Preparation of a probiotic quinoa beverage by enzymatic hydrolysis of its starches and subsequent lactic acid fermentation / Elaboración de una bebida probiótica de quinua por hidrólisis enzimática de sus almidones y posterior fermentación ácido láctica

Background: The concern about consuming healthy foods has increased in recent years. Not only are they expected to comply with essential feeding functions, but they also provide health benefits. Probiotics are one of the main functional components expected to be present in functional foods and beverages. They provide many health benefits and stand out due to their metabolic capacities and adaptability to different habitats. In addition, Quinoa seeds contain valuable quantities of quality protein and nutritional values of carbohydrates, proteins, fats, fibers, and mineral substances for which they are considered an ideal dietary alternative. Objectives: This research aimed to elaborate on a probiotic quinoa beverage, which combines the effect of enzymatic hydrolysis of the starches obtained from its seeds with lactic acid fermentation using probiotic cultures, seeking to enhance its nutritional properties and converting it into a functional beverage. Methods: For this, fermentations were carried out in three different concentrations of probiotic cultures (inoculum): 10%, 5%, 1%, and three other different fermentation times: 8, 10, and 12 hours. pH, Total titrable acidity expressed as lactic acid (%), reducing sugars, and soluble solids were measured. After that, the beverage was formulated with honey, carob, preservatives, and mango flavoring. Results: Statistical analysis indicated optimal conditions were achieved with 10% probiotic cultures and 10 hours of fermentation. The microbiological analysis confirmed the presence of probiotic microorganisms at a concentration of 108 CFU/mL. Proximal analysis indicated that the composition contained 84.6 Kcal, 19.3 g of carbohydrates, and 1.4 g of protein per 100 g of beverage. Conclusions: The probiotic quinoa beverage was produced and can be considered in the group of plant-based foods, as well as a functional beverage, since the probiotic cultures it contains contribute to maintaining the intestinal microbiota and prevent the onset of chronic diseases.

Antecedentes: La preocupación por el consumo alimentos saludables ha aumentado en los últimos años. No solo se espera que cumplan con las funciones esenciales de alimentación, sino que también brinden beneficios para la salud. Los probióticos son uno de los principales componentes funcionales que se espera que estén presentes en los alimentos y bebidas funcionales. Aportan múltiples beneficios para la salud y destacan por sus capacidades metabólicas y adaptabilidad a diferentes hábitats. Además, las semillas de quinua contienen valiosas cantidades de proteína de notable calidad, valores nutricionales de carbohidratos, proteínas, grasas, fibras y sustancias minerales por lo que se consideran una alternativa dietética ideal. Objetivos: Esta investigación tuvo como objetivo elaborar una bebida probiótica de quinua, que combina el efecto de la hidrólisis enzimática de los almidones obtenidos de sus semillas con la fermentación láctica utilizando cultivos probióticos, buscando potenciar sus propiedades nutricionales y convertirla en una bebida funcional. Métodos: Para ello se realizaron fermentaciones en tres concentraciones diferentes de cultivos probióticos (inóculo): 10%, 5%, 1%, y tres distintos tiempos de fermentación: 8, 10 y 12 horas. Se midió pH, Acidez titulable total expresada como ácido láctico (%), azúcares reductores y sólidos solubles. Posteriormente, se formuló la bebida con miel, algarrobina, conservantes y saborizante de mango. Resultados: El análisis estadístico indicó que se lograron condiciones óptimas con 10% de cultivos probióticos y 10 horas de fermentación. El análisis microbiológico confirmó la presencia de microorganismos probióticos a una concentración de 108 UFC/mL. El análisis proximal indicó que la composición contenía 84,6 Kcal, 19,3 g de carbohidratos y 1,4 g de proteína por 100 g de bebida. Conclusiones: la bebida probiótica de quinua fue elaborada y puede ser considerada en el grupo de alimentos de origen vegetal, así como una bebida funcional, ya que los cultivos probióticos que contiene contribuyen al mantenimiento de la microbiota intestinal y previenen la aparición de enfermedades crónicas.

