Comparison of the bacterial symbiont composition of the Formosan subterranean termite from its native and introduced range (original) (raw)
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The hindgut of feeding termites that feed on wood and litter contains a diverse population of bacteria and protists that contribute to the carbon, nitrogen, and energy requirements of the termite. For understanding the ecological balance in the termite gut, detailed knowledge about the composition of the microbial gut flora is imperative, i.e., the numbers and relative proportions of the microbial taxa and the variability in the microbial composition among different termite colonies and living conditions of termites should be described. Therefore, we isolated and enumerated eight bacterial morphotypes from the gut of the Formosan subterranean termite, Coptotermes formosanus Shiraki. Five morphotypes (three isolates of lactic acid bacteria, isolates of the family Enterobacteriaceae and isolates belonging to the genus Dysgonomonas) were found frequently in all termite colonies. Three additional morphotypes were found sporadically and were considered to be transient flora. We compared the proportions of the three lactic acid bacteria isolates and the Enterobacteriaceae among three different termite colonies. Furthermore, we investigated the shift in proportions of these four major morphotypes depending on whether bacteria were isolated from freshly collected termites or from termites reared in the laboratory under seminatural conditions (in arenas on wood) or artificial conditions (in petri dishes on filter paper). Differences in the culturable microbial composition were not significant among termite colonies, or between field-collected termites and termites reared under seminatural conditions in the laboratory. However, we found significant shifts in the microbial composition between field-collected termites and termites reared on Þlter paper.
Applied and Environmental Microbiology, 2005
We investigated the bacterial gut microbiota from 32 colonies of wood-feeding termites, comprising four Microcerotermes species (Termitidae) and four Reticulitermes species (Rhinotermitidae), using terminal restriction fragment length polymorphism analysis and clonal analysis of 16S rRNA. The obtained molecular community profiles were compared statistically between individuals, colonies, locations, and species of termites. Both analyses revealed that the bacterial community structure was remarkably similar within each termite genus, with small but significant differences between sampling sites and/or termite species. In contrast, considerable differences were found between the two termite genera. Only one bacterial phylotype (defined with 97% sequence identity) was shared between the two termite genera, while 18% and 50% of the phylotypes were shared between two congeneric species in the genera Microcerotermes and Reticulitermes, respectively. Nevertheless, a phylogenetic analysis of 228 phylotypes from Microcerotermes spp. and 367 phylotypes from Reticulitermes spp. with other termite gut clones available in public databases demonstrated the monophyly of many phylotypes from distantly related termites. The monophyletic "termite clusters" comprised of phylotypes from more than one termite species were distributed among 15 bacterial phyla, including the novel candidate phyla TG2 and TG3. These termite clusters accounted for 95% of the 960 clones analyzed in this study. Moreover, the clusters in 12 phyla comprised phylotypes from more than one termite (sub)family, accounting for 75% of the analyzed clones. Our results suggest that the majority of gut bacteria are not allochthonous but are specific symbionts that have coevolved with termites and that their community structure is basically consistent within a genus of termites.
2000
The Formosan subterranean termite, Coptotermes formosanus Shiraki, is a highly destructive invasive pest species in many tropical and subtropical regions. The survival of this termite is dependent on its gut microbes (protozoa and bacteria). Therefore, alternative strategies may be devised in the future using the gut flora of termites as tools and targets for ecologically sound termite control. To facilitate development of such strategies, detailed knowledge of the microbial diversity in the termite gut is sorely needed. Also, it is important to know, which part of the gut flora can be cultured in order to test the physiological contributions of the bacteria to termite survival and to be able to manipulate them, e.g., by genetic engineering. In this study we used culture-independent 16S rDNA sequencing in conjunction with classical culture methods to describe the bacterial species composition in the gut of C. formosanus. The communal bacteria DNA from two termite colonies was extracted, cloned and sequenced. The 105 clones sequenced from both colonies resulted in 12 different bacteria strains from four different groups (Bacteroides, Treponema, Spirochaeta, Clostridiaceae). Bacteroides was the dominant group comprising over 80% of the gut flora in both colonies. The bacteria taxa identified in the gut of C. formosanus using culture-independent 16S rDNA sequencing were different from the bacteria we were able to culture from the gut of the same species. To date, we have cultured over 25 strains of bacteria, including species belonging to the Enterobacteriacea, Bacteroidales and Lactobacillales. All of the species identified by their 16S sequences and most of the cultured strains were novel species found exclusively in the termite gut. Bacteria culture and culture-independent techniques identified different parts of the termites' gut community. Thus, it is recommended to use both methods in a complementary way to describe the microbial diversity and ecology in the termite gut.
