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Summary This study explores enhancing lipid recovery from the lipid‐rich marine microalgae Aurantiochytrium sp. SW1, known for its robust cell wall posing challenges, which necessitates energy‐intensive cell‐disruption for efficient intracellular lipid extraction. Despite advancements in other microalgae, there is lack of reports on efficient cell disruption for Aurantiochytrium sp. SW1 which is vital to reduce the energy costs and minimising the downstream process while maximising lipid yields. Three process intensification technologies (PIT) – microwave treatment, autoclave treatment and ultrasonication were employed on wet Aurantiochytrium sp. SW1 cells to improve the lipid extraction efficiency. Assessing the disruption effectiveness via lipid content, suspension turbidity and particle size distribution, alongside scanning electron microscopy (SEM) for cellular morphology changes post‐PIT treatments, this study indicates all three methods reduced particle size with prolonged treatment time, implying successful cell wall disruption and intracellular component release. Ultrasonication, especially at 50 W power for 10 min, exhibited the highest efficacy, yielding lipid content of 67.76 ± 0.03%. Microscopic analysis unveiled ultrasonication‐induced cell shrinkage and increased membrane permeability, supporting its effectiveness in enhancing solvent penetration for improved lipid recovery. This research underscores PIT techniques' potential as sustainable, energy‐efficient strategies for lipid extraction from Aurantiochytrium sp. SW1 microalgae. [ABSTRACT FROM AUTHOR]

This paper aims to develop a numerical methodology to investigate the penetration process of nanoneedles into cells and the corresponding force and indentation length. The finite element approach via the explicit dynamic method handles convergence difficulties in the nonlinear phenomenon. The cell is modeled as an isotropic elastic hemiellipsoidal shell with a thickness of 200 nm, which represents the lipid membrane and actin cortex, encapsulating cytoplasm that is regarded as an Eulerian body because of its fluid‐type behavior. Nanoneedles with diameters 400, 200, and 50 nm are considered for model development based on available experimental data. The Von Mises strain failure criterion is used for rupture detection. A parameter study using 1, 2.5, 5, 7.5, and 10 kPa shows that Young's modulus of the HeLa cell membrane is about 5 kPa. Moreover, a failure strain of 1.2 chosen among 0.2, 0.4, 0.6, 0.8, 1, and 1.2 matches best the experimental data. In addition, a diameter study shows that the relations between force‐diameter and indentation length‐diameter are linear and polynomial, respectively. Furthermore, regarding the experimental data and by using contour of minimum principal stress around needle and an analytical equation for calculation of buckling force of a woven fabric, we proposed that for a given cell, membrane structural stability—a function of the coupled effect of Young's modulus and actin meshwork size—contributes directly to needle insertion success rate for that type of cell. [ABSTRACT FROM AUTHOR]

Traditional technology of cell disruption has become one of the bottlenecks restricting the industrialization of genetic engineering products due to its high cost and low efficiency. In this study, a novel bioprocess of phage lysis coupled with salting‐out extraction (SOE) was evaluated. The lysis effect of T7 phage on genetically engineered Escherichia coli expressing κ‐carrageenase was investigated at different multiplicity of infection (MOI), meanwhile the phage and enzyme released into the lysate were separated by SOE. It was found that T7 phage could lyse 99.9% of host cells at MOI = 1 and release more than 90.0% of enzyme within 90 min. After phage lysis, 87.1% of T7 phage and 71.2% of κ‐carrageenase could be distributed at the middle phase and the bottom phase, respectively, in the SOE system composed of 16% ammonium sulfate and 20% ethyl acetate (w/w). Furthermore, κ‐carrageenase in the bottom phase could be salted out by ammonium sulfate with a yield of 40.1%. Phage lysis exhibits some advantages, such as mild operation conditions and low cost. While SOE can efficiently separate phage and intracellular products. Therefore, phage lysis coupled with SOE is expected to become a viable alternative to the classical cell disruption and intracellular product recovery. [ABSTRACT FROM AUTHOR]

