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Interrelation between Cellulase Activity and Humus Content in the Steppe Soils of South-East Zabailalye
Zbl. Bakt. Abt. II, Bd. 128, S. 140-143 (197:3) [State Pedagogieal Institute, Botany Department, Irkutsk]
Interrelation between Cellulase Activity and Humus Content in the Steppe Soils of South-East Zabailalye V. P.IGslitsina Summary Organic carhon plays an impol·tant role in pedogenesis. OUI' paper deals \\,ith cellulose as the main eBl'hon sow'ce in soil. The cellulolytic activity of South-East Zahaikalye soils (Ouon-.\I·gun steppe) \\'as studied, The relations hetween activity of cpHulases, thp cPilulose content Qf plants, and the eellulolytic llli('rooq~anism couuts was determined. The cellulolytic activity of these soils llIay indicatc the intensity and the dil'eetion of soil ol'ganic rna tter transforma tions. The study of intimate pl'Ocesses, going on in the soil, and lleterminillg its fertilit~· is of great theoretical and practical importance. In this connection, investigalion of the soil biological activity gives an idea of the direetions and the intensity of reaetioJls releasing the nutrients and controlling their natural re-cye1ing. Carbon transformation, and partieularly cellulose mineralization, plays an important role in this process. In nature, this process is going on due to the mierobial activities and due 10 cellulases, produeed by microorganisms. The present paper deals with the latter problem. Materials and Methods \\'c stu,lied the intensity of ecHulosc decomposition of ['l:mt residues in the steppe faeies soils of South-East Zahaikalye. The cellulase aetivity was estimated h~· til" antl'one Illethod, lleveloped previously (KISLITSINA 19(io).
Results and Discussion Some estimated data of cellulolytic activity of the soils in this region arc given in Table L The table shows that the black earths of the Onon-Argun steppe differ (~onsider ably in the cellulase aetivity. A ehange in th(~ activity with the depth can be explained by the humus content in these soils. It should he noted that the black earths of Zabaikalye differ from their European ana~ogs in a low humus content (~OGIN 1966). The organic substance mineralization process in the soils of the reg-ion in qnestion is going on slowly, which is connected with the peeulial' hydro-thermal conditions. On the other hand, the present state can be explained by a relati\'ely lal'ge amount of the underground biomass (SNI'l'KOW70). This fact is well illustrated by the data of humus content and cellulase activity in the meadow blaek soil Crable J), where the activity goes down in the (O['oss section, foHowing the change in the humus content. In the saline black soil, the ecJlulolytic activity of the lower horizons decreased similarly as the content of organic sllhstances. The study of cellulose-deeomposing microflora showed tha t thl~ dominan t forms in the upper horizons are bacteria and fungi, whereas the dominant forms in the deep soil layers al'e actinomyeples (KISLITSINA and KOZLOV 1968).
141
Tnt'·''J'ehrl.ioll ],et\\'eel\ C,'lIl\lase .\c\.ivity Tahle 1 Cellulase aetivity in the llIain t~'IH'S of soils of South-Eas\. Zub"ikalye Snil
Cellulase lletiyjty (y of glucose Jll'" 1 g. soil)
Ih'pth (Cill.)
lJUIlluS ("i,,)
2
:1
Ii
3.77
350 :ll)O 2J:) :WO HiO /20
-
.\Ipadow "lack soil
(1-
30
:10- TJ.
:LI!)
2.G!) :1.31 1.2.1 O.7J
72- 120 120-:1.50 150-IJr, j7;j-220 (al'''ol,n\.e black I",il
!)
1,.2.,
2:-:: 1,0 li:1
2.07 0.!J7 0.71) IUiO
0- 22
:l.!):l U) .1 J .1,:1 J.O() 0.:;:,
0!)281,00:1-
Sali"e hlack soil
1';,
22- Ii:l
1,3-
Ii()
1;6- !)"
