A deficiência hídrica é considerada um fator que produz danos significativos durante o período de estabelecimento e de crescimento dos plantios. O objetivo deste estudo foi investigar características morfofisiológicas e bioquímicas de folhas de mudas de seringueira em resposta à deficiência hídrica e, posterior, reidratação. Plantas jovens de Hevea brasiliensis do clone RRIM 600 - Rubber Research Institute of Malaysia foram divididas em dois tratamentos, tratamento 1 = plantas irrigadas (IR) e tratamento 2 = plantas não irrigadas (NI). Nestas plantas, a fotossíntese (A) foi acompanhada durante todo o período experimental (0, 10, 25, 32, 48, 52 e 68 dias). O potencial hídrico foliar (ψw) foi determinado usando-se uma câmara de pressão do tipo Scholander, a fotossíntese (A), condutância estomática (gs) e transpiração (E) foram determinadas usando-se um analisador de gás infravermelho (LI-6400XT, LI-COR, Lincoln, Nebraska, USA) e o conteúdo de carboidratos foliares e de prolina foram determinados por espectrofotometria (Amersham Biosciences Ultrospec 3100 pro). O ψw, A, gs, E e o conteúdo de amido foliar no tratamento NI foram reduzidos durante os primeiros 32 dias, em que A atingiu valores próximos a 0 μmol m-2s-1.Porém, houve aumento da concentração de açúcar solúvel total e de prolina (tratamento NI) neste mesmo período. A recuperação da fotossíntese (NI) ocorreu após 22 dias depois da reidratação, quando comparado ao tratamento (IR).  Portanto, pode-se concluir que o clone RRIM 600 possui tolerância ao estresse hídrico em termos de como lidar com o estresse hídrico progressivo, mas a recuperação ao estresse foi relativamente lenta.

No abstract

Agro-industrial byproducts possess biotechnological potential due to the presence of bioactive compounds. These have positive metabolic effects, such as the reduction of the risk of chronic diseases, inflammation, among others. The cashew apple is one of these byproducts and stands out for its levels of phenolic compounds, flavonoids and ascorbic acid, which provide high antioxidant capacity, in addition to being an excellent source of pectin, a dietary fiber that stimulates the growth of bifidobacteria. The aim of this study was to evaluate the bioactive characteristics and the in vitro prebiotic effect of processed cashew apple when subjected to Bifidobacterium lactis. Anaerobic fermentation was carried out in a shaker at 100 rpm, 37 °C for 24 hours, using processed cashew apple as the substrate, which was enriched with a nutrient solution containing mineral salts. The growth was estimated in colony-forming units (CFU/mL), during strategic intervals of fermentation times on selective bifidobacteria agar medium, and the medium's pH was monitored. The prebiotic fructooligosaccharide (FOS) was used as a control. The cashew apple showed bioactive properties, with ascorbic acid values of 4.58 ± 0.00 mg/100 g, total phenolic compounds of 366.85 ± 3.43 mg GAE/100 g, flavonoids of 85.03 ± 4.15 mg CE/100 g and antioxidant capacity of 17.78 ± 0.20 µM TEAC/g. Plate counts showed small white colonies and complete regular edges. The growth of bifidobacteria in FOS was 10 Log CFU/mL -1 after 24 hours of fermentation, while in the cashew apple the growth was 8.8 Log CFU mL -1 after 12 hours of fermentation, with a reduction in pH medium (pH 5.08) that left it slightly more acidic than the standard (pH 5.98). Thus, it can be inferred that the cashew apple presents important functional properties, with possible benefits to human health.

Ganoderma lucidum is a medicinal mushroom widely recognized as a source of biomolecules with pharmacological properties, however, little is known about the factors that influence the synthesis of bioactive proteins by this fungus when cultivated under submerged fermentation. The objective of this work was to evaluate the production of mycelial biomass and intracellular proteases and protease inhibitors by G. lucidum cultivated under different submerged fermentation conditions. The cultivation was carried out in a medium composed of glucose (10 or 20 g.L-1), soy peptone (2.5 or 5 g.L-1) and yeast extract (5 g.L-1), with incubation under agitation (120 rpm) and non-agitation, totaling 8 experimental conditions. Biomass production was determined from the dry weight, while glucose consumption was estimated by quantification of reducing sugars. The proteins were extracted in NaCl (0.15 M), and the protein extracts were submitted to protein quantification by the Bradford method, total proteolytic activity using azocasein, caseinolytic and fibrinolytic activity in Petri dishes, activity of serine (trypsin and chymotrypsin) and cysteine (papain) protease inhibitors. Cultivation in agitated condition showed higher biomass production with a maximum value of 7 g.L-1, in addition to higher activities of trypsin, chymotrypsin and papain inhibitors, with 154 IU.mg-1, 153 IU.mg-1 e 343 IU.mg-1 of protein, respectively. The non-agitated condition showed a greater potential for obtaining proteins, total proteases, caseinolytic and fibrinolytic enzymes, with maximum values of 433 mg.g-1 of extract, 71 U.mL-1 of extract, 63.62 mm2 and 50.27 mm2, respectively. Thus, a medium composed of soy peptone, yest extract and glucose in a 1:2:4 proportion is recommended, under agitation to produce protease inhibitors, and the non-agitated condition when the target is, mainly caseinolytic and fibrinolytic enzymes.

White rot fungi have one of the most efficient oxidative lignin degradation systems, and present an enzymatic complex that is responsible for digesting lignocellulosic matter. The aim of this study was to evaluate the production of laccase and total peroxidases by Ganoderma lucidum via solid-state fermentation using açaí seeds and marupá (Simarouba amara) sawdust unsupplemented and supplemented with wheat, corn and rice bran. G. lucidum was inoculated in substrates prepared with the residues and incubated at 25 ºC. Enzymatic extractions were performed on the culture substrates every 2 days for 30 days. The enzymatic activities were determined using ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), with the addition of the enzymatic cofactor H2O2 for total peroxidases. The laccase activity was higher in the supplemented residues, with emphasis on the açaí-based substrate on the 16th day of cultivation, while in marupá the maximum activity was on the 6th day. In the unsupplemented açaí residue, the maximum peak of activity was on the 8th day and, in marupá, no fungal growth was observed. As for total peroxidases, G. lucidum cultivated in the supplemented açaí substrates showed activity peaks on the 8th, 12th, 16th and 28th day, and on 6th and 12th day under unsupplemented conditions. While, in the marupá, total peroxidase activity was observed only on the 6th day of cultivation. Thus, G. lucidum showed potential for producing laccases and total peroxidases, with the substrate supplementation inducing the synthesis of these enzymes.