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Inagaki T, Igai K, Takahashi K, Hongoh Y. Transmission dynamics of symbiotic protist communities in the termite gut: association with host adult eclosion and dispersal. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231527. [PMID: 38716332 PMCID: PMC11076123 DOI: 10.1098/rsos.231527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 02/21/2024] [Accepted: 03/07/2024] [Indexed: 07/31/2024]
Abstract
The fidelity of vertical transmission is a critical factor in maintaining mutualistic associations with microorganisms. The obligate mutualism between termites and intestinal protist communities has been maintained for over 130 million years, suggesting the faithful transmission of diverse protist species across host generations. Although a severe bottleneck can occur when alates disperse with gut protists, how protist communities are maintained during this process remains largely unknown. In this study, we examined the dynamics of intestinal protist communities during adult eclosion and alate dispersal in the termite Reticulitermes speratus. We found that the protist community structure in last-instar nymphs differed significantly from that in workers and persisted intact during adult eclosion, whereas all protists disappeared from the gut during moults between worker stages. The number of protists in nymphs and alates was substantially lower than in workers, whereas the proportion of protist species exhibiting low abundance in workers was higher in nymphs and alates. Using a simulation-based approach, we demonstrate that such changes in the protist community composition of nymphs and alates improve the transmission efficiency of whole protist species communities. This study thus provides novel insights into how termites have maintained mutualistic relationships with diverse gut microbiota for generations.
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Affiliation(s)
- Tatsuya Inagaki
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan
- Department of Entomology, Cornell University, Ithaca, NY, USA
| | - Katsura Igai
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan
| | - Kazuki Takahashi
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan
| | - Yuichi Hongoh
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan
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2
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Dar MA, Xie R, Zabed HM, Ali S, Zhu D, Sun J. Termite Microbial Symbiosis as a Model for Innovative Design of Lignocellulosic Future Biorefinery: Current Paradigms and Future Perspectives. BIOMASS 2024; 4:180-201. [DOI: 10.3390/biomass4010009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/23/2024]
Abstract
The hunt for renewable and alternative fuels has driven research towards the biological conversion of lignocellulosic biomass (LCB) into biofuels, including bioethanol and biohydrogen. Among the natural biomass utilization systems (NBUS), termites represent a unique and easy-to-access model system to study host–microbe interactions towards lignocellulose bioconversion/valorization. Termites have gained significant interest due to their highly efficient lignocellulolytic systems. The wood-feeding termites apply a unique and stepwise process for the hydrolysis of lignin, hemicellulose, and cellulose via biocatalytic processes; therefore, mimicking their digestive metabolism and physiochemical gut environments might lay the foundation for an innovative design of nature-inspired biotechnology. This review highlights the gut system of termites, particularly the wood-feeding species, as a unique model for future biorefinery. The gut system of termites is a treasure-trove for prospecting novel microbial species, including protists, bacteria, and fungi, having higher biocatalytic efficiencies and biotechnological potentials. The significance of potential bacteria and fungi for harnessing the enzymes appropriate for lignocellulosic biorefinery is also discussed. Termite digestomes are rich sources of lignocellulases and related enzymes that could be utilized in various industrial processes and biomass-related applications. Consideration of the host and symbiont as a single functioning unit will be one of the most crucial strategies to expedite developments in termite-modeled biotechnology in the future.
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Affiliation(s)
- Mudasir A. Dar
- Biofuels Institute, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Rongrong Xie
- Biofuels Institute, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Hossain M. Zabed
- School of Life Science, Guangzhou University, 230 Wai Huan Xi Road, Guangzhou 510006, China
| | - Shehbaz Ali
- Biofuels Institute, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Daochen Zhu
- Biofuels Institute, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Jianzhong Sun
- Biofuels Institute, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
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3
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Tuzlak L, Alves-Ferreira EVC, Schwartz CL, Kennard A, Leung JM, Shehata C, Grigg ME. Fine structure and molecular characterization of two new parabasalid species that naturally colonize laboratory mice, Tritrichomonas musculus and Tritrichomonas casperi. J Eukaryot Microbiol 2023; 70:e12989. [PMID: 37300520 DOI: 10.1111/jeu.12989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 05/10/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023]
Abstract
Tritrichomonas muris is a common flagellated protist isolated from the cecum of wild rodents. This commensal protist has been shown previously to alter immune phenotypes in laboratory mice. Other trichomonads, referred to as Tritrichomonas musculis and Tritrichomonas rainier, also naturally colonize laboratory mice and cause immune alterations. This report formally describes two new trichomonads, Tritrichomonas musculus n. sp., and Tritrichomonas casperi n. sp., at the ultrastructural and molecular level. These two protists were isolated from laboratory mice and were differentiated by their size and the structure of their undulating membrane and posterior flagellum. Analysis at the 18S rRNA and trans-ITS genetic loci supported their designation as distinct species, related to T. muris. To assess the true extent of parabasalid diversity infecting laboratory mice, 135 mice bred at the National Institutes of Health (NIH) were screened using pan-parabasalid primers that amplify the trans-ITS region. Forty-four percent of mice were positive for parabasalids, encompassing a total of eight distinct sequence types. Tritrichomonas casperi and Trichomitus-like protists were dominant. T. musculus and T. rainier were also detected, but T. muris was not. Our work establishes a previously underappreciated diversity of commensal trichomonad flagellates that naturally colonize the enteric cavity of laboratory mice.
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Affiliation(s)
- Leila Tuzlak
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, USA
| | - Eliza V C Alves-Ferreira
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, USA
| | - Cindi L Schwartz
- Electron Microscopy Unit, Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, USA
| | - Andrea Kennard
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, USA
| | - Jacqueline M Leung
- Electron Microscopy Unit, Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, USA
| | - Christina Shehata
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, USA
| | - Michael E Grigg
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, USA
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4
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Blanton AG, Perkins S, Peterson BF. In vitro assays reveal inherently insecticide-tolerant termite symbionts. Front Physiol 2023; 14:1134936. [PMID: 37501931 PMCID: PMC10368989 DOI: 10.3389/fphys.2023.1134936] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 06/30/2023] [Indexed: 07/29/2023] Open
Abstract
Introduction: Termite symbionts are well known for conferring a myriad of benefits to their hosts. Bacterial symbionts are repeatedly associated with increased fitness, nutritional supplementation, pathogen protection, and proper development across insect taxa. In addition, several recent studies link bacterial symbionts to reduced insecticide efficacy. This has important implications both in pest control management and environmental bioremediation efforts. Insects' guts may be a valuable resource for microbes with broad application given their unique niches and metabolic diversity. Though insecticide resistance in termites is considered unlikely due to their life history, the close association of termites with a multitude of bacteria raises the question: is there potential for symbiont-mediated pesticide tolerance in termites? Methods and results: We identified a candidate that could grow in minimal medium containing formulated pesticide. This bacterial isolate was then subjected to continuous culture and subsequently demonstrated improved performance in the presence of pesticide. Isolates subjected to continuous culture were then grown at a range of concentrations from 1-10X the formulation rate. After constant exposure for several generations, isolates grew significantly better. Conclusion: Here we demonstrate that naïve insect hosts can harbor symbionts with inherent insecticide tolerance capable of rapid adaptation to increasing insecticide concentrations overtime. This has broad implications for both pest control and environmental cleanup of residual pesticides.
