Effects of Cotton Seed Powder as the Seed Medium Nitrogen Source on the Morphology and Pneumocandin B0 Yield of Glarea lozoyensis

Abstract

Pneumocandin B0 is an important antifungal drug precursor produced by filamentous fungus Glarea lozoyensis. The high broth viscosity of cultures of this organism results in lower oxygen solubility and higher energy consumption for agitation and aeration, which mostly caused by the morphologies of filamentous fungi in submerged culture. In this study, the effects of different seed medium nitrogen sources on morphology and fermentation behavior of G. lozoyensis were investigated, and cotton seed powder resulted in small, compact pellets. Moreover, pneumocandin B0 yield in Erlenmeyer flasks were increased by 22.9%. Furthermore, pneumocandin B0 yield in a 50-L fermenter reached 2,100 mg/L and the dissolved oxygen maintained above 30%. Additionally, activities of phosphofructokinase (PFK), isocitrate dehydrogenase (ICDH), glucose 6-phosphate dehydrogenase (G6PDH), and malic enzyme (ME) were increased by 87.5, 50, 41.6, and 10.7%, respectively. This study demonstrates the feasibility and advantages of using cotton seed powder for controlling the fungal morphology and improving the product yield in pneumocandin fermentations.

Improvement of natamycin production by controlling the morphology of Streptomyces gilvosporeus Z8 with microparticle talc in seed preculture

“…Young spores (age 8 and 12 days on slant) tended to form small compact seed pellets with hairy superficial mycelia, which yielded a higher natamycin titer in the subsequent fermentation. This morphology was in good agreement with the seed mycelial shape for the highest pneumocandin B 0 production, 30 implying that this seed morphology might be generally suitable for antibiotic biosynthesis. Conversely, older spores (exceeding 16 days) led to larger mycelial pellets with little superficial mycelia, accompanied by a significant decline in natamycin titer, biomass concentration and glucose utilization.…”

“…Morphology regulation has been successfully used in fermentations by filamentous bacteria and fungi; 20–30,35–38 however, there is little research on its application in the seed preculture process. To improve the natamycin production, different amount of microparticle talc was added in seed preculture from 8‐ and 28‐day spores to modify the morphology of the mycelial pellets (Fig.…”

“…Nevertheless, most of these strategies have been carried out in formal fermentation rather than seed preculture process; hence there are certain limitations regarding its application. As it is found that the seed mycelial morphology exerts a significant influence on the following fermentation performance in pneumocandin B 0 production, 30 precise regulation of seed morphology is expected to be an effective approach to the further improvement of natamycin production.…”

Insight into advances for the biosynthetic progress of fermented echinocandins of antifungals

“…Regarding carbon and nitrogen sources, the combination of mannitol and glucose as co‐fermentation carbon sources proves most favourable for pneumocandin B 0 biosynthesis, resulting in a 65% increase in its yield (Qin et al., 2016 ). Moreover, the incorporation of cotton seed powder as the nitrogen source in the seed culture medium leads to a 23% enhancement in pneumocandin B 0 production (Song et al., 2018 ). For the biosynthesis of echinocandin B, the highest titre of 2133 mg/L, which is twice higher than that of mannitol, was obtained by using methyl‐oleate as a carbon source (Niu et al., 2020 , 2021 ; Zou et al., 2015 , 2019 ).…”