Feed Medium Research Articles

How efficiently does a metabolically enhanced system with denitrifying anaerobic methane oxidizing microorganisms remove antibiotics?

In this work, the novel N-damo (Nitrite dependent anaerobic methane oxidation) process was investigated at high biomass activities for its potential to remove simultaneously nitrite and methane, as well as selected antibiotics commonly found in sewage in trace amounts. For this purpose, two MBRs were operated at three high nitrite loading rates (NLRs), namely 76 ± 9.9, 161.5 ± 11.4 and 215.2 ± 24.2 mg N–NO⁻2 L−1 d−1, at long-term operation. The MBRs performance achieved a significantly high nitrite removal activity for an N-damo process (specific denitrifying activity of up to 540 mg N–NO⁻2 g−1 VSS d−1), even comparable to heterotrophic denitrification values. In this study, we have implemented a novel operational strategy that sets our work apart from previous studies with similar bioreactors. Specifically, we have introduced Cerium as a trace element in the feeding medium, which serves as a key differentiating factor. It allowed maintaining a stable reactor operation at high NLRs. Microbial community composition evidenced that both MBRs were dominated with N-damo bacteria (67–87% relative abundance in period III and I, respectively). However, a decrease in functional N-damo bacteria (Candidatus Methylomirabilis) abundance was observed during the increase in biomass activity and concentration, concomitantly with an increase of the other minor families (Hypomicrobiaceae and Xanthobacteraceae). Most of the selected antibiotics showed high biotransformation such as sulfamethoxazole, trimethoprim, cefalexin and azithromycin, whereas others such as roxithromycin and clarithromycin were only partially degraded (20–35%). On the contrary, ciprofloxacin showed almost no removal. Despite the metabolic enhancement, no apparent increase on the antibiotic removal was observed throughout the operation, suggesting that microbiological composition was of greater influence than its primary metabolic activity on the removal of antibiotics.

Parametric optimization of Sm(III) extraction from nitrate media by employing hollow fiber membrane using Taguchi analysis

ABSTRACT The present work elaborates studies on samarium (Sm) extraction and transport behavior from aqueous stream by employing hollow fiber membrane. Percentage extraction and percentage transport of Sm(III) have been investigated under wide range of experimental parameters such as type of organic extractant, concentration of organic extractant, aqueous phase acidity, flow rate in the module, strip phase acidity and metal ion concentration. Taguchi method utilizing L-18 orthogonal array has been adopted to identify the most influential process parameters responsible for higher degree of extraction and transport of Sm(III) from nitric acid feed medium. A total of 18 experimental runs (each repeated thrice) were carried out under the combination derived from Taguchi array. In Taguchi analysis, the extraction of Sm(III) ions was directed into a precise signal-to-noise ratio for a “high is better” response. Analysis of variance indicated that the selection of organic extractant is the most influential factor controlling extraction and transport, followed by aqueous phase acidity. The experiment performed under the optimum conditions as predicted by Taguchi method resulted in 99.9% extraction of Sm(III) from the feed solution and 98.8% transport of Sm(III) across the membrane with minimum standard deviation.

The role of roughness parameters in grading the machined surface quality in Ti-alloys

