Expensive Media Research Articles

Utility of Extraction-Free SARS-CoV-2 Detection by RT-qPCR for COVID-19 Testing in a Resource-Limited Setting.

The COVID-19 epidemic had a profound impact on global health and the economy and Ghana was no exception to its far-reaching consequences. Regarding detection of the causative agent-the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), reverse-transcription-qPCR (RT-qPCR) is widely recognized as a very sensitive and reliable diagnostic technique used globally. There are, however, high operational costs in acquiring test kits, equipment, and accessories for RT-qPCR testing, which pose significant challenges in resource-limited settings. Hence, this proof-of-concept study set out to develop a more affordable COVID-19 protocol for use in low or lower-middle-income settings, such as Ghana, that would bypass the traditional extraction process using inexpensive reagents and evaluate the possibility of processing samples collected using wooden shaft swabs. Several less expensive media were used for the extraction-free process. Results demonstrated that direct RT-qPCR assay after 5 min heat inactivation of virus at 95 °C in 0.1× PBS or molecular grade water resulted in viral detection with quantification cycle (Cq) values that are comparable to results obtained following the extraction process. Also, wooden shaft swabs could be used for sampling if incubation times are kept to less than 6 h. The study demonstrates that extraction-free protocols are one way to minimize the cost of COVID-19 testing by RT-qPCR.

Biofloc wastewater for microalgae (Chlorella ellipsoidea) production: an approach to algal biomass production and nutrient remediation

ABSTRACT Bold Basal Medium (BBM) is a standard but expensive medium for Chlorella ellipsoidea culture. This study evaluated the effect of biofloc wastewater (BWW) on the growth and pigment content of C. ellipsoidea and also investigated its bioremediation potential. The experiment was conducted for 24 d in five treatments, each with three replications. BBM was replaced with BWW at 0, 25, 50, 75, and 100% levels and considered as control (0% BWW), 25% BWW, 50% BWW, 75% BWW, and 100% BWW treatment, respectively. During the exponential period, the cell dry weight, optical density, cell density, specific growth rate, chlorophyll a, b, and β-carotene content were significantly (P ˂ 0.05) higher in 75% BWW treatment, which was followed by 0% BWW, 50% BWW, 100% BWW, and 25% BWW, correspondingly. NH3, NO2, and PO4 recovery efficiency were also higher in 75% BWW treatment. Therefore, the study proves that 75% BWW has the potential to culture C. ellipsoidea as an alternative to expensive BBM along with nutrient recovery from BWW.

Modelling, analysis and validation of a dynamic dense medium separation circuit model for detecting medium losses

Dense medium separation circuits use a dense medium to separate low density waste material from high density valuable minerals. Since the dense medium is an expensive consumable, it is recovered after separation of the valuable minerals from waste. A dynamic nonlinear model of a dense medium separation circuit of an iron ore plant in South Africa is developed to track the flow of medium in the circuit. An extended Kalman filter is designed for estimating observable but unmeasured states. The model is validated using online plant data. This paper serves as a precursor for further work to detect and mitigate expensive medium losses in the circuit.

Itaconate Production from Crude Substrates with U. maydis: Scale-up of an Industrially Relevant Bioprocess

BackgroundIndustrial by-products accrue in most agricultural or food-related production processes, but additional value chains have already been established for many of them. Crude glycerol has a 60% lower market value than commercial glucose, as large quantities are produced in the biodiesel industry, but its valorisation is still underutilized. Due to its high carbon content and the natural ability of many microorganisms to metabolise it, microbial upcycling is a suitable option for this waste product.ResultsIn this work, the use of crude glycerol for the production of the value-added compound itaconate is demonstrated using the smut fungus Ustilago maydis. Starting with a highly engineered strain, itaconate production from an industrial glycerol waste stream was quickly established on a small scale, and the resulting yields were already competitive with processes using commercial sugars. Adaptive laboratory evolution resulted in an evolved strain with a 72% increased growth rate on glycerol. In the subsequent development and optimisation of a fed-batch process on a 1.5-2 L scale, the use of molasses, a side stream of sugar beet processing, eliminated the need for other expensive media components such as nitrogen or vitamins for biomass growth. The optimised process was scaled up to 150 L, achieving an overall titre of 72 g L− 1, a yield of 0.34 g g− 1, and a productivity of 0.54 g L− 1 h− 1.ConclusionsPilot-scale itaconate production from the complementary waste streams molasses and glycerol has been successfully established. In addition to achieving competitive performance indicators, the proposed dual feedstock strategy offers lower process costs and carbon footprint for the production of bio-based itaconate.

