QUALITATIVE STUDIES OF SOIL MICRO-ORGANISMS: II. A SURVEY OF THE BACTERIAL FLORA OF SOILS DIFFERING IN FERTILITY

1938 ◽  
Vol 16c (4) ◽  
pp. 162-173 ◽  
Author(s):  
C. B. Taylor ◽  
A. G. Lochhead
Keyword(s):  
Bacterial Flora ◽  
General Character ◽  
Relative Incidence ◽  
Single Culture ◽  
Different Types ◽  
Selective Basis ◽  
Qualitative Nature ◽  
Micro Organisms ◽  
Bacterial Groups ◽  
Biochemical Action

Investigations were made, on a non-selective basis, of the qualitative nature and relative incidence of the different types of the bacterial flora of three soils differing in fertility. The organisms were classified into eight groups. Non-spore-forming short rods, of which five groups were recognized, comprised nearly 90% of all types. Gram-negative short rods formed the most prevalent single group, rather more numerous than Gram-positive short rods. Gram-variable short rods, coccoid rods and pleomorphic rods (Bact. globiforme) were regarded as definite groups. Cocci, non-spore-forming long rods and spore-formers were less prominent soil types.In spite of unequal productivity, the soils showed no outstanding differences in the relative incidence of the bacterial groups. Certain groups showed some indication of seasonal and cropping effect. The results suggest that the general character of the autochthonous (indigenous) soil flora is relatively uniform in soil of definite type, even though productivity may be greatly altered by manurial treatment.The predominant soil bacteria appear relatively inactive in single culture. Moreover considerable divergence in biochemical action was shown by apparently closely related forms. It is suggested that the bacterial flora is relatively unstable physiologically, with considerable adaptability, and that the functions of the different species are exercised most fully only under conditions of association.

QUALITATIVE STUDIES OF SOIL MICRO-ORGANISMS: III. INFLUENCE OF PLANT GROWTH ON THE CHARACTER OF THE BACTERIAL FLORA

1940 ◽  
Vol 18c (2) ◽  
pp. 42-53 ◽  
Author(s):  
A. G. Lochhead
Keyword(s):  
Physiological Activity ◽  
Bacterial Flora ◽  
Soil Microflora ◽  
Pronounced Increase ◽  
The Family ◽  
Qualitative Nature ◽  
Selective Plating ◽  
Genus Corynebacterium ◽  
Micro Organisms

Comparative studies of the relative incidence of bacterial types occurring in the rhizosphere of different plants and in control soils indicated that the qualitative nature of the soil microflora is markedly influenced by the growing plant. In the rhizosphere Gram-negative rods are proportionately increased while Gram-positive rods, coccoid rods, and spore-forming types are relatively less abundant.The majority of bacteria isolated from soil by non-selective plating are forms included in the family Proactinomycetaceae (Jensen's classification). Of these by far the largest group consists of members of the genus Corynebacterium. In the rhizosphere proactinomycetes as a whole are relatively less abundant, with the Corynebacterium (non-motile) group likewise depressed. However, closely related motile forms classed as Mycoplana are preferentially stimulated.In the rhizosphere the bacteria show definitely greater physiological activity than in soil distant from the plant. Not only is there a notably greater proportion of motile forms, and a pronounced increase in the incidence of chromogenic types, but also a higher incidence of liquefying bacteria and of those able to affect glucose.A comparison of the rhizosphere of certain plant varieties resistant and susceptible respectively to soil-borne disease showed differences of a qualitative nature in the bacterial flora suggestive of a greater "rhizosphere effect" in the case of the susceptible varieties studied. Results point to the possibility that resistance may be associated with a selective action of root excretions on the saprophytic soil microflora.

scholarly journals Some chemical and bacterial characteristics of bottom deposits from lakes and estuaries

1953 ◽  
Vol 51 (2) ◽  
pp. 185-194 ◽  
Author(s):  
L. A. Allen ◽  
J. Grindley ◽  
Eileen Brooks
Keyword(s):  
Bacteriological Examination ◽  
Surface Layers ◽  
Digested Sludge ◽  
Faecal Pollution ◽  
Bottom Deposits ◽  
Low Concentrations ◽  
Different Types ◽  
Different Depths ◽  
Micro Organisms ◽  
Reducing Bacteria