The environmental concerns about fossil energy and rising oil prices are regular global phenomena. In such an exigency where fossil fuel sources are dwindling, carbon‐neutral biodiesel derived from microalgae lipid seems to be an important renewable energy resource. In recent years, microalgae have become a lucrative feedstock for economically viability of commercial‐scale biofuel production owing to its high biomass growth and high oil yield compared with other crops. The screening and selection of promising microalgae strain should be based on their fatty acid profile and culture conditions. The laboratory to pilot scale culture of microalgae species requires systematic experimental designs to maximize microalgal growth using open or raceway ponds, closed photo bioreactors and hybrid systems. The pros and cons of each harvesting technique, including filtration, centrifugation, sedimentation and flocculation as well cell disruption by thermal, mechanical, chemical and biological techniques, are deliberated in details. Furthermore, the application of homogeneous, heterogeneous and enzyme catalysts in transesterification processes as well as purification technologies are emphasized to ensure high‐quality biodiesel production as per ASTM norms. Microalgae comprise a potential feedstock and biodiesel synthesis from them requires a series of complex up‐streaming and down‐stream processes which are inherently disadvantageous in technology transfer from laboratory to industrial scale. This review paper is mainly focused on microalgal cultivation, harvesting, oil extraction, biodiesel production and purification technologies, and each vital process is critically reviewed in each step. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This research aimed to develop blends of corn starch and poly(butylene adipate‐co‐terephthalate) (PBAT) films by blown film extrusion with the addition of biomass of Chlorella pyrenoidosa (CP). Two ultrasound tracts disrupted CP biomass: ultrasound bath and ultrasonic probe. The influence of CP biomass and disrupted CP biomass on the physical, mechanical, barrier, structural, and thermal properties of starch/PBAT films was evaluated. The film with higher content (5.0%) of CP biomass showed better values in tensile strength (TS) (4.37 MPa) and elongation (88.43%), and lower water vapor permeability (WVP) (5.19 × 10−11 g m−1 s−1 Pa−1) than the film incorporated with disrupted CP biomass. The ultrasound treatment applied to the cell disruption of the microalgae did not present improvements in the properties of the films. In this context, the cell disruption of CP biomass by ultrasound for incorporation into biodegradable films was not feasible. However, it was possible to produce starch/PBAT/microalgae films with potential application as food packaging due to natural bio‐pigmentation's protection system against ultraviolet light. Practical Applications: Films produced by blown extrusion from starch, PBAT, and CP microalgae biomass have the technological potential to be used as packaging for food products. Starch and PBAT blends are widely studied. The incorporation of PBAT is necessary to confer adequate mechanical properties to the extruded material. The plastic industries already use the blown extrusion method, allowing biodegradable packaging development on an industrial scale. [ABSTRACT FROM AUTHOR]

Background and Objectives: Assessment of plasma quality often focuses on the common safety tests for minimizing the risk of transmitting blood‐borne pathogens. Little attention is paid to the possible quality attributes that ensure a consistent biochemical composition of plasma for fractionation. We therefore investigated the suitability of selected biochemical and haematological attributes that could be used as markers of plasma quality obtained by different separation and pre‐treatment procedures. Material and Methods: We characterized six plasma types, including source plasma, plasma recovered by classic means and in‐line filtered plasma, by determining the analytical attributes protein content, coagulation factors and markers of coagulation, contact and complement activation. Residual cell content and cell‐specific variables were also measured. Results: We found relevant differences between the plasma types in complement activation, as indicated by C3a measurements, while thrombin antithrombin complex values and, to a minor extent, activated factor XII concentrations indicated only moderate differences in activation levels of coagulation and contact systems. The most striking differences, however, were detected in residual cell content and concentrations of the platelet‐associated proteins, platelet factor 4 and β‐thromboglobulin. We showed that leucocyte reduction filters disrupt cells. This includes platelets, thereby releasing the platelet‐associated proteins platelet factor 4 and β‐thromboglobulin, and leucocytes as demonstrated by the release of elastase from polymorphonuclear leucocytes. Furthermore, the filtration processing of whole blood can lead to activation of the complement system. Conclusion: Our results show that biochemical and cellular surrogate markers are valuable discriminators of plasma types. [ABSTRACT FROM AUTHOR]

