Sole Food Source Research Articles

Upcycling of food waste streams to valuable biopigments pyocyanin and 1-hydroxyphenazine

Phenazines, including pyocyanin (PYO) and 1-hydroxyphenazine (1-HP) are extracellular secondary metabolites and multifunctional pigments of Pseudomonas aeruginosa responsible for its blue-green color. These versatile molecules are electrochemically active, involved in significant biological activities giving fitness to the host, but also recognized as antimicrobial and anticancer agents. Their wider application is still limited partly due to the cost of carbon substrate for production, which can be solved by the utilization of carbon from food waste within the biorefinery concept. In this study, a variety of food waste streams (banana peel, potato peel, potato washing, stale bread, yoghurt, processed meat, boiled eggs and mixed canteen waste) was used as sole nutrient source in submerged cultures of P. aeruginosa BK25H. Stale bread was identified as the most suitable substrate to support phenazine biopigments production and bacterial growth. This was further increased in 5-liter fermenter when on average 5.2 mg L-1 of PYO and 4.4 mg L-1 of 1-HP were purified after 24 h batch cultivations from the fermentation medium consisting of homogenized stale bread in tap water. Purified biopigments showed moderate antimicrobial activity, and showed different toxicity profiles, with PYO not being toxic against Caenorhabditis elegans, a free-living soil nematode up to 300 µg mL-1 and 1-HP showing lethal effects at 75 µg mL-1. Therefore, stale bread waste stream with minimal pretreatment should be considered as suitable biorefinery feedstock, as it can support the production of valuable biopigments such as phenazines.

From Food (Bread) waste to Bioethnol Producation

A handful of studies and rough estimations confirm that roughly 1.3 billion tons of food get wasted. The staggering volume of food waste management has been shed light and constitutes a significant challenge because of -its environmental, social, and economic impacts. Recent estimates suggest that 8-10% of global greenhouse gas emissions are due to non-food conception, and the global economic costs of food waste have reached US$750 million per Annam. That is why Sustainable Development Goal 12.3 calls for the importance of food waste management. Wastes of bread represent an important fraction of retail food leftovers. If non-consumed food has been widely valorized in previous years, bread waste is nowadays increasingly of heightened attention. Bread waste can be a promising feedstock for producing bio-conversion value-added products. Recently, several technological methods have been reported for the possibility of transforming bread waste into eco-friendly materials such as ethanol, lactic acid, succinic acid, biohydrogen… etc. This study, based on recent research, sheds light on the possibility to convert food waste, especially bread leftovers into bioethanol by using waste bread as the sole source of nutrients for the growth of Aspergillus niger, which produces glucose, and Saccharomyces cerevisiae, which produces ethanol from glucose (i).

Isolation of a novel feather-degrading Ectobacillus sp. JY-23 strain and characterization of a new keratinase in the M4 metalloprotease family

Microbial keratinases have prominent potential in biotransformation of recalcitrant keratin substrates to value-added products which has made keratinases a research focus in the past decades. In this study, an efficient feather-degrading bacterium was isolated and identified as a novel species in Ectobacillus genus and designated as Ectobacillus sp. JY-23. The degradation characteristics analysis revealed that Ectobacillus sp. JY-23 could utilize chicken feathers (0.4% w/v) as the sole nutrient source and degraded 92.95% of feathers in 72 h. A significant increase in sulfite and free sulfydryl group content detected in the feather hydrolysate (culture supernatant) indicated efficient reduction of disulfide bonds, which inferred that the degradation mechanism of isolated strain was a synergetic action of sulfitolysis and proteolysis. Moreover, abundant amino acids were also detected, among which proline and glycine were the predominant free amino acids. Then, the keratinase of Ectobacillus sp. JY-23 was mined and Y1_15990 was identified as the keratinase encoding gene of Ectobacillus sp. JY-23 and designated as kerJY-23. Escherichia coli strain overexpressing kerJY-23 degraded chicken feathers in 48 h. Finally, bioinformatics prediction of KerJY-23 demonstrated that it belonged to the M4 metalloprotease family, which was a third keratinase member in this family. KerJY-23 showed low sequence identity to the other two keratinase members, indicating the novelty of KerJY-23. Overall, this study presents a novel feather-degrading bacterium and a new keratinase in the M4 metalloprotease family with remarkable potential in feather keratin valorization.