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Tuzlak L, Alves-Ferreira EV, Kennard A, Shehata C, Schwartz CL, Grigg ME. Ultrastructural identification and molecular characterization of two new parabasalid species that naturally colonize laboratory mice, Tritrichomonas musculus and Tritrichomonas casperi. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.20.524969. [PMID: 36789430 PMCID: PMC9928039 DOI: 10.1101/2023.01.20.524969] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Tritrichomonas muris is a flagellated protist isolated from the cecum of wild mice in the Czech Republic. This commensal protist has been shown previously to alter immune phenotypes in laboratory mice. Other trichomonads, previously referred to as Tritrichomonas musculis and Tritrichomonas rainier , also naturally colonize laboratory mice and cause immune alterations. This report formally describes two new trichomonads, Tritrichomonas musculus n. sp., and Tritrichomonas casperi n. sp., at the ultrastructural and molecular level. These two protists were isolated from laboratory mice, and were differentiated by their size and the structure of their undulating membrane and posterior flagellum. Analysis at the 18S rRNA and trans- ITS genetic loci supported their designation as distinct species, related to T. muris . To further assess the true extent of parabasalid diversity infecting laboratory mice, 135 mice were screened at the NIH using pan-parabasalid primers that amplify the trans- ITS region. Forty-four percent of mice were positive for parabasalids, encompassing a total of 8 distinct sequence types. Tritrichomonas casperi and Trichomitus- like protists were dominant. T. musculus and T. rainier were also detected, but T. muris was not. Our work establishes a previously underappreciated diversity of commensal trichomonad protists that naturally colonize the enteric cavity of laboratory mice.
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Affiliation(s)
- Leila Tuzlak
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, 20892, USA
| | - Eliza V.C. Alves-Ferreira
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, 20892, USA
| | - Andrea Kennard
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, 20892, USA
| | - Christina Shehata
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, 20892, USA
| | - Cindi L. Schwartz
- Electron Microscopy Unit, Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, 59840, USA
| | - Michael E. Grigg
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, 20892, USA
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6
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Tang YL, Kong YH, Qin S, Merchant A, Shi JZ, Zhou XG, Li MW, Wang Q. Transcriptomic dissection of termite gut microbiota following entomopathogenic fungal infection. Front Physiol 2023; 14:1194370. [PMID: 37153226 PMCID: PMC10161392 DOI: 10.3389/fphys.2023.1194370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 04/14/2023] [Indexed: 05/09/2023] Open
Abstract
Termites are social insects that live in the soil or in decaying wood, where exposure to pathogens should be common. However, these pathogens rarely cause mortality in established colonies. In addition to social immunity, the gut symbionts of termites are expected to assist in protecting their hosts, though the specific contributions are unclear. In this study, we examined this hypothesis in Odontotermes formosanus, a fungus-growing termite in the family Termitidae, by 1) disrupting its gut microbiota with the antibiotic kanamycin, 2) challenging O. formosanus with the entomopathogenic fungus Metarhizium robertsii, and finally 3) sequencing the resultant gut transcriptomes. As a result, 142531 transcripts and 73608 unigenes were obtained, and unigenes were annotated following NR, NT, KO, Swiss-Prot, PFAM, GO, and KOG databases. Among them, a total of 3,814 differentially expressed genes (DEGs) were identified between M. robertsii infected termites with or without antibiotics treatment. Given the lack of annotated genes in O. formosanus transcriptomes, we examined the expression profiles of the top 20 most significantly differentially expressed genes using qRT-PCR. Several of these genes, including APOA2, Calpain-5, and Hsp70, were downregulated in termites exposed to both antibiotics and pathogen but upregulated in those exposed only to the pathogen, suggesting that gut microbiota might buffer/facilitate their hosts against infection by finetuning physiological and biochemical processes, including innate immunity, protein folding, and ATP synthesis. Overall, our combined results imply that stabilization of gut microbiota can assist termites in maintaining physiological and biochemical homeostasis when foreign pathogenic fungi invade.
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Affiliation(s)
- Ya-ling Tang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu Province, China
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yun-hui Kong
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu Province, China
| | - Sheng Qin
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu Province, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang, Jiangsu Province, China
| | - Austin Merchant
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - Ji-zhe Shi
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - Xu-guo Zhou
- Department of Entomology, University of Kentucky, Lexington, KY, United States
- *Correspondence: Xu-guo Zhou, ; Mu-wang Li, ; Qian Wang,
| | - Mu-wang Li
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu Province, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang, Jiangsu Province, China
- *Correspondence: Xu-guo Zhou, ; Mu-wang Li, ; Qian Wang,
| | - Qian Wang
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
- *Correspondence: Xu-guo Zhou, ; Mu-wang Li, ; Qian Wang,
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7
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Wolfe ZM, Scharf ME. Microbe-mediated activation of indoxacarb in German cockroach (Blattella germanica L.). PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 188:105234. [PMID: 36464351 DOI: 10.1016/j.pestbp.2022.105234] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/02/2022] [Accepted: 09/09/2022] [Indexed: 06/17/2023]
Abstract
The German cockroach (Blattella germanica L.) is a major urban pest worldwide and is notorious for its ability to detoxify and resist insecticides. German cockroaches have generalist feeding habits that expose them to a range of potential hazardous substances and host a wide variety of unique microbial species, which may potentially facilitate unique detoxification capabilities. Since field German cockroach populations are routinely exposed to both bait and spray insecticide treatments, we hypothesized whether these unique gut microbes might play roles in toxicological processes of the host insect. The goals of this research were to understand the metabolic processes inside the German cockroach gut after treatment with kanamycin, a broad-ranging antibiotic, and indoxacarb, an oxadiazine pro-insecticide used in cockroach bait products. In these experiments, two resistant cockroach strains were obtained from field populations in Danville, IL and compared to a susceptible laboratory strain that had no previous exposure to insecticides (J-wax). Roaches provided kanamycin-infused water had lower median mortality to indoxacarb compared to the control treatment in feeding bioassays regardless of strain, but in vial (surface contact) bioassays, only susceptible cockroaches experienced a shift in mortality apparently due to their greater susceptibility. When frass extracts of indoxacarb-fed cockroaches were analyzed, less of the active, hydrolytic metabolite DCJW (N-decarbomethoxyllated JW062) was produced relative to the parent compound indoxacarb with the antibiotic KAN. This result was further corroborated by hydrolase activity assays of whole homogenized cockroach guts. Taken together these results provide novel evidence of microbe-mediated pro-insecticide activation in the cockroach gut.
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Affiliation(s)
- Zachery M Wolfe
- Department of Entomology, Purdue University, West Lafayette, IN 47907, USA.
| | - Michael E Scharf
- Department of Entomology, Purdue University, West Lafayette, IN 47907, USA.
