Angel Valdez-Ortiz

Solid-state bioconversion of chickpea (Cicer arietinum L.) by Rhizopus oligosporus to improve total phenolic content, antioxidant activity and hypoglycemic functionality.

Abstract The objective of this investigation was to study the effect of time during solid state bioconversion (SSB) on total phenolic content (TPC), antioxidant activity (AoxA), and inhibitory properties against α-amylase and α-glucosidase of chickpea. Chickpea cotyledons were inoculated with a suspension of Rhizopus oligosporus and incubated at 35 °C for 24, 36, 48, 60, 72, 84, 96 and 108 h. The best time to produce bioprocessed chickpea (added with seed coats) flour with the highest AoxA was 108 h. SSB substantially increased TPC and AoxA of chickpea extracts in 2.78 and 1.80–1.94 times, respectively. At 36 and 96 h of fermentation, the SSB process improved in vitro α-amylase and α-glucosidase inhibition (AI and GI indexes) activities of chickpea extracts in 83 and 370%, respectively. SSB is a good strategy to enhance health-linked functionality of chickpea, due to improved TPC, AoxA and content of strong natural inhibitors of enzymes associated with diabetes.

Microalgae potential as a biogas source: current status, restraints and future trends

In recent years, the world energy demands have had a recurrent increase. For this reason the alternative to the fossil fuel resources are trend topics in investigation. Microalgae have been extensively studied as a source of biofuels and as one of the most promising alternatives in this new framework. One of the possibilities of obtaining renewable energy from microalgae is biogas production using anaerobic digestion process. This process is considered a significant component for biofuels and waste management, since represent an opportunity for energy generation using different wastewater products; also, the economic viability of microalgae liquid biofuel production could be improved. However, the anaerobic digestion of microalgae biomass is still not optimized because of the numerous technical limitations such as the microalgae characteristics, low carbon:nitrogen ratio, ammonia toxicity and even salinity. The present review summarizes and compares information concerning to anaerobic digestion of microalgal biomass and future directions for research. Besides, specific operational factors and potential inhibitory parameters of the process are analyzed and compared. Additionally, the paper covers the state or art concerning in methane production enhancement from algal biomass.

Valorisation of biodiesel production wastes: anaerobic digestion of residual Tetraselmis suecica biomass and co-digestion with glycerol.

One of the principal opportunity areas in the development of the microalgal biodiesel industry is the energy recovery from the solid microalgal biomass residues to optimise the fuel production. This work reports the cumulative methane yields reached from the anaerobic digestion of the solid microalgal biomass residues using different types of inocula, reporting also the improvement of biogas production using the co-digestion of microalgal biomass with glycerol. Results demonstrate that the solid microalgal biomass residues showed better biogas production using a mesophilic inoculum, reaching almost two-fold higher methane production than under thermophilic conditions. Furthermore, the solid microalgal biomass residues methane production rate showed an increase from 173.78 ± 9.57 to 438.46 ± 40.50 mL of methane per gram of volatile solids, when the co-digestion with glycerol was performed. These results are crucial to improve the energy balance of the biodiesel production from Tetraselmis suecica, as well as proposing an alternative way to treat the wastes derived from the microalgae biodiesel production.

Effects of outdoor cultures on the growth and lipid production of Phaeodactylum tricornutum using closed photobioreactors

One of the principal challenges for large scale production of microalgae is the high costs of biomass production. Aiming for minimize this problem, microalgal biodiesel production should focus on outdoors cultures, using available solar light and allowing lower energy cost process. Testing species that proved to be common and easy to culture may be a good approach in this process. The present work reports indoor-outdoor cultures of Phaeodactylum tricornutum using different bioreactors types, using cell growth, biochemical composition, and the profiles of the fatty acids produced as the parameters to test the optimization processes. The results show that the use of outdoor cultures is a good choice to obtain P. tricornutum biomass with a good potential for biodiesel production. The microalgae produced reached better growth efficiency, major lipid content and showed an increment in the percentage of saturated fatty acids (required on the biodiesel production) respect indoor cultures. These results are important to show the relevance of using outdoor cultures as a way to improve the efficiency and the energetic balance of the biodiesel production with P. tricornutum algae.

