Isolation and Identification of Crude Oil Degrading and Biosurfactant Producing Bacteria from the Oil-Contaminated Soils of Gachsaran

Background and Objectives: Petroleum hydrocarbons are harmful to the environment, human health, and all other living creatures. Oil and its byproducts in contact with water block sunshine to phytoplanktons and thus break the food chain and damage the marine food source. This study aims to isolate the crude oil degrading and biosurfactant producing bacteria from the oil contaminated soils of Gachsaran, Iran. Materials and Methods: Isolation was performed in peptone-water medium with yeast extract. Oil displacement area, emulsification index and bacterial phylogeny using 16S rRNA analysis were studied. Results and Conclusion: Three isolates were able to degrade the crude oil. In the first day, there were two phases in the medium; after a few days, these three bacteria degraded the crude oil until there was only one phase left in the medium. One strain was selected as a superior strain by homogenizing until the medium became clear and transparent. This method confirmed that the strain produces biosurfactant. According to the morphological and biochemical tests, the strain isolated from the oil contaminated soils is a member of Bacillus subtilis, so to study the bacterial phylogeny and taxonomy of the strain, an analysis of 16S rRNA was carried out, and the phylogenic tree confirmed them. The results verified that oil contaminated soils are good source for isolation of the biosurfactant producing bacteria

Individually and Synergistic Degradation of Hydrocarbons by Biosurfactant Producing Bacteria

Background: Increasing worldwide contamination with hydrocarbons has urged environmental remediation using biological agents such as bacteria. Our goal here was to study the phylogenetic relationship of two crude oil degrader bacteria and investigation of their ability to degrade hydrocarbons. Materials and Methods: Phylogenetic relationship of isolates was determined using morphological and biochemical characteristics and 16S rDNA gene sequencing. Optimum conditions of each isolate for crude oil degradation were investigated using one factor in time method. The rate of crude oil degradation by individual and consortium bacteria was assayed via Gas chromatography–mass spectrometry (GC-MS) analysis. Biosurfactant production was measured by Du Noüy ring method using Krüss-K6 tensiometer. Results: The isolates were identified as Dietzia cinnamea KA1 and Dietzia cinnamea AP and clustered separately, while both are closely related to each other and with other isolates of Dietzia cinnamea. The optimal conditions for D. cinnamea KA1 were 35°C, pH9.0, 510 mM NaCl, and minimal requirement of 46.5 mM NH4Cl and 2.10 mM NaH2PO4. In the case of D. cinnamea AP, the values were 30°C, pH8.0, 170 mM NaCl, and minimal requirement of 55.8 mM NH4Cl and 2.10 mM NaH2PO4, respectively. Gas chromatography – Mass Spectroscopy (GC-MS) analysis showed that both isolates were able to utilize various crude oil compounds, but D. cinnamea KA1 was more efficient individually and consortium of isolates was the most. The isolates were able to grow and produce biosurfactant when cultured in MSM supplemented with crude oil and optimization of MSM conditions lead to increase in biosurfactant production. Conclusion: To the best of our knowledge this is the first report of synergistic relationship between two strains of D. cinnamea in biodegradation of crude oil components, including poisonous and carcinogenic compound in a short time

Bioactivity of a Novel Glycolipid Produced by a Halophilic Buttiauxella sp. and Improving Submerged Fermentation Using a Response Surface Method

An antimicrobial glycolipid biosurfactant (GBS), extracted and identified from a marine bacterium, was studied to inhibit pathogenic microorganisms. Production of the GBS was optimized using a statistical method, a response surface method (RSM) with a central composite design (CCD) for obtaining maximum yields on a cost-effective substrate, molasses. The GBS-producing bacterium was identified as Buttiauxella Species in terms of biochemical and molecular characteristics. This compound showed a desirable antimicrobial activity against some pathogens such as E. coli, Bacillus subtilis, Bacillus cereus, Candida albicans, Aspergilus niger, Salmonella enterica. The rheological studies described the stability of the GBS at high values in a range of pH (7–8), temperature (20–60) and salinity (0%–3%). The statistical optimization of GBS fermentation was found to be pH 7, temperature 33 °C, Peptone 1%, NaCl 1% and molasses 1%. The potency of the GBS as an effective antimicrobial agent provides evidence for its use against food and human pathogens. Moreover, favorable production of the GBS in the presence of molasses as a cheap substrate and the feasibility of pilot scale fermentation using an RSM method could expand its uses in food, pharmaceutical products and oil industries

Statistical Methodologies for the Optimization of Lipase and Biosurfactant by Ochrobactrum intermedium Strain MZV101 in an Identical Medium for Detergent Applications

