scholarly journals Analysis of the Life Cycle of the Soil Saprophyte Bacillus cereus in Liquid Soil Extract and in Soil

2006 ◽  
Vol 72 (7) ◽  
pp. 4970-4977 ◽  
Author(s):  
Sébastien Vilain ◽  
Yun Luo ◽  
Michael B. Hildreth ◽  
Volker S. Brözel
Keyword(s):  
Organic Matter ◽  
Life Cycle ◽  
Bacillus Cereus ◽  
Agar Medium ◽  
Soil Extract ◽  
Associated Bacteria ◽  
Soil Microcosms ◽  
Agar Surface ◽  
Microscopic Inspection ◽  
Current Paradigm

ABSTRACT Bacillus is commonly isolated from soils, with organisms of Bacillus cereus sensu lato being prevalent. Knowledge of the ecology of B. cereus and other Bacillus species in soil is far from complete. While the older literature favors a model of growth on soil-associated organic matter, the current paradigm is that B. cereus sensu lato germinates and grows in association with animals or plants, resulting in either symbiotic or pathogenic interactions. An in terra approach to study soil-associated bacteria is described, using filter-sterilized soil-extracted soluble organic matter (SESOM) and artificial soil microcosms (ASM) saturated with SESOM. B. cereus ATCC 14579 displayed a life cycle, with the ability to germinate, grow, and subsequently sporulate in both the liquid SESOM extract and in ASM inserted into wells in agar medium. Cells grew in liquid SESOM without separating, forming multicellular structures that coalesced to form clumps and encasing the ensuing spores in an extracellular matrix. Bacillus was able to translocate from the point of inoculation through soil microcosms as shown by the emergence of outgrowths on the surrounding agar surface. Microscopic inspection revealed bundles of parallel chains inside the soil. The motility inhibitor l-ethionine failed to suppress outgrowth, ruling out translocation by a flagellar-mediated mechanism such as swimming or swarming. Bacillus subtilis subsp. subtilis Marburg and four Bacillus isolates taken at random from soils also displayed a life cycle in SESOM and ASM and were all able to translocate through ASM, even in presence of l-ethionine. These data indicate that B. cereus is a saprophytic bacterium that is able to grow in soil and furthermore that it is adapted to translocate by employing a multicellular mode of growth.

ANTIMICROBIAL ACTIVITIES OF METHANOL EXTRACT FROM UNIDENTIFIED SPONGE ASSOCIATED BACTERIA IN LEMUKUTAN ISLAND, KALIMANTAN BARAT

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar
Keyword(s):  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Agar Medium ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Associated Bacteria ◽  
Minimum Inhibitory Concentrations ◽  
Sponge Associated Bacteria

<p>The increase of issues on the antibiotics resistant pathogenic bacteria has triggered high exploration for new antimicrobial compounds. One of the potential sources is sponge-associated bacteria. The aim of this study was to get sponge-associated bacteria extract containing antimicrobial activities. On the basis screening of antimicrobial activity using by streaking on agar medium, there were two potential isolates with antimicrobial activities namely LCS1 and LCS2. The two isolates were cultivated,then secondary metabolite product were extracted using methanol as a solvent. Minimum inhibitory concentrations (MICs) of extract LCS 1 were 1,000 μg/well for S. aureus, 950 μg/well for Salmonella sp.and 800 μg/well for Bacillus subtilis. Minimum inhibitory concentrations of extract LCS 2 were 500 μg/well for S. aureus, 1,050 μg/well for Salmonella sp., 750 μg/well for Bacillus subtilis, 350 μg/well for P. aeruginosa, 750 μg/sumur terhadap B. subtilis. Based on the MIC values, the two assay extracts have a relatively low antimicrobial activity.</p> <p>Keywords:Antimicrobial,Sponges associated bacteria,MICs</p>

THE INFLUENCE OF SOIL AND ROOT EXTRACTS ON THE ASSOCIATIVE GROWTH OF SELECTED SOIL BACTERIA

1963 ◽  
Vol 9 (2) ◽  
pp. 187-197 ◽  
Author(s):  
E. C. S. Chan ◽  
H. Katznelson ◽  
J. W. Rouatt
Keyword(s):  
Mixed Culture ◽  
Soil Bacteria ◽  
Agar Medium ◽  
Soil Extract ◽  
Antagonistic Effect ◽  
Pseudomonas Sp ◽  
Population Changes ◽  
Agrobacterium Radiobacter ◽  
Root Extracts ◽  
Wheat Population

These studies are concerned with the growth interrelationships of mixed cultures of five soil organisms in soil extract and root extracts of 2-, 4-, and 8-week-old oats, soybeans, and wheat. Population changes of Agrobacterium radiobacter, Arthrobacter citreus, Azotobacter chroococcum, Bacillus cereus, and a Pseudomonas sp. in pure and mixed culture were followed by plating on selective media. B. cereus and A. chroococcum grew poorly alone or in mixed culture in the extracts. In soil extract, A. citreus predominated over, or was nearly equal in number to, the Gram-negative forms (Pseudomonas and Agrobacterium). In root extracts, Pseudomonas sp. always predominated over A. citreus in mixed culture. A. radiobacter was inhibited in mature root extracts (8-week-old plants) although in pure culture it recovered after a period. An antagonistic effect of Pseudomonas sp. on A. chroococcum plated on nitrogen-free agar medium was found to be related to the kind of agar used.

