Search published articles
Showing 2 results for Solid-State Fermentation
Volume 0, Issue 0 (1-2024)
Abstract
Poly- gamma- glutamic acid (γ-PGA) is a natural polymer with diverse applications across multiple industries. However, its use in agriculture is limited due to high production costs. This study aimed to optimize the cost-effective production of γ-PGA through Solid-State Fermentation (SSF) using Bacillus velezensis UTB96, evaluate the concentration and molecular weight of γ-PGA suitable for agricultural applications, particularly in strawberry cultivation, and explore the impact of γ-PGA on extending the shelf-life of strawberry fruits during cold storage. Initially, the production of γ-PGA using SSF with B. velezensis UTB96 was investigated, along with an evaluation of the influence of physicochemical factors on the molecular weight of γ-PGA. Based on the results, three different molecular weights of γ-PGA were identified: 1156.43 kDa, 734.38 kDa, and 296.55 kDa. These were selected for greenhouse trials to assess their effectiveness in controlling gray mold on strawberry plants. The results showed that by utilizing agricultural wastes, including sesame flour, wheat straw, and banana peel in SSF methodology, γ-PGA could be produced at a rate of 70 g/kg of dry weight of the culture medium. Analyzing the impact of γ-PGA on reducing gray mold revealed that this compound could enhance the plant's defense. A significant increase in the activity of ascorbate peroxidase and phenylalanine ammonia-lyase (PAL) enzymes was observed, along with the production of polyphenolic compounds such as ellagic acid. Consequently, these mechanisms improved the plant's flexibility and tolerance to the fungus, helping to maintain the quality of the fruits during cold storage.
Sanaz Noori, Parisa Hejazi,
Volume 12, Issue 1 (12-2020)
Abstract
In this study, cellulase enzyme production by Trichoderma reesei on three lignocellulosic substrates (corn bran, sawdust and wheat bran) and percentage of different combinations of sawdust and wheat bran by solid-state fermentation method for 6 days in scale checked out. Then, under optimal substrate component proportions obtained from Erlenmeyer-scale, the effect of aeration at three levels of 0.5, 1 and 1.5 liters per hour of initial dry substrate (l/(h.gds)) on the production of this enzyme in 0.5-Liter packed-bed bioreactor was studied. The initial substrate moisture and pH were 70 %(w/w) and 5 respectively, and the heating temperature was set at Erlenmeyer-scale and bioreactor at 30 and 28 °C, respectively. Cellulase enzyme production was evaluated based on the activity of endoglucanase and exoglucanase enzymes. The highest amount of endoglucanase and exoglucanase activity at substrate combination of 75% wheat bran and 25% sawdust in Erlenmeyer-scale at day 6 and 3 were obtained 13 and 6.4 U/gds, respectively, and in bioreactor at aeration of 1.5 (l/(h.gds)) at day 3 were attained 36 and 10 U/gds, respectively.
