Alternative Nutrient Sources Research Articles

Nutritional balance and production of sugarcane irrigated with treated wastewater through subsurface drip

Low sugarcane productivity in Brazil is due to insufficient rainfall and would benefit from irrigation. Thus, the application of treated wastewater, such as treated domestic sewage (TDS), becomes an alternative water and nutrient source for sugarcane cultivation. The objective of this research was to evaluate the productivity, soil fertility, fertilizer savings and nutritional balance during 2 years of sugarcane crops using TDS applied through subsurface drip irrigation. The experiment was conducted in the field under a randomized block design with five treatments, with two dripline depths and two water qualities (domestic sewage and surface reservoir) and finally non-irrigated plots. Productivity, nutritional balance, and soil fertility were measured during two harvest cycles. The irrigated treatments presented greater productivity in both ratoons (28.5% and 42.8%) and, consequently, higher nutrient extraction compared to the input, which provided a reduction of average soil fertility during the cycles evaluated. The dripline depths and the water qualities applied influenced concentrations of sodium in the soil profile, with highest levels in TDS treatments. Treatments with TDS also showed, in both cycles, significant savings of up to 100% on the application of nitrogen and phosphorus. Therefore, TDS applied by subsurface drip can be used as an irrigation alternative in sugarcane cultivation.

Impact of Hydrolysis Methods on the Utilization of Agricultural Residues as Nutrient Source for D-lactic Acid Production by Sporolactobacillus inulinus

d-lactic acid is a building block for heat resistant polylactic acid, a biobased polymer with a high potential. Nevertheless, an economically efficient industrial process for d-lactic acid production still needs to be implemented. Yeast extract is an expensive nutrient source, which is used to fulfill the complex nutritional requirements in lactic acid fermentations. The substitution of yeast extract by cheap alternative nutrient sources is a challenge in many fermentation processes. In this study, chemical and enzymatic hydrolysis techniques for protein rich agricultural residues and their effectiveness are compared, as well as their impact on the d-lactic acid production of Sporolactobacillus inulinus. An efficient substitution of yeast extract could be achieved by a variety of agricultural residues, hydrolysed with 3M H2SO4, demonstrating the much higher versatility and effectiveness of this method compared to enzymatic methods. In a fed-batch experiment with chemically hydrolyzed rapeseed meal and minimal supplementation, a lactic acid titer of 221 g L−1 and an overall productivity of 1.55 g (L h)−1 (96% yield) were obtained.

Carotenoid Production by Rhodotorula mucilaginosa in Batch and Fed-Batch Fermentation Using Agroindustrial Byproducts.

SUMMARYCarotenoids are natural pigments that can be produced through biotechnological processes. However, the costs are relatively high and can be minimized by using lower-cost substrates as alternative nutrient sources. The fed-batch fermentation is one of the techniques used to obtain a high biomass concentration and/or maximum production. Thus, the aim of this work is to produce carotenoids in batch and fed-batch fermentation with the yeast Rhodotorula mucilaginosa CCT 7688 using agroindustrial byproducts in the culture medium. Carotenoid production was increased using experimental designs, which modified the concentration of the agroindustrial medium. In batch production the highest concentrations of total carotenoids (1248.5 μg/L) and biomass (7.9 g/L) were obtained in the medium containing 70 g/L sugar cane molasses and 3.4 g/L corn steep liquor at 25 °C and 180 rpm in 168 h, demonstrating an increase of 17% when compared to the standard yeast malt medium (1200 μg/L). In the fed-batch production, different feeding strategies were tested with 30 g/L sugar cane molasses and 6.5 g/L corn steep liquor, reaching a total carotenoid production of 3726 μg/L and biomass concentration of 16 g/L. Therefore, the strategy of the fed-batch process resulted in an increase in the carotenoid production of approx. 400% compared to that in the batch process (740.3 μg/L). Thus, the R. mucilaginosa strain has the potential to produce carotenoids in agroindustrial medium.

