Alternative Culture Medium Research Articles

Rubber seed shell as low-cost medium to produce lactic acid using Lactobacillus plantarum LB2 and fabrication of a polylactic acid-chitosan composite for fish fillet packing

Rubber seed shell (Hevea brasiliensis) was used as a low-cost substrate to produce lactic acid via Lactobacillus plantarum LB2. The medium components were initially screened by two-level full factorial design. Three variables (pH, moisture, and polyoxyethylene sorbitan monooleate (PSM)) were used in the central composite design and response surface methodology. The amount of PSM was found to be a significant variable in lactic acid production. Lactic acid was purified and used for the chemical fabrication of a polylactic acid-chitosan composite film. Compared with the polylactic acid, the composite film improved the tensile strength, elongation strength, and tearing strength. The film prepared with 1% chitosan-polylactic acid exhibited the maximum antibacterial activity against Bacillus cereus (21 ± 1 mm) and the lowest activity against Escherichia coli (10 ± 1 mm). The polylactic acid-chitosan film prepared with 1% chitosan was used as a packing material to store the fish fillets and presented reduced mesophilic (4.3 ± 0.1 Log CFU/g) and psychrotropic (3.2 ± 0.2 Log CFU/g) bacterial populations compared with those of the control (4.9 ± 0.2 Log CFU/g and 3.7 Log CFU/g). Rubber seed shells can be used as an alternative culture medium for lactic acid production, to reduce the production cost of polylactic acid.

Upcycling food waste as a low-cost cultivation medium for Chlorella sp. microalgae.

Global food loss and waste have raised environmental concerns regarding the generation of greenhouse gases (e.g., carbon dioxide and methane gas), which directly contribute to climate change. To address these concerns, the present research aims to upcycle food waste into an alternative culture medium for the cultivation of microalgae. Various parameters including pretreatment of food waste (i.e., autoclave and non-autoclave), concentration of food waste culture medium (i.e., 10%, 30%, 50%, 70%, 90% and 100%), harvesting efficiency and biochemical compounds of Chlorella sp. microalgae were carried out. Based on the preliminary findings, the highest biomass concentration obtained from 10% food waste culture medium in the autoclave for Chlorella sp., including strains FSP-E, ESP-31 and CY-1, were 2.869 ± 0.022, 2.385 ± 0.018 and 0.985 ± 0.0026 g L-1, respectively. Since Chlorella vulgaris FSP-E exhibited the highest biomass concentration, this microalgal strain was selected to examine the subsequent parameters. Cultivation of C. vulgaris FSP-E in 100FW achieves a biomass concentration of 4.465 ± 0.008 g L-1 with biochemical compounds of 6.94 ± 1.396, 248.24 ± 0.976 and 406.23 ± 0.593 mg g-1 for lipids, carbohydrates and proteins, respectively. This study shows that using food waste as an alternative culture medium for C. vulgaris FSP-E can achieve substantial biomass productivity and biochemical content. This research work would contribute to the concept of net zero emission and transitioning toward a circular bioeconomy by upcycling food waste as an alternative culture medium for the cultivation of microalgae. © 2024 Society of Chemical Industry.

Use of waste frying oil and coconut pulp for the production, isolation, and characterization of a new lipase from Moesziomyces aphidis

Lipases comprise the third most commercialized group of enzymes worldwide and those of microbial origin are sought for their multiple advantages. Agro-industrial waste can be an alternative culture medium for producing lipases, reducing production costs and the improper disposal of waste frying oil (WFO). This study aimed to produce yeast lipases through submerged fermentation (SF) using domestic edible oil waste as inducer and alternative culture medium. The optimal culture conditions, most effective inducer, and purification method for a new lipase from Moesziomyces aphidis BRT57 were identified. Yeast was cultured in medium containing green coconut pulp and WFO waste for 72 h. The maximum production of lipases in SF occurred in a culture medium containing WFO and yeast extract at 48 and 72 h of incubation, with enzyme activities of 8.88 and 11.39 U mL−1, respectively. The lipase was isolated through ultrafiltration followed by size exclusion chromatography, achieving a 50.46 % recovery rate. To the best of our knowledge, this is the first study to report the production and purification of lipases from M. aphidis, demonstrating the value of frying oil as inducer and alternative medium for SF, contributing to the production of fatty acids for biodiesel from food waste.