Bioconversion of waste glycerol into viscosinamide by Pseudomonas fluorescens DR54 and its activity evaluation

Lipopeptides, derived from microorganisms, are promising surface-active compounds known as biosurfactants. However, the high production costs of biosurfactants, associated with expensive culture media and purification processes, limit widespread industrial application. To enhance the sustainability of biosurfactant production, researchers have explored cost-effective substrates. In this study, crude glycerol was evaluated as a promising and economical carbon source in viscosinamide production by Pseudomonas fluorescens DR54. Optimization studies using the Box − Behnken design and response surface methodology were performed. Optimal conditions for viscosinamide production including glycerol 70.8 g/L, leucine 2.7 g/L, phosphate 3.7 g/L, and urea 9.3 g/L were identified. Yield of viscosinamide production, performed under optimal conditions, reached 7.18 ± 0.17 g/L. Preliminary characterization of viscosinamide involved the measurement of surface tension. The critical micelle concentration of lipopeptide was determined to be 5 mg/L. Furthermore, the interactions between the viscosinamide and lipase from Candida rugosa (CRL) were investigated by evaluating the impact of viscosinamide on lipase activity and measuring circular dichroism. It was observed that the α-helicity of CRL increases with increasing viscosinamide concentration, while the random coil structure decreases.

Investigations on riboflavin production by wild-type yeast strain for supplementation of organic feed

Supplementation of vitamin B2 (riboflavin) in poultry feeding is essential. For economic and environmental reasons, riboflavin is now produced biotechnologically, which, in most industrial production, is based on genetically modified organisms (GMOs). Due to legislation, organic animals must be fed with GMO-free feeds, which also applies to the production processes of vitamin additives in the feed. Therefore, the main objective of experiments in this paper is the screening of GMO-free wild-type yeast strains overproducing riboflavin as a starting point to develop GMO-free riboflavin production lines that ensure the continuous supply of riboflavin for organic livestock. A screening of wild-type, non-GMO microorganisms overproducing riboflavin was conducted. The wild-type yeast Meyerozyma guilliermondii DSM 11947 produced the highest riboflavin concentration in the screening procedure. In order to provide a feasible and affordable certified organic animal vitamin B2 supplement, the possibility of minimizing the expensive media component, yeast extract, was shown. This work shows the possibility of using a wild-type strain to achieve higher levels of riboflavin by means of bioprocess engineering and without metabolic engineering. A fermentation strategy at the laboratory scale is provided, where a yield of 30 mg riboflavin per g dry matter of yeast cells was achieved.

Evaluation of corn steep liquor as fermentation media for recombinant Lactococcus lactis producing antifreeze proteins.

