BIOTECHNOLOGY & BIOFUEL GENERATION

Objectives

The student will be able to:

Explain the concept of biotechnology.
Name foods that are processed using micro-organisms.
Explain the role of micro-organisms in the production of alcoholic drinks and organic acids.
Explain the role of microbes in the pharmaceutical industry.
Explain the role of microbes in the tanning industry.
State other uses of microbes.
Explain the need for new sources of energy.

BIOTECHNOLOGY

The Concept of Biotechnology

Biotechnology is the industrial application of biochemistry, microbiology, chemical engineering, genetic engineering etc. in order to make the best use of the capabilities of micro-organisms, cultured tissues, cells, etc. for the benefit of mankind.

During the past 2-3 decades, biotechnology has brought total revolution and sophistication in various fields such as medicine, agriculture, industrial microbiology etc. For example, genetic engineering has made it possible to map the whole genome of an organism, to make gene transfers, gene cloning, etc. Recombinant DNA technology has helped to develop growth hormones, interferon, vaccines against viral and malarial diseases, etc.

Biotechnology has helped to increase the industrial production of alcohol, antibiotics, vitamins, hormones, antibodies etc. by developing new and more efficient strains of microorganisms. Biotechnology has helped not only in the disposal of domestic wastes but also evolved techniques to make use of the biomass as a source of bioenergy.

The use of micro-organisms in the manufacture of cheese, yoghurt, kenkey, bread, butter

Micro-organisms are a key component in both home and industrial food preparation. They are grouped into bacterial, fungi, protozoan and viruses. Useful micro-organisms such as Lactic acid bacteria are used to make yogurt, cheese, sour cream, buttermilk and other fermented milk products. Fungi such as yeast or moulds are used in the manufacture of beer, wine, and breads. They are also involved in fermentations to convert corn dough and other vegetable carbohydrates into ethanol to make beer, wine, or kenkey.

Ø Yoghurt: The bacteria used in making yoghurt are Lactobacillus bacteria. Milk contains a sugar called lactose. The bacteria are able to break this down to form lactic acid. The lactic acid both lowers the pH of the yoghurt, which helps to preserve it, and denatures milk proteins, which gives the yoghurt its sharp taste.

Ø Bread: In production of bread, added yeast (S. cerevisiae), feeds on the sugars present in the bread dough and produces the gas carbon dioxide. The carbon dioxide causes the dough to rise.

Ø Beer: The process of making beer is called brewing. It involves breaking the starch in the grains (malted barley and malted wheat) into a sugary liquid, called wort, and fermenting the sugars in the wort into alcohol and carbon dioxide by yeasts (Saccharomyces sp.). Hops are added to introduce a bitter taste and to serve as a preservative.

Ø Kenkey: microorganism in corn dough respire anaerobically to produce alcohol which gives taste to the kenkey.

Ø Cheese: Milk is inoculated with lactic acid bacteria and rennet. The lactic acid bacteria convert the sugar in milk (lactose) to lactic acid. The rennet contains rennin, an enzyme that converts a common protein in milk called caseinogen into casein. The casein precipitates out as a gel-like substance or curd. The cheese is allowed to age (ripen) for several months in a cool place to improve its taste and consistency.

Micro-organisms and Liquor Production

Microorganisms play a crucial role in liquor production, specifically in the fermentation process that converts sugars into alcohol. Here’s an overview of how microorganisms are involved in the production of various types of liquor:

1. Role of Microorganisms in Liquor Production

a. Yeasts

Primary Microorganism: Yeasts are the main microorganisms used in liquor production. They convert fermentable sugars into alcohol and carbon dioxide through fermentation.
Types of Yeasts:
- Saccharomyces cerevisiae: Commonly used in the production of beer, wine, and spirits. Known for its ability to tolerate high alcohol concentrations and produce desirable flavors and aromas.
- Saccharomyces pastorianus: Used in lager production; known for its ability to ferment at lower temperatures.
- Saccharomyces bayanus: Often used in champagne and other sparkling wines due to its tolerance of high sugar concentrations and pressure.

b. Bacteria

Role: Bacteria are used in specific stages of liquor production to influence flavor, acidity, and other characteristics.
Types of Bacteria:
- Lactobacillus: Used in the production of sour beers and in some traditional spirits to enhance flavor profiles.
- Acetobacter: Involved in the production of vinegar, which can sometimes be a part of the process for certain types of spirits.

