The Volumetric Mass Transfer Coefficient

***Repeat steps 2-4 for each of the following: 5 mL of oil and 2 g each of cornstarch, sodium chloride, and sodium bicarbonate.

In the S. cerevisiae specimen, moderate growth was expected and observed based on the knowledge that most microbes desire this type of environment for growth. The same was expected although a larger amount of growth was observed for the S. epidermidis specimens in the 1% NaCl solution than expected. The 1% NaCl solution provided the best environment for the growth of both microbes. Minimal growth of S. cerevisiae and moderate growth of S. epidermidis was observed from the 7% NaCl solutions. The S. epidermidis is used to a slightly salty environment on the surface of skin which may account for the higher growth over S. cerevisiae in this environment. Lastly, no growth was noted in either specimen of 15% NaCl. This type of environment does not support the growth of most microbes due to the increase in salt content and the hypertonic environment it creates.

The lab for this paper was conducted for the topic of osmosis, the movement of water from high to low concentration. Five artificial cells were created, each being filled with different concentrated solutions of sucrose. These artificial cells were placed in hypertonic, hypotonic, or isotonic solutions for a period of 90 min. Over time, the rate of osmosis was measured by calculating the weight of each artificial cell on given intervals (every 10 minutes). The resulting weights were recorded and the data was graphed. We then could draw conclusions on the lab.

2) Yes, the rate of gas production increased as more yeast was added, since more enzyme was able to convert hydrogen peroxide more quickly.

Abstract: This lab’s purpose was to see how different levels of yeast, distilled water, and sugar interact to affect the level of carbon dioxide evolved in fermentation. In this experiment we had two sections. The first section tested four test tubes with varying levels of yeast, glucose and distilled water for evolved carbon dioxide levels. The tubes were timed for 20 minutes. The amounts of solution in the test tubes are noted in the methods section of this lab report. The second section of the lab used three test tubes and flowed the same procedure except added spices. The levels of ingredients are also in the methods section. The main goal of this experiment was to see the effects of yeast concentration.

In this lab, the organism that we have been working with is the bacterium, Serratia marcescens. S. marcescens is a member of the Enterobacteriaceae family, and tends to grow in damp environments. S. marcescens is an ideal bacterium to work with in the lab because it reproduces quicker than other bacterium. This bacterium produces a special pigment called prodigiosin, which is red in color. The prodigiosin pigment is intensified when S. marcescens is grown at higher densities. During our experiment, temperature, pH, salinity concentration and oxygen requirements were tested on S. marcescens to measure their optimal growth and prodigiosin production.

The reasoning behind this experiment is the examine whether the rate of osmosis is changed due to a change in temperature. It was hypothesized that the rate of osmosis will increase as the temperature of the sucrose is increased. The rate of osmosis was tested by using the different jars full of different temperate water and testing how high the water rose on an osmometer over a span of 20 minutes. An osmometer is a tool used to measure rates of osmosis. The different temperatures tested on a sucrose solution were 5 degrees Celsius, 20 degrees Celsius, and 37 degrees Celsius. Rates of osmosis were higher in the hot water than in the cold water and control. The results showed that the rate of osmosis increased as the temperature increased, henceforth the hypothesis was supported. In conclusion, the experiment showed how changes in temperature affect the rate of osmosis.

In the fourth stage of this experiment, the density of a gas was determined. A 250ml flask was weighed with an empty rubber balloon and the mass was recorded.

In order for growth to occur microorganisms need to obtain energy. One of those ways is by either the use of oxygen or not using oxygen. Microorganisms that require oxygen are obligate aerobes. It is essential for

This experiment is about bacterial growth. We will demonstrate a bacterial growth curve using a closed system. Bacterial growth usually takes up to 12-24 hours to get an accurate result so we will be monitoring this growth between two classes. We also used different methods to determine bacterial growth as well as a few different calculations. One way of receiving data is by using a spectrophotometer where we will record the absorption at a given time to create the bacterial growth curve. We also used the plate count method after performing a serial dilution to calculate the actual cell density at different times given. By using this method we can count the population number of the same given and see the maximum cell density

For diffusion and Gas Exchange to occur here they have to have a large surface area dependent on the size of the

For the experiment, the changes of temperature on anaerobic fermentation the process in which cells undergo respiration without oxygen in Saccharomyces cerevisiae was observed. The purpose of this experiment was to test the effect of four different temperatures on the rate of carbon dioxide production in yeast by measuring the fermentation rate. Saccharomyces cereviviae, also known as Baker 's yeast, is a unicellular, eukaryotic sac fungus and is good for this experiment because of its characteristic of alcohol fermentation. It was hypothesized that fermentation increases with increased temperature to a point of 37°C; above that point, enzyme denaturing will occur and fermentation will decrease. The group was able to document the carbon dioxide production and mark each of the temperature intervals which were tested at temperatures 4°C (refrigerator temperature), 23°C (Room temperature), 37°C (Human body temperature) and 65° Celsius (Equal to 150°F). The experiment was conducted by pouring yeast solution with 2% glucose in fermentation tubes, placing the tubes in the appropriate incubation temperature, marking the rise of the gas bubbles in the fermentation tubes which indicated carbon dioxide production. The results of this experiment were not supported by the hypothesis, creating different results from what was predicted. It is important to understand the fermentation rate of yeast so

Early studies have documented that bacterial growth increases in space flight; yet, the inherent mechanisms beholden to this growth have not been discovered. As the bacteria devour nutrients, they discharge corollary that can affect growth and impact ultimate cell population denseness. It is acknowledged that these metabolic processes charge a reduction in density of the fluid zone and the solute gradient about every cell. Along this planet, this fluctuation in density leads to an elasticity transfer of the expelled by-products. The fluid motion enclosing the cells can be changed through the restricting of the movement to just diffusion because of the lack of activity and deposit in the low-gravity space flight surroundings. From this biophysical representation, it was speculated that an increase in speed impacts the lag phase period and the final cell 's denseness of suspended cultures of bacteria in a deviating way. This is because of the modifications obtained in the extra cellular fluid constitution. Contained in the paper are experiments of different accelerations that frequently sustained this hypothesis, culmination in foreseeable growth kinetics. Other experiments show plumes of fluid that are visible to the naked eye emerging from metabolizing bacterial cultures. If related fluid kinetics were discovered to come about on a microscopic level, it might inform us of how acceleration impacts bacterium growth kinetics.

The rate of fermentation in this investigation was represented by the amount of carbon dioxide produced as a byproduct of fermentation in the given time.

The purpose of the two experiments was to determine the fundamental effects that temperature has on the growth and survival of bacteria. During the first experiment five different bacterial broth cultures of Escherichia coli, Pseudomonas fluorescens, Enterococcus faecalis, Bacillus subtilis and Bacillus stearothermophilus were individually incubated at temperatures of 5, 25, 37, 45 and 55°C for one week in an aim to distinguish the effect temperature has on growth and survival of the five different species. After one week they were observed for distinguishable changes by the turbidity showing an indication of bacterial growth, or the clarity an indication of no survival.