The application of integrated microbioreactor systems is rapidly becoming of more interest to accelerate strain characterization and bioprocess development. However, available high‐throughput screening capabilities are often limited to target extracellular compounds only. Consequently, there is a great demand for automated technologies allowing for miniaturized and parallel cell disruption providing access to intracellular measurements. In this study, a fully automated bead mill workflow was developed and validated for four different industrial platform organisms: Escherichia coli, Corynebacterium glutamicum, Saccharomyces cerevisiae, and Aspergillus niger. The workflow enables up to 48 parallel cell disruptions in microtiter plates and is applicable at‐line to running lab‐scale cultivations. The resulting cell extracts form the basis for quantitative omics studies where no rapid metabolic quenching is required (e.g., genomics and proteomics). [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate ruminal fermentation and the nutritional value of different microalgae products (MAP) for ruminants, including inter‐ and intra‐genera variability. Furthermore, the effect of mechanical cell disruption was also evaluated. Cell‐disrupted and nondisrupted MAP of four genera were investigated using the Hohenheim Gas Test. The investigations included characterization of gas production (GP), production of volatile fatty acids (VFA) and methane, organic matter digestibility, and energetic value as well as utilizable crude protein at the duodenum and ruminally undegradable crude protein (RUP). Furthermore, a three‐step enzymatic in vitro system was used to estimate intestinal digestibility of RUP (IDP). Ruminal fermentation was low for all investigated microalgae genera, as indicated by overall low GP, low production of VFA, and low ruminal protein degradation. Nevertheless, all microalgae genera were characterized by high RUP concentrations (236–407 g/kg dry matter; passage rate = 8% hr−1), indicating that microalgae might be a promising protein source for high‐performing ruminants. Low IDP (26%–49% of RUP) considerably contradicted this potential. Mechanical cell disruption in general enhanced the extent of ruminal fermentation of MAP but, as RUP was decreased and IDP was hardly affected, mechanical cell disruption appears not to be necessary when microalgae are intended for application as a protein source for ruminants. Because of the high variability in the characteristics of the nutritional value, general means are inappropriate to characterize the nutritional value of MAP. In conclusion, suitability of microalgae as a protein source for ruminants might be limited because of low IDP, although further studies are necessary to prove these findings in vivo. Ruminal fermentation of cell‐disrupted and nondisrupted microalgae and the consequences for the nutritional value for ruminants were investigated using different in vitro methods. The results showed a high variability between and within microalgae genera in the nutritional characteristics and in the effect of cell disruption. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the feasibility of using irreversible electroporation (EP) as a microbial cell disruption technique to extract intracellular lipid within short time and in an eco‐friendly manner. An EP circuit was designed and fabricated to obtain 4 kV with frequency of 100 Hz of square waves. The yeast cells of Lipomyces starkeyi (L. starkeyi) were treated by EP for 2‐10 min where the distance between electrodes was maintained at 2, 4, and 6 cm. Colony forming units (CFU) were counted to observe the cell viability under the high voltage electric field. The forces of the pulsing electric field caused significant damage to the cell wall of L. starkeyi and the disruption of microbial cells was visualized by field emission scanning electron microscopic (FESEM) image. After breaking the cell wall, lipid was extracted and measured to assess the efficiency of EP over other techniques. The extent of cell inactivation was up to 95% when the electrodes were placed at the distance of 2 cm, which provided high treatment intensity (36.7 kWh m−3). At this condition, maximum lipid (63 mg g−1) was extracted when the biomass was treated for 10 min. During the comparison, EP could extract 31.88% lipid while the amount was 11.89% for ultrasonic and 16.8% for Fenton's reagent. The results recommend that the EP is a promising technique for lowering the time and solvent usage for lipid extraction from microbial biomass. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:838–845, 2018 [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Green fluorescent protein (GFP) is used extensively as a biomarker due to its unique spectral and fluorescence characteristics. GFP is usually obtained from recombinant strains of Escherichia coli (E. coli) producing the protein intracellularly. However, the common methods of extraction are cumbersome leading to an increase in the downstream process costs and complexity, sometimes leading to a higher risk of biomolecule degradation. RESULTS: This work proposes a new method to extract recombinant intracellular GFP from E. coli BL21 by using aqueous solutions of surface‐active compounds. CONCLUSION: By comparing the fluorescence intensity of the extracted GFP, it was concluded that some of these compounds, namely ionic liquids with an alkyl chain of 10 or more carbons (best solvent being tributyl‐1‐tetradecylphosphonium, [P4,4,4,14]Cl) are more effective than an ultrasonic‐assisted extraction, even at low concentrations, being able to extract the whole GFP content from the cells. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Microalgae are considered an interesting candidate for the sustainable production of edible oils. Because microalgae contain abundant polyunsaturated fatty acids (PUFA) and have high photosynthetic rates and high oil productivity, they are superior to terrestrial oleaginous crops for producing edible oils. Microalgae are cultivated in aquatic environments, and thus, oil extraction methods for microalgae must consider the influence of water. This paper provides an overview of the suitability of microalgal lipid compositions and proposes a selection of species for edible oil production. The numerous technologies currently available for pretreatment, wet extraction and the refining of edible oils from microalgae are collated and presented, with a primary focus on the key parameters influencing process performance. Furthermore, the paper presents a proposed solution for a microalgae integrated system for edible oil production, which is a possible future direction to develop an economical and environmentally friendly process for the resource utilization of microalgal biomass. Practical Application: Microalgae might be the most promising source of edible oils, with potential applications in food industrialization, due to its rich oil content and its characteristic fatty acid composition. The review provides a selection criterion of microalgal species to help researchers exploit microalgae to produce superior edible oils for human consumption. Various process parameters and wet extraction methods are discussed that may be conducive to improving process performance and achieving high oil recovery yields. By considering the maximum utilization of microalgal biomass, an integrated system in this review would assist in economical production during further studies. Microalgae are the most promising candidates for edible oil production. Cell disruption, extraction, and refining are important processes for microalgal oils and on this basis, wet extraction and resource utilization can further promote the economic feasibility of microalgal process. [ABSTRACT FROM AUTHOR]

