scholarly journals What’s new and notable in bacterial spore killing!

2021 ◽  
Vol 37 (8) ◽  
Author(s):  
Peter Setlow ◽  
Graham Christie
Keyword(s):  
Organic Matter ◽  
Food Quality ◽  
Elevated Temperatures ◽  
Biological Warfare ◽  
Food Spoilage ◽  
Dry Heat ◽  
Spore Killing ◽  
Minimal Damage ◽  
Presence Of People ◽  
High Hydrostatic Pressures

AbstractSpores of many species of the orders Bacillales and Clostridiales can be vectors for food spoilage, human diseases and intoxications, and biological warfare. Many agents are used for spore killing, including moist heat in an autoclave, dry heat at elevated temperatures, UV radiation at 254 and more recently 222 and 400 nm, ionizing radiation of various types, high hydrostatic pressures and a host of chemical decontaminants. An alternative strategy is to trigger spore germination, as germinated spores are much easier to kill than the highly resistant dormant spores—the so called “germinate to eradicate” strategy. Factors important to consider in choosing methods for spore killing include the: (1) cost; (2) killing efficacy and kinetics; (3) ability to decontaminate large areas in buildings or outside; and (4) compatibility of killing regimens with the: (i) presence of people; (ii) food quality; (iii) presence of significant amounts of organic matter; and (iv) minimal damage to equipment in the decontamination zone. This review will summarize research on spore killing and point out some common flaws which can make results from spore killing research questionable.

Elevated temperatures drive abiotic and biotic degradation of organic matter in a peat bog under oxic conditions

2022 ◽  
Vol 804 ◽  
pp. 150045
Author(s):  
Roya AminiTabrizi ◽  
Katerina Dontsova ◽  
Nathalia Graf Grachet ◽  
Malak M. Tfaily
Keyword(s):  
Organic Matter ◽  
Elevated Temperatures ◽  
Peat Bog ◽  
Biotic Degradation

scholarly journals Temperature and UV light affect the activity of marine cell-free enzymes

2017 ◽  
Vol 14 (17) ◽  
pp. 3971-3977 ◽  
Author(s):  
Blair Thomson ◽  
Christopher David Hepburn ◽  
Miles Lamare ◽  
Federico Baltar
Keyword(s):  
Organic Matter ◽  
Extracellular Enzymes ◽  
Elevated Temperatures ◽  
Uv Light ◽  
Control Mechanisms ◽  
Potential Control ◽  
Control Factors ◽  
Rate Limiting Step ◽  
Ocean Environment ◽  
First Time

Abstract. Microbial extracellular enzymatic activity (EEA) is the rate-limiting step in the degradation of organic matter in the oceans. These extracellular enzymes exist in two forms: cell-bound, which are attached to the microbial cell wall, and cell-free, which are completely free of the cell. Contrary to previous understanding, cell-free extracellular enzymes make up a substantial proportion of the total marine EEA. Little is known about these abundant cell-free enzymes, including what factors control their activity once they are away from their sites (cells). Experiments were run to assess how cell-free enzymes (excluding microbes) respond to ultraviolet radiation (UVR) and temperature manipulations, previously suggested as potential control factors for these enzymes. The experiments were done with New Zealand coastal waters and the enzymes studied were alkaline phosphatase (APase), β-glucosidase, (BGase), and leucine aminopeptidase (LAPase). Environmentally relevant UVR (i.e. in situ UVR levels measured at our site) reduced cell-free enzyme activities by up to 87 % when compared to controls, likely a consequence of photodegradation. This effect of UVR on cell-free enzymes differed depending on the UVR fraction. Ambient levels of UV radiation were shown to reduce the activity of cell-free enzymes for the first time. Elevated temperatures (15 °C) increased the activity of cell-free enzymes by up to 53 % when compared to controls (10 °C), likely by enhancing the catalytic activity of the enzymes. Our results suggest the importance of both UVR and temperature as control mechanisms for cell-free enzymes. Given the projected warming ocean environment and the variable UVR light regime, it is possible that there could be major changes in the cell-free EEA and in the enzymes contribution to organic matter remineralization in the future.

