Day 3 :
Keynote Forum
Ho Nam Chang
KAIST, Korea
Keynote: Techno-economic assessment of microbial lipids based on volatile fatty acids substrate by oleaginous Cryptococcus curvature
Time : 09:30-10:00
Biography:
Ho Nam Chang has completed his PhD from Stanford University in Chemical Engineering (1971). After one year’s postdoctoral studies from Iowa State Univ., he returned to KAIST, Korea in 1976, where he served for 39 years until his retirement in February 2015 (as Professor Emeritus). He has been continuing his work on microbial biodiesel and osmotic pressure using reverse osmosis in Pukyung National and Chungbuk National Universities for successful commercialization of microbial biodiesel from low cost biomass such as food waste. He has published more than 365 papers in reputed journals, 10,290 citations (h-index 56, Google scholar) and has been serving as Advisory Board Member of Biotechnology and Bioengineering, the best journal in Biotechnology (Engineering) area by Wiley-Blackwell.
Abstract:
Techno-economic microbial diesel production were assessed using commercial simulation software (SuperProDesigner, Intelligen.com) in terms of raw material cost, microbial lipid yield over substrate (g/g), lipid content of cells, bioreactor productivity and cost of downstream processing. The simulation shows that glucose is not suitable because of its high cost. Volatile fatty acids (VFAs) derived from low cost biomass were found to be the most suitable substrate since VFAs can be produced at lowest processing cost even from lignocellulosic biomass. For bioreactor productivity multi-stage continuous high cell density culture (MSC-HCDC) was employed, which gives high bioreactor productivity together with product titer. Current experimental product titer of 5 wt% needs to remove about 550 g water from the fermentation broth. Thermal methods require high energy consumption for simple evaporation, in terms of kwh/m3 water removal, 706 and 25 while only 4 or less is needed if osmotic pressure free (Δπ=0) reverse osmosis is used. Also experimental of biolipid production kinetics of oleaginous C. curvature will be presented. At a VFAs cost of 150$/ton (biomass cost, 75$/ton, 50% yield) microbial diesel cost is estimated to be around 1.15$/L and 0$/ton VFAs gives a much lower cost. Further improvement of cells for higher VFAs yield from biomass and microbial lipid yield, and overproduction and secretion of lipids may cut down the cost further.
- Obesity and Health, Plant, Microbial lipids and Essential Oils, Lipids and Bioenergy and Protein-Lipid and Lipid-Lipid Interactions
Chair
Ho Nam Chang
KAIST, Korea
Co-Chair
Emmanuel Mukwevho
North West University, South Africa
Session Introduction
Peña Betancourt S.D.
Autonomous Metropolitan University. Campus Xochimilco, Mexico
Title: Comparision of the lipid content and the fumonisins concentration in maize genetic diversity
Time : 10:00-10:25
Biography:
Peña Betancourt S D is a Master in Science from the National Autonomous University of Mexico, clinical toxicology specialist and PhD from the University of Lyon, France. She is a full time Professor in the Agricultural and Animal Production Department at University Autonomous Metropolitan, campus Xochimilco and Head of the Laboratory of Toxicology. She has published 15 articles in national and international journals. She served as head of the research on quality safety of agricultural products Animal and Agricultural Production Department. She is a Tutor of the Master's and Doctoral programs in divers Institutions of higher education like UNAM, UAM, UAEM and UAZ.
Abstract:
In Mexico, corn is the staple food grain; per capita consumption is estimated at 800 g per day and that 70% of the population suffer from obesity and diabetes type 2. The aim of this study was to determine lipid content and fumonisin in maize genetic diversity, to avoid a potential health risk for high intake of carbohydrates and toxic substances that interfere with lipid metabolism. 25 samples were collected in three states (State of Mexico, Hidalgo and Morelos) at Central Regions in Mexico, (8) landraces were identified, (10) improved corn hybrids and (7) Bt corn, which were subjected to a lipid extraction method Golfisch, AOAC and total fumonisin by ELISA method (Ridascreen Fast Fumonisin). Chemical analysis confirmed a significant increase in total lipid content (8.075%) in Bt with respect to the non-Bt maize hybrids (5.07%). The presence of fumonisin levels was detected in 4 mg kg native and improved corn and 0.56 mg kg in Bt maize. In conclusion, the data showed an increase in total lipids in maize, which expressed a recombinant protein (Cry1Ab) and decreased levels fumonisin, regarding native and improved maize. Fumonisin levels detected may be a risk to consumer health. It is recommended to evaluate the additive effect of excess lipids and fumonisin in the diet of the Mexican population.
