Systematic evaluation of isolation processes of microorganisms using spatial statistics.

The evaluation of inoculation processes of microorganisms by robotic systems as well as by lab-technicians is compensable and can be missing consistency as human judgment will depend on the individual and may therefore be biased and less effective than models and algorithms evaluating spatial patterns. To address this problem, nearest neighbor analysis was used to investigate if it could be utilized as a method to evaluate isolation processes. The nearest neighbor analysis results in a comparable numeric value on the isolation process, which can be used to assess results of different inoculation processes. In this article, images of Petri dishes and simulated plates are used to investigate the effectiveness of nearest neighbor analysis, which is a method within spatial statistics. This analysis is applied to spatial data created by applying computer vision to localize the colonies on the plates. When evaluating plates made with the streaking technique method, it was found to be ineffective as the dense parts of the distribution resulted in the computer vision being unable to locate all of the colonies. Therefore, the nearest neighbor analysis is not suitable to evaluate streaking plates and other methods to evaluate such plates should be developed. However, when evaluating Petri dishes where the spread plating technique had been applied, it was found that nearest neighbor analysis can be a useful way to systematically evaluate isolation processes.

An open-source robotic platform that enables automated monitoring of replicate biofilm cultivations using optical coherence tomography.

The paper introduces a fully automated cultivation and monitoring tool to study biofilm development in replicate experiments operated in parallel. To gain a fundamental understanding of the relation between cultivation conditions and biofilm characteristics (e.g., structural, mechanical) a monitoring setup allowing for the standardization of methods is required. Optical coherence tomography (OCT) is an imaging modality ideal for biofilms since it allows for the monitoring of structure in real time. By integrating an OCT device into the open-source robotic platform EvoBot, a fully automated monitoring platform for investigating biofilm development in several flow cells at once was realized. Different positioning scenarios were tested and revealed that the positioning accuracy is within the optical resolution of the OCT. On that account, a reliable and accurate monitoring of biofilm development by means of OCT has become possible. With this robotic platform, reproducible biofilm experiments including a statistical analysis are achievable with only a small investment of operator time. Furthermore, a number of structural parameters calculated within this study confirmed the necessity to perform replicate biofilm cultivations.

Death and Progress: How Evolvability is Influenced by Intrinsic Mortality.

Many factors influence the evolvability of populations, and this article illustrates how intrinsic mortality (death induced through internal factors) in an evolving population contributes favorably to evolvability on a fixed deceptive fitness landscape. We test for evolvability using the hierarchical if-and-only-if (h-iff) function as a deceptive fitness landscape together with a steady state genetic algorithm (SSGA) with a variable mutation rate and indiscriminate intrinsic mortality rate. The mutation rate and the intrinsic mortality rate display a relationship for finding the global maximum. This relationship was also found when implementing the same deceptive fitness landscape in a spatial model consisting of an evolving population. We also compared the performance of the optimal mutation and mortality rate with a state-of-the-art evolutionary algorithm called age-fitness Pareto optimization (AFPO) and show how the two approaches traverse the h-iff landscape differently. Our results indicate that the intrinsic mortality rate and mutation rate induce random genetic drift that allows a population to efficiently traverse a deceptive fitness landscape. This article gives an overview of how intrinsic mortality influences the evolvability of a population. It thereby supports the premise that programmed death of individuals could have a beneficial effect on the evolvability of the entire population.

Constructing living buildings: a review of relevant technologies for a novel application of biohybrid robotics.

Biohybrid robotics takes an engineering approach to the expansion and exploitation of biological behaviours for application to automated tasks. Here, we identify the construction of living buildings and infrastructure as a high-potential application domain for biohybrid robotics, and review technological advances relevant to its future development. Construction, civil infrastructure maintenance and building occupancy in the last decades have comprised a major portion of economic production, energy consumption and carbon emissions. Integrating biological organisms into automated construction tasks and permanent building components therefore has high potential for impact. Live materials can provide several advantages over standard synthetic construction materials, including self-repair of damage, increase rather than degradation of structural performance over time, resilience to corrosive environments, support of biodiversity, and mitigation of urban heat islands. Here, we review relevant technologies, which are currently disparate. They span robotics, self-organizing systems, artificial life, construction automation, structural engineering, architecture, bioengineering, biomaterials, and molecular and cellular biology. In these disciplines, developments relevant to biohybrid construction and living buildings are in the early stages, and typically are not exchanged between disciplines. We, therefore, consider this review useful to the future development of biohybrid engineering for this highly interdisciplinary application.

New Capabilities of EvoBot: A Modular, Open-Source Liquid-Handling Robot.

We introduce a robot developed to perform feedback-based experiments, such as droplet experiments, a common type of experiments in artificial chemical life research. These experiments are particularly well suited for automation because they often stretch over long periods of time, possibly hours, and often require that the human takes action in response to observed events such as changes in droplet size, count, shape, or clustering or declustering of multiple droplets. Our robot is designed to monitor long-term experiments and, based on the feedback from the experiment, interact with it. The combination of precise automation, accurately collected experiment data, and integrated analysis and modeling software makes real-time interaction with the experiment feasible, as opposed to traditional offline processing of experiments. Last but not least, we believe the low cost of our platform can promote artificial life research. Furthermore, prevalently, findings from an experiment will inspire redesign for novel experiments. In addition, the robot's open-source software enables easy modification of experiments. We will cover two case studies for application of our robot in feedback-based experiments and demonstrate how our robot can not only automate these experiments, collect data, and interact with the experiments intelligently but also enable chemists to perform formerly infeasible experiments.

Creating and maintaining chemical artificial life by robotic symbiosis.

We present a robotic platform based on the open source RepRap 3D printer that can print and maintain chemical artificial life in the form of a dynamic, chemical droplet. The robot uses computer vision, a self-organizing map, and a learning program to automatically categorize the behavior of the droplet that it creates. The robot can then use this categorization to autonomously detect the current state of the droplet and respond. The robot is programmed to visually track the droplet and either inject more chemical fuel to sustain a motile state or introduce a new chemical component that results in a state change (e.g., division). Coupling inexpensive open source hardware with sensing and feedback allows for replicable real-time manipulation and monitoring of nonequilibrium systems that would be otherwise tedious, expensive, and error-prone. This system is a first step towards the practical confluence of chemical, artificial intelligence, and robotic approaches to artificial life.