Titanium alloys are extensively employed in machining to produce high-value components, where surface roughness is crucial for their functionality. In this study, the roughness of Ti6Al4V and Ti6Al7Nb turned surfaces was analysed. The goal was to compare the alloy’s roughness behaviour when machined under the same conditions. Therefore, hypothesis testing was performed to assess the equality of the expected values and population median. It was found that, for some parameters, the mean ( RzI, Rt) and median ( Rq, RzD, Pt) roughness was statistically different when changing alloys. However, for others, it did not present a significant difference, in terms of mean ( RmD, Rp) and median ( Ra, Rpm). Consequently, a relevant insight from this study was that the phenomenon interpretation was affected by roughness parameter selection. On the other hand, as expected, the feed rate played a critical role in roughness control. It was observed that Ti6Al7Nb had a smoother topography ( Ra was 0.15 ± 0.01 μm and 0.62 ± 0.04 μm) than Ti6Al4V (0.31 ± 0.02 μm and 0.67 ± 0.03 μm) at 0.05 and 0.15 mm/rev. Yet, at 0.1 mm/rev, this behaviour changed, as Ti6Al4V had a smoother surface ( Ra was 0.40 ± 0.02 μm) than Ti6Al7Nb ( Ra was 0.51 ± 0.03 μm). Finally, the multi-optimization indicated that a low feed rate (0.05 mm/rev) and medium (60 m/min) and high (90 m/min) cutting speed led to lower roughness and higher material removal rate for turning Ti6Al7Nb and Ti6Al7V, respectively. The insights from this study may have a practical application in the manufacturing and quality control of biomedical components.

Process engineering towards an oxidative cellular state improves 3-hydroxypropionic acid production with Lentilactobacillus diolivorans

3-hydroxypropionic acid (3-HP) is among the top platform chemicals proposed for bio based production by microbial fermentation from renewable resources. A promising renewable substrate for 3-HP production is crude glycerol. Only a few microorganisms can efficiently convert glycerol to 3-HP. Among the most promising organisms is Lentilactobacillus diolivorans. In this study, an already established fed-batch process, accumulating 28 g/L 3-HP, was used as a starting point for process engineering. The engineering approaches focused on modulating the cellular redox household towards a more oxidized state, as these conditions favour 3-HP production. Variations of oxygen and glucose availability (controlled by the glucose/glycerol ratio in the feed medium) individually already improved 3-HP production. However, the combination of both optimal parameters (30% O2, 0.025 mol/mol glu/gly) led to the production of 67.7 g/L 3-HP after 180 h of cultivation, which is so far the highest titer reported for 3-HP production using Lactobacillus spp.

Addressing amino acid-derived inhibitory metabolites and enhancing CHO cell culture performance through DOE-guided media modifications.

Previously, we identified six inhibitory metabolites (IMs) accumulating in Chinese hamster ovary (CHO) cultures using AMBIC 1.0 community reference medium that negatively impacted culture performance. The goal of the current study was to modify the medium to control IM accumulation through design of experiments (DOE). Initial over-supplementation of precursor amino acids (AAs) by 100% to 200% in the culture medium revealed positive correlations between initial AA concentrations and IM levels. A screening design identified 5 AA targets, Lys, Ile, Trp, Leu, Arg, as key contributors to IMs. Response surface design analysis was used to reduce initial AA levels between 13% and 33%, and these were then evaluated in batch and fed-batch cultures. Lowering AAs in basal and feed medium and reducing feed rate from 10% to 5% reduced inhibitory metabolites HICA and NAP by up to 50%, MSA by 30%, and CMP by 15%. These reductions were accompanied by a 13% to 40% improvement in peak viable cell densities and 7% to 50% enhancement in IgG production in batch and fed-batch processes, respectively. This study demonstrates the value of tuning specific AA levels in reference basal and feed media using statistical design methodologies to lower problematic IMs.

Methods for identifying precipitates and improving stability of chemically defined highly concentrated cell culture media.

Currently, within the biopharmaceutical industry, media development is a key area of development as the ratios and concentrations of media components such as amino acids, metals, vitamins, sugars, salts, and buffering agents play arguably the largest role in cellular productivity and product quality. However, optimizing media for these targets often conflicts with solubility limitations and slow-rate chemical reactions that result in precipitation formation. Here we present methods such as inductively coupled plasma mass spectrometry (ICP-MS), X-ray fluorescence (XRF), colorimetry, and turbidity to identify multiple likely components of a complex precipitate that was observed in preparations of a custom nutrient feed medium across all storage conditions evaluated. Using these analytical methods, as well as adjustments to the formulation pH, increasing the pyruvate concentration, and removing sodium bicarbonate, we were able to extend the media shelf life from approximately 10 days to over 28 days. Alternatively, copper, selenium, and magnesium sources were removed from the media and no precipitation was observed until 32 days after prep, pointing to key metals as the probable root cause of precipitation. By analytically quantifying the precipitate using the methods above, instead of visual inspection, which is the current industry standard for media precipitation observation, we were better able to compare conditions to one another and relate them to the onset of precipitation. Cell culture performance and product quality remained comparable to the historical process despite the media formulation changes.

