2.1_Microorganisms in Industrial Microbiology and Biotechnology

Prokaryotes

are unicellular organisms that lack a nucleus and membrane-bound organelles.

Bacteria and Archaea

Prokaryotes are unicellular organisms that lack a nucleus and membrane-bound organelles. They include:

Bacteria

These are the most diverse group of microorganisms, found in various environments. They have a simple structure but can carry out complex biochemical processes, making them valuable in industrial applications.

Archaea

• Similar to bacteria in structure but differ in their genetic and metabolic pathways.

• They can thrive in extreme environments, such as high temperatures (thermophiles) or high salinity (halophiles), and are used in biotechnology for biofuel production and bioremediation.

• are prokaryotic microorganisms distinct from bacteria, often thriving in extreme environments (high temperature, acidic or alkaline pH, high salt).

• Their unique enzymes and metabolic pathways have attracted attention for specialized industrial processes.

Fungi, Algae, Protozoa

Eukaryotic microorganisms possess a nucleus and membrane-bound organelles, allowing for compartmentalized metabolic activities. They include:

Fungi

Eukaryotic microorganisms:

• Yeasts and molds are widely used in fermentation, enzyme production, and antibiotic synthesis.

Algae

Eukaryotic microorganisms:

• Microalgae are used in biofuel production, pharmaceuticals, and as a source of food supplements (e.g., spirulina).

• range from unicellular microalgae to large multicellular macroalgae (seaweeds).

• Industrially, microalgae are of significant interest due to their high growth rates, photosynthetic efficiency, and ability to accumulate valuable biomolecules.

• are classified into several major groups (e.g., green algae (Chlorophyta), diatoms (Bacillariophyta), and red algae (Rhodophyta)) based on pigment composition, cell wall structure, and other morphological traits.

• Despite their eukaryotic nature, they can exhibit tremendous diversity in structure and physiology.

Protozoa

Eukaryotic microorganisms:

• Though not commonly used in industry, some protozoa play roles in wastewater treatment and biocontrol applications.

classification and identification

The ____of industrially important microorganisms help optimize their use in biotechnology.

shape, Gram-staining properties, and metabolic characteristics

Bacteria are classified based on their _____

Lactobacillus

BACTERIA: Used in dairy fermentation for yogurt and cheese production.

Streptomyces

BACTERIA: Producers of antibiotics such as streptomycin and tetracycline.

Escherichia coli

BACTERIA: A model organism for genetic engineering and recombinant protein production.

Bacillus

BACTERIA: Producers of industrial enzymes like amylases and proteases.

Clostridium

BACTERIA: Used in biofuel production and solvent fermentation.

Saccharomyces cerevisiae

FUNGI: A yeast used in baking, brewing, and bioethanol production.

Aspergillus

FUNGI: Produces citric acid, enzymes, and antibiotics.

Penicillium

FUNGI: The source of the first antibiotic, penicillin, and other bioactive compounds.

Chlorella

ALGAE: Used in wastewater treatment and food supplements.

Spirulina (Arthrospira)

ALGAE: A cyanobacterium used as a protein-rich food supplement.

Dunaliella

ALGAE: Produces beta-carotene, a valuable antioxidant

Methanogens (Methanobacterium, Methanosarcina)

ARCHAEA: Used in biogas production.

Thermophiles (Thermococcus, Pyrococcus)

ARCHAEA: Produce thermostable enzymes used in industry.

Taxonomy

is the science of naming, defining, and classifying organisms into groups based on shared characteristics and evolutionary relationships.

morphological traits and biochemical characteristics

Traditionally, microorganisms were classified primarily by ______ (e.g., shape, size, presence of specific structures) and _____(e.g., metabolic pathways, nutrient usage).

ribosomal RNA (rRNA) and genomic sequences

modern molecular methods—particularly comparisons of ______—have revolutionized microbial taxonomy

• Identifying organisms with desirable traits or metabolites.

