Current Biochemical Engineering (Discontinued) - Volume 4, Issue 2, 2017

Background: Enzymes are biomolecules functioning as catalysts accelerating the speed of specific reactions. Increasing global population, lifestyle trends, biofuels and chemical/pharmaceutical applications have positive impacts on global demand for new industrial enzymes. The global market of enzymes has been growing, which is estimated in 2015 to be about 3.7 billion USD with a 10% expansion. Objectives: In this review, we discuss the thermophilic and hyperthermophilic enzymes with respect to their sources, applications, and methods for improvement. Prospective enzymes that have potential industrial applications and industries that need new candidate thermophilic enzymes will also be presented. Results: Research, reports and online contents related to industrial enzymes are reviewed. Industrial enzymes have many applications such as detergent, food, animal feed, cosmetics, biofuel, medication, pharmaceuticals, technical use, and tools for research and development. Commercially available microbial enzymes are about 200 out of almost 4,000 enzymes known. The recent increase in the global environmental awareness requires industry with environmentally friendly conditions and as-low-aspossible energy consumption, which shed light on the benefits of using enzymes. Microorganisms are major sources for industrial enzymes, especially thermophilic and hyperthermophilic microbes. Thermostable enzymes have many desirable characteristics such as thermostability, wide range of pH tolerance and resistance to organic solvents, which make them superior for industrial applications. Conclusion: Thermophilic and hyperthermophilic enzymes represent a superior source for industrial applications. More efforts are needed for increasing the implementation of thermophilic and hyperthermophilic enzymes in industries, and screening for new enzymes from different sources and creating new methods for harnessing these enzymes for more industrial applications.

Background: Mustard oil, due to its high erucic acid content, should not be preferred as edible oil. Rather, fatty acids present in its triacylglycerol structure can be used in various fields. Structured lipids can also be formed from this oil and such compounds also have important applications, particularly in foods. Methods: Processes like hydrolysis can lead to production of free fatty acids. Alcoholysis can lead to biodiesel. Transesterification can result in concentration of erucic acid in alkyl fatty acid ester fraction and 18-carbon fatty acids in combination of acetylacyl and acylglycerol fraction. Biocatalyst like lipase (enzyme) is a better alternative to chemical catalyst regarding product quality, moderate process conditions and product selectivity. Results: Studies of various research groups on lipase catalyzed processes leading to modification of mustard oil have been presented in a concise form in this review. Process variables like water content, time and additives like surfactants, salts and organic solvents affected the aforesaid processes. Statistical optimization of hydrolysis in the presence of surfactants sufficiently enhanced erucic acid concentration in free fatty acid fraction. Conclusion: The studies represented in this review work give detailed idea on different kinds of possible applications of products derived from mustard oil. Type of lipase, process conditions and additives necessary for best outcome can also be identified for each process from this review work.

Background: Biodiesel represents an interesting alternative to fossil fuels. Traditionally the standard method for biodiesel production from oils is alkaline - catalyzed transesterification. Chemical catalysis can be replaced by enzymatic catalysis using lipases (EC 3.1.1.3, triacylglycerol acyl hydrolases), obtained from plants, animals or microorganisms. Enzymatic catalysis has important advantages compared to chemical catalysis, as lower energy consumption and undesirable side-reactions do not occur originating pure compounds. However, some problems should be overcome to achieve a real alternative to chemical catalysis, such as the prize, the stability, and the reutilization of the biocatalyst. Results: The review consists of an update of the state of the art of enzymatic biodiesel production, including legislation, feedstocks, lipases used for biodiesel synthesis, the role of acyl acceptors and strategies to avoid lipase inactivation, the mechanisms proposed for biocatalysis and the enzymatic bioreactors used. In addition, the economics of the bioprocess is also presented. Conclusion: Nowadays, there are already some examples of enzymatic processes for biodiesel production implemented at industrial scale and the number of pilot and industrial scale plants has greatly increased in the recent years. In spite of this trend, the chemical catalysis process still remains the most popular on an industrial scale mainly due to the high cost of commercial lipases. Thus, it is necessary to improve the enzymatic technology, increasing the productivity of the bioprocess and reducing the cost of the bioprocess. To attain this goal, it is necessary to act in a multidisciplinary approach of Genetic engineering, Bioprocess engineering, including the production of recombinant lipase in the most adequate cell factory, Enzyme engineering and applied Biocatalysis. It is a fact that the approach to “create” by genetic engineering, a lipase with a high tolerance to methanol, high biocatalyic performance and high resistance to work at higher temperatures and under harsh conditions is not corresponding with the important advances as compared to the other aspects. Also, the use of low cost non-commercial biocatalysts, presenting both high transesterification activity and operational stability, as an alternative to commercial biocatalysts, is a solution to reduce enzymatic biodiesel production costs, making it competitive with chemical processes. The price of biodiesel is highly affected by the market price fluctuation of oil feedstock. Thus the commercial efficiency and competitiveness of biodiesel market needs the development of high-valued product from the FAMEs as rawmaterial, under the concept of a biodiesel refinery. Other approach to minimize the cost of the global process is the production of heterologous lipases, using the crude glycerol obtained in the same biodiesel industry, without high purification, as carbon source. The presence of low methanol concentration and other possible contaminants jointly in the matrix of crude glycerol is not a problem for P. pastoris, one of the most popular cell factories to produce recombinant lipases. In conclusion, enzymatic biodiesel, as a green alternative to chemical biodiesel, has a potential economic growth in the near future.

Background: Biofilm packed bed reactors are used to enhance the lactic acid yield. The process involves the employment of Lactobacillus casei, Lacto bacillus rhamnosus, and Rhamnosusoryzae in combination on ceramic beads immobilized with Streptomyces. The reaction did not produce proper product since a fall in pH was observed with the production of lactic acid. Hence a pH gradient was observed through the interval of the reactor column. To maintain proper pH throughout reactor suitable continuous production type of reactor can be used for the lactic acid- formation. Further, lab scale procedure was compared with immobilization and without immobilization. Methods: In our work, this innovative method has been used for the enhancement of the lactic acid, which is a continuous production of lactic acid by immobilizing the mixed cultures of L. casei , L rhamnosus, and R. oryzae with ceramic beads along with the biofilm development using streptomyces viridosporus culture. The outcome has witnessed an improved productivity of the desired product when compared with lactic acid production by using pure culture which was immobilized. Results: Lactic acid production in a packed bed reactor has resulted in 12.4 g/l, when compared to lab scale production of 7.02 g/l and 8.1 g/l under mobilized and immobilized conditions with 20 g/l glucose. The yield/product of lactic acid covered around 4 g/1 irrespective of the sugar (carbon source) concentration. Conclusion: Therefore, the present work establishes the significance of cost effective, autoclavable biofilm based fermentation. Long-standing effectiveness of biofilm in continuous reactors designated that the biofilms are effectively maintained for the conversion of sugars (carbohydrates) to lactic acid mainly.