Seed Coating: A Tool for Delivering Beneficial Microbes to Agricultural Crops

Plant beneficial microbes (PBMs), such as plant growth-promoting bacteria, rhizobia, arbuscular mycorrhizal fungi, and Trichoderma, can reduce the use of agrochemicals and increase plant yield, nutrition, and tolerance to biotic-abiotic stresses. Yet, large-scale applications of PBM have been hampered by the high amounts of inoculum per plant or per cultivation area needed for successful colonization and consequently the economic feasibility. Seed coating, a process that consists in covering seeds with low amounts of exogenous materials, is gaining attention as an efficient delivery system for PBM. Microbial seed coating comprises the use of a binder, in some cases a filler, mixed with inocula, and can be done using simple mixing equipment (e.g., cement mixer) or more specialized/sophisticated apparatus (e.g., fluidized bed). Binders/fillers can be used to extend microbial survival. The most reported types of seed coating are seed dressing, film coating, and pelleting. Tested in more than 50 plant species with seeds of different dimensions, forms, textures, and germination types (e.g., cereals, vegetables, fruits, pulses, and other legumes), seed coating has been studied using various species of plant growth-promoting bacteria, rhizobia, Trichoderma, and to a lesser extent mycorrhizal fungi. Most of the studies regarding PBM applied via seed coating are aimed at promoting crop growth, yield, and crop protection against pathogens. Studies have shown that coating seeds with PBM can assist crops in improving seedling establishment and germination or achieving high yields and food quality, under reduced chemical fertilization. The right combination of biological control agents applied via seed coating can be a powerful tool against a wide number of diseases and pathogens. Less frequently, studies report seed coating being used for adaptation and protection of crops under abiotic stresses. Notwithstanding the promising results, there are still challenges mainly related with the scaling up from the laboratory to the field and proper formulation, including efficient microbial combinations and coating materials that can result in extended shelf-life of both seeds and coated PBM. These limitations need to be addressed and overcome in order to allow a wider use of seed coating as a cost-effective delivery method for PBM in sustainable agricultural systems.info:eu-repo/semantics/publishedVersio

Using microbial seed coating for improving cowpea productivity under a low‐input agricultural system

BACKGROUND Plant‐growth‐promoting rhizobacteria (PGPR) and arbuscular mycorrhizal (AM) fungi have the ability to enhance the growth, fitness, and quality of various agricultural crops, including cowpea. However, field trials confirming the benefits of microbes in large‐scale applications using economically viable and efficient inoculation methods are still scarce. Microbial seed coating has a great potential for large‐scale agriculture through the application of reduced amounts of PGPR and AM fungi inocula. Thus, in this study, the impact of seed coating with PGPR, Pseudomonas libanensis TR1 and AM fungus, Rhizophagus irregularis (single or multiple isolates) on grain yield and nutrient content of cowpea under low‐input field conditions was evaluated. RESULTS Seed coating with P. libanensis + multiple isolates of R. irregularis (coatPMR) resulted in significant increases in shoot dry weight (76%), and in the number of pods and seeds per plant (52% and 56%, respectively) and grain yield (56%), when compared with non‐inoculated control plants. However, seed coating with P. libanensis + R. irregularis single‐isolate (coatPR) did not influence cowpea grain yield. Grain lipid content was significantly higher (25%) in coatPMR plants in comparison with control. Higher soil organic matter and lower pH were observed in the coatPMR treatment. CONCLUSIONS Our findings indicate that cowpea field productivity can be improved by seed coating with PGPR and multiple AM fungal isolates under low‐input agricultural systems. © 2019 Society of Chemical Industryinfo:eu-repo/semantics/publishedVersio

Seed Coating with Arbuscular Mycorrhizal Fungi for Improved Field Production of Chickpea

Although arbuscular mycorrhizal (AM) fungi are known to promote growth and yield of agricultural crops, inoculation methods for effective scaling up from greenhouse to the field are still underexplored. The application of single or mixed beneficial AM fungal isolates is hindered by the lack of experimental reproducibility of findings at different scales and the cost-effectivity of inoculation methods. Seed coating has been considered a feasible delivery system of AM fungal inocula for agricultural crops. In this study, the impact of single and multiple AM fungal isolates applied via seed coating on chickpea productivity was evaluated under greenhouse and field conditions. Overall, plants inoculated with multiple AM fungal isolates had better performance than those inoculated with single AM isolate under greenhouse and field conditions. While plants in greenhouse displayed higher shoot dry weight (14%) and seed individual weight (21%), in field, inoculation with multiple AM isolates increased pod (160%), and seed (148%) numbers, and grain yield (140%). Under field conditions, mycorrhizal root colonization was significantly higher in chickpea plants inoculated with multiple AM fungal isolates compared to other treatments. These findings highlight the potential of field-inoculation with multiple AM fungal isolates via seed coating as a sustainable agricultural practice for chickpea production.info:eu-repo/semantics/publishedVersio