Corn processing byproducts corn steep liquor (CSL), and thin stillage were evaluated as growth media for recombinant Lactococcus lactis modified to produce antifreeze proteins (AFPs) that could have important food and non-food applications. The AFP III sequence from ocean pout was cloned into a shuttle vector to make an expression vector that facilitated the production of recombinant AFP III in Lactococcus lactis. Light CSL from yellow dent corn and thin stillage from the industrial corn bioethanol process were optimized as fermentation media with a combination of the following additives and trace elements: disodium-β-glycerophosphate (DG), tryptone (T), ascorbic acid (AA), iron (Fe), zinc (Zn), and magnesium (Mg). The growth of wild-type and recombinant Lactococcus lactis strains were compared over a 72 h period in 96-well plates and 250 mL shake flasks. The corn coproducts media consisting of 50% (v/v) light steep in water supplemented with DG-5g L-1 , T-5g L-1 , AA-0.5g L-1 , and Zn-4ppm resulted in best growth and was considered as the best-optimized media. The addition of additives and trace elements better supported the growth of both wild-type and recombinant Lactococcus lactis strains compared to control media without any additives. Respective fermentation supernatants were frozen to -20 °C, and the time to supercool and freeze was compared. A distinct supercooling effect was observed for the supernatants from recombinant strains thus, extending the time and temperature of supercooling and freezing. The maximum time of supercooling extended was 17.55 ± 4.45 min for thin stillage followed by M17 media (17.25 ± 4.45 min), Kent Corporation CSL (10.80 ± 2.12 min), and yellow dent CSL (6.9 ± 0.85 min) when fermented with recombinant Lactococcus lactis strains. The supplemented corn coproduct-based media enhanced the growth of both wild-type and recombinant Lactococcus lactis strains. These optimized media can replace or supplement more expensive media (e.g. M17), potentially reducing cost. The fermentation supernatants exhibited longer times to supercool, and freeze compared to control supernatants, indicating potential use as antifreeze compounds in frozen food and non-food applications. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Low-cost Media from Agro-industrial Wastes for the Cultivation and Metabolite Production of Lactic Acid Bacteria

Lactic acid bacteria (LAB) are the most well-documented, “generally regarded as safe” microorganisms used in food fermentation, cosmetics, and pharmaceuticals. Many probiotic strains are utilized for the production of beneficial metabolites, such as bacteriocins and lactic acid, which influence the preservation, organoleptic characteristics, and nutritional properties of food. However, these strains are usually cultured using complex and expensive media, which significantly contribute to the cost of the final product. Thus, this study aims to develop a low-cost alternative medium (LCAM) for the growth and metabolite production of industrially important LAB strains. After several preliminary experiments, an LCAM containing rice bran extract, waste coconut (mature) water, baker’s yeast extract, table sugar, and salts was subjected to a statistically-guided optimization study for growth support of a model LAB strain Lactobacillus plantarum BS. Based on the second-order response mathematical model, the optimized medium composition was 35% rice bran extract and 58% waste coconut water, 1% baker’s yeast extract, 1% table sugar, and 5% salt solution (LCAM A) plus a modified version without baker’s yeast and table sugar (LCAM B). Predicted values were acceptable at 95% (8.91 and 8.88 log CFU/mL) and highly comparable (102% relativity) with the commercial complex medium used as control. Both LCAM formulations were found to support the growth and metabolite production of different LAB genera (L. plantarum BS, Lactococcus lactis NCDO 497, Enterococcus faecalis M4-3, Streptococcus thermophilus BIOTECH 1555, and Pediococcus acidilactici BIOTECH 1068). The LCAM supported the metabolite production of these LAB strains comparable with the commercial medium but is 7.4–7.6-fold cheaper than the cheapest commercial medium. This significant cost reduction has a huge prospect on the large-scale utilization of LAB. Nevertheless, further studies are necessary to enhance the nutritive composition of LCAM for other genera of LAB.

Microsensor in Microbioreactors: Full Bioprocess Characterization in a Novel Capillary-Wave Microbioreactor.

