scholarly journals Evaluation of Lipases from Wild Microbial Strains as Biocatalysts in Biodiesel Production

Separations ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 53 ◽  
Author(s):  
Carlos Luna ◽  
Diego Luna ◽  
Felipa Bautista ◽  
Juan Calero ◽  
Antonio Romero ◽  
...  

In this study, the evaluation of the catalytic behavior of several wild bacterial strains in the 1,3-selective ethanolysis of triglycerides with ethanol to produce a new type of biodiesel (Ecodiesel) that integrates glycerol as monoacylglycerols was carried out. The Ecodiesel production not only avoids the elimination of glycerol, which is largely generated as a by-product in the biodiesel industry, but also results in an increase in the biofuel yield. The wild microbial strain samples were obtained from several lipophilic organisms. In addition to evaluate the enzymatic extracts, the minimum grade of purification of the strains, necessary to obtain similar results to those attained with commercial lipases was studied. This purification treatment included a dialysis followed by a lyophilization process. Such extracts were directly used as biocatalysts in the transesterification reaction of sunflower oil with ethanol, attaining much better results (yield close to 100%) than those obtained with strains which were not submitted to the purification process (yields lower than 10%). Furthermore, the results here obtained are similar to those obtained with commercial lipases but were achieved under mild conditions and lower reaction time (2 h). In addition, the stability of the enzymatic extracts was corroborated by subsequent reactions, showing no loss of activity. Thus, this study brings to light that enzymatic extracts obtained by a very simple purification process can be economically competitive with the conventional biodiesel production methods.

2021 ◽  
Vol 01 (01) ◽  
pp. 26-33
Author(s):  
Amos Ndarubu Tsado ◽  
Jiya A. Gboke ◽  
Habiba Ibrahim ◽  
David Gana ◽  
Danazumi Nathaniel ◽  
...  

Background: Microorganisms are the leading source of industrial proteases. As a result of this, researchers are searching for new microbial strain with novel characteristic for protease production. Methods: In this study, some microbial strains were isolated from a soil sample obtained from domestic waste dumpsite. The isolate was screened for protease activity using casein as substrate. The proteolytic isolates were identified and used for protease production. The optimum pH and temperature as well as kinetic parameters of the enzyme were determined to predict their suitable industrial applications. Results: Pseudomonas aeruginosa and Bacillus subtilis were identified to be active proteases producers. The optimum temperature of the Pseudomonas aeruginosa and Bacillus subtilis were both recorded at 50OC while the optimum pH of Pseudomonas aeruginosa and Bacillus subtilis were recorded at 8.0 and 9.0 respectively. The Km and Vmax of protease produced from Pseudomonas aeruginosa were 222.22U/ml and 0.625mg/ml respectively while the Km and Vmax were proteases produced from Bacillus subtilis were 135.13 U/ml and 0.402 mg/ml respectively. Conclusion: The results in this study suggest that domestic waste dumpsite could be a potential source of proteolytic isolates of novel characteristic.


2016 ◽  
Vol 5 (3) ◽  
pp. 38-43
Author(s):  
Windi Monica Surbakti ◽  
Gerson Rico M.H ◽  
Mersi Suriani Sinaga

Glycerol as a byproduct of biodiesel production was approximately formed 10% of the biodiesel weight. Impurities which contained in the glycerol such as catalyst, soap, methanol, water, salt, and matter organic non glycerol (MONG) have a significant effect on the glycerol concentration. So, it is necessary to treat the impurities. The purpose of this study is to know the effect of chloroform to glycerol purification process with acidification method using hydrochloric acid as pretreatment process. This research was begun with acid addition to the glycerol to neutralize the base content and to split the soap content into free fatty acid and salt, that are more easily separated from glycerol. Then the process was continued with extraction by the solvent chloroform using the variable of test volume ratio (v/v) (1:1, 1:1.5, 1:2)  and the extraction time (20, 40, and 60 minutes). The results showed that the more volume of solvent used, gave less extraction time to produce high purity of glycerol. The highest purity produced in this study amounted to 90,9082% is obtained at the ratio of the volume solvent (v/v) 1:1 with extraction time 60 minutes.


