Juliana Silveira do Valle

Genome of Herbaspirillum seropedicae Strain SmR1, a Specialized Diazotrophic Endophyte of Tropical Grasses

The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme—GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.

Effects of Agaricus brasiliensis mushroom in Walker-256 tumor-bearing rats

Agaricus brasiliensis is a mushroom native to São Paulo State, Brazil, that is studied for its medicinal proprieties. This work aimed to investigate the antitumoral activity of A. brasiliensis extracts and pure powdered basidiocarp preparation using Walker-256 (W256) tumor-bearing rats, a model for cancer-related cachexia studies. The rats were treated for 14 days by gavage (136 mg/kg) and at the end of the experiment tumors were collected to calculate mass and volume. Blood was collected for determination of plasma glucose, albumin, alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Hepatic and tumor enzymes indicating oxidative stress were also evaluated. The results showed that all 4 treatments (pure powdered basidiocarp and aqueous, acid, and alkaline extracts) significantly reduced tumor size and promoted gain in body weight. Plasmatic analysis showed a reduction in AST level and increased glycemia in the treated rats. Pure basidiocarp preparations improved the liver catalase and superoxide dismutase activity, but did not change the glutathione S-transferase activity. The data collected from the W256 tumor-bearing rats revealed the beneficial effects of A. brasiliensis in tumor treatment, mainly related to cachexia. The benefits can be partly related to antioxidant activity and to reduction of weight loss and tumor growth.

Iron bioaccumulation in mycelium of Pleurotus ostreatus

Pleurotus ostreatus is able to bioaccumulate several metals in its cell structures; however, there are no reports on its capacity to bioaccumulate iron. The objective of this study was to evaluate cultivation variables to increase iron bioaccumulation in P. ostreatus mycelium. A full factorial design and a central composite design were utilized to evaluate the effect of the following variables: nitrogen and carbon sources, pH and iron concentration in the solid culture medium to produce iron bioaccumulated in mycelial biomass. The maximum production of P. ostreatus mycelial biomass was obtained with yeast extract at 2.96 g of nitrogen L −1 and glucose at 28.45 g L −1 . The most important variable to bioaccumulation was the iron concentration in the cultivation medium. Iron concentration at 175 mg L −1 or higher in the culture medium strongly inhibits the mycelial growth. The highest iron concentration in the mycelium was 3500 mg kg −1 produced with iron addition of 300 mg L −1 . The highest iron bioaccumulation in the mycelium was obtained in culture medium with 150 mg L −1 of iron. Iron bioaccumulation in P. ostreatus mycelium is a potential alternative to produce non-animal food sources of iron.

Mycelial antineoplastic activity of Agaricus blazei

Basidiocarp of Agaricus blazei (=Agaricus brasiliensis; =Agaricus subrufescens) is used as teas or capsules due to its antineoplastic effect but there are few reports of using mycelium for this purpose. The objective of this study was to evaluate the antineoplastic activity on sarcoma 180 cells implanted in mice of two forms of preparation of the mycelium from two A. blazei strains grown in culture medium with different concentrations of isolated soy protein. Mycelia were grown in Pontecorvo medium with different concentrations of isolated soybean protein (ISP). Mycelial hot water extract, moistened mycelial powder, hot water extract of green tea, Ifosfamida® (ifosfamide drug), and saline solution were administered daily by gavage in mice with sarcoma 180 cells to evaluate antineoplastic activity. It was concluded that antineoplastic activity was the same for both strains, except when used as moistened mycelial powder, which rules out the use of mycelial powder in capsules. Mycelial hot water extract had high antineoplastic activity with lower metabolic demand on the spleen and maintenance of normal blood parameters. Mycelial growth in different ISP concentrations had the same antineoplastic activity. Also the vegetative mycelium was as effective as the basidiocarp for sarcoma 180 tumor inhibition. Green tea was as effective as mycelial hot water extract.

