Bacillus Licheniformis Coated Bioparticles for Hydrogen Peroxide Degradation

2012 ◽  
Vol 59 (1) ◽  
Author(s):  
Wei Kheng Teoh ◽  
Zaharah Ibrahim ◽  
Shafinaz Shahir

The potential use of Bacillus licheniformis coated bioparticles for hydrogen peroxide (H2O2) degradation was assessed in this study. Bioparticles were made by mixing zeolite, activated carbon and cement in ratio 20:5:6 for attachment of biofilm. The efficiency of H2O2 degradation was examined in the presence and absence of biofilm (control) on bioparticles. Optimisation of biofilm development (7 and 10 days) and reusability were also investigated for H2O2degradation. Actively growing bacterial suspension (late exponential phase) of B.licheniformis was used in development of pure culture biofilm. The 7–day biofilm coated bioparticles system successfully achieved complete H2O2 degradation within an hour (highest rate = 1.17 % H2O2 degraded per minute) while the control showed no significant H2O2 degradation. After repeated use of biofilm coated bioparticles, the rate of H2O2 degradation declined to 0.654 % H2O2degraded per minute, and second use, the rate of H2O2 degradation was 0.166 % H2O2 degraded per minute. Field Emission Scanning Electron Microscope (FESEM) images of the biofilm coated bioparticles showed the attachment of cells and formation of extracellular polymeric substances (EPS), whereas the control showed no biofilm formed.

2020 ◽  
Vol 14 (1) ◽  
pp. 124-133
Author(s):  
Supajit Sraphet ◽  
Bagher Javadi

Cellulose production of aerobic bacteria with its very unique physiochemical properties attracted many researchers. The biosynthetic of Bacterial Cellulose (BC) was produced by low-cost media recently. BC has been used as biomaterials and food ingredient these days. Moreover, the capacity of BC composite gives the numerous application opportunities in other fields. Bacterial Cellulose (BC) development is differentiated from suspension planktonic culture by their Extracellular Polymeric Substances (EPS), down-regulation of growth rate and up-down the expression of genes. The attachment of microorganisms is highly dependent on their cell membrane structures and growth medium. This is a very complicated phenomenon that optimal conditions defined the specific architecture. This architecture is made of microbial cells and EPS. Cell growth and cell communication mechanisms effect biofilm development and detachment. Understandings of development and architecture mechanisms and control strategies have a great impact on the management of BC formation with beneficial microorganisms. This mini-review paper presents the overview of outstanding findings from isolating and characterizing the diversity of bacteria to BC's future application, from food to biosensor products. The review would help future researchers in the sustainable production of BC, applications advantages and opportunities in food industry, biomaterial and biomedicine.


1996 ◽  
Vol 118 (1) ◽  
pp. 2-8 ◽  
Author(s):  
M. Anheden ◽  
D. Y. Goswami ◽  
G. Svedberg

This paper presents some of the experimental results from a study conducted to demonstrate the potential use of photocatalytic oxidation for decolorization and COD reduction of wastewater from 5–fluorouracil manufacturing. A series of batch experiments, were carried out using diluted solutions of the wastewater with 0.1 percent w/v TiO2. Low pressure mercury lamps were used to simulate the UV part of sunlight. The experiments showed that a complete decolorization and a substantial reduction of COD was achieved within 20 hours with a 20 percent solution. During the reaction period, the pH was noted to decrease considerably, indicating formation of acids. Adding hydrogen peroxide to the solution was found to significantly increase the reaction rates. Adding 2400 ppm of H2O2 gave an 80 percent decrease in color in one hour and a 70-80 percent decrease in COD in 20 hours. The influence of UV-light intensity was also examined. This experiment showed that with a UV-intensity of 15 W/m2, i.e., a cloudy day, the decolorization rate was still considerable, while the COD reduction rate was very low.


1992 ◽  
Vol 47 (5-6) ◽  
pp. 394-399
Author(s):  
Shuji Iwata ◽  
Naoko Nakayama ◽  
Shunji Nakagawara ◽  
Yoshimoto Ohta ◽  
Takaharu Tanaka ◽  
...  

