Search Results (137)

Cellulose, the most abundant organic polymer in soil, is degraded by the action of microbial communities. Cellulolytic taxa are widespread in soils, enhancing the biodegradation of cellulose by the synergistic action of different cellulase enzymes. β-glucosidases are the last enzymes responsible for the degradation of cellulose by producing glucose from the conversion of the disaccharide cellobiose. Different soils from the states of Delaware, Maryland, New Jersey, and New York were analyzed by direct DNA extraction, PCR analysis, and next generation sequencing of amplicon sequences coding for β-glucosidase genes. To determine the community structure and diversity of microorganisms carrying β-glucosidase genes, amplicon sequence variant analysis was performed. Results showed that the majority of β-glucosidase genes did not match any known phylum or genera with an average of 84% of sequences identified as unclassified. The forest soil sample from New York showed the highest value with 95.62%. When identification was possible, the bacterial phyla Pseudomonadota, Actinomycetota, and Chloroflexota were found to be dominant microorganisms with β-glucosidase genes in soils. The Delaware soil showed the highest diversity with phyla and genera showing the presence of β-glucosidase gene sequences in bacteria, fungi, and plants. However, the Chloroflexota genus Kallotanue was detected in 3 out of the 4 soil locations. When phylogenetic analysis of unclassified β-glucosidase genes was completed, most sequences aligned with the Chloroflexota genus Kallotenue and the Pseudomonadota species Sphingomonas paucimobilis. Since most sequences did not match known phyla, there is tremendous potential to discover new enzymes for possible biotechnological and pharmaceutical applications. Full article

A novel cellulose-degrading bacterial strain, D3-1, capable of degrading cellulose under medium- to high-temperature conditions, was isolated from soil samples and identified as Staphylococcus caprae through 16SrRNA gene sequencing. The strain’s cellulase production was optimized by controlling different factors, such as pH, temperature, incubation period, substrate concentration, nitrogen and carbon sources, and response surface methods. The results indicated that the optimal conditions for maximum cellulase activity were an incubation time of 91.7 h, a temperature of 41.8 °C, and a pH of 4.9, which resulted in a maximum cellulase activity of 16.67 U/mL, representing a 165% increase compared to pre-optimization levels. The above experiment showed that, when maize straw flour was utilized as a natural carbon source, strain D3-1 exhibited relatively high cellulase production. Furthermore, gas chromatography–mass spectrometry (GC-MS) analysis of products in the degradation liquid revealed the presence of primary sugars. The results indicated that, in the denitrification of simulated sewage, supplying maize straw flour degradation liquid (MSFDL) as the carbon source resulted in a carbon/nitrogen (C/N) ratio of 6:1 after a 24 h reaction with the denitrifying strain WH-01. The total nitrogen (TN) reduction was approximately 70 mg/L, which is equivalent to the removal efficiency observed in the glucose-fed denitrification process. Meanwhile, during a 4 h denitrification reaction in urban sewage without any denitrifying bacteria, but with MSFDL supplied as the carbon source, the TN removal efficiency reached 11 mg/L, which is approximately 70% of the efficiency of the glucose-fed denitrification process. Furthermore, experimental results revealed that strain D3-1 exhibits some capacity for nitrogen removal; when the cellulose-degrading strain D3-1 is combined with the denitrifying strain WH-01, the resulting TN removal rate surpasses that of a single denitrifying bacterium. In conclusion, as a carbon source in municipal sewage treatment, the degraded maize straw flour produced by strain D3-1 holds potential as a substitute for the glucose carbon source, and strain D3-1 has a synergistic effect with the denitrifying strain WH-01 on TN elimination. Thus, this research offers new insights and directions for advancement in environmental sewage treatment. Full article