Excess glucose or fat differentially affects metabolism and appetite-related gene expression during zebrafish embryogenesis

Zebrafish embryos use their yolk sac reserve as the sole nutrient source during embryogenesis. The two main forms of energy fuel can be found in the form of glucose or fat. Zebrafish embryos were exposed to glucose or injected with free fatty acid/Triacylglycerol (FFA/TAG) into the yolk sac at 24 hpf. At 72 hpf, glucose exposed or FFA/TAG injected had differential effects on gene expression in embryos, with fat activating lipolysis and β-oxidation and glucose activating the insulin pathway. Bulk RNA-seq revealed that more gene expression was affected by glucose exposure compared to FFA/TAGs injection. Appetite-controlling genes were also differently affected by glucose exposure or FFA/TAG injections. Because the embryo did not yet feed itself at the time of our analysis, gene expression changes occurred in absence of actual hunger and revealed how the embryo manages its nutrient intake before active feeding.

Navigating practical applications of food waste valorisation based on the effects of food waste origins and storage conditions

Food wastes used as feedstock in biorefineries are of both research and market interest for solving related environmental issues and valorising to value-added products. However, the distinct conditions and characteristics governing the valorisation of different types of food waste remain to be addressed, such as different origins and storage conditions of food wastes. In this study, the characteristics of four types of food waste (student canteen waste, bakery waste, Chinese food waste, and Western food waste) after designed storage experiments (storage temperature − 4°C, 25 °C, and 35 °C; storage duration 1–3 days) were first investigated, followed by enzymatic hydrolysis to obtain food waste hydrolysates that can be applied to microalgal fermentation. The results showed that the characteristics of the food wastes and their corresponding hydrolysates differed based on their origins. Furthermore, cultivation of the microalgae Euglena gracilis demonstrated the feasibility of using food waste hydrolysates as the sole nutrient source, and both the origin and storage conditions of food wastes were found to affect microalgal growth and paramylon production. Possible inhibitors that could account for the different performances of food waste hydrolysates were identified by untargeted metabolite analysis. In summary, this study provides insights into the application of different types of food waste under complex conditions in biorefineries and the utilisation of their hydrolysates via in-depth metabolite analysis.

Comparative genomics reveal distinct potential of Tamlana sp. S12 for algal polysaccharide degradation

IntroductionMacroalgae contain various polysaccharides that serve as nutrient sources Introduction: Macroalgae contain various polysaccharides that serve as nutrient sources for marine bacteria. Carbohydrate-active enzymes (CAZymes) are the primary feature of marine bacteria that utilize these polysaccharides. In this study, we describe Tamlana sp. S12, a novel strain of marine flavobacteria that can degrade alginate and Laminaria japonica biomass, isolated from the intestines of the sea cucumber Apostichopus japonicas collected at Weihai coast.MethodsWe sequenced the entire genome of strain S12 and constructed a phylogenetic tree using the core genome sequences of related strains. We determined the enzymatic activity of strain S12 using the DNS method and measured its growth curve under different carbon sources using spectrophotometry.ResultsStrain S12 degraded dehydrated L. japonica fragments as the sole nutrient source within 48h. Strain S12 harbors a diverse array of CAZymes at multiple polysaccharide utilization loci (PUL). One PUL encoding lyases from PL6, 7, and 17 families may be used for the degradation of alginate. Additionally, strain S12 harbors PULs encoding carrageenan- and agar-targeting CAZymes. Comparative analysis with related flavobacteria from Algibacter, Maribacter, and Zobellia showed shared CAZymes among these strains, potentially derived from a common ancestor and stably maintained within strains. Genomic signatures, algal degradation ability, and CAZyme patterns suggest that strain S12 has the potential to degrade complex algal polysaccharides.ConclusionThese results expand our knowledge of CAZymes and enrich our understanding of how marine Flavobacteriaceae adapt to marine algal polysaccharide environments. The availability of the genome of Tamlana sp. S12 will be beneficial for further analyses of marine Flavobacteriaceae.