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8
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Chen J, Gissendanner CR, Tikhe CV, Li HF, Sun Q, Husseneder C. Genomics and Geographic Diversity of Bacteriophages Associated With Endosymbionts in the Guts of Workers and Alates of Coptotermes Species (Blattodea: Rhinotermitidae). Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.881538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Subterranean termites depend nutritionally on their gut microbiota, which includes protozoa as well as taxonomically and functionally diverse bacteria. Our previous metavirome study revealed a high diversity and novel families of bacteriophages in the guts of Coptotermes formosanus workers from New Orleans, Louisiana, United States. Two assembled bacteriophage genomes (Phages TG-crAlp-04 and 06, family Podoviridae) existed in all colonies and showed similarity to a prophage (ProJPt-Bp1) previously sequenced from a bacterial endosymbiont (Candidatus Azobacteroides pseudotrichonymphae, CAP) of protozoa in the gut of a termite species of the genus Prorhinotermes from Taiwan. In this study the genomes of Phage TG-crAlp-04 and 06 were subjected to detailed functional annotation. Both phage genomes contained conserved genes for DNA packaging, head and tail morphogenesis, and phage replication. Approximately 30% of the amino acid sequences derived from genes in both genomes matched to those of ProJPt-Bp1 phage or other phages from the crAss-like phage group. No integrase was identified; the lack of a lysogeny module is a characteristic of crAss-like phages. Primers were designed to sequence conserved genes of the two phages and their putative host bacterium (CAP) to detect their presence in different termite species from native and introduced distribution ranges. Related strains of the host bacterium were found across different termite genera and geographic regions. Different termite species had separate CAP strains, but intraspecific geographical variation was low. These results together with the fact that CAP is an important intracellular symbiont of obligate cellulose-digesting protozoa, suggest that CAP is a core gut bacterium and co-evolved across several subterranean termite species. Variants of both crAss-like phages were detected in different Coptotermes species from the native and introduced range, but they did not differentiate by species or geographic region. Since similar phages were detected in different termite species, we propose the existence of a core virome associated with core bacterial endosymbionts of protozoa in the guts of subterranean termites. This work provides a strong basis for further study of the quadripartite relationship of termites, protozoa, bacteria, and bacteriophages.
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Sapkota R, Scharf ME. Intercolony Comparisons of Gut Microbiome Composition From Lab Reared Eastern Subterranean Termites (Blattodea: Rhinotermitidae). JOURNAL OF INSECT SCIENCE (ONLINE) 2022; 22:9. [PMID: 35381082 PMCID: PMC8982785 DOI: 10.1093/jisesa/ieac015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Indexed: 06/14/2023]
Abstract
Termites are social insects living in colonies composed of worker, soldier, and reproductive castes. Termite hindguts are inhabited by all three domains of life- Eukarya (protists), Bacteria, and Archaea. These gut microorganisms are horizontally and vertically transferred by nestmates and reproductives, respectively. Prior evidence suggests that every colony potentially has a different gut microbiome that was transferred vertically and horizontally over time. However, we do not know if different colonies reared in the laboratory on the same diet will ultimately demonstrate similar microbial composition and structure. Therefore, we looked at gut bacteria in Eastern subterranean termite (Reticulitermes flavipes) colonies that were reared in the laboratory with identical diets and rearing conditions. Based on16S rRNA gene sequencing, the observed features, and Shannon's diversity were significantly different between the colonies while differences in Pielou evenness and Faith phylogenetic diversity were not statistically significant. In addition, the microbial community structures were significantly different between colonies. Based on ANCOM (Analysis of Composition of Microbiomes), the taxa Elizabethkingia (Bacteroidetes: Flavobacteriales) and Chryseobacterium (Bacteroidetes: Flavobacteriales) were differentially abundant between the colonies. These results suggest that providing the exact same diet and rearing environment for >2 yr cannot result in identical gut microbiomes between termite colonies.
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Affiliation(s)
- R Sapkota
- Department of Entomology, Purdue University, West Lafayette, IN, USA
| | - M E Scharf
- Department of Entomology, Purdue University, West Lafayette, IN, USA
- Entomology and Nematology Department, University of Florida, Gainesville, FL, USA
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10
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Afzal M, Shaheen N, Shah SAA, Iqbal A, Scharf ME, Qureshi NA. Saccharification of agricultural lignocellulosic feedstocks by endogenous and symbiotic cellulases from the subterranean termites. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2021.102265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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11
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Wolfe ZM, Scharf ME. Differential microbial responses to antibiotic treatments by insecticide-resistant and susceptible cockroach strains (Blattella germanica L.). Sci Rep 2021; 11:24196. [PMID: 34921232 PMCID: PMC8683489 DOI: 10.1038/s41598-021-03695-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 12/08/2021] [Indexed: 01/24/2023] Open
Abstract
The German cockroach (Blattella germanica L.) is a major urban pest worldwide and is known for its ability to resist insecticides. Past research has shown that gut bacteria in other insects can metabolize xenobiotics, allowing the host to develop resistance. The research presented here determined differences in gut microbial composition between insecticide-resistant and susceptible German cockroaches and compared microbiome changes with antibiotic treatment. Cockroaches received either control diet or diet plus kanamycin (KAN) to quantify shifts in microbial composition. Additionally, both resistant and susceptible strains were challenged with diets containing the insecticides abamectin and fipronil in the presence and absence of antibiotic. In both strains, KAN treatment reduced feeding, leading to higher doses of abamectin and fipronil being tolerated. However, LC50 resistance ratios between resistant and susceptible strains decreased by half with KAN treatment, suggesting gut bacteria mediate resistance. Next, whole guts were isolated, bacterial DNA extracted, and 16S MiSeq was performed. Unlike most bacterial taxa, Stenotrophomonas increased in abundance in only the kanamycin-treated resistant strain and was the most indicative genus in classifying between control and kanamycin-treated cockroach guts. These findings provide unique insights into how the gut microbiome responds to stress and disturbance, and important new insights into microbiome-mediated insecticide resistance.
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Affiliation(s)
- Zachery M Wolfe
- Department of Entomology, Purdue University, West Lafayette, IN, 47907, USA.
| | - Michael E Scharf
- Department of Entomology, Purdue University, West Lafayette, IN, 47907, USA
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12
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Wu CY, Meng J, Merchant A, Zhang YX, Li MW, Zhou XG, Wang Q. Microbial Response to Fungal Infection in a Fungus-Growing Termite, Odontotermes formosanus (Shiraki). Front Microbiol 2021; 12:723508. [PMID: 34880836 PMCID: PMC8645866 DOI: 10.3389/fmicb.2021.723508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 11/01/2021] [Indexed: 12/12/2022] Open
Abstract
The crosstalk between gut microbiota and host immunity has emerged as one of the research foci of microbiome studies in recent years. The purpose of this study was to determine how gut microbes respond to fungal infection in termites, given their reliance on gut symbionts for food intake as well as maintaining host health. Here, we used Metarhizium robertsii, an entomopathogenic fungus, to infect Odontotermes formosanus, a fungus-growing termite in the family Termitidae, and documented changes in host gut microbiota via a combination of bacterial 16S rDNA sequencing, metagenomic shotgun sequencing, and transmission electron microscopy. Our analyses found that when challenged with Metarhizium, the termite gut showed reduced microbial diversity within the first 12 h of fungal infection and then recovered and even surpassed pre-infection flora levels. These combined results shed light on the role of gut flora in maintaining homeostasis and immune homeostasis in the host, and the impact of gut flora dysbiosis on host susceptibility to infection.
