Potensi Cendawan Endofit sebagai Pengendali Hayati Penyakit Busuk Pangkal Batang (Phytophthora capsici) pada Bibit Cabai

Stem rot disease caused by Phytophthora capsici is an important disease on chilli. Eight endophytic fungi that had been isolated and screened based on pathogenecity test were further tested for their potential as the biological control agent of the stem rot disease of chilli. The endophytic fungi suspension was applied twice during the trial. The first application was on 100 seed lot, by soaking them in 100 mL of suspension. The second application was on the 3 weeks-old chili seedlings by drenching them with 10 mL suspension per plant. The concentration of endophytic fungi in the suspension was 2.8 × 106 cfu mL-1. The disease intensity and AUDPC value were measured for 4 weeks after the pathogen inoculation. The growth inhibition test of P. capsici was performed in vitro and the colonization abilities of endophytic fungi were observed at 4 weeks-old chilli seedlings. Eight endophytic fungi inhibited the growth of the P. capsici, and two of those isolates namely Penicillium strain MAG1 and Penicillium strain PAB2 showed antibiosis mechanism. Endophytic fungi has the ability more to colonize at the root (26–60%) than in the stem (20–40%). Fusarium strain MAGR1 has the highest level of endophytic colonization i.e. 60% compared to others. Based on in vivo assay, six endophytic fungi isolates, i.e. Fusarium strain MAGR1, Penicillium strain MAG1, Penicillium strain PAB2, sterile hyphae HAJ1, sterile hyphae HAJ2, and sterile hyphae PBG7, showed the potency to control stem rot disease with inhibition level of 25.5–35.5%

Antifungal activity of chitosan and its quaternized derivative in gel form and as an edible coating on cut cherry tomatoes

The antifungal activities of medium molecular weight chitosan and its hydrosoluble derivative salt N,N,N-trimethylchitosan were examined as both gel and as a solid protective coating against three common food spoilage fungi (Penicilliumsp., wild Aspergillussp. and one standard strain of Aspergillusflavus). The salt derivative is characterized by having permanent positive charges and is expected to have a higher antimicrobial activity than commercial chitosan. In gel form, the minimum inhibitory concentration (MIC) resulted in the same value for both polymers against all tested fungi (> 2.0 gl-1). The derivative presented a significant fungistatic action against the Penicillium strain within the concentration range of 0.2 to 0.6 gl-1. When applied as protective coatings on freshly cut cherry tomatoes, the commercial chitosan appeared to be more effective in forming stable films and preventing fungal infestation than its derivative. Less than 20?25% of samples were infected after one week of incubation when compared to control (uncoated) and chitosan treated samples.

Screening of Wild-Type Fungal Isolates for Cellulolytic Activity

Background In this study, wild-type fungal isolates, producing highly effective cellulolytic enzymes were selected for bioconversion of residues and waste from agriculture and rational utilization of energy resources for food production. Methods We screened wild-type fungal isolates of Aspergillus, Penicillium, and Trichoderma with an enhanced ability to produce extracellular cellulase. We carried out solid-state fermentation on a medium of agricultural waste products, including wheat bran, beet peels, and cotton oil cake, as well as additional sources of nitrogen and mineral elements. Enzyme production by the fungal isolates was detected within 14 days of cultivation. Results Of 17 strains of Trichoderma, Aspergillus, and Penicillium tested, we identified Penicillium strain K-2-25 and Trichoderma lignorium strain T-22 to have high cellulolytic activity. K-2-25 demonstrated the highest activity after 48 hours of cultivation. T-22 also showed significant cellulolytic activity. Penicillium strain K-2-25 showed cellulolytic activity for 98–270 hours during cultivation, and the amount of reduced glucose was 945 mg. T. lignorium T-22 was the second most active strain, with glucose reduction of 835 mg. Conclusion The strains K-2-25 and T-22 will are be recommended for biotechnological applications, especially for bioconversion of poor hardly decomposable vegetable waste products, such as like straw, into useful biomass.

Eighty Years after Its Discovery, Fleming's Penicillium Strain Discloses the Secret of Its Sex

ABSTRACT Eighty years ago, Alexander Fleming discovered antibacterial activity in the asexual mold Penicillium, and the strain he studied later was replaced by an overproducing isolate still used for penicillin production today. Using a heterologous PCR approach, we show that these strains are of opposite mating types and that both have retained transcriptionally expressed pheromone and pheromone receptor genes required for sexual reproduction. This discovery extends options for industrial strain improvement programs using conventional genetical approaches.