Edible insects: Cross-recognition of IgE from crustacean- and house dust mite allergic patients, and reduction of allergenicity by food processing

BackgroundInsects have become increasingly interesting as alternative nutrient sources for feeding humans and animals, most reasonably in processed form. Initially, some safety aspects — among them allergenicity — need to be addressed. ObjectiveTo reveal the cross-reactivity of shrimp-, mite- and flies-allergic patients to different edible insects, and further to assess the efficacy of food processing in reducing the recognition of insect proteins by patients' IgE and in skin prick testing of shrimp-allergic patients. MethodsIgE from patients allergic to crustaceans, house dust mite or flies was evaluated for cross-recognition of proteins in house cricket Acheta domesticus (AD), desert locust Schistocerca gregaria (SG) and Yellow mealworm Tenebrio molitor (TM). Changes in IgE-binding and SPT-reactivity to processed insect extracts were determined for migratory locust (Locusta migratoria, LM), after different extraction methods, enzymatic hydrolysis, and thermal processing were applied. ResultsIgE from patients with crustacean-allergy shows cross-recognition of AD, SG and stable flies; house dust mite allergics' IgE binds to AD and SG; and the flies-allergic patient recognized cricket, desert locust and migratory locust. Cross-reactivity and allergenicity in SPT to LM can be deleted by conventional processing steps, such as hydrolysis with different enzymes or heat treatment, during the preparation of protein concentrates. ConclusionThe results show that crustacean-, HDM- and stable flies-allergic patients cross-recognize desert locust and house cricket proteins, and crustacean-allergic patients also flies proteins. Furthermore, this study shows that appropriate food processing methods can reduce the risk of cross-reactivity and allergenicity of edible insects.

Plant Growth, Antioxidative Enzymes and Lipid Peroxidation in Sunflower Seedlings Supplemented With Eichhornia crassipes Organic Fertilizer Under Drought Stress Conditions

In the semiarid region of the Brazilian Northeast, there is still the occurrence of soils with low concentrations of organic mass and nutrients. Eichhornia crassipes (water hyacinth) is recognized as one of the top ten endemic herbs in the world. However, its accumulation capacity means it can be an alternative source of nutrients. The objective of this study was to analyse the effects of macrophyte organic residue (ROM) on plant growth, antioxidative enzyme activity and membrane lipid peroxidation in leaves and roots of sunflower seedlings submitted to drought stress conditions. The experiment was conducted under greenhouse conditions at the Instituto Federal de Educação, Ciência e Tecnologia do Ceará, Maracanaú Campus, Brazil. Samples of E. crassipes were collected in the Parangaba Lagoon, Fortaleza, Ceará, Brazil. The treatments were: 1) 100% (by volume) sand; 2) sand + fertilizer (following the recommendation of 80 kg of N/ha), and 3) sand + 100% of the recommended nitrogen in macrophytes (RN). In general, the use of ROM caused better seedling growth in relation to the other treatments in all conditions studied. Increases in antioxidative enzyme activity and reductions in the deleterious effects of drought stress on plant growth were observed.

Complexo hidrossolúvel na formação de mudas do porta-enxerto limoeiro 'Cravo'

A formação de mudas frutíferas é uma fase importante da cadeia produtiva da fruticultura e na citricultura não é diferente, sobretudo na produção de mudas de qualidade. O uso de fontes alternativas de nutrientes minerais ofereceria novas opções de produto para fertilização aplicadas à agricultura moderna. Este trabalho teve como objetivo avaliar o crescimento e desenvolvimento de mudas de limoeiro 'Cravo' submetidas à aplicação de complexo hidrossolúvel em diferentes concentrações como fonte alternativa de nutrientes minerais. O experimento foi conduzido entre os meses de novembro de 2012 a abril de 2013, cujas mudas foram formadas em tubetes durante 150 dias. O complexo hidrossolúvel (CH) foi aplicado em cobertura mediante irrigação mensal com soluções nas concentrações de 0, 1, 2, 4 e 8 g L-1 sobre as mudas com ou sem adubação química convencional. As características avaliadas foram altura, diâmetro do colo, número de folhas, comprimento de raiz, massas fresca e seca da parte aérea e do sistema radicular, comprimento total de raízes e volume radicular. O CH influenciou na altura e diâmetro das mudas de limoeiro 'Cravo', cujas estimativas concentrações entre 4 e 8 g L-1 tenderam a promover melhores resultados. A adubação de cobertura com o CH associado à adubação química convencional promoveu melhor formação radicular em comprimento e volume, exceto quando se aplicou de 8 g L-1 do CH.

Tumour microenvironment and metabolic plasticity in cancer and cancer stem cells: Perspectives on metabolic and immune regulatory signatures in chemoresistant ovarian cancer stem cells.

