Yield Of GA3 Research Articles

Improving the productivity of gibberellic acid by combining small-molecule compounds-based targeting technology and transcriptomics analysis in Fusarium fujikuroi

Gibberellic acid (GA3), produced industrially by Fusarium fujikuroi, stands as a crucial plant growth regulator extensively employed in the agriculture filed while limited understanding of the global metabolic network hinders researchers from conducting rapid targeted modifications. In this study, a small-molecule compounds-based targeting technology was developed to increase GA3 production. Firstly, various small molecules were used to target key nodes of different pathways and the result displayed that supplement of terbinafine improved significantly GA3 accumulation, which reached to 1.08 g/L. Subsequently, lipid and squalene biosynthesis pathway were identified as the key pathways influencing GA3 biosynthesis by transcriptomic analysis. Thus, the strategies including in vivo metabolic engineering modification and in vitro supplementation of lipid substrates were adopted, both contributed to an enhanced GA3 yield. Finally, the engineered strain demonstrated the ability to achieve a GA3 yield of 3.24 g/L in 5 L bioreactor when utilizing WCO as carbon source and feed.

Retraction Note: Mutagenesis combined with fermentation optimization to enhance gibberellic acid GA3 yield in Fusarium fujikuroi

Retraction Note: Mutagenesis combined with fermentation optimization to enhance gibberellic acid GA3 yield in Fusarium fujikuroi

RETRACTED ARTICLE: Mutagenesis combined with fermentation optimization to enhance gibberellic acid GA3 yield in Fusarium fujikuroi

Gibberellic acid (GA3) is a plant growth hormone that plays an important role in the production of crops, fruits, and vegetables with a wide market share. Due to intrinsic advantages, liquid fermentation of Fusarium fujikuroi has become the sole method for industrial GA3 production, but the broader application of GA3 is hindered by low titer. In this study, we combined atmospheric and room-temperature plasma (ARTP) with ketoconazole-based screening to obtain the mutant strain 3-6-1 with high yield of GA3. Subsequently, the medium composition and fermentation parameters were systematically optimized to increase the titer of GA3, resulting in a 2.5-fold increase compared with the titer obtained under the initial conditions. Finally, considering that the strain is prone to substrate inhibition and glucose repression, a new strategy of fed-batch fermentation was adopted to increase the titer of GA3 to 575.13 mg/L, which was 13.86% higher than the control. The strategy of random mutagenesis combined with selection and fermentation optimization developed in this study provides a basis for subsequent research on the industrial production of GA3.Graphical

Improvement of gibberellin production by a newly isolated Fusarium fujikuroi mutant.

To obtain and investigate the potential mechanism for GA3 production in Fusarium fujikuroi GA-251, a high GA3 producer. Fusarium fujikuroi IMI 58289 was bred with Cobalt-60 (60 Co) radiation and lithium chloride treatment. The best mutant strain GA-251 was obtained for the subsequent optimization of fermentation conditions. The yield of GA3 by GA-251 was 2100mgl-1 , while the wild-type strain was 100mgl-1 , which is a 21-fold increase in the yield. To elucidate the mechanism of high GA3 yield of GA-251, the genome was sequenced and compared with wild-type strain IMI 58289. The results showed 2295 single nucleotide polymorphisms, 1242 small indels and 30 structural variants. These mutations were analysed and enriched in the MAPK signalling pathway, the mRNA surveillance pathway and endocytosis. The potential reasons for the improved GA3 biosynthesis were investigated. The potential mechanism of high GA3 yield was attributed to endocytosis pathway and histone modification proteins family. A mutant strain GA-251 in this work that could potentially be utilized in the industrial yield of GA3 . The comparative genome analysis would shed light onto the mechanism of yield improvement and be a theoretical guide for further metabolic engineering.

Enhancement of gibberellic acid production from Fusarium fujikuroi by mutation breeding and glycerol addition.

