흰점박이꽃무지 (Protaetia brevitarsis) 유충은 동아시아에서 식용 및 약용으로 널리 사용되고 있다. 흰점박이꽃무지 수요 증가로 인해 유충의 대량 사육 방법이 필요하지만 좁은 공간에서 대량으로 유충을 사육할 경우 곤충 병원성 질병 감염에 취약해진다. Metarhizium anisopliae는 흰점박이꽃무지 유충에 치명적인 곤충 병원성 곰팡이 중 하나이다. 이를 저해하기 위해 항진균 성분이 함유된 옻나무 (Rhus verniciflua Stokes) 추출액을 첨가하였고, 연구 결과 1% 옻나무 추출액을 첨가한 경우 녹강균에 의한 유충의 치사율이 유의미하게 낮았다. 또한 일반톱밥을 급여한 대조구에 비해 옻나무 추출액 처리구에서 유충의 무게가 더 무거웠고 유충 기간이 짧아 지는 것을 확인하였다. 따라서 이 연구를 통해 곤충 병원성 곰팡이에 대한 옻나무 추출액의 항진균 효과를 확인할 수 있었으며 흰점박이꽃무지 유충 사육 시 옻나무 추출액을 첨가 하여 급여한다면 병원성 곰팡이에 의한 유충의 치사율을 낮추고 증체량을 높이는 데 효과가 있을 것이다.

누에는 약제, 면직, 식용, 동물 사료 등에 활용도가 높아 동아시아에서 오랫동안 사육되어 왔다. 뽕잎을 먹고 자란 누에가 사료를 먹고 자란 누에보다 생장주기가 일정하고 더 건강하게 생장한다는 것은 잘 알려진 사실이다. 또한 최근의 연구에 따르면 동물 장내 미생물이 동물의 면역과 생장에 큰 역할을 한다고 알려졌다. 이러한 사실로부터 뽕잎에 존재하는 미지의 미생물이 누에 생장과 면역에 관여할 수 있다는 가설을 세우고 이를 확인하기 위한 연구를 수행하였다. 뽕잎 내생균을 분리하기 위해 뽕잎을 5mm 크기로 잘라 표면살균 후, 배지에 치상하여 자라나오는 세균을 분리하여 동정하였다. 흥미로운 점은 100개 이상의 뽕잎 절편으로부터 동일한 세균이 검출되었으며 계통학적 분석을 통해 동정한 결과, Pseudomonas syringae pv. syringae(Pss)로 확인되었다. 또한, 뽕잎을 섭식한 누에의 장 속과 분변에서 이 균의 존재를 확인하였다. 누에에 병을 일으키는 곤충병원성 곰팡이에 대한 Pss의 항진균 효과를 확인하기 위해 곤충병원성 곰팡이인 Beauveria bassiana, Cordyceps militaris와 식물병원성 곰팡이 Botrytis cinerea, Fusarium graminearum을 대상으로 대치배양을 통해 균사 생장 억제 정도를 확인하였다. 그 결과, 식물병원성 곰팡이의 생장 억제효과는 관찰되지 않았으나 곤충병원성 곰팡이의 생장이 50% 이상 감소되었다. 특히, 다량의 포자를 생성하여 곤충에 치명적인 병을 야기하는 B. bassiana의 균사 생장이 C. militaris에 비해 더 크게 감소하였을 뿐 아니라 Pss의 배양 추출물을 처리하였을 때 B. bassiana의 포자 발아가 지연되었다. 앞으로 누에 장 속에 안착한 Pss가 곤충병원성 곰팡이에 대한 면역력과 누에 생장에 미치는 영향을 확인해 볼 계획이며 이를 통해 건강하고 안정적인 누에 사육에 활용될 수 있는 미생물 제제를 만들고자 한다.

Lactic acid bacteria (LAB) producing phenyllactic acid (PLA), which is known as antimicrobial compound, was isolated from button mushroom bed and the isolated LAB was identified to Lactobacillus casei by 16 rRNA gene sequence analysis. Cell-free supernatant (CFS) from L. casei was assessed for both the capability to produce the antimicrobial compound PLA and the antifungal activity against three fungal pathogens (Rhizoctonia solani, Botrytis cinerea, and Collectotricum aculatum). PLA concentration was investigated to be 3.23 mM in CFS when L. casei was grown in MRS broth containing 5 mM phenylpyruvic acid as precursor for 16 h. Antifungal activity demonstrated that all fungal pathogens were sensitive to 5% CFS (v/v) of L. casei with average growth inhibitions ranging from 34.58% to 65.15% (p < 0.005), in which R. solani was the most sensitive to 65.15% and followed by C. aculatum, and B. cinerea. The minimum inhibitory concentration (MIC) for commercial PLA was also investigated to show the same trend in the range of 0.35 mg mL-1 (2.11 mM) to 0.7 mg mL-1 (4.21 mM) at pH 4.0. The inhibition ability of CFS against the pathogens were not affected by the heating or protease treatment. However, pH modification in CFS to 6.5 resulted in an extreme reduction in their antifungal activity. These results may indicate that antifungal activities in CFS was caused by acidic compounds like PLA or organic acids rather than protein or peptide molecules.

The centipede Scolopendra subspinipes mutilans has been a medically important arthropod species by using it as a traditional medicine for the treatment of various diseases. In this study, we derived a novel lactoferricin B like peptide (LBLP) from the whole bodies of adult centipedes, S. s. mutilans, and investigated the antifungal effect of LBLP. LBLP exerted an antifungal and fungicidal activity without hemolysis. To investigate the antifungal mechanism of LBLP, a membrane study with propidium iodide was first conducted against Candida albicans. The result showed that LBLP caused fungal membrane permeabilization. The assays of the three dimensional flow cytometric contour plot and membrane potential further showed cell shrinkage and membrane depolarization by the membrane damage. Finally, we confirmed the membrane-active mechanism of LBLP by synthesizing model membranes, calcein and FITC-dextran loaded large unilamellar vesicles. These results showed that the antifungal effect of LBLP on membrane was due to the formation of pores with radii between 0.74 nm and 1.4 nm. In conclusion, this study suggests that LBLP exerts a potent antifungal activity by pore formation in the membrane, eventually leading to fungal cell death.

Conventional Thiamine Dilauryl Sulfate (TDS) powder has a low stability. In order to solve this problem, this study was performed to improve the solubility of TDS. The process for enhance solubility of TDS was nano grinding mill and ultrasonic dispersion process. TDS paticle was manufactured to nano size through nano grinding mill process. The size of TDS nanoparticle was measured as average 220 nm by DLS. And The TDS nanoparticle in water solution manufactured through ultrasonic dispersion process. The TDS nanoparticle in water solution was showed the highest solubility with 40% ethanol. These results was increased the concentration of TDS from 200 ppm to 240 ppm in water solution. The TDS nanoparticle in water solution showed diameter of Colletotrichum gloeosporioides growth with smaller than about 1.56 cm compared to the TDS paticle in water solution at same concentration. Also, TDS nanoparticle in water solution showed growth inhibition activity as 59.2% with higher than about 10% compared to the TDS paticle water solution in same concentration. Finally, TDS nanoparticle in water solution was increased solubility through nano grinding mill and ultrasonic dispersion process. Also, the increase of concentration in TDS nanopaticle in water solution according to solubility enhancement lead to an result enhancement of antifungal activity. Consequently, we suggested that the TDS nanoparticle in water solution was more effective than TDS particle in water solution owing to the sub-cellular particle size, ability to persistence and targeting to cell membrane of Colletotrichum gloeosporioides. Furthermore we expected the applicating possibility with bio pesticide.