scholarly journals Shifts in microbial populations in Rusitec fermenters as affected by the type of diet and impact of the method for estimating microbial growth (15N v. microbial DNA)

animal ◽  
2017 ◽  
Vol 11 (11) ◽  
pp. 1939-1948 ◽  
Author(s):  
I. Mateos ◽  
M.J. Ranilla ◽  
C. Saro ◽  
M.D. Carro
Keyword(s):  
Microbial Growth ◽  
Microbial Populations ◽  
Microbial Dna

scholarly journals Enhancement in physicochemical parameters and microbial populations of mushrooms as influenced by nano-coating treatments

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rokayya Sami ◽  
Abeer Elhakem ◽  
Amina Almushhin ◽  
Mona Alharbi ◽  
Manal Almatrafi ◽  
...  
Keyword(s):  
Physicochemical Parameters ◽  
Microbial Growth ◽  
Research Work ◽  
Microbial Populations ◽  
Coating Film ◽  
Epidermal Structure ◽  
Nano Coating ◽  
Soluble Solid ◽  
Button Mushrooms ◽  
White Button Mushrooms

AbstractWhite button mushrooms are greatly high perishable and can deteriorate within a few days after harvesting due to physicomechanical damage, respiration, microbial growth of the delicate epidermal structure. For that reason, the present research work was applied to evaluate the effect of chitosan combination with nano-coating treatments on physicochemical parameters and microbial populations on button mushrooms at chilling storage. Nano coating with the addition of nisin 1% (CHSSN/M) established the minimum value for weight loss 12.18%, maintained firmness 11.55 N, and color index profile. Moreover, O2% rate of (CHSSN/M) mushrooms was the lowest at 1.78%; while the highest rate was reported for CO2 24.88% compared to the untreated samples (Control/M) on day 12. Both pH and total soluble solid concentrations increased during storage. Results reported that the (CHSS/M) mushroom significantly (P < 0.05) reduced polyphenol oxidase activity (24.31 U mg−1 Protein) compared with (Control/M) mushrooms that increased faster than the treated samples. (CHSSN/M) treatment was the most efficient in the reduction of yeast and mold, aerobic plate microorganisms (5.27–5.10 log CFU/g), respectively. The results established that nano-coating film might delay the aging degree and accompany by marked prolongation of postharvest mushroom freshness.

scholarly journals Effects of Replacing Extruded Maize by Dried Citrus Pulp in a Mixed Diet on Ruminal Fermentation, Methane Production, and Microbial Populations in Rusitec Fermenters

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1316
Author(s):  
Jairo García-Rodríguez ◽  
Cristina Saro ◽  
Iván Mateos ◽  
Jesús S. González ◽  
María Dolores Carro ◽  
...  
Keyword(s):  
Methane Production ◽  
Microbial Growth ◽  
Microbial Populations ◽  
Mixed Diet ◽  
Ruminal Fermentation ◽  
Citrus Industry ◽  
Ph Values ◽  
Citrus Pulp ◽  
Liquid Phases ◽  
Fermentation Parameters

Citrus pulp is a highly abundant by-product of the citrus industry. The aim of this study was to assess the effects of replacing extruded maize (EM; 20% of total diet) by dried citrus pulp (DCP; 20%) in a mixed diet on rumen fermentation and microbial populations in Rusitec fermenters. The two diets contained 50% alfalfa hay and 50% concentrate, and the same protein level. Four Rusitec fermenters were used in a cross-over design with two 13-d incubation runs. After 7-d of diet adaptation, diet disappearance, fermentation parameters, microbial growth, and microbial populations were assessed. Fermenters receiving the DCP showed greater pH values and fiber disappearance (p < 0.001) and lower methane production (p = 0.03) than those fed EM. Replacing EM by DCP caused an increase in the proportions of propionate and butyrate (p < 0.001) and a decrease in acetate (p = 0.04). Microbial growth, bacterial diversity, and the quantity of bacteria and protozoa DNA were not affected by the diet, but the relative abundances of fungi and archaea were greater (p < 0.03) in solid and liquid phases of DCP fermenters, respectively. Results indicate that DCP can substitute EM, promoting a more efficient ruminal fermentation.