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Affiliation(s)
- Chen-Yu Wu
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China.,School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
| | - Jing Meng
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Austin Merchant
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - Yi-Xiang Zhang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Mu-Wang Li
- School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
| | - Xu-Guo Zhou
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - Qian Wang
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
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13
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Sapkota R, Nakatsu CH, Scharf ME. Regulation of host phenotypic plasticity by gut symbiont communities in the eastern subterranean termite (Reticulitermes flavipes). J Exp Biol 2021; 224:272131. [PMID: 34515310 DOI: 10.1242/jeb.242553] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 09/06/2021] [Indexed: 12/22/2022]
Abstract
Termites are eusocial insects that host a range of prokaryotic and eukaryotic gut symbionts and can differentiate into a range of caste phenotypes. Soldier caste differentiation from termite workers follows two successive molts (worker-presoldier-soldier) that are driven at the endocrine level by juvenile hormone (JH). Although physiological and eusocial mechanisms tied to JH signaling have been studied, the role of gut symbionts in the caste differentiation process is poorly understood. Here, we used the JH analog methoprene in combination with the antibiotic kanamycin to manipulate caste differentiation and gut bacterial loads in Reticulitermes flavipes termites via four bioassay treatments: kanamycin, methoprene, kanamycin+methoprene, and an untreated (negative) control. Bioassay results demonstrated a significantly higher number of presoldiers in the methoprene treatment, highest mortality in kanamycin+methoprene treatment, and significantly reduced protist numbers in all treatments except the untreated control. Bacterial 16S rRNA gene sequencing provided alpha and beta diversity results that mirrored bioassay findings. From ANCOM analysis, we found that several bacterial genera were differentially abundant among treatments. Finally, follow-up experiments showed that if methoprene and kanamycin or untreated termites are placed together, zero or rescued presoldier initiation, respectively, occurs. These findings reveal that endogenous JH selects for symbiont compositions required to successfully complete presoldier differentiation. However, if the gut is voided before the influx of JH, it cannot select for the necessary symbionts that are crucial for molting. Based on these results, we are able to provide a novel example of linkages between gut microbial communities and host phenotypic plasticity.
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Affiliation(s)
- Rajani Sapkota
- Department of Entomology, Purdue University, West Lafayette IN 47907, USA
| | - Cindy H Nakatsu
- Department of Agronomy, College of Agriculture, Purdue University, West Lafayette IN 47907, USA
| | - Michael E Scharf
- Department of Entomology, Purdue University, West Lafayette IN 47907, USA
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Scharf ME, Peterson BF. A Century of Synergy in Termite Symbiosis Research: Linking the Past with New Genomic Insights. ANNUAL REVIEW OF ENTOMOLOGY 2021; 66:23-43. [PMID: 33417825 DOI: 10.1146/annurev-ento-022420-074746] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Termites have long been studied for their symbiotic associations with gut microbes. In the late nineteenth century, this relationship was poorly understood and captured the interest of parasitologists such as Joseph Leidy; this research led to that of twentieth-century biologists and entomologists including Cleveland, Hungate, Trager, and Lüscher. Early insights came via microscopy, organismal, and defaunation studies, which led to descriptions of microbes present, descriptions of the roles of symbionts in lignocellulose digestion, and early insights into energy gas utilization by the host termite. Focus then progressed to culture-dependent microbiology and biochemical studies of host-symbiont complementarity, which revealed specific microhabitat requirements for symbionts and noncellulosic mechanisms of symbiosis (e.g., N2 fixation). Today, knowledge on termite symbiosis has accrued exponentially thanks to omic technologies that reveal symbiont identities, functions, and interdependence, as well as intricacies of host-symbiont complementarity. Moving forward, the merging of classical twentieth-century approaches with evolving omic tools should provide even deeper insights into host-symbiont interplay.
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Affiliation(s)
- Michael E Scharf
- Department of Entomology, Purdue University, West Lafayette, Indiana 47907, USA;
| | - Brittany F Peterson
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, Illinois 62026, USA;
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Telmadarrehei T, Tang JD, Raji O, Rezazadeh A, Narayanan L, Shmulsky R, Jeremic D. A Study of the Gut Bacterial Community of Reticulitermes virginicus Exposed to Chitosan Treatment. INSECTS 2020; 11:E681. [PMID: 33049915 PMCID: PMC7601259 DOI: 10.3390/insects11100681] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/28/2020] [Accepted: 10/05/2020] [Indexed: 01/04/2023]
Abstract
A thorough understanding of microbial communities in the gut of lower termites is needed to develop target-specific and environmentally benign wood protection systems. In this study, the bacterial community from Reticulitermes virginicus was examined by Illumina sequencing of 16S ribosomal RNA (rRNA) spanning the V3 and V4 regions. Prior to library preparation, the termites were subjected to five treatments over an 18-day period: three groups were fed on wood treated with 0.5% chitosan, 25% acetic acid, or water, the fourth group was taken directly from the original collection log, and the fifth group was starved. Metagenomic sequences were analyzed using QIIME 2 to understand the treatments' effects on the dynamics of the gut bacteria. Four dominant phyla were detected: Bacteroidetes (34.4% of reads), Firmicutes (20.6%), Elusimicrobia (15.7%), and Proteobacteria (12.9%). A significant effect of chitosan treatment was observed in two phyla; Firmicutes abundance was significantly lower with chitosan treatment when compared to other groups, while Actinobacteria was lower in unexposed and starved termites. The results suggest that chitosan treatment not only affects the structure of the microbial community in the gut, but other treatments such as starving also cause shifts in termite gut communities.
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Affiliation(s)
- Telmah Telmadarrehei
- Department of Sustainable Bioproducts, Mississippi State University, 201 Locksley Way, Starkville, MS 39759, USA; (O.R.); (L.N.); (R.S.); (D.J.)
| | - Juliet D. Tang
- Forest Products Laboratory, USDA Forest Service, 201 Lincoln Green, Starkville, MS 39759, USA;
| | - Olanrewaju Raji
- Department of Sustainable Bioproducts, Mississippi State University, 201 Locksley Way, Starkville, MS 39759, USA; (O.R.); (L.N.); (R.S.); (D.J.)
- Department of Chemical Engineering and Applied Science, University of Toronto, 200 College Street, Toronto, ON M5S 3E5, Canada
| | - Amir Rezazadeh
- Institute of Food and Agriculture Science, University of Florida, 8400 Picos Road, Ste. 101, Fort Pierce, FL 34945, USA;
| | - Lakshmi Narayanan
- Department of Sustainable Bioproducts, Mississippi State University, 201 Locksley Way, Starkville, MS 39759, USA; (O.R.); (L.N.); (R.S.); (D.J.)
| | - Rubin Shmulsky
- Department of Sustainable Bioproducts, Mississippi State University, 201 Locksley Way, Starkville, MS 39759, USA; (O.R.); (L.N.); (R.S.); (D.J.)
| | - Dragica Jeremic
- Department of Sustainable Bioproducts, Mississippi State University, 201 Locksley Way, Starkville, MS 39759, USA; (O.R.); (L.N.); (R.S.); (D.J.)
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16
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Blanton AG, Peterson BF. Symbiont-Mediated Insecticide Detoxification as an Emerging Problem in Insect Pests. Front Microbiol 2020; 11:547108. [PMID: 33101225 PMCID: PMC7554331 DOI: 10.3389/fmicb.2020.547108] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 09/09/2020] [Indexed: 01/01/2023] Open
Abstract
Pesticide use is prevalent with applications from the backyard gardener to large-scale agriculture and combatting pests in homes and industrial settings. Alongside the need to control unwanted pests comes the selective pressure generated by sustained pesticide use has become a concern leading to environmental contamination, pest resistance, and, thus, reduced pesticide efficacy. Despite efforts to improve the environmental impact and reduce off-target effects, chemical pesticides are relied on and control failures are costly. Though pesticide resistance mechanisms vary, one pattern that has recently emerged is symbiont-mediated detoxification within insect pests. The localization within the insect host, the identity of the symbiotic partner, and the stability of the associations across different systems vary. The diversity of insects and ecological settings linked to this phenomenon are broad. In this mini-review, we summarize the recent trend of insecticide detoxification modulated by symbiotic associations between bacteria and insects, as well as highlight the implications for pesticide development, pest management strategies, and pesticide bioremediation.
