Purpose This study aimed to investigate the effects of different fermentation conditions (culture medium, temperature, incubation time, pH value and additive) on citrinin production by four fungi. Results Among the culture media, potato dextrose medium had lowest citrinin production, followed by yeast sucrose medium and monosodium glutamate medium. The lowest citrinin contents were produced by Monascus anka ( M. anka ) in potato dextrose medium and yeast sucrose medium, Aspergillus oryzae AS3.042 ( A. oryzae ) produced the lowest citrinin production in monosodium glutamate medium. The optimum fermentation temperatures for citrinin production by Aspergillus niger ( A. niger ) and Penicillium citrinum ( P. citrinum ) were at 30 °C, whereas those by M. anka and A. oryzae were at 35 °C. Citrinin synthesis by four fungi were completely inhibited with a pH value of less than 5.4. By adding ethylene diamine tetraacetic acid (EDTA) or triammonium citrate into monosodium glutamate medium, citrinin production by A. oryzae and A. niger were totally inhibited. Ammonium sulfate completely inhibited citrinin production by A. oryzae, M. anka and P. citrinum , and ammonium nitrate completely inhibited citrinin production by A. oryzae . Conclusions These results indicated that the suitable fermentation conditions could make considerable contributions to the reduction of citrinin production. This study provided an effective way for decreasing the citrinin production.

中文翻译：

---

四种不同培养基中产桔霉素的真菌特性及抑制作用

目的 本研究旨在研究不同发酵条件（培养基、温度、孵育时间、pH 值和添加剂）对四种真菌生产桔霉素的影响。结果在培养基中，马铃薯葡萄糖培养基的桔霉素产量最低，其次是酵母蔗糖培养基和味精培养基。Monascus anka (M. anka)在马铃薯葡萄糖培养基和酵母蔗糖培养基中产生的桔霉素含量最低，米曲霉AS3.042 (A. oryzae)在谷氨酸钠培养基中产生最低的桔霉素。黑曲霉(A. niger)和柑橘青霉(P. citrinum)生产柑橘酸的最适发酵温度为30°C，而安卡和米曲霉的最佳发酵温度为35°C。在pH值小于5.4的情况下，四种真菌的桔霉素合成被完全抑制。通过在谷氨酸钠培养基中加入乙二胺四乙酸(EDTA)或柠檬酸三铵，完全抑制米曲霉和黑曲霉产生桔霉素。硫酸铵完全抑制 A. oryzae、M. anka 和 P. citrinum 产生桔霉素，硝酸铵完全抑制 A. oryzae 产生桔霉素。结论这些结果表明，合适的发酵条件可以对降低桔霉素产量做出相当大的贡献。该研究为减少桔霉素的产生提供了一种有效的方法。尼日尔被完全压制。硫酸铵完全抑制 A. oryzae、M. anka 和 P. citrinum 产生桔霉素，硝酸铵完全抑制 A. oryzae 产生桔霉素。结论这些结果表明，合适的发酵条件可以对降低桔霉素产量做出相当大的贡献。该研究为减少桔霉素的产生提供了一种有效的方法。尼日尔被完全压制。硫酸铵完全抑制 A. oryzae、M. anka 和 P. citrinum 产生桔霉素，硝酸铵完全抑制 A. oryzae 产生桔霉素。结论这些结果表明，合适的发酵条件可以对降低桔霉素产量做出相当大的贡献。该研究为减少桔霉素的产生提供了一种有效的方法。