Cell suspension cultures of the liverwort, Marchantia polymorpha L. were found useful to study the influence of peroxidizing herbicides either on the greening process or on the fully green cells. The cells of both physiological stages exhibit a characteristic sensitivity to the herbicides. The sensitivity increased rapidly during the exponential phase of growth, reached a maximum during the late exponential phase, and then decreased in the stationary phase. We investigated the kinetics of accumulation of protoporphyrin IX (PPIX) in Marchantia cells treated with several peroxidizing herbicides at various stages of cell growth, and observed a correlation between accumulation of PPIX and herbicidal damage. The glutathione (GSH) content in the cell was also investigated to examine the role of GSH against herbicide treatment. In the light, GSH levels in the cells treated with AFM rose rapidly reaching a peak after 8 h, and rapidly decreased subsequently. The beginning of PPIX accumulation coincided with the decline of GSH after 8 h of treatment. Obviously, GSH plays a key role in protection against oxidative damage caused by AFM in the early treatment period. In the dark, AFM also induced an accumulation of GSH and PPIX, followed by a decline in GSH and PPIX contents during a 20 h incubation. The decline of PPIX was observed several hours after GSH starts to decrease, remaining at a constant level for the following 40 h, leading to accumulation of an other fluorescent still-unknown pigment.


2017 ◽  
Vol 81 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Woo-Ju Kim ◽  
Ki-Ok Jeong ◽  
Dong-Hyun Kang

ABSTRACT Following sanitation interventions in food processing facilities, sublethally injured bacterial cells can remain on food contact surfaces. We investigated whether injured Salmonella Typhimurium cells can attach onto abiotic surfaces, which is the initial stage for further biofilm development. We utilized heat, UV, hydrogen peroxide, and lactic acid treatments, which are widely utilized by the food industry. Our results showed that heat, UV, and hydrogen peroxide did not effectively change populations of attached Salmonella Typhimurium. Cells treated with hydrogen peroxide had a slightly higher tendency to adhere to abiotic surfaces, although there was no significant difference between the populations of control and hydrogen peroxide–treated cells. However, lactic acid effectively reduced the number of Salmonella Typhimurium cells attached to stainless steel. We also compared physicochemical changes of Salmonella Typhimurium after application of lactic acid and used hydrogen peroxide as a positive control because only lactic acid showed a decreased tendency for attachment and hydrogen peroxide induced slightly higher numbers of attached bacteria cells. Extracellular polymeric substance produced by Salmonella Typhimurium was not detected in any treatment. Significant differences in hydrophobicity were not observed. Surface charges of cell membranes did not show relevant correlation with numbers of attached cells, whereas autoaggregation showed a positive correlation with attachment to stainless steel. Our results highlight that when lactic acid is applied in a food processing facility, it can effectively interfere with adhesion of injured Salmonella Typhimurium cells onto food contact surfaces.


1975 ◽  
Vol 148 (2) ◽  
pp. 253-258 ◽  
Author(s):  
J A Hackett ◽  
P J Brennan

Besides the monomannophosphoinositide previously reported in Corynebacterium aquaticum small amounts of other, apparently more glycosylated, mannophosphoinositides have been identified in stationary phase cells. Moreover, by labelling cells with [32P]Pi, phosphatidylinositol was found, comprising about 1.5% of the stationary-phase phospholipids. 2. Pulse-chase experiments performed on cells in the late exponential phase of growth further suggested the sequence phosphatidylinositol leads to monomannophosphoinositide as the first step in the biosynthesis of the mannophosphoinositides. 3. Di-and tri-mannophosphoinositides are apparently the main mannophosphoinositides present during exponential growth. Monomannophosphoinositide predominates only in late stationary phase; in the earlier stationary phase, phosphatidylinositol comprises 50% of the phosphoinositide lipid, and tetramannophosphoinositide constitutes much of the remainder. 4. The metabolism and functions of the mannophosphoinositides are discussed, particularly in relation to changes in their composition throughout the growth cycle.