!):)-12:1 J2.'l-:l::iO
:120 270 21iO l70 100 J:lO K")
x·
c~)
8.'3 70
o,:n
fi2
Table 2 Tnfluelwe of highe]' "egetation
011 (~ellilinse
nctivity of hlack snils in South-Enst Zabaikalye
C"ilSS pl'odll(,ti\'it~~indcx
or indh-idllill
fnei('S in °,0
FH('lPS
-.
\\heetgl'ass - stipa Tansy - stip:' Tansy Stipa - t.nnsy
Tot,,] ae"ial h;omnss --
73 ;,0
:):; :~2
Tansy
Stipn
\\ hee1.g'l'ass
0 :12 90 .100
100 80
7J 22 15 :1
--
10 7
CeBuJase netivity (y of glueose pel' J g, soil)
,woo
,WOO
2300 '1250
Edi ficato/'s among f Illlgi aJ'e J'epresental i"cs of genern Penicilli It1/) , Dematium., Trichoderma, ChaelorniulII, Fusarium., Alternaria, haetcria - Sporocyl-ophago, and Actinomyces - varieties of thc series LII-vendulo-Roseus. As was established recently (KISLITSINA '1966), the properties of this physiological ~I"()IIP of microorganisms and their aetivities depend on the soil temperature, moistnrl', and the presence of .n-ailable forms of nitrogen. The higher the content of
142
V. P. Kislitsina
indicator of the soil mobilization capacity. In this respect, the fungi of genus Dematium are the least desired. They dominated in soils with a slightly manifested mobilization process. The fungi of genera Fusarium and Chaetornium are more useful for the nitrogen nutrition of plants. The bacterial flora is more desired in this respect than fungi. The black soils under investigation are very poor in nitrates (0.5-7.0 mg.jkg.) and contain easily dissoluble compounds of ammonia nitrogen (4-13 mg.jkg.) (KHOKHLOVA 1970). That is why the prevailing cellulose-decomposing organisms do not require the rich sources of nitrogen. In soils that are poor in humus, as well as in salt soils (saline soils and salt marshes), the cellulase activity is 2-3 times lower than in black soils. Salinity suppresses the development of cellulose-decomposing microorganisms in soil, especially bacteria, therefore the cellulose decomposition has been going Oil very slowly there. Green plants essentially influence the cellulase activity in steppe soils (Table 2). This table shows that the most productive facies possess the topmost cellulolytic activity of soils. The cellulose content in adificator plants is also connected with the cellulase activity. Thus, Tansy Siberian (Tanacetum sibiricum) contains 24.51 pel' cent of cellulose, Stipa (Stipa baicalensis) - 32.01 pel' cent,Wheet-Grass - 35.30 per cent. Stipa is dominant in the wheetgrass - stipa facies. According to the data obtained by DRUZHININA (1970), the productivity index of this plant amounts to 100 per cent. In the tansy - stipa facies the index under study goes down to 80 pel' cent, similarly as the cellulase activity. Tansy, whose cellulose content is lower than that of Stipa, is dominant in the tansy and the stipa - tansy facies. These facies also reveal a lower cellulase activity. The cellulolytic activity also coincides with the presence of humus in these facies. Thus, the humus content in the stipa facies is higher than in the tansy facies (4.22 pel' cent, 3.66 pel' cent, respectively). Cultivated plants take part in the accumulation of organic substances in soil. We can estimate the intensity of the mineralization process by the cellulase activity in soil. There are favourable conditions for the activity of cellulose-decomposing microorganisms and enzymes, produced by them in the arid zone of South-East Zabaikalye in certain periods. These enzymes take part in the processes of formation and mineralization of humus in soil in these periods. Since the steppe black soils have a large volume of edaphotope, compared to the taiga soils of Eastern and Western Siberia, the mineralization capacity of arid soils is higher than in other landscapes of the Siberian zones (KOZLOV 1970). That is why the cellulase activity can be used for estimating the intensity of organic substance mineralization processes in the soil. On the other hand, this relation between the cellulolytic activity and the humus content in the soil permits to employ the test also for indexing the soil in organic substances (humus) supply. Zusammenfassung Organischer Kohlenstoff spielt eine wichtige Rolle in del' Bodenbildung. Unsere Mitteilung befaBt sich mit del' Zellulose als einer Hauptquelle des Kohlenstoffs im Boden. Die zellulolytische Aktivitat del' Boden im siidostlichen Zabaikalien (Steppengebiet zwischen Onon und Argun) wurde untersucht. Es wurden die Beziehungen zwischen del'
Interrelation between Cellulase .\ctivity
143
Aktivitiit del' Zellulasen, clem Zclllllosegehalt del' Pflanzen und del' Zald del' zellulolytischen Mikroorganismen determiniert. ,·\.lIS del' zellulolytisehen Aktivitat diesPI' Boden kann man Folgel'llllgeuAuf den Umsatz del' o,,!!anischen Substanz im Boden ziehen.
