Oleaginous Biomass Research Articles

Controlled crushing device-intensified direct biodiesel production of Black Soldier Fly larvae

Insect larvae contain sufficient oil comparable with oleaginous biomass, and hence have potency as alternative biodiesel resources. The direct transesterification of Black Soldier Fly (BSF) larvae have conducted using a controllable crushing device (CCD) and a homogeneous base as a catalyst. The effect of catalyst concentration (wt.%), ratio BSF larvae to methanol (wt./v), reaction time (min) and rotational speed (rpm) on biodiesel conversion was determined. The maximum conversion of 93.8% was achieved at room temperature after 20 min of reaction time and ratio larvae to methanol of 1:2 (wt./v), catalyst concentration of 7 wt% and rotational speed of 3000 rpm. In addition, the green metrics calculation showed that this method produces less waste and uses less solvent. Some of the BSF-biodiesel properties meet the biodiesel standard. The CCD-intensified the DT of BSF larvae is a promising alternative for green and energy-saved biodiesel production.

Bioconversion of agro-industrial by-products into microbial lipids and bioemulsifier by Absidia cylindrospora var. cylindrospora UCP 1301

Large amounts of agro-industrial by-products and wastes are generated in Brazil annually. Often, they are underutilized and improperly disposed, causing environmental pollution. In this context, reuse them as raw material to obtain high-added value products, becomes a promising strategy. Hence, this study aimed to investigate the biotechnological potential of the Mucoralean fungus Absidia cylindrospora UCP 1301 for production of oleaginous biomass and bioemulsifier (BE), using agro-industrial by-products as low-cost substrates. Firstly, the morphological identification of the strain was performed for confirmation. Then, fermentations were carried out, according to a 2³ full-factorial design (FFD) in order to evaluate the influence of substrates concentrations on production of biomass, total lipids and BE. The fungus was identified as Absidia cylindrospora var. cylindrospora and the results showed it as an oleaginous microorganism, since it accumulated lipids above 20 % of dry weight. The highest biomass production (11.38 g/L) was found in condition 3 of the FFD, while the highest lipid yield (32.22%) was reached in assay 6. Moreover, this strain was confirmed as a promising BE-producing microorganism, because of it achieved EI24 values above 50% in all conditions of the FFD. The highest EI24 with motor oil (93.3%) was obtained in condition 7 and this emulsion remained stable after 150 days of incubation. Statistical analysis showed that the three agro-industrial by-products had a significant influence on the production of biomass, lipids and BE, confirming the suitability of unconventional substrates for obtaining both microbial oil and emulsifier, which makes this bioprocess attractive for several industries.

New value from food and industrial wastes – Bioaccumulation of omega-3 fatty acids from an oleaginous microbial biomass paired with a brewery by-product using black soldier fly (Hermetia illucens) larvae

Research on bioconversion based on insects is intensifying as it addresses the problem of reducing and reusing food and industrial waste. To reach this goal, we need to find more means of pairing waste to insects. With this goal, brewers’ spent grains (BSG) - a food waste of the brewing industry - paired with the oleaginous biomass of the thraustochytrid Schizochytrium limacinum cultivated on crude glycerol - a major waste of biodiesel production - were successfully used to grow Hermetia illucens larvae. Combining BSG and S. limacinum in the diet in an attempt to design the lipid profile of H. illucens larvae to contain a higher percentage of omega-3 fatty acids is novel. Insect larvae were grown on three different substrates: i) standard diet for Diptera (SD), ii) BSG, and iii) BSG + 10% S. limacinum biomass. The larvae and substrates were analyzed for fatty acid composition and larval growth was measured until 25% of insects reached the prepupal stage. Our data showed that including omega-3-rich S. limacinum biomass in the BSG substrate promoted an increase in larval weight compared to larvae fed on SD or BSG substrates. Furthermore, it was possible, albeit in a limited way, to incorporate omega-3 fatty acids, principally docosahexaenoic acid (DHA) from BSG + S. limacinum substrate containing 20% of DHA into the larval fat (7% DHA). However, H. illucens with this level of DHA may not be suitable if the aim is to get larvae with high omega-3 lipids to feed carnivorous fish.

