Zbl. Bakt. Abt. II, Bd. 130, S. 486-490 (1975)

[Chemical Laboratories, University of Allahabad, Allahabad, U.P., India]

Activatory Effect of some Rare Earths on Microbial Nitrogen Transformations Krishna Bahadur and Parveen Tripathi With 3 figures

Summary Lanthanum sulphate induced enhancement of nitrogen fixation by bacteria. The carbon con· sumption rate was similarly increased. In three microbial specimen the rate of mg. nitrogen fixed per g. carbon consumed was greater in presence of the metal ion, while in one case the rate decreased appreciably. Praseodymium sulphate inhibited the nitrogen fixation values in one sample, while three spe· cimen showed activation. Appreciable increase in respiratory rate was perceived in all the cases studied. Inhibition was apparent in data of nitrogen fixed/carbon consumed. Lanthanum ions clearly acted as promotor;; in nitrogen fixing bacteria.

Zusammenfassung Lanthansulfat bewirkte eine Zunahme der Stickstoffbindung durch Bakterien, auch der Kohlenstoffverbrauch nahm in ahnlicher Weise zu. Bei drei Isolaten N-bindender Mikroorganismen war die Menge des fixierten Stickstoffs (mg) pro Gramm verbrauchten Kohlenstoffs in Anwesenheit von Metallionen hoher, wahrend in einem anderen FaIle der Wert merklich verringert war_ Praseodymsulfat hemmte die Stickstoffixierung in einem Isolat, wahrend drei andere Isolate Aktivierung zeigten. Eine bemerkenswerte Zunahme der Atmung wurde in allen Fallen beobachtet. Eine Hemmung war erkennbar im Verhaltnis Stickstoffixierung: Kohlenstoffverbrauch. Lanthanonen wirkten deutlich als Forderer stickstoffbindender Bakterien.

Metal ions show diverse effects on living systems and are present in the soil in varying quantities. Bacteria exhibit different physiological activities in the presence of different metals. NICHOLAS (1) affirmed that trace metals are associated with a number of flavoproteins. WILLIAMS (2) published a review on the effect of heavy metallic ions on biological systems. HIRAYAMA (3) studied the role of transition metal complexes in nitrogen fixation. MALSTROM and ROSENBERG (4) have reaffirmed the participation of metal ions, both as integral parts of purified crystalline enzymes and as activators of enzymic reactions. KRASIL'NIKOV (5) observed accumulation of radium, thorium, and uranium by Azotobacter. Lanthanides are present in soil in traces and their universal distribution is well known. For the present article, their effect in nitrogen fixation has been studied. Four specimen of nitrogen-fixing bacteria were isolated from soil samples from Allahabad district. For convenience these individual organit'ms have been designated

Activatory Effect of some Rat;e Earths on Microbial Nitrogen Transformations

487

PI' P 2 , P 3 , and P 4• For the present article the effect of varying concentrations of lanthanum sulphate and praseodymium sulphate in the culture media on the nitrogenfixing activity was exhaustively studied.

Materials and Methodsl ) 2) Mineral nutrient solution consisted of: Solution A: 100 mg. sodium chloride, 10 mg. molybdic acid, and 1 mg. ferrous sulphate, dis· solved in 100 mI. double·distilled water. The pH recorded was 5.8 and was adjusted to 7.5, using 0.15 N phosphate buffer in requisite quantity. Made up the volume to 500 mI. with double·distilled water and autoclaved for thirty minutes at fifteen pounds per square inch pressure. Solution B: 200 mg. magnesium sulphate and 100 mg. calcium chloride were dissolved in 250 mI. double distilled mater. Autoclaved fur thirty minutes at 15 p. s . i. Solution C: 15 g. of mannitol was dissolved in varying amounts of 400 ,uM metal ion solution, requisite amounts of double·distill ed water was added (Table 1) till the volume was 250 mI., auto· c1aved for 30 minutes at 15 p. s. i. Table S. No.

mi. of 400,uM. metal ion solution

m!. of double· distilled water

Resultant molarity in ,uM. of metal ions in culture media

l. 2. 3. 4. 5.

