Search Results (29)

Background: The callus cultures from the fronds of the lycophyte Phlegmariurus taxifolius produce the huperzine A (HupA) alkaloid, which is used in Alzheimer’s disease treatment. This study aimed to establish the growth kinetics and HupA production by the newly HupS21 cell line grown in 250 mL flasks and in a 2 L airlift bioreactor. Methods: Batch-type kinetics were carried out for 60 days in 250 mL flasks and for 20 days in a 2 L airlift bioreactor. Measurements of dry weight (DW), specific growth rate (μ), doubling time (dt), pH, carbohydrate consumption, and HupA quantification were performed. The acetylcholinesterase (AChE) inhibitory assay of the HupS21 alkaloidal extract was determined. Results: The 250 mL flasks kinetic reached a maximum cell growth of 8.17 g/L DW, with a μ of 0.045 day⁻¹ and a dt of 15.40 days. The maximum HupA production was of 2.03 μg/g DW at day 45. In the 2 L airlift reactor, a maximum growth of 16.70 g/L DW, a μ of 0.062 day⁻¹, a dt of 11.20 days, and HupA production of 2.48 μg/g DW at day 15 were obtained. The alkaloidal extract from the HupS21 cell line at 100 μg/mL showed an AChE inhibitory activity of 85.6 ± 1.27%. Conclusions: The airlift reactor outperformed the flask cultures in maximum cell growth, specific growth rate, doubling time, and HupA production. To our knowledge, this research is the first report on the establishment of suspension cell cultures of P. taxifolius in shaken flasks and in an airlift bioreactor, providing a foundation for scaling up HupA production for pharmaceutical use. Full article

The primary aim of this work was to share the results from a Research Project supported by the Italian National Research Council, which led to the development of a versatile jacketed tower bioreactor. Designed to optimize oxygen transfer efficiency and process control, the reactor incorporated a reciprocating air compressor, centrifugal pumps, a draft tube with or without perforated plates, and a series of gas–liquid ejectors. Its flexible design enabled operation in both airlift and ejector-loop modes, making it suitable for a wide range of aerobic fermentation processes. By sharing the detailed engineering design, operational procedures of this pilot-scale bioreactor, as well as its performance data when cultivating yeasts on whey and potato wastewater, a detailed blueprint was given to researchers seeking to advance bioreactor technology, particularly in the context of emerging fields like cultured meat production, pharmaceutical manufacturing, and environmental bioremediation. Full article

Nitrogen-rich wastewater is a major environmental issue that requires proper treatment before disposal. This comprehensive overview covers biological, physical, and chemical nitrogen removal methods. Simultaneous nitrification–denitrification (SND) is most effective in saline water when utilizing both aerobic and anoxic conditions with diverse microbial populations for nitrogen removal. Coupling anammox with denitrification could increase removal rates and reduce energy demand. Suspended growth bioreactors effectively treated diverse COD/N ratios and demonstrated resilience to low C/N ratios. Moving biofilm bioreactors exhibit reduced mortality rates, enhanced sludge–liquid separation, increased treatment efficiency, and stronger biological structures. SND studies show ≥90% total nitrogen removal efficiency (%RE_TN) in diverse setups, with Defluviicoccus, Nitrosomonas, and Nitrospira as the main microbial communities, while anammox–denitrification achieved a %RE_TN of 77%. Systems using polyvinyl alcohol/sodium alginate as a growth medium showed a %RE_TN ≥ 75%. Air-lift reflux configurations exhibited high %RE_TN and %RE_NH4, reducing costs and minimizing sludge formation. Microwave pretreatment and high-frequency electric fields could be used to improve the %RE_NH4. Adsorption/ion exchange, membrane distillation, ultrafiltration, and nanofiltration exhibit promise in industrial wastewater treatment. AOPs and sulfate-based oxidants effectively eliminate nitrogen compounds from industrial wastewater. Tailoring proposed treatments for cost-effective nitrogen removal, optimizing microbial interactions, and analyzing the techno-economics of emerging technologies are crucial. Full article

