Centrifuge separation effect on bacterial indicator reduction in dairy manure

Zong, Liu; Carroll, Zachary S.; Long, Sharon C.; Roa-Espinosa, Aicardo; Runge, Troy

doi:10.1016/j.jenvman.2017.01.022

Cited by 27 publications

(17 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These observations agreed with Liu et al (2017) who reported negligible changes in E. coli counts in RMS sampled after centrifugation compared with un-separated dairy manure. These authors also stipulated that high centrifugation speed and long retention time should be considered to improve bacterial reduction in RMS.…”

Section: Bacteriological Compositionsupporting

confidence: 92%

Production of recycled manure solids for bedding in Canadian dairy farms: I. Solid–liquid separation

Fournel

Godbout

Ruel

et al. 2019

Journal of Dairy Science

View full text Add to dashboard Cite

Canadian dairy producers have an increasing interest in recycled manure solids (RMS) as bedding material because of reduced availability of traditional bedding resources. Information regarding methods to obtain RMS and composition of RMS is very limited. Hence, a 2-part investigation was developed to compare the performances of 3 mechanical solid-liquid manure separators (part I) and 4 composting methods (part II; companion paper in this issue) for the production of high quality RMS. In this first study, a roller press, a screw press, and a decanter centrifuge were tested for the separation of slurry manure from a commercial dairy farm. During the experiment, the quantity of slurry manure processed and the volume and mass of the liquid and solid fractions were measured. The energy consumption of each separator was recorded, and samples of the slurry, liquid, and solid effluents were collected for analysis. The type of separator did not significantly influence the chemical and bacteriological composition of RMS produced. The choice of a separator for Canadian dairy producers should thus be based on the equipment cost and its capacity, targeted solids dry matter (DM) content and structure, and fertilizing quality of the separated liquid. The decanter centrifuge produced the solid phase with the highest DM and best separation efficiencies for DM, N, and P. However, its low production capacity (1.5 m 3 /h vs. 9.1-20.3 m 3 /h) combined with its high acquisition cost (Can$145,000 vs. Can$75,000) and energy consumption (4.99 kWh/ m 3 vs. 0.10-0.35 kWh/m 3 ) reduce its technical and profitability values. Besides, the centrifuge produced fine structured RMS and a low-quality liquid fraction, not suitable as dairy cow bedding and fertilizer, respectively. Both presses reached acceptable production capacity at a minimal operation cost. However, the poor performance in terms of DM (25%) of the model of screw press used in this study produced RMS unsuitable for immediate use without further processing. The model of roller press used in this study had the advantages of almost reaching the recommended DM content in RMS (>34%), being flexible in terms of inputs, and producing fluffy RMS. Nevertheless, its compression process seemed to allow greater passage of solids into the liquid fraction compared with the screw press. Part II of this work explores different composting methods to reduce the health risks associated with screw-pressed RMS before their use as bedding.

show abstract

Section: Bacteriological Compositionsupporting

confidence: 92%

Production of recycled manure solids for bedding in Canadian dairy farms: I. Solid–liquid separation

Fournel

Godbout

Ruel

et al. 2019

Journal of Dairy Science

View full text Add to dashboard Cite

show abstract

“…This short and mild centrifugation step reduces the bacteria in the supernatant dramatically without destroying them. Centrifugation at 10,000× g was shown to reduce bacteria from the solution up to 99% [ 37 ], but forces greater than 5000× g have been shown to cause bacterial damage [ 38 ], which we wanted to avoid. Furthermore, smaller soluble molecules will not sediment during centrifugation because this needs substantially higher centrifugation speed and time.…”

Section: Methodsmentioning

confidence: 99%

The Bacterium Pantoea ananatis Modifies Behavioral Responses to Sugar Solutions in Honeybees

