Microbial marine natural products hold significant potential for the discovery of new bioactive therapeutics such as antibiotics. Unfortunately, this discovery is hindered by the inability to culture the majority of microbes using traditional laboratory approaches. While many new methods have been developed to increase cultivability, a high‐throughput in situ incubation chamber capable of simultaneously isolating individual microbes while allowing cellular communication has not previously been reported. Development of such a device would expedite the discovery of new microbial taxa and, thus, facilitate access to their associated natural products. In this study, this concept is achieved by the development of a new device termed by the authors as the microbe domestication (MD) Pod. The MD Pod enables single‐cell cultivation by isolating marine bacterial cells in agarose microbeads produced using microfluidics, while allowing potential transmission of chemical signals between cells during in situ incubation in a chamber, or “Pod,” that is deployed in the environment. The design of the MD Pod was optimized to ensure the use of biocompatible materials, allow for simple assembly in a field setting, and maintain sterility throughout incubation. The encapsulation process was designed to ensure that the viability of marine sediment bacteria was not adversely impacted by the encapsulation process. The process was validated using representative bacteria isolated from temperate marine sediment samples: Marinomonas polaris, Psychrobacter aquimaris, and Bacillus licheniformis. The overall process appeared to promote metabolic activity of most representative species. Thus, microfluidic encapsulation of marine bacteria and subsequent in situ incubation in the MD Pod is expected to accelerate marine natural products discovery by increasing the cultivability of marine bacteria.

The cover image is based on the Article Development of a microbe domestication pod (MD Pod) for in situ cultivation of micro‐encapsulated marine bacteria by Tartela Alkayyali et al., https://doi.org/10.1002/bit.27633.

Through the hyphenation of microfabrication, microfluidics and microbiology, we report the development of a μMicrobial-Domestication Pod (μMD Pod) for in situ cultivation of bacteria.

Marine natural products produced by microbes represent an indispensable resource for various biotechnological applications, including use as medicines, dietary supplements, personal care products and diagnostic agents. However, the discovery of novel natural products is hindered by the fact that only approximately 1% of microbes are currently culturable under traditional laboratory practices as described by the Great Plate Count Anomaly. While various advancements have improved cultivability, the ability to culture "unculturable" microbes remains limiting as existing techniques do not facilitate interspecies cellular communication while maintaining high throughput cultivation. To overcome these limitations, we developed a new in-situ microbial growth chamber, termed the microbial domestication pod (MD Pod). The MD Pod uses microfluidics to encapsulate bacteria within agarose microbeads resulting in high-throughput cultivation and isolation while allowing cellular communication and transmission of chemical signals. To assess the feasibility of this concept, three marine species were encapsulated and their subsequent viability was assessed. Additionally, the ideal encapsulating temperature and matrix were determined. Prior to use, the MD Pod was subjected to biocompatibility and contamination testing. The viability and diversity of microbes cultured using the MD Pod will be compared to those cultured using traditional plating methods. It is expected that the use of the MD Pod will result in the culture of a greater diversity of microbes, therefore facilitating the discovery of novel marine natural products.