scholarly journals Diamondoids and Thiadiamondoids Generated From Hydrothermal Pyrolysis of Crude Oil and TSR Experiments

2021 ◽  
Author(s):  
Yanyan Peng ◽  
Chunfang Cai ◽  
Chenchen Fang ◽  
Liangliang Wu ◽  
Jinzhong Liu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Crude Oil ◽  
Elevated Temperatures ◽  
Source Rocks ◽  
Chemical Alteration ◽  
Thermal Maturation ◽  
Direct Reactions ◽  
New Generation ◽  
Oil Cracking ◽  
New Formula

Abstract Diamondoid compounds are widely used to reflect thermal maturation of high mature source rocks or oils and oil cracking extents. However, diamondoids and thiadiamondoids were demonstrated to have newly been generated and decomposed in our hydrothermal pyrolysis of crude oil and TSR experiments. Our results show that adamantanes and diamantanes are generated primarily within the maturity range 0.48–2.1% and 1.2–3.0% EasyRo, respectively. Their formation is enhanced and the decomposition of diamantanes obviously lags behind at elevated temperatures compared with anhydrous experiments. MDI, EAI, DMAI-1, DMDI-2 may serve as reliable maturity proxies at > ca.1.0% EasyRo, and other isomerization indices (TMAI-1, TMAI-2 and DMAI-2) are effective for the highly mature organic matter at EasyRo > 2.0%. The extent of oil cracking (EOC) calculated from the broadly used 3-+4-MD method (Dahl et al., 1999) is proven to overestimate, especially for highly cracked samples due to the new generation of 3-+4-MD. Still, it can be corrected using a new formula at <3.0% EasyRo. Other diamondoid-related indices (e.g. EAI, DMDI-2, As/Ds, MAs/MDs, DMAs/DMDs, and DMAs/MDs) can also be used to estimate EOC. However, these indices cannot be applied to TSR-altered petroleum. TSR is experimentally confirmed to generate diamantanes and thiaadmantanes at 1.81% EasyRo via direct reactions of reduced S species with hydrocarbons and accelerate the decomposition of diamantanes at > 3.0% EasyRo compared with thermal chemical alteration (TCA).

scholarly journals An Artificial Intelligence Approach Toward Food Spoilage Detection and Analysis

2022 ◽  
Vol 9 ◽  
Author(s):  
Ekta Sonwani ◽  
Urvashi Bansal ◽  
Roobaea Alroobaea ◽  
Abdullah M. Baqasah ◽  
Mustapha Hedabou
Keyword(s):  
Shelf Life ◽  
Food Quality ◽  
Food Spoilage ◽  
Sensors And Actuators ◽  
Food Grains ◽  
Alert Message ◽  
New Methodologies ◽  
Quality Of Food ◽  
Intelligence Approach

Aiming to increase the shelf life of food, researchers are moving toward new methodologies to maintain the quality of food as food grains are susceptible to spoilage due to precipitation, humidity, temperature, and a variety of other influences. As a result, efficient food spoilage tracking schemes are required to sustain food quality levels. We have designed a prototype to track food quality and to manage storage systems at home. Initially, we have employed a Convolutional Neural Network (CNN) model to detect the type of fruit and veggies. Then the proposed system monitors the gas emission level, humidity level, and temperature of fruits and veggies by using sensors and actuators to check the food spoilage level. This would additionally control the environment and avoid food spoilage wherever possible. Additionally, the food spoilage level is informed to the customer by an alert message sent to their registered mobile numbers based on the freshness and condition of the food. The model employed proved to have an accuracy rate of 95%. Finally, the experiment is successful in increasing the shelf life of some categories of food by 2 days.

scholarly journals Facile synthesis of graphene wool doped with oleylamine-capped silver nanoparticles (GW-αAgNPs) for water treatment applications

