Discuss how we can put microbes to work to improve our lives — from maintaining environmental cleanliness to producing nutritious foods and beverages.
Objectives:
Recognize the importance of microorganisms in water and sewage treatment systems.
Explain key concepts in food microbiology, emphasizing both prevention of infection and the roles of specific microbial taxa in food preparation.
Describe how microorganisms are utilized in industrial microbiology.
Suggested Search Terms:
Putting bacteria to work
Microbial fuel cell
Industrial microbiology biotechnology
Microbes in health care
Microbial taxa
Biotechnology and bacteria
Instructions:
Develop a three-to-five page written work summarizing the diverse ways humans employ microbes to their advantage. Consider their applications in areas such as food production, waste management, health care, and conversion of waste into usable fuel. Conclude by identifying which area of applied microbiology interests you most and explain its potential for future advancement.
Sample Answer
Harnessing the Invisible: Microbes for a Better Life 🦠
Microorganisms, though invisible to the naked eye, are fundamental to life on Earth and have been expertly harnessed by humanity for processes ranging from maintaining environmental cleanliness to producing a vast array of foods, beverages, and industrial products. Applied microbiology leverages the metabolic versatility of bacteria, fungi, algae, and archaea to benefit society in numerous ways.
Environmental Cleanliness: Water and Waste Management
Microorganisms are the unsung heroes of environmental maintenance, especially in the crucial areas of water and sewage treatment.3 Their natural role as decomposers is the core mechanism in these systems.
💧 Importance of Microorganisms in Water and Sewage Treatment
Wastewater and sewage contain a high concentration of organic matter, which must be removed before the water can be safely returned to the environment.4 The process is largely a biological one, relying on a diverse microbial community:5
Aerobic Degradation: In the activated sludge process and trickling filters (forms of secondary treatment), aerobic bacteria, such as those from genera like Pseudomonas and Bacillus, are supplied with oxygen (aeration) to rapidly consume and oxidize dissolved organic pollutants.6 They convert complex organic compounds into simpler substances like carbon dioxide, water, and new microbial cell mass (flocs).7 This process significantly reduces the Biochemical Oxygen Demand (BOD) of the water.
Nutrient Removal: Specialized microbial taxa are essential for removing nutrients like nitrogen and phosphorus, which can cause eutrophication (excessive algal growth) in receiving waters.
Nitrifying Bacteria (Nitrosomonas and Nitrobacter): These chemolithoautotrophs convert toxic ammonia (8$NH_3$) first into nitrite (9$NO_2^-$) and then into nitrate (10$NO_3^-$) in a two-step process called nitrification.11
Denitrifying Bacteria (Paracoccus, Pseudomonas): Under anoxic conditions, these microbes convert nitrate (12$NO_3^-$) into harmless nitrogen gas (13$N_2$), which is released into the atmosphere in a process called denitrification.14
Anaerobic Digestion: In the treatment of the resulting sludge (the concentrated solids), anaerobic bacteria, including methanogens (Methanobacterium), break down organic matter in the absence of oxygen.15 A valuable by-product of this process is biogas, a mixture rich in methane ($CH_4$) that can be used as a renewable fuel source.