• Journal of Microbiology and Biotechnology
• /
• v.33 no.7
• /
• pp.895-908
• /
• 2023

Disposal of waste containing heavy metals into the environment is a major threat to human health and can result in toxic or chronic poisoning in aquatic life. In the current study, metal-resistant Raoultella ornithinolytica was isolated from metal-contaminated samples collected from the Tanjaro River, located southwest of Sulaymaniyah, Iraq. R. ornithinolytica was identified by partial amplification of 16S rRNA. The uptake potency of heavy metals was assessed using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and indicated that R. ornithinolytica removed 67, 89, 63.4, 55.6, 56.5, 65, and 61.9% of Cd, Pb, Cr, Ni, Zn, Co, and Fe, respectively. These removal rates were influenced by temperature, pH, and contact time; at 35℃ and pH 5 with a change in the incubation time, the reduction rate improved from 89 to 95% for Pb, from 36.4 to 45% for Cu, and from 55.6 to 64% for Ni. Gene analysis indicated that R. ornithinolytica contained pbrT, chrB, nccA, iroN, and czcA genes, but the pcoD gene was absent. Energy-dispersive X-ray spectroscopy (EDS) images showed evidence of metal ion binding on the cell wall surface with different rates of binding. Transmission electron microscopy (TEM) detected different mechanisms for metal particle localization; cell surface adsorption was the main mechanism for Pb, Zn, and Co uptake, while Cd, Ni, and Fe were accumulated inside the cell. The current study describes, for the first time, the isolation of R. ornithinolytica from metal-contaminated water, which can be used as an eco-friendly biological expedient for the remediation and detoxification of metals from contaminated environments.

• Journal of Food Hygiene and Safety
• /
• v.25 no.4
• /
• pp.367-375
• /
• 2010

The bacteriological and physiochemical analysis of sea water and sediments in Tongyeong harbor was conducted to evaluate sanitary conditions. The samples were collected at 8 stations established once a month from June, 2008 to May, 2009. During the study period, the range of temperature was from 6.7 to $25.2^{\circ}C$, transparency ranged from 1.2 to 2.6 m, chemical oxygen demand ranged from 1.90 to 2.92 mg/L, dissolved oxygen ranged from 6.2 to 10.5 mg/L, dissolved nitrogen ranged from 0.052 to 0.098 mg/L, phosphate ranged from 0.044 to 0.065 mg/L, respectively. Seafood, if eaten raw, carries the risk of food poisoning. Seafood poisoning is often cause by pathogenic microorganism originating from fecal contamination, such as Salmonella sp., Shigella sp. and norovirus. Fecal coliforms are an important indicator of fecal contamination. Therefore, data on fecal coliform are very important for evaluating the safety of fisheries in coastal areas. So, we investigated the sanitary indicate bacteria. The coliform group and fecal coliform MPN's of sea water in Tongyeong harbor were ranged from < 1.8~22,000/100 mL (GM 164.9 MPN/100 mL) and < 1.8~7,900 MPN/100 mL (GM 33.7 MPN/100 mL), respectively. Total coliform were detected 97.0% in 96 of samples and 68.9% of total coliforms were fecal coliforms. These results similar to another seawater detection ratio of total coloforms and fecal coliforms. The Vibrios was isolated and identified with VITEK system. Four hundred eighty strains that were obtained from sea water samples in Tongyeong harbor Detection ratio Vibrio alginolyticus, 34.2%, Vibrio parahaemolyticus, 13.8%, Vibrio vulnificus 10.0%, and V. mimicus 12.5% respectively. Vibrio cholerae O1, was not detected. During the study period, the ranges of water content, ignition loss, COD, and acid volatile sulfates in sediments in Tongyeoung harbor were 41.0~57.4%, 7.8~10.5%, 6.51~9.30 mg/g, 0.04~0.09 mg/g, respectively. Heavy metals in sediment of Tongyeoung harbor were Cd, $0.10{\pm}0.05$; Cu, $4.79{\pm}8.20$; As, $1.95{\pm}0.17$; Hg, $0.10{\pm}0.07$; $Cr^{6+}$, $0.34{\pm}0.12$; Zn, $125.33{\pm}16.40$; Ni, $16.43{\pm}1.93$ mg/kg.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.3
• /
• pp.342-350
• /
• 2005