Kualitas Fisik dan Kimiawi Maggot BSF yang Dibudidaya Oleh Peternak Menggunakan Media Pakan yang Berbeda

This study aims to determine the physical and chemical quality of maggot cultivated by farmers on the island of Lombok using different feed media. The research was conducted in 2 tages, namely: Phase I. Observation of 5 locations of maggot farms on Lombok Island with a production scale of at least 5 kg per week. The parameters observed were the type of feed used, production scale, body weight and body length of maggot per head. Stage II. Analisis of the nutritional quality of feed and maggot media using the Proximate analysis method. Parameters observed were water content, ash content, crude protein, crude fat, and crude fiber. The data collected were tabulated and discussed descriptively. The results showed that there were 4 TPS locations and 1 quail farm location which was assisted with maggot cultivation with a maggot production scale of 7-350 kg per week. The lowest production scale is at the location of the quail farm using quail manure and the highest scale is at the TPS location Ds. Sengkol using kitchen waste as feed media, expired milk, coconut dregs, and banan stems. The protein content of the feed media that had been converted by maggot ranged from 4.51-24.64% and the maggot content produced ranged from 23.0-42.45%, the highest at quail Farm Puyung village which uses quail waste media. The conclusion of this study that the use of quail waste media as a feed medium resulted in the best quality of maggot.

Fed-batch culture of Oplopanax elatus adventitious roots: Establishment of a complete culture system

Fed-batch culture is rarely applied in plant organ culture, but it has been attempted to be used in Oplopanax elatus adventitious root (AR) culture. To establish a complete fed-batch O. elatus AR culture system, this study investigated the effects of sucrose, phosphorus, and nitrogen concentrations in the initial medium, and feeding time, feeding volume, and harvest time on AR biomass and flavonoid or polysaccharide accumulation. The results indicated the initial medium (3 L) containing 0.938 mM phosphorus and 40 mM nitrogen supplemented with 40 g/L sucrose, feeding with 2 L feeding medium on the 15th day, and harvesting on the 45th day were the most suitable conditions for the production of flavonoid- and polysaccharide-enriched ARs. In the established culture system, 76.7 mg/L/day of flavonoids and 200.9 mg/L/day of polysaccharides were obtained. This study suggested that fed-batch culture is a promising approach for mass production of O. elatus ARs.

Perspectives of computational fluid dynamics methods in the study of membrane processes

In mathematical modeling of membrane processes, the study of structural features of used membranes and the significant limitation of information in the formal description of their separation properties led to the development of physical models that take into account not only the features of structures of real membranes, but also their peculiarities of functioning. When compiling physical models of membrane processes, it is impossible to objectively quantify most of the factors due to their great diversity and variability, which distances the mathematical model from the real process. That is why methods of computational fluid dynamics reliably and efficiently perform calculations for all physical models and types, including stationary or transient flow, incompressible or compressible flow (from small subsonic to hypersonic), simulation of laminar or turbulent flows, Newtonian or non-Newtonian fluids, ideal or real gas. An electronic geometric model of the plant was built, a choice of mesh geometry with different densities was made to optimize the calculation time and solution accuracy for a particular case, the kinetic dependence of cell growth was calculated, the flow rates of feeding medium into the intra- and inter-fiber spaces of the bioreactor were determined, and the hydrodynamic conditions were analyzed.