2021 ◽  
Vol 11 (11) ◽  
Author(s):  
Adedapo O. Adeola ◽  
Gugu Kubheka ◽  
Evans M. N. Chirwa ◽  
Patricia B. C. Forbes
Keyword(s):  
Silver Nanoparticles ◽  
Organic Matter ◽  
Adsorption Capacity ◽  
Natural Organic Matter ◽  
Elevated Temperatures ◽  
Maximum Adsorption Capacity ◽  
Facile Synthesis ◽  
Gram Positive ◽  
Gram Negative ◽  
Process Economics

AbstractThe facile synthesis of graphene wool doped with oleylamine-capped silver nanoparticles (GW-αAgNP) was achieved in this study. The effect of concentration, pH, temperature and natural organic matter (NOM) on the adsorption of a human carcinogen (benzo(a)pyrene, BaP) was evaluated using the doped graphene wool adsorbent. Furthermore, the antibacterial potential of GW-αAgNP against selected drug-resistant Gram-negative and Gram-positive bacteria strains was evaluated. Isotherm data revealed that adsorption of BaP by GW-αAgNP was best described by a multilayer adsorption mechanism predicted by Freundlich model with least ERRSQ < 0.79. The doping of graphene wool with hydrophobic AgNPs coated with functional moieties significantly increased the maximum adsorption capacity of GW-αAgNP over GW based on the qmax and qm predicted by Langmuir and Sips models. π-π interactions contributed to sorbent-sorbate interaction, due to the presence of delocalized electrons. GW-αAgNP-BaP interaction is a spontaneous exothermic process (negative $$\Delta H^\circ$$ Δ H ∘ and $$\Delta G)$$ Δ G ) , with better removal efficiency in the absence of natural organic matter (NOM). While GW is more feasible with higher maximum adsorption capacity (qm) at elevated temperatures, GW-αAgNP adsorption capacity and efficiency is best at ambient temperature, in the absence of natural organic matter (NOM), and preferable in terms of energy demands and process economics. GW-αAgNP significantly inhibited the growth of Gram-negative Pseudomonas aeruginosa and Gram-positive Bacillus subtilis strains, at 1000 mg/L dosage in preliminary tests, which provides the rationale for future evaluation of this hybrid material as a smart solution to chemical and microbiological water pollution.

The influence of stream size on the food quality of seston

1983 ◽  
Vol 61 (9) ◽  
pp. 1995-2010 ◽  
Author(s):  
Robert J. Naiman
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Food Quality ◽  
Dry Mass ◽  
Fine Particulate Organic Matter ◽  
Respiration Rates ◽  
Fine Particulate ◽  
Order Of Magnitude ◽  
Nitrogen Ratio

During 1979 and 1980, seston was investigated for food quality in five Quebec streams ranging in size from first to ninth order. Course particulate organic matter (CPOM; > 1 mm), fine particulate organic matter (FPOM; 53 μm – 1 mm), and very fine particulate organic matter (VPOM; 0.5–53 μm) were examined for the percentage of organic matter, the carbon to nitrogen ratio, the amount of chlorophyll a, the respiration rate of associated microbes, and the nature of the particles. The percentage of organic matter ranged from 42 to 64% for CPOM, 21 to 35% for FPOM, and 32 to 82% for VPOM. The majority of chlorophyll was associated with FPOM and CPOM, but chlorophyll-bearing particles constituted only 6–34% ([Formula: see text]) of the seston load. Highest respiration rates ([Formula: see text] mg O2∙g ash-free dry mass−1∙h−1) were associated with VPOM, nearly an order of magnitude greater than mean rates associated with FPOM or CPOM. Carbon to nitrogen ratios decreased with particle size, and the lowest ratios and highest percentage of nitrogen were found in the large rivers. Electron microscopy indicated a more diverse array of particles downstream. The results suggest that seston undergoes rapid and directed changes in food quality as particles move downstream.

scholarly journals Diamondoids and thiadiamondoids generated from hydrothermal pyrolysis of crude oil and TSR experiments