The need for renewable and eco-friendly materials is driving the increasing demand for biobased polymers for food applications, with cellulose emerging as a promising option due to its degradability and environmental sustainability. Therefore, in the present study, a strategy to obtain cellulose-based materials with antimicrobial properties was explored by using a selected antimicrobial peptide named RKT1, which was stably and efficiently tethered to cellulose films via physical adsorption, harnessing the high number of functional groups on the polymeric surface. Firstly, the peptide, identified among the previous or new projected compounds, was structurally and functionally characterized, evidencing high conformational stability under a wide range of environmental conditions and efficient antibacterial activity against the foodborne pathogens Escherichia coli, Salmonella Typhimurium, and Listeria monocytogenes and the spoilage bacteria Enterococcus and Pseudomonas koreensis, all isolated from meat products. Moreover, in an extended application, the RKT1-activated cellulose films were tested in vivo on beef carpaccio. The results supported their effectiveness in increasing the shelf life of carpaccio by least two days without affecting its organoleptic properties. Therefore, RKT1, physically adsorbed on cellulose, still retains its activity, and the newly generated biopolymers show potential for use as a green food packaging material. Full article

To investigate the relationship between the rhizosphere microbial community structure and lotus root texture, the biological properties, and the rhizosphere microbial composition of mealy (ML) and crunchy lotus (CL) varieties were all analyzed using traditional and high-throughput sequencing technologies. The results showed that the ML varieties exhibited significantly lower moisture but higher starch contents than those of CL. Meanwhile, the rhizosphere fungal richness of ML was also significantly higher than that of CL. Moreover, the relative abundances of bacterial phyla and genera, such as Nitrospirota, Bacteroidota, Proteobacteria, and Bacillus, alongside fungal phyla and genera, i.e., Ascomycota and Emericellopsis, were enriched in rhizosphere of ML compared to CL. Functional prediction also revealed that elevated nitrogen cycling, polysaccharide degradation and cellulose breakdown functions could be detected in ML, potentially driving starch accumulation and cell wall modification. These results suggest that rhizosphere microbial composition, particularly nitrogen-cycling bacteria and lignocellulose-degrading fungi, may contribute to texture formation between texture-differentiated lotus root varieties. Full article

Insects are often associated with diverse microorganisms that enhance their metabolism and nutrient assimilation. These microorganisms, residing in the insect’s gut, play a crucial role in breaking down complex molecules into simpler compounds essential for the host’s growth. This study investigates the diversity and functional potential of symbiotic bacteria in the gut of Arsenura armida (Lepidoptera: Saturniidae) larvae, an edible insect from southeastern Mexico, using culture-dependent and metagenomic approaches. Bacterial strains were isolated from different gut sections (foregut, midgut, and hindgut) and cultured on general-purpose media. Isolates were identified through 16S rRNA gene sequencing and genomic fingerprinting. Metagenomics revealed the bacterial community structure and diversity, along with their functional potential. A total of 96 bacterial strains were isolated, predominantly Gram-negative bacilli. Rapidly growing colonies exhibited enzymatic activity, cellulose degradation, and sugar production. Phylogenetic analysis identified eight genera, including Acinetobacter, Bacillus, Enterobacter, Pseudomonas, and others, with significant cellulose-degrading capabilities. Metagenomics confirmed Bacillota as the most abundant phylum. These complementary methods revealed abundant symbiotic bacteria with key metabolic roles in A. armida, offering promising biotechnological applications in enzymatic bioconversion and cellulose degradation. Full article