Microbioreactors (MBRs) with a volume below 1 mL are promising alternatives to established cultivation platforms such as shake flasks, lab-scale bioreactors and microtiter plates. Their main advantages are simple automatization and parallelization and the saving of expensive media components and test substances. These advantages are particularly pronounced in small-scale MBRs with a volume below 10 µL. However, most described small-scale MBRs are lacking in process information from integrated sensors due to limited space and sensor technology. Therefore, a novel capillary-wave microbioreactor (cwMBR) with a volume of only 7 µL has the potential to close this gap, as it combines a small volume with integrated sensors for biomass, pH, dissolved oxygen (DO) and glucose concentration. In the cwMBR, pH and DO are measured by established luminescent optical sensors on the bottom of the cwMBR. The novel glucose sensor is based on a modified oxygen sensor, which measures the oxygen uptake of glucose oxidase (GOx) in the presence of glucose up to a concentration of 15 mM. Furthermore, absorbance measurement allows biomass determination. The optical sensors enabled the characterization of an Escherichia coli batch cultivation over 8 h in the cwMBR as proof of concept for further bioprocesses. Hence, the cwMBR with integrated optical sensors has the potential for a wide range of microscale bioprocesses, including cell-based assays, screening applications and process development.

Sand amended with carbonised rice husk and goat manure as a propagation medium

Abstract Tomato is an important horticultural crop as it provides income and contributes to food security for Rwandan citizens. Besides its importance, its production is hampered by the use of a soil-based growing medium which results in the production of low-quality transplants. This is mainly attributed to the unaffordability of peat moss to small-scale farmers in Rwanda. Hence, a greenhouse nursery experiment was carried out at the Rwanda-Israel Horticulture Centre of Excellence to search for an alternative growing medium to peat moss. Nine different growing media were formulated from a mixture at different ratios of sand, goat manure, and carbonised rice husks. The seeds were sown in propagation trays. The experiment was laid out in a randomised complete block design (RCBD) with four replications. Data obtained were subjected to analysis of variance and means were separated using Tukey’s honestly significant difference test at p ≤ 0.05. The data analysis was carried out using SAS software version 9.2. The results revealed that sand + goat manure + carbonised rice husk 50 %: 10 %: 40 % (T8) was comparable to T1 (peat moss 100 %) in producing higher quality seedlings during both trials with a mean quality index of 0.28 and 0.31, respectively, whereas T2 (sand 100 %) had seedlings with the poorest quality. Consequently, T8 can be adopted by nursery producers as an alternative to peat moss in the production of quality tomato transplants. More research on other locally available organic substrates is encouraged to find out alternatives to expensive media like peat moss because it was observed that the use of sand + goat manure + carbonised rice husk 50 %: 10 %: 40 % revealed in production of quality seedlings with no significant difference from the ones grown in peat moss.

Development of an Autoinducible Plasmid for Recombinant Protein Production.

The production of recombinant proteins in E. coli involves such factors as host strains, expression vectors, culture media, and induction methods. The typical procedure to produce heterologous proteins consists of the following: (1) insertion of the target gene into a suitable vector to construct an overexpression plasmid, (2) transformation of a strain specialized for protein production with the constructed plasmid DNA, (3) growth of the host in a suitable medium and induction of the protein production at a right moment, and (4) further growth to get the maximum yield. There are hurdles involved in each of these steps, and researchers have developed many materials or methods, which often require special recipes or procedures. To eliminate the special requirements for recombinant protein production by using readily available materials. Also to save time and effort in the routine protein production work. We started with a vector capable of producing a target protein fused to the C-terminus of the maltose-binding protein (MBP). The mCherry (red fluorescent protein) gene was fused to MBP. It acted as a reporter in the initial screening procedure. The original lethal gene (barnase) was replaced with sacB. We chose 3 stationary phase promoters and made hybrids of them by mixing halves from each one. The T5 promoter was replaced with these stationary phase promoters or their hybrids. The best plasmid was selected by the color intensity of the cell pellet. MBP and GST genes were inserted in the place of sacB, and their production yields were compared with the original plasmid in the conventional way of expression. We constructed an expression plasmid with an autoinducible promoter working in a host that was not specially designed for protein production and in a TB medium that did not contain any secret ingredient, nor was it difficult to prepare unlike Studier's defined medium. This plasmid also contains a color indicator that turns red when protein production is successful. We tested our system with the maltose-binding protein (MBP) and the glutathione S-transferase (GST), and showed that both proteins were produced to a level comparable to what the commercial medium and/or the specialized strain yielded. We developed a plasmid equipped with an autoinducible promoter, a hybrid of the two promoters which were activated at the stationary phase. This plasmid does not need a special E. coli strain nor a sophisticated nor an expensive medium. It produces an intense red (or pink) color, which can be used as an indicator of a successful production of the target protein and as a predictive measure of the amount of the produced target protein. We speculate that this plasmid will have its greatest advantage when growing cells at low temperatures, which would inevitably take a long time.