0.0 62.5 125.0 187.5 250.0

250.0 187.5 125.5 62.5 0.0

0 25 50 75 100

Solution A, B, and C were mixed in the following proportion under sterilized conditions: A:B:C=2:1:1 Inoculated by BURDON'S (6) method and used four days old culture. Incubated for fifteen days at 32 OF and then estimated the amounts of carbon and nitrogen in the sample.

Results and Discussion The above data indicate that fixation of nitrogen was variously affected by the two metal ions. In the case of PI bacteria the amount of nitrogen fixed in the presence of lanthanum sulphate, increased regularly, reaching the peak amount at 100 ,uM. The maximum concentration. Carbon consumption was found to increase with the increase in concentration of lanthanum ions, indicating enhancement of respiratory rate. Presence of praseodymium ions in the medium showed an inhibitory effect in nitrogen fixation and a high carbon consumption rate. Thus, data of mg. of nitrogen, fixed per g. carbon consumed, showed drastic lowering of the values as compared to those obtained at 0 ,uM. P2 microbe in media containing lanthanum ions resulted in slight lowering of the nitrogen fixed at 25,uM., whereafter the rate of fixation increased greatly. Sporadic increases and decreases in carbon consumption were observed, thus, the respiratory rate was neither uniformly increasing nor decreasing. Nitrogen fixation data of P 2 in presence of praseodymium ions in the culture solution showed a uniform increase up to 75,uM., where after at 100,uM. a slight decrease was observed. Carbon con1) Results were statistically calculated. 2) All chemicals were of Anala. R grade.

488

K. BAHADUR and P. TRIPATHI

Table 2. Study of cultures inoculated in culture media containing lanthanum and praseodymium ions S. No.

Bacterial Molarity of metal ion sample inpM.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20.

PI

Pz

P3

P4

0 25 50 75 100 0 25 50 75 100 0 25 50 75 100 0 25 50 75 100

Lanthanum Sulphate

Praseodymium Sulphate

Nitrogen Carbon mg. fixed consumed nitrogen in mg. fixed/g. in~tg. carbon consumed

Nitrogen Carbon mg. fixed consumed nitrogen in ,ug. in mg. fixed/g. carbon consumed

120.5 133.6 175.9 282.9 345.3 120.5 112.8 153.0 214.5 224.6 163.2 92.2 132.8 199.1 180.3 1:32.8 159.8 188.0 221.5 258.6

5.072 5.218 7.552 7.096 10.268 7.632 4.083 5.649 7.369 9.513 7.007 4.865 7.901 9.72:3 11.550 8.127 9.334 10.498 12.479 14.306

23.7 25.6 23.1 39.8 33.6 16.6 27.6 27.0 29.1 23.6 23.3 18.9 16.8 20.4 17.6 16.3 17.1 11.9 17.5 18.0

120.5 31.5 43.5 58.9 34.1 120.5 175.2 260.2 293.1 265.1 163.2 145.2 204.2 181.1 159.0 132.8 259.1 286.1 239.3 226.5

4.681 4.049 5.758 8.205 9.753 7.632 11.659 18.430 17.817 18.957 7.007 3.032 6.684 9.190 8.704 8.127 13.922 16.442 19.086 20.941

25.7 7.8 7.5 7.1 3.5 16.6 15.0 14.1 14.6 13.8 23.3 4.7 30.5 9.7 18.2 16.3 18.6 19.4 12.5 10.8

