Note that this definition has two issues. There is no universally accepted definition of life. There is no universally accepted size threshold for being called a microbe (to my knowledge). I would go with a threshold of about $10^{-5}$ meters. Is a virus a microbe? A virus IS and IS NOT alive depending on the definition. Note btw, that the definition of what is alive…
STEC O157 strains of bovine origin (n = 102) that varied by source, and epidemiologically unrelated human clinical STEC O157 strains (n = 91) were used for polymorphism discovery (Additional data file 1) [, –]. Each strain was characterized as STEC O157 by an enzyme-linked immunosorbent assay using an O157 monoclonal antibody and multiplex PCR for stx1 , stx2 , eae…
Bacteria are a subset of prokaryotes and while very different, they still have some common features. Learning Objective Identify common bacterial traits Key Points Bacteria vary from species to species, thus assigning many common traits to bacteria is difficult. Bacterial species are typified by their diversity. Not all prokaryotes are bacteria, some are archaea…
It is possible to use non-toxic stains (such as ink for fountain pens) to stain yogurt bacteria in-vivo. Can one see bacteria using a compound microscope? The answer is a careful “yes, but”. Generally speaking, it is theoretically and practically possible to see living and unstained bacteria with compound light microscopes, including those microscopes which are used…
Look into our eyes. Look deep into our eyes. There are no such things as molds. All molds are actually fungi. That s a bunch of fungus. This surprised us when we first learned about it. We always heard about mold in the shower or mold on the bread. Mold is actually a type of fungus. It has a shape called a zygote to be exact. While yeasts are single celled fungi…
Cells/viruses vary in size mainly according to their function, components & requirements imposed by cell division/virus replication. Bacterial cells are so small because they need a large surface area to cell volume to take in nutrients. Bacteria accumulate nutrients from the environment by diffusion alone, and so adopt certain sizes and shapes so they can…
The differences between bacteria and viruses Author – Elaine Pendlebury BA BSc BVetMed DMS MRCVS Senior Veterinary Surgeon (Science & Welfare) PDSA Bacteria (singular is bacterium ) are one celled living organisms with complete genetic ‘codes’ made up of DNA and RNA. A virus is a section of DNA or RNA enclosed by a protein shell. Bacteria are over 100 times…
Cilia and flagella are motile cellular appendages found in most microorganisms and animals, but not in higher plants. In multicellular organisms, cilia function to move a cell or group of cells or to help transport fluid or materials past them. The respiratory tract in humans is lined with cilia that keep inhaled dust, smog, and potentially harmful microorganisms…
All living organisms are classified into groups based on very basic, shared characteristics. Organisms within each group are then further divided into smaller groups. These smaller groups are based on more detailed similarities within each larger group. This grouping system makes it easier for scientists to study certain groups of organisms. Characteristics such as…
Credit: TheAlphaWolf Wikimedia (CC BY-SA 3.0) Getting around in dirt is not easy for bacteria. Those that can move rely on water in which to swim, but soil is full of air pockets and dry particles (boulders, no doubt, to bacteria) that block progress. New research indicates, however, that the filaments of fungi may act as highways that enable soil bacteria to move…
Microbes are organisms that are microscopic, or extremely small. Learning Objective Explain the roles of microorganisms in ecosystems and biotechnology. Key Points Microbes serve many functions in almost any ecosystem on Earth, including decomposition and nitrogen fixation. Many microbes are either pathogens or parasitic organisms, both of which can harm humans. Terms…
Heterotrophic flagellates contribute significantly to the matter flux in aquatic and terrestrial ecosystems. Still today their quantification and taxonomic classification bear several problems in field studies, though these methodological problems seem to be increasingly ignored in current ecological studies. Here we describe and test different methods, the live-counting…
Abstract: From biofilm and colony formation in bacteria to wound healing and embryonic development in multicellular organisms, groups of living cells must often move collectively. While considerable study has probed the biophysical mechanisms of how eukaryotic cells generate forces during migration, little such study has been devoted to bacteria, in particular with…
Biological Agents, Work Practices, Safety Equipment, and Facility Design Specific to Each A very specialized research laboratory that deals with infectious agents is the biosafety lab. Whether performing research or production activities, when working with infectious materials, organisms or perhaps even laboratory animals, the proper degree of protection is of utmost…
