Heat-induced overexpression of the thermophilic lipase from Bacillus thermocatenulatus in Escherichia coli by fermentation and its application in preparation biodiesel using rapeseed oil

A UHPLC-QE-MS-based metabolomics approach for the evaluation of fermented lipase by an engineered Escherichia coli

Using an engineered Escherichia coli to produce lipase and can easily achieve high-level expression. The investigation of biochemical processes during lipase fermentation, approached from a metabolomics perspective, will yield novel insights into the efficient secretion of recombinant proteins. In this study, the lipase batch fermentation was carried out first with enzyme activity of 36.83 U/mg cells. Then, differential metabolites and metabolic pathways were identified using an untargeted metabolomics approach through comparative analysis of various fermentation periods. In total, 574 metabolites were identified: 545 were up-regulated and 29 were down-regulated, mainly in 153 organic acids and derivatives, 160 organoheterocyclic compounds, 64 lipids and lipid-like molecules, and 58 organic oxygen compounds. Through metabolic pathways and network analysis, it could be found that tryptophan metabolism was of great significance to lipase production, which could affect the secretion and synthesis of recombinant protein. In addition, the promotion effects of cell growth by varying concentrations of indole acetic acid serve to validate the results obtained from tryptophan metabolism. This study offers valuable insights into metabolic regulation of engineered E. coli, indicating that its fermentation bioprocess can be systematically designed according to metabolomics findings to enhance recombinant protein production.

Production, purification, properties and current perspectives for modification and application of microbial lipases

With the industrialization and development of modern science, the application of enzymes as green and environmentally friendly biocatalysts in industry has been increased widely. Among them, lipase (EC. 3.1.1.3) is a very prominent biocatalyst, which has the ability to catalyze the hydrolysis and synthesis of ester compounds. Many lipases have been isolated from various sources, such as animals, plants and microorganisms, among which microbial lipase is the enzyme with the most diverse enzymatic properties and great industrial application potential. It therefore has promising applications in many industries, such as food and beverages, waste treatment, biofuels, leather, textiles, detergent formulations, ester synthesis, pharmaceuticals and medicine. Although many microbial lipases have been isolated and characterized, only some of them have been commercially exploited. In order to cope with the growing industrial demands and overcome these shortcomings to replace traditional chemical catalysts, the preparation of new lipases with thermal/acid-base stability, regioselectivity, organic solvent tolerance, high activity and yield, and reusability through excavation and modification has become a hot research topic.

High-Level Production of Recombinant Lipase by Fed-Batch Fermentation in Escherichia coli and Its Application in Biodiesel Synthesis from Waste Cooking Oils

The enzymatic production of biodiesel from waste cooking oils (WCOs) offers a green and sustainable solution for the liquid fuel manufacture as well as waste resource recovery. In present study, liquid lipase was used to simplify the catalysis process, thereby reducing biodiesel production costs. An engineered Escherichia coli expressing Geobacillus thermocatenulatus lipase 2 (GTL2) was screened at an enzyme activity of 6.96 U/mg, after evaluating the propagating stability of the recombinant plasmids exceeding 86.11%. Through the beneficial feeding strategy and effective pH control, high-level production of GTL2 by fed-batch fermentation was achieved with an enzyme activity of 434.32 U/mg, which was almost 62 times that of shake flask fermentation. In addition, liquid GTL2 was used to prepare fatty acid methyl esters (FAMEs) using WCOs. The effects of the reaction time, catalyst loading, temperature, and methanol-to-oil molar ratio on FAMEs production using WCOs were explored, and a maximum FAMEs yield of 96.62% was achieved under optimized conditions. These results indicate that liquid GTL2 is a promising biocatalyst for efficient utilization of WCOs in the synthesis of biodiesel and provide a novel enzymatic process for biodiesel reducing the cost of production.

Extremophilic lipases for industrial applications: A general review

With industrialization and development in modern science enzymes and their applications increased widely. There is always a hunt for new proficient enzymes with novel properties to meet specific needs of various industrial sectors. Along with the high efficiency, the green and eco-friendly side of enzymes attracts human attention, as they form a true answer to counter the hazardous and toxic conventional industrial catalyst. Lipases have always earned industrial attention due to the broad range of hydrolytic and synthetic reactions they catalyse. When these catalytic properties get accompanied by features like temperature stability, pH stability, and solvent stability lipases becomes an appropriate tool for use in many industrial processes. Extremophilic lipases offer the same, thermostable: hot and cold active thermophilic and psychrophilic lipases, acid and alkali resistant and active acidophilic and alkaliphilic lipases, and salt tolerant halophilic lipases form excellent biocatalyst for detergent formulations, biofuel synthesis, ester synthesis, food processing, pharmaceuticals, leather, and paper industry. An interesting application of these lipases is in the bioremediation of lipid waste in harsh environments. The review gives a brief account on various extremophilic lipases with emphasis on thermophilic, psychrophilic, halophilic, alkaliphilic, and acidophilic lipases, their sources, biochemical properties, and potential applications in recent decades.