Although Nannochloropsis lipids have many potential applications in biofuels and high value products, their extraction is limited by the tough cell wall of this species. High pressure homogenization (HPH) can be used to improve the extraction efficiency. However, this can possibly induce free fatty acid (FFA) formation, which has a negative impact on oil quality. In this study, the HPH pressure and number of passes are varied in a full factorial design to study the impact of these factors on FFA formation, lipid extraction efficiency, and fatty acid profile. It is found that substantial amounts of FFA are formed during HPH treatments when compared to the non‐disrupted biomass. The FFA formation is mostly influenced by the number of passes applied, which can explained by a combined effect of the longer time residing as a wet paste and the temperature increase during the treatment. The large amount of FFA formed during the least intensive HPH treatment is in contrast with only a slight increase of the lipid extraction efficiency, which indicates that minor damage to the cell is sufficient to induce lipolytic reactions. The relative fatty acid profile after HI extraction is not influenced by the HPH treatment. Practical Applications: These results have important implications for the application of HPH treatments on microalgae with the aim to improve the extraction efficiency. It is demonstrated that more intensive HPH treatments with several passes are necessary to improve the extraction efficiency of Nannochloropsis lipids. However, the least intensive HPH treatments (1 pass at 400 bar) already induced the formation of substantial amounts of FFA. Consequently, to produce a biomass with a low FFA content and a high lipid extraction efficiency, a compromise should thus be made. High pressure homogenization (HPH) can efficiently be used to improve the extraction effiency of interesting compounds from Nannochloropsis cells. However, this treatment also induces the formation of free fatty acids (FFA), which have a negative influence on oil quality. [ABSTRACT FROM AUTHOR]

The time and cost benefits of miniaturized fermentation platforms can only be gained by employing complementary techniques facilitating high‐throughput at small sample volumes. Microbial cell disruption is a major bottleneck in experimental throughput and is often restricted to large processing volumes. Moreover, for rigid yeast species, such as Pichia pastoris, no effective high‐throughput disruption methods exist. The development of an automated, miniaturized, high‐throughput, noncontact, scalable platform based on adaptive focused acoustics (AFA) to disrupt P. pastoris and recover intracellular heterologous protein is described. Augmented modes of AFA were established by investigating vessel designs and a novel enzymatic pretreatment step. Three different modes of AFA were studied and compared to the performance high‐pressure homogenization. For each of these modes of cell disruption, response models were developed to account for five different performance criteria. Using multiple responses not only demonstrated that different operating parameters are required for different response optima, with highest product purity requiring suboptimal values for other criteria, but also allowed for AFA‐based methods to mimic large‐scale homogenization processes. These results demonstrate that AFA‐mediated cell disruption can be used for a wide range of applications including buffer development, strain selection, fermentation process development, and whole bioprocess integration. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:130–140, 2018 [ABSTRACT FROM AUTHOR]

Efficient and reproducible cell lysis is a crucial step during downstream processing of intracellular products. The composition of an optimal lysis buffer should be chosen depending on the organism, its growth status, the applied detection methods, and even the target molecule. Especially for high-throughput applications, where sample volumes are limited, the adaptation of a lysis buffer to the specific campaign is an urgent need. Here, we present a general design of experiments-based strategy suitable for eight constituents and demonstrate the strength of this approach by the development of an efficient lysis buffer for Gram-negative bacteria, which is applicable in a high-throughput format in a short time. The concentrations of four lysis-inducing chemical agents EDTA, lysozyme, Triton X-100, and polymyxin B were optimized for maximal soluble protein concentration and ß-galactosidase activity in a 96-well format on a Microlab Star liquid handling platform under design of experiments methodology. The resulting lysis buffer showed the same performance as a commercially available lysis buffer. The developed protocol resulted in an optimized buffer within only three runs. The established procedure can be easily applied to adapt the lysis buffer to other strains and target molecules. [ABSTRACT FROM AUTHOR]