Microalgae Biomass Production from Rice Husk as Alternative Media Cultivation and Extraction of Phycocyanin Using 3D-Printed Ohmic Heating Reactor.

Phycocyanin is a highly valued pigment present in Spirulina platensis biomass with applications in the food industry in terms of biorefinery concepts; specifically, its antioxidant and antimicrobial capacity are an advantage that could be incorporated into a food matrix. This study aims to use rice husk as an alternative culture medium for S. platensis biomass growth and phycocyanin extraction by ohmic heating processing using a 3D-printed reactor. S. platensis was cultivated in rice husk extract (RHE) from 0-100% (v/v). The highest content of microalgal biomass was 1.75 ± 0.01 g/L, with a specific growth rate of 0.125 ± 0.01 h-1. For the phycocyanin extraction under an ohmic heating process, a 3D-printed reactor was designed and built. To optimize phycocyanin extraction, a central composite rotatable design (CCDR) was evaluated, with three factors: time (min), temperature (°C), and pH. The highest phycocyanin content was 75.80 ± 0.98 mg/g in S. platensis biomass grown with rice husk extract. Ohmic heating is a promising method for rapid phycocyanin extraction, and rice husk as a culture medium is an alternative for the growth of S. platensis biomass in the integration of second- and third-generation biorefineries.

PEMANFAATAN KULIT Musa paradisiaca DAN Musa acuminata SEBAGAI MEDIA PERTUMBUHAN Rhizopus sp. DAN Saccharomyces cerevisiae

Banana peels contains simple sugars and complex sugars which can be utilized in metabolism of microorganisms. This means that banana peels can be used as an alternative culture medium for microorganisms. Rhizopus sp. and Saccharomyces cerevisiae is a type of microbe that often found in nature, and is one type of microbe that can be used in the food and non-food industries. In general, fungi need nitrogn, carbon, vitamins and growth factors. In this research, two types of fungi were grown on the Musa paradisiaca peels (pisang tanduk) and Musa acuminata peels (pisang kepok), as well as potato dextrose agar as a control medium. Growth was observed 24, 48 and 72 hours after inoculation. The data obtained is a qualitative data and analyzed descriptively. We found that the growth results on alternative medium using M. acuminata were quite good for Rhizopus sp. and S. cerevisiae. Meanwhile, medium using M. paradisiaca more suitable for the growth of Rhizopus sp. Keywords: Musa paradisiaca peels, Musa acuminata peels, Rhizopus sp., Saccharomyces cerivisiae

Development of an alternative low-cost culture medium for a new isolated high-production DHA strain using kitchen wastewater

Docosahexaenoic acid (DHA) is a high-value polyunsaturated fatty acid. The industrial development of microbial DHA was restricted due to high medium cost. Kitchen wastewater was always rich in nitrogen, phosphorous, carbohydrates, which can be used for microorganism growth. This study developed of a primitive low-cost culture medium for a new isolated high-production DHA strain using kitchen wastewater. The results showed that, a total of 66 strains were isolated from mangrove habitats. The highest DHA-producing strain N6 was identified as Aurantiochytrium sp. (GenBank accession number OL455742) with a DHA production of 6.56 g/L. Then the optimization of kitchen wastewater medium was designed by Response Surface Methodology, and 7.14 ∼ 7.23 g/L of DHA production was obtained. At the same time, the lipid content in Aurantiochytrium sp. N6 was as high as 75.68%, which contributed to the increase of DHA production in optimal kitchen wastewater medium. Finally, the substrate cost of kitchen wastewater medium was reduced by 43.95%. Meanwhile, the dissolved organic carbon (DOC), dissolved nitrogen (DN) and dissolved phosphorus (DP) in kitchen wastewater were utilized by Aurantiochytrium sp. N6 more than 90%. This work enriched the competitive candidate DHA-producing microbes, and provided a perceptive idea for both the medium substrate cost reducing and kitchen wastewater recycling.