Expression, purification and characterization of a novel bis (hydroxyethyl) terephthalate hydrolase from Hydrogenobacter thermophilus / 生物工程学报

PET (polyethylene terephthalate) is one of the most important petrochemicals that is widely used in mineral water bottles, food and beverage packaging and textile industry. Because of its stability under environmental conditions, the massive amount of PET wastes caused serious environmental pollution. The use of enzymes to depolymerize PET wastes and upcycling is one of the important directions for plastics pollution control, among which the key is the depolymerization efficiency of PET by PET hydrolase. BHET (bis(hydroxyethyl) terephthalate) is the main intermediate of PET hydrolysis, its accumulation can hinder the degradation efficiency of PET hydrolase significantly, and the synergistic use of PET hydrolase and BHET hydrolase can improve the PET hydrolysis efficiency. In this study, a dienolactone hydrolase from Hydrogenobacter thermophilus which can degrade BHET (HtBHETase) was identified. After heterologous expression in Escherichia coli and purification, the enzymatic properties of HtBHETase were studied. HtBHETase shows higher catalytic activity towards esters with short carbon chains such as p-nitrophenol acetate. The optimal pH and temperature of the reaction with BHET were 5.0 and 55 ℃, respectively. HtBHETase exhibited excellent thermostability, and retained over 80% residual activity after treatment at 80 ℃ for 1 hour. These results indicate that HtBHETase has potential in biological PET depolymerization, which may facilitate the enzymatic degradation of PET.

Advances in the structure and function of chitosanase / 生物工程学报

Chitosanases represent a class of glycoside hydrolases with high catalytic activity on chitosan but nearly no activity on chitin. Chitosanases can convert high molecular weight chitosan into functional chitooligosaccharides with low molecular weight. In recent years, remarkable progress has been made in the research on chitosanases. This review summarizes and discusses its biochemical properties, crystal structures, catalytic mechanisms, and protein engineering, highlighting the preparation of pure chitooligosaccharides by enzymatic hydrolysis. This review may advance the understandings on the mechanism of chitosanases and promote its industrial applications.

Quantity - but not diversity - of secreted peptides and proteins increases with age in the tree frog Pithecopus nordestinus

Amphibians inhabit the terrestrial environment, a conquest achieved after several evolutionary steps, which were still insufficient to make them completely independent of the aquatic environment. These processes gave rise to many morphological and physiological changes, making their skin (and cutaneous secretion) rich in bioactive molecules. Among the tree frogs, the secretion is composed mainly of peptides; but alkaloids, proteins and steroids can also be found depending on the species. The most known class of biologically active molecules is the antimicrobial peptides (AMPs) that act against bacteria, fungi and protozoans. Although these molecules are well-studied among the hylids, AMPs ontogeny remains unknown. Therefore, we performed peptidomic and proteomic analyses of Pithecopus nordestinus (formerly Phyllomedusa nordestina) in order to evaluate the peptide content in post-metamorphosed juveniles and adult individuals. Methods: Cutaneous secretion of both life stages of individuals was obtained and analyzed by LC-MS/MS after reduction and alkylation of disulfide bonds or reduction, alkylation and hydrolysis by trypsin. Results: Differences in the TIC profile of juveniles and adults in both treatments were observed. Moreover, the proteomic data revealed known proteins and peptides, with slight differences in the composition, according to the life stage and the treatment. AMPs were identified, and bradykinin-potentiating peptides were observed in trypsin-treated samples, which suggests a protein source of such peptide (cryptide). Conclusion: In general, skin secretion contents were similar between juveniles and adults, varying in quantity, indicating that the different stages of life are reflected in the number of molecules and not on their diversity.(AU)

Discovery and functional verification of endogenous glucanases for scleroglucan hydrolysis in Sclerotium rolfsii / 生物工程学报

Scleroglucan is a high-molecular water-soluble microbial exopolysaccharide and mainly applied in the fields of petroleum, food, medicine and cosmetics. The high molecular weight of scleroglucan produced by microbial fermentation leads to low solubility, high viscosity and poor dispersibility, thus bringing a series of difficulties to extraction, preservation and application. It is important to explore suitable degradation method to adjust the molecular weight of scleroglucan for expanding its industrial application. Taking Sclerotium rolfsii WSH-G01 as a model strain, in which functional annotations of the glucanase genes were conducted by whole genome sequencing. Based on design of culture system for culture system for differential expression of β-glucanase, endogenous β-glucanase genes in S. rolfsii WSH-G01 were excavated by transcriptomics analysis. Functions of these potential hydrolases were further verified. Finally, 14 potential endogenous hydrolase genes were obtained from S. rolfsii. After heterologous overexpression in Pichia pastoris, 10 soluble enzymes were obtained and 5 of them had the activity of laminarin hydrolysis by SDS-PAGE and enzyme activity analysis. Further investigation of the 5 endogenous hydrolases on scleroglucan degradation showed that enzyme GME9860 has positive hydrolysis effect. The obtained results provide references not only for obtaining low and medium molecular weight of scleroglucan with enzymatic hydrolysis, but also for producing different molecular weight of scleroglucan during S. rolfsii fermentation process with metabolic engineering.