2. Liquor Production Processes

a. Beer Production

Ingredients: Malted barley, hops, water, and yeast.
Process:
1. Malting: Barley grains are soaked in water, germinated, and dried to produce malt.
2. Mashing: Malt is mixed with hot water to extract fermentable sugars, creating wort.
3. Boiling: Wort is boiled with hops to add bitterness and aroma.
4. Fermentation: Yeast is added to the cooled wort to ferment the sugars into alcohol and carbon dioxide.
5. Conditioning: Beer is aged to develop flavors and carbonation.
6. Filtration and Packaging: Final product is filtered, carbonated if necessary, and packaged.

b. Wine Production

Ingredients: Grapes (or other fruits) and yeast.
Process:
1. Harvesting and Crushing: Grapes are harvested, crushed, and the juice is extracted.
2. Fermentation: Yeast is added to the juice to ferment the sugars into alcohol. The process occurs in tanks or barrels.
3. Aging: Wine is aged in barrels or tanks to develop flavors.
4. Filtering and Bottling: Wine is filtered and bottled.

c. Spirits Production

Ingredients: Various raw materials like grains, fruits, or sugarcane, and yeast.
Process:
1. Fermentation: Raw materials are mashed or crushed to extract sugars, which are then fermented by yeast to produce a low-alcohol liquid (wash or wort).
2. Distillation: The fermented liquid is heated in a still to separate alcohol from water and other components. The alcohol vapors are collected and condensed into a higher-proof spirit.
3. Aging (optional): Some spirits are aged in barrels to develop their flavors.
4. Dilution and Bottling: The spirit is diluted to the desired strength and bottled.

3. Microbial Control and Quality Assurance

Sanitation: Maintaining cleanliness and controlling microbial contamination is crucial to prevent unwanted microorganisms from affecting the fermentation process and the final product.
Yeast Management: Ensuring healthy yeast populations and managing yeast strains to achieve the desired flavor and alcohol content.
Monitoring: Regular testing for parameters like alcohol content, pH, and microbial contamination ensures product consistency and quality.

For more detailed information on microbial processes in liquor production, resources such as Brewing Science & Technology and Wine Science: Principles and Applications provide in-depth insights into these processes.

Microbes in the Tanning Industry

Microbes play a significant role in the tanning industry, particularly in the leather-making process. The use of microbes can help in various stages of leather production, offering environmentally friendly alternatives to traditional chemical methods. Here's an overview of how microbes are utilized in tanning and related processes:

1. Microbial Tanning Processes

a. Bacterial Tanning

Role: Certain bacteria can convert organic materials in animal hides into leather through a process known as bacterial tanning.
Process:
- Bacterial Fermentation: Bacteria such as Bacillus and Clostridium are used to ferment the hides. These bacteria break down collagen and other proteins in the hides, making them more amenable to tanning.
- Enzyme Production: The bacteria produce enzymes that help in the breakdown of non-collagenous proteins and fats, facilitating the leather formation.

b. Fungal Tanning

Role: Fungi, particularly certain types of molds and yeasts, can be used to modify and enhance the properties of leather.
Process:
- Fungal Fermentation: Fungi such as Aspergillus and Penicillium are used to degrade specific components of hides, such as fats and proteins. This modification can lead to better leather quality or unique textures.
- Laccase Enzymes: Fungi produce laccase enzymes that can catalyze oxidative reactions, leading to the cross-linking of collagen fibers, which is crucial for the leather’s durability.

2. Microbes in Leather Processing

a. Bacterial Dehairing

Role: Bacteria are used to remove hair from hides in a process known as bacterial dehairing or biocleaning.
Process:
- Bacterial Action: Bacteria such as Bacillus and Clostridium are employed to digest the keratin proteins in the hair and epidermis, making it easier to remove hair from the hides.

b. Enzymatic Degreasing

Role: Enzymes produced by microorganisms are used to remove grease and fats from hides.
Process:
- Enzyme Application: Enzymes such as lipases, produced by bacteria or fungi, break down fats and oils in hides, preparing them for further processing.

3. Environmental Benefits

Reduced Chemical Use: Microbial processes can reduce the need for harmful chemicals traditionally used in tanning, such as chromium and heavy metals, leading to a more environmentally friendly process.
Biodegradability: Enzymes and microbial products are often biodegradable, reducing the environmental impact of waste from leather production.

4. Challenges and Considerations

Control and Consistency: Managing microbial processes can be complex, requiring careful control of environmental conditions such as temperature, pH, and moisture to ensure consistent results.
Efficiency: While microbial methods offer environmental benefits, they may not always match the efficiency or cost-effectiveness of traditional chemical methods, requiring further research and optimization.