Functionomics of NCC mutations in Gitelman syndrome using a novel mammalian cell-based activity assay

Gitelman syndrome (GS) is an autosomal recessive salt-wasting tubular disorder resulting from loss-of-function mutations in the thiazide-sensitive NaCl cotransporter (NCC). Functional analysis of these mutations has been limited to the use of Xenopus laevis oocytes. The aim of the present study was, therefore, to analyze the functional consequences of NCC mutations in a mammalian cell-based assay, followed by analysis of mutated NCC protein expression as well as glycosylation and phosphorylation profiles using human embryonic kidney (HEK) 293 cells. NCC activity was assessed with a novel assay based on thiazide-sensitive iodide uptake in HEK293 cells expressing wild-type or mutant NCC (N59I, R83W, I360T, C421Y, G463R, G731R, L859P, or R861C). All mutations caused a significantly lower NCC activity. Immunoblot analysis of the HEK293 cells revealed that 1) all NCC mutants have decreased NCC protein expression; 2) mutant N59I, R83W, I360T, C421Y, G463R, and L859P have decreased NCC abundance at the plasma membrane; 3) mutants C421Y and L859P display impaired NCC glycosylation; and 4) mutants N59I, R83W, C421Y, C731R, and L859P show affected NCC phosphorylation. In conclusion, we developed a mammalian cell-based assay in which NCC activity assessment together with a profiling of mutated protein processing aid our understanding of the pathogenic mechanism of the NCC mutations.

Enhancement of nutritional properties, and antioxidant and antihypertensive potential of black common bean seeds by optimizing the solid state bioconversion process

Abstract The aim of this work was to obtain a functional flour with enhanced nutritional properties, and antioxidant and antihypertensive potential from black bean seeds by optimizing the solid state bioconversion (SSB) process using a Rhizopus oligoporus strain. Response surface methodology was applied as optimization technique. A central composite experimental design with two factors [fermentation temperature (FT) = 30–40 °C/fermentation time (Ft) = 6–108 h] and five levels was used (13 treatments). The bioprocessed cotyledons from each treatment were dried, milled, and blended with its previously dried-milled seed coats. The best combination FT/Ft of SSB to obtain the functional flour was 38 °C/100 h. SSB increased the calculated protein efficiency ratio (from 1.59 to 2.40), antioxidant activity (from 13 948 to 22 733 µmol ET/100 g, dw), total phenolic compounds (TPC) (from 190 to 432 mg EGA/100 g, dw) and antihypertensive potential (IC50 from 95.57 to 0.0321 µg/mL). SSB is an effective strategy to improve the TPC of common beans for enhanced functionality.

Residual biomasses and protein hydrolysates of three green microalgae species exhibit antioxidant and anti-aging activity

It is widely recognized that microalgae represent a promising strategy in the development of next-generation biofuels; however, their economic viability remains questionable. Several studies have shown microalgal biomass is a relatively unexplored source of natural components with nutraceutical activities; indeed, some authors state that the remaining residue after oil extraction from the microalgae biomass, known as microalgae residual biomass (MRB), could have outstanding biological activities. Therefore, in the present study, we analyzed the antioxidant capacity and anti-aging potential of MRB and protein hydrolysates of three green microalgae species: Dunaliella tertiolecta, Tetraselmis suecica, and Nannochloropsis sp. Antioxidant capacity, determined through oxygen radical absorbance capacity (ORAC), radical cation activity (ABTS), and radical scavenging activity (DPPH), of the three MRBs was good overall, with D. tertiolecta and Nannochloropsis having the highest antioxidant capacity. Interestingly, their protein hydrolysates showed markedly higher antioxidant capacities than their MRBs at the concentrations tested. Anti-aging potential, determined by the inhibition of the activity of two extracellular matrix-degrading enzymes, elastase and hyaluronidase, was found to be higher in D. tertiolecta and Nannochloropsis biomasses for anti-elastase activity; however, no significant differences between microalgae species were found in anti-hyaluronidase activity. For the protein hydrolysates, Nannochloropsis had the highest anti-elastase and anti-hyaluronidase activity. In conclusion, selected MRBs and their protein hydrolysates exhibited a good antioxidant capacity and/or anti-aging potential overall, indicating the economical importance of MRBs in the nutraceutical and nutricosmetic industries. Overall, this study contributes to convert microalgae biofuel production into a more sustainable and economically feasible process, through the comprehensive utilization of residual biomass.