Functional and evolutionary implications of protein and metal content of leafhopper brochosomes

Brochosomes derived from the specialized glandular segments of the Malpighian tubules (MTs) form superhydrophobic coatings for insects of Membracoidea, and have multiple hypothetical functions. However, the constituents, biosynthesis and evolutionary origin of brochosomes remain poorly understood. We investigated general chemical and physical characteristics of the integumental brochosomes (IBs) of the leafhopper Psammotettix striatus, determined the constituents of IBs, identified the unigenes involved in brochosomal protein synthesis, and investigated the potential associations among brochosomal protein synthesis, amino acid composition of food source, and the possible roles of endosymbionts in brochosome production. The results show that IBs are mainly composed of glycine- and tyrosine-rich proteins and some metal elements, which contain both essential and non-essential amino acids (EAAs and NEAAs) for insects, including EAAs deficient in the sole food source. All 12 unigenes involved in synthesizing the 12 brochosomal proteins (BPs) with high confidence are exclusively highly expressed in the glandular segment of MTs, confirming that brochosomes are synthesized by this segment. The synthesis of BPs is one of the key synapomorphies of Membracoidea but may be lost secondarily in a few lineages. The synthesis of BPs might be related to the symbiosis of leafhoppers/treehoppers with endosymbionts that provide these insects with EAAs, including those are deficient in the sole diet (i.e., plant sap) and could only be made available by the symbionts. We hypothesize that the functional modification of MTs have combined with the application of BPs enabling Membracoidea to colonize and adapt to novel ecological niches, and evolve to the dramatic diversification of this hemipteran group (in particular the family Cicadellidae). This study highlights the importance of evolutionary plasticity and multiple functions of MTs in driving the adaptations and evolution of sap-sucking insects of Hemiptera.

Characterization of the Keratinolytic Activity of Three Streptomyces Strains and Impact of Their Co-Cultivation on This Activity.

In this study, we describe the characterization of three efficient chicken feather-degrading Streptomyces bacteria isolated from honeybee samples and assess the impact of their co-cultivation on this activity and antistaphylococcal activity. Streptomyces griseoaurantiacus AD2 was the strain showing the highest keratinolytic activity (4000 U × mL-1), followed by Streptomyces albidoflavus AN1 and Streptomyces drozdowiczii AD1, which both generated approximately 3000 U × mL-1. Moreover, a consortium constituted of these three strains was able to use chicken feathers as its sole nutrient source and growth in such conditions led to a significant increase in antibiotic production. S. griseoaurantiacus AD2 was the only strain that exhibited weak antimicrobial activity against Staphylococcus aureus. UPLC analyses revealed that a significant number of peaks detected in the extracts of co-cultures of the three strains were missing in the extracts of individual cultures. In addition, the production of specialized metabolites, such as undecylprodigiosin and manumycin A, was clearly enhanced in co-culture conditions, in agreement with the results of the antimicrobial bioassays against S. aureus. Our results revealed the benefits of co-cultivation of these bacterial species in terms of metabolic wealth and antibiotic production. Our work could thus contribute to the development of novel microbial-based strategies to valorize keratin waste.

Nicotinic Acid Catabolism Modulates Bacterial Mycophagy in Burkholderia gladioli Strain NGJ1.

