Conversion of carbohydrates to lipids at high yield and productivity is essential for cost-effective production of renewable biodiesel. Although some microorganisms can convert sugars to oils, conversion yields and rates are typically low due primarily to allosteric inhibition of the lipid biosynthetic pathway by saturated fatty acids. By reverse engineering the mammalian cellular obese phenotypes, we identified the delta-9 stearoyl-CoA desaturase (SCD) as a rate limiting step and target for the metabolic engineering of the lipid synthesis pathway in Yarrowia lipolytica. Simultaneous overexpression of SCD, Acetyl-CoA carboxylase (ACC1), and Diacylglyceride acyl-transferase (DGA1) in Y. lipolytica yielded an engineered strain exhibiting highly desirable phenotypes of fast cell growth and lipid overproduction including high carbon to lipid conversion yield (84.7% of theoretical maximal yield), high lipid titers (~55g/L), enhanced tolerance to glucose and cellulose-derived sugars. Moreover, the engineered strain featured a three-fold growth advantage over the wild type strain. As a result, a maximal lipid productivity of ~1g/L/h is obtained during the stationary phase. Furthermore, we showed that the engineered yeast required cytoskeleton remodeling in eliciting the obesity phenotype. Altogether, our work describes the development of a microbial catalyst with the highest reported lipid yield, titer and productivity to date. This is an important step towards the development of an efficient and cost-effective process for biodiesel production from renewable resources.

No abstract

No abstract

Gene expression analyses to study the development of cotton fibers require high-quality nucleic acid. The conventional methods of nucleic acid extraction results in sub-quality nucleic acids with low yields. Young fibers are rich in polyphenols and sugars that react with nucleic acid to form phenols and insoluble substances. Furthermore, mature fibers contain more than 95% cellulose, hindering the nucleic acid isolation. Cytoplasm collapse and cellulose deposition also result in a very low yield of nucleic acid. Three different methods of RNA isolation from different cotton tissues were compared in this study to determine the best and most efficient one. The integrity and quality of RNA were analyzed using UV spectrum, agarose gel electrophoresis, RIN values, PCR, and Northern blot hybridization. RNA of functional quality was observed when using the high ion and pH method, with an A260/A280 ratio up to 1.87 and an average yield of 0.68 mg g-1 from fiber cells. From leaves, we found an A260/A280 ratio of 2.02 and an average yield of 6.35 mg g-1, which is suitable for molecular biology experiments. The extraction buffer with a high ion density and pH value include Tris-HCl, LiCl, EDTA, SDS, sodium deoxycholate, Nonident P-40, mercaptoethanol, and PVP. The addition of sodium deoxycholate and Nonider-40 (NP-40) enhances the density of other salt compounds and elevates the pH value. The results depicted that the high ion and pH method is a simple and effective way to extract a copious amount of high-quality RNA from polysaccharide-rich tissues. This method is also suitable for the extraction of cotton genomic DNA with high purity. Genomic DNA extracted from cotton using this method showed an A260/A230 ratio up to 2.09 and a yield of 1.44 mg g-1. This method is useful for isolating DNA and RNA from cotton fibers and produces high yields and quality at a comparatively low cost.

The study of magnetic nanoparticles (MNPs) is an emergent field of science in this era due to their widespread utilization in the various fields of biomedical science. Developing concerns of magnetic nanoparticles in the researcher’s field led to design a huge number of MNPs including individual or binary metallic particles, oxides, (ferrites), biopolymer coated composites, metallic carbides and graphene mediated nanoparticles. Numerous synthetic routes are defined in literature to attain the desired size, crystal structure, morphology and magnetic properties. To build up biocompatibility, MNPs subjected to surface treatments by coating with some suitable organic or inorganic biomaterials which not only improves its physical characteristics but also elevate its chemical stability. These biomaterials coat either isolatly or in a combined state to enhance the colloidal stability, magnetic properties as well as prevent it cytotoxicity and surface corrosion in the biological media. These properties are essential for the particles and empowering their effectiveness in various biomedical science i.e., drug delivery Magnetic resonance imaging (MRI), hyperthermia, biosensors and gene therapy etc. Current review recapitulates the verdicts of previous research on the subject of magnetic nanoparticles. It will also explain the recent advancements of biomaterials that execute a dynamic role in various medical treatments. Our main focus is to report the particle types, design and properties as well as discussing various synthetic routes including sol gel, co-precipitation, microemulsion, green synthesis, sonochemical method and polyol synthesis etc. These methods produced particles of excellent yield with unique magnetic properties, coercivity and crystallinity and enhanced biocompatibility as compared to traditional methods used to develop MNPs.