Histopathological Changes in Third-Instar and Adult Anastrepha ludens (Diptera: Tephritidae) After in vitro Heat Treatment

ABSTRACT. The Mexican fruit fly, Anastrepha ludens Loew (Diptera: Tephritidae), is one of the most harmful pests of mango causing direct damage by oviposition on the fruit pulp. Mango for export is subjected to hydrothermal treatment as a quarantine method for the control of this pest, but exposure to heat for long periods of time reduces considerably the quality and shelf-life of treated fruit. The aim of this work was to study morphological changes of third-instar larvae and adults of A. ludens after in vitro exposure to high temperature at sublethal times. A heating block system was used to expose larvae at 46.1°C for 19.6 and 12.9 min, producing 94.6 and 70% mortality, respectively. Treated larvae were processed for optical microscopy. A fraction of surviving treated larvae was separated into containers with artificial diet to allow development into adults. Adult sexual organs were dissected and processed for transmission electron microscopy analysis. Results showed that 94.6% of the treated larvae died at 46.1°C for 19.6 min and none of the surviving larvae eclosed to adulthood, as they developed as malformed puparia. For the in vitro treatment at 46.1°C during 12.9 min, 70% of the treated larvae died and only 3.75% reached the adult stage, but ultrastructural damage in the male testes and in the female ovaries was observed. Additionally, 11.1% of the adult flies from the in vitro treatment also showed wing malformation and were incapable of flying. The analysis showed that surviving flies were unable to reproduce.

Mortality in Patients with Chronic Renal Disease without Health Insurance in Mexico: Opportunities for a National Renal Health Policy

Introduction Despite a systematic increase in the coverage of patients with end-stage renal disease (ESRD) who have received dialytic therapies and transplantation over the past 2 decades, the Mexican health system currently still does not have a program to provide full coverage of ESRD. Our aim was to analyze mortality in patients with ESRD without health insurance. Methods This was a prospective cohort study of 850 patients with advanced chronic kidney disease (CKD). Risk factors associated with death were calculated using a Coxs proportional hazards model. We used the statistical package SPSS version 22.0 for data analysis. Results The mean age of patients was 44.8 ± 17.2 years old. At the time of hospital admission, 87.6% of the population did not have a social security program to cover the cost of renal replacement treatment, and 91.3% of families had an income below US

Establishment of an efficient genetic transformation method in Dunaliella tertiolecta mediated by Agrobacterium tumefaciens

300 per month. During the 3 years of the study, 28.8% of the cohort patients were enrolled in 1 of Mexicos social security programs. The 3-year mortality rate was of 56.7% among patients without access to health insurance, in contrast to 38.2% of patients who had access to a social security program that provided access to renal replacement therapy (P < 0.001). Risk factor analysis revealed that not having health insurance increased mortality (risk ratio: 2.64, 95% confidence intervals: 1.84−3.79; P = 0.001). Conclusion Mexico needs a coordinated National Kidney Health and Treatment Program. A program of this nature should provide the basis for an appropriate educational and intervention strategy for early detection, prevention, and treatment of patients with advanced chronic kidney disease.