Effects of marine sediment as agricultural substrate on soil microbial diversity: an amplicon sequencing study

BackgroundThe soil microbiota has a direct impact on plant development and other metabolic systems, such as the degradation of organic matter and the availability of microelements and metabolites. In the context of agricultural soils, microbial activity is crucial for maintaining soil health and productivity. Thus, the present study aimed to identify, characterize, and quantify the microbial communities of four types of substrates with varying proportions of marine port sediment used for cultivating lemons. By investigating microbial diversity and relative abundance, the work aimed to highlight the importance of soil microbial communities in agriculture when alternative culture media was used.ResultsThe composition and structure of the sampled microbial communities were assessed through the amplification and sequencing of the V3-V4 variable regions of the 16 S rRNA gene The results revealed a diverse microbial community composition in all substrate samples, with a total of 41 phyla, 113 classes, 266 orders, 405 families, 715 genera, and 1513 species identified. Among these, Proteobacteria, Bacteroidota, Planctomycetota, Patescibacteria, Chloroflexi, Actinobacteriota, Acidobacteriota, Verrucomicrobiota, and Gemmatimonadota accounted for over 90% of the bacterial reads, indicating their dominance in the substrates.ConclusionsThe impact of the substrate origin on the diversity and relative abundace of the microbiota was confirmed. The higher content of beneficial bacterial communities for plant development identified in peat could explain why is considered an ideal agricultural substrate. Development of “beneficial for plants” bacterial communities in alternative agricultural substrates, regardless of the edaphic characteristics, opens the possibility of studying the forced and specific inoculation of these culture media aiming to be agriculturally ideals.

Employing alternative culture media in kefiran exopolysaccharide production: Impact on microbial diversity, physicochemical properties, and bioactivities

Kefiran is a biomaterial with potential application in developing novel materials for food technology. In this study, sugarcane sugar (REF), raw sugar (RAS), brown sugar (BRS), soy molasses (SOM), and sugarcane molasses (SCM) were evaluated for the production of kefiran from kefir biomass rather than cow's milk (CMK), the usual medium. The produced kefiran was purified and characterized by colorimetry, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis, and morphology. It was also assayed for antioxidant and antimicrobial activity. SCM had the highest average daily rate of kefir biomass production (29.17 %/day). The composition of the culture medium affected the microbial diversity of kefir grains, and the Lactobacillus genus was the most abundant (39.8 %, 40.0 %, and 83.9 % to SCM, SOM, and CMK, respectively) in the samples that presented the highest biomass production and kefiran extraction yields. FTIR spectra showed that the bands of kefiran produced in REF and RAS were narrower than those of the other samples. Kefiran grew in an alternative culture medium also exhibited higher thermal stability (Tonset and TMax was higher than 250 and 280 °C, respectively). Those grown in SOM and SCM displayed antimicrobial and antioxidant activities similar to those of kefiran produced in CMK. The results indicate that agro-industrial by-products (SCM and SOM) are potential alternatives for kefiran production from kefir biomass.

Date Palm (Phoenix dactylifera L.) Flour as an Alternative Culture Media for the Growth of Escherichia coli and Bacillus cereus

The high cost of bacterial growth culture media can result in obstacles in the process of practicum or research in the field of microbiology. Date palm (Phoenix dactylifera L.) is the oldest fruit plant that grows in the Arabian Peninsula, North Africa and the Middle East. Dates are a source of high energy food with sugar content of 72% - 88%. This research was conducted to test the ability of date palm flour to grow Escherichia coli and Bacillus cereus bacteria as an alternative medium to replace NA media. In this study using total number of bacteria/ TPC (Total Plate Count) method to calculated the number of colonies of bacteria. The results of this study the number of colonies of Escherichia coli bacteria was more than the number of colonies of Bacillus cereus, that is 54 x 105CFU/g on concentration media 8 gr. When compared with NA media, date palm flour media can be used as an inexpensive alternative culture medium for bacteria.