5. Future Directions

Research and Development: Ongoing research aims to enhance the efficiency and scalability of microbial tanning processes, making them more viable for large-scale leather production.
Integration with Traditional Methods: Combining microbial processes with traditional tanning methods could offer a balanced approach, leveraging the benefits of both approaches.

For more detailed information on the application of microbes in the tanning industry, resources such as the Journal of Cleaner Production and Applied Microbiology and Biotechnology provide comprehensive research and insights.

Microbes in Mining

Microbes play a crucial role in the mining industry, particularly in processes known as bioleaching and bioremediation. These microbial processes offer environmentally friendly alternatives to traditional mining methods and can help in the recovery of valuable metals and the treatment of mining waste. Here’s an overview of how microbes are utilized in mining:

1. Bioleaching

Bioleaching is a process that uses microorganisms to extract metals from ores and waste materials. This method is particularly useful for low-grade ores and can be more environmentally friendly compared to traditional chemical extraction methods.

a. Types of Microorganisms Used

Acidophilic Bacteria: These bacteria thrive in acidic environments and are commonly used in bioleaching. Examples include:
- Thiobacillus ferrooxidans: Oxidizes iron sulfides (like pyrite) to release iron and sulfuric acid, which helps in dissolving metals.
- Thiobacillus thiooxidans: Oxidizes sulfur compounds to produce sulfuric acid, which can aid in the dissolution of metal ores.
Iron- and Sulfur-Oxidizing Bacteria: These bacteria are involved in the oxidation of iron and sulfur, which are critical in the leaching of metals from ores.
- Leptospirillum ferrooxidans: Involved in the oxidation of ferrous iron, aiding in the bioleaching of metals.
Archaea: Some archaea, like Ferroplasma acidarmanus, also contribute to bioleaching by surviving and thriving in extremely acidic conditions.

b. Bioleaching Process

Ore Preparation: Ores are crushed and ground to increase surface area.
Leaching: Microorganisms are introduced to the ore in heaps or bioleaching tanks. They oxidize the metal-containing minerals, producing soluble metal ions.
Recovery: Metal ions are recovered from the solution through processes like solvent extraction or precipitation.

c. Advantages

Lower Environmental Impact: Reduces the need for toxic chemicals and generates less waste compared to conventional methods.
Cost-Effective: Can be more cost-effective for low-grade ores and tailings.
Sustainable: Utilizes natural processes to recover valuable metals, aligning with sustainable mining practices.

2. Bioremediation

Bioremediation uses microorganisms to clean up contaminated mining sites, including soil and water contaminated with heavy metals and other pollutants.

a. Microorganisms Used in Bioremediation

Heavy Metal-Resistant Bacteria: Bacteria that can tolerate and detoxify heavy metals. Examples include:
- Pseudomonas putida: Known for its ability to degrade various organic pollutants and heavy metals.
- Bacillus spp.: Certain strains are used to detoxify heavy metals in contaminated soil.
Fungi: Some fungi have the ability to secrete enzymes that break down contaminants and absorb heavy metals. Examples include:
- White Rot Fungi (e.g., Phanerochaete chrysosporium): Known for its ability to degrade lignin and absorb heavy metals.
Algae: Microalgae can be used to absorb and accumulate heavy metals from contaminated water.
- Chlorella spp.: Known for its high metal absorption capacity.

b. Bioremediation Process

Site Assessment: Identifying the contaminants and assessing the extent of pollution.
Microbial Application: Introducing or stimulating microorganisms at the contaminated site to degrade pollutants.
Monitoring and Maintenance: Regular monitoring of microbial activity and pollutant levels to ensure effective remediation.

c. Advantages

Eco-Friendly: Reduces the need for physical or chemical treatment methods that may generate additional waste.
Cost-Effective: Often less expensive compared to conventional cleanup methods.
Sustainable: Provides a long-term solution for managing contamination by harnessing natural processes.

3. Challenges and Considerations

Efficiency: Microbial processes can be slower compared to traditional methods and may require optimal environmental conditions.
Contaminant Variability: Different types of contaminants and site conditions may affect the efficiency of microbial processes.
Regulation and Safety: Proper management and monitoring are necessary to ensure that microbial interventions do not lead to unintended consequences.

4. Future Directions

Research and Development: Ongoing research aims to improve the efficiency and application of microbial processes in mining.
Integration with Conventional Methods: Combining microbial processes with traditional mining techniques could offer enhanced recovery and remediation solutions.

