Microbial Biotechnology Overview

Microbial Biotechnology Overview

• Dr. Eman Owis, Lecturer of Microbial Biotechnology at Mansoura University, Göttingen University, Germany, is the presenter.
• Her contact email is [email protected]
• The lecture covers Microbial Biotechnology, focusing on fermentation, genetic engineering, nanotechnology, and applications in industry and pharmaceuticals.
• Topics include introduction to microorganisms, definitions, branches of biotechnology, factors influencing microbial activity, history and importance of bacteria and molds in industry and medicine, different types of microbial biotechnology techniques and safety and regulations.

Fermentation

• Fermentation is a biochemical process extracting energy from carbohydrates without oxygen.
• It's used to produce ethanol (wine), hydrogen (intestinal gas), lactic acid (cheese), and carbon dioxide (bread).
• The chemical equation for alcoholic fermentation is glucose → ethanol + carbon dioxide + energy (C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ + energy).

Fermented Foods

• Foods like soy sauce, cheese, yogurt, beer, and wine are produced through fermentation using bacteria and yeast.
• Different types of bacteria and yeast produce different end products.

Definitions of Fermentation

• Fermentation is alcohol production from grains and fruits (e.g., beer, wine).
• Souring of food is considered off/fermented.
• A desirable change to food or beverages through microorganisms; Hui (2004).

Screening and Isolation Methods

• Screening process identifies specific microorganisms, useful for industrial applications.
• Two types of screening: Primary and Secondary
• Primary screening detects microorganisms with potential.
• Secondary screening isolates microorganisms that produce certain products to improve.
• Different methods for isolating and screening organisms (disk plate, direct, serial dilutions, crowded plate methods).
• Isolation and screening of specific types like organic acid-producing bacteria.

Strain Improvement Techniques

• Strain improvement involves enhancing bacterial functions.
• Pathogenic and non-pathogenic strains can be isolated and improved.
• Techniques like genetic engineering are commonly used to improve microbes' functionality.

Fermentation Medium Requirements

• Nutrients for microbe growth include carbon, nitrogen, precursors, trace elements, inducers, buffer, and anti-foaming agents.
• Important factors to consider are growth factors, carbon sources, nitrogen sources, the production of certain substance.

Types of Fermentation Media (Submerged vs. Solid)

• Synthetic media has known composition. Easier and faster sterilization. Less time.
• Crude media contains unknown composition. More difficult and time-consuming sterilization to produce end product.
• Submerged fermentation in liquid medium, beneficial for high-moisture microbes like bacteria.
• Solid state fermentation involves cultivating microbes on solid substrates like grains, easier product separation and better energy efficiency.

Fermentation Types (Aerobic vs. Anaerobic)

• Aerobic fermentation requires oxygen and good aeration (e.g. antibiotics, enzymes, vitamins)
• In anaerobic fermentation, oxygen is not required (e.g. lactic acid, ethanol, wine)

Solid State Fermentation (SSF)

• Solid-state fermentation occurs in the absence of or minimal free water.
• It's used for producing enzymes, using natural raw materials (like barley, wheat bran, etc.).
• Examples include producing mushrooms, soy sauce, and organic acids.
• It is also beneficial as an alternative source of resources or materials.

Downstream Processes

• Downstream processes involve separating, extracting, purifying, and polishing microbial products for use.
• Includes separation of insolubles (filtration, centrifugation), extraction (solvent extraction, ultrafiltration), purification (chromatography), and polishing (crystallization, lyophilization, spray drying).

Submerged Fermentation

• Submerged fermentation uses liquid substrates (molasses, broths) for microbial growth and product production.
• Suitable for bacteria and other microbes that require high moisture.

Summary of Advantages/Disadvantages

• Benefits of solid-state fermentation: easier product separation, higher energy efficiency, lower contamination risk
• Benefits of submerged fermentation: easier purification of products, easier automation, higher product yield.