Alternative culture medium design for biomass production of autochthonous meat starter Latilactobacillus sakei sp. sakei ACU-2

The autochthonous strain Latilactobacillus sakei sp. sakei ACU-2 was selected as a meat starter culture for dry sausage production. Transferring this strain from laboratory scale to industry requires an increase in biomass production, while lowering process costs. In this study, a combination of techniques was applied in order to optimize the culture medium composition to enhance biomass production of L. sakei ACU-2. One variable at a time experiments, Plackett–Burman design, and mixture design were performed to fulfill the strain nutritional requirements. Eventually, the optimized formulation contained 19.46 g/L yeast extract; 8.28 g/L whey protein concentrate; 2.26 g/L soy peptone; 30 g/L cerelose; 1 g/L Tween 80; 5 g/L sodium acetate; 0.2 g/L magnesium sulfate and 0.05 g/L manganese sulfate. When L. sakei ACU-2 was cultivated in a bioreactor using the alternative medium, an enhancement of 75.5% of biomass production was achieved, in comparison to its growth in the commercial de Man, Rogosa, and Sharpe medium. Furthermore, a reduction of 62–86% of the cost was also attained. These results support a promising large-scale application of the designed medium for high biomass yields of the starter culture at minor costs.

Exploration and Biorefinery Antimicrobial Agent through Solid State Fermentation from Indonesia’s Marine Actinomycetes

This study aimed to obtain novel bioactive compounds derived from actinomycetes associated with marine biota from the coast of Indonesia. Actinomycetes have been identified as a potential source of bioactive compounds through enzymatic fermentation. In order to obtain bioactive compounds from the results of the biorefinery process, cultivation was performed by solid state fermentation (SSF) on shrimp shell waste medium. The inhibitory activity against pathogenic microorganisms was measured based on the optical density of samples from Gorontalo and Buleleng, Bali, Indonesia. Six isolates had a clear zone as an indicator of the chitinase activity of chitinase enzymes. The SSF extract, obtained after 14 days of incubation, was assayed for its antimicrobial activity by the 96-well plate microtiter method. Among the six isolates, isolate 19B19A1 had antibacterial and antifungal activity against Staphylococcus aureus and Malassezia globosa, respectively. DNA analysis indicated that the 19B19A1 isolate was Streptomyces tritolerans 19B19A1 and that its extract contained an alkaloid component that played a role in antimicrobial activity. These results indicate that shrimp shells can be used as a nutrient-rich alternative culture medium for actinomycetes. This study is expected to become a source of information related to biorefinery, especially in the exploration of bioactive compounds produced by actinomycetes.

Cassava wastewater valorization for the production of biosurfactants: surfactin, rhamnolipids, and mannosileritritol lipids.

The global production of cassava was estimated at ca. 303 million tons. Due to this high production, the cassava processing industry (cassava flour and starch) generates approximately ca. 0.65kg of solid residue and ca. 25.3 l of wastewater per kg of fresh processed cassava root. The composition of the liquid effluent varies according to its origin; for example, the effluent from cassava flour production, when compared to the wastewater from the starch processing, presents a higher organic load (ca. 12 times) and total cyanide (ca. 29 times). It is worthy to highlight the toxicity of cassava residues regarding cyanide presence, which could generate disorders with acute or chronic symptoms in humans and animals. In this sense, the development of simple and low-cost eco-friendly methods for the proper treatment or reuse of cassava wastewater is a challenging, but promising path. Cassava wastewater is rich in macro-nutrients (proteins, starch, sugars) and micro-nutrients (iron, magnesium), enabling its use as a low-cost culture medium for biotechnological processes, such as the production of biosurfactants. These compounds are amphipathic molecules synthesized by living cells and can be widely used in industries as pharmaceutical agents, for microbial-enhanced oil recovery, among others. Amongst these biosurfactants, surfactin, rhamnolipids, and mannosileritritol lipids show remarkable properties such as antimicrobial, biodegradability, demulsifying and emulsifying capacity. However, the high production cost restricts the massive biosurfactant applications. Therefore, this study aims to present the state of the art and challenges in the production of biosurfactants using cassava wastewater as an alternative culture medium.

