Biosurfactants: Promising Molecules for Petroleum Biotechnology Advances

The growing global demand for sustainable technologies that improves the efficiency of petrochemical processes in the oil industry has driven advances in petroleum biotechnology in recent years. Petroleum industry uses substantial amounts of petrochemical-based synthetic surfactants in its activities as mobilizing agents to increase the availability or recovery of hydrocarbons as well as many other applications related to extraction, treatment, cleaning and transportation. However, biosurfactants have several potential applications for use across the oil processing chain and in the formulations of petrochemical products such as emulsifying/demulsifying agents, anticorrosive, biocides for sulphate-reducing bacteria, fuel formulation, extraction of bitumen from tar sands and many other innovative applications. Due to their versatility and proven efficiency, biosurfactants are often presented as valuable versatile tools that can transform and modernise petroleum biotechnology in an attempt to provide a true picture of state of the art and directions or use in the oil industry. We believe that biosurfactants are going to have a significant role in many future applications in the oil industries and in this review therefore, we highlight recent important relevant applications, patents disclosures and potential future applications for biosurfactants in petroleum and related industries

Preferential binding of unsaturated hydrocarbons in aryl-bisimidazolium·cucurbit[8]uril complexes furbishes evidence for small-molecule Π−Π\Pi-\Pi interactions

Whilst cucurbit[n]urils (CBn) have been utilized in gas encapsulation, only the smaller CBn (n = 5 and 6) have utility given their small cavity size. In this work, we demonstrate that the large cavity of CB8 can be tailored for gaseous and volatile hydrocarbon encapsulation by restricting its internal cavity size with auxiliary aryl-bisimidazolium (Bis, aryl = phenyl, naphthyl, and biphenyl) guests. The binding constants for light hydrocarbons $C \le 4$ are similar to those measured with CB6, while larger values are obtained with Bis·CB8 for larger guests. A clear propensity for higher affinities of alkenes relative to alkanes is observed, most pronounced with the largest delocalized naphthalene residue in the auxiliary Bis guest, which provides unique evidence for sizable small-molecule $\Pi-\Pi$ interactions

In silico exploration of Red Sea Bacillus genomes for natural product biosynthetic gene clusters

Background: The increasing spectrum of multidrug-resistant bacteria is a major global public health concern, necessitating discovery of novel antimicrobial agents. Here, members of the genus Bacillus are investigated as a potentially attractive source of novel antibiotics due to their broad spectrum of antimicrobial activities. We specifically focus on a computational analysis of the distinctive biosynthetic potential of Bacillus paralicheniformis strains isolated from the Red Sea, an ecosystem exposed to adverse, highly saline and hot conditions. Results: We report the complete circular and annotated genomes of two Red Sea strains, B. paralicheniformis Bac48 isolated from mangrove mud and B. paralicheniformis Bac84 isolated from microbial mat collected from Rabigh Harbor Lagoon in Saudi Arabia. Comparing the genomes of B. paralicheniformis Bac48 and B. paralicheniformis Bac84 with nine publicly available complete genomes of B. licheniformis and three genomes of B. paralicheniformis, revealed that all of the B. paralicheniformis strains in this study are more enriched in nonribosomal peptides (NRPs). We further report the first computationally identified trans-acyltransferase (trans-AT) nonribosomal peptide synthetase/polyketide synthase (PKS/ NRPS) cluster in strains of this species. Conclusions:B. paralicheniformis species have more genes associated with biosynthesis of antimicrobial bioactive compounds than other previously characterized species of B. licheniformis, which suggests that these species are better potential sources for novel antibiotics. Moreover, the genome of the Red Sea strain B. paralicheniformis Bac48 is more enriched in modular PKS genes compared to B. licheniformis strains and other B. paralicheniformis strains. This may be linked to adaptations that strains surviving in the Red Sea underwent to survive in the relatively hot and saline ecosystems

Selection of Pseudomonas aeruginosa for biosurfactant production and studies of its antimicrobial activity

Biosurfactants are generally microbial metabolites with the typical amphiphilic structure of a surfactant. This study investigated potential biosurfactants production of Pseudomonas aeruginosa ATCC-10145 and Bacillus subtilis NCTC-1040 using glucose and n-hexadecane as substrates separately and compared it with the production in conventional medium. Pseudomonas aeruginosa growing in BHMS (Bushnell hass mineral salt) medium with glucose as substrate decreased the surface tension from 72 of distilled water to 32 mN/m, this strain had higher reduction than Bacillus subtilis among all the substrates tested. The selection of Pseudomonas aeruginosa for the separation of biosurfactant was determined. The crude biosurfactant was extracted from the supernatant and the yield of the crude biosurfactant was about 1 g/l. Some surface properties of rhamnolipids biosurfactant were evaluated. It also showed antimicrobial activity against different bacteria and fungi strains. The crude biosurfactant showed good action as antimicrobial activity against different bacterial and fungal species

Effect of Diospyros kaki enriched extender on cattle bull sperm parameters and conception rate