2020 ◽  
Vol 11 ◽  
pp. 37-43
Author(s):  
Prof. Teodora P. Popova ◽  
Toshka Petrova ◽  
Ignat Ignatov ◽  
Stoil Karadzhov

The antimicrobial action of the dietary supplement Oxidal® was tested using the classic Bauer and Kirby agar-gel diffusion method. Clinical and reference strains of Staphylococcus aureus and Escherichia coli were used in the studies. The tested dietary supplement showed a well-pronounced inhibitory effect against the microbial strains commensurable with that of the broad-spectrum chemotherapeutic agent Enrofloxacin and showed even higher activity than the broad spectrum antibiotic Thiamphenicol. The proven inhibitory effect of the tested dietary supplement against the examined pathogenic bacteria is in accordance with the established clinical effectiveness standards for antimicrobial agents.


2020 ◽  
Vol 4 (141) ◽  
pp. 114-122
Author(s):  
DAR’YA LEBEDEVA ◽  
◽  
ANNA KARPUNICHEVA

Large forces and significant thermal effects are created on the rolls when rolling sheets. The higher the stability of the rolls, the less downtime during their rerolling and higher productivity. (Research purpose) The research purpose is in analyzing the ways of restoring rolls and choose the most appropriate method for restoring these parts. (Materials and methods) The article presents the analysis of the scientific and technical literature on the topic of rolling production, methods for restoring large-sized machine parts of machine-building and metallurgical industries that work in difficult conditions and are subject to a high degree of wear. Authors try to solve the problem by means of comparative and logical analysis based on theoretical and empirical methods of scientific research. (Results and discussion) The article presents two groups of methods for restoring rolled rolls: banding and surfacing the working layer of the roll. Authors have analyzed each method in terms of technology, equipment, and feasibility. The article presents the advantages and disadvantages of the methods under consideration. (Conclusions) The most acceptable way to restore parts with a high degree of wear is surfacing. It is most efficient to apply submerged surfacing using an additional hot additive. Such surfacing, despite some complication of the equipment design, allows to deposit the metal on the roll with low heat input and in most cases in one pass. Surfacing using an additional hot additive allows to increase the productivity of the process by up to 250 percent while reducing the penetration depth by 2-3 times and saving energy by up to 40 percent.


RSC Advances ◽  
2020 ◽  
Vol 10 (45) ◽  
pp. 27183-27193
Author(s):  
Rose Fadzilah Abdullah ◽  
Umer Rashid ◽  
Yun Hin Taufiq-Yap ◽  
Mohd Lokman Ibrahim ◽  
Chawalit Ngamcharussrivichai ◽  
...  

The potential of bifunctional nanocatalysts obtained from waste palm kernel shell (PKS) was investigated for one-step transesterification–esterification under mild conditions.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Mydhili P. Sripathi ◽  
Sireesha Berely ◽  
Chittireddy Venkata Ramana Reddy

To understand the stability, chelation behaviour, and biological activity of 4-Formylpyridinethiosemicarbazone (H4FPT), it is important to recognize its interactive geometry. Hence, computational studies on geometrically optimized structures of thione and thiol forms of H4FPT were performed. Binary metal complexes of the ligand, H4FPT (L) with the Ni(II) and Cu(II) metal ions (M), were synthesized and characterized by various spectroanalytical techniques as elemental analysis, molar conductance, magnetic susceptibility measurements, LC-MS, TGA, IR, UV-Visible, ESR, and powder XRD. Elemental analysis, LC-MS, and TGA studies indicate 1:2 (ML2) composition for mononuclear Ni(II) complex and 1:1 (ML) composition for dinuclear Cu(II) complex. Electronic absorption titrations, fluorescence quenching studies, and viscosity measurements suggest intercalative mode of binding of the complexes with calf thymus DNA (CT-DNA). These complexes also promote hydrolytic cleavage of plasmid pBR322. The ligand (H4FPT) and its complexes showed moderate-to-good activity against Gram-positive and Gram-negative bacterial strains. The DPPH radical scavenging studies showed antioxidant nature of both complexes.


