The genus Fusarium can be utilized to produce a great variety of secondary metabolites under specific culture conditions, including pigments of increasing biotechnological interest, such as bikaverin. Such pigments are important due to the biological properties they possess, including antitumor and antibiotic activities, among others. In Fusarium fujikuroi, bik1–bik6 have been identified as the genes that are responsible for the synthesis of bikaverin. Therefore, in this study, we screened for the presence of bik genes and examined changes in mRNA levels of the bik genes under the influence of NH₄NO₃ (0.024, 0.048, 0.50, 1.0, and 4.60 g L⁻¹) and NH₄Cl (0.50 and 1.0 g L⁻¹) as nitrogen sources for the phytopathogen Fusarium oxysporum f. sp. lycopersici. Our results indicated the presence of at least six bik (bik1–bik6) genes and showed increased mRNA levels for bik4, bik5, and bik6 in conditions where NH₄NO₃ was used at pH 3.0. The characteristic coloration of bikaverin was obtained in 10 out of 16 culture conditions, except when the fungus was grown with higher concentrations of NH₄NO₃ (1.0 and 4.60 g L⁻¹). The pigment was chloroform-extracted from the culture conditions of NH₄NO₃ (0.024, 0.048, and 0.50 g L⁻¹) and NH₄Cl (0.50 and 1.0 g L⁻¹) with 3 and 9 days of incubation. Analysis via visible spectroscopy and matrix-assisted laser desorption ionization-time of flight mass spectrometry were used for the identification of bikaverin.

镰刀菌属可用于在特定培养条件下产生多种次生代谢物，包括生物技术兴趣日益增加的色素，例如比卡维林。这种色素很重要，因为它们具有生物学特性，包括抗肿瘤和抗生素活性等。在Fusarium fujikuroi中，bik1-bik6已被确定为负责合成比卡维林的基因。因此，在本研究中，我们筛选了bik基因的存在，并检查了在NH ₄ NO ₃ (0.024、0.048、0.50、1.0 和 4.60 g L ^{-1 ) 影响下}bik基因mRNA 水平的变化。) 和 NH ₄ Cl (0.50 和 1.0 g L ^{-1 ) 作为植物病原体}尖孢镰刀菌f的氮源。sp 。 番茄_ 我们的结果表明存在至少六个bik ( bik1-bik6 ) 基因，并显示在 pH 3.0 使用NH ₄ NO _{3的条件下}bik4、bik5和bik6的mRNA 水平增加。在 16 种培养条件中的 10 种条件下获得了比卡维林的特征着色，除非当真菌在更高浓度的 NH ₄ NO ₃（1.0 和 4.60 g L ^-1）。在培养3天和9天的NH ₄ NO ₃ (0.024、0.048和0.50 g L ^-1 )和NH ₄ Cl (0.50和1.0 g L ^-1 )的培养条件下，用氯仿提取色素。通过可见光谱和基质辅助激光解吸电离-飞行时间质谱分析用于比卡维林的鉴定。