GA3 Production Research Articles

INVESTIGATION OF THE GIBBERELLIC ACID OPTIMIZATION WITH A STATISTICAL TOOL FROM Penicillium variable IN BATCH REACTOR

The culture conditions for gibberellic acid (GA3) production by the fungus Penicillium variable (P. variable) was optimized using a statistical tool, response surface methodology (RSM). Interactions of culture conditions and optimization of the system were studied using Box–Behnken design (BBD) with three levels of three variables in a batch flask reactor. Experimentation showed that the model developed based on RSM and BBD had predicted GA3 production with R 2 = 0.987. The predicted GA3 production was optimum (31.57 mg GA3/kg substrate) when the culture conditions were at 7 days of incubation period, 21% v/w of inoculum size, and 2% v/w of olive oil concentration as a natural precursor. The results indicated that RSM and BBD methods were effective for optimizing the culture conditions of GA3 production by P. variable mycelia.

New perspectives of gibberellic acid production: a review

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.

Solid-state fermentation for production of gibberellic acid using agricultural residues

Solid-State Fermentation (SSF) was employed using agricultural residues, viz. pigeon pea pod (Cajanus cajan), corncobs (Zea mays), sorghum straw (Sorghum vulgare) and pea pod (Pisum sativum) for the production of gibberellic acid (GA3) using Fusarium proliferatum NCIM1105. Studies revealed that these agricultural residues have supported excellent growth of the fungi in modified medium and gave significant yield of the GA3 with 50?60% purity using solvent-buffer-solvent extraction process. In the present work, a nutrient medium was developed and was used to enrich the solid substrate and inoculum preparation. The agricultural residue of pigeon pea pod was found most suitable substrate (6.4?7.8 mg GA3/g) followed by pea pods (5.7?6.4 mg GA3/g), corncobs (5.2?6.1 mg GA3/g) and sorghum straw (4.1?5.5 mg GA3/g) for production of GA3 measured over HPLC. In SSF, parameters such as initial moisture content, particle size, temperature and nutrient medium concentration were controlled for optimum yield of GA3 in pigeon pea pod residue.

A new alternative to produce gibberellic acid by solid state fermentation

Gibberellic acid (GA3) is an important hormone, which controls plant's growth and development. Solid State Fermentation (SSF) allows the use of agro-industrial residues reducing the production costs. The screening of strains (four of Gibberella fujikuoroi and one of Fusarium moniliforme) and substrates (citric pulp, soy bran, sugarcane bagasse, soy husk, cassava bagasse and coffee husk) and inoculum preparation study were conducted in order to evaluate the best conditions to produce GA3 by SSF. Fermentation assays were carried out in erlenmeyers flasks at 29°C, with initial moisture of 75-80%. Different medium for inoculum production were tested in relation to cells viability and GA3 production by SSF. F. moniliforme LPB 03 and citric pulp were chosen for GA3 production. The best medium for inoculum production was citric pulp extract supplemented with sucrose. GA3 production by SSF reached 5.9 g /kg of dry CP after 3 days of fermentation.

Secondary metabolite profiles and mating populations of Fusariumspecies in section Liseola associated with bakanae disease of rice

A total of 25 strains of Fusarium species that belong to F. fujikuroi (a pathogen of bakanae disease), F. proliferatum, F.sacchari, F. subglutinans and F. verticillioides were isolated from rice plants showing typical bakanae symptoms in Malaysia and Indonesia and screened for their secondary metabolites. The objectives of the studies were to determine the physiological variability based on production of moniliformin (MON), fumonisin (FB1), gibberellic acid (GA3) and fusaric acid(FA) as well as to ascertain the mating populations (MPs) within the Gibberella fujikuroi species complex based on their ability to produce perithecia and viable ascospores. Production of GA3 could be used to separate F. fujikuroi that belongs to MP-C from other species. In crosses with seven standard testers of MPs, 76% of strains could be assigned to at least one of the G. fujikuroi species complex namely MP-A (G.moniliformis), MP-B (G. sacchari), MP-C (G. fujikuroi) and MP-D (G.intermedia). Single strain (M3237P) that was assigned as MP-C, and has also been identified morphologically as F. fujikuroi was also crossed-fertile with MP-D tester. The secondary metabolites profiles and the presence of MP-A, MP-B, MP-C and MP-D strains on samples of bakanae-infected rice plants are new records in Malaysia.

Gibberellic acid production by solid-state fermentation in coffee husk.

