacteria is one of the significant aspects of symbiosis for the conservation of nitrogen sources. Diverse anaerobic UA-degrading bacteria comprising 16 species were isolated from the gut of eight termite species, and were assigned to Clostridia, Enterobacteriaceae, and low G+C Gram-positive cocci. UA-degrading Clostridia had never been isolated from termite guts. UA-degrading ability was sporadically distributed among phylogenetically various culturable anaerobic bacteria from termite guts. A strain of Clostridium sp., which was commonly isolated from three termite species and represented a probable new species in cluster XIVa of clostridia, utilized UA as a nitrogen source but not as a sole carbon and energy source. This feature is in clear contrast to that of well-studied purinolytic clostridia or previously isolated UA degraders from termite guts, which also utilize UA as a sole carbon and energy source. Ammonia is the major nitrogenous product of UA degradation. Various purines stimulated the growth of this strain when added to an otherwise growth-limiting, nitrogen poor medium. The bacterial species involved the recycling of UA nitrogen in the gut microbial community of termites are more diverse in terms of both taxonomy and nutritional physiology than previously recognized.

Harnessing microfluidic streak plate technique to investigate the gut microbiome of Reticulitermes chinensis

“…These 44 OTUs were assigned to 24 genera. We found that 12 of the 24 genera had been previously observed (Butera, Ferraro, Alonzo, Colazza, & Quatrini, ; Chou, Chen, Arun, & Young, ; Fall et al., ; Hongoh et al., ; Liu et al., ; Shinzato, Muramatsu, Matsui, & Watanabe, ; Thong‐On et al., ) but other 12 genera ( Massilia, Hydrogenophaga, Hydrogenophilus, Neisseria, Helicobacter, Thermomonas, Dokdonella, Acidiphilium, Hyphomicrobium, Paracoccus, Microvirga, and Peredibacter ) had not been reported previously for termite gut microbiota. We also found that there were eight of the 44 OTUs represented possible new taxa, as their 16S rRNA similarities to that of the currently known species were less than 97%.…”

Isolation and assessment of gut bacteria from the Formosan subterranean termite, Coptotermes formosanus (Isoptera: Rhinotermitidae), for paratransgenesis research and application

“…We ultimately chose T. odontotermitis as a candidate to be developed as a “Trojan Horse.” Trabulsiella odontotermitis is termite‐specific and was originally isolated and described from a subterranean termite from the family Termitidae ( Odontotermes formosanus ) (Chou et al ., ). It was also amongst one of the uricolytic bacteria isolated from the termite gut (Thong‐On et al ., ). The whole genome of T. odontotermitis has recently been sequenced which has pointed out many adaptations specific for termite gut environment (Personal communication, Dr. Panagiotis Sapountzis).…”

Biotransformation of Explosives by <b><i>Reticulitermes flavipes</i></b>-Associated Termite Endosymbionts

“…Due to the structural similarity of UA to some explosives, we were interested in determining whether or not the strains isolated in this study were also capable of UA degradation. All isolates were screened for their ability to use UA as described previously [Thong-On et al, 2012], but were found to be negative for this activity (data not shown), indicating UA degradation does not play a role in these isolates ability to transform explosives.…”

“…E. cloacae has been previously isolated from the termite gut and used as a shuttle organism to deliver and spread foreign genes in termite colonies [Husseneder and Grace, 2005;Zhao et al, 2008]. Interestingly, members of the genera Enterobacter, Serratia, and Lactococcus , representing uricolytic isolates, have also been isolated from the hindguts of Reticulitermes [Thong-On et al, 2012]. Uric acid (UA) degrading bacteria have been shown to play a key role in the recycling of nitrogenase waste as termites lack UA utilization activity [Potrikus and Breznak, 1981].…”