A microbial interaction involving combined mutualism and inhibition

1968 ◽  
Vol 14 (4) ◽  
pp. 491-492 ◽  
Author(s):  
H. T. Yeoh ◽  
H. R. Bungay ◽  
N. R. Krieg
Keyword(s):  
Mixed Culture ◽  
Pure Culture ◽  
Continuous Flow ◽  
Proteolytic Enzymes ◽  
Defined Medium ◽  
The Other ◽  
Bacillus Polymyxa ◽  
Microbial Interaction ◽  
Proteus Vulgaris ◽  
Vitamin Requirement

A defined medium deficient in both niacin and biotin supported neither Proteus vulgaris nor Bacillus polymyxa in pure culture, but a mixed culture grew well. Presumably each can supply a vitamin requirement for the other. Continuous flow cultivation of mixed cultures exhibited oscillatory population levels of each species. P. vulgaris produced an inhibitor which accumulated to inhibit growth of B. polymyxa, and the vitamin interdependency caused the former to also cease growing. After continued pumping diluted the inhibitor, growth resumed. The inhibitor seems to be a protein, because proteolytic enzymes added to the culture gave higher, non-oscillatory population levels.

Impact of Transfaunation of Rumen Ciliate Cultures on Physical Examination, Selected Serum Parameters and Milk Profile in Defaunated Lactating Dairy Goats

2020 ◽  
Keyword(s):  
Physical Examination ◽  
Mixed Culture ◽  
Pure Culture ◽  
Milk Fat ◽  
Mixed Cultures ◽  
Dairy Goats ◽  
Serum Parameters ◽  
Native Breed ◽  
Culture Duration ◽  
Inorganic Phosphorous

Rumen ciliates still have mysterious secrets and influences in ruminants. This study investigated the effect of transfaunation of pure and mixed cultures of rumen ciliates on physical clinical examination, selected serum parameters and milk profile in defaunated lactating dairy goats. A number of 8 Baladi native breed goats were randomly classified into two groups each one containing 4 goats. Pure culture group was transfaunated with 6 ml of pure culture of Holotricha spp., while mixed culture group was transfaunated with 6 ml of mixed culture of 81.85% Holotricha and 18.15% Ophryoscolex spp. once weekly for three consecutive weeks, after defaunation of both groups using 30 ml of 8% SLS for two consecutive days. Serum and milk samples were collected weekly for three successive weeks to study effect of type of ciliate culture, duration of transfaunation and their interaction. Results revealed that transfaunation of pure and mixed cultures of rumen ciliates had no effect on physical examination with minimal non-significant improvement of calcium, inorganic phosphorous, total protein and globulin in serum of defaunated goats. Transfaunation of pure or mixed cultures of rumen ciliates within three weeks could not improve significantly decreased milk fat % of defaunated goats without any effect on other measured milk profile parameters. It is concluded that further investigations on transfaunation without prior defaunation should be performed using different pure and mixed cultures of rumen ciliates for therapeutic and productive purposes.

Biodegradation of chlorophenols by immobilized pure-culture microorganisms

1996 ◽  
Vol 34 (10) ◽  
pp. 67-72 ◽  
Author(s):  
Lu Chih-Jen ◽  
Lee Chi-Mei ◽  
Huang Chiou-Zong
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pseudomonas Putida ◽  
Pure Culture ◽  
The Other ◽  
Batch Reactors ◽  
Agrobacterium Radiobacter ◽  
Culture Cells ◽  
Lag Period

The biodegradation of phenol and chlorophenols by immobilized pure-culture cells was conducted by a series of batch reactors. The microorganisms used in this study were Pseudomonas putida, Psuedomonas testosteroni, Pseudomonas aeruginosa, and Agrobacterium radiobacter. All four species showed the ortho-cleavage pathway to metabolize chlorophenols. Among the four species, P. testosteroni, P. putida, and P. aeruginosa could effectively remove phenol at 200 mg/l. P. testosteroni could effectively remove 2-chlorophenol at 10mg/l. However, the other three species, P. putida, P. aeruginosa, and A. radiobacter, could not effectively remove 2-chlorophenol. Although 3-chlorophenol is a recalcitrant compound, P. testosteroni also could rapidly metabolize 3-chlorophenol at 10 mg/l. The removal of 4-chlorophenol at 10 mg/l by P. testosteroni reached 98% within one day. P. aeruginosa and A. radiobacter also could metabolize 4-chlorophenol after 2 and 7 days of lag period, respectively.

scholarly journals Methods to extract the exopolymeric matrix from biofilms: a comparative study

