NOTES

Can. J. Microbiol. Downloaded from www.nrcresearchpress.com by UNIVERSITY OF ARIZONA LIBRARY on 01/22/13 For personal use only.

E v i d e n c e o f a competitive h i e r a r c h y among c o p r o p h i l o u s f u n g a l p o p u l a t i o n s 1 D O N A L T. D WICKLOW' Del~or.f~tic,rrr c!f'LiJi,Scierrc.i,.s. Urril.c,rsify c:f Pifr.sl1rrrg11,P i f f . ~ l ~ r r r PA, ~ g l ~U.S.A. . 15260 AND

B. J . HIRSCHFIELD Berretlrrrt~S(.lrool oj'Mcelic~olT t ~ c ~ h ~ r o lTo lg~~eWesfc,t.rr . Pctrtr.sylctr~rioHospiftrl. P i ~ ~ . ~ h r r r PA, ~ g / rU.S.A. , 15223 Accepted April 2. 1979 W I C K L O WD.. T . , and B. J . HIIISCHFIELD. 1979. Evidence of a competitive hiemi-chy among coprophilous fungal populations. Can. J . Microbiol. 25: 855-858. Evidence is presented that inte~ferencecompetition may be important in later stages of fungal colonization of cattle feces from 21 semiarid grassltind in Colo~.;~do. Cultural antagonism was examined ;imong fungal isolates representing e:t~.lysporulating colonists (A.sc.oho1rr.sjir~:firr~o(~c~~r.s and Strc~c~ol~olrrs f~~rrtrc~trfrr.s), later sporulating colonists (loc/opI~otrrrsc.trrrrc,rr.s. Cor~ioc~lroeftr tlist~o.s/~ortr. Hy11oi.opr.tr ~t~c~rcltrr.itr, and Pot~orrioprrtic~ftrfo), and one early successional species that is able to persist (sporulate) through I:itcr stages (Poclo.\poro t1rc.ipior.c.). Pororrirr prrtrt.fcrftr. 21 compa~':itively slower-gl'owing and Inter-appearing colonist (18- to 54-month-old fecal pats). is uniformly antagonistic to :ill of seven earlier-appearing and co-occurring fungal species. Antibiosis is believed to account for the observed >intagonism. The authors suggest that the evolutionary product of interference competition among coprophilous fungal populations may be ;I pattern of ccimpetitivc hierarchy in which ccrtain slowel.-growing, later.-successional specics can limit thc ~.eprIUG\VU. F. E. 0.. and J . W I ~ B S T I 1970t1. ~ I I . Ant;tgonisrn hierarchy in post-fire ascomycctcs. Mycologia. 71: 47-54. hctwcen C'opri~rr~.~ / r r p t o ~ r r ~ ~and r r s other copsophilous fungi. WICKL.O\V. D. T.. ilnd D. M A I . I L ~ C 1971. H . Studies in Ihc genus T~.ans.BI-.Mycol. Soc. 54: 181-204. T/lc,/r/~o/rr.s.T e n i p e ~ . : ~ t ~optima ~re for. gsowth and ascocnsp -197011. Hyphal intcrfel-encc in ;I r;inge of copl-ophilous fi~ngi.Trans. BI.. Mycol. Soc. 54: 205-210. development. Mycologiir. 63: 1 18-13 1. . l o ~ s s oI..~ .F.. and E. A. C U R L 1971. . Methods fo~.~.ese;~~.ch on WI(.KLOW. D. T . . ;~nclV. Moo~u:. 1974. Effect of incubation tcmpe~.atuseon the cop~.ophilousfungal succession. Trans. the ecology of soil-bosne pathogens. Burgess Publishing Co.. Br. Mycol. Soc. 62: 41 1-415. Minncapolis. OLIVI:.1.. S. 1956. Genetics of S o r t / t ~ ~ . i o , / i ~ ~ ~I . i Ascospv~-c (~oIt~. Z-\K.J . C.. and D. T . W I C K L O W 1978. . Response ofc;~~.honicolous nscomycetes to aer;ltcd steam teniper:rtures and trcatcolor rnut;lnts. Am. J . Bot. 43: 97-107. nient interv;rls. Can. .I. Bi)t. 56: 13 13-23 18. PAIIK.D. 1967. The impel-lance of antibiotics and inhibiting A. Burges and F. Raw. substances. 111Soil biology. t~tlit(,rll~y Ack~demicPl.ess, New Yosk. pp. 435-447.