scholarly journals Succession of microbial populations and nitrogen-fixation associated with the biodegradation of sediment-oil-agglomerates buried in a Florida sandy beach

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Boryoung Shin ◽  
Ioana Bociu ◽  
Max Kolton ◽  
Markus Huettel ◽  
Joel E. Kostka
Keyword(s):  
Nitrogen Fixation ◽  
Petroleum Hydrocarbons ◽  
Microbial Growth ◽  
Sandy Beach ◽  
Sandy Beaches ◽  
Beach Sand ◽  
Microbial Populations ◽  
In Situ Experiment ◽  
Potential Threat ◽  
Nitrogenase Genes

AbstractThe Deepwater Horizon (DWH) oil spill contaminated coastlines from Louisiana to Florida, burying oil up to 70 cm depth in sandy beaches, posing a potential threat to environmental and human health. The dry and nutrient-poor beach sand presents a taxing environment for microbial growth, raising the question how the biodegradation of the buried oil would proceed. Here we report the results of an in-situ experiment that (i) characterized the dominant microbial communities contained in sediment oil agglomerates (SOAs) of DWH oil buried in a North Florida sandy beach, (ii) elucidated the long-term succession of the microbial populations that developed in the SOAs, and (iii) revealed the coupling of SOA degradation to nitrogen fixation. Orders of magnitude higher bacterial abundances in SOAs compared to surrounding sands distinguished SOAs as hotspots of microbial growth. Blooms of bacterial taxa with a demonstrated potential for hydrocarbon degradation (Gammaproteobacteria, Alphaproteobacteria, Actinobacteria) developed in the SOAs, initiating a succession of microbial populations that mirrored the evolution of the petroleum hydrocarbons. Growth of nitrogen-fixing prokaryotes or diazotrophs (Rhizobiales and Frankiales), reflected in increased abundances of nitrogenase genes (nifH), catalyzed biodegradation of the nitrogen-poor petroleum hydrocarbons, emphasizing nitrogen fixation as a central mechanism facilitating the recovery of sandy beaches after oil contamination.

PREDOMINANT MICROORGANISMS ON RAW PLANT FOODS1,2

1970 ◽  
Vol 33 (11) ◽  
pp. 500-505 ◽  
Author(s):  
D. F. Splittstoesser
Keyword(s):  
Microbial Growth ◽  
Microbial Populations ◽  
Green Beans ◽  
Plant Foods ◽  
Microbial Counts ◽  
Equipment Contamination ◽  
Growth History

Considerable variation was observed in the microbial populations present on raw plant foods. Equipment contamination and microbial growth on the product following harvest often were responsible for high microbial counts. Because of these factors, vegetables protected by a pod or husk frequently were more heavily contaminated than those exposed to soil and air throughout their growth history. Similar types of microorganisms were isolated from raw and post-blanch samples of peas and green beans. The samples recontaminated after the blanch generally contained a higher proportion of catalase-negative cocci. Some of the properties of the more numerous groups are presented. Many of the isolates were sufficiently different from “type” cultures that they could not be readily placed into described species.

scholarly journals Growth tradeoffs produce complex microbial communities on a single limiting resource

2018 ◽  
Author(s):  
Michael Manhart ◽  
Eugene I. Shakhnovich
Keyword(s):  
Microbial Growth ◽  
Growth Traits ◽  
Fundamental Problem ◽  
Higher Order ◽  
Microbial Populations ◽  
Order Effects ◽  
Pairwise Interactions ◽  
Lag Times ◽  
The Relationship ◽  
Higher Order Effects

The relationship between the dynamics of a community and its constituent pairwise interactions is a fundamental problem in ecology. Higher-order ecological effects beyond pairwise interactions may be key to complex ecosystems, but mechanisms to produce these effects remain poorly understood. Here we show that higher-order effects can arise from variation in multiple microbial growth traits, such as lag times and growth rates, on a single limiting resource with no other interactions. These effects produce a range of ecological phenomena: an unlimited number of strains can exhibit multi stability and neutral coexistence, potentially with a single keystone strain; strains that coexist in pairs do not coexist all together; and the champion of all pairwise competitions may not dominate in a mixed community. Since variation in multiple growth traits is ubiquitous in microbial populations due to pleiotropy and non-genetic variation, our results indicate these higher-order effects may also be widespread, especially in laboratory ecology and evolution experiments.