Progress in detoxification of inhibitors generated during lignocellulose pretreatment / 生物工程学报

Lignocellulose can be hydrolyzed by cellulase into fermentable sugars to produce hydrogen, ethanol, butanol and other biofuels with added value. Pretreatment is a critical step in biomass conversion, but also generates inhibitors with negative impacts on subsequent enzymatic hydrolysis and fermentation. Hence, pretreatment and detoxification methods are the basis of efficient biomass conversion. Commonly used pretreatment methods of lignocellulose are chemical and physic-chemical processes. Here, we introduce different inhibitors and their inhibitory mechanisms, and summarize various detoxification methods. Moreover, we propose research directions for detoxification of inhibitors generated during lignocellulose pretreatment.

Application of immobilized glycosidase in the synthesis of glycoside compounds / 生物工程学报

Glycoside compounds are widely used in medicine, food, surfactant, and cosmetics. The glycosidase-catalyzed synthesis of glycoside can be operated at mild reaction conditions with low material cost. The glycosidase-catalyzed processes include reverse hydrolysis and transglycosylation, appropriately reducing the water activity in both processes may effectively improve the catalytic efficiency of glucosidase. However, glucosidase is prone to be deactivated at low water activity. Thus, glucosidase was immobilized to maintain its activity in the low water activity environment, and even in neat organic solvent system. This article summarizes the advances in glycosidase immobilization in the past 30 years, including single or comprehensive immobilization techniques, and immobilization techniques combined with genetic engineering, with the aim to provide a reference for the synthesis of glycosides using immobilized glycosidases.

Cultivable cellulolytic fungi isolated from the gut of Amazonian aquatic insects

Fungos filamentosos tem sido alvo de estudos de bioprospecção devido à sua grande eficiencia em produzir enzimas extracelulares, as quais tem grande potencial para uso em bioindústrias. Neste estudo, fungos filamentosos foram isolados do intestino de larvas de insetos aquáticos da Amazônia, para avaliar sua atividade celulolítica. Foram coletadas 69 larvas de insetos aquáticos fragmentadores de três gêneros: Phylloicus (Trichoptera: Calamoceratidae), Triplectides (Trichoptera:Leptoceridae) e Stenochironomus (Diptera: Chironomidae) em dez igarapés de uma área protegida na Amazônia central brasileira. O crescimento dos fungos isolados foi feito em meio de cultura Ágar Batata Dextrose (BDA). Os isolados fúngicos foram transferidos para o meio sintético com Carboximetil celulose e utilizou-se vermelho Congo para determinar o índice enzimático. O halo de hidrólise, indicando a produção de celulases, foi observado em 175 isolados fúngicos (70% do total), dos quais 25 tiveram um índice enzimático ≥ 2,0 e pertencem a sete gêneros fúngicos. Os táxons fúngicos Cladosporium, Gliocephalotrichum, Penicillium, Pestalotiopsis, Talaromyces, Trichoderma e Umbelopsis foram isolados dos intestinos das larvas de Phylloicus, Triplectides e Stenochironomus e são tradicionalmente utilizados em aplicações biotecnológicas. Os resultados indicam um potencial celulolítco destes fungos associados ao intestino de insetos aquáticos amazônicos. (AU)

Collagen as a source of bioactive peptides: a bioinformatics approach

BACKGROUND: Collagen is the most abundant protein in animals and can be obtained from residues of the food industry. Its hydrolysate has many desirable properties that make it suitable as an additive in foods and cosmetics, or as a component of scaffold materials to be used in biomedicine. RESULTS: We report here the characterization of type I collagen from five different sources, namely bovine, porcine, chicken, trout and salmon, as well as their hydrolysates by means of bioinformatics tools. As expected, the results showed that bovine and porcine collagen, as well as trout and salmon collagen, can be used interchangeably due to their high identity. This result is consistent with the evolution of proteins with highly identical sequences between related species. Also, 156 sequences were found as potential bioactive peptides, 126 from propeptide region and 30 from the central domain, according to the comparison with reported active sequences. CONCLUSIONS: Collagen analysis from a bioinformatic approach allowed us to classify collagen from 5 different animal sources, to establish its interchangeability as potential additive in diverse fields and also to determine the content of bioactive peptides from its in silico hydrolysis.

