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The oil scarcity and the rise in earth temperature have elevated the interest in lignocellulosic biorefineries. Lignin has high potential to be used in various applications including the production of biomaterials and transportation fuels. Among the different sources of lignin, organosolv lignin has the advantage of being sulphur-free and of low ash content compared to other types of industrial lignin. The present study focuses on cradle-to-gate life cycle and cost assessment of a novel organosolv lignin production process from spruce bark. The system boundary included production of tannin, lignin from spruce bark and handling of waste including all the inputs (material and energy) and outputs (emissions) in the process. Baseline scenario and scenarios S1 and S2 were compared to identify the most environmentally and economically suitable scenario. The baseline scenario is lignin production with co-production of tannin and tannin free bark (TFB) from spruce bark; scenario S1 is lignin production from TFB; and scenario S2 is lignin production from TFB with mass allocation. The functional unit was 1 kg lignin produced and ReCiPe 2016 Midpoint (H) method was used for the environmental impact assessment. The results showed that the baseline scenario had higher global warming potential (GWP) (2.14 kg CO(2)eq.) and total cost (1.959 (sic)/kg) than S1 (1.39 kg CO2 eq. and 1.377 (sic)/kg respectively) and S2 (0.23 kg CO(2)eq. and 0.998 (sic)/kg respectively) scenarios. The results of sensitivity analysis showed that the use of bioethanol instead of ethanol reduced the burden on GWP but increased the burden on the land use impact category.

Given an increasing focus on environmental sustainability, microbial oils have been suggested as an alternative to petroleum-based products. However, microbial oil production relies on the use of costly sugar-based feedstocks. Substrate limitation, elevated costs, and risk of contamination have sparked the search for alternatives to sugar-based platforms. Volatile fatty acids are generated during anaerobic digestion of organic waste and are considered a promising substrate for microbial oil production. In the present study, two freshwater and one marine microalga along with two thraustochytrids were evaluated for their potential to produce lipids when cultivated on volatile fatty acids generated from food waste via anaerobic digestion using a membrane bioreactor. Freshwater microalgae Auxenochlorella protothecoides and Chlorella sorokiniana synthesized lipids rich in palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), and linoleic acid (C18:2). This composition corresponds to that of soybean and jatropha oils, which are used as biodiesel feedstock. Production of added-value polyunsaturated fatty acids (PUFA) mainly omega-3 fatty acids was examined in three different marine strains: Aurantiochytrium sp. T66, Schizochytrium limacinum SR21, and Crypthecodinium cohnii. Only Aurantiochytrium sp. T66 seemed promising, generating 43.19% docosahexaenoic acid (DHA) and 13.56% docosapentaenoic acid (DPA) in total lipids. In summary, we show that A. protothecoides, C. sorokiniana, and Aurantiochytrium sp. T66 can be used for microbial oil production from food waste material.

Nanocellulose isolation fromlignocellulose is a tedious and expensive processwith high energy and harsh chemical requirements, primarily due to the recalcitrance of the substrate, which otherwise would have been costeffective due to its abundance. Replacing the chemical steps with biocatalytic processes offers opportunities to solve this bottleneck to a certain extent due to the enzymes substrate specificity and mild reaction chemistry. In this work, we demonstrate the isolation of sulphate-free nanocellulose from organosolv pretreated birch biomass using different glycosyl-hydrolases, along with accessory oxidative enzymes including a lytic polysaccharide monooxygenase (LPMO). The suggested process produced colloidal nanocellulose suspensions (zeta-potential-19.4 mV) with particles of 7-20 nm diameter, high carboxylate content and improved thermostability (T-o= 301 degrees C, T-max= 337 degrees C). Nanocelluloseswere subjected to post-modification using LPMOs of different regioselectivity. The sample from chemical route was the least favorable for LPMO to enhance the carboxylate content, while that from the C1-specific LPMO treatment showed the highest increase in carboxylate content.

Microalgal oils are considered an important source of industrially valuable oleochemicals with significant applications ranging from the energy to pharmaceutical sectors. Industrial production of microalgal oil is emerging rapidly; however, the high cost associated with downstream processes may constrain this process. Oils are accumulated intracellularly in oleaginous microalgae in the form of lipid droplets, which in turn require cell wall disruption followed by extraction in order to recover them. Disruption of the microalgal cell is very challenging owing to its distinctive features like high water content, hard cell wall, presence of algaenan, and sporopollenin like biopolymers that in turn create hurdles in efficient extraction of lipids. Various conventional pretreatment methods have been explored to rupture the cellular integrity of microalgal cells to enhance lipid extraction, and each method has certain advantages and disadvantages. Supercritical fluid extraction is the oldest technique for the extraction of valuable compounds from microalgae and is considered an alternative to conventional solvent extraction methods. It has several advantageous features such as being free from organic solvents (and their disposal), environment-friendly, and operating at a mild range of temperature (40–80°C). CO2 is considered to be an ideal supercritical fluid due to its non-toxic, non-flammable, and lipophilic nature. In this chapter, use of supercritical carbon dioxide extraction of lipids from microalgae is discussed and compared with other available lipid extraction methods., ISBN för värdpublikation: 978-0-12-817388-6

