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[Luminescent-microscopic study of soil microorganisms].

Soil microorganisms can be quantitatively assayed by means of a technique which makes use of staining preparations on slides with acridine orange. When bacterial cells were counted daily in humus-gleisolic soil, their number did not depend on time if the soil was incubated for five days. Mixed soil samples corresponding to the same time of incubation differed reliably in the bacterial number. The paper presents a scheme for determining the necessary number of samples, preparations, and fields of vision when the number of bacteria is being estimated. It is expedient to take 7 samples from a soil mixture, to make 2 preparations out of each sample, and to count bacteria in 5 fields of vision for each preparation.

Acridines↗
PubMed1978

Interrelationships between soil microorganisms and polystyrene.

Transmission and scanning electron microscopy along with autoradiographic procedures were used for evaluating the interrelationship between soil microorganisms and polystyrene. Two hypotheses, allowing to explain the properties of polystyrene as a soil conditioner, were investigated: the first is concerned with a possible action of soil microorganisms on the compound; the second, reciprocally, with the polystyrene interference on microorganisms. Radioactivity translocation of 14C-Ecolyte-polystyrene along fungal hyphae and asexual fructification of strains, isolated from soil, as well as cytological modification at the cell wall level of the same microfungi, cultivated in the presence of polystyrene have been ascertained.

Cladosporium↗
PubMed1978

A screening technique for assessing effects of pesticides on population and activities of non-target soil microorganisms.

A simplified technique for assessing the effect of pesticides on non-target soil microorganisms was developed. Changes in microbial population determined by the dilution plate method, in nitrification by the soil perfusion technique, and in oxygen consumption using a differential respirometer are the only measurements required. A comparison of the effects observed for three pesticides, dieldrin, chlorpyrifos and Vorlex, in three soil types with those produced by an antibiotic, a fungicide, a nitrification inhibitor and steam pasteurization of the soil clearly demonstrate the effectiveness of the simple technique.

Chlorpyrifos↗
PubMed1976

Degradation of [8,9,-14C]endosulfan by soil microorganisms.

Twenty-eight soil fungi, 49 soil bacteria, and 10 actinomycetes were tested as to their ability to degrade the insecticide endosulfan. Using 14C-labeled material, the qualitative as well as the quantitative formation of metabolities, as well as of 14CO2, could be followed. Sixteen fungi, 15 bacteria, and 3 actinomycetes were found capable of metabolizing more than 30% of the applied endosulfan. The major metabolities detected were endosulfate, formed by oxidation of the sulfite group, and endodiol, formed by hydrolysis of the ester bond. The majority of highly active fungi formed endosulfate as the major metabolite, whereas the majority of active bacteria formed endodiol. In addition to endosulfate and endodiol, individual cultures contained small quantities of endohydroxyether and two unidentified products. The very small quantities of 14CO2 evolved from cultures indicated that an extensive mineralization of the carbon skeleton of endosulfan did not occur.

Actinomycetales↗
PubMed1976

Products of soil microorganisms in relation to plant growth.

A survey has been made of the range and activity of the organic products of soil microorganisms which have a direct influence on plant growth. Microbial metabolites which effect plants indirectly by the modification of the soil environment are also reviewed. The sources of substrates for the production of metabolites in soil and the farming practices which give rise to them are considered. It is stressed that an interdisciplinary approach is needed in the manipulation of microbiological activity in soil.

Agriculture↗
PubMed1975

A simple fluorescence of staining technique for in situ soil microorganisms.

A simple, rapid straining technique using the magnesium salt of 1-anilino-8-naphthalene sulfonic acid is described. Treatment of soil with an aqueous, membrane-filtered solution (3.5 mg/ml) of the salt causes the soil microorganisms to fluoresce when examined with light from a mercury arc light source.

Anilino Naphthalenesulfonates↗
PubMed1976

Utilization and degradation of lindane by soil microorganisms.

Of 147 microorganisms isolated from a loamy sand, 71 showed good growth with lindane (gamma-1,2,3,4,5,6-hexachlorocyclohexane) and produced chloride in an aqueous medium. Thirteen soil microorganisms were selected to study the utilization of lindane. Lindane was metabolized by the microbes to gamma-2,3,4,5,6-pentachloro-1-cyclohexene (gamma-PCCH), alpha-3,4,5,6-tetrachloro-1-cyclohexene (alpha-TCCH), beta3,4,5,6-tetrachloro-1-cyclohexene (beta-TCCH), gamma-3,4,5,6-tetrachloro-1-cyclohexene (gamma-TCCH), and pentachlorobenzene (PCB). Cells of Pseudomonas sp. No. 62 grown on lindane simultaneously adapted to gamma-PCCH, alpha-TCCH, beta-TCCH, gamma-TCCH, PCB, 1,2,3,4,-tetrachlorobenzene (1,2,3,4-TCB) and 1,2,4,5-tetrachlorobenzene (1,2,4,5-TCB). The bacteria degraded each of these chemicals at least partially as indicated by an increased rate of oxygen consumption.

Actinomycetales↗
PubMed1978

Interaction of atrazine with soil microorganisms: population changes and accumulation.