Cometabolic biodegradation of quizalofop-p-ethyl by Methylobacterium populi YC-XJ1 and identification of QPEH1 esterase

BACKGROUND: Quizalofop-p-ethyl (QPE), a unitary R configuration aromatic oxyphenoxypropionic acid ester (AOPP) herbicide, was widely used and had led to detrimental environmental effects. For finding the QPEdegrading bacteria and promoting the biodegradation of QPE, a series of studies were carried out. RESULTS: A QPE-degrading bacterial strain YC-XJ1 was isolated from desert soil and identified as Methylobacterium populi, which could degrade QPE with methanol by cometabolism. Ninety-seven percent of QPE (50 mg/L) could be degraded within 72 h under optimum biodegradation condition of 35°C and pH 8.0. The maximum degradation rate of QPE was 1.4 mg/L/h, and the strain YC-XJ1 exhibited some certain salinity tolerance. Two novel metabolites, 2-hydroxy-6-chloroquinoxaline and quinoxaline, were found by high-performance liquid chromatography/mass spectroscopy analysis. The metabolic pathway of QPE was predicted. The catalytic efficiency of strain YC-XJ1 toward different AOPPs herbicides in descending order was as follows: haloxyfop-pmethyl ≈ diclofop-methyl ≈ fluazifop-p-butyl N clodinafop-propargyl N cyhalofop-butyl N quizalofop-p-ethyl N fenoxaprop-p-ethyl N propaquizafop N quizalofop-p-tefuryl. The genome of strain YC-XJ1 was sequenced using a combination of PacBio RS II and Illumina platforms. According to the annotation result, one α/ß hydrolase gene was selected and named qpeh1, for which QPE-degrading function has obtained validation. Based on the phylogenetic analysis and multiple sequence alignment with other QPE-degrading esterases reported previously, the QPEH1 was clustered with esterase family V. CONCLUSION: M. populi YC-XJ1 could degrade QPE with a novel pathway, and the qpeh1 gene was identified as one of QPE-degrading esterase gene.

Single cell oil production by a novel yeast Trichosporon mycotoxinivorans for complete and ecofriendly valorization of paddy straw

Background: Oleaginous yeasts can be grown on different carbon sources, including lignocellulosic hydrolysate containing a mixture of glucose and xylose. However, not all yeast strains can utilize both the sugars for lipogenesis. Therefore, in this study, efforts were made to isolate dual sugar-utilizing oleaginous yeasts from different sources. Results: A total of eleven isolates were obtained, which were screened for their ability to utilize various carbohydrates for lipogenesis. One promising yeast isolate Trichosporon mycotoxinivorans S2 was selected based on its capability to use a mixture of glucose and xylose and produce 44.86 ± 4.03% lipids, as well as its tolerance to fermentation inhibitors. In order to identify an inexpensive source of sugars, nondetoxified paddy straw hydrolysate (saccharified with cellulase), supplemented with 0.05% yeast extract, 0.18% peptone, and 0.04% MgSO4 was used for growth of the yeast, resulting in a yield of 5.17 g L−1 lipids with conversion productivity of 0.06 g L−1 h−1 . Optimization of the levels of yeast extract, peptone, and MgSO4 for maximizing lipid production using Box­Behnken design led to an increase in lipid yield by 41.59%. FAME analysis of single cell oil revealed oleic acid (30.84%), palmitic acid (18.28%), and stearic acid (17.64%) as the major fatty acids. Conclusion: The fatty acid profile illustrates the potential of T. mycotoxinivorans S2 to produce single cell oil as a feedstock for biodiesel. Therefore, the present study also indicated the potential of selected yeast to develop a zero-waste process for the complete valorization of paddy straw hydrolysate without detoxification