This study aimed to investigate the effects of Nano-cAMP on growth performance, gut development, and microbiota composition in broilers. A total of 108 21-day-old yellow-feathered female chicks were randomly divided into three groups with six replicates per group and six chicks per replicate according to the principle of consistent body weight. Experimental treatments included the following: (1) CON group (basal diet), (2) cAMP group (basal diet + 0.02 g/kg cAMP), and (3) Nano-cAMP group (basal diet + 0.37 g/kg Nano-cAMP liposomes). After a 21-day experimental period, results revealed the following: Compared with the CON group, the Nano-cAMP group exhibited a significantly reduced feed-to-gain ratio (p < 0.05). The cAMP group exhibited a significant increase in duodenal index (p < 0.05), whereas the Nano-cAMP group demonstrated greater jejunal villus height (p < 0.05). Both treatment groups showed significant upregulation of cholecystokinin (CCK) and secretin gene expression (p < 0.05). Analysis of alpha-diversity indices (Chao1, Shannon, Simpson) revealed no significant differences in jejunal and cecal microbiota composition between experimental groups (p > 0.05). Notably, the relative abundance of Firmicutes significantly increased (p < 0.05) in the cAMP and Nano-cAMP groups, whereas Proteobacteria, Gemmatimonadota, and Chloroflexi significantly decreased (p< 0.05). The combined relative abundance of three Lactobacillus genera and Bifidobacterium was obviously elevated. Linear discriminant analysis identified Bifidobacterium, Ruminococcus torques group, and uncultured_Thermoanaerobacterales_bacterium as dominant genera in the intestinal tract of Nano-cAMP group. In conclusion, dietary addition of Nano-cAMP promotes jejunal development, modulates appetite hormones mRNA expression, enhances absorption capacity, increases the relative abundance of intestinal probiotics such as Bifidobacterium and cellulose-degrading bacteria such as Ruminococcus torques group, optimizes gut microbiota composition, and ultimately reduces the feed-to-gain ratio in broilers. Full article

Annually, a considerable amount of agricultural waste is produced leading to serious environmental pollution if not managed effectively. A wide range of bio-decomposers, including fungi, bacteria, and actinomycetes may break down the complex agro-residues in an eco-friendly way through secreting many cellulolytic and amylolytic enzymes. The present study aimed at exploring the ability of Frankia to degrade cellulose and starch and identifying the cellulase and α-amylase genes in Frankia genomes for potential agricultural waste degradation. Frankia alni ACN14a and Frankia casuarinae CcI₃ produced clear zones around growing hyphae on carboxymethyl cellulose (CMC) and starch substrates. The hydrolytic index (HI) ranged from 1 to 2.14 reflecting variation in their degradation efficacy. Quantification of CMCase (carboxymethyl cellulase) production in strain ACN14a presented the maximum activity (0.504 U/mL) under 1% CMC after 16 days whereas strain CcI₃ produced a weak activity after 6 days from incubation. Besides, amylase activity in strain ACN14a reached the highest value (3.215 U/mL) after 4 days of growing with 1% starch, while strain CcI₃ had the superior production (3.04 U/mL) after 12 days from 1% starch condition. Data mining and genome blasting led to the identification of multiple genes related to cellulose and starch degradation. Two endoglucanases (celA1, FRAAL4955 and celA2, FRAAL4956), two glycosyl hydrolase family 16 (FRAAL6120 and FRAAL2663), and one glycosyl hydrolase family 16 (Francci3_3843) were predicted in the two genomes. Likewise, the α-amylase genes (FRAAL5900) from Frankia alni ACN14a and (Francci3_3679) from strain CcI₃ were identified. The gene expression of endo-1, 4-beta-glucanase (celA2, FRAAL4956) revealed the maximum increment in its mRNA abundance under 0.25% CMC exposure and showed a 3.3-fold increase. Frankia capability to degrade cellulose and starch represents a critical process in nutrient cycling and environment protection. Full article