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Affiliation(s)
- Alison G Blanton
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL, United States
| | - Brittany F Peterson
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL, United States
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Stephens ME, Gage DJ. Single-cell amplicon sequencing reveals community structures and transmission trends of protist-associated bacteria in a termite host. PLoS One 2020; 15:e0233065. [PMID: 32413056 PMCID: PMC7228121 DOI: 10.1371/journal.pone.0233065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 04/27/2020] [Indexed: 01/04/2023] Open
Abstract
The hindgut protists of wood-feeding termites are usually colonized by prokaryotic symbionts. Many of the hurdles that have prevented a better understanding of these symbionts arise from variation among protist and termite host species and the inability to maintain prominent community members in culture. These issues have made it difficult to study the fidelity, acquisition, and differences in colonization of protists by bacterial symbionts. In this study, we use high throughput amplicon sequencing of the V4 region of 16S rRNA genes to determine the composition of bacterial communities associated with single protist cells of six protist species, from the genera Pyrsonympha, Dinenympha, and Trichonympha that are present in the hindgut of the termite Reticulitermes flavipes. By analyzing amplicon sequence variants (ASVs), the diversity and distribution of protist-associated bacteria was compared within and across these six different protist species. ASV analysis showed that, in general, each protist genus associated with a distinct community of bacterial symbionts which were conserved across different termite colonies. However, some ASVs corresponding to ectosymbionts (Spirochaetes) were shared between different Dinenympha species and to a lesser extent with Pyrsonympha and Trichonympha hosts. This suggested that certain bacterial symbionts may be cosmopolitan to some degree and perhaps acquired by horizontal transmission. Using a fluorescence-based cell assay, we could observe the horizontal acquisition of surface-bound bacteria. This acquisition was shown to be time-dependent, involve active processes, and was non-random with respect to binding locations on some protists.
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Affiliation(s)
- Michael E. Stephens
- Department of Entomology, Cornell University, Ithaca NY, United States of America
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States of America
| | - Daniel J. Gage
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States of America
- * E-mail:
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Guo Y, Lin Q, Chen L, Carballar-Lejarazú R, Zhang A, Shao E, Liang G, Hu X, Wang R, Xu L, Zhang F, Wu S. Characterization of bacterial communities associated with the pinewood nematode insect vector Monochamus alternatus Hope and the host tree Pinus massoniana. BMC Genomics 2020; 21:337. [PMID: 32357836 PMCID: PMC7195709 DOI: 10.1186/s12864-020-6718-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 04/05/2020] [Indexed: 01/24/2023] Open
Abstract
Background Monochamus alternatus Hope is one of the insect vectors of pinewood nematode (Bursaphelenchus xylophilus), which causes the destructive pine wilt disease. The microorganisms within the ecosystem, comprising plants, their environment, and insect vectors, form complex networks. This study presents a systematic analysis of the bacterial microbiota in the M. alternatus midgut and its habitat niche. Methods Total DNA was extracted from 20 types of samples (with three replicates each) from M. alternatus and various tissues of healthy and infected P. massoniana (pines). 16S rDNA amplicon sequencing was conducted to determine the composition and diversity of the bacterial microbiota in each sample. Moreover, the relative abundances of bacteria in the midgut of M. alternatus larvae were verified by counting the colony-forming units. Results Pinewood nematode infection increased the microbial diversity in pines. Bradyrhizobium, Burkholderia, Dyella, Mycobacterium, and Mucilaginibacter were the dominant bacterial genera in the soil and infected pines. These results indicate that the bacterial community in infected pines may be associated with the soil microbiota. Interestingly, the abundance of the genus Gryllotalpicola was highest in the bark of infected pines. The genus Cellulomonas was not found in the midgut of M. alternatus, but it peaked in the phloem of infected pines, followed by the phloem of heathy pines. Moreover, the genus Serratia was not only present in the habitat niche, but it was also enriched in the M. alternatus midgut. The colony-forming unit assays showed that the relative abundance of Serratia sp. peaked in the midgut of instar II larvae (81%). Conclusions Overall, the results indicate that the bacterial microbiota in the soil and in infected pines are correlated. The Gryllotalpicola sp. and Cellulomonas sp. are potential microbial markers of pine wilt disease. Additionally, Serratia sp. could be an ideal agent for expressing insecticidal protein in the insect midgut by genetic engineering, which represents a new use of microbes to control M. alternatus.
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Affiliation(s)
- Yajie Guo
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, 350000, China.,Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, 350000, China.,State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, 350000, China
| | - Qiannan Lin
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, 350000, China.,Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, 350000, China
| | - Lyuyi Chen
- Universityof California, Irvine, CA, 92697-4025, USA
| | - Rebeca Carballar-Lejarazú
- Department of Microbiology & Molecular Genetics, University of California, Irvine, CA, 92697-4025, USA
| | - Aishan Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, 350000, China
| | - Ensi Shao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, 350000, China
| | - Guanghong Liang
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, 350000, China.,Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, 350000, China
| | - Xia Hu
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, 350000, China.,Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, 350000, China
| | - Rong Wang
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, 350000, China.,Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, 350000, China
| | - Lei Xu
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Feiping Zhang
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, 350000, China. .,Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, 350000, China.
| | - Songqing Wu
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, 350000, China. .,Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou, 350000, China. .,State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, 350000, China.
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19
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Waidele L, Korb J, Voolstra CR, Dedeine F, Staubach F. Ecological specificity of the metagenome in a set of lower termite species supports contribution of the microbiome to adaptation of the host. Anim Microbiome 2019; 1:13. [PMID: 33499940 PMCID: PMC7807685 DOI: 10.1186/s42523-019-0014-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 09/23/2019] [Indexed: 12/27/2022] Open
Abstract
Background Elucidating the interplay between hosts and their microbiomes in ecological adaptation has become a central theme in evolutionary biology. A textbook example of microbiome-mediated adaptation is the adaptation of lower termites to a wood-based diet, as they depend on their gut microbiome to digest wood. Lower termites have further adapted to different life types. Termites of the wood-dwelling life type never leave their nests and feed on a uniform diet. Termites of the foraging life type forage for food outside the nest and have access to other nutrients. Here we sought to investigate whether the microbiome that is involved in food substrate breakdown and nutrient acquisition might contribute to adaptation to these dietary differences. We reasoned that this should leave ecological imprints on the microbiome. Results We investigated the protist and bacterial microbiomes of a total of 29 replicate colonies from five termite species, covering both life types, using metagenomic shotgun sequencing. The microbiome of wood-dwelling species with a uniform wood diet was enriched for genes involved in lignocellulose degradation. Furthermore, metagenomic patterns suggest that the microbiome of wood-dwelling species relied primarily on direct fixation of atmospheric nitrogen, while the microbiome of foraging species entailed the necessary pathways to utilize nitrogen in the form of nitrate for example from soil. Conclusion Our findings are consistent with the notion that the microbiome of wood-dwelling species bears an imprint of its specialization on degrading a uniform wood diet, while the microbiome of the foraging species might reflect its adaption to access growth limiting nutrients from more diverse sources. This supports the idea that specific subsets of functions encoded by the microbiome can contribute to host adaptation.
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Affiliation(s)
- Lena Waidele
- Biologie I, University of Freiburg, Hauptstr. 1, 79104, Freiburg, Germany
| | - Judith Korb
- Biologie I, University of Freiburg, Hauptstr. 1, 79104, Freiburg, Germany
| | | | - Franck Dedeine
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS - Université de Tours, 37200, Tours, France
| | - Fabian Staubach
- Biologie I, University of Freiburg, Hauptstr. 1, 79104, Freiburg, Germany.
