Hide and seek: improved microbial strains vs. researchers

Developing novel microbial strains for direct industrial use presents several challenges. Firstly, it is of fundamental importance to identify the traits needing improvement and the right approach to generate new microorganisms. However many improvement methods result in a heterogeneous mixture of different genotypes amongst which the best candidates are hidden. It then becomes necessary to develop strategies that identify the desirable genotypes. The aim of such screening strategies is to identify the most promising strains for further characterization. Limited parameters are measured in the initial screening process for efficiency and high-throughput. However this can reduce the accuracy of the screening and if the resolution of the screening is too low, it increases the risk of carrying over sub-optimal strains into more in-depth analysis. Therefore the robustness of an initial screening exercise will significantly contribute to the efficiency of the overall improvement program.

We present here some experiences from the past decade of strain improvement and screening investigations. Thousands of novel wine yeast have been generated using a wide pool of techniques. Improved strains have been isolated under conditions mimicking wine fermentations. With the increased automation of laboratory instrumentation, researchers are now gaining the advantage over the microbes in the game of “hide and seek”. It is now possible to obtain a high level of characterization of hundreds of candidate strains from the first round of screening. From now on, it doesn’t matter how well the best candidate will hide: it will be revealed!