Microalgae offer a promising solution for efficiently treating high-nitrogen wastewater and recovering valuable nutrients. To optimize microalgae growth and nutrient assimilation, case-dependent studies are essential to demonstrate the process’s potential. This study aimed to evaluate the treatment capacity of high-nitrogen anaerobic digestion effluent as a nutrient source for a C. sorokiniana microalgal culture in a tubular photobioreactor. The study had two primary objectives: to assess how the concentration and composition of the digestate influence microalgae growth, and to identify the preferred nitrogen forms assimilated by the microalgae during long-term, continuous operation. A 20 L tubular airlift bioreactor was constructed and used in batch mode; various digestate concentrations were examined with ammonia nitrogen levels reaching to 160 mg/L. These experiments revealed a biomass growth rate of up to 130 mg/L/d and an ammonia nitrogen assimilation rate ranging from 8.3 to 12.5 mg/L/d. The presence of phosphorous proved essential for microalgae growth, and the growth entered a stationary phase when the initial phosphorous was fully assimilated. A nitrogen-to-phosphorous (N/P) ratio of 10 supported efficient species growth. While ammonia was the preferred nitrogen form for microalgae, they could also utilize alternative forms such as organic and nitrate nitrogen, depending on the specific digestate properties. The results from the continuous photobioreactor operation confirmed the findings from the batch mode, especially regarding the initial nitrogen and phosphorous content. An important condition for nearly complete ammonia removal was the influent dilution rate, to balance the nitrogen assimilation rate. Moreover, treated effluent was employed as dilution medium, contributing to a more environmentally sustainable water management approach for the entire process, at no cost to the culture growth rate. Full article

The three-dimensional flow and mass transfer conditions in 5 L and 40 L airlift oscillation loop reactors were studied and compared with existing two-dimensional simulation and experimental data to verify the accuracy of the method. Then, the fluid dynamics behavior of the 2500 L reactor was simulated via supercomputing and provided guidance for production data. The results indicate that the application of oscillation operation in the 40 L multi-guide tube reactor can effectively improve the gas holdup and mass transfer coefficient in the reactor, with a maximum increase of 38% and 29%. For the 2500 L multi guide tube reactor, oscillation operation oscillation operation can significantly improve gas holdup and mass transfer coefficient increase gas holdup by 46% under 0.5 vvm operating conditions; the mass transfer coefficient increased by 54%. Therefore, oscillation operation can greatly improve the mass transfer coefficient for actual production reactors. After digging a hole in the middle sleeve, the circulating liquid speed has no effect. Although the gas holdup and mass transfer coefficient decreased by 1.3%, the gas holdup inside the entire reactor was more uniform, effectively reducing the average bubble aggregation. Full article

Biosurfactants are surface-active molecules, produced by several microorganisms, that possess unique properties such as low toxicity and biodegradability. Their application in various industries depends on their purity and their specific properties, such as emulsification and stability. Therefore, this study focuses on the production of biosurfactant from Bacillus atrophaeus in an air-lift bioreactor. It analyzes the effects of agitation rate and temperature on biosurfactant production, as well as the concurrent separation process using a foam fractionation column. Moreover, the ability of the produced biosurfactant to form emulsions in water with several substrates (vegetables oils, hydrocarbons, and fossil fuels) was determined, and the stability of the soybean oil–water emulsion (used as an example) at different temperatures and pH values was verified. The biosurfactant produced, tentatively identified as iturin, was only detected in the coalescent liquid after passing through the foam fractionation column, demonstrating the complete separation of the biosurfactant. The best operational conditions for production and separation were an air flow of 1.00 vvm and a temperature of 34 °C (emulsifier index (EI₂₄₎ = 66.9%, and productivity (Pp) = 967.5% mL h⁻¹). Vegetable oils, hydrocarbons, and fossil fuels were emulsified in water, highlighting the soybean oil, whose emulsion oil–water had the highest ES (3333.3 min) at a temperature of 50 °C and a pH value of 9.0. Full article

Rose is a widely favored floriculture crop that is commercially propagated through the application of tissue culture techniques. Here, we report an effective method for axillary shoot proliferation in Al-Taif rose, an important cultivar for rose oil industry. Stem nodes were excised from an adult donor Al-Taif rose shrub and cultured for 4 weeks on Murashige and Skoog’s (MS) medium supplemented with 6-benzylaminopurine (BAP) or gibberellic acid (GA₃) at 0 and 3 mg·L⁻¹ to induce the sprouting of axillary shoots. Al-Taif rose shoots were cultured in vitro for 6 weeks on MS medium fortified with different concentrations of cytokinins, light/dark incubation and different culture types (gelled and liquid/bioreactor culture). The culture conditions that were applied had a noteworthy impact on the responses of Al-Taif rose shoot proliferation. The supplementation of the medium with 6-benzylaminopurine (BAP) resulted in an augmented rate of shoot proliferation in comparison to other cytokinins. Additionally, dark incubation limited foliage growth, leaf yellowing and abscission and favored shoot proliferation compared with light incubation. Liquid culture using bioreactors provided higher axillary shoot proliferation and growth as compared with gelled culture. A continuous immersion system with a net provided the highest axillary shoots (four shoots per explant) and shoot length (16.5 cm), whereas an immersion system without a net provided the highest fresh weight of axillary shoots (499 mg per explant). These findings will improve commercial propagation and contribute to the rose oil industry of Al-Taif rose. Full article

