Cellulolytic Microbiomes

BACKGROUND: Ruminal microbial communities enriched on lignocellulosic biomass have shown considerable promise for the discovery of microorganisms and enzymes involved in digesting cell wall compounds, a key bottleneck in the development of second-generation biofuels and bioproducts, enabling a circular bioeconomy. Cardoon (Cynara cardunculus) is a promising inedible energy crop for current and future cellulosic biorefineries and the emerging bioenergy and bioproducts industries. The rumen microbiome can be considered an anaerobic "bioreactor", where the resident microbiota carry out the depolymerization and hydrolysis of plant cell wall polysaccharides (PCWPs) through the catalytic action of fibrolytic enzymes...

This study investigates A. mellifera gut microbiota diversity and enzymatic activities, aiming to utilize identified isolates for practical applications in sustainable crop residue management and soil health enhancement. This study sampled honey bees, analyzed gut bacterial diversity via 16S rRNA gene, and screened isolates for cellulolytic, hemicellulolytic, and pectinolytic activities, with subsequent assessment of enzymatic potential. The study reveals that cellulolytic and hemicellulolytic bacterial isolates, mainly from γ-Proteobacteria, Actinobacteria, and Firmicutes, have significant potential for crop residue management...

Coconut rhinoceros beetle (CRB, Oryctes rhinoceros) is an invasive palm pest whose larvae eat wood, yet lack the necessary digestive enzymes. This study confirmed endogenous CRB cellulase is inactive, suggesting microbial fermentation. The inner lining of the CRB hindgut has tree-like structures covered with a conspicuous biofilm. To identify possible symbionts, 16 S rRNA amplicon sequencing was used on individuals from across Taiwan. Several taxa of Clostridia, an anaerobic class including many cellulolytic bacteria, were highly abundant in most individuals from all locations...

Producing caproic acid via carboxylate platform is an environmentally-friendly approach for treating lignocellulosic agricultural waste. However, its implementation is still challenged by low product yields and selectivity. A microbiome named cellulolytic acid-producing microbiome (DCB), proficient in producing cellulolytic acid, was successfully acquired and shows promise for producing high-level caproic acid. In this study, a bioaugmentation method utilizing Clostridium kluyveri is proposed to enhance caproic acid yield of DCB using rice straw...

Ruminants play a key role in the conversion of cellulolytic plant material into high-quality meat and milk protein for humans. The rumen microbiome is the driver of this conversion, yet there is little information on how gene expression within the microbiome impacts the efficiency of this conversion process. The current study investigates gene expression in the rumen microbiome of beef heifers and bison and how transplantation of ruminal contents from bison to heifers alters gene expression. Understanding interactions between the host and the rumen microbiome is the key to developing informed approaches to rumen programming that will enhance production efficiency in ruminants...

In this study, fermentation experiments were conducted under mesophilic, thermophilic, and hyperthermophilic conditions to investigate adaptation of microbial communities and its effect on extracellular enzyme activities toward degradation of cellulose, hemicellulose and proteins in dairy manure. Hyperthermophilic conditions transformed the microbiome structure and stimulated activity of extracellular proteolytic, cellulolytic, and hemicellulolytic enzymes. Specifically, the activities of protease, cellulose 1,4-β-cellobiosidase, and β-glucosidase secreted by hyperthermophilic microbes were higher by 22%, 47% and 49% compared to those produced by mesophilic and thermophilic communities...

Sampling of ruminant saliva has gained interest as a non-invasive proxy for exploring the structure of the rumen microbiome. However, the subsequent data analysis assumes that bacteria originating from the oral cavity are merely passengers in the rumen and play no active role. In this study, it was hypothesised that metabolically active oral bacteria present in the salivary microbiome play a role in the ruminal degradation of plant material. In vitro cultivation-based enumeration confirmed that the ruminant oral cavity harbours a significant number of anaerobic and cellulolytic bacteria that are metabolically active under ruminal conditions...

Improvement of nutrient utilization to promote growth performance is always pursued in poultry. In this study, a total of 360 1-day-old male ducklings were randomly assigned to 3 treatments in terms of diet treatment groups. Three treatments were as follows: basal diet (Con group) or basal diet supplemented with 300 mg/kg multi-enzymes (ENZ group) or 500 mg/kg lysophospholipids (LPL group). On d 42, ducks were slaughtered for samplings. The results revealed that supplementary LPL improved the body weight (BW) at d 14 and average daily gain (ADG) during d 1-14 and improved the feed conversion rate (FCR) for the overall period (P < 0...

Ruminants are responsible for enteric methane production contributing significantly to the anthropogenic greenhouse gases in the atmosphere. Moreover, dietary energy is lost as methane gas without being available for animal use. Therefore, many mitigation strategies aiming at interventions at animals, diet, and microbiota have been explored by researchers. Specific chemical analogues targeting the enzymes of the methanogenic pathway appear to be more effective in specifically inhibiting the growth of methane-producing archaea without hampering another microbiome, particularly, cellulolytic microbiota...

BACKGROUND: Artificial rearing system, commonly used in prolific sheep breeds, is associated to increased mortality and morbidity rates before weaning, which might be linked to perturbations in digestive tract maturation, including microbiota colonization. This study evaluated the effect of rearing mode (mothered or artificially reared) on the establishment of the rumen and intestinal microbiome of lambs from birth to weaning. We also measured immunological and zootechnical parameters to assess lambs' growth and health...