• Predicting related organisms that may have similar or improved characteristics for process optimization.

• Ensuring quality control by confirming the identity of production strains.

From an industrial perspective, taxonomy aids in:

Rapid Growth

Key Characteristics of BACTERIA:

• Many bacteria can double in number in under an hour, which is advantageous for large-scale product formation.

Diverse Metabolic Pathways

Key Characteristics of BACTERIA:

• Bacteria can metabolize various substrates (e.g., carbohydrates, hydrocarbons, inorganic compounds). This allows them to produce an array of metabolites—such as enzymes, antibiotics, amino acids, and organic acids—that have industrial applications.

Genetic Manipulation

Key Characteristics of BACTERIA:

• Bacterial genomes are relatively small and more easily manipulated, which facilitates the creation of genetically engineered strains optimized for high yields of desired products.

Adaptability

Key Characteristics of BACTERIA:

• Some bacteria thrive under extreme conditions (e.g., high temperature, low pH, high salinity), making them suitable for specialized industrial processes.

Enzyme Production

Industrial Applications of BACTERIA:

• Species from the genera Bacillus, Streptomyces, and Escherichia are prolific enzyme producers (e.g., amylases, proteases, lipases).

Fermentation

Industrial Applications:

• Lactobacillus species are central to dairy product fermentation (cheese, yogurt), while Acetobacter species are used to produce vinegar.

Biopesticides and Fertilizers

Industrial Applications of BACTERIA:

• Bacillus thuringiensis produces toxins used as biological insecticides, and nitrogen-fixing bacteria (e.g., Rhizobium) aid in sustainable agriculture.

Bioremediation

Industrial Applications of BACTERIA:

• Hydrocarbon-degrading bacteria (e.g., Pseudomonas) can help break down pollutants in soil and water.

Acetobacter species

BACTERIA: are used to produce vinegar

Yeasts

• are unicellular fungi primarily classified within the phylum Ascomycota (e.g., Saccharomyces cerevisiae) and, to a lesser extent, Basidiomycota.

Key Characteristics:

• Fermentative Metabolism: Yeasts like S. cerevisiae can ferment sugars into ethanol and carbon dioxide, underpinning the bread, beer, and bioethanol industries.

• Rapid Growth and Easy Cultivation: Their ability to grow quickly in simple media makes them cost-effective for large-scale applications.

• Genetic Tractability: S. cerevisiae is one of the most extensively studied eukaryotic model organisms, enabling precise genetic manipulation.

Molds

• primarily belong to the groups Ascomycota (e.g., Penicillium, Aspergillus) and Zygomycota (e.g., Mucor, Rhizopus).

Key Characteristics:

• Filamentous Growth: Mold cells form hyphae that can penetrate substrates, aiding in enzyme secretion and nutrient absorption. 2.

• Secondary Metabolite Production: Molds produce a wide array of metabolites, including antibiotics (e.g., penicillin from Penicillium) and organic acids (e.g., citric acid from Aspergillus niger). 3.

• Enzymatic Profile: Molds secrete high levels of extracellular enzymes (e.g., cellulases, proteases, lipases), beneficial for food, feed, and biofuel industries.

Fermentation

Industrial Applications of FUNGI:

• Yeasts (e.g., S. cerevisiae) for alcoholic beverages, baked goods, and industrial ethanol.

Antibiotic Production

Industrial Applications of FUNGI:

• Penicillium chrysogenum for penicillin and other β-lactam antibiotics.

Organic Acid Production

Industrial Applications of FUNGI:

• Aspergillus niger for citric acid, Aspergillus itaconicus for itaconic acid.

Enzyme Production

Industrial Applications of FUNGI:

• Aspergillus and Trichoderma species for commercial enzymes (amylases, cellulases, proteases).

