This book provides a comprehensive overview of current biosurfactant research and applications. Public awareness of environmental issues has increased significantly over the last decade, a trend that has been accompanied by industry demands for climate-friendly and environmentally friendly renewable raw materials. In the context of household products, biosurfactants could potentially meet this demand in the future due to their low ecotoxicity, excellent biodegradability, and use of renewable raw materials.
The diversity of this class of molecules, which has only been marginally tapped to date, offers only an inkling of their future application potential. However, there are two main obstacles to their widespread commercial use on the growing surfactant market: the lack of attractive and competitive production technologies, and the limited structural diversity of commercially available biosurfactants. Addressing both of these core issues, this book will provide readers with a deeper understanding of the role of biosurfactants, including future opportunities and challenges.
Chapter “Environmental Impacts of Biosurfactants from a Life Cycle Perspective: A Systematic Literature Review” is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.
Author(s): Rudolf Hausmann, Marius Henkel
Series: Advances in Biochemical Engineering/Biotechnology, 181
Publisher: Springer
Year: 2022
Language: English
Pages: 272
Preface
Contents
Industrial Perspectives for (Microbial) Biosurfactants
1 Introduction
2 Surfactants, Biosurfactants, and Microbial Biosurfactants
3 The Trend for Biosurfactants
4 Opportunities and Restraints for (Microbal) Bio-surfactants
5 Ambitions of the Authors
References
Screening Strategies for Biosurfactant Discovery
1 Introduction
2 Screening Methods Based on Physical Properties
2.1 Universal Screening Assays
2.1.1 The Drop Collapse Test
2.1.2 Oil Spread Test
2.1.3 The Atomized Oil Spray Method
2.1.4 Microplate Assay
2.1.5 Penetration Assay
2.1.6 Tilting Slide Test
2.1.7 Victoria Pure Blue BO (VPBO) Assay
2.2 Targeted Screening Assays
2.2.1 Emulsification After 24 h (EC24)
2.2.2 Hemolytic Assay
2.2.3 Colorimetric Complex Release Assays
CTAB-Methylene Blue Plate Assay
CPC-Bromothymol Blue Assay
2.2.4 Detection of Biosurfactant Production by Thin Layer Chromatography (TLC)
2.2.5 Screening Methods Based on Cell Surface Hydrophobicity
Hydrocarbon Overlay Agar
Bacterial Adhesion to Hydrocarbon Test (BATH)
Hydrophobic Interaction Chromatography (HIC)
Replica Plate Test Assay: Adhesion of Bacteria to Hydrophobic Polystyrene
Salts Aggregation Assay
Solubilization of Crystalline Anthracene
2.2.6 Structure-Based Screening as a Recent Advance in Physicochemical Screening Methods
2.2.7 Quantitative Screening Methods Based on the Direct Measure of the Surface and Interfacial Tension
Du-Nouy-Ring Method
Wilhelmy Plate Method
Stalagmometric Method
Axisymmetric Drop Shape Analysis by Profile (ADSA-P)
Pendant Drop Shape Technique
3 In Silico Screening of Sequence Datasets for Novel Biosurfactants
3.1 Gene/Pathway Identification
3.2 Heterologous Expression of Putative Biosurfactant-Encoding Genes/Pathways Identified Through In Silico Mining
4 Metagenomic Biodiscovery: Unlocking Hidden Diversity
5 Coming Full Circle: Culturing Considerations to Unlock Novel Biosurfactant Potential
6 Concluding Remarks
References
Parameters Influencing Lipase-Catalyzed Glycolipid Synthesis by (Trans-)Esterification Reaction
1 Introduction
2 Deep Eutectic Solvents
2.1 Toxicity of DES
2.2 Biodegradability of DES
3 Enzymatic Synthesis
3.1 Different Lipases for Transesterification
3.2 Influence of Water Activity on Lipase-Catalyzed Transesterification
3.3 Influence of Sugar Loading on Enzymatic Glycolipid Synthesis
3.4 Influence of Fatty Acid Concentration on Transesterification Reactions
3.5 Influence of Solvent Hydrophobicity and Nucleophilicity on Lipase-Catalyzed Transesterification
4 Conclusion
References
Overview on Glycosylated Lipids Produced by Bacteria and Fungi: Rhamno-, Sophoro-, Mannosylerythritol and Cellobiose Lipids