Literature DRUZHININA, ~. P.: Biomass of the serial part of the grass COVOl'. Colleclion "Topology of Steppe Geosystems", p, 91- 105 (1970). - KHOKHLOVA, T. I.: Soils and the soil-forming ['rocesses. "Topology of Steppe Geosystems", •. NAuka", p. 70-79 (1970). - KISLITSINA, V. P.: CelJlllnse activity of some soils of Eastern Siberia and microorganism cultures extracted from them. Irkutsk State Cniversity; Thesis for Master of Biology, Irkutsk 1966. - KISLITSINA, V. P., nnd KOZLOV, IC A.: Influence of different SOU1Tes nf nitrogen on accumulation of a!'live cellulnscs by mieroOl'gnnism cultures extracted from the soils of Eastern Siberia. Applied Biochemistry and :\licrobiology, Vol. IV (1968), p. 97- :102, - KOZLOV, K. A.: Biological activity of soils in Eastern Siberia; Thesis for Master of Biology. Leningrad 1970. - N OGINA, X..\.: Soils of Zabaikalye, "~auka" (1964). - SNITKO, V, A.: (;eochemistl'~' of depression. "Topology of Steppe Geosystems". "Nauka", p. 127-131, (1970).
AuthOl"s address: Ih. V..Kislitsina, Botan~' Depal'tlnent, State PedAgogical Institute, Irkutsk (L.S.S.n.).
Interrelation between Cellulase Activity and Humus Content in the Steppe Soils of South-East Zabailalye V. P.IGslitsina Summary Organic carhon plays an impol·tant role in pedogenesis. OUI' paper deals \\,ith cellulose as the main eBl'hon sow'ce in soil. The cellulolytic activity of South-East Zahaikalye soils (Ouon-.\I·gun steppe) \\'as studied, The relations hetween activity of cpHulases, thp cPilulose content Qf plants, and the eellulolytic llli('rooq~anism couuts was determined. The cellulolytic activity of these soils llIay indicatc the intensity and the dil'eetion of soil ol'ganic rna tter transforma tions. The study of intimate pl'Ocesses, going on in the soil, and lleterminillg its fertilit~· is of great theoretical and practical importance. In this connection, investigalion of the soil biological activity gives an idea of the direetions and the intensity of reaetioJls releasing the nutrients and controlling their natural re-cye1ing. Carbon transformation, and partieularly cellulose mineralization, plays an important role in this process. In nature, this process is going on due to the mierobial activities and due 10 cellulases, produeed by microorganisms. The present paper deals with the latter problem. Materials and Methods \\'c stu,lied the intensity of ecHulosc decomposition of ['l:mt residues in the steppe faeies soils of South-East Zahaikalye. The cellulase aetivity was estimated h~· til" antl'one Illethod, lleveloped previously (KISLITSINA 19(io).
