Metabolic history and metabolic fitness as drivers of anabolic heterogeneity in isogenic microbial populations

A study was carried out in six beet sugar factories in France during the 2012/13 sugar campaign. The objective was to assess the optimal dosage of formaldehyde solutions at specific process stages and in different existing factory set-ups in order to obtain the desired effect on microbial populations, without interference with the quality of the products. In addition harmlessness regarding consumer health was to be demonstrated. A series of experiments was conducted resulting in new data allowing refreshment of common knowledge and references existing regarding the use of formaldehyde solutions in the sugar industry. The effectiveness and convenience for controlling microbiological activity in beet sugar manufacture was assessed. Formaldehyde reduces sugar losses and protects in-process products without harming their further use, such as for ethanol production.

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Isolation of Epigallocatechin Gallate from Green Tea and its Effects on Probiotics and Pathogenic Bacteria

Current Topics in Nutraceutical Research ◽

10.37290/ctnr2641-452x.17:69-77 ◽

2017 ◽

Vol 17 (1) ◽

pp. 69-77

Author(s):

Tu Lijun ◽

Sun Hanju ◽

He Shudong ◽

Zhu Yongsheng ◽

Yu Ming ◽

...

Keyword(s):

Mass Spectrometry ◽

Escherichia Coli ◽

Green Tea ◽

Lactobacillus Acidophilus ◽

Pathogenic Bacteria ◽

Epigallocatechin Gallate ◽

Microbial Populations ◽

Medium Ph ◽

Bioactive Substance ◽

Tea Extract

The aim of this study was to investigate epigallocatechin gallate (EGCG) prebiotics activities systematically which was reported as a bioactive substance. Therefore, EGCG was separated by water extraction, resin purification and prep-HPLC. Then the production of EGCG was confirmed by HPLC and mass spectrometry (MS) analysis and its purify was 97.23%. EGCG extractive and green tea extract (GTE) were further incubated with Bifidobacterium infantis, B. adolescentis, B. bifidum and Lactobacillus acidophilus to study its effect on microbial populations and medium pH. Finally, Escherichia coli, Salmonella, Staphylococcus aureus and Candida albicans were employed as pathogenic bacteria to explore the antimicrobial activity of EGCG and GTE. The results demonstrated that EGCG extractive could be beneficial for the proliferation of Bifidobacterium and L. acidophilus and also inhibit some pathogenic bacteria. In conclusion, both EGCG extractive and GTE had prebiotics activities and the effects of EGCG extractive were superior to those of GTE.

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Using microbial fatty acids to quantify, characterize and compare biofilm and suspended microbial populations in wastewater treatment systems

Water Science & Technology ◽

10.2166/wst.1998.0644 ◽

1998 ◽

Vol 38 (4-5) ◽

pp. 273-280 ◽

Cited By ~ 3

Author(s):

A. G. Werker ◽

E. R. Hall

Keyword(s):

Fatty Acid ◽

Methyl Esters ◽

Ph Control ◽

Microbial Populations ◽

Total Organic Carbon Removal ◽

Operating Limits ◽

Suspended Biomass ◽

Kraft Mill Effluent ◽

Microbial Fatty Acid ◽

Influence Of Ph

Spectra of microbial fatty acid methyl esters were used to assess the influence of pH on the biofilm and suspended biomass populations within bench scale moving bed bioreactors treating bleached kraft mill effluent. The fatty acid spectral data were reduced by logcontrast canonical component analysis. The first canonical component differentiated biofilm from suspended populations and the second two appeared to indicate an influence of pH on microbial ecology. Thus, the biofilm and suspended microbial communities were distinct, as were the populations acclimated at pH 6 and pH 8. Experimental data for total organic carbon removal suggested that the more recalcitrant fraction of the influent was consumed by the slower growing, high SRT biofilm fraction of the biomass. Since the biofilm ecology was sensitive to pH within typical pH operating limits of full-scale systems, tighter pH control might improve treatment reliability in the event of process transients.