First Report of the Earthworm Pontoscolex corethrurus (Müller, 1857) from Punjab, India

2018 ◽  
Vol 68 ◽  
pp. 1-8 ◽  
Author(s):  
Sharanpreet Singh ◽  
Jaswinder Singh ◽  
Ayushi Sharma ◽  
Adarsh Pal Vig ◽  
Shakoor Ahmed
Keyword(s):  
Organic Matter ◽  
Life Cycle ◽  
High Efficiency ◽  
Economic Importance ◽  
Edaphic Factors ◽  
Pontoscolex Corethrurus ◽  
Wide Range ◽  
First Time ◽  
Poor Soil ◽  
German Naturalist

The earthwormPontoscolex corethrurus(Müller, 1857) is reported for the first time from Punjab, India. This species was first described by German naturalist Fritz Müller in 1857 from Santa Catarina state of Brazil. It is commonly found in gardens, cropland and fallowlands. It tolerates wide range of climatic and edaphic factors due to its endogeic ecological category.P. corethrurushas high efficiency for organic matter assimilation and has ability to live in new habitat due to which it can survive even in very poor soil. The life cycle of this species is well documented and this species has economic importance due to its use in waste management.

PROPRIETES PHYSICO-CHIMIQUES ET MINERALOGIQUES DES SOLS DES FORETS DE CHENES DE L’OUEST DE L’IRAN

1982 ◽  
Vol 62 (1) ◽  
pp. 39-48 ◽  
Author(s):  
H. RAFAHI
Keyword(s):  
Organic Matter ◽  
Clay Mineral ◽  
Soil Surface ◽  
Soil Extract ◽  
Exchange Capacity ◽  
The Other ◽  
Chlorine Ions ◽  
Deep Soils ◽  
Depth Horizon ◽  
Quercus Infectoria

Most of the soils studied are non-evolved. The other soils of the area that can be distinguished are calcareous brown soils, sierozems and erosion soils. The soils are low in organic matter. The carbonate, varying from 0.4 to 46.3%, tends to increase with depth. Horizon of accumulation of carbonate (in the sierozems) is found between 30 and 100 cm from the soil surface. Sulfate exceeds chlorine ions in the soil extract. The salinity does not exist in these soils. The exchange capacity varies from 4.7 to 29.4 meq/100 g of soil. The dominant clay mineral in some of these soils is vermiculite. In the forests of western Iran, Quercus persica and Quercus saii generally occupy calcareous, poor and rather deep soils, whereas Quercus infectoria is usually grown on the less calcareous, rich and deep soils.

The life history of Branchinecta mackini Dexter (Crustacea: Anostraca) in an argillotrophic lake of Alberta

1977 ◽  
Vol 55 (1) ◽  
pp. 161-168 ◽  
Author(s):  
Graham R. Daborn
Keyword(s):  
Organic Matter ◽  
Life History ◽  
Life Cycle ◽  
Growth Rates ◽  
Dry Weight ◽  
Fairy Shrimp ◽  
Maximum Biomass ◽  
History Of ◽  
Mean Size

The life history of B. mackini was studied in a large argillotrophic lake during 1970–1972. Hatching began immediately after spring thaw and was terminated by rising salinity 10 days to 2 weeks later. Growth rates reached maxima of 1 mm/day at 4 weeks of age and then declined as mean size approached 22–23 mm at 7–8 weeks. Clutch sizes varied as a function of female length. Maximum biomass of 580 mg dry weight/m2 (2700 cal/m2) was reached in late May, of which 3.9% per day was consumed by B. gigas. Source of the energy is presumed to be a bacteria – organic matter complex associated with suspended particles. Life cycle details are compared with other fairy shrimp species and the role of B. mackini in the community is discussed.

scholarly journals Two different microbial communities did not cause differences in occlusion of particulate organic matter in a sandy agricultural soil

2016 ◽  
Author(s):  
Frederick Büks ◽  
Philip Rebensburg ◽  
Peter Lentzsch ◽  
Martin Kaupenjohann
Keyword(s):  
Organic Matter ◽  
Microbial Communities ◽  
Particulate Organic Matter ◽  
Agricultural Soil ◽  
Agricultural Soils ◽  
Soil Aggregates ◽  
Soil Extract ◽  
Microbial Life ◽  
Physico Chemical ◽  
Airborne Microbes