2021 ◽  
Author(s):  
Tianying Wang ◽  
Yanjun Zhou ◽  
Honglin Tang ◽  
Shihua Zhang ◽  
Haiqing Tian

Abstract The JCSM concept (short for Jackup Combined Semisubmersible Multifunction Platform) is a new type of semisubmersible platform presented by the first author, which overcomes the shortcomings of the available semisubmersible platforms, and combines the advantages of the traditional semisubmersible platform, the Jackup platform and the new FPSO concept - IQFP. Due to the complicated interaction between stability and hydrodynamic performance, it is necessary to explore the effect of geometrical parameters of the main body on the stability and hydrodynamic performance in order to obtain the optimal design plan of a JCSM platform. Firstly, the structure components and innovations of the JCSM were briefly reviewed in order to facilitate readers to understand its full picture. Then, six independent geometric parameters were selected by carefully studying the shape characteristics of the initial design plan of a JCSM study case. Furthermore, the stability heights and motion responses of various floating bodies of the JCSM case with different geometric parameters in wave were calculated using boundary element method based on potential flow theory. Lastly, effect of the shape parameters on stability and hydrodynamic performance of the JCSM was qualitatively evaluated. The research would shed lights on the shape design of the JCSM main body.


Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1026 ◽  
Author(s):  
Lihui Wang ◽  
Xinlong Liu ◽  
Yanjun Jiang ◽  
Peng Liu ◽  
Liya Zhou ◽  
...  

Enzymatic production of biodiesel had attracted much attention due to its high efficiency, mild conditions and environmental protection. However, the high cost of enzyme, poor solubility of methanol in oil and adsorption of glycerol onto the enzyme limited the popularization of the process. To address these problems, we developed a silica nanoflowers-stabilized Pickering emulsion as a biocatalysis platform with Candida antarctica lipase B (CALB) as model lipase for biodiesel production. Silica nanoflowers (SNFs) were synthesized in microemulsion and served as a carrier for CALB immobilization and then used as an emulsifier for constructing Pickering emulsion. The structure of SNFs and the biocatalytic Pickering emulsion (CALB@SNFs-PE) were characterized in detail. Experimental data about the methanolysis of waste oil to biodiesel was evaluated by response surface methodology. The highest experimental yield of 98.5 ± 0.5% was obtained under the optimized conditions: methanol/oil ratio of 2.63:1, a temperature of 45.97 °C, CALB@SNFs dosage of 33.24 mg and time of 8.11 h, which was closed to the predicted value (100.00%). Reusability test showed that CALB@SNFs-PE could retain 76.68% of its initial biodiesel yield after 15 cycles, which was better than that of free CALB and N435.


Author(s):  
Dafne Bongiorno ◽  
Nicolò Musso ◽  
Paolo Giuseppe Bonacci ◽  
Dalida A. Bivona ◽  
Mariacristina Massimino ◽  
...  

The widespread use of antibiotics has led to a gradual increase in drug-resistant bacterial infections, which severely weakens the clinical efficacy of antibacterial therapies. In recent decades, stilbenes aroused great interest because of their high bioavailability, as well as for their manifold biological activity. Our research efforts are focused on synthetic heteroaromatic stilbene deriva-tives as they represent a potentially new type of antibiotic with a wide antibacterial spectrum. Herein, a preliminary molecular modeling study and a versatile synthetic scheme allowed us to define eight heteroaromatic stilbene derivatives with potential antimicrobial activity. In order to evaluate our compound’s activity spectrum and antibacterial ability, Minimum Inhibitory Con-centration (MIC) and Minimum Bactericidal Concentration (MBC) tests have been performed on Gram-positive and Gram-negative ATCC strains. Compounds PB4, PB5, PB7 and PB8 showed the best values in terms of MIC and were also evaluated for MBC, which however was found to be greater than MIC, confirming a bacteriostatic activity. For all compounds, we evaluated toxici-ty on colon-rectal adenocarcinoma cells tumor cells (CaCo2), once established that the whole se-lected set was more active than 5-Fluorouracil in reducing CaCo-2 cells viability. To the best of our knowledge, the biological assays have shown for these derivatives an excellent bacteriostatic activity, compared to similar molecular structures previously reported, thus paving the way for a new class of antibiotic compounds.


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