Mineralogical Controls on Microbial Reduction of Fe(III) (Hydr)oxides

An effective and eco-friendly technology is needed to prevent postharvest loss of onion bulbs during cold storage. This study investigated the effect of gaseous ozone on the decay and quality of onion bulbs during storage at 2 °C and 70% relative humidity for two months. Gaseous ozone was adjusted to a concentration of 1.27 ± 0.024 ppm in the storage room by generating a high voltage discharge in air. After two months of storage, gaseous ozone significantly reduced the counts of aerobic bacteria (e.g., Rahnella aquatilis) and fungi (e.g., yeast and mold) in the onion bulbs by 4 log (CFU g−1) and 0.92 log (CFU g−1) compared with those of an untreated control, respectively. The microbial reduction by gaseous ozone resulted in a lower rotten rate of the onion bulbs, which was less than 20.0% compared with that of the untreated control. Moreover, the ozone exposure extended the storage life of the onion bulbs by delaying its color change and softening during storage. Our results suggest that gaseous ozone can control the decay of onion bulbs safely during storage.

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Impact of sanitizer solutions on microbial reduction and quality of fresh-cut pennywort (Centella asiatica) leaves

Journal of Food Science and Technology ◽

10.1007/s13197-021-05131-3 ◽

2021 ◽

Author(s):

Siti Zaharah Rosli ◽

Mohd Adzahan Noranizan ◽

Son Radu ◽

Roselina Karim ◽

Noraniza Mohd Adzahan ◽

...

Keyword(s):

Centella Asiatica ◽

Microbial Reduction ◽

Fresh Cut

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Efficacy of Two Acidic Sanitizers for Microbial Reduction on Metal Cans and Low-Density Polyethylene Film Surfaces

Journal of Food Science ◽

10.1111/j.1750-3841.2007.00496.x ◽

2007 ◽

Vol 72 (8) ◽

pp. M335-M339 ◽

Cited By ~ 9

Author(s):

J. Lee ◽

M.J. Gupta ◽

J. Lopes ◽

M.A. Pascall

Keyword(s):

Microbial Reduction ◽

Polyethylene Film ◽

Low Density Polyethylene ◽

Low Density

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Insight to Microbial Fe(III) Reduction Mediated by Redox-Active Humic Acids with Varied Redox Potentials

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18136807 ◽

2021 ◽

Vol 18 (13) ◽

pp. 6807

Author(s):

Jingtao Duan ◽

Zhiyuan Xu ◽

Zhen Yang ◽

Jie Jiang

Keyword(s):

Molecular Weight ◽

Electron Transfer ◽

Humic Acids ◽

Weight Fraction ◽

Electrochemical Analysis ◽

Microbial Reduction ◽

Redox Potentials ◽

Groundwater Environment ◽

Redox Active ◽

Different Molecular Weight

Redox-active humic acids (HA) are ubiquitous in terrestrial and aquatic systems and are involved in numerous electron transfer reactions affecting biogeochemical processes and fates of pollutants in soil environments. Redox-active contaminants are trapped in soil micropores (<2 nm) that have limited access to microbes and HA. Therefore, the contaminants whose molecular structure and properties are not damaged accumulate in the soil micropores and become potential pollution sources. Electron transfer capacities (ETC) of HA reflecting redox activities of low molecular weight fraction (LMWF, <2.5) HA can be detected by an electrochemical method, which is related to redox potentials (Eh) in soil and aquatic environments. Nevertheless, electron accepting capacities (EAC) and electron donating capacities (EDC) of these LMWF HA at different Eh are still unknown. EDC and EAC of different molecular weight HA at different Eh were analyzed using electrochemical methods. EAC of LMWF at −0.59 V was 12 times higher than that at −0.49 V, while EAC increased to 2.6 times when the Eh decreased from −0.59 V to −0.69 V. Afterward, LMWF can act as a shuttle to stimulate microbial Fe(III) reduction processes in microbial reduction experiments. Additionally, EAC by electrochemical analysis at a range of −0.49–−0.59 V was comparable to total calculated ETC of different molecular weight fractions of HA by microbial reduction. Therefore, it is indicated that redox-active functional groups that can be reduced at Eh range of −0.49–−0.59 are available to microbial reduction. This finding contributes to a novel perspective in the protection and remediation of the groundwater environment in the biogeochemistry process.

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A PROPOSED METHODOLOGY FOR ASSESSING THE RELATIVE IMPACT OF ACID RAIN AND NITROGEN FERTILIZERS ON ACIDITY OF AGRICULTURAL SOILS IN CANADA

Canadian Journal of Soil Science ◽

10.4141/cjss89-061 ◽

1989 ◽

Vol 69 (3) ◽

pp. 611-627 ◽

Cited By ~ 1

Author(s):

D. R. COOTE ◽

S. SHAH SINGH ◽

C. WANG

Keyword(s):

Acid Rain ◽

Agricultural Soils ◽

Field Measurements ◽

Base Cation ◽

Microbial Reduction ◽

Base Saturation ◽

Nitrogen Fertilizers ◽

N Fertilizers ◽

Reduction Plant ◽

Sulfate Leaching

Acid rain and N fertilizers both contribute to soil acidity, but no method has been available to compare their relative impacts. A simple model (SOLACID) is presented to assess quantitatively the acidifying effects of precipitation and N fertilizers on agricultural soils. Acid rain has been treated as a dilute solution of NH4NO3, (NH4)2SO4 and associated acids. Soil and plant pathways are considered for [Formula: see text], [Formula: see text]and [Formula: see text] by way of leaching, gaseous losses from microbial reduction, plant uptake and removal, and organic immobilization and mineralization. Leaching of [Formula: see text] was the factor to which the model was most sensitive. A relationship between base saturation and base cation leaching is described. Field data reported from 21 treatments at six experimental sites were used to test the model, which provided reliable estimates of final pH (r2 = 0.92**) and of changes in base saturation (r2 = 0.86**). Compared with previously published methods, the model provided the best estimates of lime requirements as computed from field measurements (r2 = 0.87**). Key words: Ammonia, sulfate, leaching, nitrification

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