• Title/Summary/Keyword: E. coli concentration

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Susceptibility of Anthonomus grandis (Cotton Boll Weevil) and Spodoptera frugiperda (Fall Armyworm) to a Cry1Ia-type Toxin from a Brazilian Bacillus thuringiensis Strain

  • Grossi-De-Sa, Maria Fatima;De Magalhaes, Mariana Quezado;Silva, Marilia Santos;Silva, Shirley Margareth.Buffon;Dias, Simoni Campos;Nakasu, Erich Yukio Tempel;Brunetta, Patricia Sanglard Felipe;Oliveira, Gustavo Ramos;De Oliveira Neto, Osmundo Brilhante;De Oliveira, Raquel Sampaio;Soares, Luis Henrique Barros;Ayub, Marco Antonio Zachia;Siqueira, Herbert Alvaro Abreu;Figueira, Edson L.Z.
    • BMB Reports
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    • v.40 no.5
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    • pp.773-782
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    • 2007
  • Different isolates of the soil bacterium Bacillus thuringiensis produce multiple crystal (Cry) proteins toxic to a variety of insects, nematodes and protozoans. These insecticidal Cry toxins are known to be active against specific insect orders, being harmless to mammals, birds, amphibians, and reptiles. Due to these characteristics, genes encoding several Cry toxins have been engineered in order to be expressed by a variety of crop plants to control insectpests. The cotton boll weevil, Anthonomus grandis, and the fall armyworm, Spodoptera frugiperda, are the major economically devastating pests of cotton crop in Brazil, causing severe losses, mainly due to their endophytic habit, which results in damages to the cotton boll and floral bud structures. A cry1Ia-type gene, designated cry1Ia12, was isolated and cloned from the Bt S811 strain. Nucleotide sequencing of the cry1Ia12 gene revealed an open reading frame of 2160 bp, encoding a protein of 719 amino acid residues in length, with a predicted molecular mass of 81 kDa. The amino acid sequence of Cry1Ia12 is 99% identical to the known Cry1Ia proteins and differs from them only in one or two amino acid residues positioned along the three domains involved in the insecticidal activity of the toxin. The recombinant Cry1Ia12 protein, corresponding to the cry1Ia12 gene expressed in Escherichia coli cells, showed moderate toxicity towards first instar larvae of both cotton boll weevil and fall armyworm. The highest concentration of the recombinant Cry1Ia12 tested to achieve the maximum toxicities against cotton boll weevil larvae and fall armyworm larvae were 230 ${\mu}g/mL$ and 5 ${\mu}g/mL$, respectively. The herein demonstrated insecticidal activity of the recombinant Cry1Ia12 toxin against cotton boll weevil and fall armyworm larvae opens promising perspectives for the genetic engineering of cotton crop resistant to both these devastating pests in Brazil.

Enzymatic synthesis of benzyl alcohol galactoside using Escherichia coli β-galactosidase (대장균 β-galactosidase를 이용한 benzyl alcohol galactoside의 합성 연구)

  • Jung, Kyung-Hwan
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.2
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    • pp.572-580
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    • 2019
  • Recently, it has been reported that benzyl alcohol (BzOH) as an additive in cosmetics, food, and medicine lead to toxicity and allergy problem. Then, to circumvent this hurdle, we carried out the synthesis of benzyl alcohol galactoside (BzO-gal). Previously, it was confirmed that BzO-gal was synthesized by transgalactosylation reaction using Escherichia coli (E. coli) ${\beta}$-galactosidase (${\beta}-gal$). Meanwhile, in this study, two peaks of BzO-gal as sodium adduct ion (m/z=293.1004) and protonated ion (m/z=271.1180) were detected in the reaction mixture by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS). In addition, the amount of ${\beta}-gal$ and BzOH concentration, temperature, pH, and lactose concentration, respectively, were optimized (${\beta}-gal$, 0.75 U/mL; BzOH, 185 mM; temperature, $40^{\circ}C$, pH, 7.5; lactose, 350 g/l). Under these optimal conditions, 185 mM BzOH was converted into about 131 mM BzO-gal, in which the conversion yield was about 72%. In the future, BzO-gal will be applicable as a substitute for BzOH as a less toxic preservative for the cosmetic, pharmaceutical, and food industries, and we are planning to investigate the characteristics of BzO-gal as a preservative.