As high-quality sheep germplasm resources in China, Hu sheep are characterized by fast growth and development, high fecundity, and tolerance to drought and cold. Tibetan sheep, adapted to high-altitude environments, have developed strong environmental adaptability. To explore the differences in the interaction among rumen microbial flora, hepatic gluconeogenesis, and mitochondrial function between Tibetan sheep and Hu sheep in the Qinghai–Tibet Plateau, this study systematically compared and analyzed the rumen flora density, key enzyme activities related to hepatic gluconeogenesis and mitochondrial function, and the expression levels of related genes in Tibetan sheep and Hu sheep under identical feeding management conditions, followed by correlation analysis. The results showed that Hu sheep had significantly higher densities of Ruminobacteramylophilus (Ram) and Fibrobacter succinogenes (Fs) associated with starch and protein degradation (p < 0.01). The expression levels of Forkhead box O1 (FOXO1), pyruvate carboxylase (PC) activity, and adenosine triphosphate (ATP) content were also significantly higher than those in Tibetan sheep (p < 0.01). In contrast, Tibetan sheep had higher densities of Butyrivibrio fibrisolvens (Bf), Ruminococcus albus (Ra), Ruminococcus flavefaciens (Rf), etc., related to cellulose degradation (p < 0.01). The gluconeogenesis-related genes, Glucose-6-phosphatase catalytic subunit 1 (G6PC1) and phosphoenolpyruvate carboxykinase1 (PCK1), and the activities of phosphoenolpyruvate carboxykinase (PEPCK) and fructose-1,6-bisphosphatase (FBPase) were significantly higher in Tibetan sheep than in Hu sheep (p < 0.01). Mitochondrial function-related genes Mitofusin-1 (Mfn1), Mitofusin-2 (Mfn2), subunit 6 of ATP synthase (ATP6), cytochrome b (Cytb), etc., also showed significantly higher expression in Tibetan sheep (p < 0.01). While no significant differences were observed in the contents of citric acid (CA), pyruvic acid (PA), glucose (Glu), etc. (p > 0.05). Correlation analysis indicated that rumen flora was associated with the key enzyme activities and gene expressions of hepatic gluconeogenesis and mitochondrial function to varying degrees. In summary, Tibetan sheep exhibit strong fiber degradation capacity, the efficient utilization of gluconeogenic intermediates, and mitochondrial oxidative phosphorylation (OXPHOS) ability, forming adaptive strategies for high-altitude environments. By contrast, Hu sheep show efficient protein and starch degradation capacity, thereby enhancing the supply of gluconeogenic precursors. It is indicated that when introducing Hu sheep to high-altitude areas, dietary intervention can be used to regulate rumen microorganisms, such as increasing fiber-decomposing bacteria or enhancing mitochondrial oxidative capacity, to counteract metabolic limitations induced by hypoxia. Full article

This review first provides an overview of the functional diversity of Orthoptera-associated microbiota and the services they provide to their hosts. However, data are widely scattered across the different families studied, making it difficult to establish whether a core microbiota is present. The abundance of some genera (Pantoea, Enterococcus, Enterobacter, Acinetobacter) is associated with the degradation of cellulose compounds, although their clear contribution remains to be determined. In addition, P. agglomerans may play a role in the production of aggregation pheromones in the desert locust. In terms of gut compartmentalisation, the diversity of the bacterial community in the foregut appears to be highly variable between individuals and species, whereas it is more uniform in other parts of the gut. Metabolic pathways of the gut microbiota revealed differences in amino acid metabolism between the midgut and hindgut. Bacteria in the midgut are associated with amino acid synthesis and anaerobic metabolism, whereas pathways in the hindgut may be involved in amino acid catabolism and ace-tyl-CoA-mediated processes. Further research is needed to better understand these different components of the bacterial community in digestive processes, and to identify bacterial species of particular interest in explaining species’ lifestyles or for bioconversion. Full article

Objectives: This study engineered a colon-targeted drug delivery system (CTDS) using the dual pharmaceutical and edible properties of Pueraria lobata to encapsulate Lactobacillus paracasei for Type 2 diabetes mellitus (T2DM) therapy. Methods: The CTDS was designed as a core–shell composite through microwave–hydrothermal engineering, comprising the following: (1) a retrograded starch shell with acid/enzyme-resistant crystallinity to protect probiotics from gastric degradation; (2) a porous cellulose core derived from Pueraria lobata’s natural microstructure, serving as a colonization scaffold for probiotics. Results: Structural characterization confirmed the shell’s resistance to acidic/pancreatic conditions and the core’s hierarchical porosity for bacterial encapsulation. pH/enzyme-responsive release kinetics were validated via fluorescence imaging, demonstrating targeted probiotic delivery to the colon with minimal gastric leakage. In diabetic models, the CTDS significantly reduced fasting blood glucose and improved dyslipidemia, while histopathological analysis revealed restored hepatic and pancreatic tissue architecture. Pharmacologically, the system acted as both a probiotic delivery vehicle and a microbiota modulator, selectively enriching Allobaculum and other short-chain fatty acid (SCFA)-producing bacteria to enhance SCFA biosynthesis and metabolic homeostasis. The CTDS further exhibited direct compression compatibility, enabling its translation into scalable oral dosage forms (e.g., tablets). Conclusions: By integrating natural material engineering, microbiota-targeted delivery, and tissue repair, this platform bridges the gap between pharmaceutical-grade probiotic protection and metabolic intervention in T2DM. Full article

