During the stationary phase, cells switch to a survival mode of metabolism. As growth slows, so too does the synthesis of peptidoglycans, proteins, and nucleic-acids; thus, stationary cultures are less susceptible to antibiotics that disrupt these processes. In bacteria capable of producing endospor...
Streptomycetes are sessile bacteria that produce metabolites that impact the behavior of microbial communities. Emerging studies have demonstrated that Streptomyces spores are distributed through various mechanisms, but it remains unclear how spores are
Skim milk agar plates are used to provide a nutritious medium for growing micro-organisms. Once prepared, the agar can be plated with a population of micro-organisms to test for the micro-organism's ability to digest casein protein. Casein is a large ins
Does a high bacterial count in a food necessarily indicate that it is unsafe to eat? Why or why not? Suggest three ways in which food might become contaminated by harmful bacteria. You streak an unknown bacterium on AMP ...
Naturally occurring bacteria grow over 1–2 weeks to produce lactic acid, which then prevents the growth of food poisoning bacteria and other spoilage microorganisms. The amount of added salt controls the type and rate of the fermentation, and (ii) in sweet fermented pickles, they are preserved...
Although many bacteria grow in a free-living, ‘planktonic’ state, it is quite common for them to adhere to surfaces by producing extracellular polymeric substances (EPS), e.g. biofilms. Due to their higher resistance against antimicrobial agents, an interesting option in antibacterial research ...
transduction technique for transferring the second plasmid into strains that contained only the first.119 Theoretically the resulting fully virulent deriva- tive strain could be selected on agar culture plates, screened for the capsule production phenotype when grown in the presence of elevated carbon ...
The discovery of antibiotics has saved so many lives. The trouble with bacteria is that they adapt and evolve very quickly, which leads to antibiotic-resistant strains of bacteria. Measuring the zone of inhibition for a strain of bacteria can tell scient
This slide count does not discriminate between living spores and dead ones, but, since dead ones can still cause an allergic reaction and carry toxins, this subtlety is unimportant. The number of colonies that grow out over the agar in a culture dish usually provides a lower estimate of mold...
2019). Then the presence of phages is tested by visualization of plaques on plates containing the host, using the double-overlay agar method. In this technique, the host bacteria are mixed with phage filtrate and molten soft agar (Lee et al. 2012; Manohar et al. 2018; Fernández et al....