Project description:Giant panda are carnivorous bears which feed almost exclusively on plant biomass (i.e. bamboo). The potential contribution of its gut microbiome to lignocellulose degradation has been mostly investigated with cultivation-independent approaches. Recently, we reported on the first lab-scale cultivation of giant panda gut microbiomes and described their actual fermentation capacity. Fermentation of bamboo leaf using green dung resulted in a neutral pH, the main products being ethanol, lactate and H2. Fermentation of bamboo pith using yellow dung resulted in an acidic pH, the main product being lactate. Here, we cultivated giant panda gut microbiomes to test 1) the impact of mixed dung as inoculum; 2) the fermentation capacity of solid lignocellulose as opposed to organics-rich biofluids in the dung; 3) the artificial shift of pH from neutral to acidic on bamboo leaf fermentation. Our results indicate that i) gut microbiomes fermentation of solid lignocellulose contributes up to a maximum of 1/3 even in the presence of organics-rich biofluids; ii) alcohols are an important product of bamboo leaf fermentation at neutral pH; iii) aside hemicellulose, gut microbiomes may degrade plant cell membranes to produce glycerol; iv) pH, rather than portion of bamboo, ultimately determines fermentation profiles and gut microbiome assemblage.
Project description:Single-cell RNA sequencing was performed on gut tissues of Cyrtotrachelus buqueti, including larval anterior midgut, larval posterior midgut, larval hindgut, and adult hindgut, to characterize intestinal cell-type composition and transcriptomic heterogeneity associated with bamboo digestion.
Project description:Insect gut microbiota plays important roles in acquiring nutrition, preventing pathogens infection, immune responses, and communicating with the environment. Gut microbiota can be affected by some external factors such as foods, temperature, and antibiotics. Spodoptera frugiperda (Lepidoptera: Noctuidae) is an important destructive pest of grain crops all over the world. The function of gut microbiota in S. frugiperda remains to be investigated. In this study, we fed the S. frugiperda with the antibiotic mixture (penicillin, gentamicin, rifampicin, and streptomycin) to perturb the gut microbiota, and further examined the effect of dysbiosis in gut microbiota on the gene expression of S. frugiperda by RNA sequencing. We found the composition and diversity of the gut bacterial community were changed in S. frugiperda after antibiotics treatmen, and the expression of genes related to energy and metabolic process were affected after antibiotics exposure in S. frugiperda. Our work will help understand the role of gut microbiota in insects.
Project description:The iconic giant panda is an endangered species known worldwide for its peculiar dietary habits. While retaining the digestive system of a carnivore, the giant panda successfully moved into a diet almost exclusively based on bamboo. Digestion of lignocellulose is believed to be conducted solely by its gut microbiome, provided that no lignocellulose-degrading enzyme was found in the giant panda’s genome. Many reports focused on which lignocellulose component feeds the giant panda, while little effort was made to link the products of bamboo fermentation to the panda’s dietary choices. In the present study, fermentation of either green leaves or yellow pith was conducted in the laboratory using gut microbiomes derived from either green or yellow stools, respectively. Green leaves were fermented to ethanol, lactate and acetate, while yellow pith to lactate resembling, respectively, hetero/homo-fermentation patterns. Several microbial pathways (assessed by metaproteomics) related to hemicellulose rather than cellulose degradation. However, alpha-amylases (E.C. 3.2.1.1) from the giant panda itself were the most predominant enzyme (up to 60% of all metaproteins), indicating that they have a primary role in bamboo digestion. The distinct fermentation profiles resulting from digestion of selected portions of bamboo may be part of the feeding strategy of giant pandas.
Project description:Bamboo represents the only major lineage of grasses that is native to forests and is one of the most important non-timber forest products in the world. Moso bamboo is a large woody bamboo that has ecological, economic and cultural value in Asia and accounts for ~70% of the total bamboo growth area (Peng et al., 2013). In the aspect of epigenetics of Moso bamboo,the total genomic DNA methylation rates in Moso bamboo at different chronological ages were significantly different (Yuan et al., 2014). Those show that the flowering of Moso bamboo are closely related to epigenetic modification. However, DNA methylation in single base resolution has never been reported in moso bamboo. In this study, leaves from three-week bamboo, one-year bamboo, flower in next year bamboo, flowering bamboo and Flower florets was used for bisulfite sequencing (BS-seq), and RNA-Seq. Genome-wide methylation profile and gene expression analysis were constructed to reveal the factors to regualte the phase transition from vegetative to reproductive growth in moso bamboo.
