一株具霉菌抑制活性细菌的鉴定

为探讨菌株HB02对霉菌生长的影响,将HB02与霉菌孢子悬液同时加入到PYG肉汤,在28℃培养15d。在培养的第3、69、、12和15天测定培养液中的黄曲霉和禾谷镰刀菌菌丝重量。结果显示:与对照组相比,HB02可显著抑制黄曲霉和禾谷镰刀菌生长(P<0.01)。通过常规细菌学实验鉴定该菌株为一株乳酸杆菌。通过分子生物学方法测定了菌株的16S rRNA基因序列,进一步证实了HB02为一株乳酸杆菌。根据Berthier等的方法,通过HB0216S/23S rRNA基因间隔(Intergenic Spacer Regions,ISR)序列的扩增和测定,再通过基因文库中所有细菌基因序列比较分析,最终鉴定菌株HB02为一株弯曲乳酸杆菌(Lactobacillus curvatus)。

Identification of a bacterium with activities of inhibiting growth of fungi

HB02 is characterized as a new microbiological agent that has the potential to decrease the toxicity of mildewed wheat containing Deoxynivalenol (DON). To explore whether HB02 could inhibit the growth of fungi, a spore suspension of Aspergillus flavus or Gibberellazeae was incubated with or without HB02 in PYG medium at 28 degrees C for 15d. The mycelium was weighed after 3, 6, 9, 12, 15 d of incubation, respectively. The result showed that the growth of these two important fungi was significantly inhibited by co-cultivation with HB02. Besides, HB02 was confirmed as Lactobacillus curvatus by its microbiological characters and the 16s-23s rRNA sequence. In conclusion, HB02, identified as Lactobacillus curvatus, prevent the effects of mycotoxins in contaminated feed by inhibiting the growth of fungi. Other detoxification ways of HB02 remain further study.