sumption values showed enhancement of rates up to 50,uM. concentration of praseodymium ions, again the value increased to 18.957 mg. at 100 pM. Values of mg. nitrogen fixed per g. carbon consumed were inhibitory, as compared to those obtained at 0 pM. concentration. P 3 microorganism, on inoculation in lanthanum sulphate media, gave maximum nitrogen fixation of 199.1,ug. at 75,uM. Minimum fixation was 92.2,ug. in 25 pM. lanthanum-containing media. Carbon consumption rates increased steadily, but at 25 ,uM. the amount decreased greatly to a value of 4.865 mg. Inhibition in mg. nitrogen fixed per g. carbon consumed was a primary feature of the organism in presence of the metal ions. In media containing praseodymium ions P 3 gave erratic nitrogen fixation results. Carbon consumption was lowest at 25,uM. and then an increase was found. Inhibition was erratic in mg. nitrogen fixed per g. carbon consumed with a slight activation at 50,uM. Microbial specimen P4 gave a regular increase in nitrogen fixation values as the concentration of lanthanum sulphate was enhanced. Carbon consumption similarly increased, reaching a maximum at 100,uM. Data of mg. nitrogen fixed per g. carbon consumed showed activation as the metal ion concentration was enhanced. Praseodymium sulphate containing culture media resulted in great activation of nitrogen fixation, and carbon consumption rates were also enhanced, but the results of mg. nitrogen fixed per g. carbon consumed showed inhibition. This was attributed to the fact that the increase in carbon consumption rate was far in excess to the va,riation in the rate of nitrogen fixation.

Activatory Effect of some Rare Earths on Microbial Nitrogen Transformations

,,

. .-_..

~

. .-- ...... --_. , .- .............

489

-.

() ()

Fig. 1. Nitrogen Fixation by Bacteria. Lanthanum ions - - --, praseodymium ions - - - - - - samples: Pl" P 2 X, P 3 8, P4 8.

OL-______

~

______

~

________

~

o Fig. 2. Microbial carbon consumption. Lanthanum ions - - - - , praseodymium ions samples Pl" P 2 X, P a 8, P4 8. 32

ZbJ. Bakt. II. Aht., Bd. 130

______

~

490

K. BAHADUR and P. TJUPATHI, Activatory Effect of some Rare Eart.hs on Microbial ...

,. I

----+.--....... ...

7'---. ,

,

,

\'

'

---~~-------"~

\

~~-.-t,

---} ;>-1-',- -- ,,'/ , ---_ •• -

,"

\

{ •

I

....

-.

I

I

I

-it ..

'

.I

,

"

... -.--:------._-------_ .-..

,',' \ ' , \

--,... ____ •

----

""

Fig. 3. Bacterial nitrogen fixed/carbon consumed. Lanthanum ions - -- - - ,samples:P1 " P 2 x ,P3 8, P 1 !:::l·

, praseodymium ions

In general, lanthanum ions were found to greatly increase the fi xation of nitrogen and the consumption of organic carbon. Due to the high respiratory rate, the corresponding values of mg. nitrogen fixed per g. carbon consumed were lowered. In PI and P 2 overall activation was observed, while inhibi t ion was perceived in P 3 and p .i microbial specimen. Praseodymium ions resulted in inhibition by PI and activation of nitrogen fixation by P2' P 3 , and P 4 • The respiratory rate, i. e., carbon consumption, generally enhanced with few sporadic decreases at 25 !IM. concentration in P3 and P 4 microbial spec im en. Except fOI' erratic increases in mg, nitrogen fixed per g, carbon consumed, the general trend was that of inhibi t ion.

References NICHOLAS, D. J. D. , FISHER, D. J., RADMOND, W. J. , and OSBORNE, M.: Nature 201 (1964) , 79:3. WILLIAMS, R. P.: Endeavour 26 (1967),96 - 100. HIRAYAMA, C.: Univ. Microfilms Dissertation Abstr. 17 (1957),2413. MALSTROM, B. G., and ROSENBURG, A.: Advan. Enzymo!. 21 (1959), 131. KRASIL'NIKOV, N. A. , DROBKOV, A. A., ami SHIROKAR, O. P.: Doklady Akad. Nauk. SSR. 120 (1958) , 1136 - 1137. 6. BURDON, H. L.: Microbiology, Academic Press, London·New York (1964),144 - 154.

1. 2. 3. 4. 5.

Author's address: Prof. Dr. KRISHUA BAHAD UR, Chemical Laboratories, University of Allahabad, Allahabad, U.P., India.

Activatory effect of some rare earths on microbial nitrogen transformations.

Zbl. Bakt. Abt. II, Bd. 130, S. 486-490 (1975) [Chemical Laboratories, University of Allahabad, Allahabad, U.P., India] Activatory Effect of some Ra...
658KB Sizes 0 Downloads 0 Views