Chemical and bacteriological examination of muds from sources differing widely in the degree of pollution to which they were subject showed great differences in the contents of carbon, nitrogen and sulphide. These differences were not correlated with differences in the severity of faecal pollution. The amount of organic matter available for growth of micro-organisms in the mud of different depths was not reflected in the figures for organic carbon. A convenient index of this factor was obtained by measuring the volume of gas evolved during anaerobic digestion over a prolonged period of incubation. The rate of evolution was increased by the addition of an inoculum of digested sludge from a sewage works.Sulphate-reducing bacteria appeared to be of two different types. In samples of mud from fresh-water lakes much higher counts were usually obtained in a medium containing comparatively low concentrations of inorganic salts and of lactate than in a medium containing much higher concentrations of these constituents. In samples from locations where conditions were more saline the reverse was usually true.Counts of Bact. coli and of Strep, faecalis together probably constitute the best index of faecal pollution in the examination of samples of mud. These organisms are, however, largely confined to the surface layers.

Interactions between micro-organisms on skin

1980 ◽  
Vol 79 (1-3) ◽  
pp. 185-191
Author(s):  
W. C. Noble
Keyword(s):  
Skin Lesion ◽  
Secondary Metabolites ◽  
Bacterial Flora ◽  
Antibiotic Resistant ◽  
General Terms ◽  
Micro Organisms ◽  
Selection Of

SynopsisThe mechanisms of interaction are discussed in general terms; this is followed by a review of interaction which may occur in tinea paedis.The production of penicillin-like and other antibiotics by dermatophyte fungi in lesions of athletes foot may result in the selection of an antibiotic-resistant bacterial flora which, perhaps by production of antibiotic or other secondary metabolites, can reduce the viability of the fungi. The effect on the host is to bring about a change from a fungal skin lesion which is dry and scaly to a bacterial lesion which is macerated and malodorous.

scholarly journals Phylogenomic Analysis and Predicted Physiological Role of the Proton-Translocating NADH:Quinone Oxidoreductase (Complex I) Across Bacteria

mBio ◽  
2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Melanie A. Spero ◽  
Frank O. Aylward ◽  
Cameron R. Currie ◽  
Timothy J. Donohue
Keyword(s):  
Respiratory Chain ◽  
Complex I ◽  
Bacterial Genomes ◽  
Bacterial Physiology ◽  
Nadh:Quinone Oxidoreductase ◽  
Different Types ◽  
Respiratory Chains ◽  
Bacterial Groups ◽  
Bacterial Complex

ABSTRACTThe proton-translocating NADH:quinone oxidoreductase (complex I) is a multisubunit integral membrane enzyme found in the respiratory chains of both bacteria and eukaryotic organelles. Although much research has focused on the enzyme's central role in the mitochondrial respiratory chain, comparatively little is known about its role in the diverse energetic lifestyles of different bacteria. Here, we used a phylogenomic approach to better understand the distribution of complex I across bacteria, the evolution of this enzyme, and its potential roles in shaping the physiology of different bacterial groups. By surveying 970 representative bacterial genomes, we predict complex I to be present in ~50% of bacteria. While this includes bacteria with a wide range of energetic schemes, the presence of complex I is associated with specific lifestyles, including aerobic respiration and specific types of phototrophy (bacteria with only a type II reaction center). A phylogeny of bacterial complex I revealed five main clades of enzymes whose evolution is largely congruent with the evolution of the bacterial groups that encode complex I. A notable exception includes the gammaproteobacteria, whose members encode one of two distantly related complex I enzymes predicted to participate in different types of respiratory chains (aerobic versus anaerobic). Comparative genomic analyses suggest a broad role for complex I in reoxidizing NADH produced from various catabolic reactions, including the tricarboxylic acid (TCA) cycle and fatty acid beta-oxidation. Together, these findings suggest diverse roles for complex I across bacteria and highlight the importance of this enzyme in shaping diverse physiologies across the bacterial domain.IMPORTANCELiving systems use conserved energy currencies, including a proton motive force (PMF), NADH, and ATP. The respiratory chain enzyme, complex I, connects these energy currencies by using NADH produced during nutrient breakdown to generate a PMF, which is subsequently used for ATP synthesis. Our goal is to better understand the role of complex I in bacteria, whose energetic diversity allows us to view its function in a range of biological contexts. We analyzed sequenced bacterial genomes to predict the presence, evolution, and function of complex I in bacteria. We identified five main classes of bacterial complex I and predict that different classes participate in different types of respiratory chains (aerobic and anaerobic). We also predict that complex I helps maintain a cellular redox state by reoxidizing NADH produced from central metabolism. Our findings suggest diverse roles for complex I in bacterial physiology, highlighting the need for future laboratory-based studies.

