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VERSION:2.0
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METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20260815T000501Z
LAST-MODIFIED:20191029T133054Z
DTSTART:20191029T193000Z
DTEND:20191029T203000Z
UID:event2167@bu.edu
URL:http://physics.bu.edu/internal/events/show/2167
SUMMARY:Flower-like patterns in multi-strain bacterial colonies
DESCRIPTION:Featuring Lev Tsimring\, BioCircuits Institute\, University of 
	California\, San Diego\nPoster: http://physics.bu.edu/internal//files/downl
	oad/Tsimring-poster.pdf\n\nPart of the Physics Department Colloquia Series.
	\n\nDiverse interactions among species within bacterial colonies often lead
	 to intricate spatiotemporal dynamics. The spatial structure can determine 
	the growth and survival of different species\, but the mechanisms driving f
	ormation of these structures are not fully understood. Here\, we describe t
	he emergence of complex structures in a colony grown from a mixture of moti
	le and non-motile strains of bacteria on a semi-solid agar surface. Time-la
	pse imaging shows that non-motile bacteria "hitchhike" with the motile bact
	eria as the latter grow and expand. The non-motile bacteria accumulate at t
	he moving colony boundary and trigger a mechanical instability of the colon
	y boundary that leaves behind striking flower-like patterns. The mechanism 
	of the front instability governing this pattern formation can be qualitativ
	ely elucidated by a mathematical model describing frictional interface moti
	on where friction depends on the local concentration of the non-motile stra
	in at the interface. We also developed a two-dimensional phase-field model 
	that explicitly accounts for the interplay between mechanical stress from t
	he motile species and effective friction provided by the non-motile species
	 and reproduces the observed phenomenology. Our findings highlight the impo
	rtance of mechanical interactions in shaping the spatial structure of multi
	-strain biofilms.
LOCATION:SCI 109\, 590 Commonwealth Avenue\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
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