For more detailed information on microbial applications in mining, resources such as the Journal of Hazardous Materials and Minerals Engineering provide comprehensive research and insights.

BIOLOGICAL FUEL GENERATION

Biological fuel generation involves producing energy from biological materials through various processes. This approach leverages renewable resources and can contribute to sustainable energy solutions. Here's an overview of the key methods and technologies involved in biological fuel generation:

1. Biofuels

Biofuels are produced from organic materials and can replace conventional fossil fuels in various applications.

a. Ethanol

Source: Primarily produced from carbohydrates in crops like corn, sugarcane, and wheat.
Production Process:
- Fermentation: Yeasts or bacteria convert sugars into ethanol and carbon dioxide.
- Distillation: The ethanol is then separated from the fermentation mixture.
Uses: Can be used as a gasoline additive to reduce emissions or as a standalone fuel.

b. Biodiesel

Source: Made from vegetable oils, animal fats, or waste cooking oils.
Production Process:
- Transesterification: Oils or fats are reacted with methanol or ethanol to produce biodiesel and glycerin.
Uses: Can be used in diesel engines, often blended with conventional diesel.

c. Biogas

Source: Produced from the anaerobic digestion of organic waste such as manure, food scraps, and agricultural residues.
Production Process:
- Anaerobic Digestion: Microorganisms break down organic matter in the absence of oxygen, producing methane and carbon dioxide.
Uses: Can be used for electricity generation, heating, or as a fuel for vehicles.

2. Algae Biofuels

Algae biofuels are derived from algae and offer a high yield of biofuel per unit area compared to traditional crops.

Source: Algae, including microalgae and macroalgae (seaweeds).
Production Process:
- Cultivation: Algae are grown in open ponds or closed photobioreactors.
- Harvesting and Processing: Algae are harvested and processed to extract oils or convert biomass into biofuels.
Types: Includes algal biodiesel, bioethanol, and biogas.

3. Biomass Gasification

Biomass gasification converts solid organic materials into syngas (synthetic gas) through partial oxidation at high temperatures.

Source: Wood chips, agricultural residues, municipal solid waste.
Production Process:
- Gasification: Biomass is heated in a controlled environment with a limited amount of oxygen, producing a mixture of carbon monoxide, hydrogen, and methane.
- Syngas Utilization: The syngas can be used for electricity generation, heat production, or further processed into chemicals and fuels.

4. Hydrothermal Liquefaction

Hydrothermal liquefaction converts wet biomass into liquid biofuels using high pressure and temperature.

Source: Algae, food waste, agricultural residues.
Production Process:
- Hydrothermal Liquefaction: Biomass is subjected to high pressure and temperature in the presence of water, producing a bio-crude oil that can be further refined into fuels.
Uses: The bio-crude oil can be upgraded to produce diesel, gasoline, or other fuels.

5. Direct Microbial Fuel Cells (MFCs)

Microbial fuel cells use bacteria to convert organic matter directly into electrical energy.

Source: Organic waste, wastewater.
Production Process:
- Microbial Fuel Cells: Bacteria break down organic matter in an anode chamber, producing electrons and protons. The electrons flow through an external circuit to the cathode, generating electricity.
Uses: Mainly for wastewater treatment with energy recovery, potential for remote or off-grid power generation.

6. Cellulosic Biofuels

Cellulosic biofuels are produced from non-food plant materials, such as crop residues and wood.

Source: Agricultural residues, forestry residues, dedicated energy crops.
Production Process:
- Pre-treatment: Breaks down plant cell walls to release cellulose.
- Enzymatic Hydrolysis: Enzymes convert cellulose into fermentable sugars.
- Fermentation: Microorganisms convert sugars into bioethanol or other biofuels.
Uses: Can be used as an alternative to gasoline or diesel.

Advantages of Biological Fuel Generation

Renewable: Uses organic materials that can be replenished over time.
Reduced Greenhouse Gas Emissions: Can potentially reduce carbon emissions compared to fossil fuels.
Waste Management: Utilizes waste products, reducing the burden on landfills.

Challenges

Land Use: Some biofuel crops require significant land, which could compete with food production.
Energy Efficiency: The energy yield from some biofuels may be lower compared to fossil fuels.
Cost: Initial production costs can be high, and infrastructure for widespread adoption may be lacking.

For more information on biofuels and their development, resources such as the U.S. Department of Energy (DOE) and International Energy Agency (IEA) offer valuable insights and updates.