Search

Main conclusion: Gibberellic acid is a plant growth hormone that promotes cell expansion and division. Studies have aimed at optimizing and reducing production costs, which could make its application economically viable for different cultivars.Gibberellins consist of a large family of plant growth hormones discovered in the 1930s, which are synthesized via the terpenes route from the geranylgeranyl diphosphate and feature a basic structure formed by an ent-gibberellane tetracyclic skeleton. Among them, only four have biological activity, including gibberellic acid (GA3), which acts as a natural plant growth regulator, especially for stem elongation, seed germination, and increased fruit size. It can be obtained from plants, fungi, and bacteria. There are also some reports about microalgae GA3 producers. Fungi, especially Gibberella fujikuroi, are preferred for GA3 production via submerged fermentation or solid-state fermentation. Many factors may affect its production, some of which are related to the control and scale-up of fermentation parameters. Different GA3 products are available on the market. They can be found in liquid or solid formulations containing only GA3 or a mixture of other biological active gibberellins, which can be applied on a wide variety of cultivars, including crops and fruits. However, the product’s cost still limits its large and continuous application. New low-cost and efficient GA3 production alternatives are surely welcome. This review deals with the latest scientific and technological advances on production, recovery, formulation, and applications of this important plant growth hormone. [ABSTRACT FROM AUTHOR]

The gibberellins (GAs) are an important group of hormones which exert various effects on promoter and regulator of plant growth. Gibberellic acid (GA3) is a natural plant hormone, with great economical and industrial importance. It affects stem elongation, germination, elimination of dormancy, flowering, sex expression, enzyme induction and leaf and fruit senescence. Despite its diverse applications, the use of GA3 is limited due to its high production costs. The industrial process currently used for the production of GA3 is based on submerged fermentation (SmF) techniques. As an alternative for its production, solid state fermentation (SSF) has also been investigated for its ability to increase the yields of GA3 with the use of agro-industrial wastes as support/substrate, which contributes to the decreased production costs. This review describes GA3's physical, chemical and biological properties, its production by fermentation and new advances that are being carried out with special interest on the SSF technique. [ABSTRACT FROM AUTHOR]