Abstract:
Aureobasidium melanogenum was found to be grown the best at the constant pH 7.0 and to produce the highest amount of liamocins at the constant pH 3.0. Therefore, the wild type strain A. melanogenum 9-1 and the engineered strain V33 constructed in the laboratory were grown at the constant pH 7.0 for 48 h, then, they were continued to be cultivated at the constant pH 3.0. Under such conditions, A. melanogenum 9-1 produced 36.51 ± 0.55 g L-1 of liamocin and its cell mass was 27.43 ± 0.63 and 6.00 ± 0.11 g L-1 of glucose was left in the finished medium within 168 h while the engineered strain V33 secreted 70.86 ± 2.04 g L-1 of liamocin, its cell mass was 31.63 ± 0.74 g L-1 , 0.16 ± 0.01 g L-1 of glucose was maintained in the finished medium. Then, Massoia lactone was released from the produced liamocins. The released Massoia lactone loaded in the nanoemulsions could be used to actively damage cell wall and cell membrane of both spores and mycelia of Aspergillus flavus, leading to its cell necrosis. Massoia lactone loaded in the nanoemulsions also actively inhibited cell growth of A. flavus, its conidia production and aflatoxin biosynthesis on peanuts, indicating that Massoia lactone loaded in the nanoemulsions had highly potential application in controlling cell growth of A. flavus and aflatoxin biosynthesis in foods and feedstuffs.
摘要:
发现黑原金黄色葡萄球菌在恒定pH7.0下生长最佳,在恒定pH3.0下产生最高量的金属霉素。因此,在实验室中构建的野生型菌株A.melanogenum9-1和工程菌株V33在恒定pH7.0下生长48小时,然后,它们在恒定的pH3.0下继续培养。在这样的条件下,A.黑素9-1产生36.51±0.55gL-1的liamocin,其细胞质量为27.43±0.63和6.00±0.11gL-1的葡萄糖在168小时内留在成品培养基中,而工程菌株V33分泌70.86±2.04gL-1的liamocin,其细胞质量为31.63±0.74gL-1,在成品培养基中维持0.16±0.01gL-1的葡萄糖。然后,马苏亚内酯从所产生的美洲霉素中释放出来。纳米乳液中释放的马苏内酯可用于主动破坏黄曲霉孢子和菌丝体的细胞壁和细胞膜,导致其细胞坏死.负载在纳米乳液中的马苏内酯还积极抑制黄曲霉的细胞生长,花生的分生孢子产生和黄曲霉毒素的生物合成,表明纳米乳液中负载的马苏内酯在控制食品和饲料中黄曲霉的细胞生长和黄曲霉毒素的生物合成方面具有高度的潜在应用。