Levels of beauvericin (BEA) and enniatins (ENNs: ENA, ENA1, ENB, and ENB1) were examined in fresh ginger (n = 43) and ginger powder (n = 31) samples from Korea. In the ginger samples, incidence of BEA contamination was highest, at 62.79%, with a maximum detected BEA level of 640.07 μg/kg. ENNs in were found in up to 11.63% (ENB, ENB1) of ginger samples, with a maximum detected level of 91.02 μg/kg (ENA). In the ginger powders, ENB contamination displayed the highest rate of incidence (70.97%), but the highest level of BEA (1,344.18 μg/kg) exceeded that of ENB (413.99 μg/kg). The incidences of ENA, ENA1, ENB, and ENB1 presence in ginger powders were 29.03%, 22.58%, 70.97%, and 35.48%, respectively, and their highest detected levels were 220.45, 156.61, 413.99, and 70.29 μg/kg, respectively. The incidence of BEA and ENN contamination was higher in ginger powder than in ginger. Respective co-occurrence rates of BEA and ENNs in ginger and ginger powder samples were 16.28% and 64.52%, indicating that the BEA and ENN co-contamination rate was highest in ginger powder as well. This is the first report on the presence and co-occurrence of BEA and ENNs in Korean ginger and ginger powder.

Beauvericin (BEA) is a cyclohexadepsipeptide produced by the fungus Beauveria bassiana. And it has been reported to have very effective anti-cancer activity. However, the mechanistic studies of BEA on cytotoxicity on cancer cells have not been fully understood. In this study, we examined the cytotoxicity of BEA on the C6 (rat glioma cell line). The cell viabilities of C6 cells, MDA-MB 231 (breast cancer cell line), and HeLa (cervical cancer cell line) were decreased by treatment of BEA. In addition, BEA-treated cells showed membrane blebbings and buddings, which indicates that BEA decreased cell viability by inducing apoptosis. Additionally, we found that the level of apoptosis inducing molecules such as caspase 3, caspase 9 of BEA treated cells was increased and apoptosis regulating molecules (Bcl-2) was decreased. We also found that the activated STAT3 and Src was decreased in BEA-treated condition. In further study, we are going to find out how the BEA can influence Src kinase activity.

Cordyceps bassiana (asexual stage Beauveriabassiana) is a widely distributed entomopathogenic fungus that infects hundreds of various insects. It produces a number of secondary metabolites, including insect toxins beauvericin and bassianolide and pigment tenellin. In the present study, members of NRPS and PKS-NRPS hybrid genes were predicted from whole genome sequences of eighteen different fungal species belonging to five families of Hypocreales (Cordycipitaceae, Clavicipitaceae, Ophiocordycipitaceae, Hypocreaceae and Nectriaceae) using antiSMASH ver. 1.2.2. Phylogeny using all predicted adenylation (A) domains was drawn in order to identify potential orthologous genes of beauvericin synthetase (BbBEAS) and bassianolide synthetase (BbBSLS) in Hypocreales. The orthologs were examined to understand the evolution of beauvericin and bassianolide synthetase genes. Phylogenetic tree shows grouping of A1 and A2 domains of BbBEAS, BbBSLS and enniatin synthetases in two separate clades indicating the origin of genes from fusion of two distantly related modules. Species phylogeny of C. bassiana and its allies is congruent with gene trees of BbBEAS and BbBSLS, suggesting that the gene fusion event predates the species divergence. In the inferred phylogeny, A1 domain of BbBEAS showed highest similarity with that of BbBSLS, followed by those of Fusarium equiseti enniatin synthetase and Xylariasp. bassianolide synthetase. Syntenic analysis of beauvericin gene clusters of C. bassiana and closely related species represents that C. militaris lost the BbBEAS gene in evolution. Synteny of bassianolide gene clusters shows the loss of NRPS genes encoding BbBSLS in B. pseudobassiana, Isaria tenuipes, I. farinosa and C. pruinosa. BbBEAS and 2-ketoisovalerate reductase (kivr) genes are found conserved in beauvericin and enniatin synthesizing gene clusters.

Beauvericin과 enniatin H, I, 그리고 MK1688의 생산에 미치는 온도와 수분함량의 효과를 조사하였다. 쌀을 기질로 할 경우 25℃, 40% 수분함량에서 조사된 모든 독소들이 최대로 생산되었으며, 15℃의 온도에서 접종 2주 후 50 μg/g이하의 생성량을 나타내었다. 수분함량 10%에서도 접종 후 6주차에 모든 독소들의 검출이 확인되었으며, 이는 이 독소들이 0.75정도의 낮은 수분활성도에서도 생성될 수 있음을 나타낸다. 한편, 국내에서 생산된 곡류들(65종)에 대하여 Fusarium 독소인 beauvericin의 오염을 분석하였다. 국내에서 수확된 65종의 곡류시료 중 6종의 시료에서 beauvericin오염이 확인되었다. 쌀과 현미에서는 beauvericin이 검출되지 않았으며, 2004년산 옥수수 3종, 2004년과 2005산 보리 시료 각 1종, 그리고 2005년 재배된 밀 1종에서 beauvericin이 검출되었다. 가장 높은 오염도를 보인 것은 옥수수 시료이며, 이 시료에서 0.23 μg/g의 beauvericin이 검출되었다. 국내에서는 beauvericin에 대한 곡류 오염 조사가 이 연구에서 처음으로 이루어졌으며, 국내산 곡류에서도 beauvercin이 검출됨에 따라 지속적으로 오염도를 조사할 필요가 있다.