A Study on the Effect of Lactobacillus spp. on the Growth and Citrinin production by Penicillium citrinum

Penicillium citrinum 생육과 citrinin 생성에 미치는 젖산균의 영향에 관한 연구

ABSTRACT - This study was performed to investigate the possible effect of Lactobacillus spp. on the growth and citrinin production by Penicillium citrinum. Lactobacillus bulgaricus and Lactobacillus casei were grown with Pen. citrinum in modified APT broth containing 7% of glucose and incubated at $30^{\circ}C$ for 15 days. Four inoculation procedures were used; (a) Lactobacillus spp. and Pen. citrinum were grown alone(Pc, Lb, and Lc), (b) both organisms were added simultaneously(ST; Pc+Lb and Pc+Lc), (c) Lactobacillus spp. was grown 3 days, then conidia of Pen. citrinum were added(LbPc and LcPc), and (d) Pen. citrinum was grown 3 days, then Lactbacillus spp. was added (PcLb and PcLc). At 0, 3, 6, 9, 12, 15 days of incubation, the growth of each organism, pH and total acidity of broth, and content of citrinin were determined. Lactobacillus spp. and Pen. citrinum, when grown associatively, influenced the growth of each other. It was observed that slower growth of Pen. citrinum when in the presence of Lactobacillus spp. than when the mold grew alone. Production of citrinin by Pen. citrinum was markedly less in the mixed culture. No apparent growth and toxin production was observed when the Lactobacillus spp. was grown 3 days, then conidia of Pen. citrinum were added(LbPc and LcPc). The above results indicate that another microorganism or competing microflora in the culture can affect the behavior of Pen. citrinum.trinum.

Penicillium citrinum의 생육과 citrinin 생성에 젖산균이 미치는 영향을 조사하기 위하여 Penicillium citrinum을 치이즈 열성균인 Lactobacillus casei 및 Lactobacillus Bulgaricus와 혼합배의를 실시하였다. 즉 glucose를 7% 첨가한 APT 배지에 공식균을 각각 독립배의한 경우(Pc, Lb 및 Lc) , Penicillium citrinum 과 Lactobacillus spp.를 동시에 접종, 배양한 경우(ST; Pc＋Lb 및 Pc＋Lc) , Lactobacillus spp.를 접종하여 3일간 배양한 후 Penicillium citrinum을 접종하여 배양한 경우(LbPc 및 LcPc), 그리고 Penicillium citrinum을 접종하여 3일간 배양한 후 Lactobacillus spp.를 접종하여 배양한 경우 (PcLb 및 PcLc)로 구분하여 각각 30℃에서 15일간 정식 배의하면서 경시적으로 (0, 3, 6, 9, 12, 15일) 배의 액의 pH와 산도를 측정하고 공식균의 생육과 citrinin 생성을 비교하였다. 그 결과 , 균의 생육은 혼합배의 의 경우 Penicillium citrinum의 성장이 크게 둔화되었고 특히 젖산균을 먼저 접종한 군(PcLb 및 PcLc)의 경우 더욱 현저히 나타났다. Citrinin의 생성은 곰팡이 대조군(Pc)과 곰팡이를 먼저 접종한군(PcLb 및 PcLc) 에서는 비슷한 함량을 보였으나 곰팡이와 세균을 동시 접종한 경우 (ST) 감소되었고, 특히 Lactobacillus spp. 배양 후 Penicillium citrinum을 접종한 군(LbPc 및 LcPc)에서는 citrinin 생성이 나타나지 않아 Penicillium citrinum의 생육과 citrinin 생성이 경쟁적으로 작용하는 microflora에 의해 큰 영향을 받는 것으로 나타났다.