Antitumour activities of levans produced by Zymomonas mobilis strains

Levans produced by four Zymomonas mobilis strains showed antitumour activity against sarcoma 180 and Ehrlich carcinoma in Swiss albino mice. Levans from two strains (ZAP and CP4) had the highest effects. NMR analysis showed that the polymers were composed only of fructose units. The results suggested that the antineoplasic effect is associated to the polysaccharide molecular weight and that a particular molecular weight range may be responsible for this effect.     

Microhabitat Variation Explains Local‐scale Distribution of Terrestrial Amazonian Lizards in Rondônia,Western Brazil

We investigate the role of ecology and phylogeny in the association between lizard abundance and microhabitat variables in an Amazon rain forest site. Using pitfall trap arrays, we collected data from 349 individuals belonging to 23 lizard species. After accounting for spatial autocorrelation and using a canonical correspondence analysis (CCA), we found that lizard captures were significantly associated with microhabitat variables, which accounted for 48 percent of the observed variation. Furthermore, a canonical phylogenetic ordination (CPO) indicated that microhabitat variables are more important in determining the distribution of lizard species than phylogenetic relationships among species. Termite nests, canopy openness, and tree circumference were strongly associated with the number of captures of certain lizard species. Our results confirm autecology studies of individual lizard species for which data are available. We suggest that maintaining heterogeneous forested microhabitats should be a central goal for sustaining a high lizard biodiversity in Amazon rain forests.     

Elucidating the role of oxidative stress in the therapeutic effect of rutin on experimental acute pancreatitis

Introduction: Acute pancreatitis (AP) may be severe and cause hospitalization or death, and the available treatment is insufficient to control pancreatic inflammation and pain. Rutin is a natural flavonoid with the potential to treat AP via anti-inflammatory, antinociceptive, and antioxidant activities.

Aim: This study investigated the beneficial effects of rutin on experimental AP induced by l-arginine administration in mice.

Methods: The l-arginine-induced AP model was used in Swiss mice (n?=?6–8). Mice submitted to AP induction were treated with rutin (37.5, 75, or 150?mg kg^?1, p.o.) or vehicle (saline) after 24, 36, 48, and 60?h of AP induction. Abdominal hyperalgesia, serum enzymes, interleukin (IL)-6 levels, pancreatic inflammatory parameters, malondialdehyde (MDA) levels, antioxidant enzyme activities, and 3-nitrotyrosine contents were measured 72?h after induction.

Results: Mice submitted to l-arginine injections developed abdominal hyperalgesia and increased serum amylase, lipase, C-reactive protein and IL-6 concentrations; and increased pancreatic myeloperoxidase activity, edema index, MDA, and 3-nitrotyrosine contents. A marked decrease in catalase activity was observed in the pancreas without alterations of superoxide dismutase (SOD) activity compared with the control group. Rutin treatment significantly impaired all the parameters that were altered by AP induction, but increased catalase and SOD activities in the pancreas compared with the vehicle-treated group.

Conclusion: Rutin treatment exerted a protective effect on l-arginine-induced AP by mechanisms involving the reduction of oxidative stress, which suggests that this flavonoid has a potential for future approaches designed for the management of AP.     

Bioavailability of heavy metals in sediments of two coastal lagoons in Rio de Janeiro,Brazil

The distribution and bioavailability of trace metals in two contrasting tropical coastal lagoons were studied. The concentration of trace metals in aquatic macrophytes was compared with those found in sediments under weakly and strongly bound forms. The results showed that total metal concentrations in sediments did not explain the concentration found in plants. The highest concentrations in macrophytes were observed in the lagoon which had a higher fraction of metals weakly bound to sediments, but presented the lower total metal content. Low redox potential was the major variable keeping metals in non-bioavailable forms, possibly as refractory sulfides and metal-organic complexes. Among the macrophytes, rooted species showed lower concentrations of metals as compared to algae.     

On the effect of temperature and pH on the settling behaviour of a flocculent strain ofZymomonas mobilis

Summary In this paper the effect of temperature and pH on the settling behaviour of a flocculent strain ofZymomonas mobilis is studied by using the old fashioned batch settling technique. Plots are given to show the influence of the above mentioned parameters on the settling curve behaviour.     

Microhabitat use by Rhipidomys mastacalis and Marmosops incanus (Mammalia) in a restinga areas in north‐eastern Brazil

Differences in the patterns of microhabitat use by small mammals have been largely related to the coexistence process of the species. The present study analyses how the marsupial Marmosops incanus and the rodent Rhipidomys mastacalis use the microhabitat in a areas of arboreal restinga in the Brazilian north‐east. Through capture‐marking‐recapture, sampling was performed monthly from September 2017 to August 2018 using Sherman traps and pitfall. Six microhabitat variables were measured at all capture stations. The use of vertical strata (ground and understory) was compared using a chi‐square test, and associations of species abundances with microhabitat characteristics were explored using redundancy analysis. The results indicate that the species use the vertical strata at different frequencies, with R. mastacalis found exclusively in the understory and M. incanus found more in the understory than in the ground. The variation in the abundance of the species was associated with the density of the understory, with an increase in M. incanus abundance and a decrease in R. mastacalis. Differences in the patterns found for these species in other environments indicate plasticity in relation to the use of vertical strata and the approaches used suggest that the differential use of the arboreal stratum can be a facilitator in the process of coexistence in areas of restinga. Abstract in Portuguese is available with online material.     