2007 ◽  
Vol 73 (19) ◽  
pp. 6233-6240 ◽  
Author(s):  
S. D. Weber ◽  
W. Ludwig ◽  
K.-H. Schleifer ◽  
J. Fried

ABSTRACT Aerobic activated sludge granules are dense, spherical biofilms which can strongly improve purification efficiency and sludge settling in wastewater treatment processes. In this study, the structure and development of different granule types were analyzed. Biofilm samples originated from lab-scale sequencing batch reactors which were operated with malthouse, brewery, and artificial wastewater. Scanning electron microscopy, light microscopy, and confocal laser scanning microscopy together with fluorescence in situ hybridization (FISH) allowed insights into the structure of these biofilms. Microscopic observation revealed that granules consist of bacteria, extracellular polymeric substances (EPS), protozoa and, in some cases, fungi. The biofilm development, starting from an activated sludge floc up to a mature granule, follows three phases. During phase 1, stalked ciliated protozoa of the subclass Peritrichia, e.g., Epistylis spp., settle on activated sludge flocs and build tree-like colonies. The stalks are subsequently colonized by bacteria. During phase 2, the ciliates become completely overgrown by bacteria and die. Thereby, the cellular remnants of ciliates act like a backbone for granule formation. During phase 3, smooth, compact granules are formed which serve as a new substratum for unstalked ciliate swarmers settling on granule surfaces. These mature granules comprise a dense core zone containing bacterial cells and EPS and a loosely structured fringe zone consisting of either ciliates and bacteria or fungi and bacteria. Since granules can grow to a size of up to several millimeters in diameter, we developed and applied a modified FISH protocol for the study of cryosectioned biofilms. This protocol allows the simultaneous detection of bacteria, ciliates, and fungi in and on granules.


1979 ◽  
Vol 182 (1) ◽  
pp. 11-15 ◽  
Author(s):  
D Lloyd ◽  
S Edwards ◽  
B Kristensen ◽  
H Degn

1. Respiration of growing cultures of Acanthamoeba castellanii is inhibited less than 60% by azide (35 mM); the respiration of early-exponential-phase cultures differs from that of late-exponential-phase cultures in being stimulated by up to 120% by low concentrations (less than 1 mM) of this inhibitor. Azide (0.5 mM) plus 1 mM-salicylhydroxamic acid gives 80% inhibition of respiration in early- or late-exponential-phase cultures. 2. Lineweaver-Burk plots of 1/v against 1/[O2] for growing and stationary-phase cultures give values of less than 1 muM for the apparent Km for oxygen. 3. These values are not significantly altered when determined in the presence of 1 mM-salicylhydroxamic acid. 4. Higher values (greater than 7 muM) for apparent Km values for oxygen were obtained in the presence of azide, which gives non-linear Lineweaver-Burk plots. 5. Competitive inhibition of respiration by CO occurs with Ki 2.4 muM. 6. The results are discussed in terms of the presence of three terminal oxidases in this organism, namely two oxidases with high affinities for oxygen (cytochrome c oxidase of the main phosphorylating electron-transport chain and the salicylhydroxamic acid-sensitive oxidase) and a third oxidase with a low affinity for oxygen, sensitive to inhibition by cyanide but not by azide or salicylhydroxamic acid. The relative contributions to oxygen utilization by these oxidases change during the growth of a batch culture.


2020 ◽  
Author(s):  
Maria Papadatou ◽  
Samuel Robson ◽  
Joy Watts ◽  
Sergey Dobretsov ◽  
Maria Salta