1999 ◽  
Vol 39 (7) ◽  
pp. 243-250 ◽  
Author(s):  
Joana Azeredo ◽  
Valentina Lazarova ◽  
Rosário Oliveira
Keyword(s):  
Organic Carbon ◽  
Comparative Study ◽  
Mixed Culture ◽  
Pure Culture ◽  
Cell Walls ◽  
Extraction Method ◽  
Extraction Methods ◽  
Suitable Method ◽  
The Matrix ◽  
Biofilm Matrix

To study the composition of a biofilm a previous extraction method is required to separate cells from the matrix. There are several methods reported in the literature; however they are not efficient or promote leakage of intracellular material. In this work several extraction methods were assayed in mixed culture and pure culture biofilms and their efficiency was evaluated by the amount of organic carbon, proteins and intracellular material extracted. The results showed that the extraction with glutaraldehyde 3% (w/v) was the most suitable method, extracting great amounts of organic carbon without promoting cell lysis or permeabilization. Glutaraldehyde is a bifunctional reagent that binds to cell walls avoiding their permeabilization and the biofilm matrix is solubilized in the solution.

scholarly journals Enzymes for Leather Processing: Effect on Pickling and Chroming

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1480
Author(s):  
Renata Biškauskaitė ◽  
Violeta Valeikienė ◽  
Virgilijus Valeika
Keyword(s):  
Mechanical Properties ◽  
Acidic Medium ◽  
Proteolytic Enzymes ◽  
Relative Elongation ◽  
The Other ◽  
Shrinkage Temperature ◽  
Processing Effect ◽  
Leather Processing ◽  
Production Processes ◽  
Pickling Process

Recently, increasing attention has been paid to the application of enzymes in a wide variety of leather production processes. The aim of the present study was to investigate the action of enzymatic pickling on derma’s collagen and the influence of this action on subsequent processes and properties of chromed and finished leather. The application of active in acidic medium proteolytic enzymes in the pickling process led to an additional impact on derma structure: collagen was more strongly affected and the porosity of the pelt dermis was reduced, but the hide became more thermally stable. The enzymatically pickled pelt bonded more chromium and reached higher shrinkage temperature while chroming; dyes penetrated deeper; such leather bonded more fatliquors. On the other hand, the action of enzymes worsened the physical–mechanical properties of the leather, as the experimental leather was weaker than the conventional one. The first was characterised by weaker grain layer and had significantly higher relative elongation. Therefore, as some properties improve and others worsen during such a process, the application of every enzyme should be carefully investigated and optimized to produce a leather with defined properties.

scholarly journals Conditions Favoring Proliferation of Glycogen Accumulating Organisms for Excess Biological Carbon Removal in Treating Nutrient Deficient Wastewater

2017 ◽  
Vol 61 (3) ◽  
pp. 149 ◽  
Author(s):  
Andrea Jobbágy ◽  
Bernadett Kiss ◽  
Vince Bakos
Keyword(s):  
Activated Sludge ◽  
Continuous Flow ◽  
The Other ◽  
N Availability ◽  
Filamentous Bacteria ◽  
Severe Deficiency ◽  
And Performance ◽  
Experimental Stage ◽  
Activated Sludge Systems ◽  
P Sources

Impact of marginal availability and severe deficiency of nitrogen on the growth of glycogen accumulating organisms (GAOs) and performance of anaerobic/aerobic activated sludge systems treating nutrient deficient wastewater was investigated at marginal availability and severe deficiency of phosphorus. Two continuous-flow lab-scale systems were operated simultaneously fed by model winery wastewater, one with marginal availability and the other one at severe deficiency of nitrogen. In the second experimental stage, marginal availability of P was converted into severe deficiency by interrupting external dosing.Common practice of dosing N- and P-sources to marginal availability caused enhanced proliferation of filamentous bacteria leading to poor biomass settling and instable operation. At marginal N-availability accumulation of GAOs started when conditions became deficient for phosphorus. In severe lack of nitrogen GAOs overgrew filaments, and outcompeted phosphorous accumulating organisms (PAOs) initially present in the seed. Stable and good performance could be maintained even after withdrawal of phosphorous dosing.

Experimentelle Rotlauf- und Streptokokken-Endokarditis bei der Ratte

1971 ◽  
Vol 8 (2) ◽  
pp. 146-174 ◽  
Author(s):  
A. Kast ◽  
M. Herbst ◽  
L. Stoll
Keyword(s):  
Endothelial Cells ◽  
Mixed Culture ◽  
Bacterial Endocarditis ◽  
Mixed Cultures ◽  
The Other ◽  
Male Rats ◽  
Bacterial Colonisation ◽  
Intravenous Injections ◽  
Single And Mixed Cultures

