Harvey 1928 the Oxygen Consumption of Luminous Bacteria

8/13/2019 Harvey 1928 the Oxygen Consumption of Luminous Bacteria

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T H E O X Y G E N C O N S U M P T I O N O F LU M I N O U SB A C T E R I A .

B~ E. NEWTON HARVEY.From the Marine Biological Laboratory, Woods Hole, and the PhysiologicalLaboratory, Princeton University, Princeton.)

(Accepted for publication, January 18, 1928.)In a previous paper (1925) I ha ve published some f igures on the tot al

eff iciency of luminous bacte ria, regarde d as machi nes for l ight produc-t ion , which g ive the ra t io o f the l igh t emit ted to the to ta l en ergy inpu t ,expressed in the same energy un i ts (calo ries per second) . The en ergyinput was ca lcu la ted by a method of ind i rec t ca lo r imetry , f rom theoxygen consumpt ion of the bac ter ia . The oxygen consumed wouldl ibera te a def in i te amount o f hea t when used to burn the food of thebacter ia , a mix ture o f 40 per cen t pep tone and 60 per cen t g lycero l .

Since luminescence of the bac ter ia i s dependen t on d issolved oxygen ,the oxygen consumpt ion was measured by f ind ing the t ime necessaryfor an emuls ion of the bac ter ia in sea water to use up the d isso lvedoxygen to the po in t where the luminescence jus t beg ins to fade. Fro mthe so lub il i ty o f oxygen in sea water one can then ca lcu la te the oxygenconsumpt ion , p rov ided the b ac ter ia use equal amoun ts o f oxygen inequal t imes. Exper im ent shows tha t th e d imming po in t represen tsuti l ization of at least 99.5 per cent of the dissolved oxygen, a changefrom the dissolved oxygen in equilibrium with air (21 per cent) to thatin equ i l ib r ium with < 0 .5 per cen t oxygen , and tha t the luminescencein tensi ty o f the bac ter ia i s unaf fec ted by d i f feren t oxygen tensionsuntil th e ten sion falls to < 0.5 per cen t oxygen. 1 The oxygen con-sumpt ion is p robab ly a lso independent o f the oxygen tension un t i lapprox imate ly th is same value i s reached . The t ime for d imming foran undis tu rbed tu be of bac ter ia l emuls ion is p ropor t ional to the num -ber o f bac ter ia p resen t , and a lso approx imate ly p ropor tional to theoxygen tension wi th which the bac ter ia l emuls ion is b rought in to equ il i -

Unpublished experiments.69

The Journal of General Physiology

Published May 20, 1928


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brium, provided of course this is above the cri t ical value (0 .5 per centoxygen) . The me thod wou ld therefo re appear to be jus t if i ed , bu trequ i res conf i rmat ion , which i s the sub jec t o f th i s communica t ion .

The ac tua l f igures ob ta ined (Harve y , 1925) fo r oxygen consumpt ionof the bac ter i a in seven exper iment s a t t empera tu res rang ing f rom18 to 23C. v ari ed from 6.65 to 17.67 10 -15 rag. O3 per ba cte riu mper second, with an av erage of 11.84 X 10 -is rag. for an ave rage te m-pera tu r e o f 21 .5C. These va lues a re 10 per cen t too low, s ince itwas be l i eved , a t the t ime the exper iment s were made , tha t 2 per cen toxygen was the po in t a t which d imming occurred .

In o rder to check th i s method I have recen t ly made de terminat ionsof oxygen consumpt ion in the Thunberg-W in ters t e in resp i rometer asused by F enn ~1927) fo r exper iment s on oxygen consum pt ion bynerve . 2 The two cham bers were o f approx ima te ly 22 cc . capa c i tyand the capi l lary held 0 .403 gm. of me rcu ry in a length of 153 ram.Since the oxygen consumpt ion in th i s appara tus i s twice the vo lumemovement o f the cap iUary , each ram. movement o f the o i l d rop in thecap i l l a ry was equ iva len t to the consumpt ion o f 0 .000388 cc . 02 .The chambers con ta ined smal l vesse l s fo r the so lu t ion o f KOH toabsorb CO2. Two cc . o f bac ter i a l emuls ion in sea water was p laced i~one cham ber an d 2 cc. sea water w as p laced in the o ther , bo th in equ i lib -r ium wi th a i r. The whole appar a tus was immersed in a therm os ta to f runn ing sea wate r a t 21C. which changed l es s than 0 .01C. overa period o f 2 hours . The read ings o f the o il d rop le t mov emen ts p lo t t edagains t t ime are g iven in Fig . 1 , toge ther wi th th ree de terminat ions o fthe t ime fo r ano ther sam ple o f the same em uls ion o f luminous bac ter i ato d im, when s t and ing und i s tu rbed a t the same t empera tu re .