Impact of age on the rotenone-induced sporadic Parkinson's disease model using Drosophila melanogaster

Rotenone, a naturally occurring toxin, has been used to induce sporadic Parkinson's disease (PD) in Drosophila melanogaster for decades. However, the age of flies varies considerably between studies in this model. To investigate the impact of age on the rotenone-induced PD model, we collected male flies at the age of 1, 5, 7, and 10 days post-eclosion, respectively. Then, flies were immediately exposed to a feeding medium supplemented with 250 μM rotenone for seven days. The motor ability of Drosophila was detected by negative geotaxis assay, and the number of dopamine (DA) neurons and tyrosine hydroxylase (TH) expression levels were evaluated. The results showed that both the motor deficits and mortality increased with age. The flies older than five days showed typical PD features, including the loss of DA neurons, decreased TH expression levels, and decreased locomotive ability. However, 1-day-old flies displayed an unstable motor deficit and little TH expression changes after seven days of rotenone exposure. Lastly, after 7 days of exposure to rotenone, the death rate of flies rapidly increased with increasing starting age. The death rates of 1-, 5-, 7-, and 10-days old flies were 10.0%, 22.8%, 41.5%, and 50.4%, respectively. The findings of this study suggest that age is a crucial factor impacting the Drosophila PD model. This information provides a reference for the age selection to use this model for future studies.

Household Waste Management As a Medium for Maggot Cultivation in Resun villages

This community service program was carried out in Resun Village, North Lingga District, Lingga Regency. The waste problem in Resun Village, North Lingga District, Lingga Regency, has been a problem that has been born for a long time and has not received maximum treatment due to the lack of facilities and infrastructure. This internship activity resulted in a program after observations for some time, namely socialization about waste management, a waste sorting program from home, and also a maggot cultivation program with the use of organic waste as a feed medium. The purpose of the socialization of this maggot cultivation program is to provide solutions to reduce waste accumulation and make waste more useful. Socialization of the maggot (Hermetia illucens) cultivation program to the community in Resun Village, North Lingga District, Lingga Regency, Riau Islands Province.

Progress in fed-batch culture for recombinant protein production in CHO cells.

Nearly 80% of the approved human therapeutic antibodies are produced by Chinese Hamster Ovary (CHO) cells. To achieve better cell growth and high-yield recombinant protein, fed-batch culture is typically used for recombinant protein production in CHO cells. According to the demand of nutrients consumption, feed medium containing multiple components in cell culture can affect the characteristics of cell growth and improve the yield and quality of recombinant protein. Fed-batch optimization should have a connection with comprehensive factors such as culture environmental parameters, feed composition, and feeding strategy. At present, process intensification (PI) is explored to maintain production flexible and meet forthcoming demands of biotherapeutics process. Here, CHO cell culture, feed composition in fed-batch culture, fed-batch culture environmental parameters, feeding strategies, metabolic byproducts in fed-batch culture, chemostat cultivation, and the intensified fed-batch are reviewed. KEY POINTS: • Fed-batch culture in CHO cells is reviewed. • Fed-batch has become a common technology for recombinant protein production. • Fed batch culture promotes recombinant protein production in CHO cells.

In vitro mass reproduction of parasitic entomophages (Braconidae, Trichogrammatidae)

The issue of propagating parasitic insects in artificial food environments has been a challenge for researchers for a long time. Breeding one Trichogramma insect requires a lot of grain products and labor, and it takes about 40-50 days for Trichogramma and 55-60 days for Bracon to reproduce. This study aimed to develop a technology for the in vitro reproduction of trichogram, which are important parasitic entomophages in the control of various agricultural pests. The results of the experiments showed that the Trichogramma chilonis damage to nests with offspring was 82.4%, larvae emerged from eggs in 1.7 days. The larvae developed in this nutrient medium for 5.0 days, and the pupation period was 4.5 days. The average time from egg to imago was 11.2 days. The survival of hatchlings from the feeding medium lasted 5.4 days, and the male:female ratio (♂:♀) of hatched Trichograms was 1:6.

