Read by QxMD icon Read


Nianci Shi, Weian Mao, Xiaoxia He, Zhe Chi, Zhenming Chi, Guanglei Liu
Yarrowia lipolytica is a promising platform for the single cell oil (SCO) production. In this study, a transformant X+N8 in which exo- and endo-inulinase genes were co-expressed could produce an inulinase activity of 124.33 U/mL within 72 h. However, the inulinase activity of a transformant X2 carrying a single exo-inulinase gene was only 47.33 U/mL within 72 h. Moreover, the transformant X+N8 could accumulate 48.13% (w/w) SCO from inulin and the cell dry weight reached 13.63 g/L within 78 h, which were significantly higher than those of the transformant X2 (41...
November 18, 2017: Applied Biochemistry and Biotechnology
Seunghyun Ryu, Cong T Trinh
Pentoses including xylose and arabinose are the second-most prevalent sugars of lignocellulosic biomass that can be harnessed for biological conversion. Although Yarrowia lipolytica has emerged as a promising industrial microorganism for production of high-value chemicals and biofuels, its native pentose metabolism is poorly understood. Our previous study demonstrated that Y. lipolytica (ATCC MYA-2613) has endogenous enzymes for D-xylose assimilation, but inefficient xylitol dehydrogenase causes Y. lipolytica to assimilate xylose poorly...
November 17, 2017: Applied and Environmental Microbiology
Allison Yaguchi, Alana Robinson, Erin Mihealsick, Mark Blenner
BACKGROUND: The oleaginous yeast, Trichosporon oleaginosus, has been extensively studied for its ability to metabolize non-conventional feedstocks. These include phenol-containing waste streams, such as distillery wastewater, or streams consisting of non-conventional sugars, such as hydrolyzed biomass and various bagasse. An initial BLAST search suggests this yeast has putative aromatic metabolizing genes. Given the desirability to valorize underutilized feedstocks such as lignin, we investigated the ability of T...
November 17, 2017: Microbial Cell Factories
Gergely Kosa, Volha Shapaval, Achim Kohler, Boris Zimmermann
BACKGROUND: Analyses of substrate and metabolites are often bottleneck activities in high-throughput screening of microbial bioprocesses. We have assessed Fourier transform infrared spectroscopy (FTIR), in combination with high throughput micro-bioreactors and multivariate statistical analyses, for analysis of metabolites in high-throughput screening of microbial bioprocesses. In our previous study, we have demonstrated that high-throughput (HTS) FTIR can be used for estimating content and composition of intracellular metabolites, namely triglyceride accumulation in oleaginous filamentous fungi...
November 13, 2017: Microbial Cell Factories
Yong-Su Jin, Jamie Hd Cate
Production of biofuels from lignocellulosic biomass remains an unsolved challenge in industrial biotechnology. Efforts to use yeast for conversion face the question of which host organism to use, counterbalancing the ease of genetic manipulation with the promise of robust industrial phenotypes. Saccharomyces cerevisiae remains the premier host for metabolic engineering of biofuel pathways, due to its many genetic, systems and synthetic biology tools. Numerous engineering strategies for expanding substrate ranges and diversifying products of S...
November 8, 2017: Current Opinion in Chemical Biology
Sujit Sadashiv Jagtap, Christopher V Rao
The sugar alcohol D-arabitol is one of the Department of Energy's top twelve bio-based building block chemicals. In this study, we found that the oleaginous yeast Rhodosporidium toruloides IFO0880 produces D-arabitol during growth on xylose in nitrogen-rich medium. Efficient xylose utilization was a prerequisite for extracellular D-arabitol production. During growth in complex media, R. toruloides produced 22 ± 2, 32 ± 2, and 49 ± 2 g/L D-arabitol from 70, 105, and 150 g/L xylose, respectively. In addition, we found that R...
November 11, 2017: Applied Microbiology and Biotechnology
Maria Athenaki, Chryssavgi Gardeli, Panagiota Diamantopoulou, Sidoine Sadjeu Tchakouteu, Dimitris Sarris, Antonios Philippoussis, Seraphim Papanikolaou
The last years there has been a significant rise in the number of publications in the international literature that deal with the production lipids by microbial sources (the "single cell oils; SCOs" that are produced by the so-called "oleaginous" microorganisms). In the first part of the present review-article, a general overview of the oleaginous microorganisms (mostly yeasts, algae and fungi) and their potential upon the production of SCOs is presented. Thereafter, physiological and kinetic events related with the production of, mostly, yeast and fungal lipids when sugars and related substrates like polysaccharides, glycerol, etc (the "de novo" lipid accumulation process) or hydrophobic substrates like oils and fats (the "ex novo" lipid accumulation process) were employed as microbial carbon sources, are presented and critically discussed...