Use of Fungal Mycelium as Biosupport in the Formation of Lichen-like Structure: Recovery of Algal Grown in Sugarcane Molasses for Lipid Accumulation and Balanced Fatty Acid Profile.

In this study, a lichen-like structure was obtained through the production of a unique biomass, formed by algae cells of Scenedesmus obliquus adhering to the mycelium of filamentous fungal Mucor circinelloides. This structure was composed in two steps; in the first one, microalgal cells and spores were incubated separately, and in the second one, after 72 h of growth, isolated, mature mycelium was harvested and added to cell culture. For spores’ incubation, a culture medium containing only 2 g·L−1 of glucose and minerals was used. This culture medium, with low sugar content, provided a fungal biomass to the anchorage of microalgae cells. WC medium was used without and with sugarcane molasses supplementation for microalgae cells’ incubation. The lichen-type structure that was formed resulted in 99.7% efficiency in the recovery of microalgae cells and in up to 80% efficiency in the recovery of algae biomass in the lichen biomass composition. In addition, the resulting consortium attained a satisfactory lipid accumulation value (38.2 wt%) with a balanced fatty acid composition of 52.7% saturated plus monounsaturated fatty acids and 47.4% polyunsaturated fatty acids. Since fungal species are easy to recover, unlike microalgae, the lichen-like structure produced indicates an efficient low-cost bioremediation and harvesting alternative; in addition, it provides an oleaginous biomass for various industrial applications.

Promoting hydrocarbon production from fatty acid pyrolysis using transition metal or phosphorus modified Al-MCM-41 catalyst

Oleaginous biomass conversion to liquid hydrocarbon biofuels has emerged as an effective solution to the energy crisis and environmental problems. In this process, the removal of oxygenated compounds will directly affect the effectiveness of subsequent biofuel applications. Herein, deoxygenation of oleic acid by catalytic cracking was conducted using five various elements (La, Ni, P, Zr and Ce) modified Al-MCM-41. The related characterizations were carried out for these catalysts, including N2 physisorption, XRD, XPS, pyridine-FTIR and NH3-TPD techniques. The results showed the mesoporous structure of Al-MCM-41 was maintained after different modifications, and these catalysts greatly improved the hydrocarbons content and physiochemical properties of biofuels. The modified catalysts tended to facilitate the decarbonylation pathway and showed high selectivity to alkane and aromatic hydrocarbons. Besides, La/Al-MCM-41 presented excellent anti-coking activity. Ni/Al-MCM-41 showed both high dehydrogenation and deoxygenation activities. The Zr modification and Ce modification had a promotion effect in the deoxidizing activity of the catalyst, owing to the formation of oxophilic metal oxides. Noteworthily, P/Al-MCM-41 displayed the best deoxidizing performance due to its high Brönsted acidity, which caused the highest hydrocarbons content (82.30 %) and the lowest fatty acids content (around 0 %) of the biofuel. Moreover, the resulting biofuel had not only low oxygen content (3.88 wt.%) and acid value (5.47 mgKOH g−1) but also a high calorific value (44.50 MJ kg−1), which could be processed into green diesel. Hence, the catalytic cracking of fatty acid over P/Al-MCM-41 has excellent potential to produce high-quality renewable fuels.

Increase in lipid productivity and photosynthetic activities during distillery wastewater decolorization by Chlorella vulgaris cultures

Finding an eco-friendly process for the decolorization of distillery wastewaters is a major concern. This study shows that the Chlorella vulgaris CCAP 211/19 strain can be used for color removal and direct production of oleaginous biomass. A response surface method was used for determining optimal operating conditions, including the dilution factor of industrial wastewater. The highest daily light supply values were the most efficient for color removal. The analysis of the microalgae physiological status confirmed that these colored waters could have a photoprotective action. Moreover, the increase in photosystem 2 activities of C. vulgaris CCAP 211/19 strain after short-term incubations in the presence of a synthetic melanoidin confirmed that this fraction is involved in the enhancement of lipid-enriched biomass production. The results show for the first time the stimulation effect of a melanoidin fraction on the lipid content and productivity by C. vulgaris. These results suggest that this approach may be used to design a closed loop, including water and CO2 recycling for the wastewater dilution and photosynthetic carbon fixation, respectively, while providing biomass for useful renewable algae-based feedstocks of potential interest for a distillery process. KEY POINTS: • Chlorella vulgaris cultures can be used for decolorization of distillery wastewaters. • Diluted distillery wastewaters stimulate biomass and lipid productivities. • Melanoidins, as well as distillery wastewater, stimulate photosynthetic activities.