Decolorization of remazol brilliant blue R with laccase from Lentinus crinitus grown in agro-industrial by-products

Lentinus crinitus is a white-rot fungus that produces laccase, an enzyme used for dye decolorization. Enzyme production depends on cultivation conditions, mainly agro-industrial by-products. We aimed to produce laccase from Lentinus crinitus with agro-industrial by-products for dye decolorization. Culture medium had coffee husk (CH) or citric pulp pellet (CP) and different nitrogen sources (urea, yeast extract, ammonium sulfate and sodium nitrate) at concentrations of 0, 0.7, 1.4, 2.8, 5.6 and 11.2 g/L. Enzymatic extract was used in the decolorization of remazol brilliant blue R. CH medium promoted greater laccase production than CP in all evaluated conditions. Urea provided the greatest laccase production for CH (37280 U/L) as well as for CP (34107 U/L). In CH medium, laccase activity was suppressed when carbon-to-nitrogen ratio changed from 4.5 to 1.56, but the other nitrogen concentrations did not affect laccase activity. For CP medium, reduction in carbon-to-nitrogen ratio from 6 to 1.76 increased laccase activity in 17%. The peak of laccase activity in CH medium occurred on the 11th day (41246 U/L) and in CP medium on the 12th day (32660 U/L). The maximum decolorization within 24 h was observed with CP enzymatic extract (74%) and with CH extract (76%).

Long-term cryopreservation of basidiomycetes

Basidiomycetes have several biotechnological and industrial applications such as enzyme production, bioremediation, pharmaceutical and functional food production. Due to climatic features, the preservation of several basidiomycetes is threatened, and to guarantee the preservation of this genetic resource, the development of long-term preservation techniques is necessary once there is no universal protocol for the cryopreservation of basidiomycetes. Cryopreservation is a technique in which microorganisms are submitted to ultralow temperatures. Therefore, this study aimed to collect information on the main conditions for long-term cryopreservation of basidiomycetes in the last 20 years. Scientific articles on cryopreservation of basidiomycetes published from 1997 to 2016, were researched, and only the studies on two intervals of cryopreservation were considered: from 1 to 2 years and for longer than 2 years. The analyzed conditions of basidiomycete cryopreservation were: most studied genera, cryopreservation temperature, substrate, cryoprotectant (and preservation substrate), cryopreservation period, thawing temperature and cultivation medium after thawing, physiological and genetic stability of basidiomycetes after thawing in cryopreservation. In this review, the viability of the main cryopreservation conditions of basidiomycetes studied in the last 20 years are presented and discussed.

Cryopreservation at −75 °C of Agaricus subrufescens on wheat grains with sucrose

Agaricus subrufescens is a basidiomycete which is studied because of its medicinal and gastronomic importance; however, less attention has been paid to its preservation. This study aimed to evaluate the effect of sucrose addition to substrate and cryotube on the viability of Agaricus subrufescens cryopreserved at −20 °C and at −75 °C for one and two years. Zero, 10% or 20% sucrose was added to potato dextrose agar or wheat grain. The mycelia were cryopreserved in the absence of cryoprotectant or with sucrose solutions at 15%, 30% or 45%. After one or two years at −75 °C or at −20 °C, mycelia were thawed and evaluated about viability, initial time of growth, colony diameter and genomic stability. Cryopreservation at −20 °C is not effective to keep mycelial viability of this fungus. Cryopreservation at −75 °C is effective when sucrose is used in substrates and/or cryotubes. Without sucrose, cryopreservation at −75 °C is effective only when wheat grains are used. Physiological characteristic as mycelial colony diameter is negatively affected when potato dextrose agar is used and unaffected when wheat grain is used after two-year cryopreservation at −75 °C. The fungus genome does not show alteration after two-year cryopreservation at −75 °C.

ATIVIDADE RESIDUAL E CARÊNCIA IRREGULAR DO ÁCIDO DICLOROFENOXIACÉTICO (2,4-D) NO DESENVOLVIMENTO INICIAL DA SOJA

Dichlorophenoxyacetic acid (2,4-D) is widely used in the selective, post-emergence control of narrow-leaf plants such as wheat, corn, and rice, among others. However, its uncontrolled use can cause problems in the development of the crop. The purpose of this paper was to evaluate the damage caused by the inadequate use of 2,4-D in the early development of soybean (Glycine max). The treatments consisted of a combination of five grace periods: 1, 4, 8, 12 and 15 days before sowing; and two application doses: the recommended dose and a duplicate dose (L/ha), consisting of a factorial matrix of 5x2, with three replicates. The plants were cultivated for 44 days, then collected and analyzed for germination rate (%), regrowth number, chlorophyll index, root and shoot length (cm), dry and fresh mass (g). The duplicate dose showed a greater effect on all analyzed variables, reducing the emergency percentage by 20%. The chlorophyll index decreased when compared to the shortest (1 day) and longest (15 days) grace periods, and in the duplicate dose. Dry mass was also higher when using the recommended dose, as well as the root and shoot length. Grace periods of 1, 4 and 8 days were the ones that were most influenced the root growth.