Gibberellic acid (GA3) is a natural plant growth hormone that has been widely used in agriculture and horticulture. To obtain higher GA3 producing strains, the method of screening the strains for resistance to simvastatin was used after treatment with nitrosoguanidine (NTG) and gamma rays. The rationale for the strategy was that mutants showing simvastatin resistance were likely to be high GA3 producers, as their activity of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase is relatively more effective. GA3 yield of mutant S109 increased by 14.2% than that of the original strain. The GA3 production ability in mutant S109 remained relatively stable after ten generations. With the addition of 0.4g glycerol on the 5th day during the fermentation process in Erlenmeyer flask, maximum GA3 production of 2.7g/L was achieved by this mutant, exhibiting 28.6% increase compared with original strain. Furthermore, we also achieved 2.8g/L GA3 and had a 33.3% increase with addition 20g glycerol on the 5th day during the fermentation process in a 5-L bioreactor. Our results indicated efficient GA3 production could be achieved on the condition that the supply of glycerol at the suitable conditions. This study would lay a foundation for industrial production of GA3.

Gibberellic acid production from Gibberella fujikuroi using agro-industrial residues

Abstract Gibberellic acid (GA3) was produced from Gibberella fujikuroi by solid-state fermentation (SSF) using a mixture of two agro-industrial wastes: rice bran and malt residue. The crude rice bran (CRB):malt residue (MR) proportion in the solid substrate, the moisture content, and the inorganic nitrogen amount were the parameters evaluated on the GA3 yield. After 7 days of cultivation, the highest GA3 yield was 934.41 mg/kg of substrate in optimum condition (65.95% of moisture, CRB:MR proportion (10:90 (wt.%)), and 1.60 g of inorganic nitrogen/kg of substrate). The best condition was used to determine the GA3 kinetic profile, being its maximum production of 1300 mg/kg of substrate after 10 days of fermentation. Therefore, the rice bran and malt residue mixture proved to be a promising substrate for the GA3 production by SSF.

A New Endophytic Fusarium Oxysporum Gibberellic Acid: Optimization of Production Using Combined Strategies of Experimental Designs and Potency on Tomato Growth under Stress Condition.

This study reports the potential of the endophytic fungi identified as a Fusarium oxysporum to produce gibberellic acid (GA3). The GA3 production was confirmed by high performance liquid chromatography. To improve the production of this phytohormone under solid state fermentation (SSF), successive optimization strategies were used. Firstly, Plackett-Burman design was applied for screening medium components and culture condition. Under the optimized condition, GA3 yield (7.14 g/kg) was 2.62-fold higher than by the use of the initial condition (2.72 g/kg). The concentration of the most influential parameters and their interaction were optimized with a Box-Behnken experimental design. The optimized condition led to a 1.14-fold enhancement in GA3 production, reaching 8.16 g/kg. The GA3 crude extract obtained by SSF was then used to study its ameliorative role on adverse salinity effect on tomato plants (Solanum lycopersicum L.). The interactive effects of different GA3 concentrations were examined on morphological and physiological parameters of tomato plants. The application of GA3 (10−6 M) under salt stress condition (100 mM) was found to improve growth and physiological parameters including plant height, total chlorophyll, starch, and proline contents. The exogenous application of GA3 is a potent strategy to reverse abiotic stress that affect the agricultural productivity and limit plant growth and yield.

Screening and Development of Effective Mutants of Fusarium fujikuroi for enhanced Gibberellic Acid Production

Gibberellins (GAs) are a group of diterpenoid acids with ent-gibberellane skeleton that function as plant growth regulators influencing a range of devel- opmental processes in higher plants including stem elongation, germination, dormancy, flowering, sex expression, enzyme induction, leaf and fruit senes- cence (Graebe and Ropers, 1978). Gibberellic acid is a high value, industrially important biochemical, sell- ing high rate in the international market depending on the purity and potency. Gibberellic acid also has potential application in improving seedling establish- ment and seed production in hybrid rice (Carlson et al., 1992). In India up to 1970’s research on gibberel- lic acid mainly focused on the isolation and identifi- cation of GAs from plant sources. Studies conducted at CFTRI, Mysore in 1970s ended with a GA3 yield of0.40 - 0.45 g per litre in submerged fermentation pro- cess (SmF) even after optimizing the culture condition parameters. The efficient strain selection and usage plays key role to make the gibberellic acid production economically viable. The strain improvement strategy for increased GA production can be achieved by mu- tation and protoplast fusion in filamentous fungi like F.fujikuroi. In the present work, we have screened and developed a procedure to obtain effective F.fujikuroi mutants through physical and chemical mutagenesis for increased gibberellic acid production.

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.

