Hop Acid Fermentation Control for PPFM Contamination
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Solution Overview
Problem
Large-scale fermentation of pink pigmented facultative methylotrophs (PPFMs) and methanotrophic bacteria is prone to contamination by gram-positive bacteria, leading to reduced biomass and recovery efficiency, which affects the yield and stability of fermentation products.
Innovation Solution
The use of hop acids, particularly beta acids, is employed to inhibit the growth of bacterial contaminants in the fermentation medium, maintaining a pH above 6 and concentrations of at least 7.5 ppm to 1000 ppm, allowing PPFM and methanotroph bacteria to thrive while controlling contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If large-scale fermentation is conducted to produce PPFM and methanotroph bacteria, then the quantity of inoculants for agricultural and industrial applications is increased, but contamination by gram-positive bacteria occurs leading to reduced biomass and recovery efficiency
Solution Approach 1:
The patent utilizes the natural antibacterial properties of hop acids (derived from hops used in brewing) to convert a potentially harmful substance into a beneficial contaminant control agent. Hop acids selectively inhibit gram-positive bacterial contaminants while allowing the desired PPFM and methanotroph bacteria to grow, thus transforming a chemical substance that could be harmful into a protective agent that enhances fermentation reliability during large-scale production
Solution Approach 2:
The patent changes the chemical environment of the fermentation medium by adding hop acids, which alters the selective pressure parameters. This parameter change creates conditions where contaminating gram-positive bacteria are inhibited while the target organisms (PPFM and methanotrophs) continue to thrive, thereby resolving the contradiction between large-scale production and contamination control
2Reliability
If hop acids are added to inhibit bacterial contaminants, then the stability and yield of fermentation products are improved, but the complexity of the fermentation medium increases
Solution Approach 1:
The patent introduces hop acids as an intermediary substance that mediates between the fermentation medium and contaminating bacteria. These acids act as a selective agent that naturally occurs in brewing processes, providing a bridge between existing industrial practices and the need for contamination control in PPFM and methanotroph fermentation, thereby improving stability without requiring entirely new complex systems
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively inhibits the growth of contaminants, enhancing the yield and stability of PPFM and methanotroph bacteria, thereby improving the efficiency and economic viability of the fermentation process.
Implementation Method 1
hop acids have been shown to have antibiotic/bacteriostatic effects against gram-positive bacteria without affecting brewing yeast at the optimum beer brewing pH range of 5.2-5.6
Data Source
AI summary
Methods and compositions for use in growth of pink-pigmented facultative methylotrophs (PPFM) and/or methanotroph bacteria are provided herein, wherein the fermentation comprises hop acids to inhibit growth of bacterial contaminants.