JA C EK M A LICK I
ECOLOGICAL BASE FOR THE INTERPRETATION OF THE BACTERIAL COUNT IN THE SOIL
In stitu te of M ath em atics, P h y sic s and C h em istry, T ech n ica l U n iv e r sity of L u b lin
IN T R O D U CTIO N
Investigations on the soil bacteria, especially on the saprophytic bacteria, are based mostly on the m ethods adopted from both the bacteriology and technical microbiology. However the soil is a specyfic structure, which cannot be artificially reproduced by means of either selective or the totally m ultiplying media. This prom pted extensive studies on new methodological solutions accessible in the soil m icro biology. The results obtained in the course of such studies used to neglect the stru ctu re and differences between both m ineral and organic soils.
In this paper attem pts are presented of a new approach to th e interpretation of the quantitative data from the investigations of the soil bacteria. This new way of the interpretation involves the fertility of the soils. The real life environm ent for the soil m icroorganisms is form ed by the solutions of n u trients in a gravitational and capillary w ater. Therefore it seems to be reasonable th a t any quaititative results
dealing w ith the bacterial count refered to 1 cm3 of the soil solution
present in soil while collecting sample ra th e r than to 1 g of air-dried
soil, 1 g of organic m atter, 1 cubic cm soil etc. The resu lt can be v eri fied by the results originated from the non-microbiological investiga tions.
M A TE R IA L S A N D M ETHODS
The samples w ere investigated of the soils from four fields in the area of Bachus forest reservation w ithin Forest Inspectorate Chełm (Forest D istrict Sawin). The selection of fields is based on the phyto sociologic analysis. The plant complexes on the chosen fields, were
characterized as : Tilio Carpinetum typicum , Carici elongatae-Alnetum ,
Pino-Quercetum and Querco-Piceetum. The order of the soils according
to their trophic range was constructed on the basis of the prior ecological, phytosociological and pedological studies [2]. Following both to the regulations given in the “C ultivation rules compulsory in the State Forest F arm ing” [7] and “Forest soil classification” [4].
The soil was taken from under the patches of dom inating kinds of the undergrow th. The 100 cubic cm stain steel tubes (5 cm high) according to S. Zawadzki (Institute of M elioration and G reen Grounds in Lublin) were applied for collecting samples.
The soil (20 of 1 0 0 cubic cm) samples sim ultaneously from each field
w ere taken every m onth from the horizon A. The samples of the soil of the total volume of 8000 cubic cm were collected from the field of
the area of 1600 m 2. The samples were m easured after 6 hrs period
necessary for their delivery from the field to the laboratory. The total num ber of the bacteria was established using the direct method w ith fluoroscein isothiocyanate (FITC) and the HBO 200 lamp equipped w ith
both the VG1 (2 mm) filtred and the OGI, GG9 barrage filter [1, 5, 6].
The w eight by volume and volume of the soil solution was determ ined according to K a u r i c e v [3]. The results of the m easurem ents (Table
2) were calculated on 1 g of the mass of dry soil assuming th a t :
num ber of bacteria in 1 cubic cm of the soil
X = ________________________________________________________
volume w eight of the soil and on 1 cm3 of the soil solution w here
num ber of bacteria in cubic cm of the soil
X =
---actual volume of the soil solution
S.vjv: p h y s i c a l p r o p e r t i e s o f t h e e x a m i n e d s o i l s S o i 1 5 Ce-A Q-l? jj i’-Q B ulk d e n s i t y 0 ,3 0 6 0 .2 7 8 0 .7 9 6 i1 0 . / 2 0 P o r o s i t y in % 63 48 35 33 V 5 3 .2 4 0 ,6 2 5 ,6 2 S . A VI 5 2 ,4 39. i 26 » 0 :■ 7 ,3 M o istu re in % V II 4 3 .6 3 7 .8 23 . 1 2 2.1 o f volume s o i l s V III 30« 1 3 3 .2 1 9,8 ',6 .6 j_X 5-1,3 2 9 .1 2 4 .2 2 5 .3 X 5 5 .5 3 0 .9 2 3 .5 2 2 .6
Ci. - r u.v:Lc i 3 on/’. ita e - /lino turn Q-.P - Q u c rc c -P ic n e turn ï-C - i l i o - C u r r i n e t u® t y p i c an P—Q - Pino--Q uarto turn
T a b l e 2 T o t a l number o f b a c t e r i a l c o l l s x 10 i n th o ex-irainod a c i l n r e f e r r e d t o i 1 g a i r - d r i e d s o i l , 1 c u b ic си s o i l and 1 cn»'5 s o i l s o l u t i o n 1 g a i r - d r i o d s o i l 1 c u b ic cm p o ll 1 cni^ s o i '1 с о l u t io n Сс-Л Q-P T-C P-Q Ce-A Q-P T-C P-Q Ce-A Q-P ?-C P-Q V 7800 4402 2724 1151 2387 1224 2169 1140 4101 3014 8472 4318 VI 7107 4237 2688 1283 2175 1173 2140 1271 4150 3012 8230 4571 V II 6013 3766 2353 1026 1840 1047 1377 1016 4220 2769 8125 4597 V III 3934 3395 2040 867 1204 944 1624 859 4000 284 3 8202 4618 IX 7506 2751 2513 1163 2297 765 2001 1152 4191 2623 0263 4553 X 7473 3460 2457 962 2287 962 1956 953 4120 3113 0 323 4216
The significance of the statistical difference in the population of the soil under investigation by the bacteria was found by means of both the analysis of variance and the calculation of the Tukey confidence half intervals.