Burkholderia gladioli strain NGJ1 exhibits mycophagous activity on a broad range of fungi, including Rhizoctonia solani, a devastating plant pathogen. Here, we demonstrate that the nicotinic acid (NA) catabolic pathway in NGJ1 is required for mycophagy. NGJ1 is auxotrophic to NA and it potentially senses R. solani as a NA source. Mutation in the nicC and nicX genes involved in NA catabolism renders defects in mycophagy and the mutant bacteria are unable to utilize R. solani extract as the sole nutrient source. As supplementation of NA, but not FA (fumaric acid, the end product of NA catabolism) restores the mycophagous ability of ΔnicC/ΔnicX mutants, we anticipate that NA is not required as a carbon source for the bacterium during mycophagy. Notably, nicR, a MarR-type of transcriptional regulator that functions as a negative regulator of the NA catabolic pathway is upregulated in ΔnicC/ΔnicX mutant and upon NA supplementation the nicR expression is reduced to the basal level in both the mutants. The ΔnicR mutant produces excessive biofilm and is completely defective in swimming motility. On the other hand, ΔnicC/ΔnicX mutants are compromised in swimming motility as well as biofilm formation, potentially due to the upregulation of nicR. Our data suggest that a defect in NA catabolism alters the NA pool in the bacterium and upregulates nicR which in turn suppresses bacterial motility as well as biofilm formation, leading to mycophagy defects. IMPORTANCE Mycophagy is an important trait through which certain bacteria forage over fungal mycelia and utilize fungal biomass as a nutrient source to thrive in hostile environments. The present study emphasizes that nicotinic acid (NA) is important for bacterial motility and biofilm formation during mycophagy by Burkholderia gladioli strain NGJ1. Defects in NA catabolism potentially alter the cellular NA pool, upregulate the expression of nicR, a negative regulator of biofilm, and therefore suppress bacterial motility as well as biofilm formation, leading to mycophagy defects.

Feasibility study of value-added production from onion peel agricultural wastes for circular economy

BackgroundAs a highly populated and resource-limited Taiwan, material recycling and reuse are of great importance to satisfy net-zero waste accumulation while simultaneously developing value-added production for circular economy. Herein, quercetin-rich onion peel wastes were chosen as a model to consider the technical feasibility of material recycling through fermentation. Pretreatment of onion peels extracts (OPEs) through frozen-preservation methods and serial acclimation via lactose-degrading bacteria was implemented for comparative optimization. MethodsOptimal extraction conditions (e.g., solvent, temperature of extraction, and frozen-preservation time) were first determined. Batch cultures of Lactobacillus sp. and Yogurt mixed consortia were implemented to maximize quercetin product formation using OPEs as sole nutrient sources via fermentation. Comparative assessment was performed by assessing total phenolic content, total quercetin content, and quercetin concentration. Microbial fuel cells were used to investigate time courses of electrochemical characteristics of residual OPEs during fermentation. Significant findingsComparative assessment revealed that OPEs could be optimized under extraction conditions of 50% ethanol as solvent, 75 °C extraction temperature, and frozen-preservation temperature of -20 °C. Yogurt mixed consortia yielded higher quercetin production that Lactobacillus sp. at 9 days fermentation. Phase-plane trajectories also revealed that using extracts frozen for 84 days at -20 °C through 9-day fermentation could achieve maximal quercetin production (ca. 1.5–1.75-fold compared to no fermentation). MFC results suggested that OPE fermentation was electrochemically favorable to enhance quercetin generation. Approximately two or three cycles of bacterial acclimation is sufficient to obtain maximal quercetin productivity and stable power-stimulating characteristics (ca. 1.35–1.5 fold power density amplification). To the best of our knowledge, this study was the first work to quantitatively decipher the most appropriate operation strategy for quercetin production from agricultural wastes (OPEs).