Cancer stem cells (CSCs) are a sub-population of tumour cells, which are responsible to drive tumour growth, metastasis and therapy resistance. It has recently been proposed that enhanced glucose metabolism and immune evasion by tumour cells are linked, and are modulated by the changing tumour microenvironment (TME) that creates a competition for nutrient consumption between tumour and different sub-types of cells attracted to the TME. To facilitate efficient nutrient distribution, oncogene-induced inflammatory milieu in the tumours facilitate adaptive metabolic changes in the surrounding non-malignant cells to secrete metabolites that are used as alternative nutrient sources by the tumours to sustain its increasing energy needs for growth and anabolic functions. This scenario also affects CSCs residing at the primary or metastatic niches. This review summarises recent advances in our understanding of the metabolic phenotypes of cancer cells and CSCs and how these processes are affected by the TME. We also discuss how the evolving TME modulates tumour cells and CSCs in cancer progression. Using previously described proteomic and genomic platforms, ovarian cancer cell lines and a mouse xenograft model we highlight the existence of metabolic and immune regulatory signatures in chemoresistant ovarian CSCs, and discuss how these processes may affect recurrence in ovarian tumours. We propose that progress in cancer control and eradication may depend not only on the elimination of highly chemoresistant CSCs, but also in designing novel strategies which would intervene with the tumour-promoting TME factors.

Use of Organic Wastes and Industrial By-Products to Produce Filamentous Fungi with Potential as Aqua-Feed Ingredients

Organic-rich waste and industrial by-product streams, generated in enormous amounts on a daily basis, contain substantial amounts of nutrients that are worthy of recovery. Biological conversion of organic-waste streams using filamentous fungi is a promising approach to convert nutrients into value-added bioproducts, such as fungal biomass. High-protein fungal biomass contains different kinds and levels of amino acids, fatty acids, immunostimulants, antioxidants, pigments, etc., which make it a potential choice for application in animal feed supplementation. Considering the challenges long faced by the aquaculture industry in fishmeal production due to the increasing prices and environmental concerns, the aquaculture industry is forced to provide alternative protein-rich sources to replace conventional fishmeal. In this review, the possibilities of utilization of filamentous fungi biomass cultivated on organic-rich waste streams, as an alternative nutrient source in fish feed, were thoroughly reviewed.

N2O and CO2 emissions, nitrogen use efficiency under biogas slurry irrigation: A field study of two consecutive wheat-maize rotation cycles in the North China Plain

Reuse of biogas slurry (BGS) could reduce fertilizer application rate because this material is an alternative source of nutrients and irrigation that could replace some of applied fertilizer. However, the environmental impacts of BGS irrigation, such as greenhouse gas emissions (GHG) are poorly understood. We investigated the global warming potential (GWP) and greenhouse gas intensity (GHGI) of BGS irrigation by quantifying the nitrous oxide (N2O) and carbon dioxide (CO2) emissions under different BGS irrigation rates in a two-year wheat-maize rotation field in the North China Plain. We found BGS irrigation did not change the patterns and fluxes of CO2 and N2O emission during the entire wheat-maize cropping cycle. In addition, there were no significant difference between BGS treatments (BSL, BSM, and BSH) and conventional fertilizer treatment (CF) in GWP. Further, no significant difference occurred in GHGI between BSM (33% BGS and 67% groundwater were mixed and irrigated during the wintering period and joining stage of wheat and after maize sowing, 315 kg·N·hm−1), BSH (50% BGS and 50% groundwater were mixed and irrigated during the wintering period and joining stage of wheat and after maize sowing, 477 kg·N·hm−1) and CF (conventional NPK fertilizer, 420 kg·N·ha−1), despite a higher value BSL (33% BGS and 67% groundwater were mixed and irrigated during the wintering period of wheat and after maize sowing, 210 kg·N·hm−1).The BSL and BSM treatments significantly increased the nitrogen use efficiency (NUE) compared to the CF treatment (11.3% for BSL and 15.3% for BSM). Despite the lower NUE in the BSH treatment relative to CF, it was not statistically significant. Therefore, BGS reuse can increase NUE and does not cause environmental impacts. According to the results of GHGI and NUE, it can be concluded that BSM should be recommended as an improved recycling management practice for the wheat-maize rotation systems.