Project description:Bamboo represents the only major lineage of grasses that is native to forests and is one of the most important non-timber forest products in the world. Moso bamboo is a large woody bamboo that has ecological, economic and cultural value in Asia and accounts for ~70% of the total bamboo growth area (Peng et al., 2013). In the aspect of epigenetics of Moso bamboo,the total genomic DNA methylation rates in Moso bamboo at different chronological ages were significantly different (Yuan et al., 2014). Those show that the flowering of Moso bamboo are closely related to epigenetic modification. However, DNA methylation in single base resolution has never been reported in moso bamboo. In this study, leaves from three-week bamboo, one-year bamboo, flower in next year bamboo, flowering bamboo and Flower florets was used for bisulfite sequencing (BS-seq), and RNA-Seq. Genome-wide methylation profile and gene expression analysis were constructed to reveal the factors to regualte the phase transition from vegetative to reproductive growth in moso bamboo.
Project description:To explore the bacterial community profile of the gut of the African palm weevil and to identify the abundance and diversity of lignin degradation-associated bacteria in each gut segment.
Project description:<p>Bamboo rats (<em>Rhizomys pruinosus</em>) are among the few mammals that lives on a bamboo-based diet which is mainly composed of lignocellulose. However, the mechanisms of adaptation of their gut microbiome and metabolic systems in the degradation of lignocellulose are largely unknown. Here, we conducted a multi-omics analysis on bamboo rats to investigate the interaction between their gut microbiomes and metabolic systems in the pre- and post-weaning periods, and observed significant relationships between dietary types, gut microbiome, serum metabolome and host gene expression. For comparison, published gut microbial data from the famous bamboo-eating giant panda (<em>Ailuropoda melanoleuca</em>) were also used for analysis. We found that the adaptation of the gut microbiome of the bamboo rat to a lignocellulose diet is related to a member switch in the order Bacteroidales from family <em>Bacteroidaceae</em> to family <em>Muribaculaceae</em>, while for the famous bamboo-eating giant panda, several aerobes and facultative anaerobes increase after weaning. The conversion of bacteria with an increased relative abundance in bamboo rats after weaning enriched diverse carbohydrate-active enzymes (CAZymes) associated with lignocellulose degradation and functionally enhanced the biosynthesis of amino acids and B vitamins. Meanwhile, the circulating concentration of short chain fatty acids (SCFAs) derived metabolites and the metabolic capacity of linoleic acid in the host were significantly elevated. Our findings suggest that fatty acid metabolism, including linoleic acid and SCFAs, are the main energy sources for bamboo rats in response to the low-nutrient</p>
Project description:Genome scale metabolic model of Drosophila gut microbe Acetobacter fabarum
Abstract -
An important goal for many nutrition-based microbiome studies is to identify the metabolic function of microbes in complex microbial communities and their impact on host physiology. This research can be confounded by poorly understood effects of community composition and host diet on the metabolic traits of individual taxa. Here, we investigated these multiway interactions by constructing and analyzing metabolic models comprising every combination of five bacterial members of the Drosophila gut microbiome (from single taxa to the five-member community of Acetobacter and Lactobacillus species) under three nutrient regimes. We show that the metabolic function of Drosophila gut bacteria is dynamic, influenced by community composition, and responsive to dietary modulation. Furthermore, we show that ecological interactions such as competition and mutualism identified from the growth patterns of gut bacteria are underlain by a diversity of metabolic interactions, and show that the bacteria tend to compete for amino acids and B vitamins more frequently than for carbon sources. Our results reveal that, in addition to fermentation products such as acetate, intermediates of the tricarboxylic acid (TCA) cycle, including 2-oxoglutarate and succinate, are produced at high flux and cross-fed between bacterial taxa, suggesting important roles for TCA cycle intermediates in modulating Drosophila gut microbe interactions and the potential to influence host traits. These metabolic models provide specific predictions of the patterns of ecological and metabolic interactions among gut bacteria under different nutrient regimes, with potentially important consequences for overall community metabolic function and nutritional interactions with the host.IMPORTANCE Drosophila is an important model for microbiome research partly because of the low complexity of its mostly culturable gut microbiota. Our current understanding of how Drosophila interacts with its gut microbes and how these interactions influence host traits derives almost entirely from empirical studies that focus on individual microbial taxa or classes of metabolites. These studies have failed to capture fully the complexity of metabolic interactions that occur between host and microbe. To overcome this limitation, we reconstructed and analyzed 31 metabolic models for every combination of the five principal bacterial taxa in the gut microbiome of Drosophila This revealed that metabolic interactions between Drosophila gut bacterial taxa are highly dynamic and influenced by cooccurring bacteria and nutrient availability. Our results generate testable hypotheses about among-microbe ecological interactions in the Drosophila gut and the diversity of metabolites available to influence host traits.