Hydrolysis of pineapple crown biomass by cellulolytic enzymes produced by Fusarium oxysporum

The development of microbial enzymes is of great importance in biochemical process industries. Among the enzymes of industrial importance, cellulolytic and xylanolytic enzymes stand out, which are responsible for the degradation of lignocellulosic material that is usually discarded by the agro-industrial sector. In order to produce the enzymes CMCase, β-glycosidase, xylanase and β-xylosidase, the fungus Fusarium oxysporum was used in liquid fermentation using pre-treated pineapple crown biomass as a carbon source. In order to optimize the production of these enzymes, cultures were carried out for 168 hours, 30 °C at 180 rpm. The biomass underwent a pre-treatment in two stages, the first being submitted to 121 °C for 7 min, while the second was added diluted sulfuric acid to 1%, in the proportion of 1:5 (m/v), at 121 °C for 27 minutes. The partial characterization of the crude extract showed a temperature of 50 ºC as the most satisfactory for the action of these enzymes, and the ideal pH range ranged from 3.5 to 5.5. The enzymatic hydrolysis of pineapple crown, with and without pretreatment, was performed using lyophilized crude extract (CMCase = 9.78 U/mL, β-glucosidase = 10.86 U/mL, xylanase = 27.90 U/mL and β-xylosidase = 0.018 U/ml). An experimental design of the Central Composite Rotational Design was carried out. It was possible to evaluate the effect and influence of pH, biomass concentration and incubation time on the release of glucose in the medium (R2>0.85); pH and biomass (%) had a significant effect on glucose release.

Dynamics of aerial and perennial biomass of two lucerne cultivars with different fall dormancy subject to two severities of cutting during the establishment phase

The aim of this study was to quantify the impact of two cutting severities on the dynamics of aerial and perennial (root plus crown) biomass of lucerne (Medicago sativa L.) plants of two cultivars of contrasting fall dormancy rating during the establishment phase. We worked at Unidad Integrada Balcarce with two cultivars of lucerne (non-winter dormant: FD10; semi-winter dormant: FD6) and two cutting severities (40 and 100 mm) defining four treatments (FD6-40 mm, FD6-100 mm, FD10-40 mm and FD10-100 mm) under a completely randomized design. In both cultivars, increasing cutting severity produced a reduction in leaf area and number of nodes in the residual, resulting in a reduced production of aerial biomass during regrowth, given a reduction on shoot number. On the other hand, the effect of increased cutting severity on perennial biomass was only observed in plants of FD10 cultivar. This cultivar showed less perennial biomass when cut at 40 mm than at 100 mm, while no differences were observed between cutting heights in FD6 cultivar.

Are There Differences in the Reaction of the Light-Tolerant Subgenus Pinus spp. Biomass to Climate Change as Compared to Light-Intolerant Genus Picea spp.?

Currently, the problem of the impact of climate change on the productivity of forest ecosystems and their carbon-depositing capacity is far from being solved. Therefore, this paper presents the models for the stand biomass of the two-needled subgenus’ (Pinus spp.) and the genus Picea spp.’s trends along the trans-Eurasian hydrothermal gradients, designed for pure stands in a number of 2110- and 870-sample plots with Pinus and Picea correspondingly. It was found that in the case of an increase in mean winter temperatures by 1 °C, pine and spruce respond by increasing the biomass of most components, and in the case of an increase in the annual sum of precipitation by 100 mm, the total, aboveground, stem and root biomasses of pine and spruce react the same way, but crown biomass reacts in the opposite way. Therefore, all identified trends are species-specific.

Post-harvest quality of ‘Vitória’ pineapple as a function of the types of shoots and age of the plant for floral induction

For the production and quality of pineapple fruits, the appropriate choice of the type of propagule to be used combined with the management of the ages for floral induction are important factors to reach the maximum of desirable characteristics that will define the success in the production of the pineapple and its good acceptance in the market. The objective of this research was to evaluate the post-harvest quality of fruits developed from different types of shoots and ages of floral induction of ‘Vitória’ pineapple. The experiment was carried out in a complete randomized block design with four replications. The plots were made up of the shoots (slip and sucker) and the subplots were composed of the different ages of floral induction (8, 10 and 12 months after planting and natural flowering). Evaluations of biomass characteristics of fruits with and without crown, circumference, length, diameter, firmness, translucency, pulp color and physicochemical quality were performed. No significant interaction was observed for the biometric and biomass variables, and the type of shoots influenced only the crown biomass and the central cylinder diameter, which were higher in the slips. In addition, for the attributes color, translucent area and firmness, no interaction was found, and they were influenced only by the induction times, except for the variable color referring to the intensity of green and red colors. Regardless of the types of the shootss evaluated in the environmental conditions of planting carried out in April 2015, the fruits originated from natural inductions and inductions at 12 months presented greater firmness, a desirable characteristic for export and industrialization, mainly for the processing of slices of pineapple, pieces in syrup and crystallized. The slips natural induced and induced at 12 months provided fruits with a greater ratio between soluble solids and acidity.