Change of Harmful Micnoorganisms in Pickling Process of Salted Cabbage According to Salting and Washing Conditions (배추김치의 절임공정 조건에 따른 위해미생물 변화)

  • Kim, Jin-Hee;Lee, Yu-Keun;Yang, Ji-Young
    • Journal of Food Hygiene and Safety
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    • v.26 no.4
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    • pp.417-423
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    • 2011
  • Salted Cabbage products purchased from different companies at 4 different districts in South Korea were detected in this study. Cabbage and salt are the main materials for kimchi manufacture. The results of general bacteria contaminated in the samples were $1.4{\times}10^5$, $6.4{\times}10^5$, $1.7{\times}10^7$, $3.6{\times}10^7$ CFU/g in cabbage and $2.7{\times}10^3$ CFU/g in salt, respectively. The results of coliforms were detected as $2.4{\times}10^4$ CFU/g, and there was no Escherichia coli in any sample. Staphylococcus aureus was detected in cabbage as $9.9{\times}10^2$, $8.0{\times}10^1$, and $3.0{\times}10^3$ CFU/g, Bacillus cereus was also found in cabbage as $4.1{\times}10^3$ and $1.0{\times}10^1$ CFU/g. The results of Campylobacter jejuni and Vibrio paraheamolyticus were $2.4{\times}10^6$ and $1.0{\times}10^4$ CFU/g in cabbage, respectively. $1.0{\times}10^3$ CFU/g for Yersinia enterocolitica was determined in salt. In case of Listeria monocytogenes, the results were $1.5{\times}10^1$, $1.1{\times}10^2$, and $4.5{\times}10^1$ CFU/g in cabbage. Total batcteria ranged from $1.4{\times}10^1$ to $4.4{\times}10^5$ CFU/g were detected in salting solution, from $1.5{\times}10^4$ to $1.2{\times}10^8$ CFU/g in dehydrated salted-cabbage, from $9.4{\times}10^4{\sim}1.3{\times}10^8$ CFU/g in minced salted-cabbage. The results of E. coli in samples from different companies were different from one to anther. The results of the contamination of S. aureus and B. cereus showed positive in salting solution and dehydrated salted-cabbage at a portion of companies. V. paraheamolyticus was detected in salting solution. The contamination of Y. enterocolitica ranged from $9.5{\times}10^2$ to $1.8{\times}10^3$ CFU/g in salting solution, from $1.7{\times}10^1$ to $2.7{\times}10^2$ CFU/g in dehydrated salted-cabbage, from $1.2{\times}10^2$ to $1.3{\times}10^8$ CFU/g in minced salted-cabbage. The contamination of L. monocytogenes ranged from $8.0{\times}10^2$ to $1.7{\times}10^4$ CFU/g in salting solution, from $2.8{\times}10^2$ to $1.2{\times}10^4$ CFU/g in dehydrated salted-cabbage. During the manufacture processing of Kim chi, microorganisms were detected in cabbages salted in different concentrations of salt solution at 8%, 10%, 12% and 15% for 5-20 hours. As the results, $3.5{\times}10^5-1.7{\times}10^6$, $3.4{\times}10^5-2.5{\times}10^6$, $5.4{\times}10^5-2.3{\times}10^6$, $4.0{\times}10^5-2.3{\times}10^6$ CFU/g were detected for E. coli in samples at different treatment conditions. $1.9{\times}10^4-4.1{\times}10^4$, $4.1{\times}10^3-2.8{\times}10^4$, $1.5{\times}10^3-7.8{\times}10^3$, $2.2{\times}10^4-6.6{\times}10^4$ CFU/g were detected for S. aureus in samples at different treatment conditions. Salmonella typhimurium was detected in salted cabbage with various salt concentration after salting for 5 hrs, the result ranged from $2.5{\times}10^5$ to $3.8{\times}10^6$ CFU/g, and change of microorganism was the smallest in salted cabbage under the concentration of salting solution at 10% for 15 hours. The cabbage salted in 10% salting solution for 15 hours were washed with water for 2 and 3 times, with chlorine for 3 times, and with acetic acid for 3 times. E. coli was detected in the samples washed with water for 2 and 3 times, washed with chlorine for 3 times. The contamination of S. aureus was $3.0{\times}10^5$ CFU/g in the samples washed with water for 2 times, $5.6{\times}10^3$ CFU/g in the samples washed with acetic acid for 3 times, $3.6{\times}10^5$ CFU/g in the samples washed with water for 3 times and same amount in the samples washed with chlorine for 3 times. According to the results, the contamination of S. aureus was $5.6{\times}10^3$ CFU/g lower in samples washed with chlorine and acetic acid than that in samples washed with water. In case of S. typhimurium, it has been detected in samples washed with water and chlorine, $3.0{\times}10^1$ CFU/g as the lowest concentration among all the samples was measured in the samples washed with acetic acid for 3 times.