Non-isothermal decomposition kinetics of lipids recovered from oleaginous microbial biomass (C. vulgaris and L. starkeyi): reaction mechanism and TGA-MS analysis

Oleaginous microorganisms and the thermal decomposition of their recovered lipids are new attractive research fields for the sustainable production of biofuels from actual biomass. In this work, the thermal decomposition of lipids from C. vulgaris and from L. starkeyi was investigated using a thermogravimetric analyzer coupled to a mass spectrometer (TGA-MS) under non-isothermal conditions. Thermal decomposition was examined using the one-step reaction model. Integral, differential, and advanced isoconversional methods were implemented to analyze the conversion-dependent activation energy. The Friedman method resulted in an accurate and reliable estimation of the kinetic parameters. The activation energy showed a strong dependence on conversion from 123.5 to 246 kJ mol-1 for lipids from C. vulgaris and from 80.3 to 299.9 kJ mol-1 for lipids from L. starkeyi. The generalized master plot approach evidenced that the thermal decomposition of lipids from C. vulgaris proceeds via three-dimensional diffusion (D3—Jander’s equation). Also, the kinetic analysis indicated that Valensi’s equation (D2), controlled by a two-dimensional diffusion model, is the most likely mechanism for the thermal decomposition of lipids from L. starkeyi. The rate parameters were evaluated via a kinetic compensation plot. Ion temperature evolution was investigated by TGA-MS revealing many of the functional groups evolved in the range of 350–500 °C as C1–C7 aliphatic hydrocarbons, aromatic hydrocarbons, aldehydes, carboxylic acids, and furan derivatives. All these aspects favor the lipid biosynthesis from microbial biomass to potential lipid-based building blocks.

Predictive capability evaluation and optimization of sustainable biodiesel production from oleaginous biomass grown on pulp and paper industrial wastewater

Biodiesel, as a green fuel, acts as a potential candidate to supplement conventional fossil fuels. This research study targets green environment (using biodiesel) and clean environment (reduce wastewater) by producing biodiesel through oleaginous biomasses (Yarrowia lipolytica, Metschnikowia pulcherrima and Lipomyces starkeyi) grown on pulp and paper industrial wastewater. Batch culture studies were explored for the potential feedstock of the oleaginous organism by the synthesis of single cell oil and fatty acid methyl ester (FAME) yield. Response surface methodology (RSM) was used to design the optimal experimental matrix and identify the optimal process conditions that enhance the FAME yield. To determine the inherent characteristics of the growth of oleaginous biomasses on the industrial wastewater, a data-driven adaptive neuro-fuzzy inference system (ANFIS) is implemented. Y. lipolytica strain cultured shown high biomass concentration of 32.36 g/l with biomass productivity of 5.39 g/l/d was considered for further scale-up for the transesterification process. Results indicated that the maximum yield of 0.48 (g-biodiesel/g-lipid) was obtained under the 2.5 g of lipid dosage with 0.02 g/ml of catalyst concentration by constant stirring at 70 °C. The optimum conditions to achieve maximum FAME yield of 1.154 g/g was obtained at 2.485 g, 70.87 °C and 0.021 g/ml for lipid dosage, temperature and catalyst concentrations, respectively.

