Antimicrobial activities of high molecular weight water-soluble chitosans against selected gram-negative and gram-positive foodborne pathogens

The Streptococcus mutans GS5 glucosyltransferase activities (both water-soluble and -insoluble glucan-synthesizing fractions) were inhibited by purified lipoteichoic acid. In vitro sucrose-dependent colonization of smooth surfaces by strain GS5 was also markedly reduced in the presence of the amphipathic molecules. The inhibition of soluble glucan synthesis by lipoteichoic acid appeared to be competitive with respect to both sucrose and primer dextran T10. These inhibitory effects were dependent on the presence of the fatty acid components of lipoteichoic acid since deacylated lipoteichoic acids did not inhibit glucosyltransferase activity. However, the deacylated molecules did interact with the enzymes since deacylated lipoteichoic acid partially protected the enzyme activity against heat inactivation and also induced the formation of high-molecular-weight enzyme complexes from the soluble glucan-synthesizing fraction. The presence of teichoic acid in high-molecular-weight aggregates of glucosyltransferase isolated from the culture fluids of strain GS5 was suggested by the detection of polyglycerophosphate in these fractions. In addition to strain GS5, two other organisms containing polyglycerophosphate teichoic acids, Lactobacillus casei and Lactobacillus fermentum , were demonstrated to bind glucosyltransferase activity. These results are discussed relative to the potential role of teichoic acid-glucosyltransferase interactions in enzyme binding to the cell surface of S. mutans and the formation of high-molecular-weight enzyme aggregates in the culture fluids of the organism.

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Seasonal variation of high-molecular-weight compounds in the water-soluble fraction of organic urban aerosols

Journal of Geophysical Research Atmospheres ◽

10.1029/2005jd005910 ◽

2005 ◽

Vol 110 (D23) ◽

Cited By ~ 56

Author(s):

V. Samburova ◽

S. Szidat ◽

C. Hueglin ◽

R. Fisseha ◽

U. Baltensperger ◽

...

Keyword(s):

Molecular Weight ◽

Seasonal Variation ◽

High Molecular Weight ◽

Soluble Fraction ◽

Water Soluble ◽

Urban Aerosols ◽

Water Soluble Fraction

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ANTIMICROBIAL ACTIVITY OF A MONOALKYL BENZENE SULPHONATE COMPLEX

Canadian Journal of Microbiology ◽

10.1139/m62-083 ◽

1962 ◽

Vol 8 (5) ◽

pp. 621-628 ◽

Cited By ~ 1

Author(s):

W. A. Taber ◽

B. B. Wiley

Keyword(s):

Active Component ◽

Fusarium Species ◽

Antimicrobial Activities ◽

Gram Negative Bacteria ◽

Fusarium Spp ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Household Detergent ◽

Fungi Imperfecti

The antimicrobial activities of a branched, monoalkyl benzene sulphonate complex (ABS), the active component of a commercial liquid household detergent, and of the detergent have been investigated. Cultures of dermatophytes, Candida albicans, saprophytic phycomycetes, ascomycetes, fungi imperfecti, Gram-positive and Gram-negative bacteria were tested. Only the Fusarium species and the Gram-negative bacteria were not inhibited by a concentration of 0.1 ml of the detergent/50 ml medium. Microgram quantities of ABS inhibited the Gram-positive bacteria and the fungi except Fusarium spp. ABS was lethal in microgram quantities, the effect being detectable within 30 minutes. Inhibition of exogenous respiration of glucose by C. albicans began upon contact and was complete within 50 minutes. A linear and biodegradable ABS was more active than the branched form against C. albicans.