Conditions for maintenance of hepatocyte differentiation and function in 3D cultures

SummarySpheroid cultures of primary human hepatocytes (PHH) are used in studies of hepatic drug metabolism and toxicity. The cultures are maintained under different conditions, with possible confounding results. We performed an in-depth analysis of the influence of various culture conditions to find the optimal conditions for the maintenance of an in vivo like phenotype. The formation, protein expression, and function of PHH spheroids were followed for three weeks in a high-throughput 384-well format. Medium composition affected spheroid histology, global proteome profile, drug metabolism and drug-induced toxicity. No epithelial-mesenchymal transition was observed. Media with fasting glucose and insulin levels gave spheroids with phenotypes closest to normal PHH. The most expensive medium resulted in PHH features most divergent from that of native PHH. Our results provide a protocol for culture of healthy PHH with maintained function - a prerequisite for studies of hepatocyte homeostasis and more reproducible hepatocyte research.

Use of Recycled Objects as English Teaching Media for Young Learners (A Theoretical Review)

This study is a library study about the use of recycled object as teaching media. The use of teaching media is one of the supporting components in teaching. Especially for young learners, the choice of media is an important thing to support them in learning English. Several media can be selected by teachers to be given to young learners. One of them is disposable media in the form of recycled objects that use objects around us. The teacher must be able to create the media to make the learning process more fun and informative. Through recycled objects as teaching media, young learners can learn how to use objects around them without having to use expensive media for learning. Therefore, this article was aimed at sharing the use of recycled objects as English teaching media for young learners. So that, young learners are expected to be motivated in the learning process.

Use of Recycled Objects as English Teaching Media for Young Learners

This study is a library study about the use of recycled object as teaching media. The use of teaching media is one of the supporting components in teaching. Especially for young learners, the choice of media is an important thing to support them in learning English. Several media can be selected by teachers to be given to young learners. One of them is disposable media in the form of recycled objects that use objects around us. The teacher must be able to create the media to make the learning process more fun and informative. Through recycled objects as teaching media, young learners can learn how to use objects around them without having to use expensive media for learning. Therefore, this article was aimed at sharing the use of recycled objects as English teaching media for young learners. So that, young learners are expected to be motivated in the learning process.

Review of different propagation media for potato mini tuber production under screen house

Scarcities of healthy and quality potato tuber seeds are the problem of the production of potatoes in the world. Especially, in developing countries it is a serious problem that cause decline in the production and productivity of the potatoes and hampers the profits of producers. To alleviate this problem, many countries produce the mini tubers in screen house from diseases-free planting materials in pots or seed bade made of pathogen-free media. Most reviewed papers indicated that a media used to grow potato in screen houses are made of a combination of different substrates for the suitability of the crop gown on it as it provides sufficient nutrients, aeration, support, and water. Developed countries use rock wool, vermiculite, peat, and other expensive media made by factories while the underdeveloped use cheap materials that are easily available in their surroundings like forest soil, sand, compost, and FYM (farm yard manure). There is also limited research concerning these materials in developing countries, especially, about the ratio of mixing and types to be mixed. The expensive materials used for pot media making are not found in Ethiopia though there are surplus raw materials. Therefore, this review was conducted to assess the information available about the different screen house growing media used worldwide and conceptualize for future utilization. It is concluded that researchers should work on the availability of healthy and quality tuber seed by increasing the numbers produced in screen house through agronomic and other techniques of production solving problems related to potting media.