Optimization of bio-oil production from Pistacia lentiscus seed liquefaction and its effect on diesel engine performance and pollutant emissions

The development of biofuels from oleaginous biomass has attracted a great deal of interest not only because of the environment pollution but also because of the rapid depletion of the fossil fuel reserves. Among the biomass conversion processes, the solvolysis reaction has shown to be an interesting solution which allows the direct conversion of raw materials into biofuel. In the present work, a solvolysis process is applied on Pistacia lentiscus (PL) seeds using ethanol as solvent for bio-oil production. Several temperatures varying from 270 to 330 °C, reaction time in the range 15–45 min and ethanol:PL seed ratio values from 0.5–1.5 ml/g were considered. The response surface methodology (RSM) combined with Box-Behnken design (BBD) is used for modeling and optimizing both the process yield and bio-oil viscosity. The results show that the optimum conditions are obtained for a reaction temperature of 304.91 °C, a reaction time of 35.24 min, and an ethanol:PL seed ratio of 1.16. Under these conditions, the predicted PL bio-oil yield is around 63.5% with a bio-oil viscosity of 5.88 mm2/s. The PL bio-oil physicochemical properties showed a good agreement with those of diesel fuel and in conformity with the international requirements except for the viscosity, whose value was found to be slightly higher than the standard. The engine tests show that the fuel specific consumption increases around 9% with a mixture containing bio-oil up to 30%. On the other hand, slight increases in CO (13%), HC (25%) and particulate (30%) emissions were recorded.

Single cell oil production and modification for fuel and food applications: Assessing the potential of sugarcane molasses as culture medium for filamentous fungus

Sugarcane molasses (SM) a low-cost substrate was used for single-cell oil production by Mucor circinelloides. Cultivations were carried out with diluted molasses at a concentration of 40 g sugars L−1 with and without nutrients supplementation. The best performance in regard to the lipid productivity (0.66 g L−1 day−1), biomass (11.2 g L−1) and lipid content (29 wt.%) was attained in a medium containing SM supplemented with minor nutrients. The profile of fatty acid composition revealed suitable properties for biodiesel synthesis, although high levels of polyunsaturated fatty acids (PUFA) were also found, which may suggest the possibility of using the oleaginous biomass from Mucor circinelloides URM 4182 as feedstock to yield both products. Concentrated solutions of polyunsaturated fatty acids (PUFA) were obtained by enzymatic hydrolysis of the acylglycerol structures, while biodiesel was prepared by direct transesterification of the oleaginous biomass using acid heterogeneous catalyst.

Quantification of Lipid Content in Oleaginous Biomass Using Thermogravimetry.

Laboratory analytical techniques employed for triglyceride quantification in oleaginous biomass (e.g., microalgaeand oilseeds) involve multiple steps and typically require use of volatile organic solvents. Here we describe a single-step approach for measurement of triglycerides using thermogravimetry (TG). We have observed that triglycerides undergo complete volatilization over a narrow temperature interval of 370-450°C, with negligible solid residue under inert atmosphere, whereas other constituents of oleaginous biomass (such as proteins and carbohydrates) primarily degrade below 350°C. As a result, triglyceride content of biomass can be estimated using TG by determining the mass loss of the sample in the temperature interval of 370-450°C.

A Data Envelopment Analysis Method for Location Optimization of Microalgae Cultivation: A Case Study

Environmental issues and depletion of fossil energy resources have triggered a sense among and practitioners to seek the ways of substituting fossil energy resources with renewable ones. Biodiesel is a green fuel which is produced from different oleaginous biomass. Nevertheless, producing biodiesel from edible feedstock is strongly criticized by Food and Agriculture Organization. Recently, microalgae have been identified as a source that can be the purification factor of wastewater and appropriate feedstock for biodiesel production. The high potential of microalgae to produce biodiesel and low-cost recovery in large-scale production encourage investors to utilize microalgae for biodiesel production. Accordingly, selecting the best locations for microalgae cultivation has a great impact on the economic viability of biodiesel production from microalgae. This paper studies application of a data envelopment analysis (DEA) approach in selecting the best locations for microalgae cultivation through ecological and economic factors. The DEA method is applied to a real case in Iran. Moreover, the well-known principal component analysis and numerical taxonomy methods are used for verification and validation of the applied DEA approach. The results confirm the applicability of the DEA approach in selecting suitable locations for microalgae cultivation areas.