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20
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Bai Z, Liu L, Noman MS, Zeng L, Luo M, Li Z. The influence of antibiotics on gut bacteria diversity associated with laboratory-reared Bactrocera dorsalis. BULLETIN OF ENTOMOLOGICAL RESEARCH 2019; 109:500-509. [PMID: 30394234 DOI: 10.1017/s0007485318000834] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The oriental fruit fly Bactrocera dorsalis (Hendel) is a destructive insect pest of a wide range of fruit crops. Commensal bacteria play a very important part in the development, reproduction, and fitness of their host fruit fly. Uncovering the function of gut bacteria has become a worldwide quest. Using antibiotics to remove gut bacteria is a common method to investigate gut bacteria function. In the present study, three types of antibiotics (tetracycline, ampicillin, and streptomycin), each with four different concentrations, were used to test their effect on the gut bacteria diversity of laboratory-reared B. dorsalis. Combined antibiotics can change bacteria diversity, including cultivable and uncultivable bacteria, for both male and female adult flies. Secondary bacteria became the dominant population in female and male adult flies with the decrease in normally predominant bacteria. However, in larvae, only the predominant bacteria decreased, the bacteria diversity did not change a lot, likely because of the short acting time of the antibiotics. The bacteria diversity did not differ among fruit fly treatments with antibiotics of different concentrations. This study showed the dynamic changes of gut bacterial diversity in antibiotics-treated flies, and provides a foundation for research on the function of gut bacteria of the oriental fruit fly.
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Affiliation(s)
- Z Bai
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - L Liu
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - M S Noman
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - L Zeng
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - M Luo
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Z Li
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China
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Grieco MB, Lopes FAC, Oliveira LS, Tschoeke DA, Popov CC, Thompson CC, Gonçalves LC, Constantino R, Martins OB, Kruger RH, de Souza W, Thompson FL. Metagenomic Analysis of the Whole Gut Microbiota in Brazilian Termitidae Termites Cornitermes cumulans, Cyrilliotermes strictinasus, Syntermes dirus, Nasutitermes jaraguae, Nasutitermes aquilinus, Grigiotermes bequaerti, and Orthognathotermes mirim. Curr Microbiol 2019; 76:687-697. [DOI: 10.1007/s00284-019-01662-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 01/22/2019] [Indexed: 01/04/2023]
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22
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Luo C, Li Y, Chen Y, Fu C, Long W, Xiao X, Liao H, Yang Y. Bamboo lignocellulose degradation by gut symbiotic microbiota of the bamboo snout beetle Cyrtotrachelus buqueti. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:70. [PMID: 30976320 PMCID: PMC6442426 DOI: 10.1186/s13068-019-1411-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 03/15/2019] [Indexed: 05/23/2023]
Abstract
BACKGROUND Gut symbiotic microbiota plays a critical role in nutrient supply, digestion, and absorption. The bamboo snout beetle, Cyrtotrachelus buqueti, a common pest of several bamboo species, exhibits high lignocellulolytic enzyme activity and contains various CAZyme genes. However, to date, no studies have evaluated the role of gut symbiotic microbiota of the snout beetle on bamboo lignocellulose degradation. Therefore, the present study investigated the role of gut symbiotic microbiota of C. buqueti on bamboo lignocellulose degradation. RESULTS Gut symbiotic microbiota of female (CCJ), male (XCJ), and larvae (YCJ) beetles was used to treat bamboo shoot particles (BSPs) in vitro for 6 days. Scanning electron microscopy (SEM) revealed significant destruction of the lignocellulose structure after treatment, which was consistent with the degradation efficiencies of CCJ, XCJ, and YCJ for cellulose (21.11%, 17.58% and 18.74%, respectively); hemicellulose (22.22%, 27.18% and 34.20%, respectively); and lignin (19.83%, 24.30% and 32.97%, respectively). Gut symbiotic microbiota of adult and larvae beetles was then identified using 16sRNA sequencing, which revealed that four microbes: Lactococcus, Serratia, Dysgonomonas and Enterococcus, comprise approximately 84% to 94% of the microbiota. Moreover, the genomes of 45 Lactococcus, 72 Serratia, 86 Enterococcus and 4 Dysgonomonas microbes were used to analyse resident CAZyme genes. These results indicated that gut symbiotic microbiota of adult and larvae C. buqueti is involved in the lignocellulose degradation traits shown by the host. CONCLUSIONS This study shows that the gut symbiotic microbiota of C. buqueti participates in bamboo lignocellulose degradation, providing innovative findings for bamboo lignocellulose bioconversion. Furthermore, the results of this study will allow us to further isolate lignocellulose-degrading microbiota for use in bamboo lignocellulose bioconversion.
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Affiliation(s)
- Chaobing Luo
- Bamboo Diseases and Pests Control and Resources Development Key Laboratory of Sichuan Province, Leshan Normal University, No. 778, Riverside Road, Central District, Leshan, 614000 Sichuan China
| | - Yuanqiu Li
- Bamboo Diseases and Pests Control and Resources Development Key Laboratory of Sichuan Province, Leshan Normal University, No. 778, Riverside Road, Central District, Leshan, 614000 Sichuan China
- College of Food and Biological Engineering, Xihua University, Chengdu, 610039 Sichuan China
| | - Ying Chen
- Bamboo Diseases and Pests Control and Resources Development Key Laboratory of Sichuan Province, Leshan Normal University, No. 778, Riverside Road, Central District, Leshan, 614000 Sichuan China
- College of Food and Biological Engineering, Xihua University, Chengdu, 610039 Sichuan China
| | - Chun Fu
- Bamboo Diseases and Pests Control and Resources Development Key Laboratory of Sichuan Province, Leshan Normal University, No. 778, Riverside Road, Central District, Leshan, 614000 Sichuan China
| | - Wencong Long
- Bamboo Diseases and Pests Control and Resources Development Key Laboratory of Sichuan Province, Leshan Normal University, No. 778, Riverside Road, Central District, Leshan, 614000 Sichuan China
| | - Ximeng Xiao
- Bamboo Diseases and Pests Control and Resources Development Key Laboratory of Sichuan Province, Leshan Normal University, No. 778, Riverside Road, Central District, Leshan, 614000 Sichuan China
- College of Food and Biological Engineering, Xihua University, Chengdu, 610039 Sichuan China
| | - Hong Liao
- Bamboo Diseases and Pests Control and Resources Development Key Laboratory of Sichuan Province, Leshan Normal University, No. 778, Riverside Road, Central District, Leshan, 614000 Sichuan China
| | - Yaojun Yang
- Bamboo Diseases and Pests Control and Resources Development Key Laboratory of Sichuan Province, Leshan Normal University, No. 778, Riverside Road, Central District, Leshan, 614000 Sichuan China
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Gut microbiota dynamics and functionality in Reticulitermes grassei after a 7-day dietary shift and ciprofloxacin treatment. PLoS One 2018; 13:e0209789. [PMID: 30590374 PMCID: PMC6307977 DOI: 10.1371/journal.pone.0209789] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 12/11/2018] [Indexed: 12/27/2022] Open
Abstract
Gut microbial structure in animals depends on the host, dietary habits and local environment. A random event, dietary change or antibiotic treatment may alter the gut environment with possible repercussions for the bacterial community composition and functionality and ultimately host fitness. The present study was focused on the composition, structure and functionality of gut microbiota in Reticulitermes grassei and the data obtained was compared with sequence surveys of three other Reticulitermes species. Each Reticulitermes species had a significantly different bacterial gut microbiota (pairwise significance tests using the Kolmogorov-Smirnov test), but a similar pattern of distribution (P-test in weighted Unifrac). The core gut microbiota from the analyzed Reticulitermes species contained 16 bacterial operational taxonomic units. Enzymes (KO) were detected from 14 pathways related to carbohydrate metabolism. R. grassei and R. hesperus, based on relative abundance of KO, had the most similar carbohydrate pathway patterns. In addition, we described the gut microbiota and functionality pathways in R. grassei after a 7-day dietary shift and antibiotic (ciprofloxacin) treatment. Both factors, but above all the antibiotic, altered the relative abundance of certain microbial groups, although the changes were not statistically significant (P-test in weighted Unifrac). The cellulose diet enhanced the carbohydrate pathways related to propanoate, butanoate, ascorbate, and glyoxylate metabolism. The antibiotic treatment affected galactose metabolism, the citrate cycle and inositol phosphate metabolism. Those functional changes may be related to changes in the abundance of several bacterial groups. Our findings provide insights into the stability of the gut microbiota in R. grassei and a resilience response to dietary shift or antibiotic treatment disturbance after 7 days.