Five strains of Gibberella fujikuroi and one of Fusarium moniliforme were screened for the production of gibberellic acid (GA3) in coffee husk, and based on the results, one strain, G. fujikuroi LPB-06, was selected. The comparative production of GA3 by solid-state fermentation and submerged fermentation indicated better productivity with the former technique, mainly with pretreated substrate. The GA3 accumulation was 6.1 times higher in the case of solid-state fermentation. Considering the C:N relation, higher yields of GA3 were achieved using a mixed substrate comprising coffee husk and cassava bagasse (7:3, dry wt), increasing the results twice. Supplementation of an optimized saline solution containing 0.03% FeSO4 and 0.01% (NH4)2SO4 enhanced the accumulation of GA3 1.7 times in the fermented substrate. Under the finally optimized condition, the culture gave a maximum of 492.5 mg of GA3/kg of dry substrate, with a pH of 5.3, moisture of 75%, and incubation temperature of 29 degrees C. GA3 yield was almost 13 times more than the initial results.

Capture of volatile metabolites for tracking the evolution of gibberellic acid in a solid-state culture of Gibberella fujikuroi

The evolution of volatile compounds produced during solid substrate cultivation (SSC) of Gibberella fujikuroi on wheat bran was tracked looking for volatile metabolites related with GA3 production. Ethyl acetate and isoamyl acetate gave identical profiles and sharp increases that abated as the production of GA3 began, while ent-kaurene displayed a profile matching that of the development of GA3. ent-Kaurene is a precursor in the synthesis of gibberellins and was the most abundant compound found.

Vegetative compatibility, biosynthesis of GA3 and virulence of Fusarium moniliforme isolates from bakanae disease of rice

Twenty‐eight isolates of Fusarium moniliforme were established from bakanae‐infected rice plants of a range of cultivars collected from various localities in Haryana, India. They were characterized by vegetative compatibility, virulence pattern on five paddy cultivars, and biosynthesis of gibberellins and were assigned to 10 vegetative compatibility groups (VCGs). Isolates from different VCGs and also within the same VCG varied considerably in virulence and GA3 production. The 28 isolates were categorized into five gibberellic acid production groups (GPG‐I–GPG‐V) and five virulence groups (VG‐I–VG‐V). Vegetative compatibility was independent of pathogenicity and of ability to produce GA3. However, GA3 production was positively correlated (r = 0.731) with pathogenic behaviour.

Attempts to overcome postfertilization barrier in interspecific crosses of the genus Lens

AbstractWild relatives are a potential source of genetic diversity to lentil (Lens culinaris Medik). The objective of this research was to obtain viable interspecific hybrids between the domesticated lentil and its wild relatives.The paper details the results of a number of interspecific crosses among L. culinaris, L. orientalis, L. odemensis, L. ervoides and L. nigricans. Viable hybrids were produced between L. culinaris × L. orientalis, L. culinaris × L. nigricans, L. culinaris × L. ervoides and between L. culinaris × L. odemensis. Further viable hybrids were obtained between L. culinaris and L. ervoides, which have the potential to be a ‘bridge’ in hybridization to L. culinaris for specific L. nicrigans lines which proved recalcitrant in L. culinaris × L. nigricans crosses. This is the first time that four wild species of lentils have been used successfully in hybridization with cultivated lentils, and viable hybrids produced. This paper also suggests that the artificial supplement of GA3, hormone is needed after fertilization for the normal growth of the hybrid embryo, possibly as the natural GA3 production is restricted with alien pollinations in cultivated lentils in both F1 and backcross hybrids.

Interactions affecting gibberellic acid production in solid-state culture: A factorial study

Abstract The production of GA3 in solid-state culture was studied using systems composed of maize cob particles soaked in an amylaceous effluent, as a function of three variables-particle diameter, volume of liquid phase, and substrate concentration—with a determinant influence on the response. The empirical model obtained provides an explanation of the behavior of the system in terms of a series of interactions with underlying problems of water activity and mass transfer, that can, however, be manipulated in a simple and reproducible manner. This model also allows the suitable orientation of production improvement, the interpretation of the mechanism of substrate inhibition detected, as well as means of correcting it without reducing the initial concentration of the substrate, and leads to an 11-fold increase in the production obtained in the preliminary assays.

A fed-batch culture model for improved production of gibberellic acid from a waste medium

The kinetics of the production of gibberellic acid (GA3) in conventional batch culture was compared with that obtained in fed-batch cultures at three different feeding regimes with media containing protein N, one of which was calculated to maintain a constant biomass, and two others able to promote linear growth. It was found that the production of GA3 improves substantially in the latter two cases, and that the general model applicable to the formation of a secondary metabolite correctly predicts the results if one dispenses with the assumption of avoiding the increase in the biomass during the production phase.

Genetics of Apical Dominance in Plantain (Musa spp., AAB Group) and Improvement of Suckering Behavior

Apical dominance, i.e., the inhibition of lateral bud growth due to growth substances released by the terminal bud, has been considered as a limiting factor for the perennial productivity of plantains (Musa spp., AAB group). Segregation ratios in F1 and F2 plantain-banana hybrids suggest that inheritance of apical dominance is controlled by a major recessive gene, ad. The dominant Ad allele improved the suckering of plantain-banana hybrids, as measured by the height of the tallest sucker at flowering and harvest. At harvest, the ratoon crop of the diploid and tetraploid hybrids had completed 70% to 100% of its vegetative development, whereas the ratoon of the plantain parents, due to high apical dominance, was only at 50% of total pseudostem growth. Sucker growth rates are generally the result of gibberellic acid (GA3) levels, and it is suggested that the Ad gene regulates GA3 production. However, the Ad gene has incomplete penetrance, genetic specificity, and variable expressivity. Increased frequency of the Ad gene and a commensurate improvement in the suckering behavior of the diploid populations may be achieved by phenotypic recurrent selection.