Poly(glycerol-co-diacids) Polyesters: From Glycerol Biorefinery to Sustainable Engineering Applications, A Review

Upgrading of biobased glycerol to commercial products is a necessary step on sustainable development of oleaginous biomass biorefining. The synthesis of poly(glycerol-co-diacid) polyester materials is an attractive option for glycerol usage that can produce a wide range of products of commercial interest. These polymeric materials could be used on industrial applications as biomedical devices, surfactants and in thermoplastic material development. In this review, the process engineering aspects leading to tailorable polymeric products are comprehensively analyzed with emphasis on control of molecular architecture and functionality. Molecular weight, degree of branching, mechanical properties and surface chemistry of the materials can be controlled by fine-tuning synthesis procedures to match custom specifications in end products. Potential usage of poly(glycerol-co-diacid) materials with tailored physicochemical properties on industrially relevant applications is presented. Advantages and challenges in th...

Pyrolytic Fractionation: A Promising Thermochemical Technique for Processing Oleaginous (Algal) Biomass

We report the development of a two-step pyrolytic fractionation approach that is especially applicable to processing oleaginous algae feed stocks. The first step is a low-temperature pyrolysis (T ∼ 300–320 °C) to produce bio-oils from degradation of protein and carbohydrate fractions. Solid residues left behind can subsequently be subjected to a second higher temperature pyrolysis (T ∼ 420–430 °C) to volatilize and/or degrade triglycerides to produce fatty acids, their derivatives, and long chain hydrocarbons. Thus, pyrolytic fractionation can be used to “fractionate” oleaginous biomass and separately recover triglyceride degradation products. Proof-of-concept micropyrolyzer and subsequent lab-scale fixed-bed experiments were performed using oleaginous Chlorella sp. and Scenedesmus sp. to demonstrate the pyrolytic fractionation technique and determine bio-oil yields. As expected, triglyceride-specific bio-oils were rich in hydrocarbons and free fatty acids, were nearly free of water, short-chain organic a...

Quantification of triglyceride content in oleaginous materials using thermo-gravimetry

Laboratory analytical methods for quantification of triglyceride content in oleaginous biomass samples, especially microalgae, require toxic chemicals and/or organic solvents and involve multiple steps. In this paper, a simple triglyceride quantification method that uses thermo-gravimetry is described. This method is based on the observation that triglycerides undergo near-complete volatilization/degradation over a narrow temperature interval with a derivative weight loss peak at 420°C when heated in an inert atmosphere. Degradation of the other constituents of oleaginous biomass (protein and carbohydrates) is largely complete after prolonged exposure of samples at 320°C. Based on these observations, the triglyceride content of oleaginous biomass was estimated by using the following two-step process. In Step 1, samples were heated to 320°C and kept isothermal at this temperature for 15min. In Step 2, samples were heated from 320°C to 420°C and then kept isothermal at 420°C for 15min. Our results show that mass loss in step 2 correlated well with triglyceride content estimates obtained from conventional techniques for diverse microalgae and oilseed samples.

Use of Dual Detection in the Gas Chromatographic Analysis of Oleaginous Biomass Feeds and Biofuel Products To Enable Accurate Simulated Distillation and Lipid Profiling

This contribution describes the development of a chromatographic method capable of simultaneously identifying and quantifying the constituents found in oleaginous biomass—including algae oil—and in biofuel samples through a single cost-effective analysis. Major constituents of the aforementioned analytes include oxygen- and/or nitrogen-containing compounds along with fuel-like hydrocarbons. A novel simulated distillation gas chromatographic (SimDist) technique including dual detection capabilities—specifically flame ionization (FID) and mass spectrometry (MS)—produced identical chromatograms with perfectly aligned signals. FID chromatograms afforded excellent quantitative data while the corresponding MS spectra enabled accurate and thorough compound identification. Simulated distillation data displayed a remarkably linear relationship between retention time and the boiling point of heteroatom-containing compounds in addition to n-alkanes. Indeed, although standard SimDist data were calibrated using the bo...

