scholarly journals Cell Adsorption and Selective Desorption for Separation of Microbial Cells by Using Chitosan-Immobilized Silica

2005 ◽  
Vol 71 (12) ◽  
pp. 8895-8902 ◽  
Author(s):  
Munehiro Kubota ◽  
Masayoshi Matsui ◽  
Hiroyuki Chiku ◽  
Nobuyuki Kasashima ◽  
Manabu Shimojoh ◽  
...  

ABSTRACT Cell adsorption and selective desorption for separation of microbial cells were conducted by using chitosan-immobilized silica (CIS). When chitosan was immobilized onto silica surfaces with glutaraldehyde, bacterial cells adsorbed well and retained viability. Testing of the adsorption and desorption ability of CIS using various microbes such as Escherichia coli, Aeromonas hydrophila, Pseudomonas aeruginosa, Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Lactobacillus casei, Streptococcus mutans, Streptococcus sobrinus, Streptococcus salivarius, Saccharomyces cerevisiae, Saccharomyces ludwigii, and Schizosaccharomyces pombe revealed that most microbes could be adsorbed and selectively desorbed under different conditions. In particular, recovery was improved when l-cysteine was added. A mixture of two bacterial strains adsorbed onto CIS could also be successfully separated by use of specific solutions for each strain. Most of the desorbed cells were alive. Thus, quantitative and selective fractionation of cells is readily achievable by employing chitosan, a known antibacterial material.

2010 ◽  
Vol 28 (No. 5) ◽  
pp. 392-406 ◽  
Author(s):  
D. Żyżelewicz ◽  
E. Nebesny ◽  
I. Motyl ◽  
Z. Libudzisz

Manufacturing of novel foodstuffs supplemented with live probiotic bacteria has recently been intensively investigated. The supplementation of confectionery with probiotics is troublesome since some unit technological processes are conducted at high temperatures and the products are usually stored at ambient temperature. Our group has developed a method of the production of milk chocolate, sweetened with either sucrose or isomalt and aspartame, containing 32, 36, or 40 g/100 g fat, and supplemented with live cells of probiotic bacterial strains: Lactobacillus casei and paracasei. This new milk chocolate displayed the same sensory properties as the reference, probiotic-free chocolate. The number of live bacterial cells was maintained at the functional level of 10<sup>6</sup> &divide; 10<sup>8</sup> cfu/g after keeping for 12 months irrespective of the temperature. The highest number of live probiotic bacteria survived in the chocolate kept at 4&deg;C. Thus the product can be regarded as functional food.


Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 293 ◽  
Author(s):  
Aleksandra Bocian ◽  
Ewa Ciszkowicz ◽  
Konrad K. Hus ◽  
Justyna Buczkowicz ◽  
Katarzyna Lecka-Szlachta ◽  
...  

One of the key problems of modern infectious disease medicine is the growing number of drug-resistant and multi-drug-resistant bacterial strains. For this reason, many studies are devoted to the search for highly active antimicrobial substances that could be used in therapy against bacterial infections. As it turns out, snake venoms are a rich source of proteins that exert a strong antibacterial effect, and therefore they have become an interesting research material. We analyzed Naja ashei venom for such antibacterial properties, and we found that a specific composition of proteins can act to eliminate individual bacterial cells, as well as the entire biofilm of Staphylococcus epidermidis. In general, we used ion exchange chromatography (IEX) to obtain 10 protein fractions with different levels of complexity, which were then tested against certified and clinical strains of S. epidermidis. One of the fractions (F2) showed exceptional antimicrobial effects both alone and in combination with antibiotics. The protein composition of the obtained fractions was determined using mass spectrometry techniques, indicating a high proportion of phospholipases A2, three-finger toxins, and L-amino acids oxidases in F2 fraction, which are most likely responsible for the unique properties of this fraction. Moreover, we were able to identify a new group of low abundant proteins containing the Ig-like domain that have not been previously described in snake venoms.


