Actively growing cells transferred from one type of media into the same type of media, with the same environmental conditions, will have the shortest lag period. The length of the lag phase can vary considerably, based on how different the conditions are from the conditions that the bacteria came from, as well as the condition of the bacterial cells themselves. The lag phase is an adaptation period, where the bacteria are adjusting to their new conditions. But the pattern of four distinct phases of growth will typically remain. The details associated with each growth curve (number of cells, length of each phase, rapidness of growth or death, overall amount of time) will vary from organism to organism or even with different conditions for the same organism. For more information, write to my e-mail address:, via Wikimedia Commons If you use on your website or in your publication my images (either original or modified), you are requested to give me details: Michał Komorniczak (Poland) or Michal Komorniczak (Poland). Additionally, this growth curve can yield generation time for a particular organism – the amount of time it takes for the population to double. It has been determined that in a closed system or batch culture (no food added, no wastes removed) bacteria will grow in a predictable pattern, resulting in a growth curve composed of four distinct phases of growth: the lag phase, the exponential or log phase, the stationary phase, and the death or decline phase. Since bacteria are easy to grow in the lab, their growth has been studied extensively. The entire process or cell cycle can take as little as 20 minutes for an active culture of E. After the nucleoids are segregated to each end of the elongated cell, septum formation is completed, dividing the elongated cell into two equally sized daughter cells. The protein FtsZ is essential for the formation of a septum, which initially manifests as a ring in the middle of the elongated cell. The cell starts to replicate its DNA, in preparation for having two copies of its chromosome, one for each newly formed cell. The process begins with cell elongation, which requires careful enlargement of the cell membrane and the cell wall, in addition to an increase in cell volume. Other, less common processes can include multiple fission, budding, and the production of spores. Bacteria and archaea most commonly engage in a process known as binary fission, where a single cell splits into two equally sized cells. Bacterial Divisionīacteria and archaea reproduce asexually only, while eukartyotic microbes can engage in either sexual or asexual reproduction. While growth for muticelluar organisms is typically measured in terms of the increase in size of a single organism, microbial growth is measured by the increase in population, either by measuring the increase in cell number or the increase in overall mass. It’s important to have knowledge of their growth, so we can predict or control their growth under particular conditions. Depending on the situation, this could be a good thing for humans (yeast growing in wort to make beer) or a bad thing (bacteria growing in your throat causing strep throat). Provided with the right conditions (food, correct temperature, etc) microbes can grow very quickly.