Sustainable Exopolysaccharide Production by Rhizobium viscosum CECT908 Using Corn Steep Liquor and Sugarcane Molasses as Sole Substrates.

Microbial exopolysaccharides (EPS) are promising alternatives to synthetic polymers in a variety of applications. Their high production costs, however, limit their use despite their outstanding properties. The use of low-cost substrates such as agro-industrial wastes in their production, can help to boost their market competitiveness. In this work, an alternative low-cost culture medium (CSLM) was developed for EPS production by Rhizobium viscosum CECT908, containing sugarcane molasses (60 g/L) and corn steep liquor (10 mL/L) as sole ingredients. This medium allowed the production of 6.1 ± 0.2 g EPS/L, twice the amount produced in the standard medium (Syn), whose main ingredients were glucose and yeast extract. This is the first report of EPS production by R. viscosum using agro-industrial residues as sole substrates. EPSCSLM and EPSSyn exhibited a similar carbohydrate composition, mainly 4-linked galactose, glucose and mannuronic acid. Although both EPS showed a good fit to the Herschel-Bulkley model, EPSCSLM displayed a higher yield stress and flow consistency index when compared with EPSSyn, due to its higher apparent viscosity. EPSCSLM demonstrated its potential use in Microbial Enhanced Oil Recovery by enabling the recovery of nearly 50% of the trapped oil in sand-pack column experiments using a heavy crude oil.

Probiotic characterization of indigenous lactic acid bacteria isolates from chickens to be used as biocontrol agents in poultry industry

AbstractLactic acid bacteria (LAB) are used as probiotics to improve animal health and production. This study aimed to characterize and assess three LAB, Ligilactobacillus salivarius 1234C, Ligilactobacillus agilis 1235C and Enterococcus durans 12311C, isolated from chicken, as potential probiotic candidates to improve the production parameters of commercial poultry. Resistance to gastrointestinal conditions, growth in alternative culture media, antagonistic activity against Salmonella and mycotoxigenic fungi were investigated. Additionally, the strains were added to poultry feed to evaluate their in vivo effect. The three LAB showed high survival rates after sequential gastric and intestinal conditions, demonstrated bactericidal activity against Salmonella and were able to grow in alternative culture media. Also, ligilactobacilli strains exerted fungicidal activity against mycotoxigenic fungi. In vivo assay showed that dietary supplementation of a multi‐microbe probiotic product with 107 CFU/ml significantly increased (p < .05) height: crypt depth ratio at 16 days compared to controls and promoted the highest average weight in chickens. Thus, three novel LAB strains with potential as probiotic properties have been characterized and could be considered probiotic candidates for animal production.Novelty impact statementIt is important to find novel probiotic candidates to improve and complement current treatment strategies in the poultry industry. Three indigenous lactic acid bacteria from poultry were found to possess suitable in vitro probiotic properties. Moreover, the inclusion of these strains as a multi‐microbe probiotic product in the diet of broiler chickens had no adverse effects on the general health status of broilers and showed a positive effect on the average daily weight at the final growth period.

Independent control of molecular weight, concentration, and stiffness of hyaluronic acid hydrogels

Hyaluronic acid (HA) hydrogels have been used for a multitude of applications, perhaps most notably for tissue engineering and regenerative medicine, owing to the versatility of the polymer and its tunable nature. Various groups have investigated the impact of hydrogel parameters (e.g. molecular weight, concentration, stiffness, etc) in vitro and in vivo to achieve desired material performance characteristics. A limitation in the literature to date has been that altering one hydrogel parameter (a ‘manipulated variable’) to achieve a given hydrogel characteristic (a ‘controlled variable’) changes two variables at a time (e.g. altering molecular weight and/or concentration to investigate cell response to stiffness). Therefore, if cell responses differ, it may be possible that more than one variable caused the changes in observed responses. In the current study, we leveraged thiol-ene click chemistry with a crosslinker to develop a method that minimizes material performance changes and permitted multiple material properties to be independently held constant to evaluate a single variable at a time. Independent control was accomplished by tuning the concentration of crosslinker to achieve an effectively constant stiffness for different HA hydrogel molecular weights and polymer concentrations. Specific formulations were thereby identified that enabled the molecular weight (76–1550 kDa), concentration (2%–10%), or stiffness (∼1–350 kPa) to be varied while the other two were held constant, a key technical achievement. The response of rat mesenchymal stem cells to varying molecular weight, concentration, and stiffness demonstrated consistent upregulation of osteocalcin gene expression. The methodology presented to achieve independent control of hydrogel parameters may potentially be adopted by others for alternative hydrogel polymers, cell types, or cell culture medium compositions to minimize confounding variables in experimental hydrogel designs.