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Bio-P and non-bio-P bacteria identification by a novel microbial approach

Water Science & Technology ◽

10.2166/wst.1999.0249 ◽

1999 ◽

Vol 39 (6) ◽

pp. 13-20 ◽

Cited By ~ 6

Author(s):

Philip L. Bond ◽

Jürg Keller ◽

Linda L. Blackall

Keyword(s):

In Situ Hybridisation ◽

Microbial Populations ◽

Biological Phosphorus Removal ◽

Gram Positive Bacteria ◽

P Content ◽

Identification Of Bacteria ◽

Widespread Belief ◽

Biological Phosphorus ◽

P Removal

Culturing bacteria from activated sludge with enhanced biological phosphorus removal (EBPR) has strongly implicated Acinetobacter with the process. However, using fluorescent in-situ hybridisation (FISH) probing to analyse microbial populations, we have shown evidence opposing this widespread belief. We describe the phosphorus (P) removing performance and microbial population analyses of sludges obtained in a laboratory scale EBPR reactor. Two sludges with extremely high P removing capabilities were examined, the P content of these sludges was 8.6% (P sludge) and 12.3% (S sludge) of the MLSS. Identification of bacteria using FISH probing indicated both sludges were dominated by microbes from the beta proteobacteria and high mol% G+C Gram positive bacteria. Acinetobacter could make up only a small proportion of the cells in these sludges. Sludge with extremely poor P removal (P content of 1.5%, referred to as T sludge) was then generated by reducing the P in the influent. Bacteria resembling the G-bacteria became abundant in this sludge and these were identified using FISH probing. The anaerobic transformations of the T and P sludges correlated well with that of the non-EBPR and EBPR biological models respectively, indicating that bacteria in the T sludge have the potential to inhibit P removal in EBPR systems.

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UV Irradiation of Shell Eggs: Effect on Populations of Aerobes, Molds, and Inoculated Salmonella typhimurium

Journal of Food Protection ◽

10.4315/0362-028x-60.6.639 ◽

1997 ◽

Vol 60 (6) ◽

pp. 639-643 ◽

Cited By ~ 69

Author(s):

FUENG-LIN KUO ◽

JOHN B. CAREY ◽

STEVEN C. RICKE

Keyword(s):

Salmonella Typhimurium ◽

Uv Radiation ◽

Uv Light ◽

The Other ◽

Uv Exposure ◽

Microbial Populations ◽

Aerobic Bacteria ◽

Fluorescent Light ◽

Uv Treatment ◽

Shell Eggs

The effects were investigated of 254-nm UV radiation on populations of Salmonella typhimurium, aerobes, and molds on the shells of eggs. In the first experiment, the CFU of attached S. typhimurium cells on unwashed clean shell eggs were determined after 0, 1, 3, 5, and 7 min of UV treatment (620 μW/cm2) on both ends of the egg. All UV treatments significantly reduced S. typhimurium CFU (P < .01). UVtreatment (620 μW/cm2) in 1-min alternating light and dark cycles for 5 min (three light and two dark) was compared to 0, 3, and 5 min of UV treatment. No significant differences in microbial populations were observed among light and dark cycles and the other UV treatments. In a subsequent experiment, the same UV treatments were utilized to evaluate photoreactivation. After UV exposure, eggs were exposed to 1 h of fluorescent light or I h of darkness or cultured immediately. S. typhimurium CFU were significantly (P < .01) reduced by the UV treatments. However, no significant differences between microbial populations exposed to UV treatment and UV radiation plus photoreactivation were detected. For studies of aerobic bacteria and molds, different UV treatment times (0, 15, and 30 min) at the intensity of 620 μW/cm2 and different intensities (620, 1350, and 1720 μW/cm2) for 15 min were evaluated. Mold CFU per egg were either 0 or 1 for all UV treatments and a 99% reduction of CFU of aerobic bacteria per egg were observed for all UV treatments. It appears from these studies that UV light can significantly reduce populations of S. typhimurium, aerobes, and molds on shell eggs.

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