scholarly journals The effect of calcium on biofilm formation in dairy wastewater

2018 ◽  
Vol 13 (2) ◽  
pp. 400-409 ◽  
Author(s):  
M. J. L. Dixon ◽  
S. H. Flint ◽  
J. S. Palmer ◽  
R. Love ◽  
C. Chabas ◽  
...  
Keyword(s):  
Growth Rates ◽  
Biofilm Formation ◽  
Irrigation System ◽  
Dairy Wastewater ◽  
Growth And Yield ◽  
Anaerobic Conditions ◽  
Biofilm Growth ◽  
Irrigation Pipes ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Abstract Biofilm formation in dairy wastewater system irrigation pipes can reduce treatment capacity, increasing maintenance and cleaning costs. Understanding the effect of different components in the wastewater on growth and yield of bacteria present could help prevent excessive build-up of biofilms. This study investigated, in aerobic and anaerobic conditions, the effect of calcium, sodium and magnesium concentrations on growth rates, yields and saturation constants of four known biofilm forming bacteria associated with the blockage of an irrigation system. The ions tested (Ca2+, Mg2+, Na+) varied growth rates with biofilm growth in the presence of calcium being significantly slower (P < 0.05) than planktonic growth in sodium. Along with the slower growth, the addition of Ca2+ (up to 0.1 M) increased biofilm formation while addition over 0.5 M prevented biofilm formation. Knowing the nutritional requirements of the bacteria and the effects of the ions will be useful in predicting the growth, development and strategies in controlling biofilm formation in dairy wastewater.

Oxygen concentration affects frequency and range of transconjugants for the incompatibility (Inc) P-1 and P-7 plasmids pBP136 and pCAR1

2020 ◽  
Vol 85 (4) ◽  
pp. 1005-1015
Author(s):  
Kentaro Ochi ◽  
Maho Tokuda ◽  
Kosuke Yanagiya ◽  
Chiho Suzuki-Minakuchi ◽  
Hideaki Nojiri ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Anaerobic Condition ◽  
Environmental Samples ◽  
Aerobic Condition ◽  
Recipient Strain ◽  
Donor Strain ◽  
Anaerobic Conditions ◽  
Filter Mating ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

ABSTRACT The frequency of transconjugants were compared for the incompatibility (Inc) P-1 and P-7 plasmids pBP136 and pCAR1 under aerobic and anaerobic conditions. Filter mating assays were performed with one donor strain and one recipient strain using different donors of Pseudomonas and recipient strains, including Pseudomonas, Pantoea, and Buttiauxella. Under anaerobic condition, frequencies of transconjugants for both plasmids were 101-103-fold lower than those under aerobic condition regardless of whether aerobically or anaerobically grown donors and recipients were used. To compare the transconjugant ranges under aerobic and anaerobic conditions, conjugation was performed between the donor of pBP136 and recipient bacteria extracted from environmental samples. Several transconjugants were uniquely obtained from each aerobic or anaerobic condition. Our findings indicate that a plasmid can differently spread among bacteria depending on the oxygen concentrations of the environment.

PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: VII. FERMENTATION OF WHEAT BY AEROBACILLUS POLYMYXA UNDER AEROBIC AND ANAEROBIC CONDITIONS

1946 ◽  
Vol 24f (1) ◽  
pp. 1-11 ◽  
Author(s):  
G. A. Adams
Keyword(s):  
Carbon Dioxide ◽  
Anaerobic Fermentation ◽  
Anaerobic Conditions ◽  
Mechanical Agitation ◽  
Fermentation Time ◽  
Aerobic Conditions ◽  
Ethanol Formation ◽  
Time Required ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Aeration by mechanical agitation of 15% wheat mash fermented by Aerobacillus polymyxa inhibited the formation of 2,3-butanediol and particularly of ethanol. Aeration of similar mashes by passage of finely dispersed air or oxygen at the rate of 333 ml. per minute per litre of mash increased the rate of formation and yield of 2,3-butanediol but inhibited ethanol formation. However, the over-all time required for the completion of fermentation was not shortened from the usual 72 to 96 hr. required for unaerated mashes. There was no evidence of a shift from fermentative to oxidative dissimilation. Under aerobic conditions, the final butanediol–ethanol ratio was approximately 3:1. Anaerobic conditions, as produced by the passage of nitrogen or hydrogen through the mash, increased the rate of formation of both butanediol and ethanol and shortened the fermentation time to about 48 hr. Under these conditions, the butanediol–ethanol ratio was reduced to about 1.3:1.0. Carbon dioxide gave a butanediol–ethanol ratio resembling that of anaerobic fermentation but did not reduce fermentation time.

scholarly journals Optimizing characteristics in mineral insulating oil used in high power transformers

2019 ◽  
pp. 222-228
Author(s):  
Irina Alina Chera Anghel ◽  
Loredana Popescu
Keyword(s):  
Mineral Oil ◽  
The Other ◽  
Power Transformers ◽  
Anaerobic Conditions ◽  
Mineral Oils ◽  
Insulating Liquid ◽  
Different Characteristics ◽  
Aerobic And Anaerobic ◽  
Good Heat ◽  
Aerobic And Anaerobic Conditions

The most commonly used insulating liquid in transformers is mineral oil. Special synthetic applications such as silicone, ester, perchloroethene, etc. are used today in special applications, with different characteristics, very low or nonexistent toxicity to mineral oils used in transformers. On the other hand, they have a much better biodegradability than mineral oils in both aerobic and anaerobic conditions. But they cannot directly replace the mineral oil in operation or in repaired units. They have dielectric properties and good heat transfer but have limited their use to special transformers due to the relatively high cost and availability.

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