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Yanyan Peng ◽  
Chunfang Cai ◽  
Chenchen Fang ◽  
Liangliang Wu ◽  
Jinzhong Liu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Crude Oil ◽  
Elevated Temperatures ◽  
Source Rocks ◽  
Natural Conditions ◽  
Chemical Alteration ◽  
Direct Reactions ◽  
New Generation ◽  
Oil Cracking ◽  
New Formula

AbstractDiamondoid compounds are widely used to reflect thermal maturation of high mature source rocks or oils and oil cracking extents. However, diamondoids and thiadiamondoids were demonstrated to have newly been generated and decomposed in our hydrothermal pyrolysis of crude oil and TSR experiments. Our results show that adamantanes and diamantanes are generated primarily within the maturity range 0.48–2.1% and 1.2–3.0% EasyRo, respectively. Their formation is enhanced and the decomposition of diamantanes obviously lags at elevated temperatures compared with anhydrous experiments. MDI, EAI, DMAI-1, DMDI-2 may serve as reliable maturity proxies at > ca.1.0% EasyRo, and other isomerization indices (TMAI-1, TMAI-2 and DMAI-2) are effective for the highly mature organic matter at EasyRo > 2.0%. The extent of oil cracking (EOC) calculated from the broadly used (3- + 4-) MD method (Dahl et al. in Nature 399:54–56, 1999) is proven to overestimate, especially for highly cracked samples due to the new generation of (3- + 4-) MD. Still, it can be corrected using a new formula at < 3.0% EasyRo. Other diamondoid-related indices (e.g., EAI, DMDI-2, As/Ds, MAs/MDs, DMAs/DMDs, and DMAs/MDs) can also be used to estimate EOC. However, these indices cannot be applied to TSR-altered petroleum. TSR is experimentally confirmed to generate diamantanes and thiaadmantanes at 1.81% EasyRo likely via direct reactions of reduced S species with hydrocarbons and accelerate the decomposition of diamantanes at > 2.62% EasyRo compared with thermal chemical alteration (TCA). More studies are needed to assess specific mechanisms for the formation of thiadiamondoids under natural conditions.

qPCR as a powerful tool for microbial food spoilage quantification: Significance for food quality

2011 ◽  
Vol 22 (7) ◽  
pp. 367-376 ◽  
Author(s):  
Noelia Martínez ◽  
Maria Cruz Martín ◽  
Ana Herrero ◽  
María Fernández ◽  
Miguel A. Alvarez ◽  
...  
Keyword(s):  
Food Quality ◽  
Food Spoilage

scholarly journals Enhanced decomposition offsets enhanced productivity and soil carbon accumulation in coastal wetlands responding to climate change

2011 ◽  
Vol 8 (4) ◽  
pp. 987-993 ◽  
Author(s):  
M. L. Kirwan ◽  
L. K. Blum
Keyword(s):  
Organic Matter ◽  
Soil Carbon ◽  
Sea Level Rise ◽  
Sea Level ◽  
Elevated Co2 ◽  
Coastal Wetlands ◽  
Elevated Temperatures ◽  
Carbon Accumulation ◽  
Measured Temperature ◽  
Elevated Co2 And Temperature

Abstract. Coastal wetlands are responsible for about half of all carbon burial in oceans, and their persistence as a valuable ecosystem depends largely on the ability to accumulate organic material at rates equivalent to relative sea level rise. Recent work suggests that elevated CO2 and temperature warming will increase organic matter productivity and the ability of marshes to survive sea level rise. However, we find in a series of preliminary experiments that organic decomposition rates increase by about 20% per degree of warming. Our measured temperature sensitivity is similar to studies from terrestrial systems, three times as high as the response of salt marsh productivity to temperature warming, and greater than the productivity response associated with elevated CO2 in C3 marsh plants. Although the experiments were simple and of short duration, they suggest that enhanced CO2 and warmer temperatures could actually make marshes less resilient to sea level rise, and tend to promote a release of soil carbon. Simple projections indicate that elevated temperatures will increase rates of sea level rise more than any acceleration in organic matter accumulation, suggesting the possibility of a positive feedback between climate, sea level rise, and carbon emissions in coastal environments.

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