Microbial biotransformation strategies for green manufacturing antibiotics

Microbial biotransformation is now becoming a very promising green manufacturing process for antibiotics, and has emerged as one of the most sustainable alternatives to the pathways of conventional chemical synthesis, which are usually low in selectivity, highly wasteful, and intensive in solvent consumption. This review assesses the potential of whole cells and isolated enzyme systems for the selective molecular editing of a variety of deacylations, regioselective hydroxylations, and sugar remodelling reactions that proceed under mild and environmentally friendly conditions. The Quantitative greenness metrics including Environmental Factor (E-factor) and Process Mass Intensity (PMI) confirm that biocatalytic routes greatly reduce the use of toxic organic solvents, utility energy needs and hazardous process waste. In recent years, the empirical trial-and-error approach to biological processes has been replaced by programmable and highly predictive manufacturing platforms with the aid of new technologies such as synthetic biology, precision genome editing with CRISPR/Cas, metabolic flux engineering, multi-omics integration, and advanced biocatalyst immobilization. In conclusion, although there are still critical engineering challenges to address to ensure a narrow substrate scope, industrial scale-up and downstream purification complexity, the future of sustainable antibiotic production is in the strategic use of integrated, hybrid bio-chemical platforms.