A loam soil treated with atrazine at rates of 10, 30, and 100 microgram/g soil resulted in increased populations of actinomycetes, bacteria, and fungi over those in non-treated soil. The increases were in proportion to the amount of atrazine and persisted for at least 2 months. Living actinomycete amd fungal mycelia were incubated for 48 h in distilled water, nutrient broth, or soil containing 5 microgram/ml (g) of the herbicide. Actinomycete and fungal mycelia accumulated atrazine from water to concentrations up to 87-fold and 132-fold, respectively, over that in the ambient medium. The maximum accumulation from soil by actinomycete mycelia was 26-fold and by fungal mycelia 13-fold. Fungi accumulated little or no atrazine from a nutrient medium whereas actinomycetes accumulated up to 13-fold. Dead mycelia usually did not accumulate atrazine in excess of the ambient concentration. Mycelium of Sclerotium rolfsii growing in a nutrient medium containing 20 microgram atrazine/ml accumulated 157 microgram/g wet weight after 8 days. Sclerotia subsequently produced after transfer of similar mats to soil contained 550 microgram/g wet weight.

Actinomycetales↗
PubMed1976

Effect of dicumarol on the growth of some soil microorganisms.

The effect of dicumarol on growth of selected soil bacteria: Azotobacter chroococcum, Arthrobacter globiformis, A. citreus and Bacillus megaterium was studied. The following minimum concentrations were inhibitory in vitro: Arthrobacter citreus--20 mug/ml., Bacillus megaterium--40 mug/ml., Azotobacter chroococcum--40 mug/ml. Arthrobacter globiformis--70 mug/ml. Cells of all microorganisms studied grown in the presence of dicumarol developed aberrant morphological forms.

Arthrobacter↗
PubMed1977

[The effect of biocides on the microflora of soils and their degradation. I. The selection of suitable biocides and ways of selective influences in soil-microorganisms (author's transl)].

The influence of 544 biocides on soil-microflora was investigated by a special plate-test and by a soil-test. Fungi were particularly sensitive to active substances. They were more inhibited by a greater number of substances, by lower concentrations and by a larger time-interval than bacteria. A differentiated sensitivity of fungi becomes apparent. The pseudomonads, a species of Agrobacter (AIA), flavobacteria and some coryneforme bacteria were relatively resistant. Actinomyces responded similar to fungi. The plate-test is suitable as preliminary test for the selection of substances retarding the degradation of straw. These organisms already favoured by treatments with active substance locate in higher quantities in such soils where the biological balance was disturbed in after the injection. Therefore, the effect of the active substance exceeds that of the injection. The displacement-effect by bacteria resistant to active substances and little active against cellulose plays a minor role in opposite to bacteria active against cellulose, because bacteria don't develop any homogeneous protective coat. A priority effect is therefore excluded.

Bacteria↗
PubMed1977

Degradation of carbaryl by soil microorganisms.

Four days after carbaryl-naphthyl-1-14C was mixed with soil from a field treated 6 months previously with 4 lb/A of the same insecticide, only 28% of the radiocarbon remained. Approximately 90% remained in soils with no history of pesticide applications. However, dissipation of the carbaryl-14C residues from the latter soils continued at a rather steady rate over a 120-day test period, whereas there was little dissipation after 4 days from the former. Consequently, the total 14C-residue levels were about the same, 15 to 20% of applied, when the last samples were taken. Carbaryl, per se, was the only apolar 14C-residue recovered from the soil and only small quantities, less than 2% of the amount applied, of extractable polar metabolites were encountered. Almost all of the terminal residues were unextractable from the soil with mixtures of acetone and water. Much of the loss of 14C-residues from the soil was attributed to the liberation of 14C-carbon dioxide as a result of microbial degradation of the naphthalene ring. Several fungal and bacterial isolates degraded carbaryl in the same manner as observed with soil incubations, but the rates of degradation were much slower.

Bacteria↗
PubMed1977

Ethylene production by soil microorganisms.

Ethylene-producing strains of Penicillium cyclopium and P. crustosum were isolated from soil. These isolates produced ethylene on a variety of carbon growth substrates including phenolic acids. The quantities of ethylene produced on the various substrates varied, and the subtrate-ethylene prosuction pattern for P. cyclopium strains differed significantly from that of P. crustosum strains.

Acetates↗
PubMed1976

Herbicides and soil microorganisms.

The production and usage of herbicides have increased dramatically in recent years. Consequently there is growing concern about the effects of these chemicals on the environment, particularly the possible long-term effects on soil fertility which may result from disturbance of the soil microflora. This review considers the recent developments in the study of the interactions between herbicides and microorganisms, and discusses the problems of evaluating the results of such studies with a view to determining or predicting possible short-term or long-term effects which may be of practical significance.

Adaptation, Physiological↗
PubMed1975

[Degradation of 14C, 3H, and 36Cl-labelled gamma-hexachlorocyclohexane by anaerobic soil microorganisms (author's transl)].

Up to 90% of the gamma-Hexachlorocyclohexane (gamma-HCH) applied to an anaerobic mixed bacterial flora enriched from an arable soil were degraded within 4-5 days. Degradation resulted in a rapid release of chloride and in formation of chlorine-free volatile metabolites. CO2 formation from the molecule was not detected. Investigations with 14C/3H- and 36Cl/3H double-labelled gamma-HCH indicated that the release of Cl and H did not occur in the ratio of 1:1. More Cl than H was split off. The volatile compounds contained more 14C than 3H. Gas chromatographic studies also showed the rapid decrease of gamma-HCH and the formation of several metabolities. gamma-Pentachlorocyclohexene was nto detected. Increasing O2-contents in the gas phase of cultures resulted in decreases of the compound's degradation. Release of chloride and of volatile metabolites were observed with O2 contents in the gas phase up to 5%. alpha-HCH was also, but more slowly as with gamma-HCH, degraded by the anaerobic mixed flora. Chloride was released and volatile, chlorine-free metabolites were found.

Anaerobiosis↗