Genetic diversity of N-fixing and plant growth-promoting bacterial community in different sugarcane genotypes, association habitat and phenological phase of the crop.

This study aimed to evaluate the genetic diversity of bacterial community associated to different sugarcane genotypes, association habitat and phenological phase of the culture, as well as to isolate, to identify and to characterize your potential for plant growth-promoting. Root and rhizospheric soil samples from RB 92579 and RB 867515 varieties were collected at 120 and 300 days after regrowth (DAR). The diversity of bacterial was evaluated through of the 16S rRNA and nifH genes. We found greater genetic diversity in the root endophytic habitat at 120 DAR. We identify the genera Burkholderia sp., Pantoea sp., Erwinia sp., Stenotrophomonas sp., Enterobacter sp. and Pseudomonas sp. The genera Bacillus sp. and Dyella sp. were only identified in the variety RB 92579. We found indices above 50% for biological nitrogen fixation, production of indole acetic acid and phosphate solubilization, showing that the use of these bacteria in biotechnological products is very promising.

Characterization of lyophilized equine colostrum.

Foals require maternal colostrum in the first hours of life to prevent failure of transfer of passive immunity (FTIP). Innovative storage methods such as lyophilization may enable conservation of colostrum immunoglobulins by a differentiated process of dehydration. The current study aimed to compare the quality of equine colostrum after freezing and after the lyophilization process. Thirty-one pregnant Quarter Horse mares were used. The IgG concentration of frozen and lyophilized colostrum was determined by simple radial immunodiffusion (SRID) and Brix refractometry. The physical-chemical composition (pH, total protein (TP), fat, lactose, salts, total solids (TS), and density) of the samples was evaluated and the lyophilized colostrum reconstitution test was performed. There were no significant differences (P > 0.05) in the variables IgG, fat, lactose, salts, TS, density, and pH between samples measured before and after lyophilization. There was a significant difference (P < 0.05) between the Brix average and the TP of the frozen and lyophilized colostrum samples. Lyophilization resulted in a small reduction (6.55%) in the IgG concentration measured by SRID. A strong positive correlation was observed between colostrum density and IgG concentration by SRID (r = 0.76) and between Brix and IgG concentration by SRID (r = 0.77). In the reconstitution test, the lyophilized colostrum was easily rehydrated in water, with full dilution, and remained stable. Lyophilization could be an alternative for the conservation of mare colostrum, since it is a very efficient process for retaining the physicochemical characteristics of the product, with minimal loss, particularly of IgG.

Potencial antioxidante de hidrolisados proteicos obtidos a partir de caseinato de ruminantes pela ação de proteases comerciais / Potential antioxidant of protein hydrolysates obtained from ruminant caseinate by the action of commercial proteases

Introdução: a oxidação em sistemas biológicos está relacionada ao desenvolvimento de patologias em humanos. A ingestão de alimentos ricos em compostos químicos que exercem atividade antioxidante contribui para a prevenção e redução dos efeitos deletérios dos radicais livres formados no organismo. Peptídeos derivados das caseínas têm mostrado um elevado potencial como agentes antioxidantes. Objetivos: neste sentido, o presente estudo avaliou a atividade antioxidante de hidrolisados derivados de caseínas de leites das espécies bubalina, bovina e caprina, obtidos pela ação de diferentes proteases. Metodologia: inicialmente, as caseínas foram isoladas dos demais componentes do leite, depois foram submetidas ao processo de proteólise pelas enzimas bromelina, papaína, tripsina e neutrase, individualmente. A atividade antioxidante dos hidrolisados foi avaliada, através da capacidade de eliminação dos radicais: hidroxila (OH­Ë™), superóxido (O2­Ë™), 2,2 difenil-1-picrilhidrazil (DPPH˙), 2,2'azinobis-(3-ácido etilbenzotiazolino-6-sulfônico (ABTS˙), e quelante dos íons metálicos cobre (Cu2+) e ferro (Fe2+). Resultados: os resultados mostraram que a caseína bovina apresentou o menor (35,54%) grau de hidrólise e a caseína bubalina apresentou o maior (85,64%) grau de hidrólise pela ação da neutrase e bromelina após 480 minutos, respectivamente. O potencial para o sequestro dos radicais hidroxila variou entre 0 e 100%, superóxido superior a 80%, ABTS superior a 85%, DPPH entre 20 e 95% habilidade de quelar ferro entre 10 e 100% e cobre entre 14 e 80%. Conclusão: assim, a hidrólise das caseínas do leite bubalino, bovino e caprino foram capazes de produzir hidrolisados com elevado potencial antioxidante e que, mediante novos estudos, poderá vir ser incorporado em produtos alimentícios para o consumo humano.