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In Vitro Antimicrobial Activities of β-Lactams, Aminoglycosides, Quinolones, Glycopeptides and Trimethoprim-Sulfamethoxazole Against Gram-Negative and Gram-Positive Bacteria Isolated from Patients with Intraabdominal Infections

Advances in Abdominal Surgery 2002 ◽

10.1007/978-94-017-0637-7_1 ◽

2002 ◽

pp. 3-12

Author(s):

Giovanna Branca ◽

Teresa Spanu ◽

Fiammetta Leone ◽

Patrizia Mazzella ◽

Giovanni Fadda

Keyword(s):

Antimicrobial Activities ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Intraabdominal Infections

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Catalytic Degradation of Chitosan by Supported Heteropoly Acids in Heterogeneous Systems

Catalysts ◽

10.3390/catal10091078 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1078

Author(s):

Hang Zhang ◽

Zhipeng Ma ◽

Yunpeng Min ◽

Huiru Wang ◽

Ru Zhang ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Molecular Weight ◽

Catalytic Activity ◽

Activated Carbon ◽

Reaction Time ◽

High Molecular Weight ◽

Reaction Temperature ◽

Water Soluble ◽

High Catalytic Activity ◽

High Molecular Weight Chitosan

Several kinds of composite materials with phosphotungstic acid (PTA) as the catalyst were prepared with activated carbon as support, and their structures were characterized. According to the Box–Behnken central combination principle, the mathematical model of the heterogeneous system is established. Based on the single-factor experiments, the reaction temperature, the reaction time, the amount of hydrogen peroxide and the loading capacity of PTA were selected as the influencing factors to study the catalyzed oxidation of hydrogen peroxide and degradation of high molecular weight chitosan. The results of IR showed that the catalyst had a Keggin structure. The results of the mercury intrusion test showed that the pore structure of the supported PTA catalyst did not change significantly, and with the increase of PTA loading, the porosity and pore volume decreased regularly, which indicated that PTA molecules had been absorbed and filled into the pore of activated carbon. The results of Response Surface Design (RSD) showed that the optimum reaction conditions of supported PTA catalysts for oxidative degradation of high molecular weight chitosan by hydrogen peroxide were as follows: reaction temperature was 70 ℃, reaction time was 3.0 h, the ratio of hydrogen peroxide to chitosan was 2.4 and the catalyst loading was 30%. Under these conditions, the yield and molecular weight of water-soluble chitosan were 62.8% and 1290 Da, respectively. The supported PTA catalyst maintained high catalytic activity after three reuses, which indicated that the supported PTA catalyst had excellent catalytic activity and stable performance compared with the PTA catalyst.

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Degradation of Polycyclic Aromatic Hydrocarbons by Moderately Halophilic Bacteria from Luzon Salt Beds

Journal of Health and Pollution ◽

10.5696/2156-9614-8.19.180915 ◽

2018 ◽

Vol 8 (19) ◽

Cited By ~ 1

Author(s):

Carolyn L. Nanca ◽

Kimberly D. Neri ◽

Anna Christina R. Ngo ◽

Reuel M. Bennett ◽

Gina R. Dedeles

Keyword(s):