Objective: To explore the effect of Diospyros kaki on cattle spermatozoa during chilling and cryopreservation.Methods: Five milliliter of blended Persimmon (Diospyros kaki) flesh was added to 45 mL TCF to obtain 10% stock solution. Kaki enriched extender (KEE) was prepared by adding to TCF in concentrations 0.0/5.0 mL (control, 0%), 0.5/4.5 mL (1%), 1/4 mL (2%), 1.5/3.5 mL (3%), 2.0/3.0 mL (4%), 2.5/2.5 mL (5%), 3.0/2.0 mL (6%), 3.5/1.5 mL (7%), 4.0/1.0 mL (8%), 4.5/0.5 mL (9%) and 5.0/0.0 mL (10%) to obtain a final volume 5 mL in each tube. Whole egg yolk was added to each tube to obtain KEE with 20% egg yolk (KEEY), all tubes were centrifuged to get rid of debris. Semen was added to the supernatants in other tubes. Extended semen was subjected to evaluation [motility, alive sperm and intact sperm membrane (HOST) %] in both chilled and cryopreserved semen. Conception rate was carried out.Results: Sperm motility was significantly (P<0.000 1) kept high after 11 d of chilling with the concentration 1%, 2%, 3%, 4%, 5% as compared to the control (41.67±1.67, 41.67±1.67, 40.00±0.00, 41.67±1.67 and 41.67±1.67, respectively) and also non-significantly kept high at the other concentrations up to 9 d of chilling. Addition of KEE had significantly (P<0.003 3) improved post thawing sperm motility % with the concentrations 1, 2, 3, 4, 5 and 6% as compared to the control (51.67±5.27, 55.00±3.16, 48.33±1.05, 45.00±3.96, 57.00±2.50, 55.00±5.00 and 43.33±5.11 respectively).While the other concentrations exhibit no effect. Addition of KEE maintained alive sperm%, abnormalities% and % of intact spermatozoa membranes (HOST%) as good as the control with all concentrations of kaki used in our study. The conception rate upon using frozen semen in insemination showed higher conception rate in concentrations of 2%, 4% and 6 % KEE in cattle.Conclusion: It could be concluded that some concentrations of Diospyros kaki improved bull semen quality post-chilling and post-freezing

Effect of tris-extender supplemented with various concentrations of strawberry (Fragaria spp.) on bull semen preservability

Objective: To evaluate effect of tris-extender supplemented with various concentrations of strawberry (Fragaria spp.) on bull semen preservability.Methods: Pooled bull semen were extended with tris-citrate-fructose egg yolk diluent (control, 0% strawberry) and various concentrations of tris strawberry (TSB) (1%-6%) to achieve 60 million motile spermatozoa per milliliter. Extended semen were subjected to semen freezing protocol. Semen assessment including motility, alive%, abnormality%, intact sperm membrane (hypo-osmotic swelling test) and conception rate were carried out for both chilled and frozen semen.Results: Results showed that sperm motility after chilling was enhanced in groups treated with various concentrations of TSB from 1% to 5% and exhibited higher significance (P<0.000 1) at 6-day post-chilling. In frozen semen, 3%, 4%, 5% and 6% concentrations gave the best significance (P<0.000 1) on sperm motility in comparison with the control. Concentration 1% revealed the highest significance (P<0.000 1) on alive% as compared to the control. Hypo- osmotic swelling test was maintained as the control. Concentration 3% gave the lowest significance (P<0.000 1) considering abnormality%. The conception rate upon using frozen semen in insemination showed higher conception rate in concentrations of 5% and 6% in cattle.Conclusions: It is concluded that 1%-5% concentrations of TSB ameliorate bull semen characteristics after chilling, and 3%-6% concentrations of TSB improve bull semen characteristics after freezing. Higher conception rate exists in 5% and 6% concentration of TSB

Impact of Silymarin enriched semen extender on bull sperm preservability

Objective: To explore the effect of silymarin on bull spermatozoa during cooling and cryopreservation.Methods: Pooled bull semen were diluted by Tris-Citrate-Fructose egg yolk diluents, purified silymarin powder (obtained from the milk thistle silybum marianum), purchased from Unipharma, Al Obour city, Egypt, was soaked in Tris-citric acid-fructose diluent for 48 h at 10 °C making a stock solution (70 mg/mL), from this stock solution we obtained concentrations of 0.18 mg/mL, 0.36 mg/mL, 0.54 mg/mL, 0.72 mg/mL, 0.90 mg/mL in addition to the control (0.00 mg/mL) reaching a final volume of 5 mL in each tube. Egg yolk was added to each tube to obtain silymarin enriched semen extender (SEE) with 20% egg yolk, cooled slowly up to 5 °C and equilibrated for 4 h. Semen was packed into 0.25 mL polyvinyl French straws (IMV, France). After equilibration periods, the straws were placed horizontally on a rack and frozen in a vapor 4 cm above liquid nitrogen for 10 min and were then dipped in liquid nitrogen. Extended semen was subjected to evaluation (motility, alive%, abnormality%, intact sperm membrane (HOST)% and conception rate) in both chilled and frozen semen.Results: [Table 1] revealed that Sperm motility of the concentrations 2, 3 and 4 after 8 d of chilling were significantly (P<0.02) higher than control. Sperm motility of the concentration 2 (45.00%±2.89%) after 9 d of chilling was higher than control and the other concentrations. Addition of SEE in concentration 1 and 2 gave post thawing sperm motility as high as the control (47.50±2.81 and 45.00±2.58, respectively) while other concentration have lower effects on motility as compared to the control. Addition of silymarin improved post thawing alive% and was significantly higher (P<0.000 1) than the control. SEE decreased significantly (P<0.000 1) the % of post thawing abnormal sperm in concentration 3 and 4 (11.83±0.65 and 16.00±0.58, respectively). SEE improved significantly (P<0.018) the % of post thawing intact spermatozoa membranes (HOST%) in concentrations 2, 4 and 5 (71.17±0.83, 71.83±0.91 and 75.00±3.42, respectively) [Table 2].Conclusion: It could be concluded that silymarin as a natural additive to semen extenders improved preservability in both chilled and frozen bull semen