Advances in plant growth-promoting bacterial inoculant technology: formulations and practical perspectives (1998–2013)

Abstract

Background Inoculation of plants to enhance yield of crops and performance of other plants is a century old, proven technology for rhizobia and a newer venue for plant growth-promoting bacteria and other plant symbionts. The two main aspects dominating the success of inoculation are the effectiveness of the bacterial isolate and the proper application technology. Scope An assessment of practical aspects of bacterial inoculants for contemporary agriculture and environmental restoration is critically evaluated from the point of view of their current technological status, current applications, and future use. This is done because there are windows of opportunity for new developments in applied research using renewable, non-contaminated natural resources and new venues for research. Special emphasis is given to formulations and polymeric carriers. This review concentrates on practical aspect of inoculation technology dating from 1998 to 2013. Earlier publications are mentioned only for clarification of a specific point. Conclusions This review discusses characteristics of a carrier for inoculants, formulations of inoculants including liquid, organic, inorganic, polymeric, and encapsulated formulations. Technical aspects include inoculation techniques (soil and seed application), mass culture production, bulk sterilization, seed coating, shelf-life, and effect of moisture. Future research venues needed are noted.

Development and field evaluation of liquid inoculants with native <i>Bradyrhizobial</i> strains for peanut production

“…For production of Bradyrhizobium inoculant, a low-cost medium is preferable. Currently available culture media use yeast extract and manitol as essential components (Balatti, 1992;Bashan et al, 2013). In this study, the greatest number of viable cells and growth rate for all strains were reached in the balanced medium (Table 3; Fig.…”

“…The development of improved culture media and carrier material for enhancing survival of rhizobial inoculants is important for ensuring the maintenance of inoculant quality during storage and transport to the field (Bashan et al, 2013). For production of Bradyrhizobium inoculant, a low-cost medium is preferable.…”

Agricultural uses of plant biostimulants

“…Microbial inoculants mainly include free-living bacteria, fungi, and arbuscular mycorrhizal fungi (AMF) (Berg 2009;Dodd and Ruiz-Lozano 2012;Vessey 2003) that were isolated from a variety of environments including soil, plants, plant residues, water, and composted manures. Among the biofertilizers that have been studied in depth are plant growth-promoting rhizobacteria (PGPR) (Kloepper et al 1989) and plant growth-promoting bacteria (PGPB), both of which are free-living bacteria mainly isolated from the rhizosphere (Bashan et al 2014). Several reviews of PGPR have been published in the past few years (Antoun and Kloepper 2001;Bhattacharyya and Jha 2012;Spaepen et al 2009).…”

Processing, Valorization and Application of Bio-Waste Derived Compounds from Potato, Tomato, Olive and Cereals: A Review

“…A step forward in formulation of fertilizers is the addition of plant-growth promoting bacteria which function as bio-inoculants in tomato residues based compost and are efficient as well as environmental-friendly alternatives to chemical compounds [200]. These have been applied to promote crop production by different bio-fertilization mechanisms, such as biological nitrogen fixation, production of phytohormones, solubilization of insoluble minerals and biocontrol processes that include phytopathogen antagonism and plant-induced resistance [201][202][203][204].…”