• Journal of Biosystems Engineering
• /
• v.41 no.3
• /
• pp.240-254
• /
• 2016

Background: Foodborne pathogens are a growing concern with respect to human illnesses and death. There is an increasing demand for improvements in global food safety. However, it is a challenge to detect and identify these harmful organisms in a rapid, responsive, suitable, and effective way. Results: Rapid developments in biosensor designs have contributed to the detection of foodborne pathogens and other microorganisms. Biosensors can automate this process and have the potential to enable fast analyses that are cost and time-effective. Various biosensor techniques are available that can identify foodborne pathogens and other health hazards. Conclusions: In this review, biosensor technology is briefly discussed, followed by a summary of foodborne pathogen detection using various transduction systems that exhibit specificity for particular foodborne pathogens. In addition, the recent application of biosensor technology to detect pesticides and heavy metals is briefly addressed.

• Journal of Dairy Science and Biotechnology
• /
• v.33 no.2
• /
• pp.139-151
• /
• 2015

Biofilms are aggregates of microorganisms present in a self-produced matrix of extracellular polymeric substance (EPS) adhered to a surface. Formation of a biofilm in the environment on farms and in dairy plants comprises several stages: attachment, growth (development), and detachment. Generally, biofilms are harmful to humans and need to be controlled. Stainless steel (SS) surfaces that are untreated or are scratched comprise substrata that are especially vulnerable to biofilm formation; therefore, SS surfaces should be polished and sanitized. Various approaches are available for the destruction of biofilms; cleaning-in-place (CIP) is the method mainly used in dairy plants. Further study on optimum detergents, cleaning conditions, and methods for this purpose is needed.

• Journal of the Korean Applied Science and Technology
• /
• v.21 no.4
• /
• pp.327-334
• /
• 2004

Cysteine-silver complexes were prepared and investigated the antimicrobial activity on rubber mat manufactured with waste rubber. We are exposed to harmful bacteria and fungi all the time. We manufactured antimicrobial mat to be imposed to mats that it can prevent generation of bacteria and microorganisms, and restrict their reproduction. Infection of medical devices causes significant morbidity and mortality. For aim of this study, we measured the antimicrobial mat manufactured with cysteine-Ag complex by CCD, FT-IR and NMR. The effect of mole ratio of cysteine-Ag complex on antimicrobial activity to bacteria and fungi is investigated. Reduction rate is evaluated using the Quinn method. Antimicrobial activity of complex on mole ratio 1:4 was effectively inhibited. The complexes had a better antibacterial activity than antifungal activity on rubber mat.

• Journal of Navigation and Port Research
• /
• v.28 no.10 s.96
• /
• pp.955-960
• /
• 2004

The treated ballast water from previous treatment contains microorganisms and pathogenic organisms in an electrolytic treatment system. The experimental methods included using a peristaltic flow pump placed upward on an electrode pole. Due to the reaction time, the hydraulic retention time indicated unlike microorganisms on the flow rate. In electrolysis, dioxide iridium-coated titanium (Ti/Ir02) and stainless steel plates were used for the anode and cathode, respectively. Current density controls make use of a DC power supply on 250V, 100Amper. Experimental use of a current density between 0.1 and 1.0A/dm2 was able to disinfect the microorganism (E. coli, Bacteria, Bacillus sp.) in seawater for 5 seconds of reaction time. The removal rate was approximately $90\%,$ while the current density was 2.0A/dm2 and the electrode distance was 75mm. This study shows that the electrolytic treatment system has a potential for the sterilization of ballast water.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.50 no.4
• /
• pp.335-342
• /
• 2017

Oysters Crassostrea gigas are a globally popular shellfish for human consumption. As filter-feeding bivalve mollusks, oysters may harbor many microorganisms and chemicals that could pose potential human health risks. The objective of this study was to investigate the suitability of cultured oysters for raw consumption or use in seafood products by measuring concentrations of harmful microorganisms and chemicals in their flesh. Microbial concentrations in cultured oysters were found to be: $1.0{\times}10^2-6.0{\times}10^4CFU/g$ (viable cell counts), not detected $(ND)-5.4{\times}10^3CFU/g$ (coliform bacteria), $ND-1.3{\times}10^2CFU/g$ (E. coli), and $ND-4.6{\times}10^3CFU/g$ (Vibrio parahaemolyticus). Other pathogenic bacteria, including Enterohemorrhagic E. coli (EHEC), Listeria monocytogenes, Staphylococcus aureus, and Salmonella spp., were not detected in any samples. Heavy metal concentrations of cultured oysters were ND-0.239 mg/kg (total mercury), ND-1.091 mg/kg (lead), ND-0.968 mg/kg (cadmium). The concentrations of benzo(a)pyrene ranged from $0.280-0.880{\mu}g/kg$. Paralytic shellfish poison ranged from ND-0.58 mg/kg, while diarrhetic shellfish poison was not detected. No radioactivity was detected. These results suggest that oysters intended for raw consumption or use in seafood products should be subjected to chemical and biological controls.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.12
• /
• pp.1657-1667
• /
• 2010