R E SU L T S A N D D ISC U SSIO N
Since the results of all the phytosociologic, ecologic and pedologie
studies are already well defined [2] we could arrange the soil examined
in following order of decreasing fertility : the soil from the horneam - lime forest, w ith the Tilio-Carpinetum association > the soil of the mixed pine forest, of the Pino-Quercetum association > the soil from the older swamp forest, of the Carici elongatae-Alnetum association > the soil of the mossy swamp pine forest of the Querco-Piceetum associa tion. Some physical properties of the exam ined soils are given in Table
1. D ata in Table 2 characterize the soils exam ined by means of the
num ber of the bacterial cells present in 1 cubic cm and 1 g of the soil
as well as in 1 cm8 of the solutions. The num ber of the bacterial cells
present in 1 cubic cm of the soils does not allow to distinguish p articular soils. Though the value of the test function F =70.24 has been obtained at the value needed for 3 and 44 degreses of freedom (F001;3;44=4.26) still the least significant difference L m = 191X10® allows hardly to distribute these soils into the pairs. The soils of the older swamp forest as well as of the hornbeam -lim e forest are not different from one another. However, both are different from the pair of soils of the mixed pine and mossy swamp forests. On the other hand the interpretation of the data in Table 2 concerned w ith the num ber of the bacterial cells
in 1 g of the soil bads to the essentially different conclusions. This is
additionally illustrated (Fig. 1) which shows the num ber of bacteria in four kinds of the soil depending on period of the year studied from May through October. In both the m anners of the in terpretation the
T otal n u m b er of b a cteria l ce lls in ex a m in e d so ils referred to : 1 g a ir-d ried soil. 1 cubic cm soil and 1 cm 3 soil solu tion
l — Ca rici e lo n g a te a e A ln e tu rn , 2 — Q u e r c o P i c e e t u m , 3 — T i l i o C u r p m e n t u m t y p i c u m , 4 — P in o -- Q u c r c e t u m
shape and the positions of the lines exibit the distinct spring and autum m axim a as well as the sum m er depression of the num ber of bacteria and it can be obviously m et in m any sources. The variance analysis shows th a t if the results are related to 1 g of the soil investigated can also be classified based on the num ber of bacteria (F = 144.4 at the
dem anded test function F 001;3;44 = 4.26 and L000i = 984X10°). The order
of the soils arranged based on num ber of the bacteria in 1 g of the soil does not follow the order derived from the calculations related to 1 cubic cm of the soil and both the orders do not agree w ith the non- microbiological evaluation of the quality of the soil given by the trophic order. However if has appeared th a t the microbiological evaluation of the quality of the soil can correspond to non-microbiological approach to th a t problem. It can be achieved if the num ber of the bacteria is related to 1 cm3 of the soil solution. The num ber of bacteria distinguis hes betw een the soils exam ined on a statistically essential way. The value of the test function F=1675 a t the dem anded level F 00i;3;44= 4.26 and
of Looo2 = 279X 10®. The relation betw een both recent microbiological
orders and th a t new ly proposed is illustred in Fig. 1. This observation disagrees w ith a commonly opinion in this respect. Since this opinion comes from the considerations related to either 1 g or 1 cubic cm of the soil it can be easily rationalized. The decrease in the am ount of biomass depending on the season is due to the evaporation of the m oisture of the soil. Because in our approach the constant volume of the soil solution has became the reference to the form erly observed decrease of the am ount of the biomass during the sum m er period is cannot take place. Thus the num ber of the bacteria is dependent solely
on the fertility of the soil. In this trea tm en t the uniform total num ber
of the bacteria in 1 cm3 of the soil solution is actually independent of
the season being considered. This suggests that, continously given physiological groups of bacteria can exist in the active form. On such a w ay the biomass of bacteria is lim ited solely by the accesibility of all the energetic and m ineral sources.