Applied and Environmental Microbiology, 2007
In tropical ecosystems, termite mound soils constitute an important soil compartment covering around 10% of African soils. Previous studies have shown (S. Fall, S. Nazaret, J. L. Chotte, and A. Brauman, Microb. Ecol. 28:191-199, 2004) that the bacterial genetic structure of the mounds of soil-feeding termites (Cubitermes niokoloensis) is different from that of their surrounding soil. The aim of this study was to characterize the specificity of bacterial communities within mounds with respect to the digestive and soil origins of the mound. We have compared the bacterial community structures of a termite mound, termite gut sections, and surrounding soil using PCR-denaturing gradient gel electrophoresis (DGGE) analysis and cloning and sequencing of PCR-amplified 16S rRNA gene fragments. DGGE analysis revealed a drastic difference between the genetic structures of the bacterial communities of the termite gut and the mound. Analysis of 266 clones, including 54 from excised bands, revealed a high level of diversity in each biota investigated. The soil-feeding termite mound was dominated by the Actinobacteria phylum, whereas the Firmicutes and Proteobacteria phyla dominate the gut sections of termites and the surrounding soil, respectively. Phylogenetic analyses revealed a distinct clustering of Actinobacteria phylotypes between the mound and the surrounding soil. The Actinobacteria clones of the termite mound were diverse, distributed among 10 distinct families, and like those in the termite gut environment lightly dominated by the Nocardioidaceae family. Our findings confirmed that the soil-feeding termite mound (C. niokoloensis) represents a specific bacterial habitat in the tropics.
Microbial Ecology, 2012
Termites inhabit tropical and subtropical areas where they contribute to structure and composition of soils by efficiently degrading biomass with aid of resident gut microbiota. In this study, culture-independent molecular analysis was performed based on bacterial and archaeal 16S rRNA clone libraries to describe the gut microbial communities within Cornitermes cumulans, a South American litter-feeding termite. Our data reveal extensive bacterial diversity, mainly composed of organisms from the phyla Spirochaetes, Bacteroidetes, Firmicutes, Actinobacteria, and Fibrobacteres. In contrast, a low diversity of archaeal 16S rRNA sequences was found, comprising mainly members of the Crenarchaeota phylum.
PLOS ONE, 2015
Previous surveys of the gut microbiota of termites have been limited to the worker caste. Termite gut microbiota has been well documented over the last decades and consists mainly of lineages specific to the gut microbiome which are maintained across generations. Despite this intimate relationship, little is known of how symbionts are transmitted to each generation of the host, especially in higher termites where proctodeal feeding has never been reported. The bacterial succession across life stages of the wood-feeding higher termite Nasutitermes arborum was characterized by 16S rRNA gene deep sequencing. The microbial community in the eggs, mainly affiliated to Proteobacteria and Actinobacteria, was markedly different from the communities in the following developmental stages. In the first instar and last instar larvae and worker caste termites, Proteobacteria and Actinobacteria were less abundant than Firmicutes, Bacteroidetes, Spirochaetes, Fibrobacteres and the candidate phylum TG3 from the last instar larvae. Most of the representatives of these phyla (except Firmicutes) were identified as termite-gut specific lineages, although their relative abundances differed. The most salient difference between last instar larvae and worker caste termites was the very high proportion of Spirochaetes, most of which were affiliated to the Treponema Ic, Ia and If subclusters, in workers. The results suggest that termite symbionts are not transmitted from mother to offspring but become established by a gradual process allowing the offspring to have access to the bulk of the microbiota prior to the emergence of workers, and, therefore, presumably through social exchanges with nursing workers.
Extremophiles, 2005
The first proctodeal (P1) segment in the hindgut of certain higher termites shows high alkalinity. We examined the bacterial diversity of the alkaline P1 gut segments of four species of higher termites by T-RFLP and phylogenetic analyses based on PCR-amplified 16S rRNA genes. The bacterial community of the P1 segment was apparently different from that of the whole gut in each termite. Sequence analysis revealed that Firmicutes (Clostridia and Bacilli) were dominant in the P1 segments of all four termites; however, the phylogenetic compositions varied among the termites. Although some of the P1 segment-derived sequences were related to the sequences previously reported from the alkaline digestive tracts of other insects, most of them formed phylogenetic clusters unique to termites. Such “termite P1 clusters” were distantly related to known bacterial species as well as to sequences reported from alkaline environments in nature. We successfully obtained enrichment cultures of Clostridia- and Bacilli-related bacteria, including putative novel species under anaerobic alkaline conditions from the termite guts. Our results suggest that the alkaline gut region of termites harbors unique bacterial lineages and are expected to be a rich reservoir of novel alkaliphiles yet to be cultivated.
