Table 1.

Strains used in this study

Isolate	Species	Location & relevant information
Dictyostelids:
Dd-AX3	D. discoideum	Little Butts Gap, NC, USA. Axenic derivative of NC-4 (Raper and Rahn, 1984), called A3 in original citation (Loomis, 1971). See also (http://dictybase.org). axenic strains history.
Dg-WS-142	D. giganteum	Madison, WI, USA (1954). Previously described (Raper and Rahn, 1984; Weber and Raper, 1971). Lyophilized 8/16/71.
Da-WS-309	D. aureostipes	Dayton, OH, USA (1956). Isolated from the National Cash Register Woods. Deciduous woods with poplar, oak, maple and cherry. Lyophilized 12/22/70.
Dd-WS-647	D. discoideum	St. Tammany Parish, LA, USA (1976). Collected by Ann C. Worley from soil and highly decomposed leaf litter, approx. 20 yards from a creek; Honey Island Swamp near Pearl River. Bottom lands covered w/tupelo & cyprus. Many hardwood shrubs and small trees. Lyophilized 8/29/79.
Pp-ES	P. pallidum	San Salvador, El Salvador (Raper and Rahn, 1984). Lyophilized 4/57.
Bacteria:
S17.1	E. coli	Chromosomally modified donor used for conjugal transfer of plasmid DNA (Simon et al., 1983).
M5al	K. oxytoca	Suspected biofilm-forming strain based on studies of other K. oxytoca strains (Bao et al., 2013; Hamilton and Wilson, 1955; Pengra and Wilson, 1958; Yoch and Pengra, 1966). Biofilm formation by M5al established – This study.
KOF001	K. oxytoca	M5al harboring plasmid pFL300 and expressing d- Tomato red fluorescent protein. This study.
PAO1	P. aeruginosa	Biofilm-forming pathogen of humans (Banin et al., 2005; Diggle et al., 2006).
207.2	P. syringae	Biofilm-forming pathogen of beans. Unpublished. Provided by Dr. Patricia McManus, Department of Plant Pathology, University of Wisconsin-Madison.
Ea 1189	E. amylovora	Biofilm-forming pathogen of rosaceous species such as apple and pear (Burse et al., 2004; Koczan et al., 2009).
Ea 1189 Δams	E. amylovora	Biofilm-deficient (in vitro and in planta) nonpathogenic mutant of strain Ea 1189 (Koczan et al., 2009; Zhao et al., 2009).