scholarly journals A Comparison of Sanitation Systems for Fresh-cut Mango

2005 ◽  
Vol 15 (4) ◽  
pp. 837-842 ◽  
Author(s):  
Jan Narciso ◽  
Anne Plotto
Keyword(s):  
Microbial Growth ◽  
Mangifera Indica ◽  
Quality Parameters ◽  
Microbial Populations ◽  
Sodium Chlorite ◽  
Peroxyacetic Acid ◽  
Microbial Counts ◽  
Fresh Cut ◽  
Microbial Stability ◽  
Sanitation Systems

A comparison of sanitizers for fresh-cut mango (Mangifera indica cv. Keitt) was made. Mangos were obtained from a farm in Homestead, Fla., and stored at 15 °C until processed. Before cutting, fruit were dipped in solutions of either sodium hypochlorite (NaOCl) (200 ppm) or peroxyacetic acid (100 ppm). The cut pieces were dipped in acidified sodium chlorite (NaClO2) (200 ppm, pH 2.6) or dilute peroxyacetic acid (50 ppm) for 30 seconds. Resulting cut slices were placed in polystyrene clamshell food containers and stored at 5 °C for 21 days. Samples in the clamshells were tested for changes in microbial stability and for quality parameters every 7 days. Results showed that even though the fruit slices were sanitized after cutting, cut fruit microbial populations were related to the method of whole fruit sanitation. After 15-21 days in storage at 5 °C, cut slices from whole fruit sanitized with peroxyacetic acid that were subsequently treated with dilute peroxyacetic acid or acidified NaClO2 had less contamination [<1 colony-forming unit (cfu) per gram] than samples cut from whole fruit sanitized with NaOCl (<1000 to 3700 cfu/g). These data demonstrate that the method of whole fruit sanitation plays a role in determining the cleanliness of the cut fruit. These sanitizer systems (peroxyacetic acid on whole fruit followed by peroxyacetic acid or acidified NaClO2 on cut slices) effectively reduced microbial growth and kept microbial counts low on cut fruit surfaces for 21 days when compared to cut fruit slices from NaOCl-treated whole fruit.

The Effect of Bioremediation on Microbial Populations in an Oil-Contaminated Coastal Wetland

1999 ◽  
Vol 1999 (1) ◽  
pp. 477-483 ◽  
Author(s):  
Richard T. Townsend ◽  
James S. Bonner ◽  
Robin l. Autenrieth
Keyword(s):  
Petroleum Hydrocarbon ◽  
Microbial Growth ◽  
Coastal Wetland ◽  
Aliphatic Hydrocarbon ◽  
Diammonium Phosphate ◽  
Microbial Populations ◽  
Hydrocarbon Biodegradation ◽  
Sediment Samples ◽  
Polycyclic Aromatic ◽  
Phosphate Treatment

ABSTRACT A series of controlled crude oil applications was carried out in a Texas coastal wetland to determine the effectiveness of bioremediation in these sensitive areas. The first application, conducted in 1996, was performed to assess the use of diammonium phosphate and diammonium phosphate plus a potential electron acceptor (nitrate) to stimulate microbial growth and subsequent hydrocarbon degradation. The second application, conducted in 1997, was performed to determine the potential of two commercial bioaugmentation products to enhance hydrocarbon biodegradation. Diammonium phosphate was also re-evaluated during this phase as a bio stimulation treatment. For both applications, sediment samples from all oiled test plots showed exponential increases in the numbers of aliphatic hydrocarbon and polycyclic aromatic hydrocarbon (PAH)-degrading microorganisms. Average numbers of aliphatic-degrading and PAH-degrading microorganisms were slightly higher (though not significantly higher) than populations on oiled control plots on most sample days. The bioaugmentation products and diammonium phosphate treatment examined during the second application did not significantly increase the numbers of hydrocarbon-degrading microorganisms (aliphatic-degraders or PAH-degraders). Overall, the microbial populations from both phases of research illustrated a well-documented response to a petroleum hydrocarbon input. Although the bioremediation treatments did not appear to significantly increase these populations, this data will be evaluated with nutrient and petroleum hydrocarbon data to determine the effectiveness of bioremediation in wetland areas.

