Legumes are affected by biotic factors such as insects, molds, bacteria, and viruses. These plants can produce many different molecules in response to the attack of phytopathogens. Protease inhibitors (PIs) are proteins produced by legumes that inhibit the protease activity of phytopathogens. PIs are known to reduce nutrient availability, which diminishes pathogen growth and can lead to the death of the pathogen. PIs are classified according to the specificity of the mechanistic activity of the proteolytic enzymes, with serine and cysteine protease inhibitors being studied the most. Previous investigations have reported the efficacy of these highly stable proteins against diverse biotic factors and the concomitant protective effects in crops, representing a possible replacement of toxic agrochemicals that harm the environment.

Abstract:In the past two decades, Candida species have become the second leading cause of invasive mycosis in immunocompromised patients.In order to colonize their hosts, these microorganisms express adhesins and cell wall proteins that allow them to adhere and neutralize the reactive oxygen species produced by phagocytic cells during the respiratory burst. However, the precise mechanism by which Candida cell wall proteins change their expression in response to oxidative stress has not been described. In an attempt to understand this change in response to oxidative stress, in this study, three Candida species, namely, C. albicans, C. glabrata and C. krusei, were exposed to increasing concentrations of H 2 O 2 and induced cell wall proteins were identified by two-dimensional gel electrophoresis and peptide mass fingerprinting. Sequence analysis of differential proteins led to the identification of two heat-shock proteins in C. albicans, two enolases in C. glabrata and one enolase in C. krusei. Enolases may be involved in the protection of pathogenic cells against oxidative stress as suggested by the decrease in their expression when they were exposed to high concentrations of H 2 O 2. To our knowledge, this is the first demonstration that expression of these proteins changes in response to oxidative stress in different Candida species. This knowledge can eventually facilitate both an early diagnosis and a more efficient treatment of this mycosis.

Astaxanthin (ASX) is a xanthophyll pigment considered as a nutraceutical with high antioxidant activity. Several clinical trials have shown the multiple health benefits of this molecule; therefore, it has various pharmaceutical industry applications. Commercial astaxanthin can be produced by chemical synthesis or through biosynthesis within different microorganisms. The molecule produced by the microorganisms is highly preferred due to its zero toxicity and superior therapeutic properties. However, the biotechnological production of the xanthophyll is not competitive against the chemical synthesis, since the downstream process may represent 70–80% of the process production cost. These operations denote then an opportunity to optimize the process and make this alternative more competitive. Since ASX is produced intracellularly by the microorganisms, high investment and high operational costs, like centrifugation and bead milling or high-pressure homogenization, are mainly used. In cell recovery, flocculation and flotation may represent low energy demanding techniques, whereas, after cell disruption, an efficient extraction technique is necessary to extract the highest percentage of ASX produced by the cell. Solvent extraction is the traditional method, but large-scale ASX production has adopted supercritical CO2 (SC-CO2), an efficient and environmentally friendly technology. On the other hand, assisted technologies are extensively reported since the cell disruption, and ASX extraction can be carried out in a single step. Because a high-purity product is required in pharmaceuticals and nutraceutical applications, the use of chromatography is necessary for the downstream process. Traditionally liquid-solid chromatography techniques are applied; however, the recent emergence of liquid-liquid chromatography like high-speed countercurrent chromatography (HSCCC) coupled with liquid-solid chromatography allows high productivity and purity up to 99% of ASX. Additionally, the use of SC-CO2, coupled with two-dimensional chromatography, is very promising. Finally, the purified ASX needs to be formulated to ensure its stability and bioavailability; thus, encapsulation is widely employed. In this review, we focus on the processes of cell recovery, cell disruption, drying, extraction, purification, and formulation of ASX mainly produced in Haematococcus pluvialis, Phaffia rhodozyma, and Paracoccus carotinifaciens. We discuss the current technologies that are being developed to make downstream operations more efficient and competitive in the biotechnological production process of this carotenoid.

El uso de microorganismos promotores del crecimiento, tiene grandes beneficios, los que ayudan a disminuir el uso excesivo de fertilizantes y pesticidas usados en la producción agrícola. Los objetivos fueron aislar, caracterizar y evaluar en campo cepas del género Bacillus spp., en el rendimiento de maíz forrajero. El estudio fue realizado en el campo experimental de la Facultad de Agricultura y Zootecnia en la Universidad Juárez del Estado de Durango en la región de la Comarca Lagunera, ubicada en el norte de México, durante 2018. Se aislaron y se identificaron cepas de Bacillus spp., a partir de raíces de plantas de zacate Johnson (Sorghum halepense), maíz (Zea mays) y sorgo (Sorghum bicolor), preseleccionadas de acuerdo a la capacidad para fijar nitrógeno y caracterizadas por secuenciación del gen 16S rDNA. Fueron identificadas dos cepas de Bacillus amyloliquefaciens y tres más de Bacillus subtilis. Posteriormente, evaluadas en campo durante los ciclos primavera-verano (P-V) y otoño-invierno (O-I) del año 2018, en dos híbridos de maíz (Galáctico y AG 614). La inoculación con la cepa Bacillus amyloliquefaciens favoreció un buen resultado para peso fresco de la planta, peso seco, diámetro de tallo, número de elotes, peso fresco de raíz y en longitud de la raíz; mientras que Bacillus subtilis, mejor en peso fresco de raíz respecto al testigo. Con referencia al área foliar y porcentaje de proteína cruda, no se observó diferencia significativa entre los tratamientos con resultados similares al tratamiento químico. Finalmente, para diámetro de raíz, el resultado más favorable se presentó con el tratamiento químico. Los mejores resultados fueron encontrados durante el ciclo P-V.

Defatted soybean flour is generated during the oil extraction process of soybean, and it has a protein content of ~50%. On the other hand, an alkaline solution of NaOH is produced during the electrolysis process of NaCl in a novel method used to make a potent disinfectant/antiseptic (HOCl). In the present work, we suggest using these two products to produce soy protein isolate (SPI), aiming to create an industrial symbiosis. A Box–Behnken experimental design was executed, and a surface response analysis was performed to optimize temperature, alkaline solution, and time used for SPI extraction. The SPI produced at optimal conditions was then characterized. The experimental results fit well with a second-order polynomial equation that could predict 93.15% of the variability under a combination of 70 °C, alkaline solution 3 (pH 12.68), and 44.7 min of the process. The model predicts a 49.79% extraction yield, and when tested, we obtained 48.30% within the confidence interval (46.66–52.93%). The obtained SPI was comparable in content and structure with a commercial SPI by molecular weight and molecular spectroscopy characterization. Finally, the urease activity (UA) test was negative, indicating no activity for trypsin inhibitor. Based on the functional properties, the SPI is suitable for food applications.