The feasibility of using Garnacha Tintorera bagasse and potato wastes as substrate for the co-production of bacterial cellulose (BC) and gluconic acid by Komagataibacter xylinus fermentation was studied. Firstly, the sulfuric acid hydrolysis of bagasse was evaluated depending on the sulfuric acid concentration (2–4%), temperature (105–125 °C), and time (60–180 min). The bagasse hydrolysates showed a low monosaccharide concentration profile: glucose 3.24–5.40 g/L; cellobiose 0.00–0.48 g/L; arabinose 0.66–1.64 g/L and xylose 3.24–5.40 g/L. However, the hydrolysis treatment enhanced the total phenolic content of the bagasse extract (from 4.39 up to 12.72 mg GAE/g dried bagasse). The monosaccharide profile of the culture medium was improved by the addition of potato residues. From a medium containing bagasse–potato powder (50:50 w/w) and optimal hydrolysate conditions (125 °C for 60 min and 2% H₂SO₄), the composition of glucose increased up to 30.14 g/L. After 8 days of fermentation in an airlift bioreactor by Komagataibacter xylinus, 4 g dried BC/L and 26.41 g gluconic acid/L were obtained with a BC productivity of 0.021 g/L·h, an efficiency of 0.37 g/g and yield of 0.47 g/g. The productivity of gluconic acid was 0.14 g/L·h with an efficiency of 0.93 g/g and yield of 0.72 g/g. This research demonstrates the promising potential of utilizing waste materials, specifically Garnacha Tintorera bagasse and potato residues, as sustainable substrates for the co-production of valuable bioproducts, such as bacterial cellulose and gluconic acid. Full article

Heavy metal contamination of water is a widespread problem in Peru and represents a potential threat to the ecosystem. Bacteria are an ecological alternative to treating these effluents. This research aims to determine the influence of temperature and pH on the lead (Pb) bioremoval in surface water using Serratia marcescens under laboratory conditions. The sample was collected from a stream located in Santiago de Chuco City (Peru). Treatments (T) were carried out by combining pH (5 and 7) and temperature (25, 30, and 35 °C). The bacterial inoculum (S. marcescens) was 3 × 10⁸ CFU/mL, which was constant in all treatments. The lead bioremoval evaluation was performed in an airlift bioreactor and the incubation time was 24 h. The total lead concentration was determined using atomic absorption spectrophotometry. The results show that treatment 6 (temperature: 35 °C, pH: 5, and inoculum: 3 × 10⁸ UFC/mL) showed a better result than the other treatments, with a removal value of 63.94%. Furthermore, the total lead concentration decreased from an initial concentration of 0.268 mg Pb/L to a final value of 0.0964 mg Pb/L. These results are still above the allowed water value (15 µg/L) according to Peruvian standards. On the other hand, temperature and pH influenced lead removal from surface water when S. marcescens was used after a short incubation period (24 h). Although an attempt was made to improve lead bioremoval by varying two parameters, temperature and pH, future research is still needed to investigate the effect of different inoculum concentrations, the use of microbial consortia, and a broader range of physicochemical parameters. Full article

The Zika Virus (ZIKV) is an emerging arbovirus of great public health concern, particularly in the Americas after its last outbreak in 2015. There are still major challenges regarding disease control, and there is no ZIKV vaccine currently approved for human use. Among many different vaccine platforms currently under study, the recombinant envelope protein from Zika Virus (rEZIKV) constitutes an alternative option for vaccine development and has great potential for monitoring ZIKV infection and antibody response. This study describes a method to obtain a bioactive and functional rEZIKV using an E. coli expression system, with the aid of a 5-L airlift bioreactor and following an automated fast protein liquid chromatography (FPLC) protocol, capable of obtaining high yields of approximately 20 mg of recombinant protein per liter of bacterium cultures. The purified rEZIKV presented preserved antigenicity and immunogenicity. Our results show that the use of an airlift bioreactor for the production of rEZIKV is ideal for establishing protocols and further research on ZIKV vaccines bioprocess, representing a promising system for the production of a ZIKV envelope recombinant protein-based vaccine candidate. Full article

Dendrobium loddigesii has long been used in traditional folk medicine. The purpose of this study was to optimize the culture conditions for its protocorm-like bodies (PLBs) and explore their biological activities. The use of an air-lift bioreactor demonstrated superior PLB proliferation compared to agitated and solid culture methods. The optimal inoculum quantity of 30 g/vessel, cultured for 28 days in the bioreactor, yielded the highest PLB biomass production. Analysis of PLB extracts revealed that the ethyl acetate (EtOAc) extract exhibited the highest levels of flavonoids and alkaloids, as well as potent antioxidant activity demonstrated by DPPH free radical scavenging assay and reducing power. Furthermore, the antiproliferative effects of the PLB extracts were assessed using MTT assays, and the EtOAc extract showed significant efficacy by reducing cell viability by over 60% in the human colon carcinoma cell line SW620 at the highest tested concentration (200 μg/mL). Mechanistic analysis revealed the downregulation of key regulatory apoptosis genes, including survivin, p53, caspase-3, and caspase-9. These results demonstrate the potential of the bioreactor culture method for the efficient production of D. loddigesii PLBs and the biological activities of the EtOAc extract, suggesting its therapeutic potential. Full article