Insect vectors of phytoplasmas in soybean fields: Discovery of Recilia dorsalis and Exitianus indicus through feeding medium assay

Insect vectors of phytoplasmas in soybean fields: Discovery of Recilia dorsalis and Exitianus indicus through feeding medium assay

Effect of Feeding Kiwifruit (Actinidia deliciosa) Extract on Survival Rate and Reproductive Organ Morphology of Fruit Fly (Drosophila melanogaster Meigen, 1830) Ultraviolet Light Irradiation

UV (ultraviolet) radiation is one of the radiations that are naturally emitted by the sun. As the result of climate changes, the earth's ozone layer changes and the UV light radiation to the earth's surface increases. The negative effect of UV radiation is increase due to the production of ROS (Reactive Oxygen Species) or free radicals in the body. UV radiation protection can be done by increasing the intake of antioxidant-rich foods as free radical inhibitors. Actinidia deliciosa or kiwifruit is a antioxidants-rich fruit including vitamin C. This research was carried out with Drosophila melanogaster as a animal model because it is easy to breed in the laboratory, has a short life cycle, and produces large numbers of eggs. Drosophila melanogaster or fruit flies are the most commonly used of animal models in the biomedical and pharmacological fields. This study aims to determine the effect of UV radiation on fruit fly survival at the larval, pupa, and imago stages and the morphology changes of male and female reproductive organs, as well as to determine the effect of feeding kiwi fruit extract on survival rate and morphology changes of male and female reproductive organs of UV irradiated fruit fly. This research was conducted by providing UV exposure treatment and without UV radiation treatment to fruit flies for 2 hours on banana and kiwi feed medium. Data analysis was carried out with the One Way Anova test followed by the Duncan test. The results showed that UV radiation could affect the survival and morphology of the reproductive organs of fruit flies. The survival rate in the control treatment was 58%, PK treatment 81%, PPUV treatment 45%, and PKUV treatment 47%.

Acetate augmentation boosts the ethanol production rate and specificity by Clostridium ljungdahlii during gas fermentation with pure carbon monoxide

Recycling waste gases from industry is vital for the transition toward a circular economy. The model microbe Clostridium ljungdahlii reduces carbon from syngas and primarily produces acetate and ethanol. Here, a gas fermentation experiment is presented in chemostats with C. ljungdahlii and pure carbon monoxide (CO) as feedstock while entirely omitting yeast extract. A maximum ethanol production rate of 0.07 ± 0.01 g L−1 h−1 and a maximum average ethanol/acetate ratio of 1.41 ± 0.39 was observed under steady-state conditions. This confirmed that CO as the sole feedstock pushes the metabolism toward more reduced fermentation products. This effect was even more pronounced when 15 mM sodium acetate was added to the feed medium. An ethanol production rate of 0.23 ± 0.01 g L−1 h−1 was achieved, representing an increase of more than 240%. This increase was accompanied by an increase in cell density and selectivity toward ethanol, with a maximum average ethanol/acetate ratio of 92.96 ± 28.39. Oxygen contaminations voided this effect, although the cultures were still able to maintain a stable biomass concentration and ethanol production rate. These findings highlight the potential of CO-fermentation with acetate augmentation and the importance of preventing oxygen contaminations.

Multi-objective optimal control of bioconversion process considering system sensitivity and control variation

This paper aims to determine a time-varying dilution rate of the feed medium which maximizes mean productivity while minimizing both system sensitivity and control cost in glycerol continuous culture. A multi-objective optimal control problem subjected to a nonlinear control system and its auxiliary system is proposed and transformed into a finite-dimensional large-scale multi-objective optimization problem via discretization and time-scaling transformation. A multi-objective competitive swarm optimization algorithm is constructed to solve this transformed problem based on pairwise competition, mutation operation and environment selection. The Pareto front obtained shows the distribution of the optimal target value which indicates the rationality and feasibility of the control system under the approximate optimal strategy. Numerical simulations verify the robustness of the optimal control system and the effectiveness of our numerical solution method. The value of IGD shows the good accuracy and distribution of the proposed multi-objective optimization algorithm.