Thraustochytrids are considered natural producers of omega-3 fatty acids as they can synthesize up to 70% docosahexaenoic acids (DHA) of total lipids. However, commercial and sustainable production of microbial DHA is limited by elevated cost of carbon substrates for thraustochytrids cultivation. This problem can be addressed by utilizing low-cost renewable substrates. In the present study, growth, lipid accumulation and fatty acid profiles of the marine thraustochytrid Aurantiochytrium sp. T66 (ATCC-PRA-276) cultivated on volatile fatty acids (C1, formic acid; C2, acetic acid; C3, propionic acid; C4, butyric acid; C5, valeric acid and C6, caproic acid) and glucose as control were evaluated for the first time. This strain showed an inability to utilize C3, C5 and C6 as a substrate when provided at >2 g/L, while efficiently utilizing C2 and C4 up to 40 g/L. The highest cell dry weight (12.35 g/L) and total lipid concentration (6.59 g/L) were attained when this strain was cultivated on 40 g/L of butyric acid, followed by cultivation on glucose (11.87 g/L and 5.34 g/L, respectively) and acetic acid (8.70 g/L and 3.43 g/L, respectively). With 40 g/L butyric acid, the maximum docosahexaenoic acid content was 2.81 g/L, corresponding to 42.63% w/w of total lipids and a yield of 0.23 g/gcell dry weight (CDW). This marine oleaginous microorganism showed an elevated potential for polyunsaturated fatty acids production at higher acetic and butyric acid concentrations than previously reported. Moreover, fluorescence microscopy revealed that growth on butyric acid caused cell size to increase to 45 µm, one of the largest values reported for oleaginous microorganisms, as well as the presence of numerous tiny lipid droplets., Validerad;2020;Nivå 2;2020-05-12 (alebob)

Microalgal oils are considered an important source of industrially valuable oleochemicals with significant applications ranging from the energy to pharmaceutical sectors. Industrial production of microalgal oil is emerging rapidly; however, the high cost associated with downstream processes may constrain this process. Oils are accumulated intracellularly in oleaginous microalgae in the form of lipid droplets, which in turn require cell wall disruption followed by extraction in order to recover them. Disruption of the microalgal cell is very challenging owing to its distinctive features like high water content, hard cell wall, presence of algaenan, and sporopollenin like biopolymers that in turn create hurdles in efficient extraction of lipids. Various conventional pretreatment methods have been explored to rupture the cellular integrity of microalgal cells to enhance lipid extraction, and each method has certain advantages and disadvantages. Supercritical fluid extraction is the oldest technique for the extraction of valuable compounds from microalgae and is considered an alternative to conventional solvent extraction methods. It has several advantageous features such as being free from organic solvents (and their disposal), environment-friendly, and operating at a mild range of temperature (40–80°C). CO2 is considered to be an ideal supercritical fluid due to its non-toxic, non-flammable, and lipophilic nature. In this chapter, use of supercritical carbon dioxide extraction of lipids from microalgae is discussed and compared with other available lipid extraction methods.

The tunicate species Ciona intestinalis is a fast-growing marine invertebrate animal that contains cellulose in its outer part-the tunic. The high crystallinity and microfibril aspect ratio of tunicate cellulose make it an excellent starting material for the isolation of nanocellulose. In the present work, tunic from C. intestinalis was subjected to organosolv pretreatment followed by bleaching and acid-hydrolysis steps for the isolation of nanocrystals. Applying an intermediate enzymatic treatment step with a lytic polysaccharide monooxygenase (LPMO) from the thermophilic fungus Thermothelomyces thermophila was proved to facilitate the isolation of nanocellulose and to improve the overall process yield, even when the bleaching step was omitted. LPMOs are able to oxidatively cleave the glycosidic bonds of a polysaccharide substrate, either at the C1 and/or C4 position, with the former leading to introduction of carboxylate moieties. X-ray photoelectron spectroscopy analysis showed a significant increase in the atomic percentage of the C=O/O-C-O and O-C=O bonds upon the addition of LPMO, while the obtained nanocrystals exhibited higher thermal stability compared to the untreated ones. Moreover, an enzymatic post-treatment with LPMOs was performed to additionally functionalize the cellulose nanocrystals. Our results demonstrate that LPMOs are promising candidates for the enzymatic modification of cellulose fibers, including the preparation of oxidized-nanocellulose, and offer great perspectives for the production of novel biobased nanomaterials.