Tal­mu­dic Ques­tion #41

CONTACT!
In or­der to eat one has to touch! There has to be sur­face to sur­face con­tact in or­der to en­gulf! Thus, we could gen­er­al­ize and say that all preda­tors have to con­tact their prey! This is one of the key com­mon mech­a­nisms. The claw and teeth of the lion has to con­tact the an­te­lope, just like lambda to bac­te­r­ial OMP's, fun­gal hy­phae to cell sur­face re­cep­tors, ad in­fini­tum...
How­ever, on might en­vi­sion death with­out di­rect en­gage­ment – such as by long dis­tance tox­ins – and then ab­sorbance of the nu­tri­ents re­leased. This lat­ter mat­ter has two philo­soph­i­cal prob­lems in re­gard to the Tal­mu­dic ques­tion asked. First, long dis­tance killing by tox­ins does not nec­es­sar­ily mean ab­sorp­tion of nu­tri­ent. Thus its a "preda­tor in trans". Sec­ondly, even a toxin has to make con­tact even­tu­ally, thus not elim­i­nat­ing the com­mon mech­a­nism of con­tact – in its most or­tho­dox un­der­stand­ing.

The real is­sue, over and over, is self ver­sus non­self. Look at the is­sue of "cheaters" in Greg Velicer's work with myxobac­ters.
Trav­isano, M. and G.J. Velicer (2004). "Strate­gies of mi­cro­bial cheater con­trol." Trends Mi­cro­biol. 12: 72 — 78.
"Cheat­ing" ap­plies to all kind of mi­crobe-mi­crobe in­ter­ac­tions, af­ter all.
I haven't ac­tu­ally sat down and done the ex­per­i­ment, but does a given strain of Bdellovib­rio "pre­fer" other bac­te­ria to its sibs? In­ter­est­ing ques­tion, but it re­mains im­por­tant to keep in mind that what we "set up" in the lab­o­ra­tory does not re­flect the nat­ural sit­u­a­tion very closely. It re­minds me very much of my old sys­tem of Sinorhi­zo­bium meliloti and alfalfa—mutant bac­te­ria added to bare roots on agar, and draw­ing con­clu­sions about nodu­la­tion ef­fects. The lab found out a great deal, but the in­ter­play of the di­verse rhi­zos­phere mi­cro­biota is a tough nut to crack. Hence my think­ing about "cheaters."
The "dead hand" of Dar­win is ever with us. And to bor­row from J.B.S. Hal­dane, I don't be­lieve that the mi­cro­bial world is merely stranger than we imag­ine. It is stranger than we can imag­ine.
I par­tic­u­larly ap­pre­ci­ate see­ing ref­er­ences here to "old" pa­pers that genome-philes may have missed. The most im­por­tant in­stru­ment in a lab­o­ra­tory is not a fancy qPCR ther­mo­cy­cler, but eyes and brain. This pa­per re­minds me of that prin­ci­ple:
Shu­man, H.A. (2003). "Just tooth­picks and logic: how some labs suc­ceed at solv­ing com­plex prob­lems." J. Bac­te­riol. 185: 387 — 390 (with three cheers for Jon Beck­with, who, like Elio and sev­eral other posters here, has for­got­ten more than I will ever know about mi­cro­bial ge­net­ics).
Oh...and happy Thanks­giv­ing to all mi­crophiles, near and far.
Elio, I am va­ca­tion­ing with my fam­ily in Long Beach, Wash­ing­ton, and thought of you when I saw not one but two "mush­room hunt­ing" guides in the gift shop of our ho­tel. Well, I am ac­tu­ally grad­ing pa­pers, but you know what I mean.