English

Potato (Solanum tuberosum L.) is an important food and cash crop in Kenya. However, its production has declined over the years due to extensive nutrient mining without adequate replacement. A study was conducted to evaluate the response of potato grown under three soil types (Planosol, Andosol and Acrisol) using three fecal matter fertilizers (FMFs). This included vermicompost, normal compost and dried sludge. In addition, common fertilizer (urea and cow manure) was also used. Two greenhouse trials were laid out in a randomized complete block design with four replicates per treatment. Data collected on soil nutrient status, plant growth and yield variables were subjected to analysis of variance using Statistical Analysis Software v.9.1 and treatment means separated using Tukey’s test. Results showed that fecal matter fertilizers (FMF) , vermicompost and dried sludge, were equally effective in increasing (39.2-46.5%) the potato growth compared to untreated control. Fecal matter fertilizers also contributed to high yields, where vermicompost produced (12.3 t ha-1) 3 times more than untreated control (4.2 t ha-1) but the difference was not significant at P≤0.05 from urea, normal compost and sludge. The interaction between fertilizers and soil types was not significant at P≤0.05. Fecal matter fertilizers are thus ecologically viable alternative source of mineral nutrients for sustainable potato production. Key words: Acrisol, andosol, planosol, Solanum tuberosum, sludge, vermicompost.

Apparent metabolisable energy and amino acid digestibility of microalgae Spirulina platensis as an ingredient in broiler chicken diets

ABSTRACT1. This work investigates the apparent metabolisable energy (AME), its nitrogen-corrected form (AMEn) and amino acid (AA) digestibility coefficients of the microalgae Spirulina platensis as an ingredient in broiler chicken diets.2. One group of birds was fed with a basal control diet (BD), and another was fed with a test diet composed of the BD with the addition of the microalgae at a proportion of 200 g/kg. AME and AMEn were assessed by total excreta collection and indigestibility analysis using acid-insoluble ash (AIA) as a marker.3. The microalgae comprised 888.0 g/kg dry matter (DM), 18.42 MJ/kg gross energy, 514.7 g/kg crude protein, 9.9 g/kg ether extract, 10.6 g/kg crude fibre, 94.4 g/kg ash, 3.1 g/kg Ca and 11.0 g/kg P.4. The values obtained for AME (13.48 MJ/kg DM) and AMEn (11.72 MJ/kg DM) were higher (p < 0.01) than those obtained using the AIA method (9.39–8.29 MJ/kg DM). The microalgae ileal digestibility coefficients were 0.80 ± 0.04 and 0.78 ± 0.04 for essential and non-essential AA, respectively.5. Overall, the metabolisable energy content and digestibility of AA for S. platensis indicated that the microalgae are potentially an alternative nutrient source for broilers. The AIA method underestimated AME and AMEn in comparison to the total excreta collection method.

Development of marine multi-algae cultures for biodiesel production

The concept of community ecology has become a central issue for sustainable biofuel production. However the development of appropriate multi-algae cultures for the industry remains challenging. Natural marine algae blooms collected from coastal areas of Cyprus were induced to form multi-algae cultures, and five (5) of those were developed and tested. Algae growth characteristics, biomass, and lipid productivity were assessed, and the dominant microalga was isolated in all cultures. Growth characteristics, lipid productivity, and FAME composition varied considerably among the different multi-algae cultures as well as their corresponding dominant species. Our results suggest that competitiveness and species complementarity could be crucial factors for biomass and lipid productivity. In material collected from the marina in Larnaca of Cyprus, the induced BL1_LCA bloom was the most promising culture, dominated by Nannochloropsis sp. and accompanied by cyanobacteria assemblages, exhibiting the highest biomass and lipid productivity compared to the other developed blooms. Biomass and lipid productivity of an axenic monoculture of Nannochloropsis sp. were 2.1 and 2.2 times lower compared to those measured in BL1_LCA. The growth parameters of BL1_LCA and its corresponding dominant species were further tested under culture media of different seawater and wastewater ratios. An increase of wastewater ratio in the culture media resulted in a significant reduction of lipid, FAME concentration as well as biomass productivity both in BL1_LCA and its dominant isolate. Overall, our findings suggest that the complex interactions within microalgae community might be crucial for biodiesel production; moreover, the general assumption that wastewater can be applied as an alternative nutrient source should be used cautiously since species-specific responses seem to take place.