The prospects of brewery waste application in biohydrogen production by photofermentation of Rhodobacter sphaeroides

Selection of the source for biohydrogen (H2) production is essential, since it affects bacterial metabolism. Pure organic substrates give fast H2 generation with high yields, but they increase the production cost. Using industrial wastes as a source provides inexpensive energy generation with simultaneous waste utilization. H2 production by photofermentation of Rhodobacter sphaeroides is monitored during cultivation on brewery waste. Maximum specific growth rate is observed for 5–10% waste containing media. H2 production by cells, grown on waste, is detected at 48–96 h of growth; it is comparable or higher than that of control medium with expensive carbon and nitrogen sources. N,N′-dicyclohexylcarbodiimide-sensitive ATPase activity of R. sphaeroides membrane vesicles from growth on waste containing media is 1.6–1.7-fold higher compared to control, correlating with enhanced H2 production. Growth medium containing optimal amount of wastes may be a successful alternative to expensive media for high H2 yield in R. sphaeroides during photofermentation.

Evaluation of soilless growing media for cost effective production of coloured capsicum under protected conditions

Capsicum or bell pepper (Capsicum annuum L.) isproduced world over and its area coverage combinedwith chilli is 1.5 million ha with output of 19.0 milliontons (Anonymous 2020). In India, the area coverage is46.0 thousand ha with a production of 326.0 thousandtons (Anonymous 2019). It is an important crop of openfields, but with advent and popularization of greenhousetechnology, it has occupied top place under protectedconditions. Bell pepper has potential to improve theeconomy of farmers grown as an offseason crop andhas good export value. Though, soil of uniform textureis the least expensive medium for plant growth, but soildoes not always occur in perfect package. When adverseconditions are found in soil and reclamation is impractical,the need of soilless culture is justified.

Developing an advertising strategy of new product

Modern advertisingof consumer goods is developing at a rapid pace, providing ample opportunity to support for launching thousands of new items into the market. Manufacturers make the signifcant investments in various channels of communication of goods for communication with consumers, so a properly designed advertising strategy and its implementation in business is an indisputable step to achieve success of product’s realization on market. However, there is no unifed approach to the strategic planning of effective advertising support for new product, it remains is open to both academics and practitioners, and needs further development. The paper deals with the general defnitions of scientific concepts: "strategy" and "advertising strategy". The main stages of creating an advertising strategy to achieve the necessary communication effect and to obtain a positive consumer’s response are formed. Given the high level of competition in the consumer market, an analysis of market factors influencing this process is one of the frst stages of developing an advertising strategy. The existing classifcation was analyzed and the modern approach to the distribution of these factors was determined. The second step is choosing the purpose and strategic goals for building an effective advertising strategy. Starting from goals and consumer interests, there are many types of advertising strategies in the advertising market. Was examined the classifcation of advertising strategies and proposed to expand them. Depending on the components of the promotion, it is suggested to divide them into product's and image's. According to this classifcation, was analyzed using of advertising strategies by modern enterprises in 2019. Was determined that a well-formed advertising strategy of the enterprise will allow to expand the target audience when launching a new product on the market. The next important step in developing an advertising strategy is the media planning and budgeting. Was investigated the level of investments into different channels of communication, based on the data of the Ukrainian Advertising Association. Was determined that television is the most effective and expensive media channel. At the same time, the best in the terms of growth of investment relative to previous years is digital channel. Particular should be attentioned the stage of advertising creative making and the choice of the communication platform, which is the largest in period of formation of advertising strategy. The manufacturer needs to investigate and evaluate the buyer's response to the promotional product at all stages of a likely purchase. Was determined that for the correct reading of the idea of advertising, the optimal number of major messages in it should be no more than fve. Has been researched that the effectiveness of the advertising appeal is determined by the observance of psychological neutrality in relation to the whole audience involved in one way or another in the advertising campaign. When the advertising product is ready, advertising can be launched into media space. Choosing effective media channels is tailored to the needs of your target audience. The next step is following an analysis of economic efciency and effectiveness of psychological impact of advertasing strategy. According to the results of this analysis, the stages of developing a new product advertising strategy are adjusted. Key words: advertising strategy, new product, advertising, media planning, budgeting of advertising, digital, media space, effectiveness of advertising.

