Evaluation of anti-biofouling potential of Viburnum opulus extracts / Evaluación del potencial anti bioincrustante de extractos de Viburnum opulus

In this study the in vitro investigation of the inhibitory effect of ethanol extract of Viburnum opulus L. bark sample on Streptococcus mutans planctonic cells and biofilm has been intended. A Scanning electron microscopy analysis has been performed in order to investigate the inhibitory effect of the extract on Streptococcus mutans biofilms. Furthermore, the Exopolysaccharide and dextran production of this bacteria have been identified in the presence of the extract. It has been found out that the bark extract with the concentration of 2,5 mg/mL is able to inhibit more than 50% of the cells in the different times development phases. According to this, the exopolymeric matrix on the biofilm surface disperses and the Exopolysaccharide and dextran production get lowered in the presence of bark extract compared to the control group. It is considered that this extract can be used as an alternative approach for the new chemotherapeutic strategies against tooth decay.

En este estudio se investigó el efecto inhibitorio in vitro del extracto de etanólico de una muestra de corteza de Viburnum opulus L. en biopelículas de células planctónicas de Streptococcus mutans. Se realizó un análisis de microscopía electrónica de barrido para investigar el efecto inhibitorio del extracto sobre las biopelículas de Streptococcus mutans. Además, se identificó la producción de exopolisacárido y dextrano de esta bacteria en presencia del extracto. Se descubrió que el extracto de corteza con una concentración de 2,5 mg/ml inhibió más del 50% de las células en las diferentes fases de desarrollo. Consecuentemente, la matriz exopolimérica en la superficie de la biopelícula se dispersa y la producción de exopolisacárido y dextrano se reduce en presencia de extracto de corteza en comparación con el grupo de control. Se sugiere que este extracto puede ser usado como un enfoque alternativo para las nuevas estrategias quimioterapéuticas contra la carie dental.

In vitro Antimicrobial and Antioxidant Properties of Ganoderma lucidum Extracts Grown in Turkey.

Aim: To determine antimicrobial and antioxidative effects of Ganoderma lucidum. Place and Duration of Study: Erciyes University, Faculty of Pharmacy, Pharmaceutical Biotechnology research laboratory,Kayseri, Turkey, between January to March, 2013. Methodology: Antimicrobial inhibitory effects were carried out on the extracts using disc diffusion method. Antioxidant activities of the ethanolic and methanolic extracts from G.lucidum were evaluated by using 2,2-diphenyl-1-picrylhydrazyl [DPPH] radical scavenging, metal chelating, total flavonoid and total antioxidant activity assays. In addition, the amounts of phenolic compound, β-carotene and lycopene components in the extracts were determined. Results: The antimicrobial effects of ethanolic and methanolic extracts of G. lucidum were tested against one species of Gram positive bacteria, two species of Gram-negative bacteria and two yeast. The highest inhibitory activity was determined against Candida glabrata RSKK 04019 [25±1 mm, inhibition zone diameter]. On the other hand, the lowest inhibitory activity was determined against Candida albicans ATCC 90028 and Bacillus subtilis RSKK 244 [10±1 and 10±0 mm, inhibition zone diameter]. DPPH radical scavenging effect was detected in the methanol extract [IC50 = 3.82±0.04 μg/mL] was higher than the ethanol extracts [IC50 = 7.03±0.07 μg/mL]. Compared to reference antioxidant, the methanol and ethanol extracts of G.lucidum provided a lower IC50 than butylated hydoxyanisole [BHA] [IC50 = 0.30±0.01 μg/mL]. Phenolic compounds were the major antioxidant component found in the mushroom extracts. Conclusion: These results showed that G. lucidum may be used in pharmaceutical applications because of its effective antioxidant properties.

Enhanced crude oil biodegradation and rhamnolipid production by Pseudomonas stutzeri strain G11 in the presence of Tween-80 and Triton X-100.

In this study, the growth of sixty-one bacterial strains in crude oil were determined spectrophotometrically at 620 nm. Pseudomonas aeruginosa G1, Pseudomonas fluorescens G6, Pseudomonas stutzeri G11 and Pseudomonas putida G15 were chosen for the study based on the efficiency of crude oil utilisation. At 1% (v/v) crude oil concentration, P. stutzeri G11 strain degraded a maximum of 69%. The percentage of degradation by the P. stutzeri G11 strain decreased from 69% to 59% as the concentration of crude oil was increased from 1% (v/v) to 2.5% (v/v). Strain G11 was selected to determine the effects of surfactants (Tween-80 and TritonX-100) on the biodegradation of crude oil. While strain G11 showed 76% degradation at mineral salts medium (MSM) containing 1% (v/v) crude oil + 1% (v/v) TritonX-100, it showed 61% degradation at MSM containing 2.5% (v/v) crude oil + 2.5% (v/v) TritonX-100. Also, degradation rate of this strain was 96% in the presence of 1% (v/v) crude oil + 1% (v/v) Tween-80, while degradation rate was 48% in the presence of 25% (v/v) crude oil+ 2.5% (v/v) Tween-80. Additionally, we investigated the rhamnolipid production of P. stutzeri G11 strain both in crude oil and in crude oil + two different surfactants (TritonX-100 and Tween-80, separately). These results suggest that surfactants have improved both crude oil degradation and rhamnolipid production and the degradation rates have depended very much on the chemical structure of surfactants.