Module 3 SLP - microbial metabolic and environmental growth Essay

Module 3 SLP - microbial metabolic and environmental growth - Essay Example Different microbial species present varying degrees of thermal stability of its proteins and enzymes (Brooks et al., 2007). Hence, microorganisms display different temperature ranges that are optimal for their growth and metabolism. Those organisms which grow best at low temperatures (15-20 OC) are called psychrophiles. Mesophylic groups grow best at 30-37 OC while thermophilic forms grow best at a temperature range of 50-60 OC. According to a study conducted by Radke-Mitchell and Sandine (1986), L. bulgaricus has an optimum growth temperature range of 43-46 OC. On the other hand, E coli grows best at 37 OC, similar to the normal body temperature (Don, 2008). This is not surprising because E. coli forms a part of the body’s normal bacterial flora (Don, 2008). The significance of maintaining a certain range of pH for bacterial metabolism and growth is demonstrated by the fact that hydrogen ion concentration influences the integrity and functions of proteins, and other biochemical processes (Campbell and Reece, 2004). The acidity and alkalinity of the environment also affects the availability of nutrients essential for the growth of microorganisms. Those species that grow best at a pH range of 6.0-8.0 are called neutralophiles. Meanwhile, microorganisms with optimum pH growth of 3.0 or lower are classified as acidophiles while those with optima at a pH of 10.5 or higher are called alkaliphiles (Brooks et al., 2007). Beal et al. (2009) reported that L. bulgaricus achieve its highest biomass in culture when maintained at pH 5.0. Cell viability was also noted to be at its peak at pH 5.0 (Beal et al., 2009). On the other hand, the optimum pH for growth of E. coli is 6.0-8.0 (York et al., 1984). The process of energy production, termed respiration, operates by virtue of electron acceptors. Oxygen serves as an electron acceptor in bacterial respiration (Brooks et al., 20097). Organisms which strictly require oxygen for its