Molecular Weight ◽

Polycyclic Aromatic Hydrocarbons ◽

Aromatic Hydrocarbons ◽

Halophilic Bacteria ◽

Sole Source ◽

The Philippines ◽

Liquid Fuels ◽

Gram Positive ◽

Gram Negative ◽

Polycyclic Aromatic

Background. Polycyclic aromatic hydrocarbons (PAHs) are common environmental contaminants which are highly toxic due to their carcinogenic and mutagenic effects. They are released into the environment by incomplete combustion of solid and liquid fuels, accidental spillage of oils and seepage from industrial activities. One of the promising processes mitigating PAHs is through biodegradation. However, conventional microbiological treatment processes do not function well at high salt concentrations. Hence, utilization of halophilic bacteria should be considered. Objectives. This study aimed to assess the ability of halophilic bacteria isolated from local salt beds in Pangasinan and Cavite, the Philippines, to degrade PAHs pyrene, fluorene and fluoranthene. Methods. Polycyclic aromatic hydrocarbon-tolerant halophilic bacteria collected from two sampling sites were phenotypically characterized, molecularly identified and tested to determine their potential to degrade the PAHs pyrene, fluorene and fluoranthene at a hypersaline condition. Best PAH degraders were then assayed to identify the optimal degradation using such parameters as pH, temperature and PAH concentration. Testing for enzyme degradation was also done to determine their baseline information. Extraction and analysis of degraded PAHs were performed using centrifugation and UV-vis spectrophotometry. Results. Twelve isolates from both collection sites tolerated and grew in culture with selected PAHs. These were identified into four genera (Halobacillus, Halomonas, Chromohalobacter, and Pontibacillus). Selected best isolates in a series of biodegradation assays with the above-mentioned parameters were Halobacillus B (Collection of Microbial Strains (CMS) 1802) (=trueperi) (Gram-positive) for pyrene and fluoranthene, and Halomonas A (CMS 1901) (Gram-negative) for fluorene. Degrader biomass and PAH degradation were invariably negatively correlated. Qualitative tests with and without peptone as a nitrogen source implied enzymatic degradation. Discussion. Polycyclic aromatic hydrocarbons utilized by these halophilic bacteria served as a sole source of carbon and energy. Implications of biodegradation of the two best isolates show that high molecular weight (HMW) (4-ring) pyrene tends to be degraded better by Gram-positive bacteria and low molecular weight (3-ring) fluorene by Gram-negative degraders. Conclusions. Halophilic bacteria constitute an untapped natural resource for biotechnology in the Philippines. The present study demonstrated their potential use in bioremediation of recalcitrant hydrocarbons in the environment. Competing Interests. The authors declare no competing financial interests.

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Antimicrobial Activity of Lignin and Lignin-Derived Cellulose and Chitosan Composites Against Selected Pathogenic and Spoilage Microorganisms

Polymers ◽

10.3390/polym11040670 ◽

2019 ◽

Vol 11 (4) ◽

pp. 670 ◽

Cited By ~ 17

Author(s):

Alzagameem ◽

Klein ◽

Bergs ◽

Do ◽

Korte ◽

...

Keyword(s):

Antimicrobial Activity ◽

Low Temperatures ◽

Food Packaging ◽

Antimicrobial Activities ◽

Gram Negative Bacteria ◽

Scavenging Activity ◽

Gram Positive ◽

Gram Negative ◽

Spoilage Bacteria ◽

Chitosan Films

The antiradical and antimicrobial activity of lignin and lignin-based films are both of great interest for applications such as food packaging additives. The polyphenolic structure of lignin in addition to the presence of O-containing functional groups is potentially responsible for these activities. This study used DPPH assays to discuss the antiradical activity of HPMC/lignin and HPMC/lignin/chitosan films. The scavenging activity (SA) of both binary (HPMC/lignin) and ternary (HPMC/lignin/chitosan) systems was affected by the percentage of the added lignin: the 5% addition showed the highest activity and the 30% addition had the lowest. Both scavenging activity and antimicrobial activity are dependent on the biomass source showing the following trend: organosolv of softwood > kraft of softwood > organosolv of grass. Testing the antimicrobial activities of lignins and lignin-containing films showed high antimicrobial activities against Gram-positive and Gram-negative bacteria at 35 °C and at low temperatures (0–7 °C). Purification of kraft lignin has a negative effect on the antimicrobial activity while storage has positive effect. The lignin release in the produced films affected the activity positively and the chitosan addition enhances the activity even more for both Gram-positive and Gram-negative bacteria. Testing the films against spoilage bacteria that grow at low temperatures revealed the activity of the 30% addition on HPMC/L1 film against both B. thermosphacta and P. fluorescens while L5 was active only against B. thermosphacta. In HPMC/lignin/chitosan films, the 5% addition exhibited activity against both B. thermosphacta and P. fluorescens.

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