Abstract 5471: EWS-FLI1 reprograms the metabolism of Ewing sarcoma cells via positive regulation of glutamine import and serine-glycine biosynthesis

Abstract Ewing sarcoma (EWS) is a soft tissue and bone tumor found primarily in adolescents and young adults. In most cases of EWS, the chimeric transcription factor, EWS-FLI1 is the primary oncogenic driver. The expression profile of EWS cells reflects EWS-FLI1 binding and activation or repression of transcription. Recent studies have shown EWS-FLI1 deregulates proteins that function in tryptophan metabolism (Mutz et al., 2016, FEBS Lett. 590, 2063) or serine-glycine biosynthesis (Tanner et al., 2017, Mol. Cancer Res., 11, 1517). In our study, we extend these findings by establishing that EWS-FLI1 transcriptionally regulates the expression of enzymes required for serine-glycine biosynthesis and the mitochondrial one-carbon cycle, and the uptake of the alternative nutrient source glutamine, directly. To identify metabolic pathways regulated by EWS-FLI1, we interrogated the expression profiles of EWS-FLI1-silenced TC32 EWS cells. We observed that silencing of EWS-FLI1 results in the decreased expression of genes required for serine-glycine biosynthesis specifically, PHGDH, PSAT1, PSPH, and SHMT2. Using ChIP analysis, we demonstrated that EWS-FLI1 binds specific regulatory regions within these four serine-glycine biosynthesis genes. Also, ectopic expression in 293T cells results in increased expression of PHGDH, PSAT1, PSPH, and SHMT2. Consistent with the ability of EWS cells to synthesize serine and glycine de novo, EWS cells grown in medium depleted of these amino acids exhibit no change in viability. However, EWS cells were sensitive to the depletion of glutamine. Analysis of the expression profiles of EWS-FLI1-silenced TC32 EWS cells showed EWS-FLI1 positively regulates expression of the glutamine transporter, SLC1A5 and that EWS cells require glutamine for glycine synthesis. Next, we examined metabolic processes downstream of serine-glycine biosynthesis and showed that enzymes associated with the mitochondrial one-carbon cycle, MTHFD2 and MTHD1L, are transcriptional targets of EWS-FLI1, but not their cytosolic counterpart MTHFD1. Our data suggests EWS-FLI1 favors activation of enzymes associated with the mitochondrial one-carbon cycle, which provides the reducing equivalents GSH and NADPH. Depletion of EWS-FLI1 or the inhibition of PHGDH reduced the GSH/GSSG and NADPH/NADP ratios in EWS cells resulting in increased production of reactive oxygen species, inducing DNA damage and apoptosis. Importantly, analysis of EWS primary tumor transcriptome data confirmed that the aforementioned metabolism genes we identified as regulated by EWS-FLI1 exhibit increased expression compared with normal tissues. In summary, our study demonstrates that EWS-FLI1 reprograms the metabolism of EWS cells and that serine-glycine metabolism and glutamine uptake are potential vulnerabilities in this tumor type. Citation Format: Nirmalya Sen, Allison M. Cross, Philip L. Lorenzi, Javed Khan, Berkley E. Gryder, Suntae Kim, Natasha J. Caplen. EWS-FLI1 reprograms the metabolism of Ewing sarcoma cells via positive regulation of glutamine import and serine-glycine biosynthesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5471.

EWS-FLI1 reprograms the metabolism of Ewing sarcoma cells via positive regulation of glutamine import and serine-glycine biosynthesis.

Ewing sarcoma (EWS) is a soft tissue and bone tumor that occurs primarily in adolescents and young adults. In most cases of EWS, the chimeric transcription factor, EWS‐FLI1 is the primary oncogenic driver. The epigenome of EWS cells reflects EWS‐FLI1 binding and activation or repression of transcription. Here, we demonstrate that EWS‐FLI1 positively regulates the expression of proteins required for serine‐glycine biosynthesis and uptake of the alternative nutrient source glutamine. Specifically, we show that EWS‐FLI1 activates expression of PHGDH, PSAT1, PSPH, and SHMT2. Using cell‐based studies, we also establish that EWS cells are dependent on glutamine for cell survival and that EWS‐FLI1 positively regulates expression of the glutamine transporter, SLC1A5 and two enzymes involved in the one‐carbon cycle, MTHFD2 and MTHFD1L. Inhibition of serine‐glycine biosynthesis in EWS cells impacts their redox state leading to an accumulation of reactive oxygen species, DNA damage, and apoptosis. Importantly, analysis of EWS primary tumor transcriptome data confirmed that the aforementioned genes we identified as regulated by EWS‐FLI1 exhibit increased expression compared with normal tissues. Furthermore, retrospective analysis of an independent data set generated a significant stratification of the overall survival of EWS patients into low‐ and high‐risk groups based on the expression of PHGDH, PSAT1, PSPH, SHMT2, SLC1A5, MTHFD2, and MTHFD1L. In summary, our study demonstrates that EWS‐FLI1 reprograms the metabolism of EWS cells and that serine‐glycine metabolism or glutamine uptake are potential targetable vulnerabilities in this tumor type.