Alternative cost-effective media to facilitate MODS culture for diagnostics of tuberculosis

Most culture-based methods for tuberculosis diagnosis remain low-cost options for low- and mid-income countries. The MODS culture is a rapid and low-cost assay to diagnose tuberculosis and determine drug susceptibility. However, its implementation is limited due to the low accessibility to supplies required for the enriched medium. In this study, we evaluate two alternative culture media: A powder-based mixed (PM) and a lyophilized media (LM). Catalase, PANTA, and gamma irradiation were evaluated as additions to PM and LM. The culture performance of the alternative media was compared with the standard MODS medium (MM) using Mycobacterium tuberculosis isolates and positive acid-fast smear sputum samples. Overall, no significant difference was observed in the bacterial growth between PM and LM with MM. However, PANTA and gamma irradiation combined reduced bacterial growth significantly in all media variants. A median positivity day of 6 ± 5 days was observed for sputum samples, regardless of the culture medium. The preliminary results show that the two variants culture media have a similar performance to the standard MODS medium. The powder-based media with PANTA (PM_P) showed a time-to-positivity and sensitivity similar to the standard MODS medium. It is the simplest to prepare and does not require any sterilization process.

Production of biosurfactants by Mucoralean fungi isolated from Caatinga bioma soil using industrial waste as renewable substrates

In this work it was investigated the potential of Mucorales fungi isolated from the Caatinga of Pernambuco state for production of biosurfactants using renewable substrates. The strains (Mucor circinelloides UCP 0005, M. circinelloides UCP 0006 and Rhizopus arrhizus UCP 1609) were cultivated in alternative culture media consisting of instant noodle waste (INW), corn steep liquor (CSL) and post-frying soybean oil (PFSO), according to conditions established by a 23 full-factorial design (FFD). The production of biosurfactants was evaluated by determining surface tension and emulsification index (EI24) and statistical analysis was performed using Pareto diagram. The presence of the main sources of carbon and nitrogen in production medium was confirmed by FTIR spectroscopy. According to the results, the three fungi evaluated were able of produce biosurfactant in media containing renewable sources. However, the strain that showed the greatest reduction in surface tension (72 to 27 mN/m) was M. circinelloides UCP 0006 in condition 3 of the FFD (1% INW and 4% CSL, in absence of PFSO). The infrared analysis of the INW showed the presence of carbohydrates, fatty acids and proteins, proving that this is a suitable substrate for the cultivation of fungi. The biosurfactants produced by M. circinelloides UCP 0005 and M. circinelloides UCP 0006 were able to form water-in-oil emulsions and the biosurfactant from R. arrhizus UCP 1609 formed oil-in-water emulsions. The present study demonstrated that the three Mucorales fungi tested were able to produce biosurfactants from renewable sources, with emphasis on M. circinelloides UCP 0006.