In the present work antidotal effect of dietary garlic was studied on lead-intoxicated rat. One of 5 groups of young Wistar sp. male rat, aged 4 weeks for control were fed only normal diet. Lead (25 ㎎/㎏.bw/week) was administered to other four groups for plumbism model over 4 weeks, of which three groups were supplemented with one of the following raw garlic juice: 1.10 (1% diet), 2.21 (2%) and 3.31 (3%) ㎎/㎏.bw/day respectively. Body weight gain rates in all garlic group significantly increased, especially in 2% garlic group that showed 9.8% net gain, as compared with only-lead treated group but lower values than control. The fecal and urinary lead excretion in all garlic groups significantly increased in a dose dependent fashion with highest value of 9.59% net gain in 3% garlic group as compared to lead treated control group. In comparison with lead treated control group, all garlic groups showed significantly increased hemoglobin contents, hematocrit values (Hct), red blood cell (RBC) count, mean corpuscular volume (MCV), and δ-amino levulinic acid dehydratase (δ-ALAD) activities. The values of 2% and 3% garlic groups remarkably increased while no significant difference between the values of 2% and 3% garlic groups was observed. The ALT activities, blood urea nitrogen (BUN) and creatinine (CR) in all garlic groups significantly decreased as compared with lead-treated control group. The values of 2% garlic group were the lowest and significantly different from the values of 1% and 3% garlic groups. The results showed that 2%-3% garlic juice in diet had obviously antidotal effects in lead-poisoned rats by promoting lead excretion. However, mega dose garlic such as in 3% garlic group might have some adverse effects on hepatic and renal functions in rats. In conclusion, the dietary habit to take ordinary garlic sauce in appropriate amount, may be helpful for preventing lead or other heavy metal intoxication.

• Journal of Food Hygiene and Safety
• /
• v.29 no.1
• /
• pp.31-39
• /
• 2014

Norovirus causes acute gastroenteritis in all age groups and its food poisoning outbreaks are rapidly increasing in Korea. Reverse transcription-polymerase chain reaction (RT-PCR) is most widely used for the rapid detection of foodborne viruses due to high sensitivity. However, the false positive results of RT-PCR obtained against already inactivated viruses could be a serious drawbacks in food safety area. In this study, we investigated a method to yield true positive RT-PCR results only with alive viruses. To decompose the RNA genes from dead viruses, the enzymatic treatments composed of proteinse K and Ribonuclease A were applied to the sanitized and inactivated virus particles. Another aim of this study was to quantify the efficiencies of several major sanitizing treatments using real-time RT-PCR. Feline calicivirus (FCV) that belongs to the same Caliciviridae family with norovirus was used as a surrogate model for norovirus. The initial level of virus in control suspension was approximately $10^4$ PFU/mL. Most of inactivated viruses treated with the enzymatic treatment for 30 min at $37^{\circ}C$ were not detected in RT-PCR, Quantification results to verify the inactivation efficiencies of sanitizing treatments using real-time RT-PCR showed no false positive in most cases. We could successfully develope a numerical quantification process for the inactivated viruses after major sanitizing treatments using real-time RT-PCR. The results obtained in this study could provide a novel basis of rapid virus quantification in food safety area.

• Journal of agriculture & life science
• /
• v.46 no.3
• /
• pp.97-108
• /
• 2012

Physical, chemical and biological hazards of strawberry farms at the cultivation stage were analyzed to establish the GAP(Good Agricultural Practice) system. Samples were collected from the plants, cultivation environments(water, soil and air), and personal hygiene (hand, glove, and clothes) of three strawberry farms(A, B, and C) and were tested to analyze physical, chemical (heavy metals and pesticide residues), and biological(sanitary indications and foodborne pathogens) hazards. Physical hazards such as insects and pieces of metal and glass were found in the strawberry farms and can be potential bow for strawberry products. Heavy metal and pesticide residue as chemical hazards were detected at levels lower than the regulation limit. In case of biological hazards, total bacteria and coliform were detected at the levels of 1.6~7.3 and 1.3~5.6 log CFU/g, leaf, mL, hand or $100cm^2$. However, Escherichia coli was not detected in all samples. Bacillus cereus and Staphylococuus aureus were detected at levels of ${\leq}$ 1.1~6.1 log CFU and 4.7~5.4 log CFU/g, mL, hand or $100cm^2$, whereas Listeria monocytogenes, E. coli O157 and Salmonella spp. were not detected in all samples. This study demonstrates that various harzards were in strawberry farms at the growing stage. Therefore proper management such as GAP is needed to prevent the occurrence of food poisoning associated with the hazards revealed in this study.