Macronutrient composition of term and preterm human milk of different socio economic groups

Assessment of the nutritional composition of Human Breast Milk (HBM) is important to understand its sufficiency as the sole nutrient source in infants. The present study is aimed to analyze the proximate composition along with total amino acid and fatty acid profile in term and preterm HBM of different socio economic status.This cross sectional study included, 120 lactating mothers with term or preterm gestation from maternity hospitals located in Hyderabad, Telangana. Nutritional proximate, total amino and fatty acid profiles were estimated in pooled human milk collected from each participant within the first week of postpartum.The macronutrient composition in term was similar to that of preterm breast milk. The essential amino acid Leucine was significantly high in preterm (8.91 ± 0.18) when compared to term (8.61 ± 0.23). ω-5 fatty acid Myristoleic acid was significantly high in preterm (0.14 ± 0.02) when compared to term (0.11 ± 0.02), whereas ω-6 fatty acids like Docosadienoic Acid and Eicosadienoic acid were found to be significantly high in term when compared to preterm. Further, it was also found that the mono unsaturated and ω-9 fatty acids were significantly high in lower socio economic group, whereas, poly unsaturated and ω -3 and 6 fatty acids were significantly high in upper socio economic group.The present study concludes that, nutritional composition like essential amino and fatty acids of human milk vary significantly between different gestational age as well as in socio economic groups.

Pre-, pro-, syn-, and Postbiotics in Infant Formulas: What Are the Immune Benefits for Infants?

The first objective of infant formulas is to ensure the healthy growth of neonates and infants, as the sole complete food source during the first months of life when a child cannot be breastfed. Beyond this nutritional aspect, infant nutrition companies also try to mimic breast milk in its unique immuno-modulating properties. Numerous studies have demonstrated that the intestinal microbiota under the influence of diet shapes the maturation of the immune system and influences the risk of atopic diseases in infants. A new challenge for dairy industries is, therefore, to develop infant formulas inducing the maturation of immunity and the microbiota that can be observed in breastfed delivered vaginally, representing reference infants. Streptococcus thermophilus, Lactobacillus reuteri DSM 17938, Bifidobacterium breve (BC50), Bifidobacterium lactis Bb12, Lactobacillus fermentum (CECT5716), and Lactobacillus rhamnosus GG (LGG) are some of the probiotics added to infant formula, according to a literature review of the past 10 years. The most frequently used prebiotics in published clinical trials are fructo-oligosaccharides (FOSs), galacto-oligosaccharides (GOSs), and human milk oligosaccharides (HMOs). This review sums up the expected benefits and effects for infants of pre-, pro-, syn-, and postbiotics added to infant formula regarding the microbiota, immunity, and allergies.

Multi-Seed Zea Pellets (MSZP) for increasing agroecosystem biodiversity

AbstractIntensive agricultural crop production is typically associated with low biodiversity. Low biodiversity is associated with a deficit of ecosystem services, which may limit crop yield (e.g., low pollination of insect-pollinated crops) at the individual field level or exacerbate the landscape-level impacts of intensive agriculture. To increase biodiversity and enhance ecosystem services with minimal loss of crop production area, farmers can plant desirable non-crop species near crop fields. Adoption of this practice is limited by inefficiencies in existing establishment methods. We have developed a novel seed-molding method allowing non-crop species to be planted with a conventional corn (Zea mays L.) planter, reducing labor and capital costs associated with native species establishment. Common milkweed (Asclepias syriaca L.) was selected as a model native species, because Asclepias plants are the sole food source for monarch butterfly (Danaus plexippus L.) larvae. Stratified A. syriaca seeds were added to a mixture of binder (maltodextrin) and filler (diatomaceous earth and wood flour) materials in a 3D-printed mold with the dimensions of a corn seed. The resulting Multi-Seed Zea Pellets (MSZP), shaped like corn seeds, were tested against non-pelleted A. syriaca seeds in several indoor and outdoor pot experiments. Molding into MSZP did not affect percent emergence or time to emergence from a 2-cm planting depth. Intraspecific competition among seedlings that emerged from an MSZP did not differ from competition among seedlings that emerged from a cluster of non-pelleted seeds. These findings demonstrate the potential of MSZP technology as a precise and efficient method for increasing agroecosystem biodiversity.