Foods ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 166
Author(s):  
Aswathi Soni ◽  
Jonghyun Choi ◽  
Gale Brightwell

Plasma-activated water (PAW) is generated by treating water with cold atmospheric plasma (CAP) using controllable parameters, such as plasma-forming voltage, carrier gas, temperature, pulses, or frequency as required. PAW is reported to have lower pH, higher conductivity, and higher oxygen reduction potential when compared with untreated water due to the presence of reactive species. PAW has received significant attention from researchers over the last decade due to its non-thermal and non-toxic mode of action especially for bacterial inactivation. The objective of the current review is to develop a summary of the effect of PAW on bacterial strains in foods as well as model systems such as buffers, with a specific focus on fruit and vegetables. The review elaborated the properties of PAW, the effect of various treatment parameters on its efficiency in bacterial inactivation along with its usage as a standalone technology as well as a hurdle approach with mild thermal treatments. A section highlighting different models that can be employed to generate PAW alongside a direct comparison of the PAW characteristics on the inactivation potential and the existing research gaps are also included. The mechanism of action of PAW on the bacterial cells and any reported effects on the sensory qualities and shelf life of food has been evaluated. Based on the literature, it can be concluded that PAW offers a significant potential as a non-chemical and non-thermal intervention for bacterial inactivation, especially on food. However, the applicability and usage of PAW depend on the effect of environmental and bacterial strain-based conditions and cost-effectiveness.


2021 ◽  
Vol 9 (5) ◽  
pp. 974
Author(s):  
Marc-Kevin Zinn ◽  
Marco Singer ◽  
Dirk Bockmühl

Although malodour formation on textiles and in washing machines has been reported to be a very relevant problem in domestic laundry, the processes leading to bad odours have not been studied intensively. In particular, the smell often described as “wet-and-dirty-dustcloth-like malodour” had not been reproduced previously. We developed a lab model based on a bacterial mixture of Micrococcus luteus, Staphylococcus hominis, and Corynebacterium jeikeium, which can produce this odour type and which might allow the detailed investigation of this problem and the development of counteractions. The model uses bacterial strains that have been isolated from malodourous textiles. We could also show that the three volatile compounds dimethyl disulfide, dimethyl trisulfide, and indole contribute considerably to the “wet-fabric-like” malodour. These substances were not only found to be formed in the malodour model but have already been identified in the literature as relevant malodourous substances.


2012 ◽  
Vol 40 (6) ◽  
pp. 1330-1335 ◽  
Author(s):  
Kamrul Hasan ◽  
Sunil A. Patil ◽  
Dónal Leech ◽  
Cecilia Hägerhäll ◽  
Lo Gorton

Electrochemical communication between micro-organisms and electrodes is the integral and fundamental part of BESs (bioelectrochemical systems). The immobilization of bacterial cells on the electrode and ensuring efficient electron transfer to the electrode via a mediator are decisive features of mediated electrochemical biosensors. Notably, mediator-based systems are essential to extract electrons from the non-exoelectrogens, a major group of microbes in Nature. The advantage of using polymeric mediators over diffusible mediators led to the design of osmium redox polymers. Their successful use in enzyme-based biosensors and BFCs (biofuel cells) paved the way for exploring their use in microbial BESs. The present mini-review focuses on osmium-bound redox systems used to date in microbial BESs and their role in shuttling electrons from viable microbial cells to electrodes.


Author(s):  
R. Cabrera-Contreras ◽  
R. Morelos-Ramírez ◽  
J. P. Quiróz-Ríos ◽  
D. Muñoz-Quiróz

