Jackfruit Leaf Protein Hydrolysates Obtained by Enzymatic Hydrolysis of Leaf Protein Concentrate with Pepsin and Pancreatin: Molecular Weight, Cytotoxicity, Antiproliferative Activity, and Oxidative Stress.

Jackfruit leaf protein hydrolysates obtained from the enzymatic hydrolysis of leaf protein concentrate with gastrointestinal enzymes have shown good techno-functional properties and high antioxidant capacity. However, molecular weight, antiproliferative activity, cytotoxicity and the ability to reduce reactive oxygen species (ROS) are still unknown. Therefore, this study aimed to evaluate the effect of jackfruit leaf protein hydrolysates obtained by enzymatic hydrolysis with pepsin and pancreatin at different hydrolysis times (30-240 min) on molecular weights, cytotoxicity, antiproliferation of cancer cells, and the reduction of reactive oxygen species in H2O2-induced HaCaT cells. The electrophoretic profile indicated that H-Pep contains peptides with molecular weights between 25 - 20 kDa. Meanwhile, H-Pan is composed of molecular weight products between 25 - 20 kDa and < 20 kDa. H-Pan and H-Pep (125-500 µg/mL) did not show significant cytotoxicity on HaCaT (human keratinocytes) and J774A.1 (murine macrophage cells). Antiproliferative activity was achieved in human cervical, ovarian, and liver cancer cells. H-Pan-240 min (1000 µg/mL) reduced the cell viability of cervical cancer cells by 23% while H-Pan-60 min significantly reduced cell viability of ovarian and liver cancer cells by 14.5 (500 µg/mL) and 17% (1000 µg/mL), respectively (P < 0.05). The protective effect against oxidative stress on H2O2-stressed HaCaT cells was obtained with H-Pep-60 min, which reduced 25% of ROS at 250 µg/mL (P < 0.05). The findings demonstrate the safe use of green biomass as a source of plant protein hydrolysates.

Improvement of the production and quality of Cordyceps javanica conidia for the control of Diaphorina citri adults.

This study aimed to evaluate the use of palm kernel meal (PKM) in the traditional solid-state fermentation system to improve the production and quality of Cordyceps javanica conidia. The impact of PKM was determined by measuring conidia yield, viability, hydrophobicity, shelf life, and conidia pathogenicity against Diaphorina citri adults. By supplementing rice grains with 5% palm kernel meal increased the conidial yield by up to 40%, without compromising conidia viability and hydrophobicity. In addition, conidia caused higher levels of mortality by mycosis against D. citri adults (90%), relative to conidia harvested from rice (52%). The conidia recovered from rice/palm kernel meal mixtures also retained viability greater than 90% after storage for 10 months at 4 °C, while the conidia produced on rice reached 80%. Thus, conidia produced in the presence of palm kernel meal can be consumed immediately or in the medium term. Some process advantages of the palm kernel meal as co-substrate in the traditional production system of C. javanica are also mentioned. These results are attractive for improving the mycoinsecticide production process, with excellent cost-benefit and minimal changes in infrastructure and process.

Principal component analysis of the biological characteristics of entomopathogenic fungi in nutrient-limited and cuticle-based media.

Media formulated with insect cuticle (0.5% and 1%; Sphequit Sph®), with a reduction in nutrients (» Sabouraud dextrose agar + yeast [SDAY]) and commercial media (potato dextrose agar, Sabouraud dextrose agar) were evaluated for the cultivation of Beauveria bassiana, Cordyceps javanica (Isaria javanica [Bally] Samson & Hywel-Jones), and Metarhizium robertsii. By using principal component analysis, it was determined that the » SDAY and Sph formulations have greater advantages than commercial media for the development of fungi. The » SDAY and Sph (0.5% and 1%) improved hydrophobicity, radial growth rate, germination, conidia yield, and virulence in B. bassiana; in M. robertsii, they favored conidia yield, germination, and virulence, and in C. javanica, the » SDAY and Sph 0.5% media enhanced conidia yield, germination, radial growth rate, and virulence. We suggest that these formulations are an alternative to commercial culture media as they are cheaper and appropriate to improve the growth characteristics and virulence of the three strains evaluated. Some applications of culture media are suggested, and the importance of multivariate analysis as an exploratory tool to carry out the choice of culture media in a suitable way for the development of mycoinsecticides is also discussed.

Morphological and enzymatic response of the thermotolerant fungus Fomes sp. EUM1 in solid state fermentation under thermal stress.

Thermotolerance of the fungus Fomes sp. EUM1 was evaluated in solid state fermentation (SSF). This thermotolerant strain improved both hyphal invasiveness (38%) and length (17%) in adverse thermal conditions exceeding 30°C and to a maximum of 40°C. In contrast, hyphal branching decreased by 46% at 45°C. The production of cellulases over corn stover increased 1.6-fold in 30°C culture conditions, xylanases increased 2.8-fold at 40°C, while laccase production improved 2.7-fold at 35°C. Maximum production of lignocellulolytic enzymes was obtained at elevated temperatures in shorter fermentation times (8-6 days), although the proteases appeared as a thermal stress response associated with a drop in lignocellulolytic activities. Novel and multiple isoenzymes of xylanase (four bands) and cellulase (six bands) were secreted in the range of 20-150 kDa during growth in adverse temperature conditions. However, only a single laccase isoenzyme (46 kDa) was detected. This is the first report describing the advantages of a thermotolerant white-rot fungus in SSF. These results have important implications for large-scale SSF, where effects of metabolic heat are detrimental to growth and enzyme production, which are severely affected by the formation of high temperature gradients.