Evolving tolerance of Yarrowia lipolytica to hydrothermal liquefaction aqueous phase waste.

Hydrothermal liquefaction (HTL) is an emerging method for thermochemical conversion of wet organic waste and biomass into renewable biocrude. HTL also produces an aqueous phase (HTL-AP) side stream containing 2-4% light organic compounds that require treatment. Although anaerobic digestion (AD) of HTL-AP has shown promise, lengthy time periods were required for AD microbial communities to adapt to metabolic inhibitors in HTL-AP. An alternative for HTL-AP valorization was recently demonstrated using two engineered strains of Yarrowia lipolytica, E26 and Diploid TAL, for the overproduction of lipids and the polyketide triacetic acid lactone (TAL) respectively. These strains tolerated up to 10% HTL-AP (v/v) in defined media and up to 25% (v/v) HTL-AP in rich media. In this work, adaptive laboratory evolution (ALE) of these strains increased the bulk population tolerance for HTL-AP to up to 30% (v/v) in defined media and up to 35% (v/v) for individual isolates in rich media. The predominate organic acids within HTL-AP (acetic, butyric, and propionic) were rapidly consumed by the evolved Y. lipolytica strains. A TAL-producing isolate (strain 144-3) achieved a nearly 3-fold increase in TAL titer over the parent strain while simultaneously reducing the chemical oxygen demand (COD) of HTL-AP containing media. Fermentation with HTL-AP as the sole nutrient source demonstrated direct conversion of waste into TAL at 10% theoretical yield. Potential genetic mutations of evolved TAL production strains that could be imparting tolerance were explored. This work advances the potential of Y. lipolytica to biologically treat and simultaneously extract value from HTL wastewater. KEY POINTS: • Adaptive evolution of two Y. lipolytica strains enhanced their tolerance to waste. • Y. lipolytica reduces chemical oxygen demand in media containing waste. • Y. lipolytica can produce triacetic acid lactone directly from wastewater.

Continuous operation of fungal wheel reactor based on solid-state fermentation for the removal of pharmaceutical and personal care products

Wood-rotting fungi and their enzymatic systems represent promising biocatalysts for the removal of pharmaceuticals and personal care products (PPCPs) from wastewater. We designed a fungal wheel reactor (FWR) based on solid-state fermentation (SSF) of Trametes versicolor and a lignocellulosic substrate, which was used as an immobilization carrier for fungal biomass and the sole initial nutrient source for producing fungal oxidative enzymes. Three pharmaceutical and personal care products, acetaminophen, bisphenol A and carbamazepine, were spiked into the synthetic wastewater and the treatment was carried out under non-sterile conditions. Acetaminophen was completely removed from the FWR until laccase was observed. The acetaminophen removal efficiency was retrieved by replacing the fungal wheel with fresh SSF products. Bisphenol A and carbamazepine were removed via enzymatic activity and adsorption. When the fungal wheel was replaced, acetaminophen began to be completely removed, even after laccase depletion. The microbial community analysis indicated that the continuous removal of acetaminophen was mainly due to the high proportion of T. versicolor. The relative abundance of the co-occurring microbial community might be responsible for the divergence in acetaminophen removal between two of fungal wheel-replaced reactors. Overall, FWRs are promising tools for the removal of PPCPs by highly reactive enzymatic mechanisms as well as adsorption on the carrier surface. By replacing SSF and settled microbial communities, FWRs may continuously contribute to bioremediation over a long-term period.