Tuberculosis patients co-infected with Mycobacterium bovis and Mycobacterium tuberculosis in an urban area of Brazil

In this cross-sectional study, mycobacteria specimens from 189 tuberculosis (TB) patients living in an urban area in Brazil were characterised from 2008-2010 using phenotypic and molecular speciation methods (pncA gene and oxyR pseudogene analysis). Of these samples, 174 isolates simultaneously grew on Löwenstein-Jensen (LJ) and Stonebrink (SB)-containing media and presented phenotypic and molecular profiles of Mycobacterium tuberculosis, whereas 12 had molecular profiles of M. tuberculosis based on the DNA analysis of formalin-fixed paraffin wax-embedded tissue samples (paraffin blocks). One patient produced two sputum isolates, the first of which simultaneously grew on LJ and SB media and presented phenotypic and molecular profiles of M. tuberculosis, and the second of which only grew on SB media and presented phenotypic profiles of Mycobacterium bovis. One patient provided a bronchial lavage isolate, which simultaneously grew on LJ and SB media and presented phenotypic and molecular profiles of M. tuberculosis, but had molecular profiles of M. bovis from paraffin block DNA analysis, and one sample had molecular profiles of M. tuberculosis and M. bovis identified from two distinct paraffin blocks. Moreover, we found a low prevalence (1.6%) of M. bovis among these isolates, which suggests that local health service procedures likely underestimate its real frequency and that it deserves more attention from public health officials.     

Reproductive cycle of seabob shrimp Xiphopenaeus kroyeri (Crustacea,Penaeidea) from the northeast coast of Brazil

The reproductive cycle of Xiphopenaeus kroyeri north-eastern Brazil was described to contribute to the sustainable management of this stock in the region. Specimens were collected monthly from August 2011 to July 2012 using a local vessel of the artisanal fleet. A total of 1201 individuals were analyzed (673 females and 528 males) with a mean carapace length (CL) of 1.88 ± 0.16 cm and total length (TL) of 9.00 ± 1.22 cm. The lowest CL and TL of mature females were 1.33 and 6.5 cm, respectively, and all females above 2.44 cm (CL) and 11.5 cm (TL) were mature. Ovarian maturation was classified into four stages: I (immature), II (maturing), III (mature) and IV (spawned). Individuals of all maturational stages were present throughout the year. Considering the macro and microscopic analysis, it was suggested that this species in north-eastern Brazil has a continuous reproductive cycle, with two seasonal peaks, November/December and February (austral spring and summer). A positive correlation between the percentage of mature females and temperature was observed, and a higher percentage was reported in the warmer months of the year. This suggests that the reproductive peaks can be triggered by water temperature variation throughout the year.     

From open areas to forests? The evolutionary history of Philodendron subgenus Meconostigma (Araceae) using morphological data

Due to its wide distribution covering three of the largest Neotropical biomes, Philodendron subgenus Meconostigma is an interesting model to discuss the diversification of Neotropical plants. The aim of this study was to test a previous hypothesis that the Eastern and Southern species of P. subg. Meconostigma have plesiomorphic gynoecial structure while in Amazonian species they are apomorphic. To this end, we conducted an analysis of maximum parsimony with generalized frequency coding method using a matrix with 59 morphological characters and 90% of the species of P. subg. Meconostigma. The phylogenetic reconstruction suggests that the subgenus is monophyletic and originates from open areas of Cerrado. Four morphological synapomorphies support the monophyly of the subgenus and seven synapomorphies support four minor clades within it. Our results also include characterization of three new gynoecial subtypes (A1, A2 and A3) within the subgenus. Subtype A2 (undeveloped stylar body with long stylar canals, absent central stylar dome, shallow compitum) is basal and represents the ancestral gynoecium in the group. These findings suggest that the balance between pollen uptake and accessibility of the locules were decisive to drive gynoecium evolution in the subgenus Meconostigma.     

Microwave-assisted hydrolysis of Zymomonas mobilis levan envisaging oligofructan production

Levan, a polysaccharide from Zymomonas mobilis, was hydrolyzed to obtain oligofructans or fructooligosaccharides with a degree of polymerization varying from 4 to 14. Fructooligosaccharides (FOS) are short chain fructans that beneficially affects the host by selective stimulation of growth and activity of one or a number of bacteria including probiotic bacteria in the colon. The hydrolysis was performed in a microwave oven to shorten the reaction time. The experiments showed that it is possible to maximize selected oligomers by interrupting the hydrolysis at the due time. The results allow one to infer that the procedure may also be useful for production of oligomers from other polysaccharides.