Lignocellulose, as Earth’s most abundant renewable biomass, represents a crucial resource for the production of biofuels and biochemicals, it is of great significance for sustainable development. Microbial degradation offers a promising pathway for transforming lignocellulose into valuable products. This review explores the diversity and classification of lignocellulose-degrading microorganisms, focusing on fungi and bacteria and their respective enzyme systems responsible for breaking down cellulose, hemicellulose, and lignin. Key factors influencing degradation efficiency, including environmental conditions, substrate complexity, and microbial interactions, are thoroughly analyzed. Limitations in microbial degradation are also discussed, notably the need for identifying high-activity strains. Additionally, the review outlines future research directions, emphasizing the application of advanced technologies such as genomics, synthetic biology, and machine learning to optimize microbial degradation processes. These insights aim to enhance lignocellulose utilization efficiency, fostering its broader industrial and agricultural applications. Full article

Background/Objectives: Previous studies have shown varying efficacy of high-fiber diets containing different ingredients in abdominal aortic aneurysms (AAAs). This study aimed to identify which high-fiber diet protects against AAA in mice and elucidate the underlying mechanisms. Methods: This study compared inulin, cellulose, and chow diets in terms of their impact on aneurysm enlargement, elastin degradation, matrix metalloproteinase 2 and 9 expressions, CD3+ T cell and CD68+ macrophage infiltration, and macrophage differentiation. It also examined gut microbiota composition, focusing on Akkermansia, and evaluated intestinal barrier function and systemic inflammatory response. Results: The inulin diet, but not the cellulose diet, compared with the chow diet, reduced aneurysm enlargement, elastin degradation, matrix metalloproteinase 2 and 9 expressions, CD3+ T cell and CD68+ macrophage infiltration, and skewed macrophage towards M2 differentiation. The inulin diet enriched Akkermansia in both the small and large intestine. The inulin diet also enhanced the intestinal barrier by augmenting goblet cells, upregulating the gene related to the epithelial barrier and antibacterial peptides in the small intestine, and reducing circulating lipopolysaccharide and interleukin-1β levels. The inulin diet lowered the proportion of Ly6Chi monocytes and C-C chemokine receptor 2 expression on these cells in the bone marrow, reducing aneurysm infiltration. Administering Akkermansia to AAA mice decreased intestinal permeability and mitigated AAA. Conclusions: A diet rich in fermentable fiber inulin, as opposed to cellulose, alleviates AAA in mice. This beneficial effect is attributed to the enhanced presence of Akkermansia bacteria and improvement of the intestinal barrier. Full article

The burgeoning global silage industry has precipitated challenges related to the sustainable utilization of mycotoxin-contaminated silage. To understand the effect of bio-enhancement on lignocellulose degradation and mycotoxin reduction, mycotoxin-contaminated silage and rape straw were co-composted without (CK) or with different bacterial agents and their combinations. Compared to CK, the inoculation of Weissella paramesenteroides and Bacillus subtilis could increase the degradation rate of cellulose by 39.24% and lignin by 22.31% after composting. Inoculation of W. paramesenteroides and Paenibacillus sp. significantly enhanced cellulose and lignin degradation rates by 26.75% and 15.48%, respectively. Furthermore, this treatment significantly reduced mycotoxin levels (p < 0.05), including Aflatoxin B1 (AFB1, 64.48% reduction), T-2 toxin (65.02%), Ochratoxin A (OTA, 61.30%), Zearalenone (ZEN, 67.67%), and Vomitoxin (DON, 48.33%). Inoculation with Paenibacillus sp. and other bacteria increased total nitrogen by 48.34–65.52% through enhancing microbiological activity. Therefore, Paenibacillus sp. in combination with other bacteria could increase compost efficiency and reduce mycotoxin presence for better and safer utilization of agricultural waste by-products, enabling faster conversion of contaminated silage into safe soil amendments, which could reduce agricultural waste management costs. Full article