Reducción de proteínas y glucosa por reacción de Maillard en leche con lactosa hidrolisada / Protein and glucose reduction by Maillard reaction in milk with hydrolyzed lactose

Se evaluó el efecto de la temperatura sobre la desnaturalización de proteínas y la reacción de Maillard en leche entera y descremada con lactosa hidrolizada. Las leches hidrolizadas se trataron térmicamente a 100, 110, 120 y 130 °C durante un período de 1 hora y se midió la concentración de glucosa, el grado de pardeamiento y la desnaturalización de proteínas. El grado de dorado en la leche entera varió de 14.4 (100 °C) a 42.6 (130 °C). Para la leche descremada fue de 20.2 (100 °C) a 38.0 (130 °C). La concentración de glucosa en leche entera (47% p/v) y en leche descremada (41% p/v) después del tratamiento térmico (130 °C) mostró una reducción significativa en relación con el control (25 °C). El efecto de la temperatura en la desnaturalización de proteínas en leche entera y descremada en relación con el control (25 °C) fue del 100%. La leche tratada térmicamente con lactosa hidrolizada promovió la desnaturalización de proteínas con un aumento del pardeamiento característico de la reacción de Maillard, lo que afectó la calidad nutricional.

The effect of temperature in protein denaturation and Maillard reaction in whole and skim milk with hydrolyzed lactose was evaluated. Hydrolyzed milk was thermally treated at 100, 110, 120 and 130 °C over a period of 1 hour and glucose concentration, browning degree and protein denaturation were measured. The browning degree in whole milk varied from 14.42 (100 °C) to 42.63 (130 °C) and 20.21 (100 °C) to 38.03 (130 °C) in skim milk. Glucose concentration in whole milk (47% - w/v) and skim milk (41% - w/v) after heat treatment (130 °C) showed a significant reduction in relation to the control (25 °C). The temperature effect in protein denaturation in whole and skim milk in relation to the control (25 °C) was 100%. Thermally treated milk with hydrolyzed lactose promoted protein denaturation with increasing browning characteristic of the Maillard reaction, thus affecting the nutritional quality.

Development and validation of a stability indicating high performance liquid chromatography method for trimethobenzamide

A simple, accurate, precise and robust stability indicating RP-HPLC assay method has been developed for the estimation of trimethobenzamide in stress sample. An isocratic separation of trimethobenzamide was achieved on Kromasil 100 C-18 column (250 X 4.6mm, 5µ) with a flow rate of 1.0 ml/min and by using a photodiode array detector to detect the analyte at 213nm. The optimized mobile phase consisted of methanol: ammonium formate (44:56, v/v). The drug was subjected to different forced degradation conditions according to ICH guidelines including acid, base, neutral hydrolysis, oxidation, photolysis and thermal degradation. Degradation products were found only in basic and oxidative degradation conditions. All the degradation products got eluted in an overall analytical run time of 12min. The developed analytical method has been validated according to the ICH guidelines. Response of trimethobenzamide was linear over the concentration range of 0.5-50µg/mL (r2 = 0.999). Accuracy was found to be in between 94.03% to 100.39%. Degradation products resulting from the stress studies did not interfere with the detection of the analyte.

Effect of drying methods on the powder and compaction properties of microcrystalline cellulose derived from Gossypium herbaceum

The effect of drying method, a process variable, on the powder and compaction properties of microcrystalline cellulose (MCC) obtained from the partial acid hydrolysis of bleached alpha (α) cellulose content of matured linters of Gossypium herbaceum (GH) was investigated. A portion of the wet MCC obtained was fluid bed dried at 60 ± 1 ºC, inlet air of 30 m3 min-1 for 3 h (coded MCC-GossF). The second portion was lyophilized at - 45 ± 2 ºC for 6 h (coded MCC-GossL). The physicochemical, scanning electron micrographs, X ray diffraction patterns and micromeritic properties of the derived MCCs were determined using standard methods. The cohesiveness and compactibility of the powders were investigated using Kawakita model while the deformation and compressibility pattern were determined using Heckel model. Avicel® PH 102 (AV-102) was used as comparing standard. Ash values of < 2%, pH (6.54 ± 0.23 to 6.58 ± 0.08), degree of polymerization, DP (231.50) was obtained. MCC-GossF had higher moisture content, swellability, better flow indices, and lesser porosity than MCC-GossL. Kawakita model demonstrated good consolidation and compactibility for both powders. Compacts of MCC-GossL were significantly (p < 0.05) harder than those of MCC-GossF. Heckel analysis demonstrated good compressibility and deformation pattern that was comparable with AV-102. Compacts of MCC-GossL had better mechanical and tablet compression properties than MCC-GossF

