ABSTRACT
Abstract Chaetoglobosin A is an antibacterial compound produced by Chaetomium globosum, with potential application as a biopesticide and cancer treatment drug. The aim of this study was to evaluate the feasibility of utilizing cornstalks to produce chaetoglobosin A by C. globosum W7 in solid-batch fermentation and to determine an optimal method for purification of the products. The output of chaetoglobosin A from the cornstalks was 0.34 mg/g, and its content in the crude extract was 4.80%. Purification conditions were optimized to increase the content of chaetoglobosin A in the crude extract, including the extract solvent, temperature, and pH value. The optimum process conditions were found to be acetone as the extractant, under room temperature, and at a pH value of 13. Under these conditions, a production process of the antifungal chaetoglobosin A was established, and the content reached 19.17%. Through further verification, cornstalks could replace crops for the production of chaetoglobosin A using this new production process. Moreover, the purified products showed great inhibition against Rhizoctonia solani, with chaetoglobosin A confirmed as the main effective constituent (IC50 = 3.88 µg/mL). Collectively, these results demonstrate the feasibility of using cornstalks to synthesize chaetoglobosin A and that the production process established in this study was effective.
Subject(s)
Industrial Microbiology/methods , Callosities/microbiology , Chaetomium/metabolism , Indole Alkaloids/metabolism , Antifungal Agents/metabolism , Waste Products/analysis , Industrial Microbiology/instrumentation , Callosities/metabolism , Molecular Structure , Plant Stems/metabolism , Plant Stems/microbiology , Indole Alkaloids/isolation & purification , Indole Alkaloids/chemistry , Antifungal Agents/isolation & purification , Antifungal Agents/chemistryABSTRACT
A technique for rearing Elasmopalpus lignosellus (Zeller),larvae in laboratory, infesting plants in the field and evaluating treatments was described and tested in rice. In addition, the performance of insecticides as seed treatments to control larvae, under artificial and natural infestations, was evaluated on three planting dates. The experimental design was a Latin 6x6 square and the experimental unit consisted of seven 4 m long rows and 0.4 m spacing between rows. Treatments consisted of the following insecticides and doses: thiamethoxam (52.5, 70, and 105 g a.i./100 kg seeds), furathiocarb (320 g a.i./100kg seeds), carbofuran (525 g a.i./100kg seeds), and an untreated control. Artificial infestations were made, in two groups of three selected tillers at the border rows in each plot and confined in PVC cylinders on three dates of each planting. Tillers were infested with three 7-day old E. lignosellus larvae. Immediately after infestation, cylinders containing three rice tillers were protected to avoid the effect of rain on the larvae. Damage was evaluated 20 days after the infestations. Artificial infestations increased the damage 32 fold, in relation to natural infestations in the untreated control. Insecticides reduced larval survival significantly for 60 days after planting compared to the untreated control.
Uma técnica para produzir lagartas Elasmopalpus lignosellus (Zeller), no laboratório, infestar plantas em campo e avaliar tratamentos foi descrita e testada em arroz. A ação de inseticidas para tratamento de sementes no controle da lagarta elasmo, utilizando infestação artificial e natural, também foi avaliada em experimentos de três datas de plantios. O delineamento experimental foi quadrado latino 6x6. A unidade experimental era formada de sete fileiras de arroz de 4 m de comprimento, espaçadas de 0,4 m. Os tratamentos consistiram dos seguintes inseticidas e doses: tiametoxam (52,5; 70 e 105 g i.a./100 kg sementes), furatiocarbe (320 g i.a./100kg sementes), carbofuram (525 g i.a./100 kg sementes) e testemunha não tratada. Infestações artificiais foram realizadas em dois grupos de três colmos, selecionados nas fileiras bordadura das parcelas e confinados em cilindros de PVC, em três datas de cada plantio. Colmos de cada cilindro foram infestados com três lagartas de E. lignosellus com sete dias de idade. Imediatamente após as infestações, os cilindros contendo três colmos de arroz foram protegidos do efeito das chuvas sobre as lagartas. Os danos foram avaliados 20 dias após as infestações. Infestações artificiais usadas neste estudo aumentaram o dano em 32 vezes, em relação à infestação natural das testemunhas. Inseticidas reduziram significativamente a sobrevivência de larvas até 60 dias após o plantio, comparados com a testemunha.