Results and Discussion Some estimated data of cellulolytic activity of the soils in this region arc given in Table L The table shows that the black earths of the Onon-Argun steppe differ (~onsider ably in the cellulase aetivity. A ehange in th(~ activity with the depth can be explained by the humus content in these soils. It should he noted that the black earths of Zabaikalye differ from their European ana~ogs in a low humus content (~OGIN 1966). The organic substance mineralization process in the soils of the reg-ion in qnestion is going on slowly, which is connected with the peeulial' hydro-thermal conditions. On the other hand, the present state can be explained by a relati\'ely lal'ge amount of the underground biomass (SNI'l'KOW70). This fact is well illustrated by the data of humus content and cellulase activity in the meadow blaek soil Crable J), where the activity goes down in the (O['oss section, foHowing the change in the humus content. In the saline black soil, the ecJlulolytic activity of the lower horizons decreased similarly as the content of organic sllhstances. The study of cellulose-deeomposing microflora showed tha t thl~ dominan t forms in the upper horizons are bacteria and fungi, whereas the dominant forms in the deep soil layers al'e actinomyeples (KISLITSINA and KOZLOV 1968).
141
Tnt'·''J'ehrl.ioll ],et\\'eel\ C,'lIl\lase .\c\.ivity Tahle 1 Cellulase aetivity in the llIain t~'IH'S of soils of South-Eas\. Zub"ikalye Snil
Cellulase lletiyjty (y of glucose Jll'" 1 g. soil)
Ih'pth (Cill.)
lJUIlluS ("i,,)
2
:1
Ii
3.77
350 :ll)O 2J:) :WO HiO /20
-
.\Ipadow "lack soil
(1-
30
:10- TJ.
:LI!)
2.G!) :1.31 1.2.1 O.7J
72- 120 120-:1.50 150-IJr, j7;j-220 (al'''ol,n\.e black I",il
!)
1,.2.,
2:-:: 1,0 li:1
2.07 0.!J7 0.71) IUiO
0- 22
:l.!):l U) .1 J .1,:1 J.O() 0.:;:,
0!)281,00:1-
Sali"e hlack soil
1';,
22- Ii:l
1,3-
Ii()
1;6- !)"
!):)-12:1 J2.'l-:l::iO
:120 270 21iO l70 100 J:lO K")
x·
c~)
8.'3 70
o,:n
fi2
Table 2 Tnfluelwe of highe]' "egetation
011 (~ellilinse
nctivity of hlack snils in South-Enst Zabaikalye
C"ilSS pl'odll(,ti\'it~~indcx
or indh-idllill
fnei('S in °,0
FH('lPS
-.
\\heetgl'ass - stipa Tansy - stip:' Tansy Stipa - t.nnsy
Tot,,] ae"ial h;omnss --
73 ;,0
:):; :~2
Tansy
Stipn
\\ hee1.g'l'ass
0 :12 90 .100
100 80
7J 22 15 :1
--
10 7
CeBuJase netivity (y of glueose pel' J g, soil)
,woo
,WOO
2300 '1250
Edi ficato/'s among f Illlgi aJ'e J'epresental i"cs of genern Penicilli It1/) , Dematium., Trichoderma, ChaelorniulII, Fusarium., Alternaria, haetcria - Sporocyl-ophago, and Actinomyces - varieties of thc series LII-vendulo-Roseus. As was established recently (KISLITSINA '1966), the properties of this physiological ~I"()IIP of microorganisms and their aetivities depend on the soil temperature, moistnrl', and the presence of .n-ailable forms of nitrogen. The higher the content of
142
V. P. Kislitsina
indicator of the soil mobilization capacity. In this respect, the fungi of genus Dematium are the least desired. They dominated in soils with a slightly manifested mobilization process. The fungi of genera Fusarium and Chaetornium are more useful for the nitrogen nutrition of plants. The bacterial flora is more desired in this respect than fungi. The black soils under investigation are very poor in nitrates (0.5-7.0 mg.jkg.) and contain easily dissoluble compounds of ammonia nitrogen (4-13 mg.jkg.) (KHOKHLOVA 1970). That is why the prevailing cellulose-decomposing organisms do not require the rich sources of nitrogen. In soils that are poor in humus, as well as in salt soils (saline soils and salt marshes), the cellulase activity is 2-3 times lower than in black soils. Salinity suppresses the development of cellulose-decomposing microorganisms in soil, especially bacteria, therefore the cellulose decomposition has been going Oil very slowly there. Green plants essentially influence