Separation of gibberellic acid (GA3) by macroporous adsorption resins

The adsorption effects of several macroporous adsorption resins for gibberellic acid (GA3) were investigated. The dynamic adsorption capacity is 58.38 mg/g dry beads for resin R4 and 96.46 mg/g dry beads for resin R5 which is consistent with the surface area. Aqueous methanol (50%, V/V) is a good eluent and the yield of GA3 is above 95%. The concentration of GA3 could increase five-fold after an adsorption-elution cycle and this is important when considering further crystallization of GA3 in an industrial process.

Bioprocess strategies and recovery processes in gibberellic acid fermentation

Gibberellic acid (GA3) is a commercially important plant growth hormone, which is gaining much more attention all over the world due to its effective use in agriculture and brewing industry. Industrially it is produced by submerged fermentation technique using Ascomycetous fungusGibberella fujikuroi. Solid state and immobilized cell fermentation techniques had also been developed as an alternative to obtain higher yield of GA3. This review summarizes the problems of GA3 fermentation such as production of co-secondary metabolites along with GA3, substrate inhibition and degradation of GA3 to biologically inert compound gibberellenic acid, which limits the yield of GA3 in the fermentation medium. These problems can be overcome by various bioprocessing strategiese.g. two-stage and fed batch cultivation processes. Further research on bioreactor operation strategies such as continuous and/or extractive fermentation with or without cell recycle/retention system need to be investigated for improvement in yield and productivity. Down stream processing for GA3 isolation is also a challenge and procedures available for the same have been critically evaluated.

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.

Separation of gibberellic acid (GA3) by macroporous adsorption resins

Adsorption rates of gibberellic acid (GA3) on S-8 and X-5 resins were measured with the results indicating that the adsorption attained equilibrium for adsorption times longer than 4 h. The adsorption isotherms of GA3 on AB-8, X-5, S-8, D4020, D3520, D4006 and NKA-9 were determined at 20 °C. S-8 resin had the largest solid/liquid distribution coefficient of 10.5 and was selected as the adsorbent for separation of GA3 from the aqueous solution. The breakthrough curves of GA3 from the aqueous solution on S-8 resin were determined at different flow rates. The dynamic adsorption capacity of GA3 was measured as 4.56 mgg−1 wet resin at a flow rate of 0.5 cm3min−1. GA3 adsorbed on S-8 resin was eluted with several eluents with 80% (v%) acetone aqueous solution having the best desorption performance. When GA3 was adsorbed by S-8 resin from the fermentation liquor, the dynamic adsorption capacity of GA3 was increased to 12.02 mgg−1 wet resin in virtue of the salting-out effect of the ammonium sulfate in the fermentation liquor. The yield of GA3 was above 90% after GA3 was adsorbed by S-8 resin from the fermentation liquor at pH 2 and eluted by 80% (v%) acetone aqueous solution. The GA3 concentration was increased seven-fold from the fermentation liquor after an adsorption and desorption cycle. © 2000 Society of Chemical Industry

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.

Solid state fermentation: physical and nutritional factors influencing gibberellic acid production

The production of gibberellic acid (GA3) was found to be influenced by physical and nutritional factors. The nutritional factors studied were the urea nitrogen and MgSO4 concentrations, whereas the physical factors were moisture content, autoclaving time, inoculum ratio and moist medium to culture flask volume ratio. The yield of GA3 was improved 2.9 times by judicious selection of these parameters. Thus, the increase in GA3 yield in the wheat bran medium reduces the expense on medium and further leads to reduction of the overall cost of production.

Enhancement of Berberine Production in Suspension Cultures of Coptis japonica by Gibberellic Acid Treatment

The production of berberine by cell cultures of Coptis japonica was enhanced by the addition of gibberellic acid (GA3 10 −8 –10 −5 M) to the medium, particularly in the early stages of the culture period. After 14 days of culture the berberine yield of GA3 treated cells (10 −8 M) was 1660 mg·1 −1 suspension, controls 1230 mg·l −1 . Also, the addition of gibberellic acid suppressed the starch synthesis in the late exponential growth phase. Furthermore, the addition of gibberellic acid altered the rates of incorporation of sucrose and nitrogen into the cells during the early stage of culture. The results suggest that the change in the incorporation rate of main nutrients triggered by gibberellic acid has a marked effect on the synthesis and accumulation of berberine.

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.