Total mixed ration silage has been used as a strategy to optimize the use of dry and wet feed in ruminant feeding. Another promising technique is silage reallocation, which allows producers to divide the ensiled material in large silos into smaller units that can be easily transported and marketed. Thus, this study aimed to improve food preservation through the development of total mixed rations (TMRs) based on relocated sorghum silage (RSS) and cactus pear for sheep diets. A completely randomized design was used with five treatments (0, 15, 25, 30, and 35% RSS inclusion on a dry matter basis) and five replicates. Ninety days after ensiling, the silos were opened. The fermentation characteristics, nutritional aspects, aerobic stability, and microbial populations of TMR silages were evaluated. The inclusion of RSS showed a quadratic effect on pH, density, permeability, lactic acid bacteria and yeast counts, and total carbohydrates (p < 0.05). It reduced gas and effluent losses, porosity, ammonia nitrogen, buffer capacity, ash, crude protein, ether extract, and non-fibrous carbohydrates (p < 0.05) while increasing dry matter, neutral and acid detergent fiber, hemicellulose, and cellulose contents (p < 0.05). There was an interaction effect between the levels of RSS inclusion and exposure times to air on CO₂ and dry matter content (p < 0.05). Regarding carbohydrate fractionation, there was a reduction in fraction A + B1 (non-fibrous carbohydrates) and an increase in fractions B2 (fibrous carbohydrates from the cell wall and of slow ruminal availability, susceptible to the effects of the passage rate) and C (indigestible neutral detergent fiber) (p < 0.05). For protein fractionation, a quadratic effect was observed for fractions A (non-protein nitrogen) and C (insoluble protein, indigestible in the rumen and intestine), an increase in fraction B1 (soluble protein rapidly degraded in the rumen) + B2 (insoluble protein with intermediate degradation rate in the rumen), and a reduction in fraction B3 (insoluble protein with slow degradation rate in the rumen) (p < 0.05) as RSS levels increased. Under the experimental conditions, it is recommended to include up to 30% RSS in the total mixed ration silage to improve microbiological characteristics, reduce gas and effluent losses, and increase dry matter recovery and nutritional aspects of silage when associated with cactus pear. Full article

The biochemical degradation of abundant cellulosic biomass for industrial use and energy production has been extensively researched in recent years. Some elaborate cellulose digestion approaches have been developed based on specialized bacteria, which possess sophisticated mechanisms to efficiently degrade recalcitrant natural carbohydrates. In this study, we assembled catalytic domains from multiple cellulolytic enzymes onto a scaffold along with a cellulose-binding module (CBM), specifically targeting crystalline cellulose. The catalytic domains of endoglucanase and cellobiohydrolase from Acetivibrio thermocellus were linked to a heterotrimeric protein scaffold that assembles in a specific order. The bicatalytic complex failed to show the anticipated synergistic effect in cooperative cellulolysis, presumably because the catalytic domains only serve as weak anchors for each other in binding to the substrate. On the other hand, cellulose digestion was remarkably promoted by incorporating a CBM into a stable complex with a catalytic domain. Interestingly, the reversible association of catalytic domains and excess CBM proved more advantageous than fixed association. This suggests that the dynamic incorporation of CBM units enhances the accessibility of cellulose-degrading catalytic modules to the polysaccharide strand by preventing overly strong binding. This finding could have interdisciplinary applications for enzymes converting polymeric substrates other than cellulose. Full article