A study on microbiota isolated from olive mill wastewater disposal ponds, with emphasis on filamentous fungi and their biodegradative potential in North Sinai Governorate, Egypt

The microbial composition of olive mill wastewater (OMWW) from six disposal ponds at three localities in North Sinai Governorate, Egypt has been studied. Such OMWW samples contained a variable (but high) number of bacteria, yeasts, and mold. Eighty-one isolates related to 9 bacterial species were recovered, and seven common bacterial species were isolated from Bir al Abd, Al-Arish, and Rafah sites sources namely Enterococcus faecalis, Escherichia coli, Bacillus cereus, B. subtilis, Micrococcus luteus, Pseudomonas aeruginosa, and Klebsiella pneumonia. In addition to these species, Vibrio cholerae and Shigella species were isolated from the Bir al Abd site. One hundred and twenty isolates related to 13 fungal species were recovered. Seven members of different fungal genera (Aspergillus, Penicillium, Fusarium, Paecilomyces, Alternaria, Chaetomium, and Rhizopus) were recorded. Four genera were widely distributed, and they were able to grow efficiently in undiluted OMWW as a sole source of nutrients. Strains of Aspergillus, Penicillium, Fusarium, and Paecilomyces showed a marked capacity for OMWW detoxification. The physicochemical studies further revealed the presence of relatively low levels of sodium, potassium, calcium, magnesium, and iron. Nitrate concentration was relatively high, 70.13 mg/L. The biological oxygen demand (BOD) and the chemical oxygen demand (COD) recorded high values that ranged between 2210-2270 mg/L and 22760-22800 mg/L, respectively. High BOD and COD values are important indicators of high organic and inorganic components of OMWW and possible negative environmental consequences. The presence of fungal and bacterial species implied possible degradation of the effluent.

The Negative Role of Formula Milk Advertisements in Media and its Consequences

Breast milk is secreted by the mammary gland of lactating mothers and is the cheapest sole nutrient source for feeding breastfed infants. Its protein, fat and carbohydrate contents are adequate from the quantitative and qualitative aspects for the growth and development of breastfed infants during the first six months of life. Additionally, it is a rich source of specific antibodies, hormones and immunoglobulins, which protect breastfed infants from many infectious diseases and possess positive health effects. The last decades witnessed the industrial production of breast milk substitutes, which are inferior in their quality compared to breast milk and more expensive. In 1981, an International Code was adopted by the World Health Assembly (WHA) to reduce inappropriate marketing and protect breastfeeding. Marketing of breast-milk alternatives such as many infant formulas are promoted to the consumers via a wide range of media coverage including newspapers, online communications and business websites. Such advertisement affects negatively cultural expectations by portraying supplement consumption as widespread, and cutting-edge. The expansion in the marketing and consumption of such products may be associated with deterioration in the nutritional and health status of infants and young children belonging to low-income households. In a research study published in 2003, ten million babies die before reaching their fifth birthday of life worldwide. Breastfeeding proved an especially successful strategy, with the potential to save 1.3 million lives. Formula use is associated with a higher likelihood of premature deaths and hospitalization

Okara Waste as a Substrate for the Microalgae Phaeodactylum tricornutum Enhances the Production of Algal Biomass, Fucoxanthin, and Polyunsaturated Fatty Acids

Despite the rich nutritional content of okara, the majority remains underutilized and discarded as food waste. In this study, solid-state fermentation of okara with food-grade fungi was performed to extract and solubilize any remnant nutrients locked within the lignocellulosic matrix to produce a nutrient-rich okara fermentate. Fermented okara media (FOM) was used as the sole nutrient source for growing marine diatom, Phaeodactylum tricornutum. Results have shown a two-fold increase in biomass production when grown on FOM (0.52 g L−1) as compared with conventional Guillard’s F/2 media (0.25 g L−1). Furthermore, cellular fucoxanthin content was enhanced significantly by two-fold to reach a final concentration of 15.3 mg g−1 compared to 7.3 mg g−1. Additionally, a significantly higher amount of polyunsaturated fatty acid (PUFA) was produced, particularly eicosapentaenoic acid (EPA) which yield has increased by nearly three-fold. Metabolomics analysis of intracellular contents in fermented okara culture revealed a significantly enhanced accumulation of nitrogenous metabolites, alongside the decrease in sugar metabolites as compared to F/2 culture, thus indicating metabolic flux towards pathways involved in cellular growth. This study demonstrated an innovative and low-cost strategy of using fermented okara as a nutritious substrate for achieving a sustainable media replacement for high density algal growth with a simultaneous enhancement of production in highly valued nutraceuticals, including fucoxanthin and EPA.