Effect of light/dark cycles on the growth of Haematococcus pluvialis in mixotrophic cultivation with alternative culture media

Effect of light/dark cycles on the growth of Haematococcus pluvialis in mixotrophic cultivation with alternative culture media

Pigment production by Scenedesmus dimorphus using different low‐cost and alternative culture media

AbstractBACKGROUNDThis study investigated the feasibility of producing pigments from Scenedesmus dimorphus using different low‐cost synthetic and alternative media. Thus the influence of nitrogen and phosphorus deficiency, different nitrogen sources and alternative culture media (wheat bran, garlic powder, wheat bran supplemented with garlic powder) on pigment and biomass production was evaluated.RESULTSAmong the three sources of nitrogen studied (ammonium sulfate, urea and sodium nitrate), urea was the cheapest efficient alternative source of nitrogen for pigment production, especially total chlorophylls (67.38 μg L−1 d−1), by this strain, without strongly affecting biomass yield. Phosphorus deficiency had no negative effect on biomass production, but improved the production of zeaxanthin and chlorophyll b by13.1% and 26.8%, respectively, compared to control. Compared to BG‐11 medium, the alternative garlic powder medium increased the biomass yield of S. dimorphus by 5.2 times, improved the productivity of xanthophylls and contributed to the accumulation of β‐carotene.Wheat bran medium was found to be efficient as a zero‐cost culture medium for the production of pigments, where S. dimorphus accumulated twice the total pigment concentration of the control, with high β‐carotene productivity (38.58 ± 11.94 μg L−1 d−1). The addition of garlic powder to wheat bran increased the biomass (3.14 g L−1) and pigment productivity (216.86 ± 2.06 μg L−1 d−1) by 28.5 and 1.4 times, respectively, but inhibited zeaxanthin biosynthesis. This alternative medium reduced biomass and pigment production costs by 99.80% and 96.21%, respectively.CONCLUSIONWheat bran supplemented with garlic powder showed good application potential for the industrial production of biomass and pigments from S. dimorphus in open cultivation systems where garlic powder might be used simultaneously for biomass and pigment accumulation, and for biological contamination control. © 2021 Society of Chemical Industry (SCI).

Optimisation of the timing of fertilisation assessment for oocytes cultured in standard incubation: lessons learnt from time-lapse imaging of 78 348 embryos.

Using time-lapse data, can the current consensus for the timing of fertilisation assessment of oocytes, cultured in standard incubation, be optimised? The optimum time to perform fertilisation assessment for oocytes cultured in standard incubation is 16.5 ± 0.5 h post-insemination (hpi), and the current consensus requires modification in order to minimise the chance of fertilisation being missed. Time-lapse incubation allows the embryologist to retrospectively review collated images of oocytes and embryos to capture important embryological observations that may otherwise be missed in standard incubation. According to expert consensus, the optimum time to perform the assessment of fertilisation is 17 ± 1 hpi. A retrospective, multicentre analysis utilised data obtained from 54 746 ICSI-derived embryos and 23 602 IVF-derived embryos cultured in time-lapse incubation between January 2011 and November 2019. Using time-lapse imaging (TLI), the precise time of pronuclei appearance and disappearance was recorded, where applicable, and the number of oocytes with two pronuclei observable during 10 30-min intervals from 15 hpi to 20 hpi was determined. Between 15 and 17.5 hpi, the average number of oocytes exhibiting normal fertilisation, elicited as two pronuclei, was 98.19% with the highest proportion of oocytes having visible pronuclei at 16-16.5 hpi (98.32%). At 18-18.5 hpi, the number of visible pronuclei reduced to 95.53% and continued to fall to 87.02% at 19.5-20 hpi. The authors' expectation is that these findings are transferable to other settings, however it is possible that, with alternative culture media and incubation environments, calibration of this timing may be required. As data cannot readily be recorded for pronuclear appearance for IVF-derived embryos, it is not possible to determine the optimum time to perform the fertilisation assessment for IVF-derived embryos. By fine-tuning the time at which fertilisation assessment takes place the accuracy of the assessment can be increased to maximise the number of fertilised oocytes identified, thereby increasing the number of usable embryos for the patient. Without TLI and following current consensus guidelines, over 11% (n = 3000) of oocytes would have been marked as unfertilised within this cohort. Further to this, depending on the time of a standard fertilisation assessment, up to 300 embryos which resulted in live births could have been categorised as unfertilised, as they presented no visible pronuclei at the conventional assessment time-point. A.C. is a minor shareholder in CARE Fertility Limited. Validated algorithmic time-lapse embryo selection is offered to patients at CARE Fertility at an additional charge as an adjuvant treatment option. N/A.