Technological Use of Flour Obtained from the Byproducts of Passion Fruit Albedo and the Residue of the Extraction of the Star Fruit Juice in the Formulation of Cereal Bars

The fruits industrialization process for the production of new food products generates a significant number of agroindustrial residues. The use of these residues in the formulation of new products such as cereal bars adds nutritional value to foods and helps in the reduction of environmental impacts. The objective of this work was to produce flours from the star fruit residue and the passion fruit albedo, to attain the physicochemical characterization and to elaborate three cereal bars formulations with variation in the contents of the flour produced. The results indicate that the star fruit and the passion fruit’s albedo can be considered as an alternative source of nutrients, ranging from energy supplementation to its insertion in derived products due to its technological characteristics. The developed cereal bars were widely accepted, and most evaluators reported that they would buy such products. DOI: http://dx.doi.org/10.17807/orbital.v10i3.1102

Protein quality of four indigenous edible insect species in Nigeria

Food security is a serious concern particularly for developing countries. To overcome hunger and malnutrition there is a need for increased research towards finding alternative and cheaper sources of nutrients. Insects have been reported to be rich in protein and could be alternative sources of protein. This work was therefore designed to determine the protein quality of moth caterpillar, termite, cricket and grasshopper and the effects of diets supplemented with these insects on some biochemical and haematological indices of rats. The amino acid compositions of the insects were determined using standard analytical methods. Five iso-nitrogenous and isocaloric diets were formulated on a 10% protein basis with the insects and casein. A Nitrogen free diet was also formulated as control. Thirty six (36) young weanling albino rats (21–28 days old) were divided into 6 groups and fed with the diets ad libitum for 28 days. Their weekly weight gain and daily feed intake were recorded, urine and faeces were collected for nitrogen determination using Kjedahl method and the data obtained used to calculate the various protein quality indices. After the feeding trial periods, the rats were sacrificed, blood samples collected and organs excised for various analyses. Cricket was found to have the highest amino acid score (0.91), protein efficiency ratio (1.78), net protein ratio (3.04) biological value (93.02%) and protein digestibility corrected for amino acid score (0.73) as compared to other insect proteins analysed. The organ body weight ratios of the liver, spleen, lung and heart of rats placed on the insect supplemented diets were not significantly different (p>0.05) from those fed with casein and basal diets. Serum total protein concentrations in rats fed with cricket diet were not significantly different (p>0.05) from those fed casein diet while serum LDL cholesterol concentration was lowest in rats fed cricket diet. The finding in this work that the selected insects are nutritious and safe for consumption may alleviate the fear of entomophagy thereby reducing the overdependence on conventional animal proteins.

In Vitro Iron Bioavailability of Brazilian Food-Based by-Products.

Background: Iron deficiency is a public health problem in many low- and middle-income countries. Introduction of agro-industrial food by-products, as additional source of nutrients, could help alleviate this micronutrient deficiency, provide alternative sources of nutrients and calories in developed countries, and be a partial solution for disposal of agro-industry by-products. Methods: The aim of this study was to determine iron bioavailability of 5 by-products from Brazilian agro-industry (peels from cucumber, pumpkin, and jackfruit, cupuaçu seed peel, and rice bran), using the in vitro digestion/ Caco-2 cell model; with Caco-2 cell ferritin formation as a surrogate marker of iron bioavailability. Total and dialyzable Fe, macronutrients, the concentrations of iron-uptake inhibitors (phytic acid, tannins, fiber) and their correlation with iron bioavailability were also evaluated. Results: The iron content of all by-products was high, but the concentration of iron and predicted bioavailability were not related. Rice bran and cupuaçu seed peel had the highest amount of phytic acid and tannins, and lowest iron bioavailability. Cucumber peels alone, and with added extrinsic Fe, and pumpkin peels with extrinsic added iron, had the highest iron bioavailability. Conclusion: The results suggest that cucumber and pumpkin peel could be valuable alternative sources of bioavailable Fe to reduce iron deficiency in at-risk populations.

