[P004] Poster

1:00 PM - 1:50 PM JST(4:00 AM - 4:50 AM UTC)

[P02-170] Effects of peptone concentration on fumaric acid production by Rhizopus delemar

○Enkang Zhu¹, Kentaro Hiramatsu¹, Atsushi Nishitani², Yumiko Yoshizaki^1,3, Kazunori Takamine^1,3, Masatoshi Goto^1,4, Hisanori Tamaki^1,3, Taiki Futagami^1,3 (1. United Grad. Sch. Agric. Sci., Kagoshima Univ. (Japan), 2. Cent. Adv. Sci. Res. Promot., Kagoshima Univ. (Japan), 3. Fac. Agric., Kagoshima Univ. (Japan), 4. Fac. Agric., Saga Univ. (Japan))

Keywords:

Rhizopus delemar,Fumaric acid,Peptone

Fumaric acid is widely used as a food preservative, acidulant, pH regulator, and flavor enhancer in bread, confectionery, and beverages. It is also an important raw material for unsaturated polyester resins and is utilized in building materials and automotive body panels. The genus Rhizopus is known to produce fumaric acid. Although fumaric acid is currently produced industrially via chemical synthesis from petroleum-derived resources, increasing demand for sustainable manufacturing processes has renewed interest in fermentation-based production using Rhizopus. In this study, we aimed to better understand the factors underlying the high fumaric acid-producing ability of Rhizopus.First, we compared fumaric acid productivity among Rhizopus delemar, Rhizopus oryzae, Rhizopus azygosporus, and Rhizopus microsporus, and selected R. delemar as a fumaric acid producer. Previous studies have shown that carbon and nitrogen sources significantly influence organic acid production by Rhizopus; however, their combined effects remain limited. Therefore, we investigated the effects of glucose and peptone as representative carbon and nitrogen sources, respectively, on fumaric acid production by R. delemar. Supplementation with 5 g/L peptone in media containing either 10 g/L or 80 g/L glucose resulted in different effects on fumaric acid production depending on the glucose concentration. Specifically, peptone supplementation decreased fumaric acid productivity at 10 g/L glucose but increased production at 80 g/L glucose. These results indicate that the balance between carbon and nitrogen availability is an important regulatory factor in fumaric acid fermentation. We next examined the effects of peptone concentrations (0, 1, 2.5, 5, and 10 g/L) on fumaric acid productivity and mycelial yield in medium containing 50 g/L glucose. The results indicated that depletion of peptone inhibited the growth of R. delemar but enhanced fumaric acid productivity. This finding suggests that nitrogen sources are required to support fungal growth, but should be depleted after the growth phase to achieve efficient fumaric acid production. Overall, these findings contribute to the development of sustainable fermentation processes for fumaric acid production using R. delemar.