Project description:The purpose of this study was to explore the mechanism of aerobic decay of whole-plant corn silage and the effect of Neolamarckia cadamba essential oil on aerobic stability of whole-plant corn silage. Firstly, the dynamic changes of temperature, microbial community and metabolite content after aerobic exposure of whole-plant corn silage were determined, and the main microbial species and mechanism leading to aerobic spoilage of whole-plant corn silage were analyzed. The N. cadamba essential oil was extracted from fresh N. cadamba leaves by steam distillation, and the minimal inhibitory concentration, antibacterial stability and bacteriostatic mechanism of N. cadamba essential oil against undesirable microorganisms in whole-plant corn silage were determined. According to the minimum inhibitory concentration of N. cadamba essential oil on undesirable microorganisms in silage, N. cadamba essential oil was added to whole-plant corn silage to explore the effect of N. cadamba essential oil on the aerobic stability of whole-plant corn silage.
Project description:The structure and function of the microbiome inhabiting the rumen are, amongst other factors, mainly shaped by the animal’s feed intake. Describing the influence of different diets on the inherent community arrangement and associated metabolic activities of the most active ruminal fractions (bacteria and archaea) is of great interest for animal nutrition, biotechnology and climatology. Samples were obtained from three fistulated Jersey cows rotationally fed with corn silage, grass silage or hay, each supplemented with a concentrate mixture. Samples were fractionated into ruminal fluid, squeezed solid and solid matter. DNA, proteins and metabolites were analyzed subsequently. DNA extracts were used for Illumina sequencing of the 16S rRNA gene and the metabolomes of rumen fluids were determined by 500MHz-NMR spectroscopy. Tryptic peptides derived from protein extracts were measured by LC-ESI-MS/MS and spectra were processed by a two-step database search for quantitative metaproteome characterization. Protein- and DNA-based datasets revealed significant differences between sample fractions and diets and affirmed similar trends concerning shifts in phylogenetic composition. Ribosomal genes and proteins belonging to the phylum of Proteobacteria, particularly Succinivibrionaceae, exhibited a higher abundance in corn silage-based samples while fiber-degraders of the Lachnospiraceae family emerged in great quantities throughout the solid phase fractions. The analysis of 8163 quantified bacterial proteins revealed the presence of 166 carbohydrate active enzymes in varying abundance. Cellulosome affiliated proteins were less expressed in the grass silage, glycoside hydrolases appeared in slightest numbers in the corn silage. Most expressed glycoside hydrolases belonged to families 57 and 2. Enzymes analogous to ABC transporters for amino acids and monosaccharides were more abundant in the corn silage whereas oligosaccharide transporters showed a higher abundance in the fiber-rich diets. Proteins involved in carbon metabolism were detected in high numbers and identification of metabolites like short-chain fatty acids, methylamines and phenylpropionate by NMR enabled linkage between producers and products. This study forms a solid basis to retrieve deeper insight into the complex network of gut microbial adaptation.
Project description:Insect pathogenic fungus Beauveria bassiana in one of the best studied insect biocontrol fungus, which infects insects by cuticle penetration. After breaking the cuticles, the fungus will propagate in insect hemocoel and kill insect hosts. It has also been found that the mycelia of B. bassiana can penetrate plant tissues to reach insect inside plant, e.g. corn borer (Ostrinia furnacalis), but do not cause damage to plants. The mechanism of fungal physiological plasticity is poorly understood. To accompany our genome sequencing work of B. bassiana strain ARSEF 2860, fungal transcriptional responses to different niches were studied using an Illumina RNA_seq technique. To examine fungal response to insect cuticle, conidia were inoculated on locust hind wings for 24 hours before used for RNA extraction. To evaluate fungal adaptation to insect hemocole, the fifth instar larvae of cotton bollworms were injected with spore suspension and fungal cells isolated by centrifugation in a step gradient buffer. To unveil the mechanism of interaction with plants, the fungus was grown in corn root exudates for 24 hours. After RNA sequencing, around three million tags were acquired for each sample and fungal transcriptional profiles were compared. Unveiling gene differential expression patterns when the insect biocontrol fungus Beauveria bassiana grown in insect hemocoel, corn root exudates and on insect cuticles.
Project description:Insect pathogenic fungus Beauveria bassiana in one of the best studied insect biocontrol fungus, which infects insects by cuticle penetration. After breaking the cuticles, the fungus will propagate in insect hemocoel and kill insect hosts. It has also been found that the mycelia of B. bassiana can penetrate plant tissues to reach insect inside plant, e.g. corn borer (Ostrinia furnacalis), but do not cause damage to plants. The mechanism of fungal physiological plasticity is poorly understood. To accompany our genome sequencing work of B. bassiana strain ARSEF 2860, fungal transcriptional responses to different niches were studied using an Illumina RNA_seq technique. To examine fungal response to insect cuticle, conidia were inoculated on locust hind wings for 24 hours before used for RNA extraction. To evaluate fungal adaptation to insect hemocole, the fifth instar larvae of cotton bollworms were injected with spore suspension and fungal cells isolated by centrifugation in a step gradient buffer. To unveil the mechanism of interaction with plants, the fungus was grown in corn root exudates for 24 hours. After RNA sequencing, around three million tags were acquired for each sample and fungal transcriptional profiles were compared.