Supplementation of Essential Oil Extracted from Citrus Peel to Animal Feeds Decreases Microbial Activity and Aflatoxin Contamination without Disrupting In vitro Ruminal Fermentation

  • Nam, I.S.;Garnsworthy, P.C.;Ahn, Jong Ho
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.11
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    • pp.1617-1622
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    • 2006
  • Long-term storage of feeds or feedstuffs in high temperature and humid conditions can be difficult because of microbial contamination. Essential oil isolated from industrial waste citrus peel could be used as a preservative because it is likely to have anti-bacterial and anti-fungal activity. Our objective was to determine whether different levels (0.028, 0.056 and 0.112 g/kg) of citrus essential oil (CEO) would provide anti-microbial activity and enhance preservation of animal feed without influencing rumen fermentation. At 0.112 g/kg, CEO inhibited growth of Escherichia coli (ATCC 25922) and Salmonela enteritidis (IFO 3313). Growth of E. coli recovered after 24 h of incubation, but S. enteritidis continued to be inhibited for 72 h. Preservation of antibiotic-free diets for swine was assessed by observing anti-aflatoxin activity. Aflatoxin was detected in control feed samples on days 16 (8 ppb) and 21 (8 ppb) and in anti-fungal agent (AA) treated samples on days 16 (2 ppb) and 21 (4 ppb). However, aflatoxin was not detected in feed samples treated with CEO. Treatment with CEO and AA did not influence ruminal pH, dry matter digestibility (DMD) or organic matter digestibility (OMD) over 48 h of incubation in rumen fluid. Acetate and propionate were slightly higher with CEO treatment (p<0.05), but total concentration of volatile fatty acid (VFA) was not significantly affected by treatment. Ammonia-N concentration was slightly higher for the control treatment (p<0.05). This study showed that treating feed with CEO enhances preservation of animal feed without influencing in vitro rumen fermentation.

Evaluation of Antioxidant and Antimicrobial Activities of Ethanol Extracts of Three Kinds of Strawberries