Microalgal cultures are a clean and sustainable means to use solar energy for CO2 fixation and fuel production. Microalgae grow efficiently and are rich in oil, but recovering that oil is typically expensive and consumes much energy. Therefore, effective and low-cost techniques for microalgal disruption and oil or lipid extraction are required by the algal biofuel industry. This study introduces a novel technique that uses active extracellular substances to induce microalgal cell disruption. A bacterium indigenous to Taiwan, Bacillus thuringiensis, was used to produce the active extracellular substances, which were volatile compounds with high thermal stability. Approximately 74% of fresh microalgal cells were disrupted after a 12-h treatment with the active extracellular substances. Algal lipid extraction efficiency was improved and the oil extraction time was decreased by approximately 37.5% compared with the control treatment. The substances effectively disrupted fresh microalgal cells but not dehydrated microalgal cells. An analysis of microalgal DNA from fresh cells after disruption treatment demonstrated typical DNA laddering, indicating that disruption may have resulted from programmed cell death. This study revealed that biological treatments are environmentally friendly methods for increasing microalgal lipid extraction efficiency, and introduced a microalgal cell self-disruption mechanism. [ABSTRACT FROM AUTHOR]

In this work, Chlorella pyrenoidosa was chosen as model microalgae, and several pretreatments, including hydroxyl-peroxide-aided ultrasonic pretreatments and mono-ultrasonication (US), were used to rupture the microalgal cells for extracting cellular inclusion. The disruption efficiency and the energy consumption of each technique were estimated through measuring the amount of released protein from cells and the microscopic images after pretreatment. Results showed that the combined pretreatments obtained a much higher lysis efficiency than did the US (over twofold). However, the concentration of H2O2 used (ranging from 0.1 to 5 mM) failed to influence the lysis efficiency significantly ( P < 0.05). Additionally, the acoustic energy efficiency was increased with the initial cell concentration treated, but the coefficient of utilization of algal biomass was decreased significantly. Therefore, an ideal initial cell concentration (13.4 × 107 cells/mL) was gained in terms of the higher coefficient of utilization of algal biomass. This research suggested that a synergistic technique could be an effective pretreatment for microalgal cell disruption and downstream comprehensive utilization. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The study of in situ gas explosion to lyse the triglyceride-rich cells involves the solubilization of gas (e.g., carbon dioxide, CO2) in lipid-rich cells under pressure followed by a rapid decompression, which allows the gas inside the cell to rapidly expand and rupture the cell from inside out. The aim of this study was to perform the cell disruption using pressurized CO2 as well as to determine the solubility of CO2 in Rhodotorula glutinis cell suspension, sugar broth media, and spent media. Cell disruption of R. glutinis was performed at two pressures of 2,000 and 3,500 kPa, respectively, at 295.2 K, and it was found from both scanning electron microscopy (SEM) and plate count that a substantial amount of R. glutinis was disrupted due to the pressurized CO2. We also found a considerable portion of lipid present in the aqueous phase after the disruption at P = 3,500 kPa compared to control (no pressure) and P = 2,000 kPa, which implied that more intracellular lipid was released due to the pressurized CO2. Solubility of CO2 in R. glutinis cell suspension was found to be higher than the solubility of CO2 in both sugar broth media and spent media. Experimental solubility was correlated using the extended Henry's law, which showed a good agreement with the experimental data. Enthalpy and entropy of dissolution of CO2 were found to be −14.22 kJ mol−1 and 48.10 kJ mol−1 K−1, 9.64 kJ mol−1 and 32.52 kJ mol−1 K−1, and 7.50 kJ mol−1 and 25.22 kJ mol−1 K−1 in R. glutinis, spent media, and sugar broth media, respectively. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:737-748, 2017 [ABSTRACT FROM AUTHOR]