Direct Methanolysis of Oleaginous Yeast Biomass (<i>Pseudozyma parantarctica</i>) to Microbial Biodiesel

In this study, intracellular lipids of a novel oleaginous biomass of P. parantarctica were converted to biodiesel directly using simple acid catalyst methanolysis. The optimum condition of this method was investigated. Under optimum conditions (0.1 M H2SO4, 10 h reaction time, 65°C reaction temperature, and 1:20 (w/v) biomass-to-methanol ratio), the yield of crude biodiesel was 93.18 ± 2.09% based on total cellular lipids. The composition of crude biodiesel was C16:C18 fatty acid methyl esters (FAMEs) for 91.91%. Especially, the C18:1 methyl ester was the main FAME (47.10%). In addition, the result showed that this technique could produce the microbial biodiesel from biomass containing high free fatty acids (FFAs) without soap formation. The predicted cetane number and kinematic viscosity of biodiesel were characterized according to ASTM D6751 and EN 14214 standards. Our results indicated that this process produces a good quality biodiesel. Moreover, it can decrease the manufacturing costs of microbial biodiesel production from oleaginous yeast biomass without cell disruption and lipid extraction.

Flash Pyrolysis of Oleaginous Biomass in a Fluidized-Bed Reactor

In this study, flash pyrolysis was performed using milled soybean as a model substrate to assess the production of liquid fuels from oleaginous biomass feedstocks. A laboratory-scale fluidized-bed flash pyrolysis reactor that allowed rapid heat transfer to the biomass along with short vapor residence time was designed and constructed. Pyrolysis was performed between 250 and 610 °C with a vapor residence time between 0.2 and 0.3 s. At 550 °C or higher, nearly 70% of the initial feed mass as well as feed carbon was recovered in bio-oil. In addition, 90% of the feedstock lipids were recovered in the bio-oil at these pyrolysis conditions. The high liquid products yields were attributed to (1) the low secondary degradation of bio-oils due to the short vapor residence time and (2) the high recovery of liquids in a novel dry ice packed-bed condenser that provided a high surface area for condensation/aggregation of dilute bio-oil vapors/aerosols that were entrained in the carrier gas. The bio-oil from this study had higher C and H content, higher calorific value, and lower oxygen and water content than bio-oil from wood. These results show that high-quality bio-oil at high yield can be obtained from flash pyrolysis of oleaginous feedstock.

An oleaginous filamentous microalgae Tribonema minus exhibits high removing potential of industrial phenol contaminants

Discharge of industrial phenol contaminants could cause great harm on natural environment. Through oleaginous microalgae cultivation in phenolic wastewater, pollutants can be phototrophically biofixed into biomass as feedstock for bioenergy production. It was firstly reported in this study that, an oleaginous filamentous microalgae Tribonema minus exhibited strong environmental phenol removal ability. T. minus filaments showed 449.46mgg−1 of phenol-uptake capacity, obviously higher than those strains with low phenol absorption such as Scenedesmus dimorphus. And phenols could be removed efficiently at the initial phenol concentration up to 700mgL−1. Simultaneously, through T. minus growth, phenol concentration could be decreased from 100mgL−1 to the range of 0.1–0.5mgL−1, which meet industrial discharge need of phenol contaminants in most countries. So Tribonema minus is a potential algal specie to help the construction of integrated process for both oleaginous biomass production and bioremediation of phenol contaminants.

Kinetic flux profiling dissects nitrogen utilization pathways in the oleaginous green alga Chlorella protothecoides.

As a promising candidate for biodiesel production, the green alga Chlorella protothecoides can efficiently produce oleaginous biomass and the lipid biosynthesis is greatly influenced by the availability of nitrogen source and corresponding nitrogen assimilation pathways. Based on isotope-assisted kinetic flux profiling (KFP), the fluxes through the nitrogen utilization pathway were quantitatively analyzed. We found that autotrophic C. protothecoides cells absorbed ammonium mainly through glutamate dehydrogenase (GDH), and partially through glutamine synthetase (GS), which was the rate-limiting enzyme of nitrogen assimilation process with rare metabolic activity of glutamine oxoglutarate aminotransferase (GOGAT, also known as glutamate synthase); whereas under heterotrophic conditions, the cells adapted to GS-GOGAT cycle for nitrogen assimilation in which GS reaction rate was associated with GOGAT activity. The fact that C. protothecoides chooses the adenosine triphosphate-free and less ammonium-affinity GDH pathway, or alternatively the energy-consuming GS-GOGAT cycle with high ammonium affinity for nitrogen assimilation, highlights the metabolic adaptability of C. protothecoides exposed to altered nitrogen conditions.