High-rate continuous n-butanol production by Clostridium acetobutylicum from glucose and butyric acid in a single-pass fibrous-bed bioreactor.

Biobutanol produced in acetone-butanol-ethanol (ABE) fermentation at batch mode cannot compete with chemically derived butanol because of the low reactor productivity. Continuous fermentation can dramatically enhance productivity and lower capital and operating costs, but are rarely used in industrial fermentation because of increased risks of culture degeneration, cell washout, and contamination. In this study, cells of the asporogenous Clostridium acetobutylicum ATCC55025 were immobilized in a single-passfibrous-bed bioreactor (FBB) for continuous production of butanol from glucose and butyrate at various dilution rates. Butyric acid in the feed medium helped maintaining cells in the solventogenic phase for stable continuous butanol production. At a dilution rate of 1.88 h-1 , butanol was produced at 9.55 g/L, with a yield of 0.24 g/g and productivity of 16.8 g/L/h, which was the highest productivity ever achieved for biobutanol fermentation and an 80-fold improvement over the conventional ABE fermentation. The extremely high productivity was attributed to the high density of viable cells (~100 g/L at >70% viability) immobilized in the fibrous matrix, which also enabled the cells to better tolerate butanol and butyric acid. The FBB was stable for continuous operation for an extended period of over 1 month.

Lactic Acid Production from Old Oil Palm Trunk Sap in the Open Batch, Open Repeated Batch, Fed-Batch, and Repeated Fed-Batch Fermentation by Lactobacillus rhamnosus ATCC 10863

The cost of fermentable sugars added as a substrate is one major problem for economic lactic acid (LA) production. Old oil palm trunks (OPT) squeezed sap, the agricultural wastes on replanting and pruning of oil palm (Elaeis guineensis), contained mainly glucose and fructose as a potential feedstock to use as a vast carbon source for LA production. To improve the LA yield and productivity, various fermentation modes were performed by Lactobacillus rhamnosus ATCC 10863 using OPT sap as a basal medium. A modified constant feed mode of fed-batch and repeated fed-batch fermentation using undiluted OPT sap feed medium can achieve a high average LA concentration of 95.94 g/L, yield of 1.04 g/g, and productivity of 6.40 g/L/h) at 11 h cultivation time. It can also provide open and open repeated batch fermentation with an average LA concentration of 91.30 g/L, yield of 0.87 g/g, and productivity of 3.88 g/L/h at 21 h fermentation time.

Highly efficient fed-batch modes for enzymatic hydrolysis and microbial lipogenesis from alkaline organosolv pretreated corn stover for biodiesel production

High-density culture for microbial lipid preparation from low-cost lignocellulosic feedstocks is crucial for commercial-scale biodiesel production. Herein, fed-batch saccharification of alkaline organosolv pretreatment (AOP) of corn stover at an extremely high solids content of 47% (w/v) released 299.5 g/L of lignocellulosic sugars including 18.3% of soluble oligosaccharides. Three types of liquid hydrolysates for seed culture, fermentation, and feeding during fed-batch culture were obtained from the hydrolysate slurry using a two-step washing strategy with 99.3% of sugars recovery. Cutaneotrichosporon oleaginosum showed excellent capacity for assimilating both monosaccharides and oligosaccharides for lipid production using the fed-batch culture mode. Lipid concentration, content, and yield gained 42.3 g/L, 64.6%, and 20.4 g/100 g, respectively. Turbid hydrolysate collected with high recovery of high-concentration sugars and simplified process could be directly served as feeding medium. In general, the overall hydrolysis yield and lipid yield using fed-batch mode accounted for 93.2% and 97.6% of those using batch mode, respectively, resulting in a lipid output of 102.8 g/kg raw corn stover. The fatty acid composition and the prediction of biodiesel properties of lipid samples indicated the suitability for high-quality fuel production. This study provided valuable information for designing highly efficient lignocelluloses-to-biodiesel routes.