Emmanuel Mukwevho
North West University, South Africa
Title: Exercise-induced Calmodulin dependent protein kinase (CaMK)II activation regulates saturated and unsaturated fatty acids in rat skeletal muscle
Time : 10:25-10:50
Biography:
Emmanuel Mukwevho has completed his PhD in 2010 from University of Cape Town, South Africa in Anatomy and Cell Biology. He is an Associate Professor of Biochemistry at North West University, South Africa. He has published both nationally and internationally in reputed journals and his specialiality is in Obesity and Diabetes, where he lead the Diabetes & Obesity Therapeutics Research group at North West University
Abstract:
CaMKII regulates many pathways involved in the regulation of various cellular and molecular mechanisms that result in myriad health benefits. Exercise is a key activator of CaMKII, and shown to improve many functional activities in individuals who exercise compared with those who do not exercise, however the mechanism involved not yet fully elucidated, which became the objective of this study. In this study using rats, we investigated various lipids metabolism for both saturated and non-saturated fatty acids in rats that exercised, non-exercised and exercised+KN93 (CaMKII inhibitor). Lipids were analysed using GC×GC TOFMS. Palmitoleic acid and oleic acid which are monounsaturated fatty acids known to promote insulin sensitivity and improve glycaemic control were investigated. Levels of the exercise group showed ~2.0 fold increase compared with the non-exercise (control) group. Abolishing CaMKII activity by administration of KN93 significantly decreased exercise-induced Palmitoleic acid levels. Oleic acid levels of the exercise group were ~ 4.1 folds higher than the non-exercise group and followed the same pattern as Palmitoleic acid. Lauric acid is a saturated fatty acid, which increases fatty acid needed for better health. The exercise group showed ~ 8.7 fold increase compared with the non-exercise group of Lauric acid. The exercise + KN93 group significantly reduced induction by ~2.5 fold compared with the exercise group. On the other hand, Myristic acid and palmitic acid which are saturated fatty acids known to increase risk factors of metabolic syndrome. The myristic acid level of the exercise group decreased by ~3.4 fold compared with the control group, whereas the exercise + KN93 group significantly increased by ~4.3 compared with the exercise group. In conclusion, CaMKII can reduce the risk factors of metabolic syndrome and type 2 diabetes
Allison W Xu
University of California, San Francisco
Title: Regulation of hypothalamic neuronal function in obesity
Time : 11:10-11:35
Biography:
Allison W Xu completed her PhD at University of Texas - M.D. Anderson Cancer Center and conducted her Postdoctoral studies at Stanford University School of Medicine. Subsequently, she started her independent research program, and she is currently an Associate Professor in the Diabetes Center at University of California, San Francisco. Her laboratory focuses on understanding how hypothalamic neurons sense and respond to peripheral metabolic hormones and how these regulatory circuits regulate food intake, body weight, hepatic lipid and glucose metabolism in normal physiology and obesity
Abstract:
Obesity develops with chronic consumption of palatable energy-dense diets, and also with increasing age. With persistent positive energy balance, the increase in body weight is accompanied by a steady rise in circulating leptin levels, indicating the progressive development of counter regulatory mechanisms to antagonize leptin's anorexigenic effects. Hypothalamic neurons co-expressing agouti-related peptide (AgRP) and neuropeptide Y are direct leptin targets. We have recently shown that AgRP neurons are the predominant cell type situated outside the blood-brain barrier in the mediobasal hypothalamus. AgRP neurons are able to sense slight changes in plasma metabolic signals, such as leptin, but they also more quickly develop cellular leptin resistance in contrast to proopiomelanocortin (POMC) and other hypothalamic neurons that remain leptin-sensitive. AgRP neurons also display age-dependent increase in innervation onto their target neurons, and this process is accelerated by chronic high-fat feeding. Our studies suggest that AgRP neurons are critical sensors for peripheral metabolic hormones and that they play a dynamic role in metabolic fine tuning in response to acute changes in nutritional status. Our studies also suggest that these neurons, with their unique anatomical relationship with the blood-brain barrier, could serve as important targets for therapeutic intervention for the treatment of metabolic disorders
Andromeda Nauli
California Northstate University, USA
Title: Characterization of the newly developed in vitro chylomicron assay and its potential applications
Time : 11:35-12:00
Biography:
Andy Nauli is an Assistant Professor in the California Northstate University. He received his Ph.D. from the University of Cincinnati in 2005. His research interests include dietary fat absorption, chylomicron biogenesis, oral lipophilic drug bioavailability, and red meat allergy. His work has received more than 440 citations and $200,000 in grant funding. He has trained more than 12 students in his laboratory; served as a reviewer for several journals, including JBC, Metabolism, AJP; chair of seed grant committee; reviewer for the American Association of Colleges of Pharmacy grants; and editorial member of several peer-reviewed journals
Abstract:
The small intestine absorbs lipophilic molecules and transports them in triglyceride-rich lipoproteins. We recently developed a cell-based model capable of producing these lipoproteins. The secreted lipoproteins, namely chylomicrons and very low-density lipoproteins, were isolated by NaCl gradient ultracentrifugation. Their triglycerides, apolipoprotein B, and particle size distribution were subsequently analyzed by enzymatic assay, ELISA/Western blot, and transmission electron microscopy, respectively. Our analysis showed that 21% of the total number of secreted lipoproteins were chylomicrons. Most of the chylomicrons had a diameter of 80-200 nm, and they contained both apolipoprotein B-48 and B-100. In addition, we were able to utilize lentivirus expression system, which is more effective than the regular transfection methods, in upregulating gene expression. Our newly developed model/assay can potentially be used to study dietary fat absorption, chylomicron biogenesis, oral lipophilic drug bioavailability, and intestinal transport of lipophilic molecules
Malinna Jusoh
Universiti Malaysia Terengganu, Malaysia
Title: Effects of gibberellin on oil accumulation, fatty acid compositions and expression of fatty acid biosynthetic genes in Chlorella vulgaris (Trebouxiophyceae)
Time : 12:00-12:25
Biography:
Malinna completed her MSc from University of Oxford, United Kingdom in 2010 and PhD last year from Universiti Malaysia Terengganu (UMT), Malaysia. Upon graduation, she works as a lecturer at the School of Fundamental Science, UMT and a junior research fellow at the Institute of Marine Biotechnology, also in UMT. Her research interest is on the fatty acid and oil production of microalgae. She has been working on the gene regulations and manipulation of growth conditions to maximize the production of lipids in microalgae
Abstract:
Gibberellin (GA) is a plant hormone that regulates many physiological processes in plants. In microalgae, GA is synthesized through a slightly different pathway from higher plant GA. Recent studies have shown that several plant hormones such as auxin and jasmonic acid influence microalgae growth and fatty acid accumulation. In this study, the effects of exogenously applied GA were investigated on the growth and total oil content of a marine microalga, Chlorella vulgaris (Trebouxiophyceae) during early stationary growth phase. Results showed that GA gradually increases the cell density of C. vulgaris to up to 42% on days after treatment (DAT)-8 and also capable of delaying the algal senescence. However, the increment in cell density did not enhance the total oil production albeit transient modification of fatty acid compositions was observed for saturated (SFA) and polyunsaturated fatty acid (PUFA). This illustrates that GA only promotes cell division and growth but not the oil accumulation. In addition, application of GA in culture medium was shown to promote transient increment of palmitic (C16:0) and stearic (C18:0) acids from DAT-4 to DAT-6 and this changes is correlated with the expression of β-ketoacyl ACP synthase I (KAS I) gene. This result verified the function of this gene in the fatty acid biosynthesis pathway to produce C16:0 fatty acid
Ifeanyichukwu Edeh
University of Birmingham, UK
Title: Application of face centered central composite design in optimization of subcritical water mediated extraction of lipid from activated sludge
Time : 12:25-12:50
Biography:
Ifeanyichukwu is a Lecturer at the University of Port Harcourt, Nigeria. He is a Petroleum Technology Development Fund (PTDF) Ph.D Scholar and a member of the Supercritical Fluid Technology Group at the University of Birmingham, United Kingdom. His research interest is in the area of using state-of-art technology to produce bioenergy from waste materials. He is almost completing a research work on “A Critical Evaluation of Utility of Subcritical Water to Support the Production of Biodiesel and Renewable Diesel from Lipid Fraction of Activated Sludge” at the University of Birmingham. He has published many papers in reputable Journals
Abstract:
Bioenergy such as biodiesel and renewable diesel can be produced from lipid extracted from a microbial biomass known as activated sludge. At the moment, low lipid yield from activated sludge compared to cooking oil and animal fat seems to affect its application in bioenergy production. There is need to find an optimization technique and extraction method which has the capacity to increase the lipid yield. In this study, subcritical water was used to break the cellular structure of activated sludge in order to release its lipid content. Face centered central composite response surface design was used to optimize lipid yield. The biomass was recovered from activated sludge slurry collected from a sewage treatment work in the UK. Subcritical water mediated extraction using activated sludge was carried out in a semi batch reactor, after which lipids were extracted from the products recovered. Lipids were characterized by high temperature gas chromatography using authentic standards. Statistical analysis of face centered central composite response surface suggested a quadratic model with R-squared 0.9444. The analysis of variance (ANOVA) showed that the model was significant and lack of fit was insignificant. The lipids from the extraction products showed a variation in the profile obtained. The maximum lipid yield 41% was obtained at the optimum conditions of temperature 80oC, time 20 min and biomass loading 1%. The lipid yield when compared to that obtained from solvent extraction without subcritical water treatment and optimization was almost seven times higher, thus offering a greater potential for renewable bioenergy production