Method for the rapid screening of cellulolytic streptomycetes and their mutants C ' P I I ~ I dc, , ~ I . ( Y ~ I I ~ ,(,II I . ~l ~ It I~~~, ~ t ( ; r i o111.stit11t l o g i ~ ~A, r ~ ) ~ t ~ ~ ~ t l - F ~ . t UII~L.OI..S~~C; ~ p [ ) i c , r , (//IQIIL;/I~,~,, C.P. 100. Villc tlr L.ocol (QII~;.), Co~lc~c/o H7N 4Z.7 Accepted April 17. 1979 Method for the sapid screening of D,\ICKI:AUL.I--SYLVES.I.III:. N., and D. K L U L P F E L1979. . cellulolytic stseptomycetes and their niut;ints. Can. J . Microbiol. 25: 858-860. A method for the rapid scl'cening of cellulolytic strcptomycetes and thcir mutants is repol-ted. The lechnique consists of a plate ossk~yon media containing filter paper libres as cellulose substsate. The cellulolytic ;~ctivityis detected and me;~hu~-cd by the formation of cleasing zones al-ound the streptornycete colonies. The sensitivity of the method is incre:rscd consideritbly by subjecting the plates to an addition~ilincubation period at 43°C in the presence of a buffer at pH 5.3. By replicating these colonies on other Petri plates containing the appropriate media. it is possible to assess ~ritpidly.not only the degl-ee of catabolic repression of the cellul:rse pl.oduction by glucose. hut also, in >I semiqu;tntitative way, the amount ofenzymes produced. I)AI~;NI~AUL~T-S\.LVLIS~~RL. N.. et D. KI.UI;PFEI.. 1979. Method for the I-apid scseening of ce[Ii~lolyticstseptomycetes and their mutants. Can. J . Microbiol. 25: 858-860. Une methode de depistage rapide pour des stl-eptomycittes ccllulolytiques et leurs mutants est decl-itc. 1n . technique est basee sur I'emploi de fibres d e papierfiltre cornme source de cellulose et incorposees d ; ~ n sun milieu solide. L'activite cellulolytique se manifeste par la formation d'une zone tl'eclaircisscnient a ~ ~ t o de u r la colonic de streptomyckte. 1.a sensihilite de In methode est :rugmentie considel.nblenient en traitant les plaques par une incubation ;idditionnelle ;I 43°C en presence d'un tampon. pH 5.3. Ell-replication de ces colonies sur milieu solideapproprie. i l est possible de vesifier sapidemcnt non seulement Is degre tlc I;) repression c:rt;rbolique des enzymes pal- le glucose. mnis :u~ssidc dktel-miner tie k r p n semiqunntitarivc leur production.

In recent years. considerable efforts have been made to improve the conversion of cellulose to glucose by either chemical or enzymatic processes. A cost analysis of the biochemical method showed that the production of cellulolytic enzymes represents not less than 60% of the total expenditure (Wilke or o l . 1976). It is therefore obvious that economical la-ge-scale p~.oductionof the cellulase

complex is of primary importance. Studies on the genetic improvement of microbial strain by mutntion and selection techniques have been restricted I . ( > P S O ~QM6 isolated by mainly to TI.~'(./IO~CI.I?IN Mandels and Reese (1957) at the U.S. Army Natick Research and Development Labor-atories. Mandels or (11.(1971) succeeded in obtaining a mutant sti'nin with a three- to foul--fold increase i n enzyme pro-

0008-4 l66/79/070858-03$0 I .00/0 @ 1979 National Ilc\carch Council of CanadaIConsc~lnational dc recherche\ du Canada

Evidence of a competitive hierarchy among coprophilous fungal populations.

NOTES Can. J. Microbiol. Downloaded from www.nrcresearchpress.com by UNIVERSITY OF ARIZONA LIBRARY on 01/22/13 For personal use only. E v i d e n c...
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