Aim

To determine whether PIXL can pick and plate a range of non-model organisms including a filamentous fungus and a range of actinobacteria.

Introduction

Microorganisms represent a major source of chemical diversity and the rate at which this huge resource can be screened is a limiting factor to the discovery of new compounds including chemical feedstocks, antibiotics, and other pharmaceuticals. New high-throughput screening processes must be developed in order to be able to efficiently exploit the vast microbial resources that are available.

PIXL, a precision colony-picking robot, addresses this bioprospecting challenge, by automating some of the culturing and downstream processing necessary for high-throughput experimentation with these organisms. PIXL has a proven transfer efficiency of >99% using common model organisms including E. coli and S. cerevisiae. To understand PIXL’s full capability the team at Isomerase, a Cambridge UK-based biological engineering company with an extensive proprietary collection of more than 20,000 strains, tried to ‘beat’ PIXL with a range of organisms, some of which they were confident would trip PIXL up. Here’s the background to the challenge.

One of PIXL’s core functions is to automatically detect colonies and then pick these to new plates for culturing or downstream analysis. For a colony-picking robot, colonies that have unusual colours or morphologies can pose a significant challenge for colony detection algorithms. Furthermore, if the physical properties of the cells prohibit adherence to the picking device, or the cells do not survive being picked, then it will prove difficult to effectively automate cell transfer.

Method

Isomerase were interested to understand whether PIXL could pick colonies of species that exhibited atypical phenotypes. This included the dark brown filamentous fungus Glarea lozoyensis and a wide range of filamentous bacteria from around the world, including Kitasatospora putterlickiae, Streptomyces avermitilis and Streptomyces venezuelae. The organisms chosen were not only different colours but also exhibited different colony morphology, from dry and powdery, to extremely tenacious. How did PIXL perform against these challenges?

Fig 1. Collection of Isomerase source plates picked using PIXL.

Results

This is what Dr Martin Sim, senior scientist at Isomerase had to say about PIXL’s performance:

“I’m happy to say that every strain we picked and replica plated onto the solid agar in the 96 well plates grew, and after three weeks in the incubator no plate has shown evidence of contamination”

The advantage of being able to automatically pick and plate colonies is clear and PIXL’s success demonstrates how sophisticated this colony-picking robot is. But what is it like ‘in the field’? Can it handle uneven agar surfaces? Sophisticated can sometimes mean complicated, so is PIXL difficult to work with? Here is Martin again discussing how he and his team found working with PIXL:

“Everyone was very impressed with the machine, especially its ease of use and the friendly software user interface, the polymer picking system, and of course how it was accurately handling uneven agar surfaces, and working with our unusual colony morphologies.”

Conclusion

PIXL successfully detected and picked a variety of fascinating organisms chosen by Isomerase. PIXL has already been shown to detect and pick model organisms such as S. cerevisiae (yeast), E. coli (gram-negative bacteria) and C. reinhardtii (algae). The findings reported here demonstrate that PIXL is also capable of working with non-model organisms that exhibit atypical and challenging phenotypes. In light of this, PIXL could be readily utilised in bioprospecting applications, as well as in other fields that use non-model organisms. 

Glarea lozoyensis

Kitasatospora putterlickiae

Streptomyces avermitilis & streptomyces venezuelae

Do you want to reliably pick non-model organisms?

Get in touch with our product experts to learn how PIXL can automate your workflow.






    Sign up to our newsletter






    Related Articles

    Automating MALDI-TOF sample preparation protocols to facilitate bacterial identification

    PIXL Efficiency Report: Agar-Agar

    Automatic zone of inhibition detection and analysis with PIXL