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Duarte S, Nobre T, Borges PAV, Nunes L. Symbiotic flagellate protists as cryptic drivers of adaptation and invasiveness of the subterranean termite Reticulitermes grassei Clément. Ecol Evol 2018; 8:5242-5253. [PMID: 29938049 PMCID: PMC6010709 DOI: 10.1002/ece3.3819] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 11/21/2017] [Accepted: 12/06/2017] [Indexed: 12/18/2022] Open
Abstract
Changes in flagellate protist communities of subterranean termite Reticulitermes grassei across different locations were evaluated following four predictions: (i) Rural endemic (Portugal mainland) termite populations will exhibit high diversity of symbionts; (ii) invasive urban populations (Horta city, Faial island, Azores), on the contrary, will exhibit lower diversity of symbionts, showing high similarity of symbiont assemblages through environmental filtering; (iii) recent historical colonization of isolated regions-as the case of islands-will imply a loss of symbiont diversity; and (iv) island isolation will trigger a change in colony breeding structure toward a less aggressive behavior. Symbiont flagellate protist communities were morphologically identified, and species richness and relative abundances, as well as biodiversity indices, were used to compare symbiotic communities in colonies from urban and rural environments and between island invasive and mainland endemic populations. To evaluate prediction on the impact of isolation (iv), aggression tests were performed among termites comprising island invasive and mainland endemic populations. A core group of flagellates and secondary facultative symbionts was identified. Termites from rural environments showed, in the majority of observed colonies, more diverse and abundant protist communities, probably confirming prediction (i). Corroborating prediction (ii), the two least diverse communities belong to termites captured inside urban areas. The Azorean invasive termite colonies had more diverse protist communities than expected and prediction (iii) which was not verified within this study. Termites from mainland populations showed a high level of aggressiveness between neighboring colonies, in contrast to the invasive colonies from Horta city, which were not aggressive to neighbors according to prediction (iv). The symbiotic flagellate community of R. grassei showed the ability to change in a way that might be consistent with adaptation to available conditions, possibly contributing to optimization of the colonization of new habitats and spreading of its distribution area, highlighting R. grassei potential as an invasive species.
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Affiliation(s)
- Sónia Duarte
- Structures DepartmentLNECLisbonPortugal
- Faculty of Agrarian and Environmental SciencescE3c – Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity GroupUniversity of the AzoresAzoresPortugal
| | - Tânia Nobre
- Laboratory of EntomologyICAAM ‐ Instituto de Ciências Agrárias e Ambientais MediterrânicasUniversity of ÉvoraÉvoraPortugal
| | - Paulo A. V. Borges
- Faculty of Agrarian and Environmental SciencescE3c – Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity GroupUniversity of the AzoresAzoresPortugal
| | - Lina Nunes
- Structures DepartmentLNECLisbonPortugal
- Faculty of Agrarian and Environmental SciencescE3c – Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity GroupUniversity of the AzoresAzoresPortugal
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Zhou J, Duan J, Gao M, Wang Y, Wang X, Zhao K. Diversity, Roles, and Biotechnological Applications of Symbiotic Microorganisms in the Gut of Termite. Curr Microbiol 2018; 76:755-761. [PMID: 29754180 DOI: 10.1007/s00284-018-1502-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 04/25/2018] [Indexed: 12/20/2022]
Abstract
Termites are global pests and can cause serious damage to buildings, crops, and plantation forests. The symbiotic intestinal flora plays an important role in the digestion of cellulose and nitrogen in the life of termites. Termites and their symbiotic microbes in the gut form a synergistic system. These organism work together to digest lignocellulose to make the termites grow on nitrogen deficient food. In this paper, the diversity of symbiotic microorganisms in the gut of termites, including protozoan, spirochetes, actinomycetes, fungus and bacteria, and their role in the digestion of lignocellulose and also the biotechnological applications of these symbiotic microorganisms are discussed. The high efficiency lignocellulose degradation systems of symbiotic microbes in termite gut not only provided a new way of biological energy development, but also has immense prospect in the application of cellulase enzymes. In addition, the study on the symbiotic microorganisms in the gut of termites will also provide a new method for the biological control of termites by the endophytic bacteria in the gut of termites.
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Affiliation(s)
- Jing Zhou
- Key Laboratory of Microbiology, School of Life Science, Heilongjiang University, Harbin, 150080, China
| | - Jiwei Duan
- Key Laboratory of Microbiology, School of Life Science, Heilongjiang University, Harbin, 150080, China
| | - Mingkun Gao
- College of Animal Science and Technology, Northeast Agriculture University, Harbin, 150030, China
| | - Ying Wang
- Key Laboratory of Microbiology, School of Life Science, Heilongjiang University, Harbin, 150080, China
| | - Xiaohua Wang
- Key Laboratory of Microbiology, School of Life Science, Heilongjiang University, Harbin, 150080, China. .,Heilongjiang University Library, Heilongjiang University, Harbin, 150080, China.
| | - Kai Zhao
- Key Laboratory of Microbiology, School of Life Science, Heilongjiang University, Harbin, 150080, China.
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Peterson BF, Scharf ME. Metatranscriptomic Techniques for Identifying Cellulases in Termites and their Symbionts. Methods Mol Biol 2018; 1796:85-101. [PMID: 29856048 DOI: 10.1007/978-1-4939-7877-9_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Characterizing symbiotic communities, like that of the termite hindgut, is essential for understanding their functionality and capabilities. However, the same complexity that allows termites to digest wood so efficiently also makes them difficult to study. With the expansion in technology and sequencing strategies the feasibility of sequencing entire consortiums or microecosystems is now possible. Here we present an adapted library preparation strategy which allows for the detection and measurement of expressed genes from all three domains of life in a single sample simultaneously. This technique effectively captures the transcriptome contributions by the various members of the consortium regardless of their taxonomic identity, which can then be annotated using custom-built databases and reciprocal BLASTing. Joining the universality of this library prep strategy with the power of bioinformatics allows for the identification of cellulases and other genes encoding carbohydrate active enzymes from complex communities using metatranscriptomics.