Microalgae emerge as the most promising protein sources for aquaculture industry. However, the commercial proteins production at low cost remains a challenge. The process of harnessing microalgal proteins involves several steps such as cell disruption, isolation and extraction. The discrete processes are generally complicated, time-consuming and costly. To date, the notion of integrating microalgal cell disruption and proteins recovery process into one step is yet to explore. Hence, this study aimed to investigate the feasibility of applying methanol/potassium ATPS in the integrated process for proteins recovery from Chlorella sorokiniana. Parameters such as salt types, salt concentrations, methanol concentrations, NaCl addition were optimized. The possibility of upscaling and the effectiveness of recycling the phase components were also studied. The results showed that ATPS formed by 30% (w/w) K3PO4 and 20% (w/w) methanol with 3% (w/w) NaCl addition was optimum for proteins recovery. In this system, the partition coefficient and yield were 7.28 and 84.23%, respectively. There were no significant differences in the partition coefficient and yield when the integrated process was upscaled to 100-fold. The recovered phase components can still be recycled effectively at fifth cycle. In conclusions, this method is simple, rapid, environmental friendly and could be implemented at large scale. [ABSTRACT FROM AUTHOR]

Crude proteins and pigments were extracted from different microalgae strains, both marine and freshwater. The effectiveness of enzymatic pre-treatment prior to protein extraction was evaluated and compared to conventional techniques, including ultrasonication and high-pressure water extraction. Enzymatic pre-treatment was chosen as it could be carried out at mild shear conditions and does not subject the proteins to high temperatures, as with the ultrasonication approach. Using enzymatic pre-treatment, the extracted proteins yields of all tested microalgae strains were approximately 0.7 mg per mg of dry cell weight. These values were comparable to those achieved using a commercial lytic kit. Ultrasonication was not very effective for proteins extraction from Chlorella sp., and the extracted proteins yields did not exceed 0.4 mg per mg of dry cell weight. For other strains, similar yields were achieved by both treatment methods. The time-course effect of enzymatic incubation on the proteins extraction efficiency was more evident using laccase compared to lysozyme, which suggested that the former enzyme has a slower rate of cell disruption. The crude extracted proteins were fractionated using an ion exchange resin and were analyzed by the electrophoresis technique. They were further tested for their antioxidant activity, the highest of which was about 60% from Nannochloropsis sp. The total phenolic contents in the selected strains were also determined, with Chlorella sp. showing the highest content reaching 17 mg/g. Lysozyme was also found to enhance the extraction of pigments, with Chlorella sp. showing the highest pigments contents of 16.02, 4.59 and 5.22 mg/g of chlorophyll a, chlorophyll b and total carotenoids, respectively. [ABSTRACT FROM AUTHOR]

Cell disruption is an inevitable step in many processes for the recovery of intracellular products. Currently, those processes are still energy-intensive and cost-ineffective, in particular with regard to low-cost bulk products such as biodiesel from microalgae. Characteristics of cell disruption were studied by compressive testing of single cells of Chlorella vulgaris with a nanoindenter. Results showed that bursting force as well as energy increased and the percentage of burst cells decreased with higher osmolality. The observations on microscopic level could also be transferred on macroscopic level using a stirred-media mill for cell disruption. The results of the cell disruption were compared to the findings of the compression tests and evaluated under energetic aspects. [ABSTRACT FROM AUTHOR]

Nannochloropsis is a genus of unicellular eukaryotes known primarily from the marine environment whose members are potential sources of lipids and long-chain polyunsaturated fatty acids; for the extraction of these and other valuable cell components, cell disruption is needed. High pressure homogenization (HPH) would be particularly suitable for microalgae with a recalcitrant cell wall such as Nannochloropsis. HPH conditions should be determined based on both the target cell component and properties of the cell suspension that in some cases are dependent on the age of the culture. The yields of soluble protein and total sugars from N. oculata ranged from 22.7 to 50.4 mg/g and from 55.0 to 62.5 mg/g, respectively, depending on HPH conditions (loading pressure and number of passes). The yield of the lipids extracted with the method of Bligh and Dyer was not affected by HPH conditions whereas lipids extracted with Soxhlet method ranged between 8.2 and 16.2%. Main fatty acids in the lipids extracted with the method of Bligh and Dyer and total lipids were palmitic acid (17.2 ± 0.1-23.0 ± 0.2%), palmitoleic acid (22.9 ± 0.3-19.1 ± 0.9%), and eicosapentaenoic acid (20.6 ± 0.3-29.2 ± 0.3%). HPH of N. oculata cells promoted a different effect on particle size distribution (PSD) depending on the age of the culture. HPH reduced cell aggregation observed in the 10 day cell suspension, whereas it promoted aggregation of the 30 day cell suspension. Practical applications: The feasibility of producing a wide range of products from microalgae is determined by the culture conditions and the conditions of the stages in the downstream processing. Because main microalgae components are intracellular, a scalable cell disruption operation such as HPH is required. Cell disruption degree is determined not only by the equipment design and its operational conditions but also by the cell suspension properties. The results allowed us to conclude that a different combination loading pressure/number of passes in HPH maximizes the recovery of hydrosoluble compounds (proteins and sugars) and lipids in N. oculata. Besides, since the PSD of the microalgae suspension is a function of culture age, this variable could affect process productivity. The effects of HPH conditions on the subsequent recovery of hydrosoluble intracellular components (protein and sugars) and the extraction of lipids accumulated by N. oculata were determined. The best combination of the operation conditions for HPH was used for the recovery of the studied components from the microalgae harvested at different periods (culture age). Particle size distribution (PSD) of the cell suspension before and after homogenization was determined to test the effect of culture age on cell disruption. Our results suggest that the conditions of HPH of N. oculata should be defined considering the component of interest. [ABSTRACT FROM AUTHOR]