Comparison of Lactic Acid Production by L. casei in Batch, Fed-batch and Continuous Cultivation, Testing the use of Feather Hydrolysate as a Complex Nitrogen Source

Abstract A comprehensive comparison of the main fermentation parameters, productivity, yield and final L-lactic acid concentration, obtained through batch, fed-batch and continuous cultivations using Lactobacillus casei CCDM 198 and a model cultivation medium was carried out. Using this data, a pulse-feed fed-batch process was established for testing chicken feather hydrolysate as a replacement for all complex nitrogen sources (yeast and beef extracts and peptone) in the medium. As comparably high values of productivity (about 4.0 g/L/h) and yield (about 98 %) were reached under all cultivation conditions, the maximum final L-lactic acid concentration (116.5 g/L), as achieved through pulse-feed fed-batch fermentation, was chosen as the most important criterion for process selection. Fed-batch cultivation with chicken feather hydrolysate as both a complex nitrogen source and a neutralizing agent for maintaining constant culture pH yielded half the concentration of L-lactic acid compared to the model medium. We demonstrate here that chicken feather hydrolysate has potential for use in the production of L-lactic acid but its utilization requires further optimization

Progress in applying surfactants to lignocellulose hydrolysis for sugar production / 生物工程学报

Lignocellulose is a major biomass resource for the production of biofuel ethanol. Due to its abundance, environmental friendliness and renewability, the utilization of lignocellulose is promising to solve energy shortage. Surfactant can effectively promote the enzymatic hydrolysis of lignocellulose. By discussing the influence and mechanism of different surfactants on the enzymatic hydrolysis, we provide references for finding appropriate surfactants in enzymatic hydrolysis process.

Recent progress in 2-haloacid dehalogenases / 生物工程学报

2-Haloacid dehalogenases (EC 3.8.1.X) catalyze the hydrolytic dehalogenation of 2-haloacids, releasing halogen ions and producing corresponding 2-hydroxyacids. The enzymes not only degrade xenobiotic halogenated pollutants, but also show wide substrate profile and astonishing efficiency for enantiomer resolution, making them valuable in environmental protection and the green synthesis of optically pure chiral compounds. A variety of 2-haloacid dehalogenases have been biochemically characterized so far. Further studies have been made in protein crystal structures and catalytic mechanisms. Here, we review the recent progresses of 2-haloacid dehalogenases in their source, protein structures, reaction mechanisms, catalytic properties and application. We also suggest further research directions for 2-haloacid dehalogenase.

Assessment of wasteland derived biomass for bioethanol production

Background: The bioethanol produced from biomass is a promising alternative fuel. The lignocellulose from marginal areas or wasteland could be a promising raw material for bioethanol production because it is present in large quantities, is cheap, renewable and has favorable environmental properties. Despite these advantages, lignocellulosic biomass is much more difficult to process than cereal grains, due to the need for intensive pretreatment and relatively large amounts of cellulases for efficient hydrolysis. Therefore, there is a need to develop an efficient and cost-effective method for the degradation and fermentation of lignocellulosic biomass to ethanol. Results: The usefulness of lignocellulosic biomass from wasteland for the production of bioethanol using pretreatment with the aid of ionic liquids of 1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium chloride was evaluated in this study. The pretreatment process, enzymatic hydrolysis and alcoholic fermentation lasted a total of 10 d. The largest amounts of bioethanol were obtained from biomass originating from agricultural wasteland, in which the dominant plant was fireweed (Chamaenerion angustifolium) and from the field where the common broom (Cytisus scoparius) was the dominant. Conclusions: The plants such as fireweed, common broom, hay and goldenrod may be useful for the production of liquid biofuels and it would be necessary in the further stage of research to establish and optimize the conditions for the technology of ethyl alcohol producing from these plant species. Enzymatic hydrolysis of biomass from agricultural wastelands results in a large increase in fermentable sugars, comparable to the enzymatic hydrolysis of rye, wheat, rice or maize straw.