Direct-fed microbials (DFM) are dietary supplements that inhibit gastrointestinal infection and provide optimally regulated microbial environments in the digestive tract. As the use of antibiotics in ruminant feeds has been banned, DFM have been emphasized as antimicrobial replacements. Microorganisms that are used in DFM for ruminants may be classified as lactic acid producing bacteria (LAB), lactic acid utilizing bacteria (LUB), or other microorganisms including species of Lactobacillus, Bifidobacterium, Enterococcus, Streptococcus, Bacillus and Propionibacterium, strains of Megasphaera elsdenii and Prevotella bryantii and yeast products containing Saccharomyces and Aspergillus. LAB may have beneficial effects in the intestinal tract and rumen. Both LAB and LUB potentially moderate rumen conditions and improve feed efficiency. Yeast DFM may reduce harmful oxygen, prevent excess lactate production, increase feed digestibility, and improve fermentation in the rumen. DFM may also compete with and inhibit the growth of pathogens, stimulate immune function, and modulate microbial balance in the gastrointestinal tract. LAB may regulate the incidence of diarrhea, and improve weight gain and feed efficiency. LUB improved weight gain in calves. DFM has been reported to improve dry matter intake, milk yield, fat corrected milk yield and milk fat content in mature animals. However, contradictory reports about the effects of DFM, dosages, feeding times and frequencies, strains of DFM, and effects on different animal conditions are available. Cultivation and preparation of ready-to-use strict anaerobes as DFM may be cost-prohibitive, and dosing methods, such as drenching, that are required for anaerobic DFM are unlikely to be acceptable as general on-farm practice. Aero-tolerant rumen microorganisms are limited to only few species, although the potential isolation and utilization of aero-tolerant ruminal strains as DFM has been reported. Spore forming bacteria are characterized by convenience of preparation and effectiveness of DFM delivery to target organs and therefore have been proposed as DFM strains. Recent studies have supported the positive effects of DFM on ruminant performance.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.175.1-175.1
• /
• 2016

In recent, tract infections such as atopic dermatitis, allergic rhinitis and a respiratory disease are increasing, giving rise to the atmospheric pollution, inflow of micro-size dust and side effect of humidifier disinfectant. In this context, the environment-friendly technology is required to eliminate airborne pathogens. We propose solution of the previous problems, making use of Radical Mist Generator (RMG). Existing technologies of air purification using a gas discharge produce harmful substances such as ozone, NOx, etc. However, the RMG uses a pure water as a plasma forming material. The RMG sprays the water mist, which contains reactive radicals to sterilize microorganisms. RMG is comprised of a power supply, plasma electrodes and a nozzle. In order to analyze the electrical characteristic and concentrations of reactive radicals, we employ an oscilloscope and a titration method. To test the sterilization effect of RMG, we used E.coli. We confirmed that E.coli was killed over 90%. Eventually, we expect that RMG can be promising tool for a purified system.

• Proceedings of the KIEE Conference
• /
• 1997.07f
• /
• pp.2162-2164
• /
• 1997

High Voltage High Current Pulsed Electric Fields (HVHC-PEF) is a promising technology for the non-thermal pasteurization of foods and a sound complement or replacement to traditional thermal pasteurization, which inactivates bacteria and other microorganisms harmful to humans, but also degrades color, flavor, texture and nutrients. Foods can be pasteurized with pulsed electric fields at ambient or refrigerated temperatures for a short treatment time of seconds or less and the fresh-like quality of food is preserved. Although successful in laboratory tests, applying HVHC-PEF to food pasteurization on a large scale presents many unresolved engineering problems. In this paper the design considerations for 25kV 1kA class HVHC-PEF pasteurization equipment are analyzed and experimental results are discussed.

• Korean Journal of Environmental Biology
• /
• v.19 no.2
• /
• pp.101-105
• /
• 2001

The biodeterioration with blue-green algae has been studied since 1997 up to 2000 in the tomb of King Mooryong in Kongiu, Korea. Biodeterioration in the tomb initially started from the formation of micro-organismic biofilm that had been suggested to make minor changes on the stone surface. This study revealed that the biofilm formed by microorganisms could result in permanent damages on stone cultural properties. The application of a chemical, 'K2Ol', developed by the author successfully removed fouling of biofilm on the surfaces of stone cultural properties. When small pieces of granite stone were embedded in the solution to study the side effects of the chemicals for a period of three months, the mechanical stability was 0.97 compared to control and there was no change in color. Biodeterioration is one of the most harmful factors that decrease the value of stone cultural properties but it may be treated with a development of proper chemicals.

• Journal of Yeungnam Medical Science
• /
• v.3 no.1
• /
• pp.387-393
• /
• 1986

Antiseptics are substances that kill or prevent the growth of microorganisms when applied to living tissue. They must be effective against microoranisms but must also retain their activity in presence of body fluids without being harmful locally or systemically. Among many antiseptics. $Betadine^{(R)}$ has been widely used because of its low toxicity and high germicidal efficacy. We reported 2 cases of allergic contact dermatitis to $Betadine^{(R)}$ in surgical patients. They had eczematous eruption along the $Betadine^{(R)}$ applying sites. Patch tests with $Betadine^{(R)}$ confirmed the diagnosis.