scholarly journals Biodegradation of Hexavalent Chromium from Paint Industry Effluent by Indigenous Bacteria

Hexavalent chromium (Cr-VI) is toxic, mutagenic and carcinogenic chemical, whereas its reduced trivalent form (Cr-III) is much less toxic. Cr-VI is widely used in paint industry, tannery industry, and so on. In the present study an attempt was made to isolate naturally occurring bacteria from paint industry effluent possessing high potentiality to reduce Cr-VI. Seven efficient chromium reducing bacterial strains were isolated as Bacillus korlensis, Bacillus subtilis, Bacillus cereus, Micrococcus luteus, Micrococcus varians, Enterobacter intermedius and Tatumella terrea. These bacteria reduced chromium in culture media at maximum 5 mM concentration within a period of 24–72 h as determined by 1, 5-diphenylcarbazide (DPC) colorimetric method. However, significant Cr-VI reduction or biodegradation was observed at 1.25 mM substrate concentration within 24 h at 37°C. The research was very promising for development of a microbiological process to be used in the removal of toxic hexavalent chromium from the environment.

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.


2008 ◽  
Vol 54 (6) ◽  
pp. 501-508 ◽  
Author(s):  
Karina Cogo ◽  
Michelle Franz Montan ◽  
Cristiane de Cássia Bergamaschi ◽  
Eduardo D. Andrade ◽  
Pedro Luiz Rosalen ◽  
...  

The aim of this in vitro study was to evaluate the effects of nicotine, cotinine, and caffeine on the viability of some oral bacterial species. It also evaluated the ability of these bacteria to metabolize those substances. Single-species biofilms of Streptococcus gordonii , Porphyromonas gingivalis , or Fusobacterium nucleatum and dual-species biofilms of S. gordonii – F. nucleatum and F. nucleatum – P. gingivalis were grown on hydroxyapatite discs. Seven species were studied as planktonic cells, including Streptococcus oralis , Streptococcus mitis , Propionibacterium acnes , Actinomyces naeslundii , and the species mentioned above. The viability of planktonic cells and biofilms was analyzed by susceptibility tests and time-kill assays, respectively, against different concentrations of nicotine, cotinine, and caffeine. High-performance liquid chromatography was performed to quantify nicotine, cotinine, and caffeine concentrations in the culture media after the assays. Susceptibility tests and viability assays showed that nicotine, cotinine, and caffeine cannot reduce or stimulate bacterial growth. High-performance liquid chromatography results showed that nicotine, cotinine, and caffeine concentrations were not altered after bacteria exposure. These findings indicate that nicotine, cotinine, and caffeine, in the concentrations used, cannot affect significantly the growth of these oral bacterial strains. Moreover, these species do not seem to metabolize these substances.


2020 ◽  
Vol 21 (3) ◽  
Author(s):  
Magdalena Woźniak ◽  
Lucyna Mrówczyńska ◽  
Anna Sip ◽  
Marta Babicka ◽  
Tomasz Rogoziński ◽  
...  

Introduction. Honey, propolis and pollen belong to bee products that have beneficial biological properties. These products exhibit e.g. antibacterial, antifungal and antioxidant properties. Due to biological activity and natural origin, bee products are used, e.g. in the food industry, cosmetology and pharmacy. Aim. The aim of the study was to compare the antioxidant and antibacterial activity of honey, propolis and pollen from an apiary located in Wielkopolska Province. Material and methods. Honey, propolis and pollen used in this study came from the same apiary located in Wielkopolska Province. The antioxidant potential of bee products was evaluated applying DPPH· free radical scavenging activity assay. The antimicrobial activity of the tested bee products was determined by the point-diffusion method against 13 strains of pathogenic and potentially pathogenic bacteria. In addition, the total content of phenolic compounds in honey, propolis and pollen was determined by the colorimetric method. Results. Propolis exhibited higher antioxidant activity, in comparison to honey and pollen. The antiradical activity of propolis was equal to 80% approx. activity of Trolox, the standard antioxidant. Among tested bee products, propolis was characterized by the highest total phenols content. In addition, honey, propolis and pollen showed antagonistic activity against tested bacterial strains. Conclusions. The obtained results indicate that among the tested bee products of native origin, i.e. honey, propolis and pollen, propolis characterized by the highest antioxidant activity and the total content of phenolic compounds. In addition, all bee products showed bactericidal activity against the tested bacterial strains.


1970 ◽  
Vol 32 (1) ◽  
pp. 41-53
Author(s):  
YN Jolly ◽  
A Islam ◽  
SB Quraishi ◽  
AI Mustafa

