Swiss scholars propose a new method to rapidly cultivate bacterial variants

Scientists ingeniously use the "natural selection method" to transform bacteria into efficient cellulose "production factories".

On August 14, 2024, according to the official website of the Swiss Federal Institute of Technology in Zurich, the research team of the university successfully proposed a brand-new method for the production of cellulose using bacteria. For a long time, scientists have been committed to transforming microorganisms into living "production factories" to accelerate the production of a large number of required products. This new method follows the evolutionary mechanism of natural selection, aiming to improve the efficiency of bacterial cellulose production.

Although Acetobacter K. sucrofermentans can produce high-purity cellulose, it grows slowly and has limited output in the wild-type state. Due to the huge demand for cellulose materials in fields such as biomedical applications, packaging materials, and textiles, increasing its output is extremely urgent.

The research team first irradiated the bacterial cells with ultraviolet light to randomly damage their DNA sites, and then placed the bacteria in a dark room to induce mutations. Later, a micro-instrument was used to encapsulate each bacterial cell in a small drop of nutrient solution, allowing the cells to produce cellulose within a specific time. After the incubation period ended, fluorescence microscopy was used for ***ysis and with the help of a newly developed fully automatic sorting system, bacterial cells capable of producing a large amount of cellulose were rapidly screened out. Several variants of Acetobacter successfully cultivated in the end had a cellulose output that was 70% higher than that of the original strain. The cellulose output of the four selected strains was 50% - 70% higher than that of the wild type.

The evolved Acetobacter cells can grow at specific positions in glass bottles and produce cellulose mats. The weight and thickness of the cellulose mats produced by the evolved variants are almost twice that of the wild type. The team's next plan is to test this new microorganism under actual industrial conditions. As cellulose is a polysaccharide widely distributed and abundant in nature, this time the team imitated the "natural selection method" and with the help of the new sorting system to assist the "evolution" of Acetobacter cells. Whether it can increase production and income in industrial production is highly anticipated.