Development of a Filtration-Based Bioluminescence Assay for Detection of Microorganisms in Tea Beverages

2016 ◽  
Vol 79 (3) ◽  
pp. 488-492
Author(s):  
YOHEI SHINOZAKI ◽  
TOSHINORI IGARASHI ◽  
YASUHIRO HARADA

ABSTRACT The market for tea drinks as healthy beverages has been steadily expanding, and ready-to-drink beverages in polyethylene terephthalate bottles have been popular. To more rapidly and accurately test tea beverages bottled in polyethylene terephthalate for microbial contamination, a newly developed filtration device and a washing method with a commercial bioluminescence assay were combined to detect low numbers of bacterial spores, fungal conidia, and ascospores. Washing buffers were formulated with nonionic detergents from the Tween series. Commercially available tea beverages were used to evaluate the filtration capacity of the filtration device, the effect of washing buffers, and the performance of the assay. The assay was tested with serially diluted suspensions of colonies of two bacterial strains, spores of three Bacillus strains, conidia of five fungal strains, and ascospores of four fungal strains. The filtration device enabled filtration of a large sample volume (100 to 500 ml), and the washing buffer significantly decreased the background bioluminescence intensity of tea samples when compared with the no-washing method. Low numbers (1 to 10 CFU/100 ml) of the tested strains of bacteria were detected within 8 to 18 h of cultivation, and fungi were detected within 24 to 48 h. Furthermore, a whole bottle (500 ml) of mixed tea was filtered through the filtration device and microbes were detected. This method could be used for quality control of bottled beverages without preincubation.

2019 ◽  
Author(s):  
Matthew Healey ◽  
Muttuswamy Sivakumaran ◽  
Mark Platt

<p>Prion diseases are a group of fatal transmissible neurological conditions caused by the change in conformation of the normal intrinsic cellular prion protein (PrP<sup>C</sup>) in to the highly ordered insoluble amyloid state conformer (PrP<sup>SC</sup>). We present a rapid assay using Aptamers and Resistive Pulse Sensing, RPS, to extract and quantify proteins from complex sample matrices, demonstrate with the quantification of PrP<sup>c</sup>. We functionalise the surface of superparamagnetic beads, SPBs, with a DNA aptamer. First SPB’s termed P-Beads, are used to pre-concentrate the analyte from a large sample volume. The PrP<sup>c</sup> protein is then eluted from the P-Beads before aptamer modified sensing beads, S-Beads, are added. The velocity of the S-Beads through the nanopore reveals the concentration of the PrP<sup>c</sup> protein. The process is done in under an hour and allows the detection of picomol’s of protein. The technique could be easily adopted to the mutated version of the protein and integrated into clinical workflows for the screening of blood donations and transfusions. </p>


2021 ◽  
Author(s):  
Hajira Younas ◽  
Aisha Nazir ◽  
Zakia Latif ◽  
Janice E Thies ◽  
Muhammad Shafiq ◽  
...  

This study encompasses isolation and screening of heavy metal-resistant fungal and bacterial strains from tannery solid waste (TSW). Twelve fungal strains and twenty-five bacterial strains were isolated from TSW. The growth of fungal strains was observed against different heavy metals ranging from 10 mg L -1 to 1050 mg L -1 and the growth of bacteria was observed in metal concentrations ranging from 10 mg L -1 to 1200 mg L -1 . Five multi-metal resistant fungal isolates belonging to the genus Trichoderma and ten bacterial isolates belonging to the genus Bacillus showed good metal resistance and biosorption potential. They were identified through molecular techniques, fungi based on ITS region ribotyping, and bacteria based on 16S rRNA ribotyping. The fungal strains were characterized as T. hamatum (TSWF-06), T. harzianum (TSWF-11), T. lixii (TSWF-02) and T. pseudokoningii (TSWF-03, TSWF-10). The bacterial strains were characterized as Bacillus xiamenensis (TSW-02), B. velezensis (TSW-05), B. piscis (TSW-06), B. safensis (TSW-10), B. subtilis (TSW-14, TSW-15, TSW-17) B. licheniformis (TSW-19), B. cereus (TSW-20) and B. thuringiensis (TSW-22). The fungal strains namely, T. pseudokoningii (TSWF-03) and T. harzianum proved to be two multi-metal resistant strains with good biosorption efficiency. Unlike fungi, bacterial strains showed metal specific resistance. The strains Bacillus xiamenensis , B. subtilis (TSW-14) and B. subtilis (TSW-15) showed good biosorption efficiency against Cr, B. safensis against Cu, B. piscis and B. subtilis (TSW-17) against Pb and B. licheniformis and B. thuringiensis against Zn. The autochthonous fungal and bacterial strains can therefore be employed to clean metal contaminated environments.


Author(s):  
P Danish ◽  
Q Ali ◽  
MM Hafeez ◽  
A Malik

Aloe vera is a well-known medicinal plant used in many therapeutic purposes. Naturally it is composed of many useful compounds that have ability to use for treatment of many diseases. The active compounds reported in this plant are saponins, sugar, enzymes, vitamins, aloesin, aloeemodin, aloin, acemannan aloemannan, aloeride, methylchromones, flavonoids, naftoquinones, sterols, minerals, anthraquinones, amino acids, lignin and salicylic acid and other different compounds including fat-soluble and water-soluble vitamins, enzymes, minerals, simple/complex sugars, organic acid and phenolic compounds. In this study aloe vera is used for antibacterial and antifulgal activity against different strains of bacteria and pathogenic fungal strains. Ethanol extract of Aloe vera leaves and roots is applied on these bacterial and fungal strains in different concentrations (15, 20, 25, 30µl). Bacillus cereus, Bacillus subtitis, Bacillus megaterium, Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, and some other bacterial strains are used for this study. Escherichia coli and Agrobacterium tumefacins shows zone of inhibition around 18mm which consider as good result. Bacillus subtitis and Bacillus megaterium also shows good result around 16mm. Proteus mirabilis and Pseudomonas aeruginosa shows minimum zone of inhibition which is around 11mm. among all used fungal strains (fuserium oxysporum, Candida albicans, Aspergillus fumigatus, Aspergillus niger) fuserium oxysporum and Aspergillus niger shows excellent results around 19mm both against root extract and leaves extract.