The ability of intravenous injections of single and mixed cultures of streptococci of types A, C, D, E, G, and N, of S. viridans and of E. rhusiopathiae of serotypes A and B, to cause endocarditis in rats was tested. A mixed culture of three strains of Erysipelothrix was particularly effective, especially in male rats, whereas in all the other experiments, bacterial endocarditis seldom occurred. The endocarditis was a consequence of vasculitis and myocarditis. In most cases of valvular endocarditis subendothelial edema caused detachment of endothelial cells and provided the environment for bacterial colonisation of the valves.

scholarly journals Rubber gloves biodegradation by a consortium, mixed culture and pure culture isolated from soil samples

2018 ◽  
Vol 49 (3) ◽  
pp. 481-488 ◽  
Author(s):  
Chairat Nawong ◽  
Kamontam Umsakul ◽  
Natthawan Sermwittayawong
Keyword(s):  
Mixed Culture ◽  
Pure Culture ◽  
Soil Samples

Allelopathic and autotoxic interactions in selected populations of Loliumperenne grown in monoculture and mixed culture

2002 ◽  
Vol 29 (12) ◽  
pp. 1465 ◽  
Author(s):  
Edwin Kraus ◽  
Margje Voeten ◽  
Hans Lambers
Keyword(s):  
Mixed Culture ◽  
Biomass Allocation ◽  
Dark Respiration ◽  
Total Yield ◽  
The Other ◽  
Leaf Dark Respiration ◽  
Short And Long Term ◽  
Allelopathic Effects ◽  
Two Populations

Autotoxicity and allelopathy affect the respiration and yield of GL66 and GL72, two populations of perennial ryegrass (Lolium perenne L. cv. S23) that were originally selected for contrasting rates of mature-leaf dark respiration under conditions where allelopathic effects could not occur and autotoxic effects were minimal. The aim of this study was to further investigate growth and biomass allocation of these two populations in relation to their autotoxic and allelopathic properties. To this end, plants were subjected to two conditions (monoculture and mixed culture) and two treatments (growth in 'renewed' and 'replenished' nutrient solution, allowing for short- and long-term accumulation of allelochemicals, respectively). The fast-respiring population, GL66, showed a reduced total yield due to allelopathic effects only when long-term accumulation of allelochemicals was allowed (mixed culture, replenished). However, short-term accumulation (mixed culture, renewed) of allelochemicals was sufficient to affect allocation of biomass to leaf sheaths. The slow-respiring population, GL72, suffered from autotoxicity only when long-term accumulation was allowed (monoculture, replenished), and from allelopathy under both short- and long-term accumulation (mixed culture, either renewed or replenished). The predominant allelopathic and autotoxic effect was on dry matter percentage and dry weight of leaf sheaths. We conclude that the roots of both populations release one or more chemical compounds that primarily affect biomass allocation to leaf sheaths, both of the same and of the other population. Sensitivity to the putative inhibitor(s) released by the other population was greater than sensitivity to the inhibitor(s) released by a population's own roots.

scholarly journals Seed Pretreatment for Increased Hydrogen Production Using Mixed-Culture Systems with Advantages over Pure-Culture Systems

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 530 ◽  
Author(s):  
Vinayak Laxman Pachapur ◽  
Prianka Kutty ◽  
Preetika Pachapur ◽  
Satinder Kaur Brar ◽  
Yann Le Bihan ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Mixed Culture ◽  
Pure Culture ◽  
Wide Spectrum ◽  
Low Cost ◽  
Production Costs ◽  
Microbial Consortia ◽  
Culture Systems ◽  
Seed Pretreatment ◽  
Media Supplements

Hydrogen is an important source of energy and is considered as the future energy carrier post-petroleum era. Nowadays hydrogen production through various methods is being explored and developed to minimize the production costs. Biological hydrogen production has remained an attractive option, highly economical despite low yields. The mixed-culture systems use undefined microbial consortia unlike pure-cultures that use defined microbial species for hydrogen production. This review summarizes mixed-culture system pretreatments such as heat, chemical (acid, alkali), microwave, ultrasound, aeration, and electric current, amongst others, and their combinations to improve the hydrogen yields. The literature representation of pretreatments in mixed-culture systems is as follows: 45–50% heat-treatment, 15–20% chemical, 5–10% microwave, 10–15% combined and 10–15% other treatment. In comparison to pure-culture mixed-culture offers several advantages, such as technical feasibility, minimum inoculum steps, minimum media supplements, ease of operation, and the fact it works on a wide spectrum of low-cost easily available organic wastes for valorization in hydrogen production. In comparison to pure-culture, mixed-culture can eliminate media sterilization (4 h), incubation step (18–36 h), media supplements cost ($4–6 for bioconversion of 1 kg crude glycerol (CG)) and around 10–15 Millijoule (MJ) of energy can be decreased for the single run.

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