Cell disruption is an important step used to substantially increase lipid recovery prior to extraction. This is the first study exploring the effects of cell disruption methods on lipid recovery from different oleaginous microorganisms. Specifically, we examined the effects of cell disruption methods, including autoclaving, bead-beating, microwaving, sonication, acid digestion, and Soxhlet extraction on the yeast Cryptococcus curvatus, the fungus Mortierella isabellina and the microalga Chlorella sorokiniana. Although lipid recovery by cell disruption methods varied with microbial species, autoclaving and microwaving resulted in the lowest lipid contents for all tested strains. The Soxhlet method achieved the highest lipid content of 63.4% for M. isabellina and 12.8% for C. sorokiniana, followed by acid digestion. The highest lipid content of C. curvatus was achieved at 47.3% through acid digestion, compared to sonication, bead-beating and Soxhlet methods. This study suggests that acid digestion may be the most simple and effective method for lipid recovery from the tested species in terms of time and reaction temperature. Moreover, fatty acid profile analysis revealed that lipids extracted by acid digestion were similar to those from untreated microbial cells, indicating a favorable feedstock for use in biodiesel production. Practical applications: An effective cell disruption method is critical for not only enhancing the lipid recovery in a large scale but also reporting the accurate values of lipid contents of microorganisms in a lab scale. Different cell disruption methods have different effects on lipid extraction from different microorganisms. In this work, for the first time, we performed comparative investigations among yeast, fungus, and microalga to reveal the lipid recovery yields by cell disruption methods for microbial lipid extraction from different oleaginous microorganisms and identified their most effective methods for analytical lipid determination. An effective cell disruption method is critical for enhancing lipid recovery and reporting the accurate lipid contents of microorganisms. In this study, the authors performed comparative investigations among yeast, fungus, and microalga to determine the lipid recovery yields from these oleaginous micro organisms using various cell disruption methods. They identified the most effective cell disruption methods for analytical lipid determination in each microorganism. [ABSTRACT FROM AUTHOR]

Identification of cost-effective cell disruption methods to facilitate lipid extraction from microalgae represents a crucial step in identifying promising biofuel-producing species. Various cell disruption methods including autoclaving, microwave, osmotic shock, and pasteurization were tested in the microalgae Chlorococcum sp. MCC30, Botryococcus sp. MCC31, Botryococcus sp. MCC32, and Chlorella sorokiniana MIC-G5. Lipid content (on dry weight basis) from the four cultures on day 7 ranged from 11.15 to 48.33%, and on day 14 from 11.42 to 44.26%. Among the methods tested, enhanced lipid extraction was achieved through osmotic shock (15% NaCl) for Botryococcus sp. MCC32, microwave (6 min) for Botryococcus sp. MCC31, osmotic shock (5% NaCl) for Chlorella sorokiniana MIC-G5 and microwave (2 min) for Chlorococcum sp. MCC30. The highest palmitate (16:0) contents (25.64% and 34.20%) were recorded with osmotic shock (15% NaCl) treatment for Botryococcus sp. MCC32 and microwave (6 min) for Botryococcus sp. MCC31, respectively. Two strains, along with their respective cell disruption methods, were identified as promising oil blends or nutraceuticals due to their high unsaturated fatty acid (UFA) content: Botryococcus sp. MCC31 (37.6% oleic acid content; 39.37% UFA) after autoclaving and Botryococcus sp. MCC32 after osmotic shock of 15% NaCl treatment (19.95% oleic acid content; 38.17% UFA). [ABSTRACT FROM AUTHOR]