The impact of various dilutions (2.5, 5, 10, 25 and 50%) of paint industry effluent on physico-chemical properties of soil and the germination, growth and dry matter productions of corn (Zea mays L.) and rice (Oryza sativa L.) have been studied. The effluent was acidic and had low BOD and COD values because of its low content of suspended solid. It contained high concentration of calcium, medium concentrations of nitrogen, sodium, potassium, sulphate, chloride and low concentrations of phosphorus, magnesium and bicarbonate. The trace element like Mn, Ni, Cu, Zn and Pb were measured in the μg L-1 level. On irrigation of soil with the effluent an increase in the water soluble salts, pH, electrical conductivity, cation exchange capacity, nitrogen, phosphorus potassium, sodium, calcium, magnesium and iron contents of the soil for effluent concentrations of 2.5, 5 and 10% were observed but all these parameters were found to decrease on treatment of the soil with the effluent concentration of 25% and above. The effluent of the lower concentrations (2.5, 5 and 10%) enhanced the growth of both crops. However, negative effects on seed germination, dry matter production and the yield of both crops were found for the effluent concentration of 25% and above. doi: 10.3329/jbas.v32i1.2441 Journal of Bangladesh Academy of Sciences, Vol. 32, No. 1, 41-53, 2008


2020 ◽  
Vol 3 (1) ◽  
pp. 12-17
Author(s):  
Nahum Rosenberg ◽  

Introduction: Alternating and pulsed electromagnetic magnetic fields (AEMF and PEMF) of different amplitudes and frequencies can induce metabolic and proliferative effects in osteoblasts, but there is no clearly directed tendency of these effects. I hypothesize that there are extremely low triggering parameters of alternating electromagnetic field (EMF) intensity, i.e., above the background magnetic field on earth but below the lowest AEMF and PEMF that have been investigated to date (above 0.07 mT and below 0.4 mT) that induce cellular response. Methods: Accordingly, human monolayer explant culture replica were exposed four times in 24-hour intervals to two minutes of 10 kHz AEMF or PEMF (10 Hz pulses at a basic 5 kHz frequency) with a maximal EMF intensity of 0.2 mT for both. Cell proliferation was estimated from microscopic cell counting and cell death by lactate dehydrogenase (LDH) specific activity in culture media (measured using a colorimetric method). The early marker of osteoblast maturation, cellular alkaline phosphatase (AP) specific activity, was measured using a colorimetric method (n=6 for all experiment conditions). Results: No difference was found in cell numbers in the culture samples exposed either to AEMF or PEMF and in the LDH’s specific activity in culture media in comparison to the unexposed controls (p>0.05, for both). The cellular AP’s specific activity increased significantly only in cell cultures exposed to the 10 kHz AEMF (p=0.011). Conclusions: The triggering for human osteoblast activation for maturation by an extremely low AEMF (10 kHz) is at least 0.2 mT, which is distinct and below the previously found triggering range of a PEMF for proliferation induction. Therefore, application of these EMF parameters in a clinical setup by a separate finetuning of osteoblast proliferation and maturation might have a therapeutic value in enhancing damaged bone regeneration.


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.


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):  
D. Ivasenko ◽  
P. Bukhtiyarova ◽  
D. Antsiferov ◽  
Y. Frank

Analysis of fatty acid composition in liquid culture media after lipophilic bacterial strains cultivation was carried out. Pure cultures were earlierisolated from fat-containing wastes and cultivated on media with diverse fat sources. It was shown that microorganisms hydrolyze animal and milk fats to free fatty acids.


2012 ◽  
Vol 17 (1) ◽  
pp. 43 ◽  
Author(s):  
Jimena Paola Angulo-Cortés ◽  
Anamaría García-Díaz ◽  
Aura Marina Pedroza ◽  
María Mercedes Martínez-Salgado ◽  
Viviana Gutiérrez-Romero

<strong>Objective</strong>. To design a complex culture media for the production of biomass and acid phosphatases from phosphate-solubilizing bacteria isolated from soil. <strong>Materials</strong> <strong>and methods</strong>. Phosphate-solubilizing bacteria were isolated from oil palm crop soil samples and selected on SMRS1 agar, which were then assessed with antagonism tests to verify their aptitude to form a co-culture. A Box-Behnken experimental design was applied to<br />evaluate the effect of each one of the culture media components on the production of biomass and phosphatase enzymes at a laboratory scale. Finally, microbial growth and enzyme production curves were carried out in order to determine their production times. <strong>Results</strong>. Five phosphate-solubilizing bacterial strains were isolated and three of them were selected based on their solubilization indices.These Gram negative strains with bacillus morphology were identified as A, B and C; their solubilization indices were 2.03, 2.12, and 2.83, respectively. According to the ANOVA analyses for the Box-Behnken design, the only factor which had a significant effect on the phosphatase activity (p&lt;0.01) was hydrolyzed yeast, and the formulation that generated the highest biomass concentration and phosphatase activity (p&lt;0.01) contained 10, 15 and 2.5 gL-1 of phosphoric rock, sucrose and hydrolyzed yeast, respectively. After 24 hours of incubation at 100 rpm, the highest values of biomass and phosphatase activity were obtained: 11.8 logarithmic units of CFU and 12.9 phosphatase units. <strong>Conclusion</strong>. We determined that the culture media based on phosphoric rock 10 gL-1, hydrolyzed yeast 2.5 gL-1 and commercial sucrose 15 gL-1 was ideal for the production of biomass and phosphatases by the strains evaluated; likewise, we proved that the hydrolyzed yeast was the only factor significantly influential for the production of phosphatases.<br /><br /><strong>Key words</strong>: bio-inoculants, phosphate solubilizing microorganisms, phosphatase activity, Box Behnken design.


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