Regulation of Hydrolytic Enzyme Activity in Aquatic Microbial Communities Hosted by Carnivorous Pitcher Plants.

Carnivorous pitcher plants Sarracenia purpurea host diverse eukaryotic and bacterial communities which aid in insect prey digestion, but little is known about the functional processes mediated by the microbial communities. This study aimed to connect pitcher community diversity with functional nutrient transformation processes, identifying bacterial taxa, and measuring regulation of hydrolytic enzyme activity in response to prey and alternative nutrient sources. Genetic analysis identified diverse bacterial taxa known to produce hydrolytic enzyme activities. Chitinase, protease, and phosphatase activities were measured using fluorometric assays. Enzyme activity in field pitchers was positively correlated with bacterial abundance, and activity was suppressed by antibiotics suggesting predominantly bacterial sources of chitinase and protease activity. Fungi, algae, and rotifers observed could also contribute enzyme activity, but fresh insect prey released minimal chitinase activity. Activity of chitinase and proteases was upregulated in response to insect additions, and phosphatase activity was suppressed by phosphate additions. Particulate organic P in prey was broken down, appearing as increasing dissolved organic and inorganic P pools within 14days. Chitinase and protease were not significantly suppressed by availability of dissolved organic substrates, though organic C and N stimulated bacterial growth, resulting in elevated enzyme activity. This comprehensive field and experimental study show that pitcher plant microbial communities dynamically regulate hydrolytic enzyme activity, to digest prey nutrients to simpler forms, mediating biogeochemical nutrient transformations and release of nutrients for microbial and host plant uptake.

Environmental load assessment for an integrated design of microalgae system of palm oil mill in Indonesia

The environmental load of continuous bioenergy production from palm oil (Elaeis guineensis) included with a proposed 10 ha of microalgae production system were assessed to be implemented in Indonesia. Material and energy balances, greenhouse gas (GHG) emission, nutrient requirement and also water scarcity during bioenergy production cycle were evaluated. The integrated system was developed for 60 tons h−1 of fresh fruit bunch (FFB) processing capacity of a conventional mill. Aggregate of energy-profit ratio from the proposed system was 5.20, which indicates a positive balance. The total water footprint for each palm oil and microalgae cultivation was 3.18 and 2.85 m3 kg−1 of biodiesel production, respectively. Microalgae mix-culture has the potential to treat organic compounds from palm oil mill effluent (POME) and combined with flue gases from biomass and biogas power plant as the alternative nutrient sources contributed to net-reduction of GHG emission for 158.8 tons ha−1 of microalgae culture, annually. The integrated system produced 26,471 tons of biodiesel that included 223 tons from microalgae and contribute to 39.90% of total GHG emission reduction from diesel fuel substitute. Additional co-product of 520.33 tons year−1 of animal feed from defatted biomass also possible to be produced and have potential for environmental benefits.

Laboratory evolution reveals regulatory and metabolic trade-offs of glycerol utilization in Saccharomyces cerevisiae

Most microbial species, including model eukaryote Saccharomyces cerevisiae, possess genetic capability to utilize many alternative nutrient sources. Yet, it remains an open question whether these manifest into assimilatory phenotypes. Despite possessing all necessary pathways, S. cerevisiae grows poorly or not at all when glycerol is the sole carbon source. Here we discover, through multiple evolved lineages, genetic determinants underlying glycerol catabolism and the associated fitness trade-offs. Most evolved lineages adapted through mutations in the HOG pathway, but showed hampered osmotolerance. In the other lineages, we find that only three mutations cause the improved phenotype. One of these contributes counter-intuitively by decoupling the TCA cycle from oxidative phosphorylation, and thereby hampers ethanol utilization. Transcriptomics, proteomics and metabolomics analysis of the re-engineered strains affirmed the causality of the three mutations at molecular level. Introduction of these mutations resulted in improved glycerol utilization also in industrial strains. Our findings not only have a direct relevance for improving glycerol-based bioprocesses, but also illustrate how a metabolic pathway can remain unexploited due to fitness trade-offs in other, ecologically important, traits.