An efficient isolation of mitochondria from cells under physiological conditions is crucial for many studies in life sciences but still challenging in many cases such as in metabolic characterization of mitochondria. In this work, four methods for the disruption of Chinese hamster ovary cells were evaluated regarding their influence on mitochondrial integrity and yield. After cell disruption, mitochondria released from cells were separated from the remaining cell homogenate by differential centrifugation. Sonication was shown to be a rapid and sensitive isolation method. Yields of 14.0 ± 0.3 mg raw mitochondrial protein per 108 cells were obtained. The mitochondria were morphologically intact, with membrane integrities of 67% (outer membrane) to 94% (inner membrane). Compared with the methods using Dounce homogenization, digitonin permeabilization, or electroporation for cell disruption the ultrasound method provided the highest yield of isolated mitochondria. Furthermore, this method is rapid (≈ 45 s for disruption), more robust than Dounce homogenization regarding their influence on mitochondrial integrity and especially suitable for preparing a relatively large amount of mitochondria. The results of this work can be helpful for quantitative and dynamic studies of molecular processes related to mitochondria under physiological conditions for many questions in both biomedicine and biotechnology. [ABSTRACT FROM AUTHOR]

The time and cost benefits of miniaturized fermentation platforms can only be gained by employing complementary techniques facilitating high-throughput at small sample volumes. Microbial cell disruption is a major bottleneck in experimental throughput and is often restricted to large processing volumes. Moreover, for rigid yeast species, such as Pichia pastoris, no effective high-throughput disruption methods exist. The development of an automated, miniaturized, high-throughput, noncontact, scalable platform based on adaptive focused acoustics (AFA) to disrupt P. pastoris and recover intracellular heterologous protein is described. Augmented modes of AFA were established by investigating vessel designs and a novel enzymatic pretreatment step. Three different modes of AFA were studied and compared to the performance high-pressure homogenization. For each of these modes of cell disruption, response models were developed to account for five different performance criteria. Using multiple responses not only demonstrated that different operating parameters are required for different response optima, with highest product purity requiring suboptimal values for other criteria, but also allowed for AFA-based methods to mimic large-scale homogenization processes. These results demonstrate that AFA-mediated cell disruption can be used for a wide range of applications including buffer development, strain selection, fermentation process development, and whole bioprocess integration. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:130-140, 2018., (© 2017 American Institute of Chemical Engineers.)

The study of in situ gas explosion to lyse the triglyceride-rich cells involves the solubilization of gas (e.g., carbon dioxide, CO 2 ) in lipid-rich cells under pressure followed by a rapid decompression, which allows the gas inside the cell to rapidly expand and rupture the cell from inside out. The aim of this study was to perform the cell disruption using pressurized CO 2 as well as to determine the solubility of CO 2 in Rhodotorula glutinis cell suspension, sugar broth media, and spent media. Cell disruption of R. glutinis was performed at two pressures of 2,000 and 3,500 kPa, respectively, at 295.2 K, and it was found from both scanning electron microscopy (SEM) and plate count that a substantial amount of R. glutinis was disrupted due to the pressurized CO 2 . We also found a considerable portion of lipid present in the aqueous phase after the disruption at P = 3,500 kPa compared to control (no pressure) and P = 2,000 kPa, which implied that more intracellular lipid was released due to the pressurized CO 2 . Solubility of CO 2 in R. glutinis cell suspension was found to be higher than the solubility of CO 2 in both sugar broth media and spent media. Experimental solubility was correlated using the extended Henry's law, which showed a good agreement with the experimental data. Enthalpy and entropy of dissolution of CO 2 were found to be -14.22 kJ mol -1 and 48.10 kJ mol -1  K -1 , 9.64 kJ mol -1 and 32.52 kJ mol -1  K -1 , and 7.50 kJ mol -1 and 25.22 kJ mol -1  K -1 in R. glutinis, spent media, and sugar broth media, respectively. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:737-748, 2017., (© 2017 American Institute of Chemical Engineers.)

A motor-driven Pyrex tissue grinder (PTG) and the B. Braun cell homogenizer (BH) were used to disrupt cells of Selenastrum capricornutum Printz for chlorophyll extraction. Cell disruption efficiency depended upon the number of cells filtered. Within the range of 2 × 10[SUP6] To 8-9 × 10[SUP6] Algal cells per 2.4 cm filter, the PTG allowed more complete extractions. Beyond that number of cells, the BH was more efficient. The algal mass corresponding to 8-9 × 10[SUP6] Cells was 0.14-0.17 mg dry weight. [ABSTRACT FROM AUTHOR]