• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.439-449
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• 2017

Beauveria bassiana infects a number of pest species and is known to produce insecticidal substances, such as the nonribosomal peptides (NRPs) beauvericin and bassianolide. However, most NRPs and their biological roles in B. bassiana remain undiscovered. To identify NRPs that potentially contribute to pathogenesis, the 21 predicted NRP synthetases (NRPSs) or NRPS-like proteins of B. bassiana ARSEF 2860 were primarily ranked into three functional groups: basic metabolism (7 NRPSs), pathogenicity (12 NRPSs), and unknown function (2 NRPSs). Based on the transcript levels during in vivo growth on diamondback moth (Plutella xylostella (Linnaeus)), half of the Group II NRPSs were likely to be involved in infection. Given that the metabolites biosynthesized by these NRPSs remain to be determined, our result underlines the importance of the NRPSome in fungal pathogenesis, and will serve as a guide for future genomic mining projects to discover functionally essential and structurally diverse NRPs in fungal genomes.

• Journal of Microbiology and Biotechnology
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• 제24권11호
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• pp.1495-1502
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• 2014

Metarhizium anisopliae is a widely studied model to understand the virulence factors that participate in pathogenicity. Proteases such as subtilisin-like enzymes (Pr1) and trypsin-like enzymes (Pr2) are considered important factors for insect cuticle degradation. In four M. anisopliae strains (798, 6342, 6345, and 6347), the presence of pr1 and pr2 genes, as well as the enzymatic activity of these genes, was correlated with their virulence against two different insect pests. The 11 pr1 genes (A, B, C, D, E, F, G, H, I, J, and K) and pr2 gene were found in all strains. The activity of individual Pr1 and Pr2 proteases exhibited variation in time (24, 48, 72, and 96 h) and in the presence or absence of chitin as the inductor. The highest Pr1 enzymatic activity was shown by strain 798 at 48 h with chitin. The highest Pr2 enzymatic activity was exhibited by the 6342 and 6347 strains, both grown with chitin at 24 and 48 h, respectively. Highest mortality on S. exigua was caused by strain 6342 at 48 h, and strains 6342, 6345, and 6347 caused the highest mortality 7 days later. Mortality on Prosapia reached 30% without variation. The presence of subtilisin and trypsin genes and the activity of these proteases in M. anisopliae strains cannot be associated with the virulence against the two insect pests. Probably, subtilisin and trypsin enzyme production is not a vital factor for pathogenicity, but its contribution is important to the pathogenicity process.

• 한국균학회지
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• 제28권2호
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• pp.112-117
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• 2000

야생에 서식하고 있는 번데기 및 성충에 감염된 기주의 자실체로부터 동충하초속균 3속 14균주를 분리하였고, RFLP에 의한 유전정보를 이용하여 ITS 영역에 대한 유연관계를 분석하였다. 수집된 각 균주의 rDNA ITS I과 II 부위를 primer ITS 1과 ITS 4를 사용하여 PCR에 의해 증폭한 결과 증폭된 산물은 500 bp크기로 잘 보존되어 종간 또는 속간 서로 구분되지 않았다. 따라서 증폭산물을 7종의 제한효소로 절단하여 밴드상을 관찰한 결과 수집된 Paecilomyces tenuipes 4균주와 Beauveria bassiana 2균주, JB3 균주를 제외한 Cordyceps militaris 6균주는 각각 동일 종으로 분류되었다. 한편 C. scarabaeicola 균주는 7종의 제한효소에서 모두 B. bassiana의 밴드와 일치하여 C. scarabaeicola의 불완전세대는 B. bassiana로 간주되었다. 제한 효소 중에 Paecilomyces속과 Cordyceps 속간 구분에 용이한 제한효소는 CfoI, HpaII이었으며, 그중 CfoI는 Paecilomyces, Cordyceps, Beauveria속간 구분에 용이하였다. UPGMA 분석결과 P. tenuipes, C. militaris, C. scarabaeicola와 B. bassiana, JB4 균주 등 4개의 군으로 그룹화되었으며, 그룹간에는 100% 유의수준을 나타냈다. 따라서 rDNA-RFLP 분석에서 속간 유연관계는 적었으나 종간 유연관계는 가까운 결과를 얻었다.