Introduction: oxidation in biological systems is related to the development of pathologies in humans. The ingestion of foods rich in chemical compounds that exert antioxidant activity contributes to the prevention and reduction of the deleterious effects of free radicals formed in the body. Peptides derived from caseins have shown high potential as antioxidant agents. Objectives: the present study evaluated the antioxidant activity of casein hydrolysates derived from bubaline, bovine, and caprine milk obtained by the action of different proteases. Methodology: initially, the caseins were isolated from the other milk components, and then subjected to the proteolysis process by the enzymes bromelain, papain, trypsin and neutrase, individually. The antioxidant activity of the hydrolysates was evaluated, through the capacity of elimination of the radicals: hydroxyl (OH-˙), superoxide (O2-˙), 2,2 diphenyl-1-picrylhydrazyl (DPPH˙), 2,2'azinobis-(3-ethylbenzothiazolino-6-sulfonic acid (ABTS˙), and chelating of the metal ions copper (Cu2+) and iron (Fe2+). Results: the results showed that bovine casein showed the lowest (35.54%) degree of hydrolysis and bubaline casein showed the highest (85.64%) degree of hydrolysis by the action of neutrase and bromelin after 480 minutes, respectively. The potential for hydroxyl radical sequestration varied between 0 and 100%, superoxide higher than 80%, ABTS higher than 85%, DPPH between 20 and 95% and the ability to chelate iron between 10 and 100% and copper between 14 and 80%. Conclusion: thus, the hydrolysis of caseins from bubaline, bovine and goat milk were able to produce hydrolysates with high antioxidant potential and that, upon further studies, may be incorporated into food products for human consumption.

Antioxidant Activities of Chicken Egg White Hydrolysates Obtained by New Purified Protease of Aspergillus avenaceus URM 6706

Abstract Protein hydrolysates originating from egg white have already been reported to be bioactive and, among their biological activities, possess the antioxidant property that protects the body from early ageing and diseases linked to oxidation. Therefore, the objective of this work was to evaluate the antioxidant activity of hydrolysates obtained by the hydrolysis of egg white from hen poultry. The protease produced by Aspergillus avenaceus URM 6706 was purified and subsequently applied to hydrolysate the egg white, and the degree of hydrolysis was verified during the protease exposure time (4-24 h). The hydrolysis was intensified over time of exposure to the protease. It was possible to detect the antioxidant activities of eliminating the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) radical (ABTS•+) from 97% to 99% and 2,2-diphenyl-1-picrylhydrazyl (DPPH•) up to 27%, as well as the chelation of Cu2+ metal ions up to 62% and Fe2+ up to 54%. The elimination of ABTS•+ radical had a positive correlation with the degree of hydrolysis; however, all the other activities tested showed a negative correlation with the degree of hydrolysis. The results obtained suggest that the egg white of hen chicken represents a food source of animal origin with potential application in the functional food industry.

Bactérias diazotróficas associadas a raízes de cana-de-açúcar: solubilização de fosfato inorgânico e tolerância à salinidade / Diazotrophic bacteria associated to roots of sugarcane: inorganic phosphate solubilization and the salinity tolerance

O uso de micro-organismos na agricultura é uma alternativa amplamente pesquisada e disseminada, que busca a diminuição no uso de fertilizantes químicos com consequente redução da degradação do meio ambiente. O objetivo deste trabalho foi avaliar a capacidade de solubilização de fosfato inorgânico (SFI) e o crescimento bacteriano em meio de cultura livre de fonte nitrogenada sob diferentes concentrações de NaCl de isolados bacterianos diazotróficos, associados a raízes de plantas de cana-de-açúcar. Foram avaliados 30 isolados, 15 endofíticos de raiz e 15 da rizosfera. A seleção de bactérias SFI foi realizada em meio sólido contendo fosfato insolúvel, avaliando-se o índice de solubilização (IS). Para a avaliação da influência de sal sobre o crescimento bacteriano em meio livre de nitrogênio, as bactérias foram cultivadas em meio NFb semi-sólido, acrescido de 0; 2,5; e 5% de NaCl. Foi possível observar que 90% dos isolados diazotróficos foram capazes de solubilizar fosfato inorgânico e que os isolados da rizosfera apresentaram os maiores IS. Quanto ao crescimento em meio NFb, foi observado que na ausência do sal todas as bactérias foram capazes de crescer. Contudo, 60% dos isolados foram capazes de crescer em meio NFb acrescido de 2,5% de NaCl e 17% em 5% de NaCl. Quando considerado o nicho do qual as bactérias foram isoladas, observou-se que as bactérias diferiram quanto à capacidade de crescer em meio NFb sob diferentes concentrações de NaCl. Os resultados permitem inferir que esses isolados bacterianos têm aplicações tecnológicas como promotores de crescimento vegetal, inclusive em solos salinos.