November 8, 2017: Journal of Applied Microbiology
Yi Xin, Yandu Lu, Yi-Ying Lee, Li Wei, Jing Jia, Qintao Wang, Dongmei Wang, Fali Bai, Hanhua Hu, Qiang Hu, Jin Liu, Yantao Li, Jian Xu
Microalgal oils, depending on their degree of unsaturation, can be utilized as either nutritional supplements or fuels, thus a feedstock with genetically designed and tunable degree of unsaturation is desirable to maximize process efficiency and product versatility. Systematic profiling of ex vivo (in yeast), in vitro and in vivo activities of type II diacylglycerol acyltransferases in Nannochloropsis oceanica (NoDGAT2s or NoDGTTs), via reverse genetics, revealed that NoDGAT2A prefers saturated fatty acids (SFAs), 2D prefers monounsaturated fatty acids (MUFAs) and 2C exhibits the strongest activity for polyunsaturated fatty acids (PUFAs)...
October 26, 2017: Molecular Plant
Iwona Gientka, Marek Kieliszek, Karolina Jermacz, Stanisław Błażejak
The search for efficient oleaginous microorganisms, which can be an alternative to fossil fuels and biofuels obtained from oilseed crops, has been going on for many years. The suitability of microorganisms in this regard is determined by their ability to biosynthesize lipids with preferred fatty acid profile along with the concurrent utilization of energy-rich industrial waste. In this study, we isolated, characterized, and identified kefir yeast strains using molecular biology techniques. The yeast isolates identified were Candida inconspicua, Debaryomyces hansenii, Kluyveromyces marxianus, Kazachstania unispora, and Zygotorulaspora florentina...
2017: BioMed Research International
Ruiling Gao, Zifu Li, Xiaoqin Zhou, Shikun Cheng, Lei Zheng
Background: The sustainability of microbial lipids production from traditional carbon sources, such as glucose or glycerol, is problematic given the high price of raw materials. Considerable efforts have been directed to minimize the cost and find new alternative carbon sources. Volatile fatty acids (VFAs) are especially attractive raw materials, because they can be produced from a variety of organic wastes fermentation. Therefore, the use of volatile fatty acids as carbon sources seems to be a feasible strategy for cost-effective microbial lipid production...
2017: Biotechnology for Biofuels
Dongming Xie
As one of the major biofuels to replace fossil fuel, biodiesel has now attracted more and more attention due to its advantages in higher energy density and overall less greenhouse gas generation. Biodiesel (fatty acid alkyl esters) is produced by chemically or enzymatically catalyzed transesterification of lipids from microbial cells, microalgae, oil crops, or animal fats. Currently, plant oils or waste cooking oils/fats remain the major source for biodiesel production via enzymatic route, but the production capacity is limited either by the uncertain supplement of plant oils or by the low or inconsistent quality of waste oils/fats...
2017: Frontiers in Bioengineering and Biotechnology
Bonnie A McNeil, David T Stuart
The oleaginous yeast Lipomyces starkeyi was engineered for the production of long-chain fatty alcohols by expressing a fatty acyl-CoA reductase, mFAR1, from Mus musculus. The optimal conditions for production of fatty alcohols by this strain were investigated. Increased carbon-to-nitrogen ratios led to efficient C16 and C18 fatty alcohol production from glucose, xylose and glycerol. Batch cultivation resulted in a titer of 1.7 g/L fatty alcohol from glucose which represents a yield of 28 mg of fatty alcohols per gram of glucose...
October 26, 2017: Journal of Industrial Microbiology & Biotechnology
Martín A Hernández, Gerd Gleixner, Dirk Sachse, Héctor M Alvarez
Nitrogen lipid regulator (NlpR) is a pleiotropic regulator that positively controls genes associated with both nitrogen and lipid metabolism in the oleaginous bacterium Rhodococcus jostii RHA1. In this study, we investigated the effect of nlpR disruption and overexpression on the assimilation of (13)C-labeled glucose as carbon source, during cultivation of cells under nitrogen-limiting and nitrogen-rich conditions, respectively. Label incorporation into the total lipid extract (TLE) fraction was about 30% lower in the mutant strain in comparison with the wild type strain under low-nitrogen conditions...