<p>Marine biofilms are assemblages of microbial cells irreversibly attached to living or non-living surfaces, embedded in a self-produced matrix of hydrated extracellular polymeric substances (EPS). The phenomenon of biofouling occurs upon the adhesion and accumulation of biofilms, composing the primary colonizers that are capable of EPS production, followed by the sequential growth of secondary colonizers on submerged structures. Biofouling constitutes a significant issue in marine industries (e.g. maritime transportation) and problems related to biofilm fouling include an increase in drag force, modification of surface properties (e.g. metal corrosion) and production of chemical compounds with inhibition effects to other foulers. The use of powerful biocides exhibits a good performance against biofouling, however, often their efficacy is evident to a lesser degree against biofilms. These chemically active compounds have been found to have toxicity effects for marine life and there is a need to discover high-performance environmentally acceptable products.</p> <p>The aim of the present study was to investigate the biofilm community composition and gene-expression on commercial antifouling (AF) coatings employing next-generation sequencing approaches. Natural mixed-species biofilms were examined after a four-month immersion of two commercial AF coatings, including a biocidal (BAF) and a fouling release (FR), and a control non-treated surface in Langstone Harbour UK. Replicated biofilm samples were used for nucleic acid extraction and sequenced targeting the 16S rRNA gene and metatranscriptome.</p> <p>We uncovered distinct biofilm community profiles between the two coatings; the BAF samples were dominated by Bacillariophyceae (diatoms), contrary to the FR and control samples where Oscillatoriophycideae (phylum Cyanobacteria) were prevailing. Alphaproteobacteria and Gammaproteobacteria contributed to a high abundance in all samples. Biofilms on BAF samples exhibited a lower species diversity compared to the FR. Here, we introduce a set of functional genes present across all biofilm-associated communities and highlight the differing gene transcriptional profiles in biocidal treatments. The gene transcriptional analysis uncovered highly enriched genes coding for proteins involved in biofilm regulation and formation. We demonstrated that biocidal-associated biofilms harbor genes that regulate defense mechanisms. Overall, the findings highlight links between differentially expressed protein functions and effects of AF coating type during biofilm development. We anticipate these results to contribute towards further development of antibiofilm strategies and fill gaps related to marine biofilm functions.</p>


1966 ◽  
Vol 101 (3) ◽  
pp. 692-697 ◽  
Author(s):  
R.C. Hughes

1. Particulate fractions prepared from disrupted cells of Bacillus licheniformis N.C.T.C. 6346 catalyse the uptake of radioactivity from UDP-[(14)C]glucuronic acid or UDP-N[(14)C]-acetylglucosamine. Maximal uptake requires the presence of both nucleotides and Mg(2+) ions. The reaction is inhibited markedly by high concentrations of novobiocin and, to a certain extent, by vancomycin and by methicillin. 2. The radioactive product formed is resistant to Pronase and is soluble in 5% (w/v) trichloroacetic acid. It is of high molecular weight, from its behaviour on columns of Sephadex G-50 or G-200, and behaves during paper electrophoresis in n-acetic acid and chromatography on DEAE-cellulose in a manner similar to teichuronic acid. 3. Both teichuronic acid and the synthesized material are resistant to testicular hyaluronidase and to Flavobacterium heparinum heparinase. 4. The specific activity of suspensions of broken cells or of washed particulate fractions is greatest when they are prepared from exponentially growing cells. Fractions obtained from late exponential-phase or stationary-phase cells have very low activity. 5. The galactosamine content of B. licheniformis N.C.T.C. 6346 cell walls increases during the exponential phase and decreases during the stationary phase.


2009 ◽  
Vol 76 (4) ◽  
pp. 1189-1197 ◽  
Author(s):  
Elanna Bester ◽  
Otini Kroukamp ◽  
Gideon M. Wolfaardt ◽  
Leandro Boonzaaier ◽  
Steven N. Liss

ABSTRACT The measurement of carbon dioxide production rates as an indication of metabolic activity was applied to study biofilm development and response of Pseudomonas sp. biofilms to an environmental disturbance in the form of a moving air-liquid interface (i.e., shear). A differential response in biofilm cohesiveness was observed after bubble perturbation, and the biofilm layers were operationally defined as either shear-susceptible or non-shear-susceptible. Confocal laser scanning microscopy and image analysis showed a significant reduction in biofilm thickness and biomass after the removal of the shear-susceptible biofilm layer, as well as notable changes in the roughness coefficient and surface-to-biovolume ratio. These changes were accompanied by a 72% reduction of whole-biofilm CO2 production; however, the non-shear-susceptible region of the biofilm responded rapidly after the removal of the overlying cells and extracellular polymeric substances (EPS) along with the associated changes in nutrient and O2 flux, with CO2 production rates returning to preperturbation levels within 24 h. The adaptable nature and the ability of bacteria to respond to environmental conditions were further demonstrated by the outer shear-susceptible region of the biofilm; the average CO2 production rate of cells from this region increased within 0.25 h from 9.45 ± 5.40 fmol of CO2·cell−1·h−1 to 22.6 ± 7.58 fmol of CO2·cell−1·h−1 when cells were removed from the biofilm and maintained in suspension without an additional nutrient supply. These results also demonstrate the need for sufficient monitoring of biofilm recovery at the solid substratum if mechanical methods are used for biofouling control.


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