  • Seleshe, Semeneh;Lee, Jong Seok;Lee, Sarah;Lee, Hye Jin;Kim, Ga Ryun;Yeo, Joohong;Kim, Jong Yea;Kang, Suk Nam
    • Preventive Nutrition and Food Science
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    • v.22 no.3
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    • pp.203-210
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    • 2017
  • The antioxidant and antimicrobial activities of three kinds of strawberry ethanol extracts from Robus corchorifolius L. f. (RCL), Rubus parvifolius L. var. parvifolius (RPL), and Duchesnea chrysantha Miq. (DCM) were investigated. The RPL was highest (P<0.05) in phenolic, flavonoid, and anthocyanin contents. 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activities of RPL and DCM extracts were higher than that of RCL (P<0.05). Hydrogen peroxide scavenging activity of RPL was high compared to DCM and RCL (P<0.05). RCL exhibited a significant (P<0.05) potent antioxidant activity in nitric oxide radical inhibition. Inhibition diameter zone (nearest mm) of extracts against the test bacteria ranged from 11.5 in RCL to 12.5 in DCM against Staphylococcus aureus, from 10.5 in RCL to 13.5 in DCM against Streptococcus pneumoniae, from 8.5 in DCM to 10.5 in RCL against Escherichia coli, and the same inhibition of 10 mm in three of the extracts against Klebsiella pneumoniae. However, there was no inhibition against fungi Aspergillus niger and Candida albicans. Three of the extracts had the same minimum inhibitory concentration values of 12.50, 12.50, and $6.25{\mu}g/mL$ against S. aureus, K. pneumoniae, and S. pneumoniae, respectively. On the other hand, MIC values of 12.50, 12.50, and $6.50{\mu}g/mL$ were recorded for RPL, DCM, and RCL against E. coli, respectively. The result of present study revealed that extracts from three kinds of strawberries could be potential candidates as antioxidant and antimicrobial sources for functional food industries.

Antimicrobial Activity of Lentinus edodes Extract (표고버섯(Lentinus edodes)추출물의 항균활성)

  • 김용두;김경제;조덕봉
    • Food Science and Preservation
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    • v.10 no.1
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    • pp.89-93
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    • 2003
  • To develope natural food preservatives, ethanol and water extracts were prepared from the Lentinus edodes and antimicrobial activities were examined against 10 microorganisms which were food borne pathogens and / or food poisoning microorganisms and food-related bacteria and yeasts. Ethanol extract exhibited antimicrobial activities for the microorganisms tested, but not on lactic acid bacteria and yeast Especially, minimum inhibitory concentration(MIC) for Escherichia coli were as low as 0.5 mg/mL. Antimicrobial activity of the ethanol extract was stable by the heating at 121$^{\circ}C$ for 15 min and not affected by pH. The ethanol extract of Lentinus edodes exhibiting high antimicrobial activity. The highest antimicrobial activity adjust bacteria tested was found in the ethylacetate fraction.

The CT values Comparisons for Antibiotic Resistant Bacteria and Resistant Genes by Chlorination (항생제 내성균 및 유전자제거를 위한 염소 CT 값 비교)

  • Oh, Jun-Sik;Kim, Sungpyo
    • Journal of Wetlands Research
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    • v.16 no.2
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    • pp.269-274
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    • 2014
  • The purpose of this study is to compare CT (disinfectant concentration * time) values in removing the antibiotic resistance bacteria, antibiotic resistance gene and transfer of antibiotic resistance genes. Different concentration of chlorine(C) and contact time(T) according to the removal of antibiotic resistance was calculated for each. As a result, for the 90% removal of antibiotic resistant bacteria, around 176~353 mg min/L CT values are needed. For the removal of the antibiotic resistance gene, 195~372 mg min/L CT values are required. For the 90% reduction of antibiotic resistance gene transfer by chlorine disinfection, 187~489 mg min/L CT values are needed. Based on our results, higher CT value was required for removing antibiotic resistant genes rather than antibiotic resistance bacteria.

Determination of Semen Quality and Antibacterial Susceptibility Pattern of Bacteria Isolated from Semen of Iraqi Subjects