How additive manufacturing can boost the bioactivity of baked functional foods

The antioxidant activity of baked foods is of utmost interest when envisioning enhancing their health benefits. Incorporating functional ingredients is challenging since their bioactivity naturally declines during baking. In this study, 3D food printing and design of experiments are employed to clarify how the antioxidant activity of cookies enriched with encapsulated polyphenols can be maximized. A synergistic effect between encapsulation, time, temperature, number of layers, and infill of the printed cookies was observed on the moisture and antioxidant activity. Four-layer cookies with 30% infill provided the highest bioactivity and phenolic content if baked for 10 min and at 180 °C. The bioacitivity and total phenolic content improved by 115% and 173%, respectively, comparing to free extract cookies.Moreover, the proper combination of the design and baking variables allowed to vary the bioactivity of cooked cookies (moisture 35%) between 300 and 700 ?molTR/gdry. The additive manufacture of foods with interconnected pores could accelerate baking and browning, or reduce thermal degradation. This represents a potential approach to enhance the functional and healthy properties of cookies or other thermal treated bioactive food products.The research leading to these results has received funding from FODIAC – Food for Diabetes and Cognition, funded by European Union, under the call Marie Skłodowsk-Curie Research and Innovation Staff Exchange (Ref. H2020-MSCA-RISE-778388); PhD grantship from Fondazione di Piacenza e Vigevano (Doctoral School on the Agro-Food System, Università Cattolica del Sacro Cuore); Fondazione Cariplo through the project ReMarcForFood – Biotechnological strategies for the conversion of Winemaking by-products and their recycling into the food chain: development of new concepts of use, 2016-0740 grant.info:eu-repo/semantics/publishedVersio

Chemical Composition, Antioxidant, Antimicrobial and Antidiabetic Potential of Philodendron Bipinnatifidum Schott ex Endl

Many of the species used in popular medicine do not have their biological activities already proven by scientific studies. Among these species, the endemic South American Philodendron bipinnatifidum Schott ex Endl deserves special attention since it is already in use in popular medicine for inflammation cases, such as erysipelas, orchitis and ulcers. This study evaluated the antioxidant, antimicrobial and antidiabetic activities of extracts of the hastes de P. bipinnatifidum. The ethanolic extract showed a significant antioxidant potential. The ethyl acetate extract resulted in high antimicrobial activity against Streptococcus pyogenes. The most significant biological activity of ethyl acetate extract relates to its chemical composition when compared with ethanolic extract, which showed the highest concentration of bioactive compounds. In vitro antidiabetic activity was only evaluated for ethyl acetate extract, resulting in inhibition of intestinal disaccharidases (maltase and sucrase) at concentration of 500 μg/mL

Probiotic edible films from bacterial cellulose/cashew tree gum

Edible films are thin layers of biopolymer-based materials, which are expected to help the packaging system in protecting food against environmental factors. Besides passive protection, edible films may also be carriers of active/bioactive components. Probiotic films are expected not only to bring health benefits to the consumers, but also to extend food microbial shelf life due to competitive effects of probiotics1. Bacterial cellulose (BC) has been presented as a promising matrix for immobilization of probiotics, protecting them against adverse factors e.g. stomach pH2. In this study, BC was combined to cashew tree gum (CG) to produce an edible film carrying a probiotic bacteria (Bacillus coagulans). CG was used to decrease the viscosity of film forming dispersions. Four films were produced: BC/CG/Pro (containing the probiotic B. coagulans), BC/CG/Pre (containing the prebiotic fructooligosaccharides FOS), BC/CG/Syn (containing both probiotic and prebiotic, making it synbiotic), and BC/CG (a control film). The presence of the probiotic and/or prebiotic affected the tensile properties of the films, especially the tensile strength. The survival rate of the probiotic on film drying and storage was increased by the presence of FOS. An in vitro digestibility test was also carried out on films, demonstrating that the bacteria in BC/CG/Pro films exhibited an enhanced survival rate on gastric environment when compared to the free probiotic.info:eu-repo/semantics/publishedVersio