2017: Frontiers in Microbiology
Felix Bracharz, Teun Beukhout, Norbert Mehlmer, Thomas Brück
Cutaneotrichosporon oleaginosus ATCC 20509, previously known as Trichosporon oleaginosus, Cryptococcus curvatus, Apiotrichum curvatum or Candida curvata D is an oleaginous yeast with several favorable qualities: it is fast growing, accumulates high amounts of lipid and has a very broad substrate spectrum. Its resistance to hydrolysis byproducts and genetic accessibility make it a promising cell factory for custom tailored microbial oils. However, literature about this organism is of varying degree of quality...
October 25, 2017: Microbial Cell Factories
Gouri Katre, Namasvi Ajmera, Smita Zinjarde, Ameeta RaviKumar
BACKGROUND: Oleaginous yeasts are fast emerging as a possible feedstock for biodiesel production. Yarrowia lipolytica, a model oleaginous yeast is known to utilize a variety of hydrophobic substrates for lipid accumulation including waste cooking oil (WCO). Approaches to increase lipid content in this yeast include metabolic engineering which requires manipulation of multiple genes in the lipid biosynthesis pathway. A classical and cost-effective approach, namely, random chemical mutagenesis on the yeast can lead to increased production of biodiesel as is explored here...
October 24, 2017: Microbial Cell Factories
Guangyuan Wang, Delong Li, Zhengang Miao, Shanshan Zhang, Wenxing Liang, Lin Liu
Yarrowia lipolytica is considered as a promising microbial cell factory for bio-oil production due to its ability to accumulate a large amount of lipid. However, the regulation of lipid metabolism in this oleaginous yeast is elusive. In this study, the MHY1 gene was disrupted, and 43.1% (w/w) intracellular oil based on cell dry weight was obtained from the disruptant M-MHY1, while only 30.2% (w/w) lipid based on cell dry weight was obtained from the reference strain. RNA-seq was then performed to analyze transcriptional changes during lipid biosynthesis after MHY1 gene inactivation...
October 18, 2017: Biochimica et Biophysica Acta
Irnayuli R Sitepu, Luis A Garay, Lauren Enriquez, Russell Fry, John H Butler, Julian M Lopez, Atit Kanti, Sarah A Faulina, Agustinus J Nugroho, Blake A Simmons, Steven W Singer, Christopher W Simmons, Kyria Boundy-Mills
Pretreatment with ionic liquids (IL) such as 1-ethyl-3-methylimidazolium chloride or acetate is an effective method for aiding deconstruction of lignocellulosic biomass; however, the residual IL remaining in hydrolysates can be inhibitory to growth of ethanologenic or oleaginous yeasts that have been examined in the literature. The aim of this study was to identify oleaginous yeasts that are tolerant of the IL [C2C1Im][OAc] and [C2C1Im]Cl using 45 strains belonging to 38 taxonomically diverse species within phyla Ascomycota and Basidiomycota...
December 2017: Applied Microbiology and Biotechnology
Ling Xia, Rong Huang, Yinta Li, Shaoxian Song
The effects of growth phase on the lipid content and surface properties of oleaginous microalgae Botryococcus sp. FACGB-762, Chlorella sp. XJ-445 and Desmodesmus bijugatus XJ-231 were investigated in this study. The results showed that throughout the growth phases, the lipid content of microalgae increased. The surface properties like particle size, the degree of hydrophobicity, and the total concentration of functional groups increased while net surface zeta potential decreased. The results suggested that the growth stage had significant influence not only on the lipid content but also on the surface characteristics...
2017: PloS One
Farha Deeba, Alok Patel, Neha Arora, Vikas Pruthi, Parul A Pruthi, Yuvraj S Negi
The potential of lipid accumulation by oleaginous yeast Cryptococcus vishniaccii grown on amaranth seed aqueous extract (AAE) media was assessed. Maximum cell biomass productivity of 104 mg/L/h, lipid productivity of 54 mg/L/h, and lipid content of 52.31% were recorded on AAE when carbon to nitrogen (C:N) ratio increased from 134 to 147 after removal of ammonia nitrogen. The lipid droplet (LD) size (2.32 ± 0.38 μm) was visualized by fluorescence microscopy using Nile red stain indicating maximum accumulated triacylglycerol (TAG) at C:N 147...
October 16, 2017: Environmental Science and Pollution Research International
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"