If should be noted th a t the num ber of bacteria estim ated by means of the methods of cultivation does not allow to obtain the saisfactory results after introducing suggested w ay of interpretation, because of the lack of the nourishm ents, which could reproduce n atu ra l conditions of the soil.
R EFEREN CES
[1] В a b i u к L. A., P a u l E. A. : T he u se of flu o r e sc e in iso th io cy a n a te in th e d eterm in a tio n of th e b a cteria l b iom ass of grasslan d soil. Can. J. M icrob. 16, 1970, 57-62.
[2J F i j a ł k o w s k i D. : F orest reserv e “B a ch u s” n ear C hełm . A nn. U n iv . M. C u rie-S k ło d o w sk a , S ec. C, 14, 1959, 297-342.
[3] K a u r i c e v J. S. : P ra k tik u m po p o ch v o v ied en iu . M oscow 1973, 1-279. [4] K r ó l i k o w s k i L. : C la ssific a tio n of fo rest soils. W arsaw 1969, P ol. T ow .
G leb. K om . G en ezy K las. i K art. (m in eograp h ed typ escrip t).
[5] M a l i c k i J. : A q u ick m ethod of d irect d eterm in a tio n of th e n u m b er of b acteria in soil. A nn. U n iv . M. C u rie-S k ło d o w sk a , Sec. C, 27, 1972, 289-293. [6] M a 1 ic к i J. : C om parison of m icrobiological a ctiv ity of soils of d efin ite forest
com m u n ities. U M CS L u b lin , 1976, 1-84.
[7] M in istry of F o restry and F o rest In d u stry, G en era l B oard of S ta te F o rests : B reed in g p rin cip les v a lid in sta te fo restry . P W R iL W arsaw , 1969, 1-410.
J. M ALICKI
EKOLO GICZNE P O D ST A W Y IN T ER PR E T A C JI LIC ZEBNO ŚCI G LEBO W Y CH B A K TE R II
I n sty tu t M atem atyk i, F iz y k i i C h em ii P o lite c h n ik i L u b elsk iej
S t r e s z c z e n i e
L iczeb n ość k om órek b a k terii g le b o w y c h w g leb a ch le śn y c h rezerw a tu B ach u s o k reślan o b ezp ośred n ią m etod ą z w y k o r z y sta n ie m izo tio cja n a tu flu o r e sc e in y (FITC) i la m p y H BO 200 z filtr e m V G1 (2 mm) oraz zaporow ym filtre m OGI; GG9.
B ad an iu p oddano cztery g le b y z p o w ierzch n i, k tó ry ch zb io ro w isk a ro ślin n e s k la sy fik o w a n o jako: C a rici e lo n g a ta e -A ln e tu m (C e-A ), Q u e rc o -P ic e e tu m (Q -P ), Ti-?
lio -C a r p in e tu m ty p ic u m (T-C ), i P in o -Q u e rc e tu m (Р-Q). O ceny tro fizm u bad an ych
g leb dokonano w oparciu o w y n ik i badań fito so cjo lo g ic zn y ch i k ieru ją c się za ło żen ia m i z a w a rty m i w p rezp isach „Z asady h o d o w la n e o b o w ią zu ją ce w p a ń stw o w y m
go sp o d a rstw ie le ś n y m ”. P rób k i gleb p obierano p ierścien ia m i z n ierd zew n ej stali, op racow an ym i w In sty tu cie M elioracji i U ż y tk ó w Z ielon ych w L u b lin ie przez Z aw ad zk iego. O bjętość roztw oru g leb o w eg o obliczano z różn icy m ięd zy m asą 100 cm3 gleby w stanie natu raln ym i po w ysu szen iu do stałej w agi w 105°C. P o row atość i ciężar o b jęto ścio w y ok reślan o w ed łu g K au riczew a.
W yn ik i badań p rzed staw ion o w tab. 1 i 2 oraz na rys. 1. Po p rzep row ad zen iu a n a lizy w y n ik ó w prop on u je się rela c jo n o w a n ie rezu lta tó w o k reśla n ia liczeb n o ści b ak terii g leb o w y ch w stosu n k u do 1 m l roztw oru glebow ego, a n ie do 1 g lub 1 cm 8 gleb y.
Dr Ja c e k M a lick i
I n s t y t u t M a t e m a t y k i , F i z y k i i C h e m i i P o l i t e c h n i k i L u b cis ki e j
