文摘
For various industrial manufacturing processes metalworking fluids (MWFs) are of high relevance due to their cooling and lubricating ability. Water-based MWFs are prone to the colonization by microorganisms which leads to deterioration and a change of the chemical composition with increasing duration of use. A wide range of species is able to colonize MWFs and metabolize almost all available substances (base oil and additives). However, it is known that some microorganisms are able to stabilize emulsions in nature by releasing biosurfactants into their environment. Considering that most microorganisms are not pathogenic and some of them are able to synthesize equivalent metalworking fluid components, the potential of microorganisms to act as a sustainable source for MWFs (here emulsifiers) components is investigated. This work presents an overview of the current state of science and the systematic selection of organisms according to certain criteria. The microbially produced biosurfactants were used to generate mineral-oil-free metalworking fluid emulsions with rapeseed oil. Results are presented which indicate the ability of microorganisms to replace emulsifying components of conventional water-miscible MWFs. Moreover, further bacterially produced substances are considered as replacements of metalworking fluid components and results are shown for lubricants produced by microorganisms.