Effect of a pesticide pentachlorophenol on soil microflora. III. Growth rates as an index of pesticide resistance of bacterial groups isolated from soil

1987 ◽  
Vol 33 (9) ◽  
pp. 819-822 ◽  
Author(s):  
Kyo Sato
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Bacterial Species ◽  
Bacterial Flora ◽  
Soil Microflora ◽  
Pesticide Resistance ◽  
Relative Growth ◽  
Bacterial Groups

Pentachlorophenol resistance was investigated in bacteria isolated from glycine- or water-percolated soils where the bacterial flora was modified by the addition of pentachloropenol. The strains isolated from the water-percolated soil amended with PCP had the highest resistance, and the addition of glycine to the percolated soil weakened the resistance. The strains from the glycine-percolated soil without pentachlorophenol had a medium degree of resistance, and the resistance of the strains from the water-percolated soil without PCP was the lowest. The bacterial groups were sorted taxonomically; differences in pentachloropenol resistance were correlated with taxonomic groupings. Relative growth rate in the presence of pentachlorophenol was proposed as a useful means to distinguish among the bacterial species.

THE INTERACTION OF HIGHER PLANTS AND SOIL MICRO-ORGANISMS: I. MICROBIAL POPULATION OF RHIZOSPHERE OF SEEDLINGS OF CERTAIN CULTIVATED PLANTS

1940 ◽  
Vol 18c (7) ◽  
pp. 307-317 ◽  
Author(s):  
M. I. Timonin
Keyword(s):  
New Species ◽  
Relative Abundance ◽  
Microbial Population ◽  
Higher Plants ◽  
Cultivated Plants ◽  
Plating Method ◽  
Different Types ◽  
Micro Organisms ◽  
A New Species

The microbial population in the rhizosphere of wheat, oats, alfalfa, and peas was studied and the relative abundance of different types of micro-organisms recorded. By means of the plating method it was found that bacteria and actinomycetes were 7 to 71 times greater in the rhizosphere than in the soil distant from the roots, whereas fungi were but 0.75 to 3.1 times more numerous.Different varieties of plants affected the activity of the various groups of soil micro-organisms differently. Thus fungi were more numerous in the rhizosphere of oats, and bacteria in the rhizosphere of alfalfa. Seventeen genera of fungi were represented in isolates from the rhizosphere of seedlings and the soil distant from the roots. However, no marked difference was observed in the types isolated from the rhizosphere of different varieties of seedlings. A fungus isolated from the rhizosphere of alfalfa proved to be a new species and the genus Spicularia Persoon was amended to include it.

Numerical Simulation on Mass Transport in a Microchannel Bioreactor for Co-culture Applications

2006 ◽  
Vol 129 (3) ◽  
pp. 365-373 ◽  
Author(s):  
Yan Zeng ◽  
Thong-See Lee ◽  
Peng Yu ◽  
Hong-Tong Low
Keyword(s):  
Mass Transport ◽  
Three Dimensional ◽  
Culture Cell ◽  
Inlet Concentration ◽  
Single Culture ◽  
Different Types ◽  
Flux Parameter ◽  
Combined Parameters ◽  
Axial Concentration ◽  
Cell Base

Microchannel bioreactors have applications for manipulating and investigating the fluid microenvironment on cell growth and functions in either single culture or co-culture. This study considers two different types of cells distributed randomly as a co-culture at the base of a microchannel bioreactor: absorption cells, which only consume species based on the Michaelis-Menten process, and release cells, which secrete species, assuming zeroth order reaction, to support the absorption cells. The species concentrations at the co-culture cell base are computed from a three-dimensional numerical flow-model incorporating mass transport. Combined dimensionless parameters are proposed for the co-culture system, developed from a simplified analysis under the condition of decreasing axial-concentration. The numerical results of species concentration at the co-culture cell-base are approximately correlated by the combined parameters under the condition of positive flux-parameter. Based on the correlated results, the critical value of the inlet concentration is determined, which depends on the effective microchannel length. For the flow to develop to the critical inlet concentration, an upstream length consisting only of release cells is needed; this upstream length is determined from an analytical solution. The generalized results may find applications in analyzing the mass transport requirements in a co-culture microchannel bioreactor.

