Perspectives on the Use of Biopolymeric Matrices as Carriers for Plant-Growth Promoting Bacteria in Agricultural Systems

A novel biopolymer technique for encapsulation of Bacillus velezensis BV9 into double coating biopolymer made by in alginate and natural gums to biocontrol of wheat take-all disease

Bacillus velezensis has been known for its high potential in controlling agricultural diseases. Technological advances have opened new perspectives for producing effective formulations by reducing some of the obstacles to their use, such as instability and loss of activity due to exposure to adverse environmental conditions. Encapsulation is one of the new approaches in agricultural science. This research describes discoveries related to processes for the microencapsulation of B. velezensis with natural gums. The efficiency, survival, and controlled release of B. velesensis BV9 encapsulated with alginate mixed with zedo gum, mastic gum, and tragacanth gum were evaluated for this aim. Furthermore, under greenhouse conditions, the encapsulated cells were assessed to control Gaeumannomyces graminis var. tritici in wheat. The results indicated that all tested microcapsules protected >60 % of the bacterial cells. The Alginate-Zedo Gum (Alg-ZG) microcapsules showed a better-controlled release over two months. The greenhouse study indicated that treating wheat plants with Alg-ZG microcapsules was the most efficient treatment, suppressing 100 % of the pathogen. The results indicated that Alg-ZG is the most promising mixture to improve the survivability of B. velezensis BV9. Also, using natural gums and great potential of this formulation provides an effective and affordable fertilizers for agriculture.

Composition and Dynamics of Plant- and Soil-Associated Microbial Communities in Forest and Agricultural Ecosystems

Peter Kropotkin (1842-1921) is well known as an anarchist intellectual, an amiable mass of contradictions who loved humanity and was highly regarded in academic and intellectual circles, yet also penned "fiery peans to violence" in Le Révolté, the anarchist journal he established with Elisée Reclus in the 1870s [...].

Microalgal and Nitrogen-Fixing Bacterial Consortia: From Interaction to Biotechnological Potential

Microalgae are used in various biotechnological processes, such as biofuel production due to their high biomass yields, agriculture as biofertilizers, production of high-value-added products, decontamination of wastewater, or as biological models for carbon sequestration. The number of these biotechnological applications is increasing, and as such, any advances that contribute to reducing costs and increasing economic profitability can have a significant impact. Nitrogen fixing organisms, often called diazotroph, also have great biotechnological potential, mainly in agriculture as an alternative to chemical fertilizers. Microbial consortia typically perform more complex tasks than monocultures and can execute functions that are challenging or even impossible for individual strains or species. Interestingly, microalgae and diazotrophic organisms are capable to embrace different types of symbiotic associations. Certain corals and lichens exhibit this symbiotic relationship in nature, which enhances their fitness. However, this relationship can also be artificially created in laboratory conditions with the objective of enhancing some of the biotechnological processes that each organism carries out independently. As a result, the utilization of microalgae and diazotrophic organisms in consortia is garnering significant interest as a potential alternative for reducing production costs and increasing yields of microalgae biomass, as well as for producing derived products and serving biotechnological purposes. This review makes an effort to examine the associations of microalgae and diazotrophic organisms, with the aim of highlighting the potential of these associations in improving various biotechnological processes.

Biostimulant and Elicitor Responses to Cricket Frass (Acheta domesticus) in Tomato (Solanum lycopersicum L.) under Protected Conditions

Agriculture in the current century is seeking sustainable tools in order to generate plant production systems with minimal negative environmental impact. In recent years it has been shown that the use of insect frass is an option to be used for this purpose. The present work studied the effect of low doses (0.1, 0.5, and 1.0% w/w) of cricket frass (Acheta domesticus) in the substrate during the cultivation of tomatos under greenhouse conditions. Plant performance and antioxidant enzymatic activities were measured in the study as explicative variables related to plant stress responses in order to determine possible biostimulant or elicitor effects of cricket frass treatments during tomato cultivation under greenhouse conditions. The main findings of this study indicated that tomato plants responded in a dose dependent manner to cricket frass treatments, recalling the hormesis phenomenon. On the one hand, a 0.1% (w/w) cricket frass treatment showed typical biostimulant features, while on the other hand, 0.5 and 1.0% treatments displayed elicitor effects in tomato plants under evaluated conditions in the present study. These results support the possibility that low doses of cricket frass might be used in tomato cultivation (and perhaps in other crops) for biostimulant/elicitor input into sustainable production systems.