Essential oils (EOs) are commonly used in food industry, due that they possess antioxidative and antimicrobial properties. There are few essential oils that have been used in medicine, due to its potent antibacterial activity against intrahospital pathogens. OEO has experimentally shown potent antibacterial effect on nosocomial Gram-positive bacteria, therefore it can be very useful in hospital environments, where there are many bacterial pathogens, which are the etiological agents of nosocomial infections and most of them are resistant to several antibiotics. Objective: The aim of this study was to determine antimicrobial effect of OEO on most frequent bacterial intrahospital pathogens: MRSA, MRSE comparatively to selected ATCC bacterial reference strains. Methods: This experimental study investigates the antibacterial action of oregano (Origanum vulgare) essential oil (OvEO) on two human pathogens: Staphylococcus aureus (SA) and Staphylococcus epidermidis (SE) Here, we used OEO against one of the most prominent antibiotic-resistant bacterial strains: methicillin-resistant SA (MRSAmecA+ = Meticillin Resistant SA and mecA- = Meticillin Resistance SA ), methicillin-resistant SE (MRSEmecA+ = Meticillin Resistance Staphylococcus epidermidis mecA+) and reference strains: S. aureus ATCC 700699, S. epidermidis ATCC 359845 and E. coli ATCC 25922. Bactericidal effects of the OEO on these bacteria were mainly evaluated using undiluted and four serial dilutions in coconut oil (CCO) l: 1:10, 1:100, 1:200, 1:400. Results: OEO, undiluted and 4 serial dilutions showed potent antibacterial activity against all strains tested. In conclusion, this OEO could be used as an alternative in medicine. The ability of OEO to inhibit and kill clinical Multi-Drug-Resistant (MDR): MRSA and MRSE strains, highlights it´s potential for use in the management of drug-resistant MDR infections in hospitals wards.


2010 ◽  
Vol 4 (1) ◽  
pp. 72-81
Author(s):  
Abdul Wahed Baker ◽  
Zaid A. A. ◽  
Amer A. A.

The study included manufacturing of fermented dairy products by using full cream milk of four kinds of mammalian: (Buffalos, Cows, Sheep's and Goats); with the use of Lactobacillus casei as a starter for the production of fermented dairy products which had the ability to lower cholesterol percentage in the above mentioned products by (71.4, 70, 74.8 and 67.7)% respectively. The viability of Lb. casei had not been affected significantly during storage shelf life of 21days " The product shelf life " , keeping their therapeutic properties unaltered with high viable number of bacteria at time of consumption. The viable counts of the bacteria after storage period for manufactured products were (1.06× 109, 8.1× 108, 7.5× 108and 8× 108) CFU/ml respectively. These numbers represent a decrease equal to one logarithmic cycle for each of manufactured products of Cows, Sheep's and Goats milk, and the decrease of bacteria's viability of manufactured products of Buffalos milk was less than one logarithmic cycle. Results of statistical analysis showed that there was highly significant differences (P<0.05) in the viable bacterial cells counts between manufactured products. By sensory comparison of the manufactured fermented products together, the results shows that the manufactured products from Buffalos milk was the best then the manufactured products of Cows milk then Sheep's milk then goats milk


2021 ◽  
Vol 32 (1) ◽  
pp. 33-39
Author(s):  
Atef Chouikh ◽  
Fatma Alia

Abstract This study aimed to evaluate the phytochemical properties, antibacterial and anti free-radical activities of Retama raetam extracts which is growing in the South-East of the Algeria Desert. The chemical screening showed the presence of many secondary metabolites such as tannins catechin, sterols and terpenes, and the absence of gallic tannins compounds. The obtained results demonstrated that the methanolic extract has shown moderate total phenolic and flavonoids contents (31.59 ± 2.82 mg AG E/g extract and 14.35 ±1.02 mg Qu E/g extract respectively). In the free radical DPPH test, the values of IC50 were converging in all extracts of R. raetam. The antibacterial activity of extracts has been tested against ten bacterial strains, were registered as the best inhibition zones with Vibrio cholera, Micrococcus luteus and Serratia marcescen. Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923 strains showed high resistance against most of all concentrations of extracts, and we noted the Gram-negative bacteria strains are the most sensitive to the different extracts of the plant. The qualitative analysis of extracts by using HPLC showed the contrast in presence of the phenolic compounds, such as in ethyl acetate extract registered absence of chlorogenic acid, also the absence of caffeic acid in 1-butanol extract. These results confirmed of the phenolic extracts of this plant are a source natural alternative to antibiotics and antioxidants.