2020 ◽  
Author(s):  
Mariana Ferdes ◽  
Rodica Roxana Constantinescu

The chrome shavings waste obtained as a result of the leather finishing process accumulates in a large volume in tanneries and represent a major problem for the environment. This waste are particularly resistant to attack of microorganisms, due to the significant concentration of chromium and are thus difficult to degrade. In this study, chrome shavings were analyzed microbiologically by determining the total number of germs and the number of yeasts and molds on specific culture media. Several bacterial and fungal strains were isolated from the cultures in Petri dishes, after the growth of the colonies. These strains were characterized in terms of the production of proteolytic enzymes, by a method of screening on the media with casein, which allows the determination of proteolytic indices of microorganisms. As a result of the tests performed, five bacterial strains probably belonging to the genus Bacillus and two fungal strains from the genera Penicillium and Cladosporium were selected.


Author(s):  
Nidal Jaradat ◽  
Saad Al-Lahham

Abstract Background Many recent studies have shown that medicinal plants, which have been used worldwide through the past history in the folkloric medicine, harbor a significant number of novel metabolic compounds with potent pharmacological properties. In several countries, the aerial parts of the Scolymus angiospermus plant have been used as a food supply and as a folkloric medicinal plant. The current study aimed is to investigate the antimicrobial, antilipase, antioxidant activities and phytochemical profile of methanolic, hexane, aqueous and ethyl acetate fractions obtained from the aerial parts of S. angiospermus. Methods Phytochemical assessments were based on standard analytical methods. The obtained fractions were evaluated for their antioxidant capacity and their antilipase activity using 2,2-diphenyl-1-picrylhydrazyl and porcine pancreatic lipase inhibitory tests, respectively. Antimicrobial activity of the obtained fractions was evaluated using broth microdilution assay against several American Type Culture Collection bacterial and fungal strains and Methicillin-Resistant Staphylococcus aureus clinical isolate. Results Our data showed that of all obtained fractions used in the above-mentioned assays, both of methanolic and aqueous fractions, had the highest content of flavonoids (24.93 ± 2.11 and 12.21 ± 2.11 mg QUE/g, respectively) and phenolic compounds (96.28 ± 2.87 and 91.25 ± 2.63 mg of GAEq/g, respectively) as well as the best levels of both antioxidant (half maximal inhibitory concentration (IC50) 13.67 ± 1.44 and 14.69 ± 1.97 µg/ml, respectively) and antilipase (IC50 134.89 ± 1.65 and 269.15 ± 2.33 µg/ml, respectively) activities. In addition, these fractions exhibited various levels of both antibacterial and antifungal activities. Hydrophilic fractions were more potent against the investigated bacterial strains, while hydrophobic fractions were more potent against the investigated fungal strains. Conclusions The hydrophilic fractions derived from S. angiospermus have shown the best antioxidant and antilipase effects. This is may be due to the high contents of phenols and/or flavonoids. However, further investigations are essential to isolate and identify the antioxidant, antilipase and antimicrobial compounds. Our data provide significant evidence that S. angiospermus can be very useful in the prevention and treatment of various infectious and non-infectious chronic diseases and as natural food preservatives.


2012 ◽  
Vol 2 (5) ◽  
pp. 217-226
Author(s):  
E. O. Omwenga ◽  
P. O. Okemo ◽  
P. K. Mbugua

The antimicrobial effect of some selected Samburu medicinal plants was evaluated on bacterial strains like Staphylococcus aureus ‐ ATCC 20591, Bacillus subtillis ‐ Local isolate, Salmonella typhi‐ATCC 2202, Escherichia coli‐STD. 25922 and Pseudomonas aeroginosa ‐ ATCC 25852 and fungal strains like Candida albicans ATCC EK138, Aspergillus niger ATCC 16404, Aspergillusflavus‐Local isolate, Fusarium lateritium‐Local isolate, and Penicillium spp.‐ local isolate. Methanol was used as solvent for the extraction from the selected medicinal plants used by the Samburu community. The in vitro antimicrobial activity was performed by agar disc diffusion and micro‐dilution technique. The most susceptible Gram‐positive bacterium was S. aureus, while the most susceptible Gram‐negative bacterium was P. aeroginosa. The extracts of Gomphocarpus fruticosus (L) W.T. Aiton showed less activity against the bacterial strains investigated. The most active antibacterial plants were Euphorbia scarlatica S. Carter, and Euclea divinoram Hiern. Incidentally most of the extracts were inactive against the fungal strains with only a few proving to be slightly active against the C. albicans i.e. Loranthus acaciae Zucc., Kedrostis pseudogijef (Gilg) C. Jeffrey, Euclea divinoram Hiern. and Croton macrostachyus (A. Rich). Benths. The significant antimicrobial activity of active extracts was compared with the standard antimicrobials, cefrodoxima, amoxicillin and fluconazole. The MICs of the most active plants ranged from 18.75mg/ml to 37.50mg/ml. The MBCs ranged between 18.75mg/ml to75mg/ml. These results were significant at P< 0.01. The findings show that most of the medicinal plants used by the Samburu community have some significant activity on the bacterial but not fungal pathogens known to cause diarrhoea.


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