Solid state fermentation to obtain vegetable products bio-enriched with isoflavone aglycones using lactic cultures / Fermentación en sustrato sólido utilizando cultivos lácticos para la obtención de productos vegetales bioenriquecidos con isoflavonas agliconas

The consumption of soybean isoflavones (IS) is associated with several beneficial properties on human health. Some lactic acid bacteria possess ß-glucosidase enzyme, that allows to obtain the active form of IS (aglycone). The solid state fermentation (SSF) has received great attention in the last years in order to obtain several valuable compounds. SSF, using soybean as substrate and Lactobacillus rhamnosus CRL 981 as starter, was studied in the present work. Sucrose was added into soybean paste to study the effect on the behavior of the selected strain. The development of L. rhamnosus CRL 981 through pH and recount measures, sugar intake, organic acid production, ß-glucosidase activity and IS conversion were analyzed. No significant differences in growth and acidity were observed between soybean pastes with and without sucrose added, but the production of lactic acid was higher in the latter paste. The ß-glucosidase activity was detected in both pastes and the complete hydrolysis of IS at 12 h of fermentation was observed. Also, this strain was able to increase the free amino acids in soybean paste. SSF, using soybean as substrate and L. rhamnosus CRL 981 as starter culture, is an alternative process to obtain a soybean product bio-enriched in active IS with attractive nutritional characteristics.

El consumo de isoflavonas de soja (IS) está asociado a diversos beneficios para la salud humana. Ciertas bacterias lácticas poseen la enzima ß-glucosidasa, que permite obtener la forma bioactiva (agliconas) de las IS. La fermentación en sustrato sólido (FSS) ha recibido gran atención en los últimos anos debido a sus numerosas ventajas, y permite la obtención de productos con valor agregado. En el presente trabajo se estudió la FSS utilizando soja como sustrato y Lactobacillus rhamnosus CRL981 como cultivo iniciador. Con el fin de estudiar el efecto de una fuente de carbono externa sobre el comportamiento de la cepa seleccionada, se adicionó sacarosa a la pasta de soja. Se evaluó el crecimiento de L. rhamnosus CRL 981 a través de medidas de pH y recuento en placa. Además, se analizó el consumo de azúcares, producción de ácidos orgánicos, actividad ß-glucosidasa y conversión de IS. No se observaron diferencias significativas en el crecimiento y acidez entre las pastas de soja sin adición de sacarosa y con ella, sin embargo, la producción de ácido láctico fue mayor en esta última. La actividad de ß-glucosidasa se detectó en ambas pastas y se observó la hidrólisis completa de IS a las 12 h de fermentación. Además, esta cepa fue capaz de aumentar los aminoácidos libres en la pasta de soja. La FSS, utilizando soja como sustrato y L. rhamnosus CRL 981 como cultivo iniciador, es un proceso alternativo para obtener un producto de soja bioenriquecido en IS bioactivas con características nutricionales atractivas.

Improvement of ethanol production from birch and spruce pretreated with 1-H-3-methylmorpholinium chloride

Background: Pretreatment is the critically important step for the production of ethanol from lignocelluloses. In this study, hardwood birch (Betula pendula) and softwood spruce (Norway spruce) woods were pretreated with a newly synthesized morpholinium ionic liquid, 1-H-3-methylmorpholinium chloride ([HMMorph][Cl]), followed by enzymatic hydrolysis and fermentation to ethanol. Results: [HMMorph][Cl] was synthesized using inexpensive raw materials, i.e., hydrochloric acid and N-methyl morpholine, following a simple process. The influence of pretreatment time (2, 3, 5, and 8 h) and temperature (120 and 140°C) in terms of hydrolysis efficiency was investigated. Glucose yields from enzymatic hydrolysis were improved from 13.7% to 45.7% and 12.9% to 51.8% after pretreatment of birch and spruce woods, respectively, under optimum pretreatment conditions (i.e., at 140°C for 3 h) as compared to those from pristine woods. Moreover, the yields of ethanol production from birch and spruce were increased to 34.8% and 44.2%, respectively, while the yields were negligible for untreated woods. Conclusions: This study demonstrated the ability of [HMMorph][Cl] as an inexpensive agent to pretreat both softwood and hardwood.