F.A.O.E

(Fermentation, Antibiotic Production, Organic Acid Production, Enzyme Production)

Industrial Applications of FUNGI:

Aspergillus niger

FUNGI: Organic Acid Production - for citric acid

Aspergillus itaconicus

FUNGI: Organic Acid Production - for itaconic acid

Microalgae

• _____ are used in biofuel production, pharmaceuticals, and as a source of food supplements (e.g., spirulina)

• Industrially, ___are of significant interest due to their high growth rates, photosynthetic efficiency, and ability to accumulate valuable biomolecules.

unicellular microalgae to large multicellular macroalgae (seaweeds)

Algae range from _____

green algae (Chlorophyta), diatoms (Bacillariophyta), and red algae (Rhodophyta)

Algae are classified into several major groups

Production of High-Value Compounds

Key Characteristics of ALGAE:

• Many microalgae produce lipids for biofuel, pigments (e.g., β-carotene, astaxanthin), and proteins for nutraceuticals.

High Growth Efficiency

Key Characteristics of ALGAE:

• Some algae can exhibit rapid growth under optimal conditions, suitable for large-scale cultivation in photobioreactors or open ponds.

Nutrient Recycling

Key Characteristics of ALGAE:

• Algae can utilize wastewater streams, providing an eco-friendly route for nutrient removal and biomass production.

Photosynthetic Capability

Key Characteristics of ALGAE:

• Algae convert sunlight, CO₂, and nutrients into biomass, reducing reliance on fossil fuels for feedstock.

Photosynthetic Capability, Production of High-Value Compounds, High Growth Efficiency, Nutrient Recycling

Key Characteristics of ALGAE:

Biofuel Production

Industrial Applications of Algae:

• Certain algae strains accumulate high levels of lipids, which can be converted into biodiesel.

Nutraceuticals and Pharmaceuticals

Industrial Applications of Algae:

• Spirulina (Arthrospira) and Chlorella are sold as dietary supplements rich in proteins, vitamins, and antioxidants

Food and Feed Additives

Industrial Applications of Algae:

• Algal biomass can be processed into animal feed or used as thickening agents (e.g., carrageenan from red seaweeds).

Wastewater Treatment

Industrial Applications of Algae:

• Algae-based systems help in removing excess nutrients (N and P), thus reducing water pollution.

Biofuel Production, Nutraceuticals and Pharmaceuticals, Food and Feed Additives, Wastewater Treatment

Industrial Applications of Algae:

Stability in Extreme Conditions

Key Characteristics of ARCHAEA:

• Enzymes from thermophilic archaea (e.g., Thermus aquaticus, though technically a bacterium in the phylum Deinococcus-Thermus; archaea from genus Sulfolobus) remain active at high temperatures, useful in industrial reactions that require thermal stability.

Unique Metabolisms

Key Characteristics of ARCHAEA:

• Some archaea are methanogens producing methane as a metabolic byproduct, which can be harnessed for biogas production.

Robust Enzymes

Key Characteristics of ARCHAEA:

• Archaea produce extremozymes that are stable under harsh pH or salinity, suitable for applications in the chemical, textile, or pharmaceutical industries.

Stability in Extreme Conditions, Unique Metabolisms, Robust Enzymes

Key Characteristics of ARCHAEA::

Biocatalysis

Industrial Applications of ARCHAEA:

• Enzymes derived from extremophilic archaea enable reactions at conditions otherwise prohibitive for standard enzymes.

Biogas Production

Industrial Applications of ARCHAEA:

• Methanogenic archaea are vital in anaerobic digesters for converting organic waste into methane-rich biogas.

Mining and Bioleaching

Industrial Applications of ARCHAEA:

• Acidophilic archaea (e.g., Sulfolobus) assist in extracting metals from low-grade ores in environmentally friendly ways.

Biocatalysis, Biogas Production, Mining and Bioleaching

Industrial Applications of ARCHAEA:

Fermentative Metabolism

Key Characteristics of YEASTS:

• Yeasts like S. cerevisiae can ferment sugars into ethanol and carbon dioxide, underpinning the bread, beer, and bioethanol industries.