Measurement and quantification of sessile and planktonic microbial populations during the anaerobic digestion of cellulose

2008 ◽  
Vol 57 (4) ◽  
pp. 465-469 ◽  
Author(s):  
P. D. Jensen ◽  
M. T. Hardin ◽  
W. P. Clarke
Keyword(s):  
Regression Analysis ◽  
Microbial Growth ◽  
Cellulose Degradation ◽  
Ammonia Nitrogen ◽  
Microbial Populations ◽  
Crystalline Cellulose ◽  
Total Biomass ◽  
Cell Counts ◽  
Direct Cell ◽  
Protein Assays

Crystalline cellulose was anaerobically degraded using a leachate inoculum derived from simulated municipal solid waste. Bicinchoninic Acid (BCA) protein assays were used to measure the distribution of biomass during cellulose degradation, including the planktonic and sessile biomass fractions. A comparison of sessile and planktonic microbial growth indicated that the microbial growth was dominated by the planktonic fraction with the biofilms accounting for approximately 25% of the population. Additional biomass measurements were conducted to test the reliability of the BCA protein assays. Total microbial growth was inferred from the accumulation and depletion of ammonia nitrogen measured using flow injection analysis. The planktonic biomass was estimated from direct cell counts using light microscopy and the sessile biomass was estimated by analysing the nitrogen content of the separated and washed cellulose pellet. Regression analysis showed good correlations between the measurement pairs representing the total biomass (R2=0.90), planktonic biomass (R2=0.97) and sessile biomass (R2=0.85), supporting the use of protein assays as an indicator of microbial growth in mixed culture environments.

scholarly journals AMiGA: Software for Automated Analysis of Microbial Growth Assays

mSystems ◽  
2021 ◽  
Author(s):  
Firas S. Midani ◽  
James Collins ◽  
Robert A. Britton
Keyword(s):  
Microbial Growth ◽  
Growth Dynamics ◽  
Automated Analysis ◽  
Current Understanding ◽  
Microbial Populations ◽  
Simple Method ◽  
Microbial Physiology ◽  
Over Time

Our current understanding of microbial physiology relies on the simple method of measuring microbial populations’ sizes over time and under different conditions. Many advances have increased the throughput of those assays and enabled the study of nonlab-adapted microbes under diverse conditions that widely affect their growth dynamics.

Effect of Chemical Treatments on Microbiological, Sensory and Physical Qualities of Individually Shrink-Wrapped Produce

1987 ◽  
Vol 50 (8) ◽  
pp. 673-680 ◽  
Author(s):  
D. A. GOLDEN ◽  
E. K. HEATON ◽  
L. R. BEUCHAT
Keyword(s):  
Storage Time ◽  
Microbial Growth ◽  
Fruits And Vegetables ◽  
Quaternary Ammonium Compound ◽  
The Other ◽  
Microbial Populations ◽  
Ammonium Compound ◽  
Chemical Treatments ◽  
Brown Discoloration ◽  
Bell Peppers

Effects of four chemical treatments on microbiological, sensory and physical qualities of individually shrink-wrapped bell peppers, tomatoes, peaches and cantaloupes stored at 0 to 21°C were determined. With the exception of produce treated with guazatine, higher populations of microorganisms were detected on shrink-wrapped produce than on unwrapped produce as storage time increased. Treatment of wrapped produce with guazatine generally controlled microbial populations at about the same levels or at lower levels than those detected on unwrapped produce treated with imazalil, chlorine and a quaternary ammonium compound. Little inhibition of microbial growth compared to untreated produce was observed on fruits and vegetables treated with the latter three chemicals. None of the chemicals had deleterious effects on sensory or physical qualities of produce, with the exception of imazalil which caused severe brown discoloration on wrapped and unwrapped peaches. Shrink-wrapping retarded loss of firmness of chemically treated and untreated bell peppers, but had little effect on changes in firmness of the other produce during storage.

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