The Plackett–Burman design and the Box–Behnken design, statistical methodologies, were employed for the optimization lipase and biosurfactant production by Ochrobactrum intermedium strain MZV101 in an identical broth medium for detergent applications. Environmental factor pH determined to be most mutual significant variables on production. A high concentration of molasses at high temperature and pH has a negative effect on lipase and biosurfactant production by O. intermedium strain MZV101. The chosen mathematical method of medium optimization was sufficient for improving the industrial production of lipase and biosurfactant by bacteria, which were respectively increased 3.46- and 1.89-fold. The duration of maximum production became 24 h shorter, so it was fast and cost-saving. In conclusion, lipase and biosurfactant production by O. intermedium strain MZV101 in an identical culture medium at pH 10.5–11 and 50–60 °C, with 1 g/L of molasses, seemed to be economical, fast, and effective for the enhancement of yield percentage for use in detergent applications

Lipase and biosurfactant from Ochrobactrum intermedium strain MZV101 isolated by washing powder for detergent application

Abstract Background Alkaline thermostable lipase and biosurfactant producing bacteria are very interested at detergent applications, not only because of their eco-friendly characterize, but alsoproduction lipase and biosurfactant by using cheap materials. Ochrobactrum intermedium strain MZV101 was isolated as washing powder resistant, alkaline thermostable lipase and biosurfactant producing bacterium in order to use at detergent applications. Methods O. intermedium strain MZV101 produces was lipase and biosurfactant in the same media with pH 10 and temperature of 60 °C. Washing test and some detergent compatibility character of lipase enzyme and biosurfactant were assayed. The antimicrobial activity evaluated against various bacteria and fungi. Results Lipase and biosurfactant produced by O. intermedium strain MZV101 exhibited high stability at pH 10–13 and temperature of 70–90 °C, biosurfactant exhibits good stability at pH 9–13 and thermostability in all range. Both lipase and biosurfactant were found to be stable in the presence of different metal ions, detergents and organic solvents. The lipase enzyme extracted using isopropanol with yield of 69.2% and biosurfactant with ethanol emulsification index value of 70.99% and yield of 9.32 (g/l). The single band protein after through from G-50 Sephadex column on SDS-PAGE was calculated to be 99.42 kDa. Biosurfactant O. intermedium strain MZV101 exhibited good antimicrobial activity against Gram-negative bacteria and against various bacterial pathogens. Based upon washing test biosurfactant and lipase O. intermedium strain MZV101considered being strong oil removal. Conclusion The results of this study indicate that isolated lipase and biosurfactant with strong oil removal, antimicrobial activity and good stability could be useful for detergent applications. Graphical abstrac

Isolation and Identification of Phenanthrene-degrading Bacteria and Increasing the Biodegrading Ability by Synergistic Relationship

Background: Polycyclic aromatic hydrocarbons are a large group of oil contaminants with carcinogenic, mutagenic and teratogenic effects. The release of these compounds in soil destroys animals, plants and microbial diversity and has several negative impacts on physical properties of the soil including the destruction of soil aggregates reduction in pores, and increase in soil bulk density. Many strains of microorganisms isolated have the phenanthrene-degrading ability but this study focused on isolation and identification of a phenanthrene-degrader bacterium for bioremediation of contaminated soils. Background: Polycyclic aromatic hydrocarbons are a large group of oil contaminants with carcinogenic, mutagenic and teratogenic effects. The release of these compounds in soil destroys animals, plants and microbial diversity and has several negative impacts on physical properties of the soil including the destruction of soil aggregates reduction in pores, and increase in soil bulk density. Many strains of microorganisms isolated have the phenanthrene-degrading ability but this study focused on isolation and identification of a phenanthrene-degrader bacterium for bioremediation of contaminated soils. Materials and Methods: Enrichment technique was used for isolation and the most effective isolates, were named pseudomonas aeruginosa ZF1 and Serratia marcescens ZF2. The degradation experiments were conducted in the mineral salt medium (MSM) containing phenanthrene as the sole source of carbon and energy. The selection was based on phenanthrene biodegradation abilities. The isolates were identified using morphological, biochemical tests and 16S rDNA sequencing and after 10 days’ incubation at 30 °C and pH = 7, the bacterial growth and Phe-degrading rate were evaluated by protein assay (Bradford) and gas chromatography (GC), respectively. Results: Biochemical tests and 16s rDNA gene sequence analysis revealed that isolated bacteria are similar to Pseudomonas aeruginosa ZF1 and Serratia marcescens ZF2 with 99% similarity. The results showed a mixture of ZF1 and ZF2 bacteria could degrade 83% at minimum concentrations of 200 ppm of phenanthrene whereas single strain culture of two bacteria had poor degradation abilities (less than 15%). Conclusion: Results showed that isolated co-culture bacteria have high potential to degrade phenanthrene with the best results achieved when the enriched consortium was used and this mixture was shown to be an appropriate candidate for bioremediation purposes

Biodegradation of malathion by serratia marcescens isolated from Arvandkenar region, Iran