the cellulase activity in steppe soils (Table 2). This table shows that the most productive facies possess the topmost cellulolytic activity of soils. The cellulose content in adificator plants is also connected with the cellulase activity. Thus, Tansy Siberian (Tanacetum sibiricum) contains 24.51 pel' cent of cellulose, Stipa (Stipa baicalensis) - 32.01 pel' cent,Wheet-Grass - 35.30 per cent. Stipa is dominant in the wheetgrass - stipa facies. According to the data obtained by DRUZHININA (1970), the productivity index of this plant amounts to 100 per cent. In the tansy - stipa facies the index under study goes down to 80 pel' cent, similarly as the cellulase activity. Tansy, whose cellulose content is lower than that of Stipa, is dominant in the tansy and the stipa - tansy facies. These facies also reveal a lower cellulase activity. The cellulolytic activity also coincides with the presence of humus in these facies. Thus, the humus content in the stipa facies is higher than in the tansy facies (4.22 pel' cent, 3.66 pel' cent, respectively). Cultivated plants take part in the accumulation of organic substances in soil. We can estimate the intensity of the mineralization process by the cellulase activity in soil. There are favourable conditions for the activity of cellulose-decomposing microorganisms and enzymes, produced by them in the arid zone of South-East Zabaikalye in certain periods. These enzymes take part in the processes of formation and mineralization of humus in soil in these periods. Since the steppe black soils have a large volume of edaphotope, compared to the taiga soils of Eastern and Western Siberia, the mineralization capacity of arid soils is higher than in other landscapes of the Siberian zones (KOZLOV 1970). That is why the cellulase activity can be used for estimating the intensity of organic substance mineralization processes in the soil. On the other hand, this relation between the cellulolytic activity and the humus content in the soil permits to employ the test also for indexing the soil in organic substances (humus) supply. Zusammenfassung Organischer Kohlenstoff spielt eine wichtige Rolle in del' Bodenbildung. Unsere Mitteilung befaBt sich mit del' Zellulose als einer Hauptquelle des Kohlenstoffs im Boden. Die zellulolytische Aktivitat del' Boden im siidostlichen Zabaikalien (Steppengebiet zwischen Onon und Argun) wurde untersucht. Es wurden die Beziehungen zwischen del'
Interrelation between Cellulase .\ctivity
143
Aktivitiit del' Zellulasen, clem Zclllllosegehalt del' Pflanzen und del' Zald del' zellulolytischen Mikroorganismen determiniert. ,·\.lIS del' zellulolytisehen Aktivitat diesPI' Boden kann man Folgel'llllgeuAuf den Umsatz del' o,,!!anischen Substanz im Boden ziehen.
Literature DRUZHININA, ~. P.: Biomass of the serial part of the grass COVOl'. Colleclion "Topology of Steppe Geosystems", p, 91- 105 (1970). - KHOKHLOVA, T. I.: Soils and the soil-forming ['rocesses. "Topology of Steppe Geosystems", •. NAuka", p. 70-79 (1970). - KISLITSINA, V. P.: CelJlllnse activity of some soils of Eastern Siberia and microorganism cultures extracted from them. Irkutsk State Cniversity; Thesis for Master of Biology, Irkutsk 1966. - KISLITSINA, V. P., nnd KOZLOV, IC A.: Influence of different SOU1Tes nf nitrogen on accumulation of a!'live cellulnscs by mieroOl'gnnism cultures extracted from the soils of Eastern Siberia. Applied Biochemistry and :\licrobiology, Vol. IV (1968), p. 97- :102, - KOZLOV, K. A.: Biological activity of soils in Eastern Siberia; Thesis for Master of Biology. Leningrad 1970. - N OGINA, X..\.: Soils of Zabaikalye, "~auka" (1964). - SNITKO, V, A.: (;eochemistl'~' of depression. "Topology of Steppe Geosystems". "Nauka", p. 127-131, (1970).
AuthOl"s address: Ih. V..Kislitsina, Botan~' Depal'tlnent, State PedAgogical Institute, Irkutsk (L.S.S.n.).