Biorefinery systems play a critical role in the transition towards a sustainable bioeconomy, and bioreactors are a key component in these systems. While mechanically stirred reactors have been extensively studied, there is a lack of research on pneumatically driven systems like air-lift reactors (ALRs). This study aims to address this gap by examining the hydrodynamic behavior of a double draft tube airlift bioreactor using Computational fluid dynamics simulations. Ten different geometric configurations were investigated, with variations in draft tube placement, liquid height, distance between draft tubes and draft tube diameters. Results showed that the placement of the draft tubes heavily influenced hydrodynamic behavior, with smaller distances between draft tubes and a funnel configuration leading to higher velocities. Stable downcomer velocities were achieved by maintaining a consistent distance between the bottom clearance and the sum of the distance between draft tubes and the bottom clearance on the top clearance. The model was validated against literature experimental data. This study provides insight into the optimal design of ALRs, which can contribute to the development of more efficient and effective bioreactor systems. The findings can be used to forecast the most optimal configurations of airlift bioreactors and have significant value for the development of more efficient biorefining concepts in light of the increasing importance of studying biorefineries and their components in the shift towards a biomass-based economy. Full article

Red dragon fruit (Hylocereus polyrhizus) is an economic and promising fruit crop in arid and semi-arid regions with water shortage. An automated liquid culture system using bioreactors is a potential tool for micropropagation and large-scale production. In this study, axillary cladode multiplication of H. polyrhizus was assessed using cladode tips and cladode segments in gelled culture versus continuous immersion air-lift bioreactors (with or without a net). Axillary multiplication using cladode segments (6.4 cladodes per explant) was more effective than cladode tip explants (4.5 cladodes per explant) in gelled culture. Compared with gelled culture, continuous immersion bioreactors provided high axillary cladode multiplication (45.9 cladodes per explant) with a higher biomass and length of axillary cladodes. Inoculation of H. polyrhizus micropropagated plantlets with arbuscular mycorrhizal fungi (Gigaspora margarita and Gigaspora albida) significantly increased the vegetative growth during acclimatization. These findings will improve the large-scale propagation of dragon fruit. Full article

This work presents recent developments of algal bioreactors used for CO₂ removal and the factors affecting the reactor performance. The main focus of the study is on light intensity and photoperiods. The role of algae in CO₂ removal, types of algal species used in bioreactors and conventional types of bioreactors including tubular bioreactor, vertical airlift reactor, bubble column reactor, flat panel or plate reactor, stirred tank reactor and specific type bioreactors such as hollow fibre membrane and disk photobioreactors etc. are discussed in details with respect to utilization of light. The effects of light intensity, light incident, photoinhibition, light provision arrangements and photoperiod on the performance of algal bioreactors for CO₂ removal are also discussed. Efficient operation of algal photobioreactors cannot be achieved without the improvement in the utilization of incident light intensity and photoperiods. The readers may find this article has a much broader significance as algae is not only limited to removal or sequestration of CO₂ but also it is used in a number of commercial applications including in energy (biofuel), nutritional and food sectors. Full article

Ageratina pichinchensis (Kunth) R.King & Ho.Rob. is a plant used in traditional Mexican medicine, and some biotechnological studies have shown that its calluses and cell suspension cultures can produce important anti-inflammatory compounds. In this study, we established a cell culture of A. pichinchensis in a 2 L airlift bioreactor and evaluated the production of the anti-inflammatory compounds 2,3-dihydrobenzofuran (1) and 3-epilupeol (2). The maximum biomass production (11.90 ± 2.48 g/L) was reached at 11 days of culture and cell viability was between 80% and 90%. Among kinetic parameters, the specific growth rate (µ) was 0.2216 days⁻¹ and doubling time (td) was 3.13 days. Gas chromatography coupled with mass spectrometry (GC-MS) analysis of extracts showed the maximum production of compound 1 (903.02 ± 41.06 µg/g extract) and compound 2 (561.63 ± 10.63 µg/g extract) at 7 and 14 days, respectively. This study stands out for the significant production of 2,3-dihydrobenzofuran and 3-epilupeol and by the significant reduction in production time compared to callus and cell suspension cultures, previously reported. To date, these compounds have not been found in the wild plant, i.e., its production has only been reported in cell cultures of A. pichinchensis. Therefore, plant cell cultured in an airlift reactor can be an alternative for the improved production of these anti-inflammatory compounds. Full article