The global use of pesticides has resulted in the contamination of various ecosystems worldwide. The impact of these pesticides can be reduced through bioremediation. The factors that influence the biodegradation rate include the isolation of efficient bacteria for use in remediation and the determination of optimal biodegradation conditions. In this study, malathion degrading bacteria were isolated from agricultural soil samples taken from the Arvandkenar region in Iran. To optimize the biodegradation of malathion by an isolated strain, the effect of four parameters (temperature, salinity, NH4Cl and K2HPO4) was evaluated while considering protein concentrations at different times. The malathion remaining in the media was measured using the gas chromatography method. A gram-negative bacterium strain BNA1 with malathion biodegrading ability was isolated from the soil sample which showed a 99% similarity to Serratia marcescens. The optimum biodegradation condition occurred at a temperature = 30 ˚C, salinity = 0 %, NH4Cl = 0.25 g/L and K2HPO4 = 0.25 g/L. A biodegradation efficiency of 65% was obtained under the above-mentioned condition. The results of this study revealed the significant capability of BNA1 in the biodegradation of malathion. Therefore, the use of an isolated strain may be considered as an important tool in the bioremediation of pesticide-contaminated soil

Evaluation of Aliphatic and Aromatic Compounds Degradation by Indigenous Bacteria Isolated from Soil Contaminated with Petroleum

Background:  The major of this study was to isolate oil-degrading bacteria from soil contaminated with petroleum and examining the removal of hydrocarbons by these bacteria. Methods: Oil-degrading colonies were purified from the samples obtained of around Ahvaz oil wells. Organic matter degradation was investigated with 1 g of crude oil in basal salt medium (BSM) as sole carbon source. The growth rate was determined through total protein assay and hydrocarbon consuming was measured through organic carbon oxidation and titration by dichromate as oxidizing agent. Results: Two potential isolates named S1 and S2 strains were screened and identified as Planococcus and Pseudomonas aeruginosa. As results for S1 and S2 could degrade 80.86 and 65.6% of olive oil, 59.6 and 35.33 of crude oil, while 32 and 26.15 % of coal tar were consumed during 14 days incubation. Conclusion: The results of this investigation showed these indigenous strains high capability to biodegradation at short time and are desirable alternatives for treatment of oil pollutants

Optimization of Phenanthrene-degradation by Dietzia Cinnamea AP for Bioremediation Applications

Background: This study focused on isolation and identification of a Phenanthrene (Phe) degrader bacterium and optimization of environmental conditions for Phe degradation. Materials and Methods: Enrichment technique was used for isolation and the most effective isolate; named AP was selected based on its Phe biodegradation abilities. The isolate was identified using morphological and biochemical tests as well as16S rDNA sequencing. The effects of various factors such as temperature, pH and C/N on bacterial growth and Phe degradation were investigated using protein assay (Bradford) and Gas Chromatography (GC), respectively. Results: The selected isolate was identified as Dietzia cinnamea AP. It was able to degrade Phe at pH 6-10 (optimum at 8), temperatures of 25 -45 °C (optimum at 35 °C) and NH4Cl concentrations of 0.5-2.5 gL-1 (optimum at 2 g L-1). By optimization of environmental parameters, within 10 days of fermentation, Phe degradation rate increased by more than 1.2 fold (from 60% to 73%). Conclusion: D. cinnamea AP was found to be an appropriate candidate for bioremediation applications. To the best of our knowledge, this is the first report of D. cinnamea species that can degrade Phe

Surveying the Antioxidant and the Antimicrobial Effects of Aqueous and Ethanolic Extract of Rumex Alveollatus L. on In-vitro Indicator Microorganisms

Background & Objective: In recent years, more attention has been devoted to herbal medicines. Up to now, many compounds with therapeutic effects has been extracted from the herbs. The aim of this study is to evaluate the antioxidant and the antimicrobial effect of Rumex Alveollatus L. and to partially identify the effective compounds in this plant. Materials & Methods: Extraction was performed by using maceration method for dried flower sample. Then, the antimicrobial effect of aqueous and ethanolic extracts on eight bacterial sp. and two fungi were tested using disc diffusion method. The antioxidant effect was also determined through ferric reducing potency and phosphomolybdenum followed by total phenol determination. Finally, partial detection of bioactive compounds was conducted using chemical and calorimetric methods.  Results: The results showed that ethanolic extract had the most antimicrobial effect; while aqueous extract weakly affected bacterial and fungal strains. Antioxidant experiments also revealed that ethanol extract had more antioxidant effects than aqueous extract. The most content of total phenolic compounds was found in ethanol extract. The results of the plant chemical determination showed the presence of flavonoids, alkaloids, anthraquinones, tannins, glycosides, and reducing sugars. Conclusion: Considering that few reports about the therapeutic effect of Rumex alveollatus L. has been published, this study could be considered as a valuable report about the important role of this plant on preventing infections and neutralizing oxidant agents