Factors affecting gibberellic acid production by Fusarium moniliforme in solid-state cultivation on starch

The production of gibberellic acid (GA3) by Fusarium moniliforme M-7121 in solid-state culture was evaluated in flask cultures as well as in 3-I horizontal rotary reactors. The highest production rate of GA3 was with 80% (w/v) maize flour mixed with wheat bran. The optimum initial moisture content was inversely dependent on the ambient relative humidity. The initial water activity range for optimal growth and GA3 accumulation was about 0.98 to 0.99, which is unusually high for a filamentous fungus. A low O2 concentration resulted in a much decreased GA3 yield and the appearance of a yellow to reddish pigmentation in the mycelium. The lag phase was short and rapid growth continued for up to 2 days in the rotary reactor, with a maximum specific growth rate of 0.12 h(-1). The maximum rate of GA3 production occurred during the subsequent 3 to 10 days of incubation and the final GA3 concentration reached was 18.7 mg to 19.3 mg/g dry culture. The point of maximum GA3 accumulation after 10 to 12 days of incubation was usually marked by a sharp increase in pH.

Activity of mutagens in the fungus Gibberella fujikuroi

AbstractThe efficacy of a number of mutagens was examined for Gibberella fujikuroi. Nitrosoguanidine (MNNG) was the most effective mutagen inducing mainly morphological and pigment mutants. X‐ray produced small mutagenic effect. After UV‐irradiation pigment mutants developed for the most part and a combination of UV‐ and x‐ray‐irradiation mainly influenced the growth rate. A combination of UV‐irradiation with MNNG elicited the highest number of mutants with increased GA3 production.

Gibberellic acid by solid state fermentation: Consistent and improved yields

Five strains each of Gibberella fujikuroi and Fusarium monoliforme were screened to select G. fujikuroi P-3, a strain capable of giving consistent production of gibberellic acid (GA(3)) by solid state fermentation (SSF). The comparative production of GA(3) by SSF and submerged fermentation (SmF) indicated better productivity with the former technique. The accumulation of GA(3) was 1.626 times higher in the case of SSF. On the basis of available carbohydrates in the media, the percent conversions were 0.096 and 0.156 in SmF and SSF, respectively. The use of coarse wheat bran of the particle size of 0.3-0.4 cm resulted in an increase of 2.5 times in the yield of GA(3). The enrichment of commercial wheat bran with soluble starch gave enhanced accumulation to an extent of 3.5 times. The relation between GA(3) production and cell growth in SSF was similar to that encountered in SmF. The consistent and improved yields to a tune of 1.22 g GA(3) per kilogram dry moldy bran (DMB) establish the potential and feasibility of SSF for the production of GA(3) by G. fujikuroi P-3. On preliminary cost analysis, a net savings of about 60% and 50% on fermentation medium cost and the expenditure on down-stream processing, respectively, as compared to the presently employed SmF technique was evident.

Gibberellin Biosynthesis: Genetic Studies in Gibberella fujikuroi

AbstractBiochemical genetic studies on the production of gibberellins by the fungus Gibberella fujikuroi have identified two genes which control different steps in the biosynthetic pathway. One gene (g1) controls the production of all of the gibberellins: the second gene (g2) controls the production of GA1 and GA3 only.Ascospores are not ordered in the ascus of this fungus. This apparent spore slippage precludes mapping of these genes to their respective centromeres.

INFLUENCE OF THE SOYA MEAL FRACTIONS ON GIBBERELLIC ACID AND GIBBERELLIN A PRODUCTION IN SUBMERSE CULTIVATION OF GIBBERELLA FUJIKUROI.

The relationship of different soya meal components to gibberellin (GA) production was studied. Fluorometric assay confirmed that under the given fermentation conditions, only gibberellic acid (GA3) was synthesized on medium containing corn steep. On substituting soya flour for corn steep, the same amount of GA3 was produced and in addition gibberellin A (GA1) was formed. The GA3: GA1 ratio was 1∶1. The course of fermentation in media containing the soya meal protein fraction (fraction I), the soya meal amino acid complex, the corn steep amino acid complex and individual amino acids (γ-aminobutyric acid or tryptophane) was the same as in the control medium containing soya meal. The soya meal fraction II, which is characterized by a high cellulose and carbohydrate content, raised GA production by 25% as compared with production in medium containling soya meal; it simultaneously stimulated GA3 production, so that the final GA3: GA1 ratio was 4∶1.