scholarly journals Isolasi Dan Identifikasi Bakteri Yang Terdapat Pada Saluran Pencernaan Ikan Gurami (Osphronemus gouramy) Dengan Pemberian Pakan Komersil Yang Berbeda [Isolation And Identification Of Bacterial In The Digestive Organ Of Gurami Fish (Osphronemus gouramy) With Different Commercial Feed]

2019 ◽  
Vol 6 (1) ◽  
pp. 87
Author(s):  
Franch Dalahi, Sri Subekti, Agustono
Keyword(s):  
Digestive Tract ◽  
Eating Habits ◽  
Bacterial Flora ◽  
Natural Food ◽  
Pseudomonas Sp ◽  
Isolation And Identification ◽  
Growth And Survival ◽  
Commercial Feed ◽  
Different Types ◽  
Identification Of Bacteria

Abstract Based on the food habits, gurami is omnivorous fish that feed herbivorous carp tend consists of natural food and artificial feed (pellets). The feed is needed to support the growth and survival of Gurami. If feed is given in accordance with the eating habits of Gurami and contain high nutritional Gurami can then growth accelerated faster. Some types of bacteria found in the digestive tract of animals has an important role in order to improve feed utilization, fish health, and environmental quality improvement and microorganisms. In addition, some bacterial flora in the gastrointestinal tract plays an important role and produce several types of enzymes in the digestive tract may contribute to the metabolism of the host. The purpose of this study was to determine the bacteria in the digestive tract of Gurami (Osphronemus gouramy) were given three different types of commercial feed. This study begins with a sampling of Gurami (Oshpronemus gouramy) of maintenance in the Faculty of Fisheries and Marine at Airlangga University in Surabaya and then do stage isolation and identification of bacteria in laboratory bacteria and Microbiology, Faculty of Veterinary Medicine, Airlangga University Surabaya. This study was conducted in July 2013. This research is a descriptive study, the method of solving the problem by describing the subject matter into a form that is easy to understand and based on facts. Results of research on gurami fish that given by three different types of commercial feed, there are two types of bacteria that dominate in the digestive tract of carp, the Pseudomonas sp. and Serratia sp. Both types of bacteria has the potential to help the digestive system of gurami fish. The result of this research are need for further research using the bacterium Pseudomonas sp. and Serratia sp. as probiotics.

scholarly journals Applicability of Escherichia Coli As an Indicator for Assessing Quality of Disinfectants and Antiseptic During the COVID-19 Pandemic

2021 ◽  
Author(s):  
Reza Ali Fallahzadeh ◽  
Fariborz Omidi ◽  
Davoud Ghadirian ◽  
Azimeh Fallahzadeh ◽  
Mohammad Reza Nafisi
Keyword(s):  
Test Tube ◽  
Laboratory Method ◽  
Gram Negative Bacteria ◽  
Optimum Conditions ◽  
Gram Negative ◽  
E Coli ◽  
Different Types ◽  
Micro Organisms ◽  
Required Quality

Introduction: The application of disinfectant agents is a common way to fight against micro-organisms. Although there are different types of disinfectant agents to fight COVID-19, many of them do not have the required quality and efficiency. The present work was aimed to evaluate the quality of the available disinfectant agents using gram-negative E. coli bacteria. Materials and Methods: In the laboratory phase of the research, the gram-negative E. coli bacteria were used to evaluate the quality of disinfectants. According to the proposed laboratory method, microbial kit was prepared and used to evaluate the performance of disinfectants. Results: Based on the obtained results, 1.0 mL of microbial suspension in the test tube, as microbial kit, is used for quality assessment of the disinfectants. Also, based on the results and considering the optimum conditions, in case of growth of microorganisms, the quality of disinfectant is evaluated as unfavorable, and in the absence of growth of microorganisms, the quality of disinfectant is considered appropriate in terms of its effect on gram-negative bacteria and weaker microorganisms. Conclusion: Based on the obtained results, E. coli can be used as a reliable indicator for assessing the quality of the disinfectant agents used against COVID 19.

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