Microbial feed additives in ruminant feeding.

The main purposes of feed additives administration are to increase feed quality, feed utilization, and the performance and health of animals. For many years, antibiotic-based feed additives showed promising results; however, their administration in animal feeds has been banned due to some public concerns regarding their residues in the produced milk and meat from treated animals. Some microorganisms have desirable properties and elicit certain effects, which makes them potential alternatives to antibiotics to enhance intestinal health and ruminal fermentation. The commonly evaluated microorganisms are some species of bacteria and yeasts. Supplementing microorganisms to ruminants boosts animal health, feed digestion, ruminal fermentation, animal performance (meat and milk), and feed efficiency. Moreover, feeding microorganisms helps young calves adapt quickly to consume solid feed and prevents thriving populations of enteric pathogens in the gastrointestinal tract which cause diarrhea. Lactobacillus, Streptococcus, Lactococcus, Bacillus, Enterococcus, Bifidobacterium, Saccharomyces cerevisiae, and Aspergillus oryzae are the commonly used microbial feed additives in ruminant production. The response of feeding such microorganisms depends on many factors including the level of administration, diet fed to animal, physiological status of animal, and many other factors. However, the precise modes of action in which microbial feed additives improve nutrient utilization and livestock production are under study. Therefore, we aim to highlight some of the uses of microorganisms-based feed additives effects on animal production, the modes of action of microorganisms, and their potential use as an alternative to antibiotic feed additives.

Recent Trends and Advances of Co3O4 Nanoparticles in Environmental Remediation of Bacteria in Wastewater.

Antibiotic resistance is a formidable global threat. Wastewater is a contributing factor to the prevalence of antibiotic-resistant bacteria and genes in the environment. There is increased interest evident from research trends in exploring nanoparticles for the remediation of antibiotic-resistant bacteria. Cobalt oxide (Co3O4) nanoparticles have various technological, biomedical, and environmental applications. Beyond the environmental remediation applications of degradation or adsorption of dyes and organic pollutants, there is emerging research interest in the environmental remediation potential of Co3O4 nanoparticles and its nanocomposites on antibiotic-resistant and/or pathogenic bacteria. This review focuses on the recent trends and advances in remediation using Co3O4 nanoparticles and its nanocomposites on antibiotic-resistant or pathogenic bacteria from wastewater. Additionally, challenges and future directions that need to be addressed are discussed.

Molecular basis of an agarose metabolic pathway acquired by a human intestinal symbiont.

In red algae, the most abundant principal cell wall polysaccharides are mixed galactan agars, of which agarose is a common component. While bioconversion of agarose is predominantly catalyzed by bacteria that live in the oceans, agarases have been discovered in microorganisms that inhabit diverse terrestrial ecosystems, including human intestines. Here we comprehensively define the structure-function relationship of the agarolytic pathway from the human intestinal bacterium Bacteroides uniformis (Bu) NP1. Using recombinant agarases from Bu NP1 to completely depolymerize agarose, we demonstrate that a non-agarolytic Bu strain can grow on GAL released from agarose. This relationship underscores that rare nutrient utilization by intestinal bacteria is facilitated by the acquisition of highly specific enzymes that unlock inaccessible carbohydrate resources contained within unusual polysaccharides. Intriguingly, the agarolytic pathway is differentially distributed throughout geographically distinct human microbiomes, reflecting a complex historical context for agarose consumption by human beings.