Principles of in vitro nutrition for human mesenchymal stromal cells

Background & Aim In the cultivation of stem cells in vitro, components of animal origin and/or chemically undefined extracts like human platelet lysate are still used for the formulation of culture media because the quality of the most common basal media is unsuitable for cell culture in chemically defined environments. Experimental evidence shows that the better the qualitative and quantitative composition of the basal medium, the fewer additives of animal origin or chemically undefined components are needed to achieve successful cultivation of stem cells. Methods, Results & Conclusion The contribution deals with essential aspects concerning identity and quality of culture media components for pre-clinical and clinical research. It describes the development of physico-chemically defined micro-environments for cell cultures that modulate functions of the metabolism of human stem cells from adipose tissue (hASCs). The development process consists of two parts. The first phase involves the development of fully defined cellular microenvironments capable of satisfying the essential physiological needs of the cell. For this purpose, a detailed analysis of the physical (pH, osmotic pressure) and chemical requirements (energy sources, amino acids, vitamins, precursors of fatty and nucleic acids, inorganic salts, trace elements and chemical impurities) of the cells is carried out, which are then selected for the second phase. The second phase involves the elimination of complex, chemically undefined variables such as fetal calf serum or human platelet lysate, which are to be considered as critical components in cell culture media. The selection of a suitable basal medium and relative preparation technique allows the achievement of the goal. The results show that good knowledge of the variables that influence cellular growth processes has numerous advantages. The two-step strategy described above allows the identification of the essential physiological needs of the cells, thus favouring control and modulation of the main metabolic functions. This perspective becomes even more interesting as the omission of complex and expensive medium additives in clinical culture processes leads to a reduction of contamination risk and production costs.

Evaluation of the Medium Fermentative Parameters for the Production of Biosurfactant Using the Candida Gloebosa

The environmental pollution issue related to the widespread use of synthetic surfactants in detergents since 1960s has worried both the scientific community and regulatory agencies, in view of the foaming in rivers and lakes that makes the aquatic environment visually polluted. In this context, biological surfactants have stood out over synthetics due to their biodegradability and biological origin, since they are naturally produced by the microorganisms’ metabolism. However, the production usually requires expensive fermentative media and still demands more efficient methodologies to make the process economically advantageous. To the best of our knowledge, there are no studies in the literature reporting the use of Candida gloebosa, which was collected in Antartica, for producing of biological surfactants. Faced with this, the present study aimed to evaluate some fermentative medium parameters in order to obtain ideal conditions for biosurfactant production using Candida gloebosa. For this purpose, the fermentation time (24, 48, 72 and 96 h), the concentration of residual potato frying oil (40, 60 and 90 g.L-1), the concentration of hydrated magnesium sulfate (MgSO4.7H2O) (0.1, 0.15, 0.2 and 0.3 g.L-1), and cells concentration (1 ± 0.2, 2 ± 0.3, 3 ± 0.2 e 4 ± 0.3 g.L-1) were evaluated. According to the results, all the four parameters investigated revealed similar production yields at their best condition with a biosurfactant production of about 4 g/L when were employed 72 h of fermentation time, 0.2 g.L-1 of MgSO4, 60 g.L-1 of residual potato frying oil and a cell concentration of 3 g.L-1. Finally, the obtained results were comparable to those already reported in the literature for the yeast of the same genus known as Candida lipolytica, which is used for biosurfactant production. These findings can be used as basis for future studies involving the modeling through neural networks, for instance, in order to obtain an optimized condition or even for biosurfactant production in larger scales.