Rapid Growth and Easy Cultivation

Key Characteristics of YEASTS:

• Their ability to grow quickly in simple media makes them cost-effective for large-scale applications.

Genetic Tractability

Key Characteristics of YEASTS:

• S. cerevisiae is one of the most extensively studied eukaryotic model organisms, enabling precise genetic manipulation

Fermentative Metabolism, Rapid Growth and Easy Cultivation, Genetic Tractability

Key Characteristics of YEASTS:

Filamentous Growth

Key Characteristics of FUNGI:

• Mold cells form hyphae that can penetrate substrates, aiding in enzyme secretion and nutrient absorption.

Filamentous Growth, Secondary Metabolite Production, Enzymatic Profile

Key Characteristics of FUNGI:

Secondary Metabolite Production

Key Characteristics of FUNGI:

• Molds produce a wide array of metabolites, including antibiotics (e.g., penicillin from Penicillium) and organic acids (e.g., citric acid from Aspergillus niger).

Enzymatic Profile

Key Characteristics of FUNGI:

• Molds secrete high levels of extracellular enzymes (e.g., cellulases, proteases, lipases), beneficial for food, feed, and biofuel industries.

Biotechnology

is the use of biological systems, such as microorganisms, whole cells or their molecules, to solve problems or to make useful products

physical and chemical

Microbes must have the proper ____ conditions for growth

Temp, pH, Osmotic pressure

Physical requirements:

Oxygen, Carbon, Nitrogen

Chemical requirements:

Temperatures

Physical requirements:

• Microbes need optimum ___to grow and reproduce.

• Optimum ____is the temperature at which the organism grows the best.

Optimum Temperatures

is the temperature at which the organism grows the best.

Psychrophiles

Based on temperature microbes can be grouped in to:

• to mean "liking low temperature", usually grow at temp between -10 and 20 °c.

Mesophiles

Based on temperature microbes can be grouped in to:

• usually grow at temperatures between 20 and 40 °c. (optimum approximately 37 °c).

Thermophiles

Based on temperature microbes can be grouped in to:

• capable of growth at high temperatures, about 40 to 90 20 °c.

Extreme thermophiles

Based on temperature microbes can be grouped in to:

• have optimal growth at 80 degrees or above.

hey have evolved to thrive at temperatures between 20C and 45C, which perfectly matches the normal human body temperature of 37C (98.6 F). This moderate temperature range allows them to efficiently infect, survive, and reproduce within the warm, nutrient-rich human host

Most human pathogens are mesophiles! WHY????

pH

refers to the acidity or alkalinity of a solution

Acidophiles

Based on pH microbes can be classified as:

• grow in acidic environment (pH <7).

Neutrophiles

Based on pH microbes can be classified as:

• grow in neutral environment (pH =7).

6.5 and 7.5.

Most bacteria grow best at pH ranging near neutrality, between pH ___

Alkalophiles

Based on pH microbes can be classified as:

• grow in alkaline environment (pH >7).

Osmotic pressure

Changes in osmotic concentrations in the environment may affect microbial cells.

Hypotonic solution (lower osmotic concentration)

water moves into the cell; cell swells and may result burst or lysis.

Hypertonic solution (higher osmotic concentration)

water moves out of the cell; membrane shrinks and results plasmolysis.

Isotonic solution (balanced osmotic concentration)

Water enters to the cell equals to the amount of leave from the cell; Cell remains normal.

Plezophile (Barophile)

Growth more rapid at high hydrostatic pressures

Aerobe

grows in presence of atmospheric oxygen (O2) which is 20% O2

Obligate aerobe

requires O2

Anaerobe

grows in the absence of O2

Obligate anaerobe

usually killed in presence of O2

Microaerophiles

requires 2-10% O2