1 Glycolipid Biosurfactants Produced by Bacteria
1.1 General Characteristics of GL Produced by Bacteria
1.2 RL General Characteristics and Industrial Applications
1.3 RL Synthesis and Regulation in P. aeruginosa
1.4 P. aeruginosa RL Biosynthesis Is Interrelated with the Synthesis of Polyhydroxyalkanoates (PHA)
1.5 Other Bacteria That Produce RL
1.6 Bioengineering Strategies for RL Production
1.7 Downstream Processing of RL
1.8 Genetic Engineering Strategies to Build Bacterial Strains with Enhanced RL Production
2 Glycolipid Biosurfactants Produced by Fungi
2.1 Different Strains to Produce Fungal Glycolipids
2.2 Structural Variety of SL, MEL, and CL in Wild-Type Strains
2.3 Metabolism and Genetic Engineering of Fungi
2.4 GL Produced by Fungi in a Bioreactor
2.5 Downstream Processing of Fungal GL
2.6 Physical Properties, Biological Activity, and Application Potential of Fungal GLs
2.6.1 SLs
2.6.2 MELs
2.6.3 CLs
3 Concluding Remarks
References
Bacillus sp.: A Remarkable Source of Bioactive Lipopeptides
1 Lipopeptide Biosynthesis and Natural Biodiversity
1.1 Nonribosomal Peptide Synthesis
1.2 Biodiversity of Surfactins
1.3 Biodiversity of Fengycins
1.4 Biodiversity of Iturins
1.5 Other Lipopeptides from Bacillus sp.
1.5.1 Antiadhesin
1.5.2 Bamylocin A
1.5.3 Circulocins
1.5.4 Kurstakins
1.5.5 Licheniformin
1.5.6 Locillomycins
2 Increasing Biodiversity by Genetic Engineering
2.1 Precursor Directed Biosynthesis
2.2 Specificity Code Mutations
2.3 Domain Exchange
2.4 Starter Units and Tailoring Modifications
3 Bioproduction in a Controlled Environment
3.1 Genetic Engineering Overproduction
3.1.1 Transcription
3.1.2 Increase in Precursor
3.1.3 Excretion
3.1.4 Degradation
3.2 Bioprocess Optimisation
3.2.1 Foaming Processes
3.2.2 Non-foaming Processes
Solid-State Fermentation
Immobilised Cells
Rotating Disc Reactor
Biofilm Reactors
Air Liquid Membrane Contactors
3.3 Purification
3.3.1 Acid Precipitation
3.3.2 Foam Fractionation
3.3.3 Adsorption
3.3.4 Membrane Ultrafiltration
3.3.5 Liquid/Liquid Solvent Extraction
3.3.6 Hybrid Methods
4 Biodiversity and Physicochemical Properties
4.1 Surface Activity
4.2 Self-assembly
4.3 Ion Complexation
5 Biodiversity and Biological Activities
5.1 Antimicrobial and Antifungal Activity
5.2 Cytotoxicity
5.3 Antiviral Activity
5.4 Anticancer Activity
5.5 Anti-inflammatory Activity
5.6 Immunomodulatory Activity
5.7 Induction of Systemic Resistance in Plants
5.8 Biofilm and Motility
6 Applications
6.1 Agriculture
6.2 Food
6.3 Environmental
6.4 Pharmaceutical
6.5 Detergent
6.6 Cosmetics
7 Conclusion
References
Achieving Commercial Applications for Microbial Biosurfactants
1 Introduction
2 Safety
3 Efficacy
3.1 Exploitation of Unique Biosurfactant Properties
4 Cost
5 Flexibility of Biosurfactants
References
Process Development in Biosurfactant Production
1 Introduction
2 Process Considerations
3 Organism Selection
4 Genetic Modification/Strain Selection
5 Reactor Type and Operation
5.1 Foam Fractionation Reactor
5.2 Membrane-Based Reactors
5.3 Slurry Bioreactors
5.4 Solid State Fermentation
5.5 Immobilised Cell or Biofilm Based Reactors
5.5.1 Immobilised Cells
5.6 Biofilm Support
5.7 Rotating Disc Bioreactors
5.8 In Situ Extraction Reactors
6 Media Composition
7 Downstream Processing
8 Final Use and Market
9 Conclusions
References
Environmental Impacts of Biosurfactants from a Life Cycle Perspective: A Systematic Literature Review
1 Introduction
2 Systematic Literature Research Approach
2.1 Search String Combinations
2.2 Definition of Relevance Criteria
2.3 Screening Procedure
2.4 Content Analysis Approach
3 Results
3.1 General Overview Over the Search Findings
3.2 Ecotoxicity of Biosurfactants: A Summary
3.2.1 Toxicity in LCA
3.3 Biodegradability of Biosurfactants: A Summary
3.3.1 Biodegradability in LCA
3.4 Systematic Analysis of Existing LCA Studies
3.4.1 LCA Studies of APGs
3.4.2 LCA Studies of Microbial Biosurfactants
4 Discussion of Findings in Published LCA Studies
5 Conclusions and Research Perspectives
References