Scheiner

Strauß

Thamm

et al. 2020

Insects

View full text Add to dashboard Cite

1. Honeybees, which are among the most important pollinators globally, do not only collect pollen and nectar during foraging but may also disperse diverse microbes. Some of these can be deleterious to agricultural crops and forest trees, such as the bacterium Pantoea ananatis, an emerging pathogen in some systems. P. ananatis infections can lead to leaf blotches, die-back, bulb rot, and fruit rot. 2. We isolated P. ananatis bacteria from flowers with the aim of determining whether honeybees can sense these bacteria and if the bacteria affect behavioral responses of the bees to sugar solutions. 3. Honeybees decreased their responsiveness to different sugar solutions when these contained high concentrations of P. ananatis but were not deterred by solutions from which bacteria had been removed. This suggests that their reduced responsiveness was due to the taste of bacteria and not to the depletion of sugar in the solution or bacteria metabolites. Intriguingly, the bees appeared not to taste ecologically relevant low concentrations of bacteria. 4. Synthesis and applications. Our data suggest that honeybees may introduce P. ananatis bacteria into nectar in field-realistic densities during foraging trips and may thus affect nectar quality and plant fitness.

show abstract

“…Centrifugation in essence involves compacting bacteria into a pellet, causing collisions against each other that result in shear forces on the bacterial cell surface, which may easily lead to cell surface damage (Peterson et al, 2012). According to Liu et al (2017), total coliform and E. coli densities in the liquid phase of processed manure were all reduced after centrifugation. Ratnam and March (1986) established that after centrifugation, most bacteria were concentrated in the sediment and that only very few remain in the supernatant in an uneven distribution throughout the fluid column.…”

Section: Bacterial Contamination Of Yolk-citrate Extender Across Storage Periodsmentioning

confidence: 99%

Bacteriological studies on egg yolk forms and different formulations of yolk-citrate semen extender

Ugbamaja¹,

Salisu²,

Sadiq³

et al. 2021

J. Vet. Med. Anim. Health

View full text Add to dashboard Cite

Using a tabular design, the bacteriological profile of egg yolk forms and different formulations of yolkcitrate semen extenders across different storage periods was examined. Twenty-one eggs less than 24 h old were randomly selected from 3 crates of eggs. The yolks were harvested and divided into two equal parts. One part was centrifuged for 1 h at 3500 revolutions per minute (rpm) to get clarified yolk. The remaining part was left whole. Each part was divided into three aliquots, one of which was cultured immediately (pre-storage) on MacConkey, Chocolate, Deoxycholate Citrate and Sabouraud Dextrose Agars and the other two stored each for 24 and 48 h before culture on the same media. The cultures were incubated for 24 h at 37°C. Left over egg yolks were pooled according to forms and kept frozen (-20°C) before being used to formulate extenders. Four different extenders were prepared using the clarified and whole yolks with or without antibiotics. The extenders were treated as previously described for egg yolk. Plates with apparent colonies were subjected to biochemical tests to identify the isolates and antibiotic susceptibility testing after the colonies were counted. Clarified yolk was less contaminated compared to whole egg yolk. Staphylococcus aureus was isolated from whole egg yolk and it was sensitive to Streptomycin, Amoxicillin, Neomycin, Penicillin and Cefoxitin but resistant to Gentamicin. Extenders with antibiotics were less contaminated than extenders without antibiotics. Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli and Salmonella species were isolated from semen extenders without antibiotics. All isolates were sensitive to Gentamicin. In conclusion, clarified yolk and extenders containing clarified yolk with antibiotics had no contamination. Hence, clarified yolk should be used in the preparation of extenders instead of whole yolks. Also, Gentamicin should be included in extender formulations to reduce bacterial contamination.

show abstract

Centrifuge separation effect on bacterial indicator reduction in dairy manure

Cited by 27 publications

References 20 publications

Production of recycled manure solids for bedding in Canadian dairy farms: I. Solid–liquid separation

Production of recycled manure solids for bedding in Canadian dairy farms: I. Solid–liquid separation

The Bacterium Pantoea ananatis Modifies Behavioral Responses to Sugar Solutions in Honeybees

Bacteriological studies on egg yolk forms and different formulations of yolk-citrate semen extender

Contact Info

Product

Resources

About