The Sembawang Hot Spring in Singapore lies at the foot of a major regional geological feature called the Bentong-Raub Suture Zone. Amid an extensively managed surface geothermal park, an undisturbed hot spring emerges with source water at 61°C, pH 6.8, and 1 mg/L dissolved sulfide. A small main pool at the source supported orange-green benthic flocs, whereas the outflow channel with gradually less extreme environmental stress supported extensive vivid green microbial mats. Microscopy revealed that cyanobacterial morphotypes were distinct in flocs and mats at several intervals along the environmental gradient, and we describe a spiraling pattern in the oscillatorian cyanobacteria that may reflect response to poly-extreme stress...

Fibrobacter succinogenes is a cellulolytic predominant bacterium that plays an essential role in the degradation of plant fibers in the rumen ecosystem. It converts cellulose polymers into intracellular glycogen and the fermentation metabolites succinate, acetate, and formate. We developed dynamic models of F. succinogenes S85 metabolism on glucose, cellobiose, and cellulose on the basis of a network reconstruction done with the Automatic Reconstruction of metabolic models (AuReMe) workspace. The reconstruction was based on genome annotation, 5 templates-based orthology methods, gap-filling and manual curation...

The process of straw decomposition is dynamic and is accompanied by the succession of the microbial decomposing community, which is driven by poorly understood interactions between microorganisms. Soil is a complex ecological niche, and the soil microbiome can serve as a source of potentially active cellulolytic microorganisms. Here, we performed an experiment on the de novo colonization of oat straw by the soil microbial community by placing nylon bags with sterilized oat straw in the pots filled with chernozem soil and incubating them for 6 months...

Biochanin A (BCA), an isoflavone phytoestrogen, is a secondary metabolite produced mainly in leguminous plants. The objective of this study was to evaluate the effect of BCA on lactation performance, nitrogen metabolism, and the health of dairy goat. Thirty mid-lactation Saanen dairy goats were divided into three groups randomly: control, 2 g/d BCA group, and 6 g/d BCA group. After 36 days of feeding, 30 dairy goats were transferred to individual metabolic cages. Subsequently, milk yield, feed intake, total feces, and urine excretion were recorded and samples were collected continuously for 3 days...

INTRODUCTION: A better understanding of the microbiota community in donkey foals during the weaning transition is a prerequisite to optimize gut function and improve feed efficiency. The objective of the present study was to investigate the dynamic changes in fecal microbiota in donkey foals from pre-to post-weaning period. METHODS: A total of 27 fecal samples of donkey foals were collected in the rectum before morning feeding at pre-weaning (30 days of age, PreW group, n  = 9), dur-weaning (100 days of age, DurW group, n  = 9) and post-weaning (170 days of age, PostW group, n  = 9) period...

The soil response to a jet-fuel contamination is uncertain. In this article, original data on the influence of a jet-fuel spillage on the topsoil properties are presented. The data set is obtained during a one-year long pot and field experiments with Dystric Arenosols, Fibric Histosols and Albic Luvisols. Kerosene loads were 1, 5, 10, 25 and 100 g/kg. The data set includes information about temporal changes in kerosene concentration; physicochemical properties, such as рН, moisture, cation exchange capacity, content of soil organic matter, available P and K, exchangeable NH4 + , and water-soluble NO3 - ; and biological properties, such as biological consumption of oxygen, and cellulolytic activity...

To support the overall health of horses, it is essential to maintain an optimal gut health (GH) status, which encompasses several physiological and functional aspects, including the balance and functionality of intestinal microbial populations and, accordingly, the effective digestion and absorption of nutrients. Numerous biotic and abiotic stressors can lead to an imbalance of GH, such as the quality of forages and the composition of diet, e.g., the inclusion of high energy-dense feeds to meet the energy requirements of performance horses...

INTRODUCTION: Negative energy balance (NEB) is the pathological basis of metabolic disorders in early lactation dairy cows. Rumen-protected glucose (RPG) is a feed additive to relieve NEB of cows in early lactation. The aims of the current study were to evaluate the impact of different doses of RPG supply on fecal microbiota and metabolome in early lactation dairy cows, and their correlation with each other. METHODS: A total of 24 multiparous Holstein dairy cows in early lactation were randomly assigned to one of four treatments for the first 35 days of the early lactation period, as follows: control group, a basal diet without RPG (CON); low RPG, a basal diet plus 200 g/d RPG (LRPG); medium RPG, a basal diet plus 350 g/d RPG (MRPG); or HRPG, high RPG, a basal diet plus 500 g/d RPG (HRPG)...

The effects of dietary supplementation with citrus flavonoid extract (CFE) on milk performance, rumen fermentation, rumen microbiome, rumen metabolome, and serum antioxidant indexes were evaluated. Eight multiparous lactating cows were allocated to a replicated 4 × 4 Latin square with 25-d periods consisting of 20 d of adaptation and 5 d of sampling. Experimental treatments included a control diet (CON) and CON supplemented with 50 g d-1 (CFE50), 100 g d-1 (CFE100), and 150 g d-1 (CFE150). Feeding CFE to dairy cows increased milk production and milk lactose...

The gut microbiome is essential for processing complex food compounds and synthesizing nutrients that the host cannot digest or produce, respectively. New model systems are needed to study how the metabolic capacity provided by the gut microbiome impacts the nutritional status of the host, and to explore possibilities for altering host metabolic capacity via the microbiome. Here, we colonized the nematode Caenorhabditis elegans gut with cellulolytic bacteria that enabled C. elegans to utilize cellulose, an otherwise indigestible substrate, as a carbon source...