Biological process engineering by Pseudomonas sp. ABC1: a discovery-stage ecological chassis for open bioproduction

Introduction Conventional industrial biotechnology remains constrained by contamination control requirements and energy-intensive biomass separation. Next-generation industrial biotechnology (NGIB) seeks microbial platforms that retain useful production phenotypes under open cultivation while enabling simpler process configurations. Here, we evaluated Pseudomonas sp. ABC1, a fluorescent siderophore-producing bacterium, as a discovery-stage ecological chassis for open bioproduction. Methods Seven-day open, non-sterile static cultivation was integrated with community profiling, microscopy, elemental analysis, peptidomics, proteomics, and comparative genomics. Results ABC1 formed a cohesive floating pellicle associated with a non-axenic bacterial consortium that included Pseudomonas, Delftia, Flavobacterium, Acidovorax , and additional environmental genera. Genome-informed reconstruction of representative community members indicated distributed capacities for iron acquisition, oxidative-stress protection, adhesion, nutrient acquisition, and extracellular-matrix metabolism. LC-MS/MS recovered 1,518 de novo peptide sequences, including 1,478 non-redundant sequences, with recurrent N-hydroxy-cyclo-ornithine derivatives and other modified peptide forms. These signatures are consistent with metallophore-associated biosynthesis predicted from the extensive iron-acquisition machinery previously described for ABC1. Comparative genomics further showed that ABC1 lacks complete canonical Pel, Psl, alginate, and PNAG systems but contains two extended loci encoding complementary functions for non-canonical extracellular-polysaccharide assembly, including rfbDCAB precursor synthesis, multiple glycosyltransferases, candidate Wzx/Wzy-like proteins, and export-associated components. ABC1 also encodes an expanded nutrient-acquisition architecture and 29 cyclic-di-GMP-associated proteins. Calcium-enriched pellicle microdomains and extracellular adhesive proteins provide additional candidate structural features, although mineral identity and polymer composition remain unresolved. Discussion Collectively, these data support ABC1 as a promising discovery-stage system in which ecological selection, extracellular-matrix organization, and biosynthetic diversification can be investigated under open cultivation. Quantitative validation of productivity, contamination resistance, biomass-recovery performance, safety, and scale-up remains necessary before industrial advantage can be established.