Abstract:BackgroundOuter membrane vesicles (OMVs) are nanoparticles released by Gram-negative bacteria and can be used as vaccines. Often, detergents are used to promote release of OMVs and to remove the toxic lipopolysaccharides. Lipopolysaccharides can be detoxified by genetic modification such that vesicles spontaneously produced by bacteria can be directly used as vaccines. The use of spontaneous OMVs has the advantage that no separate extraction step is required in the purification process. However, the productivi… Show more
“…This steady state could be maintained for at least 600 h. The steady-state biomass concentration was OD 590nm = 14 ± 2. Interestingly, steady-state OMV concentrations reached 4 × 10 11 /mL, which is similar to the maximum sOMV concentration reached in batch cultures in which OMV release was triggered by cysteine depletion (Gerritzen et al 2018; Gerritzen et al 2019a). Fig.…”
Section: Resultssupporting
confidence: 69%
“…Recently, we showed high yields of sOMV from a batch cultivation (Gerritzen et al 2019b). This was reached by using a production strain with reduced linkage of the outer membrane to the peptidoglycan in combination with sulfur source depletion (Gerritzen et al 2019a), and high dissolved oxygen levels (Gerritzen et al 2018). Cysteine depletion triggers OMV release (Gerritzen et al 2019a; van de Waterbeemd et al 2013b).…”
Outer membrane vesicles (OMVs) are nanoparticles secreted by Gram-negative bacteria that can be used for diverse biotechnological applications. Interesting applications have been developed, where OMVs are the basis of drug delivery, enzyme carriers, adjuvants, and vaccines. Historically, OMV research has mainly focused on vaccines. Therefore, current OMV production processes have been based on batch processes. The production of OMVs in batch mode is characterized by relatively low yields and high costs. Transition of OMV production processes from batch to continuous processes could increase the volumetric productivity, reduce the production and capital costs, and result in a higher quality product. Here, we study the continuous production of Neisseria meningitidis OMVs to improve volumetric productivity. Continuous cultivation of N. meningitidis resulted in a steady state with similar high OMV concentrations as are reached in current batch processes. The steady state was reproducible and could be maintained for at least 600 h. The volumetric productivity of a continuous culture reached 4.0 × 1014 OMVs per liter culture per day, based on a dilution rate of 1/day. The tested characteristics of the OMVs did not change during the experiments showing feasibility of a continuous production process for the production of OMVs for any application.Electronic supplementary materialThe online version of this article (10.1007/s00253-019-10163-z) contains supplementary material, which is available to authorized users.
“…This steady state could be maintained for at least 600 h. The steady-state biomass concentration was OD 590nm = 14 ± 2. Interestingly, steady-state OMV concentrations reached 4 × 10 11 /mL, which is similar to the maximum sOMV concentration reached in batch cultures in which OMV release was triggered by cysteine depletion (Gerritzen et al 2018; Gerritzen et al 2019a). Fig.…”
Section: Resultssupporting
confidence: 69%
“…Recently, we showed high yields of sOMV from a batch cultivation (Gerritzen et al 2019b). This was reached by using a production strain with reduced linkage of the outer membrane to the peptidoglycan in combination with sulfur source depletion (Gerritzen et al 2019a), and high dissolved oxygen levels (Gerritzen et al 2018). Cysteine depletion triggers OMV release (Gerritzen et al 2019a; van de Waterbeemd et al 2013b).…”
Outer membrane vesicles (OMVs) are nanoparticles secreted by Gram-negative bacteria that can be used for diverse biotechnological applications. Interesting applications have been developed, where OMVs are the basis of drug delivery, enzyme carriers, adjuvants, and vaccines. Historically, OMV research has mainly focused on vaccines. Therefore, current OMV production processes have been based on batch processes. The production of OMVs in batch mode is characterized by relatively low yields and high costs. Transition of OMV production processes from batch to continuous processes could increase the volumetric productivity, reduce the production and capital costs, and result in a higher quality product. Here, we study the continuous production of Neisseria meningitidis OMVs to improve volumetric productivity. Continuous cultivation of N. meningitidis resulted in a steady state with similar high OMV concentrations as are reached in current batch processes. The steady state was reproducible and could be maintained for at least 600 h. The volumetric productivity of a continuous culture reached 4.0 × 1014 OMVs per liter culture per day, based on a dilution rate of 1/day. The tested characteristics of the OMVs did not change during the experiments showing feasibility of a continuous production process for the production of OMVs for any application.Electronic supplementary materialThe online version of this article (10.1007/s00253-019-10163-z) contains supplementary material, which is available to authorized users.
“…Gram-negative bacteria secrete OMVs spontaneously to the culture medium in the process of growth, and OMVs could be enriched and isolated from the cell culture supernatant (19). Other methods to obtain OMVs from bacterial cells included using detergents and/or chelating agents to promote the production of the OMVs (20,21), always with a higher yield than isolation from the culture supernatant (22). In addition to yield, it was proven that the MenB OMVs obtained by varied methods exhibited differences in morphology, protein composition, toxicity, immunogenicity, and even in serum bactericidal activity (SBA) (23)(24)(25).…”
Acinetobacter baumannii (A. baumannii) is becoming a common global concern due to the emergence of multi-drug or pan-drug resistant strains. Confronting the issue of antimicrobial resistance by developing vaccines against the resistant pathogen is becoming a common strategy. In this study, different methods for preparing A. baumannii outer membrane vesicles (AbOMVs) vaccines were developed. sOMV (spontaneously released AbOMV) was extracted from the culture supernatant, while SuOMV (sucrose-extracted AbOMV) and nOMV (native AbOMV) were prepared from the bacterial cells. Three AbOMVs exhibited significant differences in yield, particle size, protein composition, and LPS/DNA content. To compare the protective efficacy of the three AbOMVs, groups of mice were immunized either intramuscularly or intranasally with each AbOMV. Vaccination via both routes conferred significant protection against lethal and sub-lethal A. baumannii challenge. Moreover, intranasal vaccination provided more robust protection, which may be attributed to the induction of significant sIgA response in mucosal sites. Among the three AbOMVs, SuOMV elicited the highest level of protective immunity against A. baumannii infection, whether intramuscular or intranasal immunization, which was characterized by the expression of the most profound specific serum IgG or mucosal sIgA. Taken together, the preparation method had a significant effect on the yield, morphology, and composition of AbOMVs, that further influenced the protective effect against A. baumannii infection.
“…-Accelerostats (A-stats) and deceleration-stats (De-stats), which are used to study the increase or decrease the specific growth rate, respectively (Nahku et al, 2010;Hoekema et al, 2014;Wagenen et al, 2015;Gerritzen et al, 2018). -Dilution rate stats (D-stats), where an environmental parameter is continuously changed while the dilution rate is kept constant (Kasemets et al, 2003).…”
Section: Introductionmentioning
confidence: 99%
“…– Accelerostats (A-stats) and deceleration-stats (De-stats), which are used to study the increase or decrease the specific growth rate, respectively (Nahku et al, 2010 ; Hoekema et al, 2014 ; Wagenen et al, 2015 ; Gerritzen et al, 2018 ).…”
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