Abstract. Apart from physico-chemical interactions between soil components, microbial life is assumed to be an important factor of soil structure forming processes. Bacterial exudates, the entanglement by fungal hypae and bacterial pseudomycelia as well as fungal glomalin are supposed to provide the occlusion of particulate organic matter (POM) through aggregation of soil particles. This work investigates the resilience of POM occlusion in face of different microbial communities under controlled environmental conditions. We hypothesized that the formation of different communities would cause different grades of POM occlusion. For this purpose samples of a sterile sandy agricultural soil were incubated for 76 days in bioreactors. Particles of pyrochar from pine wood were added as POM analogue. One variant was inoculated with a native soil extract, whereas the control was infected by airborne microbes. A second control soil remained non-incubated. During the incubation, soil samples were taken for taxon-specific qPCR to determine the abundance of Eubacteria, Fungi, Archaea, Acidobacteria, Actinobacteria, α-Proteobacteria and β-Proteobacteria. After the incubation soil aggregates (100–2000 μm) were collected by sieving and disaggregated using ultrasound to subject the released POM to an analysis of organic carbon (OC). Our results show, that the eubacterial DNA of both incubated variants reached a similar concentration after 51 days. However, the structural composition of the two communities was completely different. The soil-born variant was dominated by Acidobacteria, Actinobacteria and an additional fungal population, whereas the air-born variant mainly contained β-Proteobacteria. Both variants showed a strong occlusion of POM into aggregates during the incubation. Yet, despite the different population structure, there were only marginal differences in the release of POM along with the successive destruction of soil aggregates by ultrasonication. This leads to the tentative assumption that POM occlusion in agricultural soils could be resilient in face of changing microbial communities.

ANTIMICROBIAL ACTIVITIES OF METHANOL EXTRACT FROM UNIDENTIFIED SPONGE ASSOCIATED BACTERIA IN LEMUKUTAN ISLAND, KALIMANTAN BARAT

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar
Keyword(s):  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Agar Medium ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Associated Bacteria ◽  
Minimum Inhibitory Concentrations ◽  
Sponge Associated Bacteria

The increase of issues on the antibiotics resistant pathogenic bacteria has triggered high exploration for new antimicrobial compounds. One of the potential sources is sponge-associated bacteria. The aim of this study was to get sponge-associated bacteria extract containing antimicrobial activities. On the basis screening of antimicrobial activity using by streaking on agar medium, there were two potential isolates with antimicrobial activities namely LCS1 and LCS2. The two isolates were cultivated,then secondary metabolite product were extracted using methanol as a solvent. Minimum inhibitory concentrations (MICs) of extract LCS 1 were 1,000 μg/well for S. aureus, 950 μg/well for Salmonella sp.and 800 μg/well for Bacillus subtilis. Minimum inhibitory concentrations of extract LCS 2 were 500 μg/well for S. aureus, 1,050 μg/well for Salmonella sp., 750 μg/well for Bacillus subtilis, 350 μg/well for P. aeruginosa, 750 μg/sumur terhadap B. subtilis. Based on the MIC values, the two assay extracts have a relatively low antimicrobial activity. Keywords:Antimicrobial,Sponges associated bacteria,MICs

Antifungal properties exhibited by bacteria isolated from agriculturally cultivable soils and their antagonistic nature towards fungal phytopathogen suppression

2016 ◽  
Vol 35 (1) ◽  
Author(s):  
Ch. Usha Rani ◽  
Priyanka ◽  
A. Srinivasa Rao
Keyword(s):  
Bacillus Cereus ◽  
Biochemical Characterization ◽  
Rhizosphere Soil ◽  
Agar Medium ◽  
Chitinolytic Activity ◽  
Culture Methods ◽  
Bacterial Cultures ◽  
Nutrient Agar Medium ◽  
Fungal Antagonism ◽  
Fungal Phytopathogen

Soil samples collected from rhizosphere soil, cultivable field soil, Rhizoplane soil of paddy plants and were used to isolate bacteria by culture methods of which thirty two bacterial cultures were identified with diverse colony characteristics on nutrient agar medium and biochemical characterization. Sixteen bacterial isolates were selected for screening fungal antagonism on PDA and were further tested against <italic>Fusarium</italic> and <italic>Rhizoctonia species.</italic> In this study, two <italic>Pseudomonas strains</italic> (RB15, RB30) and <italic>Bacillus cereus</italic> (RB13) were cyanogen producers. Both strains of <italic>Pseudomonas</italic> RB15 and RB30 and <italic>Bacillus cereus</italic> (RB13) were also siderophore producers. Only three isolates showed chitinolytic activity; <italic>Serratia marcesens (RB24), Bacillus cereus (RB13) and Enterobacter cancerogenus</italic> (RB17).

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