  • Faisal, Anwer Jaber;Salman, Hamzah Abdulrahman
    • Microbiology and Biotechnology Letters
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    • v.49 no.4
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    • pp.587-593
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    • 2021
  • Infertility is a key issue affecting mood and behavior in men. Microorganisms are one of the primary etiological agents that may be associated with infertility. The objective of the present study was to identify bacterial causative agents from the semen of infertile subjects and determine the effect of bacterial infection on sperm quality, as well as determine the susceptibility of these bacteria to drugs. Forty semen samples from 30 infertile patients and 10 fertile individuals were collected. The pH, volume, motility, and concentration of semen were analyzed. The samples were processed and identified by biochemical testing using API identification kits. The antibiotic susceptibility pattern was determined using the disc diffusion method. Abnormal sperm quality was observed. The mean age of the individual and their sperm morphology, concentration, progressive motility, pH level, and pus cell content were 31.9 years, 2.7%, 10.4 million/ml, 27.3%, 8.3, and 5.7, respectively. Among the tested samples, oligoasthenozoospermia was found to show the highest occurrence, at 27/30 samples, followed by teratozoospermia, at 25/30 samples, and asthenozoospermia, at 22/30 samples. Of the tested infertile patients' sperm, 19, 6, and 5 isolates were identified as Escherichia coli, Klebsiella pneumonia, and Staphylococcus epidermidis, respectively. The results also revealed multi-drug resistance in the bacteria. Compared to that shown by the other tested antibiotics, amikacin showed higher activity against all isolated bacteria. However, the bacteria exhibited maximum resistance against gentamicin, cefotaxime, levofloxacin, and ampicillin. In conclusion, leukocytospermia and bacterial infections are possibly responsible for sperm abnormalities. Multi-drug resistant bacteria were detected. Gentamicin, cefotaxime, levofloxacin and ampicillin were shown the highest resistance, while amikacin was the most effective antimicrobial agent against the isolated bacteria.

Cellular zinc deficiency inhibits the mineralized nodule formation and downregulates bone-specific gene expression in osteoblastic MC3T3-E1 cells

  • Cho, Young-Eun;Kwun, In-Sook
    • Journal of Nutrition and Health
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    • v.51 no.5
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    • pp.379-385
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    • 2018
  • Purpose: Zinc (Zn) is an essential trace element for bone mineralization and osteoblast function. We examined the effects of Zn deficiency on osteoblast differentiation and mineralization in MC3T3-E1 cells. Methods: Osteoblastic MC3T3-E1 cells were cultured at concentration of 1 to $15{\mu}M$ $ZnCl_2$ (Zn- or Zn+) for 5, 15 and 25 days up to the calcification period. Extracellular matrix mineralization was detected by staining Ca and P deposits using Alizarin Red and von Kossa stain respectively, and alkaline phosphatase (ALP) activity was detected by ALP staining and colorimetric method. Results: Extracellular matrix mineralization was decreased in Zn deficiency over 5, 15, and 25 days. Similarly, staining of ALP activity as the sign of an osteoblast differentiation, was also decreased by Zn deficiency over the same period. Interestingly, the gene expression of bone-related markers (ALP, PTHR; parathyroid hormone receptor, OPN; osteopontin, OC; osteocalcin and COLI; collagen type I), and bone-specific transcription factor Runx2 were downregulated by Zn deficiency for 5 or 15 days, however, this was restored at 25 days. Conclusion: Our data suggests that Zn deficiency inhibits osteoblast differentiation by retarding bone marker gene expression and also inhibits bone mineralization by decreasing Ca/P deposition as well as ALP activity.

Antimicrobial and Antioxidant Properties of Secondary Metabolites from White Rose Flower

  • Joo, Seong-Soo;Kim, Yun-Bae;Lee, Do-Ik
    • The Plant Pathology Journal
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    • v.26 no.1
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    • pp.57-62
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    • 2010
  • Low-molecular-weight secondary metabolites from plants play an important role in reproductive processes and in the defense against environmental stresses or pathogens. In the present study, we isolated various volatiles and phenolic compounds from white Rosa rugosa flowers, and evaluated the pharmaceutical activities of these natural products in addition to their ability to increase survival in response to environmental stress and pathogen invasion. The DPPH and hydroxyl radical-mediated oxidation assay revealed that the white rose flower extract (WRFE) strongly scavenged free radicals in a dose dependent manner. Moreover, WRFE inhibited the growth of E. coli and fatally attacked those cells at higher concentration (>0.5 mg/mL). FITC-conjugated Annexin V stain provided further evidence that WRFE had strong antimicrobial activity, which may have resulted from a cooperative synergism between volatiles (e.g. 1-butanol, dodecyl acrylate and cyclododecane) and phenolic compounds (e.g. gallic acid) retained in WRFE. In conclusion, secondary metabolites from white rose flower hold promise as a potential natural source for antimicrobial and non-chemical based antioxidant agents.