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Microbial lipolytic enzymes e promising energy-efficient biocatalysts in bioremediation
آنزیم های میکروبی لیپولیتیک و نوید دهنده بیوکاتالیزورها با صرفه جویی در مصرف انرژی در زیست هسته ای-2020 Enzymes are biological catalysts that significantly speed up reactions by lowering their activation energy.
Compared to chemical catalysts, enzymatic reactions take place in milder temperature conditions. The
wide range of advantageous catalytic properties has enabled the use of enzymes in different fields of
biotechnology. Microbial lipolytic enzymes have gained attention for the ability to catalyse biotransformation
reactions of different esters-bond containing compounds. Conversion of the latter into highenergy
products like biofuel and other value-added products (fatty acid esters, mono- and diacylglycerols,
etc.) via energy-efficient and ecologically-friendly way makes these biocatalysts an important
tool for sustainable biotechnology. However, the role of lipolytic enzymes in the waste management was
not being well explored. This review highlighted some important aspects and strategies of lipolytic
enzyme-mediated bioremediation to detoxify the lipid, plastic, pesticide and other environmental waste
combined with production of important industrial compounds via less energy consuming way. Future
perspectives of microbial lipolytic biocatalysts in environmental safety and energy saving are discussed
herein as well. Keywords: Lipase | Environmental pollution | Esterification | Degradation of biopolymers | Energy management |
مقاله انگلیسی |
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Extender osmolality, glycerol and egg yolk on the cryopreservation of epididymal spermatozoa for gamete banking of the Cantabric Chamois (Rupicapra pyrenaica parva)
Extender osmolality, glycerol and egg yolk on the cryopreservation of epididymal spermatozoa for gamete banking of the Cantabric Chamois (Rupicapra pyrenaica parva)-2019 Germplasm banking is a key technology enabling the ex-situ conservation of wild species. However, cryopreservation protocols must be tested to assure the applicability of the banked material. The objective of this study was defining a range of parameters for the composition of a semen extender for Cantabrian chamois epididymal spermatozoa (post-mortem collection). The freezing extender was based in a TES-Tris-fructose buffer, modifying its composition in three experiments: Osmolality of the buffer (320, 380 or 430 mOsm/kg, 8% glycerol, 15% egg yolk), glycerol (4 or 8%, 430 mOsm/kg, 15% egg yolk), egg yolk (10 or 15%, 430 mOsm/kg, 4% glycerol). Sperm was extended at 100 mill. spermatozoa/ml, cooled at 5 ○ C and frozen at —20 ○ C/min. Sperm quality was assessed pre and post-thawing (CASA, HOS test, abnormal forms, cytoplasmic droplets, and viability and acrosomal damage by flow cytometry). Freez- ability was good overall, with total motility of 65.5% ± 2.4 initial and 55.8% ± 2.4 post-thawing. The ex- tenders affected the post-thaw sperm quality marginally. Whereas osmolalities and glycerol concentrations seemed not to differ, 430 mOsm/kg and 4% glycerol might be preferred. Egg yolk con- centrations only differed on sperm velocity (VCL: 84.0 ± 6.7 mm/s in 10% vs. 70.7 ± 6.2 mm/s in 15%, P < 0.05). Our results suggest a good cryotolerance of chamois epididymal spermatozoa, with a preferred extender composition of hyperosmotic buffer, glycerol in the 4% range and lower egg yolk (10% range) than other ruminants.© 2018 Elsevier Inc. All rights reserved. Keywords : Cantabrian chamois | Cryopreservation | Epididymal spermatozoa | Extender | Osmolality | Glycerol |
مقاله انگلیسی |