2015 ◽  
Vol 16 (4) ◽  
pp. 291-298 ◽  
Author(s):  
Roghayeh Ghorbanzadeh ◽  
Babak Pourakbari

ABSTRACT Aim Polymethyl-methacrylate (PMMA) is commonly used primarily for baseplates of orthodontic appliances (BOA). The activities of cariogenic bacteria in biofilm on these surfaces may contribute to dental caries, gingival inflammation and periodontal disease. The PMMA incorporated with nanoparticles of silver (NanoAg-I-PMMA) and NanoAg in situ in PMMA (NanoAg-IS-PMMA) have been shown to control the growth of cariogenic bacteria, but clinical trial of anti-cariogenic application of these novel materials in orthodontics has not been evaluated. The main aim of the study is to compare the clinical effectiveness of using NanoAg-IS-PMMA and NanoAg-I-PMMA for construction of new BOA in inhibiting the planktonic growth and biofilm formation of the cariogenic bacteria. Materials and methods Twenty four patients with a median age of 12.6 years (7-15) harboring Streptococcus mutans, Streptococcus sobrinus and Lactobacillus acidophilus as well as Lactobacillus casei participated in the randomized, doubleblind, cross-over study. The experimental BOA, NanoAg-ISBOA and NanoAg-I-BOA, contained 0.5% w/w NanoAg while the control BOA was standard PMMA. Antibacterial effect of NanoAg-IS-BOA and NanoAg-I-BOA was assessed against test cariogenic bacteria by planktonic and biofilm bacterial cells growth inhibition. Results The average levels of test cariogenic bacteria in saliva decreased about 2 to 70 fold (30.9-98.4%) compared to baseline depending on the microorganism type and test BOA. Biofilm inhibition analysis demonstrated that NanoAg-I-BOA and NanoAg-IS-BOA inhibited the biofilm of all test bacteria by 20.1 to 79.9% compared to BOA. NanoAg-IS-BOA had a strong anti-biofilm effect against S. mutans, S. sobrinus and L. casei. However, NanoAg-I-BOA showed only slight antibiofilm effects on test bacteria. Most notably, at all period of the clinical trial, NanoAg-IS-BOA showed a higher antibacterial activity than NanoAg-I-BOA. Conclusion Based on the novel data that presented here, the NanoAg-IS-BOA had strong antimicrobial activity in the planktonic phase and subsequent biofilm formation of the cariogenic bacteria. Clinical significance Wearing of NanoAg-IS-BOA has the potential to minimize dental plaque formation and caries during orthodontic treatment. How to cite this article Ghorbanzadeh R, Pourakbari B, Bahador A. Effects of Baseplates of Orthodontic Appliances with in situ generated Silver Nanoparticles on Cariogenic Bacteria: A Randomized, Double-blind Cross-over Clinical Trial. J Contemp Dent Pract 2015;16(4):291-298.


Author(s):  
KAMNI RAJPUT ◽  
RAMESH CHANDRA DUBEY

Objective: In vitro antioxidant activity, in vivo antidiabetic property and intestinal attachment by two potential probiotic bacterial strains, namely, Enterococcus faecium and Enterococcus hirae were studied using albino rats. Methods: Antioxidant the activity was assessed using 2,2-Diphenyl-1-picrylhydrazyl radicals scavenging assay. Alloxan was administered intraperitoneally to induce diabetic conditions in experimental rats. Animals were treated with oral administration of Enterococcus spp., such as E. faecium, and E. hirae isolated from goat and sheep milk. The control animal group received normal saline for the same days. Glibenclamide drug was used as a positive control against probiotic bacterial cells. Results: However, administration of probiotic bacterial strains E. faecium and E. hirae, in albino rats significantly (p<0.05) at varying doses lowered blood glucose levels in diabetic rats as compared to the diabetic control group. Both the species of Enterococcus increased the bodyweight of experimental rats. However, E. faecium was the best antidiabetic strain having the antioxidant activities also in comparison to E. hirae. The attachment of probiotic bacterial cells E. faecium on the rat’s intestine wall against pathogens was examined. Furthermore, E. faecium showed its aggregation with pathogens by attachment of the intestines of albino rats. This showed that both the bacterial strains exhibited in vivo antidiabetic effect. Conclusion: The results of this study showed that probiotic bacteria possess antioxidant, antidiabetic activities, and attachment of intestine.


Sign in / Sign up

Export Citation Format

Share Document