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bioRxiv · 10.64898/2026.10.09.758012

Establishing genetic tractability in Jeongeupia sacculi HS-3: disruption of rpoS hinders biofilm formation

Beddingfield, Z.·Calimlim, I. K.·Zhang, C.·Hammer, B. K.
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Abstract

Jeongeupia sacculi (HS-3) is a novel {beta}-proteobacterium with a unique multicellular life cycle. The genetic tractability and mechanisms underlying differentiation are unknown. Here, we adapt a method of homologous recombination for genetic modification in HS-3 and generate a disruption mutant of rpoS, which encodes the alternative sigma factor{sigma} S commonly associated with general stress response or major behavioral switches. We then characterize phenotypes associated with rpoS disruption. Under low-nutrient conditions, rpoS disruption reduced Congo red binding, consistent with rpoS acting as a regulator of low-nutrient response by upregulating production of biofilm-associated materials. Surprisingly, rpoS disruption did not significantly alter survival in response to other stressors in general stress response assays tested. Our work establishes a method for genetic manipulation in HS-3 and enables future investigation into the life cycle of HS-3, including whether rpoS has a role in differentiation triggered by low-nutrient response.

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Beddingfield, Z., Calimlim, I. K., Zhang, C., Hammer, B. K.. 2026-10-10. Establishing genetic tractability in Jeongeupia sacculi HS-3: disruption of rpoS hinders biofilm formation. https://doi.org/10.64898/2026.10.09.758012

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