SpringerPlus, 2015
Termites constitute part of diverse and economically important termite fauna in Africa, but information on gut microbiota and their associated soil microbiome is still inadequate. In this study, we assessed and compared the bacterial diversity and community structure between termites' gut, their mounds and surrounding soil using the 454 pyrosequencing-based analysis of 16S rRNA gene sequences. A wood-feeder termite (Microcerotermes sp.), three fungus-cultivating termites (Macrotermes michaelseni, Odontotermes sp. and Microtermes sp.), their associated mounds and corresponding savannah soil samples were analyzed. The pH of the gut homogenates and soil physico-chemical properties were determined. The results indicated significant difference in bacterial community composition and structure between the gut and corresponding soil samples. Soil samples (Chao1 index ranged from 1359 to 2619) had higher species richness than gut samples (Chao1 index ranged from 461 to 1527). The bacterial composition and community structure in the gut of Macrotermes michaelseni and Odontotermes sp. were almost identical but different from that of Microtermes and Microcerotermes species, which had unique community structures. The most predominant bacterial phyla in the gut were Bacteroidetes (40-58 %), Spirochaetes (10-70 %), Firmicutes (17-27 %) and Fibrobacteres (13 %) while in the soil samples were Acidobacteria (28-45 %), Actinobacteria (20-40 %) and Proteobacteria (18-24 %). Some termite gut-specific bacterial lineages belonging to the genera Dysgonomonas, Parabacteroides, Paludibacter, Tannerella, Alistipes, BCf9-17 termite group and Termite Treponema cluster were observed. The results not only demonstrated a high level of bacterial diversity in the gut and surrounding soil environments, but also presence of distinct bacterial communities that are yet to be cultivated. Therefore, combined efforts using both culture and culture-independent methods are suggested to comprehensively characterize the bacterial species and their specific roles in these environments.
Microbiome, 2015
Background: Termites and their microbial gut symbionts are major recyclers of lignocellulosic biomass. This important symbiosis is obligate but relatively open and more complex in comparison to other well-known insect symbioses such as the strict vertical transmission of Buchnera in aphids. The relative roles of vertical inheritance and environmental factors such as diet in shaping the termite gut microbiome are not well understood. Results: The gut microbiomes of 66 specimens representing seven higher and nine lower termite genera collected in Australia and North America were profiled by small subunit (SSU) rRNA amplicon pyrosequencing. These represent the first reported culture-independent gut microbiome data for three higher termite genera: Tenuirostritermes, Drepanotermes, and Gnathamitermes; and two lower termite genera: Marginitermes and Porotermes. Consistent with previous studies, bacteria comprise the largest fraction of termite gut symbionts, of which 11 phylotypes (6 Treponema, 1 Desulfarculus-like, 1 Desulfovibrio, 1 Anaerovorax-like, 1 Sporobacter-like, and 1 Pirellula-like) were widespread occurring in ≥50% of collected specimens. Archaea are generally considered to comprise only a minority of the termite gut microbiota (<3%); however, archaeal relative abundance was substantially higher and variable in a number of specimens including Macrognathotermes, Coptotermes, Schedorhinotermes, Porotermes, and Mastotermes (representing up to 54% of amplicon reads). A ciliate related to Clevelandella was detected in low abundance in Gnathamitermes indicating that protists were either reacquired after protists loss in higher termites or persisted in low numbers across this transition. Phylogenetic analyses of the bacterial communities indicate that vertical inheritance is the primary force shaping termite gut microbiota. The effect of diet is secondary and appears to influence the relative abundance, but not membership, of the gut communities.
Frontiers in microbiology, 2017
The gut microbiome of lower termites comprises protists and bacteria that help these insects to digest cellulose and to thrive on wood. The composition of the termite gut microbiome correlates with phylogenetic distance of the animal host and host ecology (diet) in termites collected from their natural environment. However, carryover of transient microbes from host collection sites are an experimental concern and might contribute to the ecological imprints on the termite gut microbiome. Here, we set out to test whether an ecological imprint on the termite gut microbiome remains, when focusing on the persistent microbiome. Therefore, we kept five termite species under strictly controlled dietary conditions and subsequently profiled their protist and bacterial gut microbial communities using 18S and 16S rRNA gene amplicon sequencing. The species differed in their ecology; while three of the investigated species were wood-dwellers that feed on the piece of wood they live in and never l...