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Peterson BF, Scharf ME. Metatranscriptome analysis reveals bacterial symbiont contributions to lower termite physiology and potential immune functions. BMC Genomics 2016; 17:772. [PMID: 27716053 PMCID: PMC5045658 DOI: 10.1186/s12864-016-3126-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 09/26/2016] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Symbioses throughout the animal kingdom are known to extend physiological and ecological capabilities to hosts. Insect-microbe associations are extremely common and are often related to novel niche exploitation, fitness advantages, and even speciation events. These phenomena include expansions in host diet, detoxification of insecticides and toxins, and increased defense against pathogens. However, dissecting the contributions of individual groups of symbionts at the molecular level is often underexplored due to methodological and analytical limitations. Termites are one of the best studied systems for physiological collaborations between host and symbiota; however, most work in lower termites (those with bacterial and protist symbionts) focuses on the eukaryotic members of this symbiotic consortium. Here we present a metatranscriptomic analysis which provides novel insights into bacterial contributions to the holobiont of the eastern subterranean termite, Reticulitermes flavipes, in the presence and absence of a fungal pathogen. RESULTS Using a customized ribodepletion strategy, a metatranscriptome assembly was obtained representing the host termite as well as bacterial and protist symbiota. Sequence data provide new insights into biosynthesis, catabolism, and transport of major organic molecules and ions by the gut consortium, and corroborate previous findings suggesting that bacteria play direct roles in nitrogen fixation, amino acid biosynthesis, and lignocellulose digestion. With regard to fungal pathogen challenge, a total of 563 differentially expressed candidate host and symbiont contigs were identified (162 up- and 401 downregulated; α/FDR = 0.05) including an upregulated bacterial amidohydrolase. CONCLUSIONS This study presents the most complete bacterial metatranscriptome from a lower termite and provides a framework on which to build a more complete model of termite-symbiont interactions including, but not limited to, digestion and pathogen defense.
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Affiliation(s)
- Brittany F Peterson
- Department of Entomology, Purdue University, 901 W. State St, West Lafayette, IN, 47907-2089, USA. .,Present address: Center for Insect Science, University of Arizona, 1007 E. Lowell St, Tucson, AZ, 85721, USA.
| | - Michael E Scharf
- Department of Entomology, Purdue University, 901 W. State St, West Lafayette, IN, 47907-2089, USA
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Bouchon D, Zimmer M, Dittmer J. The Terrestrial Isopod Microbiome: An All-in-One Toolbox for Animal-Microbe Interactions of Ecological Relevance. Front Microbiol 2016; 7:1472. [PMID: 27721806 PMCID: PMC5033963 DOI: 10.3389/fmicb.2016.01472] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 09/05/2016] [Indexed: 12/12/2022] Open
Abstract
Bacterial symbionts represent essential drivers of arthropod ecology and evolution, influencing host traits such as nutrition, reproduction, immunity, and speciation. However, the majority of work on arthropod microbiota has been conducted in insects and more studies in non-model species across different ecological niches will be needed to complete our understanding of host–microbiota interactions. In this review, we present terrestrial isopod crustaceans as an emerging model organism to investigate symbiotic associations with potential relevance to ecosystem functioning. Terrestrial isopods comprise a group of crustaceans that have evolved a terrestrial lifestyle and represent keystone species in terrestrial ecosystems, contributing to the decomposition of organic matter and regulating the microbial food web. Since their nutrition is based on plant detritus, it has long been suspected that bacterial symbionts located in the digestive tissues might play an important role in host nutrition via the provisioning of digestive enzymes, thereby enabling the utilization of recalcitrant food compounds (e.g., cellulose or lignins). If this were the case, then (i) the acquisition of these bacteria might have been an important evolutionary prerequisite for the colonization of land by isopods, and (ii) these bacterial symbionts would directly mediate the role of their hosts in ecosystem functioning. Several bacterial symbionts have indeed been discovered in the midgut caeca of terrestrial isopods and some of them might be specific to this group of animals (i.e., Candidatus Hepatoplasma crinochetorum, Candidatus Hepatincola porcellionum, and Rhabdochlamydia porcellionis), while others are well-known intracellular pathogens (Rickettsiella spp.) or reproductive parasites (Wolbachia sp.). Moreover, a recent investigation of the microbiota in Armadillidium vulgare has revealed that this species harbors a highly diverse bacterial community which varies between host populations, suggesting an important share of environmental microbes in the host-associated microbiota. In this review, we synthesize our current knowledge on the terrestrial isopod microbiome and identify future directions to (i) fully understand the functional roles of particular bacteria (both intracellular or intestinal symbionts and environmental gut passengers), and (ii) whether and how the host-associated microbiota could influence the performance of terrestrial isopods as keystone species in soil ecosystems.
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Affiliation(s)
- Didier Bouchon
- UMR CNRS 7267, Ecologie et Biologie des Interactions, Université de Poitiers Poitiers, France
| | - Martin Zimmer
- Leibniz Center for Tropical Marine Ecology Bremen, Germany
| | - Jessica Dittmer
- Rowland Institute at Harvard, Harvard University, Cambridge MA, USA
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Peterson BF, Scharf ME. Lower Termite Associations with Microbes: Synergy, Protection, and Interplay. Front Microbiol 2016; 7:422. [PMID: 27092110 PMCID: PMC4824777 DOI: 10.3389/fmicb.2016.00422] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/16/2016] [Indexed: 11/15/2022] Open
Abstract
Lower-termites are one of the best studied symbiotic systems in insects. Their ability to feed on a nitrogen-poor, wood-based diet with help from symbiotic microbes has been under investigation for almost a century. A unique microbial consortium living in the guts of lower termites is essential for wood-feeding. Host and symbiont cellulolytic enzymes synergize each other in the termite gut to increase digestive efficiency. Because of their critical role in digestion, gut microbiota are driving forces in all aspects of termite biology. Social living also comes with risks for termites. The combination of group living and a microbe-rich habitat makes termites potentially vulnerable to pathogenic infections. However, the use of entomopathogens for termite control has been largely unsuccessful. One mechanism for this failure may be symbiotic collaboration; i.e., one of the very reasons termites have thrived in the first place. Symbiont contributions are thought to neutralize fungal spores as they pass through the termite gut. Also, when the symbiont community is disrupted pathogen susceptibility increases. These recent discoveries have shed light on novel interactions for symbiotic microbes both within the termite host and with pathogenic invaders. Lower termite biology is therefore tightly linked to symbiotic associations and their resulting physiological collaborations.
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Affiliation(s)
| | - Michael E Scharf
- Department of Entomology, Purdue University, West Lafayette IN, USA
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Sethi A, Karl ZJ, Scharf ME. Digestion of Termiticide Bait Matrices by the Pest Termite Reticulitermes flavipes (Isoptera: Rhinotermitidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2016; 109:982-986. [PMID: 26896534 DOI: 10.1093/jee/tow017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Termites are highly effective digesters of wood lignocellulose, which is a central factor contributing to their global status as pests of wooden structures. For the same reason, termite baits that combine cellulosic matrices with slow-acting insecticides are both effective and popular as a reduced-risk approach for termite control. This study took a novel approach for assessing digestibility of termite bait matrices and matrix components to gain potentially new insights into bait attractiveness and efficacy. The rationale behind this study is that termite baits that are more digestible should have more nutritional value to termites and thus encourage maximal feeding and trophallactic transfer of active ingredients through termite colonies. Studies were done using in vitro digestion assays with termite gut protein extracts followed by colorimetric detection of released glucose and pentose monosaccharides from test substrates. The substrates tested included two commercial bait matrices (Recruit IV and Recruit II HD), two matrix components (compressed and toasted compressed cellulose), and two natural pine woods as positive controls (southern yellow and northern pine). Overall results show equal or greater monosaccharide availability for some commercial matrices than standard pine lignocelluloses, suggesting sufficient nutritional value for the proprietary matrices. Another more prominent trend was significant intercolony variation in digestibility across substrates, possibly resulting from differences in microbiota composition, long-term diet adaptation, or both. These findings thus illuminate new nutrition-based factors that can potentially impact bait feeding, trophallactic exchange, and efficacy.
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