From Fig . 1 i t wi l l be seen tha t the ra t e o f oxygen consumpt ion i sp rac t i ca l ly indepe ndan t o f ra t e o f shak ing and tha t 2 cc. o f bac ter i a lemulsion used 0.0272 cc. 02 in 1950 seconds or 0 .0000139 cc. 02 persecond. One cc. of emulsion would use 0 .00000695 cc. per second.

Over the same t ime in terva l , a t 21C. , i t t ook 12 .5 minu tes o r 750seconds ( t ime ind ica ted by ar rows) fo r the luminescence o f a s imi larbacteria l emulsion to dim. At 21C. each cc. of sea wa ter wil l d is-

21 am greatly indebted to Dr. W. O. Fenn for the micro respirometer used inthese experiments and to M r. C. S. Shoup for growing the luminous bacteria andfor assistance with the experiments.



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so lve 0 .0052 cc . O~ ,Fox , 1909), a t l e as t 99 .5 p er c en t o f wh ic h is con-s u m e d w h e n d i m m i n g o c c u r s. H e n c e t h e b a c t e r i a in 1 c c . s e a w a t e rem uls ion used 0.0052 - 750 o r 0.00000693 cc . O~ per second , a va lu ei n p e r fe c t a g r e e m e n t w i t h t h e m i c r o r e s p ir o m e t e r . I c o n c l u d e t h a tt h e d i m m i n g m e t h o d g i v e s a v e r y g o o d in d e x o f t h e o x y g e n c o n s u m p -t i o n o f t h e b a c t e r i a .

I t i s i n te r e s t i n g to c o m p a r e t h e o x y g e n c o n s u m p t i o n o f l u m i n o u sb a c t e r i a w i t h t h a t o f o t h e r b a c t e ri a . O f t h e n u m e r o u s p a p e r s o n

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i/2 m. / 13 Ira ~ 5~.i o . o I . o o 1 1 . 7 o 1 1 0 1 1 . s o n o 1 I . o

Fig . 1 . Read ings o f index d rop scale o f micro resp irom eter in cm. p lo t ted againstt im e in m in u tes . B e lo w th e m ark , A ) , th e r e sp i ro m ete r w as sh ak en 9 8 t im es p e rminu te; above, B) , a t 120 times per minu te . The hor izon tal arrow l ines ind icatethe t imes fo r bacter ia l emulsions to use d isso lved oxygen , as determine d by thed lm m in g m e th o d .r e s p i r a t i o n o f b a c t e r i a c f . S t e p h e n s o n a n d W h e t h a m 1 92 4) , N o v ya n d S o n le 1 9 2 5) , B ro o k s 1 9 1 8 -1 92 2 ) , C a l l o w 1 92 4) a n d P t t t t e r1 9 2 4 ) ) , o n l y C a l l o w a n d P i i t t e r g i v e v a l u e s w h i c h c a n b e p r o p e r l y

c o m p a r e d , n a m e l y , o x y g e n c o n s u m p t i o n p e r w e i g h t o r v o l u m e o fb a c t e r i a. T h e l u m i n o u s b a c t e r i u m u s e d b y m e i n e ff i ci e nc y s t u d i e swa s a c y l i n d e r a v e ra g i n g 2 .2g l o n g b y 1 .1g i n d i a m e t e r w i t h ro u n d e de n d s . I t s s u r f a c e a r e a wa s 7 .6 ~ ~ a n d i t s v o l u m e 1 .6 9 5 ~ L W h e n



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47 O X Y G E N C O N S U M P T I O N O F L U M I N O U S B A C T E R L

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Harvey 1928 the Oxygen Consumption of Luminous Bacteria