Evaluation of Rye Bran Enzymatic Hydrolysate Effect on Gene Expression and Bacteriocinogenic Activity of Lactic Acid Bacteria

Lactic acid bacteria (LAB) bacteriocins can be considered as a bio-preservatives and an alternative to antibiotics, but the high manufacturing costs limit their commercial application. The screening of LAB strains for bacteriocinogenic activity was carried out and the effect of rye bran enzymatic hydrolysate (RBEH) on gene expression and bacteriocin production was evaluated. qPCR and RT-PCR was applied for bacteriocin gene detection and their expression quantification. The agar diffusion technique with the test strains of Bacillus spp., Staphylococcus spp. and Salmonella enterica was performed for antimicrobial activity assessment of LAB cultivated in MRS broth and RBEH (processed with proteases and cellulases). The genes of different bacteriocins were revealed for thirteen out of eighteen LAB strains, while the antimicrobial activity was detected only for four of them. The strains of Lactobacillus paracasei VKPM B-11657 and L. salivarius VKPM B-2214 with unnamed class IIb bacteriocin gene demonstrated the widest spectrum of activity. The growth patterns and bacteriocin gene expression differed between both strains and media. The activity of cell-free supernatants after cultivation in RBEH was slightly lower. However, the test strain of S. epidermidis was inhibited by L. paracasei cultivated in RBEH but not in MRS. Thus, rye bran can be applied as a sole source of nutrients for LAB fermentation and bacteriocin production.

Establishing Minimal Conditions Sufficient for the Development of Titan-like Cells in Cryptococcus neoformans/gattii Species Complex.

Opportunistic pathogens of the anamorphic genus Cryptococcus are unique considering their virulence factors that in the context of pathogenesis allowed them to achieve evolutionary success. Morphological transformation into giant (Titan) cells is one of the factors contributing to cryptococcosis. Recently established in vitro protocols demonstrate that 5 or 10% fetal bovine serum (FBS) combined with 5% CO2, 37 °C, and sufficiently low cell density, triggers cellular enlargement (Serum protocols). However, the FBS components that promote this morphological transition remain incompletely characterized. In search of minimal conditions necessary for stimulating the formation of Titan cells, we performed a study where we eliminated serum from the protocol (Serum-free protocol) and instead systematically adjusted the amount of glucose, source of nitrogen (ammonium sulfate), and the pH. We found that exposing cells to PBS with adjusted pH to 7.3, and supplemented with 0.05% glucose, 0.025% ammonium sulfate, 0.004% K2HPO4, 0.0035% MgSO4, in the presence of 5% CO2 at 37 °C triggers Titan-like cell formation to the same degree as the previously established protocol that utilized 10% FBS as the sole nutrient source. Titan-like cells obtained according to this Serum-free protocol were characterized by cell body size over ten microns, a single enlarged vacuole, thick cell wall, extensive polysaccharide capsule, and changes in the level of cell ploidy, all currently known hallmarks of Titan cells found in vivo. Strikingly, we found that in both, Serum and Serum-free protocols, an optimal pH for Titan-like cell development is ~7.3 whereas relatively acidic pH (5.5) prevents this morphological transition and promotes robust proliferation, while alkaline pH (~8.0) has a profound growth inhibitory effect. Our study demonstrates a critical role of pH response to the formation of Titan cells and indicates that conditions that allow restricted proliferation in the presence of 5% CO2 are sufficient for this morphological transition to form enlarged cells in Cryptococcus neoformans and Cryptococcus gattii species complex.