Project description:Degradation of polysaccharides forms an essential arc in the carbon cycle, provides a percentage of our daily caloric intake, and is a major driver in the renewable chemical industry. Microorganisms proficient at degrading insoluble polysaccharides possess large numbers of carbohydrate active enzymes, many of which have been categorized as functionally redundant. Here we present data that suggests that carbohydrate active enzymes that have overlapping enzymatic activities can have unique, non-overlapping biological functions in the cell. Our comprehensive study to understand cellodextrin utilization in the soil saprophyte Cellvibrio japonicus found that only one of four predicted b-glucosidases is required in a physiological context. Gene deletion analysis indicated that only the cel3B gene product is essential for efficient cellodextrin utilization in C. japonicus and is constitutively expressed at high levels. Interestingly, expression of individual b-glucosidases in Escherichia coli K-12 enabled this non-cellulolytic bacterium to be fully capable of using cellobiose as a sole carbon source. Furthermore, enzyme kinetic studies indicated that the Cel3A enzyme is significantly more active than the Cel3B enzyme on the oligosaccharides but not disaccharides. Our approach for parsing related carbohydrate active enzymes to determine actual physiological roles in the cell can be applied to other polysaccharide-degradation systems.
Project description:LubriShieldTM - a novel permanent coating was invented, and evenly applied to both the internal and external surfaces of indwelling urinary Foley catheters. Without releasing active substances, it effectively prevented pathogens from producing biofilm. The coating was superhydrophilic and incorporated a proprietary anti-fouling ligand, which created a surface that significantly inhibited up to 99% of colonizing uropathogens from forming biofilm for the duration of use without any microbial killing (p< 0.001).RNA-seq analysis revealed that gene expression associated with microbial extracellular polymeric substances formation was significantly downregulated on the coated surfaces. Additionally, microorganisms adhering to LubriShieldTM coated catheters were 78% more susceptible to antibiotics compared to those on uncoated silicone catheters (p=0.004).
Project description:The black soldier fly, Hermetia illucens, is a promising source for sustainable production of proteins, lipids and bioactive substances. Feeding on a variety of decomposing organic substrates which are typically inhabited by a range of different microorganisms like bacteria and fungi, H. illucens larvae is expected to be able to strongly produce antimicrobial peptides (AMPs) and other substances possessing antibiotic activity. It has been shown that H. illucens larvae extract exhibits antimicrobial activity against some microorganisms, such as Escherichia coli and Staphylococcus aureus, and antimicrobial effect on bacterial biofilm. Numbers of AMPs produced by H. illucens larvae have also been identified so far. Moreover, H. illucens larvae extract was recently observed with significant induction of cell envelop stress response (CESR) in B. subtilis, indicative of potential production of antimicrobial compounds. B. subtilis as a well-established Gram‑positive model strain is widely used in scientific research and an arguably robust platform to investigate antimicrobial compounds at the respect of, such as the mode of reaction of and the stress response elicited by corresponding compounds. In this study, we aimed to characterize the stress responses in B. subtilis induced by H. illucens larvae extract by employing transcriptomic study via RNA sequencing technique. With transcriptional profiling, we are expecting to be able to give some hints of potential antimicrobial compounds produced by H. illucens larvae by referring to the transcriptomic researches on well-studied antimicrobial substances.
Project description:Sea cucumbers (Holothuroidea; Echinodermata) have the capacity to regenerate lost tissues and organs.We used RNA-Seq to determine gene expression profiles associated with intestinal regeneration in A. japonicus at 3, 7, 14 and 21 days post evisceration (dpe)