This study describes and validates a new method for metagenomic biomarker discovery by way of class comparison, tests of biological consistency and effect size estimation. This addresses the challenge of finding organisms, genes, or pathways that consistently explain the differences between two or more microbial communities, which is a central problem to the study of metagenomics. We extensively validate our method on several microbiomes and a convenient online interface for the method is provided at http://huttenhower.sph.harvard.edu/lefse/.

Metagenomic biomarker discovery and explanation

Universal sample preparation method for proteome analysis

Extensive documentation on the antimicrobial properties of essential oils and their constituents has been carried out by several workers. Although the mechanism of action of a few essential oil components has been elucidated in many pioneering works in the past, detailed knowledge of most of the compounds and their mechanism of action is still lacking. This knowledge is particularly important for the determination of the effect of essential oils on different microorganisms, how they work in combination with other antimicrobial compounds, and their interaction with food matrix components. Also, recent studies have demonstrated that nanoparticles (NPs) functionalized with essential oils have significant antimicrobial potential against multidrug- resistant pathogens due to an increase in chemical stability and solubility, decreased rapid evaporation and minimized degradation of active essential oil components. The application of encapsulated essential oils also supports their controlled and sustained release, which enhances their bioavailability and efficacy against multidrug-resistant pathogens. In the recent years, due to increasingly negative consumer perceptions of synthetic preservatives, interest in essential oils and their application in food preservation has been amplified. Moreover, the development of resistance to different antimicrobial agents by bacteria, fungi, viruses, parasites, etc. is a great challenge to the medical field for treating the infections caused by them, and hence, there is a pressing need to look for new and novel antimicrobials. To overcome these problems, nano-encapsulation of essential oils and exploiting the synergies between essential oils, constituents of essential oils, and antibiotics along with essential oils have been recommended as an answer to this problem. However, less is known about the interactions that lead to additive, synergistic, or antagonistic effects. A contributing role of this knowledge could be the design of new and more potent antimicrobial blends, and understanding of the interplay between the components of crude essential oils. This review is written with the purpose of giving an overview of current knowledge about the antimicrobial properties of essential oils and their mechanisms of action, components of essential oils, nano-encapsulated essential oils, and synergistic combinations of essential oils so as to find research areas that can facilitate applications of essential oils to overcome the problem of multidrug-resistant micro-organisms.

Antimicrobial Activity of Some Essential Oils-Present Status and Future Perspectives.

Circadian clocks coordinate physiology and behavior with the 24h solar day to provide temporal homeostasis with the external environment. The molecular clocks that drive these intrinsic rhythmic changes are based on interlocked transcription/translation feedback loops that integrate with diverse environmental and metabolic stimuli to generate internal 24h timing. In this review we highlight recent advances in our understanding of the core molecular clock and how it utilizes diverse transcriptional and post-transcriptional mechanisms to impart temporal control onto mammalian physiology. Understanding the way in which biological rhythms are generated throughout the body may provide avenues for temporally directed therapeutics to improve health and prevent disease.

Molecular Architecture of the Mammalian Circadian Clock

Polyphenols are categorized as plant secondary metabolites, and they have attracted much attention in relation to human health and the prevention of chronic diseases. In recent years, a considerable number of studies have been published concerning their physiological function in the digestive tract, such as their prebiotic properties and their modification of intestinal microbiota. It has also been suggested that several hydrolyzed and/or fission products, derived from the catabolism of polyphenols by intestinal bacteria, exert their physiological functions in target sites after transportation into the body. Thus, this review article focuses on the role of intestinal microbiota in the bioavailability and physiological function of dietary polyphenols. Monomeric polyphenols, such as flavonoids and oligomeric polyphenols, such as proanthocyanidins, are usually catabolized to chain fission products by intestinal bacteria in the colon. Gallic acid and ellagic acid derived from the hydrolysis of gallotannin, and ellagitannin are also subjected to intestinal catabolism. These catabolites may play a large role in the physiological functions of dietary polyphenols. They may also affect the microbiome, resulting in health promotion by the activation of short chain fatty acids (SCFA) excretion and intestinal immune function. The intestinal microbiota is a key factor in mediating the physiological functions of dietary polyphenols.

https://www.mdpi.com/1420-3049/24/2/370/pdf

Role of Intestinal Microbiota in the Bioavailability and Physiological Functions of Dietary Polyphenols.

Studies on purification and the molecular mechanism of a novel ACE inhibitory peptide from whey protein hydrolysate

The modulatory effect of (-)-epigallocatechin 3-O-(3-O-methyl) gallate (EGCG3″Me) on intestinal microbiota of high fat diet-induced obesity mice model

Low-field NMR determination of water distribution in meat batters with NaCl and polyphosphate addition.

The aim of this study was to investigate the antibacterial activity of black pepper essential oil (BPEO) on Escherichia coli, further evaluate the potential mechanism of action. Results showed that the minimum inhibition concentration (MIC) of BPEO was 1.0 μL/mL. The diameter of inhibition zone values were with range from 17.12 to 26.13 mm. 2 × MIC treatments had lower membrane potential and shorter kill-time than 1 × MIC, while control had the highest values. E. coli treated with BPEO became deformed, pitted, shriveled, adhesive, and broken. 2 × MIC exhibited the greatest electric conductivity at 1, 3, 5, 7, 9, 11, and 13 h, leaked DNA materials at 4, 8, 12, 16, 20, 24, and 28 h, proteins at 4, 6, 8, 10, 12, 14, and 16 h, potassium ion at 0, 0.5, 1, 1.5, and 2 h, phosphate ion at 0.5, 1, 1.5, and 2 h and ATP (P < 0.05); 1 × MIC had higher values than control. BPEO led to the leakage, disorder and death by breaking cell membrane. This study suggested that the BPEO has potential as the natural antibacterial agent in meat industry.

/pdf/antibacterial-activity-and-mechanism-of-action-of-black-336ar0brwn.pdf

Jinxuan Cao

Papers

Studies on purification and the molecular mechanism of a novel ACE inhibitory peptide from whey protein hydrolysate

The modulatory effect of (-)-epigallocatechin 3-O-(3-O-methyl) gallate (EGCG3″Me) on intestinal microbiota of high fat diet-induced obesity mice model

Low-field NMR determination of water distribution in meat batters with NaCl and polyphosphate addition.

Antibacterial Activity and Mechanism of Action of Black Pepper Essential Oil on Meat-Borne Escherichia coli.

Occurrence, antimicrobial resistance and biofilm formation of Salmonella isolates from a chicken slaughter plant in China